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1 | #include <windows.h> |
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2 | #include <stdio.h> |
3 | #include <stdlib.h> |
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4 | #include <stdarg.h> |
5 | #include <assert.h> |
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6 | |
7 | #include "putty.h" |
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8 | #include "tree234.h" |
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9 | #include "ssh.h" |
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10 | |
11 | #ifndef FALSE |
12 | #define FALSE 0 |
13 | #endif |
14 | #ifndef TRUE |
15 | #define TRUE 1 |
16 | #endif |
17 | |
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18 | #define logevent(s) { logevent(s); \ |
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19 | if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \ |
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20 | { fprintf(stderr, "%s\n", s); fflush(stderr); } } |
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21 | |
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22 | /* logevent, only printf-formatted. */ |
23 | void logeventf(char *fmt, ...) |
24 | { |
25 | va_list ap; |
26 | char stuff[200]; |
27 | |
28 | va_start(ap, fmt); |
29 | vsprintf(stuff, fmt, ap); |
30 | va_end(ap); |
31 | logevent(stuff); |
32 | } |
33 | |
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34 | #define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \ |
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35 | (s ? sk_close(s), s = NULL : 0), \ |
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36 | logeventf msg, connection_fatal msg ) |
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37 | |
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38 | #define SSH1_MSG_DISCONNECT 1 /* 0x1 */ |
39 | #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */ |
40 | #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */ |
41 | #define SSH1_CMSG_USER 4 /* 0x4 */ |
42 | #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */ |
43 | #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */ |
44 | #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */ |
45 | #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */ |
46 | #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */ |
47 | #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */ |
48 | #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */ |
49 | #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */ |
50 | #define SSH1_SMSG_SUCCESS 14 /* 0xe */ |
51 | #define SSH1_SMSG_FAILURE 15 /* 0xf */ |
52 | #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */ |
53 | #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */ |
54 | #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */ |
55 | #define SSH1_CMSG_EOF 19 /* 0x13 */ |
56 | #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */ |
57 | #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */ |
58 | #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */ |
59 | #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */ |
60 | #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */ |
61 | #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */ |
62 | #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */ |
63 | #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */ |
64 | #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */ |
65 | #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */ |
66 | #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */ |
67 | #define SSH1_MSG_IGNORE 32 /* 0x20 */ |
68 | #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */ |
69 | #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */ |
70 | #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */ |
71 | #define SSH1_MSG_DEBUG 36 /* 0x24 */ |
72 | #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */ |
73 | #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */ |
74 | #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */ |
75 | #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */ |
76 | #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */ |
77 | #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */ |
78 | #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */ |
79 | |
80 | #define SSH1_AUTH_TIS 5 /* 0x5 */ |
81 | #define SSH1_AUTH_CCARD 16 /* 0x10 */ |
82 | |
83 | #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */ |
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84 | /* Mask for protoflags we will echo back to server if seen */ |
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85 | #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */ |
86 | |
87 | #define SSH2_MSG_DISCONNECT 1 /* 0x1 */ |
88 | #define SSH2_MSG_IGNORE 2 /* 0x2 */ |
89 | #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */ |
90 | #define SSH2_MSG_DEBUG 4 /* 0x4 */ |
91 | #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */ |
92 | #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */ |
93 | #define SSH2_MSG_KEXINIT 20 /* 0x14 */ |
94 | #define SSH2_MSG_NEWKEYS 21 /* 0x15 */ |
95 | #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */ |
96 | #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */ |
97 | #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */ |
98 | #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */ |
99 | #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */ |
100 | #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */ |
101 | #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */ |
102 | #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */ |
103 | #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */ |
104 | #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */ |
105 | #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */ |
106 | #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */ |
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107 | #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */ |
108 | #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */ |
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109 | #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */ |
110 | #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */ |
111 | #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */ |
112 | #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */ |
113 | #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */ |
114 | #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */ |
115 | #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */ |
116 | #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */ |
117 | #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */ |
118 | #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */ |
119 | #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */ |
120 | #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */ |
121 | #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */ |
122 | #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */ |
123 | |
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124 | /* |
125 | * Packet type contexts, so that ssh2_pkt_type can correctly decode |
126 | * the ambiguous type numbers back into the correct type strings. |
127 | */ |
128 | #define SSH2_PKTCTX_DHGROUP1 0x0001 |
129 | #define SSH2_PKTCTX_DHGEX 0x0002 |
130 | #define SSH2_PKTCTX_PUBLICKEY 0x0010 |
131 | #define SSH2_PKTCTX_PASSWORD 0x0020 |
132 | #define SSH2_PKTCTX_KBDINTER 0x0040 |
133 | #define SSH2_PKTCTX_AUTH_MASK 0x00F0 |
134 | |
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135 | #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */ |
136 | #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */ |
137 | #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */ |
138 | #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */ |
139 | #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */ |
140 | #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */ |
141 | #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */ |
142 | #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */ |
143 | #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */ |
144 | #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */ |
145 | #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */ |
146 | #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */ |
147 | #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */ |
148 | #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */ |
149 | #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */ |
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150 | |
151 | static const char *const ssh2_disconnect_reasons[] = { |
152 | NULL, |
153 | "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT", |
154 | "SSH_DISCONNECT_PROTOCOL_ERROR", |
155 | "SSH_DISCONNECT_KEY_EXCHANGE_FAILED", |
156 | "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED", |
157 | "SSH_DISCONNECT_MAC_ERROR", |
158 | "SSH_DISCONNECT_COMPRESSION_ERROR", |
159 | "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE", |
160 | "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED", |
161 | "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE", |
162 | "SSH_DISCONNECT_CONNECTION_LOST", |
163 | "SSH_DISCONNECT_BY_APPLICATION", |
164 | "SSH_DISCONNECT_TOO_MANY_CONNECTIONS", |
165 | "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER", |
166 | "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE", |
167 | "SSH_DISCONNECT_ILLEGAL_USER_NAME", |
168 | }; |
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169 | |
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170 | #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */ |
171 | #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */ |
172 | #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */ |
173 | #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */ |
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174 | |
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175 | #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */ |
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176 | |
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177 | /* |
178 | * Various remote-bug flags. |
179 | */ |
180 | #define BUG_CHOKES_ON_SSH1_IGNORE 1 |
181 | #define BUG_SSH2_HMAC 2 |
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182 | #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4 |
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183 | #define BUG_CHOKES_ON_RSA 8 |
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184 | #define BUG_SSH2_RSA_PADDING 16 |
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185 | |
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186 | static int ssh_pkt_ctx = 0; |
187 | |
188 | #define translate(x) if (type == x) return #x |
189 | #define translatec(x,ctx) if (type == x && (ssh_pkt_ctx & ctx)) return #x |
190 | char *ssh1_pkt_type(int type) |
191 | { |
192 | translate(SSH1_MSG_DISCONNECT); |
193 | translate(SSH1_SMSG_PUBLIC_KEY); |
194 | translate(SSH1_CMSG_SESSION_KEY); |
195 | translate(SSH1_CMSG_USER); |
196 | translate(SSH1_CMSG_AUTH_RSA); |
197 | translate(SSH1_SMSG_AUTH_RSA_CHALLENGE); |
198 | translate(SSH1_CMSG_AUTH_RSA_RESPONSE); |
199 | translate(SSH1_CMSG_AUTH_PASSWORD); |
200 | translate(SSH1_CMSG_REQUEST_PTY); |
201 | translate(SSH1_CMSG_WINDOW_SIZE); |
202 | translate(SSH1_CMSG_EXEC_SHELL); |
203 | translate(SSH1_CMSG_EXEC_CMD); |
204 | translate(SSH1_SMSG_SUCCESS); |
205 | translate(SSH1_SMSG_FAILURE); |
206 | translate(SSH1_CMSG_STDIN_DATA); |
207 | translate(SSH1_SMSG_STDOUT_DATA); |
208 | translate(SSH1_SMSG_STDERR_DATA); |
209 | translate(SSH1_CMSG_EOF); |
210 | translate(SSH1_SMSG_EXIT_STATUS); |
211 | translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION); |
212 | translate(SSH1_MSG_CHANNEL_OPEN_FAILURE); |
213 | translate(SSH1_MSG_CHANNEL_DATA); |
214 | translate(SSH1_MSG_CHANNEL_CLOSE); |
215 | translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION); |
216 | translate(SSH1_SMSG_X11_OPEN); |
217 | translate(SSH1_CMSG_PORT_FORWARD_REQUEST); |
218 | translate(SSH1_MSG_PORT_OPEN); |
219 | translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING); |
220 | translate(SSH1_SMSG_AGENT_OPEN); |
221 | translate(SSH1_MSG_IGNORE); |
222 | translate(SSH1_CMSG_EXIT_CONFIRMATION); |
223 | translate(SSH1_CMSG_X11_REQUEST_FORWARDING); |
224 | translate(SSH1_CMSG_AUTH_RHOSTS_RSA); |
225 | translate(SSH1_MSG_DEBUG); |
226 | translate(SSH1_CMSG_REQUEST_COMPRESSION); |
227 | translate(SSH1_CMSG_AUTH_TIS); |
228 | translate(SSH1_SMSG_AUTH_TIS_CHALLENGE); |
229 | translate(SSH1_CMSG_AUTH_TIS_RESPONSE); |
230 | translate(SSH1_CMSG_AUTH_CCARD); |
231 | translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE); |
232 | translate(SSH1_CMSG_AUTH_CCARD_RESPONSE); |
233 | return "unknown"; |
234 | } |
235 | char *ssh2_pkt_type(int type) |
236 | { |
237 | translate(SSH2_MSG_DISCONNECT); |
238 | translate(SSH2_MSG_IGNORE); |
239 | translate(SSH2_MSG_UNIMPLEMENTED); |
240 | translate(SSH2_MSG_DEBUG); |
241 | translate(SSH2_MSG_SERVICE_REQUEST); |
242 | translate(SSH2_MSG_SERVICE_ACCEPT); |
243 | translate(SSH2_MSG_KEXINIT); |
244 | translate(SSH2_MSG_NEWKEYS); |
245 | translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP1); |
246 | translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1); |
247 | translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX); |
248 | translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX); |
249 | translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX); |
250 | translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX); |
251 | translate(SSH2_MSG_USERAUTH_REQUEST); |
252 | translate(SSH2_MSG_USERAUTH_FAILURE); |
253 | translate(SSH2_MSG_USERAUTH_SUCCESS); |
254 | translate(SSH2_MSG_USERAUTH_BANNER); |
255 | translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY); |
256 | translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD); |
257 | translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER); |
258 | translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER); |
259 | translate(SSH2_MSG_GLOBAL_REQUEST); |
260 | translate(SSH2_MSG_REQUEST_SUCCESS); |
261 | translate(SSH2_MSG_REQUEST_FAILURE); |
262 | translate(SSH2_MSG_CHANNEL_OPEN); |
263 | translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); |
264 | translate(SSH2_MSG_CHANNEL_OPEN_FAILURE); |
265 | translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
266 | translate(SSH2_MSG_CHANNEL_DATA); |
267 | translate(SSH2_MSG_CHANNEL_EXTENDED_DATA); |
268 | translate(SSH2_MSG_CHANNEL_EOF); |
269 | translate(SSH2_MSG_CHANNEL_CLOSE); |
270 | translate(SSH2_MSG_CHANNEL_REQUEST); |
271 | translate(SSH2_MSG_CHANNEL_SUCCESS); |
272 | translate(SSH2_MSG_CHANNEL_FAILURE); |
273 | return "unknown"; |
274 | } |
275 | #undef translate |
276 | #undef translatec |
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277 | |
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278 | #define GET_32BIT(cp) \ |
279 | (((unsigned long)(unsigned char)(cp)[0] << 24) | \ |
280 | ((unsigned long)(unsigned char)(cp)[1] << 16) | \ |
281 | ((unsigned long)(unsigned char)(cp)[2] << 8) | \ |
282 | ((unsigned long)(unsigned char)(cp)[3])) |
283 | |
284 | #define PUT_32BIT(cp, value) { \ |
285 | (cp)[0] = (unsigned char)((value) >> 24); \ |
286 | (cp)[1] = (unsigned char)((value) >> 16); \ |
287 | (cp)[2] = (unsigned char)((value) >> 8); \ |
288 | (cp)[3] = (unsigned char)(value); } |
289 | |
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290 | enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM }; |
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291 | |
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292 | /* Coroutine mechanics for the sillier bits of the code */ |
293 | #define crBegin1 static int crLine = 0; |
294 | #define crBegin2 switch(crLine) { case 0:; |
295 | #define crBegin crBegin1; crBegin2; |
296 | #define crFinish(z) } crLine = 0; return (z) |
297 | #define crFinishV } crLine = 0; return |
298 | #define crReturn(z) \ |
299 | do {\ |
300 | crLine=__LINE__; return (z); case __LINE__:;\ |
301 | } while (0) |
302 | #define crReturnV \ |
303 | do {\ |
304 | crLine=__LINE__; return; case __LINE__:;\ |
305 | } while (0) |
306 | #define crStop(z) do{ crLine = 0; return (z); }while(0) |
307 | #define crStopV do{ crLine = 0; return; }while(0) |
fb09bf1c |
308 | #define crWaitUntil(c) do { crReturn(0); } while (!(c)) |
7cca0d81 |
309 | #define crWaitUntilV(c) do { crReturnV; } while (!(c)) |
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310 | |
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311 | extern char *x11_init(Socket *, char *, void *); |
312 | extern void x11_close(Socket); |
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313 | extern int x11_send(Socket, char *, int); |
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314 | extern void x11_invent_auth(char *, int, char *, int); |
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315 | extern void x11_unthrottle(Socket s); |
316 | extern void x11_override_throttle(Socket s, int enable); |
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317 | |
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318 | extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c); |
319 | extern char *pfd_addforward(char *desthost, int destport, int port); |
320 | extern void pfd_close(Socket s); |
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321 | extern int pfd_send(Socket s, char *data, int len); |
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322 | extern void pfd_confirm(Socket s); |
5471d09a |
323 | extern void pfd_unthrottle(Socket s); |
324 | extern void pfd_override_throttle(Socket s, int enable); |
325 | |
3d63ca2e |
326 | static void ssh2_pkt_init(int pkt_type); |
327 | static void ssh2_pkt_addbool(unsigned char value); |
328 | static void ssh2_pkt_adduint32(unsigned long value); |
329 | static void ssh2_pkt_addstring_start(void); |
330 | static void ssh2_pkt_addstring_str(char *data); |
331 | static void ssh2_pkt_addstring_data(char *data, int len); |
332 | static void ssh2_pkt_addstring(char *data); |
333 | static char *ssh2_mpint_fmt(Bignum b, int *len); |
334 | static void ssh2_pkt_addmp(Bignum b); |
335 | static int ssh2_pkt_construct(void); |
336 | static void ssh2_pkt_send(void); |
337 | |
5471d09a |
338 | /* |
339 | * Buffer management constants. There are several of these for |
340 | * various different purposes: |
341 | * |
342 | * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up |
343 | * on a local data stream before we throttle the whole SSH |
344 | * connection (in SSH1 only). Throttling the whole connection is |
345 | * pretty drastic so we set this high in the hope it won't |
346 | * happen very often. |
347 | * |
348 | * - SSH_MAX_BACKLOG is the amount of backlog that must build up |
349 | * on the SSH connection itself before we defensively throttle |
350 | * _all_ local data streams. This is pretty drastic too (though |
351 | * thankfully unlikely in SSH2 since the window mechanism should |
352 | * ensure that the server never has any need to throttle its end |
353 | * of the connection), so we set this high as well. |
354 | * |
355 | * - OUR_V2_WINSIZE is the maximum window size we present on SSH2 |
356 | * channels. |
357 | */ |
358 | |
359 | #define SSH1_BUFFER_LIMIT 32768 |
360 | #define SSH_MAX_BACKLOG 32768 |
361 | #define OUR_V2_WINSIZE 16384 |
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362 | |
a92dd380 |
363 | const static struct ssh_kex *kex_algs[] = { |
a92dd380 |
364 | &ssh_diffiehellman_gex, |
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365 | &ssh_diffiehellman |
366 | }; |
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367 | |
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368 | const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss }; |
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369 | |
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370 | static void nullmac_key(unsigned char *key) |
371 | { |
372 | } |
373 | static void nullmac_generate(unsigned char *blk, int len, |
374 | unsigned long seq) |
375 | { |
376 | } |
377 | static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) |
378 | { |
379 | return 1; |
380 | } |
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381 | const static struct ssh_mac ssh_mac_none = { |
d39f364a |
382 | nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0 |
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383 | }; |
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384 | const static struct ssh_mac *macs[] = { |
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385 | &ssh_sha1, &ssh_md5, &ssh_mac_none |
386 | }; |
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387 | const static struct ssh_mac *buggymacs[] = { |
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388 | &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none |
389 | }; |
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390 | |
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391 | static void ssh_comp_none_init(void) |
392 | { |
393 | } |
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394 | static int ssh_comp_none_block(unsigned char *block, int len, |
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395 | unsigned char **outblock, int *outlen) |
396 | { |
397 | return 0; |
398 | } |
399 | static int ssh_comp_none_disable(void) |
400 | { |
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401 | return 0; |
402 | } |
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403 | const static struct ssh_compress ssh_comp_none = { |
4ba9b64b |
404 | "none", |
405 | ssh_comp_none_init, ssh_comp_none_block, |
63b00c83 |
406 | ssh_comp_none_init, ssh_comp_none_block, |
407 | ssh_comp_none_disable |
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408 | }; |
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409 | extern const struct ssh_compress ssh_zlib; |
410 | const static struct ssh_compress *compressions[] = { |
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411 | &ssh_zlib, &ssh_comp_none |
412 | }; |
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413 | |
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414 | enum { /* channel types */ |
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415 | CHAN_MAINSESSION, |
416 | CHAN_X11, |
417 | CHAN_AGENT, |
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418 | CHAN_SOCKDATA, |
419 | CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */ |
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420 | }; |
421 | |
dacbd0e8 |
422 | /* |
423 | * 2-3-4 tree storing channels. |
424 | */ |
425 | struct ssh_channel { |
d211621f |
426 | unsigned remoteid, localid; |
dacbd0e8 |
427 | int type; |
428 | int closes; |
5471d09a |
429 | union { |
430 | struct ssh1_data_channel { |
431 | int throttling; |
432 | } v1; |
433 | struct ssh2_data_channel { |
434 | bufchain outbuffer; |
435 | unsigned remwindow, remmaxpkt; |
436 | unsigned locwindow; |
437 | } v2; |
438 | } v; |
dacbd0e8 |
439 | union { |
32874aea |
440 | struct ssh_agent_channel { |
441 | unsigned char *message; |
442 | unsigned char msglen[4]; |
443 | int lensofar, totallen; |
444 | } a; |
445 | struct ssh_x11_channel { |
446 | Socket s; |
447 | } x11; |
d74d141c |
448 | struct ssh_pfd_channel { |
449 | Socket s; |
450 | } pfd; |
dacbd0e8 |
451 | } u; |
452 | }; |
57476f6b |
453 | |
d74d141c |
454 | /* |
bc240b21 |
455 | * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH |
456 | * 2 use this structure in different ways, reflecting SSH 2's |
457 | * altogether saner approach to port forwarding. |
458 | * |
459 | * In SSH 1, you arrange a remote forwarding by sending the server |
460 | * the remote port number, and the local destination host:port. |
461 | * When a connection comes in, the server sends you back that |
462 | * host:port pair, and you connect to it. This is a ready-made |
463 | * security hole if you're not on the ball: a malicious server |
464 | * could send you back _any_ host:port pair, so if you trustingly |
465 | * connect to the address it gives you then you've just opened the |
466 | * entire inside of your corporate network just by connecting |
467 | * through it to a dodgy SSH server. Hence, we must store a list of |
468 | * host:port pairs we _are_ trying to forward to, and reject a |
469 | * connection request from the server if it's not in the list. |
470 | * |
471 | * In SSH 2, each side of the connection minds its own business and |
472 | * doesn't send unnecessary information to the other. You arrange a |
473 | * remote forwarding by sending the server just the remote port |
474 | * number. When a connection comes in, the server tells you which |
475 | * of its ports was connected to; and _you_ have to remember what |
476 | * local host:port pair went with that port number. |
477 | * |
478 | * Hence: in SSH 1 this structure stores host:port pairs we intend |
479 | * to allow connections to, and is indexed by those host:port |
480 | * pairs. In SSH 2 it stores a mapping from source port to |
481 | * destination host:port pair, and is indexed by source port. |
d74d141c |
482 | */ |
483 | struct ssh_rportfwd { |
bc240b21 |
484 | unsigned sport, dport; |
485 | char dhost[256]; |
d74d141c |
486 | }; |
487 | |
57476f6b |
488 | struct Packet { |
489 | long length; |
490 | int type; |
491 | unsigned char *data; |
492 | unsigned char *body; |
493 | long savedpos; |
494 | long maxlen; |
495 | }; |
496 | |
0db56f73 |
497 | static SHA_State exhash, exhashbase; |
57476f6b |
498 | |
8df7a775 |
499 | static Socket s = NULL; |
57476f6b |
500 | |
501 | static unsigned char session_key[32]; |
4ba9b64b |
502 | static int ssh1_compressing; |
b96dc54c |
503 | static int ssh1_remote_protoflags; |
504 | static int ssh1_local_protoflags; |
db7d555c |
505 | static int ssh_agentfwd_enabled; |
9c964e85 |
506 | static int ssh_X11_fwd_enabled; |
7d503c31 |
507 | static int ssh_remote_bugs; |
57476f6b |
508 | static const struct ssh_cipher *cipher = NULL; |
0a3f1d48 |
509 | static const struct ssh2_cipher *cscipher = NULL; |
510 | static const struct ssh2_cipher *sccipher = NULL; |
57476f6b |
511 | static const struct ssh_mac *csmac = NULL; |
512 | static const struct ssh_mac *scmac = NULL; |
513 | static const struct ssh_compress *cscomp = NULL; |
514 | static const struct ssh_compress *sccomp = NULL; |
515 | static const struct ssh_kex *kex = NULL; |
e055a386 |
516 | static const struct ssh_signkey *hostkey = NULL; |
65a22376 |
517 | static unsigned char ssh2_session_id[20]; |
57476f6b |
518 | |
519 | static char *savedhost; |
520 | static int savedport; |
521 | static int ssh_send_ok; |
0965bee0 |
522 | static int ssh_echoing, ssh_editing; |
57476f6b |
523 | |
32874aea |
524 | static tree234 *ssh_channels; /* indexed by local id */ |
57476f6b |
525 | static struct ssh_channel *mainchan; /* primary session channel */ |
d8d6c7e5 |
526 | static int ssh_exitcode = -1; |
57476f6b |
527 | |
d74d141c |
528 | static tree234 *ssh_rportfwds; |
529 | |
57476f6b |
530 | static enum { |
3687d221 |
531 | SSH_STATE_PREPACKET, |
57476f6b |
532 | SSH_STATE_BEFORE_SIZE, |
533 | SSH_STATE_INTERMED, |
534 | SSH_STATE_SESSION, |
535 | SSH_STATE_CLOSED |
3687d221 |
536 | } ssh_state = SSH_STATE_PREPACKET; |
57476f6b |
537 | |
3687d221 |
538 | static int size_needed = FALSE, eof_needed = FALSE; |
57476f6b |
539 | |
540 | static struct Packet pktin = { 0, 0, NULL, NULL, 0 }; |
541 | static struct Packet pktout = { 0, 0, NULL, NULL, 0 }; |
b185170a |
542 | static unsigned char *deferred_send_data = NULL; |
543 | static int deferred_len = 0, deferred_size = 0; |
57476f6b |
544 | |
fd5e5847 |
545 | /* |
546 | * Gross hack: pscp will try to start SFTP but fall back to scp1 if |
547 | * that fails. This variable is the means by which scp.c can reach |
548 | * into the SSH code and find out which one it got. |
549 | */ |
550 | int ssh_fallback_cmd = 0; |
551 | |
57476f6b |
552 | static int ssh_version; |
5471d09a |
553 | static int ssh1_throttle_count; |
554 | static int ssh_overall_bufsize; |
555 | static int ssh_throttled_all; |
556 | static int ssh1_stdout_throttling; |
32874aea |
557 | static void (*ssh_protocol) (unsigned char *in, int inlen, int ispkt); |
57476f6b |
558 | static void ssh1_protocol(unsigned char *in, int inlen, int ispkt); |
559 | static void ssh2_protocol(unsigned char *in, int inlen, int ispkt); |
560 | static void ssh_size(void); |
32874aea |
561 | static void ssh_special(Telnet_Special); |
5471d09a |
562 | static int ssh2_try_send(struct ssh_channel *c); |
32874aea |
563 | static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, |
564 | int len); |
5471d09a |
565 | static void ssh_throttle_all(int enable, int bufsize); |
566 | static void ssh2_set_window(struct ssh_channel *c, unsigned newwin); |
32874aea |
567 | static int (*s_rdpkt) (unsigned char **data, int *datalen); |
5471d09a |
568 | static int ssh_sendbuffer(void); |
57476f6b |
569 | |
570 | static struct rdpkt1_state_tag { |
571 | long len, pad, biglen, to_read; |
572 | unsigned long realcrc, gotcrc; |
573 | unsigned char *p; |
574 | int i; |
575 | int chunk; |
576 | } rdpkt1_state; |
577 | |
960e736a |
578 | static struct rdpkt2_state_tag { |
579 | long len, pad, payload, packetlen, maclen; |
580 | int i; |
581 | int cipherblk; |
582 | unsigned long incoming_sequence; |
583 | } rdpkt2_state; |
584 | |
32874aea |
585 | static int ssh_channelcmp(void *av, void *bv) |
586 | { |
587 | struct ssh_channel *a = (struct ssh_channel *) av; |
588 | struct ssh_channel *b = (struct ssh_channel *) bv; |
589 | if (a->localid < b->localid) |
590 | return -1; |
591 | if (a->localid > b->localid) |
592 | return +1; |
dacbd0e8 |
593 | return 0; |
594 | } |
32874aea |
595 | static int ssh_channelfind(void *av, void *bv) |
596 | { |
597 | unsigned *a = (unsigned *) av; |
598 | struct ssh_channel *b = (struct ssh_channel *) bv; |
599 | if (*a < b->localid) |
600 | return -1; |
601 | if (*a > b->localid) |
602 | return +1; |
dacbd0e8 |
603 | return 0; |
604 | } |
605 | |
bc240b21 |
606 | static int ssh_rportcmp_ssh1(void *av, void *bv) |
d74d141c |
607 | { |
608 | struct ssh_rportfwd *a = (struct ssh_rportfwd *) av; |
609 | struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv; |
610 | int i; |
bc240b21 |
611 | if ( (i = strcmp(a->dhost, b->dhost)) != 0) |
d74d141c |
612 | return i < 0 ? -1 : +1; |
bc240b21 |
613 | if (a->dport > b->dport) |
614 | return +1; |
615 | if (a->dport < b->dport) |
616 | return -1; |
617 | return 0; |
618 | } |
619 | |
620 | static int ssh_rportcmp_ssh2(void *av, void *bv) |
621 | { |
622 | struct ssh_rportfwd *a = (struct ssh_rportfwd *) av; |
623 | struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv; |
cdcbdf3b |
624 | |
bc240b21 |
625 | if (a->sport > b->sport) |
d74d141c |
626 | return +1; |
bc240b21 |
627 | if (a->sport < b->sport) |
628 | return -1; |
d74d141c |
629 | return 0; |
630 | } |
631 | |
32874aea |
632 | static int alloc_channel_id(void) |
633 | { |
260f3dec |
634 | const unsigned CHANNEL_NUMBER_OFFSET = 256; |
635 | unsigned low, high, mid; |
d2371c81 |
636 | int tsize; |
637 | struct ssh_channel *c; |
638 | |
639 | /* |
640 | * First-fit allocation of channel numbers: always pick the |
641 | * lowest unused one. To do this, binary-search using the |
642 | * counted B-tree to find the largest channel ID which is in a |
643 | * contiguous sequence from the beginning. (Precisely |
644 | * everything in that sequence must have ID equal to its tree |
645 | * index plus CHANNEL_NUMBER_OFFSET.) |
646 | */ |
647 | tsize = count234(ssh_channels); |
648 | |
32874aea |
649 | low = -1; |
650 | high = tsize; |
d2371c81 |
651 | while (high - low > 1) { |
652 | mid = (high + low) / 2; |
653 | c = index234(ssh_channels, mid); |
654 | if (c->localid == mid + CHANNEL_NUMBER_OFFSET) |
655 | low = mid; /* this one is fine */ |
656 | else |
657 | high = mid; /* this one is past it */ |
658 | } |
659 | /* |
660 | * Now low points to either -1, or the tree index of the |
661 | * largest ID in the initial sequence. |
662 | */ |
663 | { |
664 | unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET; |
665 | assert(NULL == find234(ssh_channels, &i, ssh_channelfind)); |
666 | } |
667 | return low + 1 + CHANNEL_NUMBER_OFFSET; |
668 | } |
669 | |
32874aea |
670 | static void c_write(char *buf, int len) |
671 | { |
67779be7 |
672 | if ((flags & FLAG_STDERR)) { |
32874aea |
673 | int i; |
674 | for (i = 0; i < len; i++) |
675 | if (buf[i] != '\r') |
676 | fputc(buf[i], stderr); |
fb09bf1c |
677 | return; |
678 | } |
fe50e814 |
679 | from_backend(1, buf, len); |
3bdaf79d |
680 | } |
681 | |
32874aea |
682 | static void c_write_untrusted(char *buf, int len) |
683 | { |
a209e957 |
684 | int i; |
685 | for (i = 0; i < len; i++) { |
32874aea |
686 | if (buf[i] == '\n') |
687 | c_write("\r\n", 2); |
688 | else if ((buf[i] & 0x60) || (buf[i] == '\r')) |
689 | c_write(buf + i, 1); |
a209e957 |
690 | } |
691 | } |
692 | |
32874aea |
693 | static void c_write_str(char *buf) |
694 | { |
1408a877 |
695 | c_write(buf, strlen(buf)); |
696 | } |
697 | |
fb09bf1c |
698 | /* |
699 | * Collect incoming data in the incoming packet buffer. |
e5574168 |
700 | * Decipher and verify the packet when it is completely read. |
701 | * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets. |
fb09bf1c |
702 | * Update the *data and *datalen variables. |
703 | * Return the additional nr of bytes needed, or 0 when |
704 | * a complete packet is available. |
705 | */ |
e5574168 |
706 | static int ssh1_rdpkt(unsigned char **data, int *datalen) |
fb09bf1c |
707 | { |
57476f6b |
708 | struct rdpkt1_state_tag *st = &rdpkt1_state; |
374330e2 |
709 | |
710 | crBegin; |
374330e2 |
711 | |
32874aea |
712 | next_packet: |
37508af4 |
713 | |
fb09bf1c |
714 | pktin.type = 0; |
715 | pktin.length = 0; |
374330e2 |
716 | |
57476f6b |
717 | for (st->i = st->len = 0; st->i < 4; st->i++) { |
fb09bf1c |
718 | while ((*datalen) == 0) |
32874aea |
719 | crReturn(4 - st->i); |
57476f6b |
720 | st->len = (st->len << 8) + **data; |
fb09bf1c |
721 | (*data)++, (*datalen)--; |
722 | } |
374330e2 |
723 | |
57476f6b |
724 | st->pad = 8 - (st->len % 8); |
725 | st->biglen = st->len + st->pad; |
726 | pktin.length = st->len - 5; |
fb09bf1c |
727 | |
57476f6b |
728 | if (pktin.maxlen < st->biglen) { |
729 | pktin.maxlen = st->biglen; |
32874aea |
730 | pktin.data = (pktin.data == NULL ? smalloc(st->biglen + APIEXTRA) : |
731 | srealloc(pktin.data, st->biglen + APIEXTRA)); |
fb09bf1c |
732 | if (!pktin.data) |
733 | fatalbox("Out of memory"); |
734 | } |
374330e2 |
735 | |
57476f6b |
736 | st->to_read = st->biglen; |
737 | st->p = pktin.data; |
738 | while (st->to_read > 0) { |
32874aea |
739 | st->chunk = st->to_read; |
fb09bf1c |
740 | while ((*datalen) == 0) |
57476f6b |
741 | crReturn(st->to_read); |
742 | if (st->chunk > (*datalen)) |
743 | st->chunk = (*datalen); |
744 | memcpy(st->p, *data, st->chunk); |
745 | *data += st->chunk; |
746 | *datalen -= st->chunk; |
747 | st->p += st->chunk; |
748 | st->to_read -= st->chunk; |
fb09bf1c |
749 | } |
374330e2 |
750 | |
9a3a93a5 |
751 | if (cipher && detect_attack(pktin.data, st->biglen, NULL)) { |
752 | bombout(("Network attack (CRC compensation) detected!")); |
753 | crReturn(0); |
754 | } |
755 | |
fb09bf1c |
756 | if (cipher) |
57476f6b |
757 | cipher->decrypt(pktin.data, st->biglen); |
374330e2 |
758 | |
32874aea |
759 | st->realcrc = crc32(pktin.data, st->biglen - 4); |
760 | st->gotcrc = GET_32BIT(pktin.data + st->biglen - 4); |
57476f6b |
761 | if (st->gotcrc != st->realcrc) { |
8d5de777 |
762 | bombout(("Incorrect CRC received on packet")); |
32874aea |
763 | crReturn(0); |
fb09bf1c |
764 | } |
572f871e |
765 | |
4ba9b64b |
766 | pktin.body = pktin.data + st->pad + 1; |
767 | |
768 | if (ssh1_compressing) { |
769 | unsigned char *decompblk; |
770 | int decomplen; |
32874aea |
771 | zlib_decompress_block(pktin.body - 1, pktin.length + 1, |
4ba9b64b |
772 | &decompblk, &decomplen); |
773 | |
774 | if (pktin.maxlen < st->pad + decomplen) { |
775 | pktin.maxlen = st->pad + decomplen; |
32874aea |
776 | pktin.data = srealloc(pktin.data, pktin.maxlen + APIEXTRA); |
777 | pktin.body = pktin.data + st->pad + 1; |
4ba9b64b |
778 | if (!pktin.data) |
779 | fatalbox("Out of memory"); |
780 | } |
781 | |
32874aea |
782 | memcpy(pktin.body - 1, decompblk, decomplen); |
dcbde236 |
783 | sfree(decompblk); |
32874aea |
784 | pktin.length = decomplen - 1; |
4ba9b64b |
785 | } |
786 | |
00db133f |
787 | pktin.type = pktin.body[-1]; |
788 | |
789 | log_packet(PKT_INCOMING, pktin.type, ssh1_pkt_type(pktin.type), |
790 | pktin.body, pktin.length); |
791 | |
e5574168 |
792 | if (pktin.type == SSH1_SMSG_STDOUT_DATA || |
32874aea |
793 | pktin.type == SSH1_SMSG_STDERR_DATA || |
794 | pktin.type == SSH1_MSG_DEBUG || |
795 | pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE || |
796 | pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) { |
3d63ca2e |
797 | long stringlen = GET_32BIT(pktin.body); |
798 | if (stringlen + 4 != pktin.length) { |
8d5de777 |
799 | bombout(("Received data packet with bogus string length")); |
32874aea |
800 | crReturn(0); |
801 | } |
fb09bf1c |
802 | } |
803 | |
e5574168 |
804 | if (pktin.type == SSH1_MSG_DEBUG) { |
fb09bf1c |
805 | /* log debug message */ |
806 | char buf[80]; |
3d63ca2e |
807 | int stringlen = GET_32BIT(pktin.body); |
fb09bf1c |
808 | strcpy(buf, "Remote: "); |
3d63ca2e |
809 | if (stringlen > 70) |
810 | stringlen = 70; |
811 | memcpy(buf + 8, pktin.body + 4, stringlen); |
812 | buf[8 + stringlen] = '\0'; |
fb09bf1c |
813 | logevent(buf); |
814 | goto next_packet; |
e5574168 |
815 | } else if (pktin.type == SSH1_MSG_IGNORE) { |
fb09bf1c |
816 | /* do nothing */ |
817 | goto next_packet; |
818 | } |
819 | |
38c4a8da |
820 | if (pktin.type == SSH1_MSG_DISCONNECT) { |
821 | /* log reason code in disconnect message */ |
822 | char buf[256]; |
260f3dec |
823 | unsigned msglen = GET_32BIT(pktin.body); |
824 | unsigned nowlen; |
38c4a8da |
825 | strcpy(buf, "Remote sent disconnect: "); |
826 | nowlen = strlen(buf); |
32874aea |
827 | if (msglen > sizeof(buf) - nowlen - 1) |
828 | msglen = sizeof(buf) - nowlen - 1; |
829 | memcpy(buf + nowlen, pktin.body + 4, msglen); |
830 | buf[nowlen + msglen] = '\0'; |
247308b5 |
831 | /* logevent(buf); (this is now done within the bombout macro) */ |
4eb195cc |
832 | bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen)); |
e14d0f19 |
833 | crReturn(0); |
38c4a8da |
834 | } |
835 | |
fb09bf1c |
836 | crFinish(0); |
837 | } |
838 | |
e5574168 |
839 | static int ssh2_rdpkt(unsigned char **data, int *datalen) |
840 | { |
960e736a |
841 | struct rdpkt2_state_tag *st = &rdpkt2_state; |
e5574168 |
842 | |
843 | crBegin; |
844 | |
32874aea |
845 | next_packet: |
e5574168 |
846 | pktin.type = 0; |
847 | pktin.length = 0; |
960e736a |
848 | if (sccipher) |
32874aea |
849 | st->cipherblk = sccipher->blksize; |
e5574168 |
850 | else |
32874aea |
851 | st->cipherblk = 8; |
960e736a |
852 | if (st->cipherblk < 8) |
32874aea |
853 | st->cipherblk = 8; |
960e736a |
854 | |
855 | if (pktin.maxlen < st->cipherblk) { |
856 | pktin.maxlen = st->cipherblk; |
32874aea |
857 | pktin.data = |
858 | (pktin.data == |
859 | NULL ? smalloc(st->cipherblk + |
860 | APIEXTRA) : srealloc(pktin.data, |
861 | st->cipherblk + |
862 | APIEXTRA)); |
e5574168 |
863 | if (!pktin.data) |
864 | fatalbox("Out of memory"); |
865 | } |
866 | |
867 | /* |
868 | * Acquire and decrypt the first block of the packet. This will |
869 | * contain the length and padding details. |
870 | */ |
32874aea |
871 | for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) { |
e5574168 |
872 | while ((*datalen) == 0) |
32874aea |
873 | crReturn(st->cipherblk - st->i); |
960e736a |
874 | pktin.data[st->i] = *(*data)++; |
32874aea |
875 | (*datalen)--; |
e5574168 |
876 | } |
4252c9cc |
877 | |
e5574168 |
878 | if (sccipher) |
32874aea |
879 | sccipher->decrypt(pktin.data, st->cipherblk); |
e5574168 |
880 | |
881 | /* |
882 | * Now get the length and padding figures. |
883 | */ |
960e736a |
884 | st->len = GET_32BIT(pktin.data); |
885 | st->pad = pktin.data[4]; |
e5574168 |
886 | |
887 | /* |
888 | * This enables us to deduce the payload length. |
889 | */ |
960e736a |
890 | st->payload = st->len - st->pad - 1; |
e5574168 |
891 | |
960e736a |
892 | pktin.length = st->payload + 5; |
e5574168 |
893 | |
894 | /* |
895 | * So now we can work out the total packet length. |
896 | */ |
960e736a |
897 | st->packetlen = st->len + 4; |
898 | st->maclen = scmac ? scmac->len : 0; |
e5574168 |
899 | |
900 | /* |
901 | * Adjust memory allocation if packet is too big. |
902 | */ |
32874aea |
903 | if (pktin.maxlen < st->packetlen + st->maclen) { |
904 | pktin.maxlen = st->packetlen + st->maclen; |
905 | pktin.data = |
906 | (pktin.data == |
907 | NULL ? smalloc(pktin.maxlen + APIEXTRA) : srealloc(pktin.data, |
908 | pktin.maxlen |
909 | + |
910 | APIEXTRA)); |
e5574168 |
911 | if (!pktin.data) |
912 | fatalbox("Out of memory"); |
913 | } |
914 | |
915 | /* |
916 | * Read and decrypt the remainder of the packet. |
917 | */ |
32874aea |
918 | for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; |
919 | st->i++) { |
e5574168 |
920 | while ((*datalen) == 0) |
960e736a |
921 | crReturn(st->packetlen + st->maclen - st->i); |
922 | pktin.data[st->i] = *(*data)++; |
32874aea |
923 | (*datalen)--; |
e5574168 |
924 | } |
925 | /* Decrypt everything _except_ the MAC. */ |
926 | if (sccipher) |
32874aea |
927 | sccipher->decrypt(pktin.data + st->cipherblk, |
928 | st->packetlen - st->cipherblk); |
e5574168 |
929 | |
930 | /* |
931 | * Check the MAC. |
932 | */ |
32874aea |
933 | if (scmac |
934 | && !scmac->verify(pktin.data, st->len + 4, |
935 | st->incoming_sequence)) { |
8d5de777 |
936 | bombout(("Incorrect MAC received on packet")); |
32874aea |
937 | crReturn(0); |
8d5de777 |
938 | } |
32874aea |
939 | st->incoming_sequence++; /* whether or not we MACed */ |
e5574168 |
940 | |
4ba9b64b |
941 | /* |
942 | * Decompress packet payload. |
943 | */ |
944 | { |
945 | unsigned char *newpayload; |
946 | int newlen; |
32874aea |
947 | if (sccomp && sccomp->decompress(pktin.data + 5, pktin.length - 5, |
4ba9b64b |
948 | &newpayload, &newlen)) { |
32874aea |
949 | if (pktin.maxlen < newlen + 5) { |
950 | pktin.maxlen = newlen + 5; |
951 | pktin.data = |
952 | (pktin.data == |
953 | NULL ? smalloc(pktin.maxlen + |
954 | APIEXTRA) : srealloc(pktin.data, |
955 | pktin.maxlen + |
956 | APIEXTRA)); |
4ba9b64b |
957 | if (!pktin.data) |
958 | fatalbox("Out of memory"); |
959 | } |
960 | pktin.length = 5 + newlen; |
32874aea |
961 | memcpy(pktin.data + 5, newpayload, newlen); |
dcbde236 |
962 | sfree(newpayload); |
4ba9b64b |
963 | } |
964 | } |
965 | |
e5574168 |
966 | pktin.savedpos = 6; |
967 | pktin.type = pktin.data[5]; |
e5574168 |
968 | |
00db133f |
969 | log_packet(PKT_INCOMING, pktin.type, ssh2_pkt_type(pktin.type), |
970 | pktin.data+6, pktin.length-6); |
971 | |
3d63ca2e |
972 | switch (pktin.type) { |
973 | /* |
974 | * These packets we must handle instantly. |
975 | */ |
976 | case SSH2_MSG_DISCONNECT: |
977 | { |
978 | /* log reason code in disconnect message */ |
979 | char buf[256]; |
980 | int reason = GET_32BIT(pktin.data + 6); |
981 | unsigned msglen = GET_32BIT(pktin.data + 10); |
982 | unsigned nowlen; |
983 | if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) { |
984 | sprintf(buf, "Received disconnect message (%s)", |
985 | ssh2_disconnect_reasons[reason]); |
986 | } else { |
987 | sprintf(buf, "Received disconnect message (unknown type %d)", |
988 | reason); |
989 | } |
990 | logevent(buf); |
991 | strcpy(buf, "Disconnection message text: "); |
992 | nowlen = strlen(buf); |
993 | if (msglen > sizeof(buf) - nowlen - 1) |
994 | msglen = sizeof(buf) - nowlen - 1; |
995 | memcpy(buf + nowlen, pktin.data + 14, msglen); |
996 | buf[nowlen + msglen] = '\0'; |
997 | logevent(buf); |
998 | bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"", |
999 | reason, |
1000 | (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ? |
1001 | ssh2_disconnect_reasons[reason] : "unknown", |
1002 | buf+nowlen)); |
1003 | crReturn(0); |
1004 | } |
1005 | break; |
1006 | case SSH2_MSG_IGNORE: |
1007 | goto next_packet; |
1008 | case SSH2_MSG_DEBUG: |
1009 | { |
1010 | /* log the debug message */ |
1011 | char buf[512]; |
1012 | /* int display = pktin.body[6]; */ |
1013 | int stringlen = GET_32BIT(pktin.data+7); |
1014 | int prefix; |
1015 | strcpy(buf, "Remote debug message: "); |
1016 | prefix = strlen(buf); |
1017 | if (stringlen > sizeof(buf)-prefix-1) |
1018 | stringlen = sizeof(buf)-prefix-1; |
1019 | memcpy(buf + prefix, pktin.data + 11, stringlen); |
1020 | buf[prefix + stringlen] = '\0'; |
1021 | logevent(buf); |
38c4a8da |
1022 | } |
3d63ca2e |
1023 | goto next_packet; /* FIXME: print the debug message */ |
1024 | |
1025 | /* |
1026 | * These packets we need do nothing about here. |
1027 | */ |
1028 | case SSH2_MSG_UNIMPLEMENTED: |
1029 | case SSH2_MSG_SERVICE_REQUEST: |
1030 | case SSH2_MSG_SERVICE_ACCEPT: |
1031 | case SSH2_MSG_KEXINIT: |
1032 | case SSH2_MSG_NEWKEYS: |
1033 | case SSH2_MSG_KEXDH_INIT: |
1034 | case SSH2_MSG_KEXDH_REPLY: |
1035 | /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */ |
1036 | /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */ |
1037 | case SSH2_MSG_KEX_DH_GEX_INIT: |
1038 | case SSH2_MSG_KEX_DH_GEX_REPLY: |
1039 | case SSH2_MSG_USERAUTH_REQUEST: |
1040 | case SSH2_MSG_USERAUTH_FAILURE: |
1041 | case SSH2_MSG_USERAUTH_SUCCESS: |
1042 | case SSH2_MSG_USERAUTH_BANNER: |
1043 | case SSH2_MSG_USERAUTH_PK_OK: |
1044 | /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */ |
1045 | /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */ |
1046 | case SSH2_MSG_USERAUTH_INFO_RESPONSE: |
1047 | case SSH2_MSG_GLOBAL_REQUEST: |
1048 | case SSH2_MSG_REQUEST_SUCCESS: |
1049 | case SSH2_MSG_REQUEST_FAILURE: |
1050 | case SSH2_MSG_CHANNEL_OPEN: |
1051 | case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION: |
1052 | case SSH2_MSG_CHANNEL_OPEN_FAILURE: |
1053 | case SSH2_MSG_CHANNEL_WINDOW_ADJUST: |
1054 | case SSH2_MSG_CHANNEL_DATA: |
1055 | case SSH2_MSG_CHANNEL_EXTENDED_DATA: |
1056 | case SSH2_MSG_CHANNEL_EOF: |
1057 | case SSH2_MSG_CHANNEL_CLOSE: |
1058 | case SSH2_MSG_CHANNEL_REQUEST: |
1059 | case SSH2_MSG_CHANNEL_SUCCESS: |
1060 | case SSH2_MSG_CHANNEL_FAILURE: |
1061 | break; |
1062 | |
1063 | /* |
1064 | * For anything else we send SSH2_MSG_UNIMPLEMENTED. |
1065 | */ |
1066 | default: |
1067 | ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED); |
1068 | ssh2_pkt_adduint32(st->incoming_sequence - 1); |
1069 | ssh2_pkt_send(); |
1070 | break; |
38c4a8da |
1071 | } |
1072 | |
e5574168 |
1073 | crFinish(0); |
1074 | } |
1075 | |
32874aea |
1076 | static void ssh1_pktout_size(int len) |
1077 | { |
374330e2 |
1078 | int pad, biglen; |
1079 | |
1080 | len += 5; /* type and CRC */ |
32874aea |
1081 | pad = 8 - (len % 8); |
374330e2 |
1082 | biglen = len + pad; |
1083 | |
32874aea |
1084 | pktout.length = len - 5; |
374330e2 |
1085 | if (pktout.maxlen < biglen) { |
1086 | pktout.maxlen = biglen; |
8f203108 |
1087 | #ifdef MSCRYPTOAPI |
fb09bf1c |
1088 | /* Allocate enough buffer space for extra block |
8f203108 |
1089 | * for MS CryptEncrypt() */ |
32874aea |
1090 | pktout.data = (pktout.data == NULL ? smalloc(biglen + 12) : |
1091 | srealloc(pktout.data, biglen + 12)); |
8f203108 |
1092 | #else |
32874aea |
1093 | pktout.data = (pktout.data == NULL ? smalloc(biglen + 4) : |
1094 | srealloc(pktout.data, biglen + 4)); |
8f203108 |
1095 | #endif |
374330e2 |
1096 | if (!pktout.data) |
1097 | fatalbox("Out of memory"); |
1098 | } |
32874aea |
1099 | pktout.body = pktout.data + 4 + pad + 1; |
4ba9b64b |
1100 | } |
374330e2 |
1101 | |
32874aea |
1102 | static void s_wrpkt_start(int type, int len) |
1103 | { |
4ba9b64b |
1104 | ssh1_pktout_size(len); |
374330e2 |
1105 | pktout.type = type; |
374330e2 |
1106 | } |
1107 | |
32874aea |
1108 | static int s_wrpkt_prepare(void) |
1109 | { |
374330e2 |
1110 | int pad, len, biglen, i; |
1111 | unsigned long crc; |
1112 | |
4ba9b64b |
1113 | pktout.body[-1] = pktout.type; |
1114 | |
00db133f |
1115 | log_packet(PKT_OUTGOING, pktout.type, ssh1_pkt_type(pktout.type), |
1116 | pktout.body, pktout.length); |
1117 | |
4ba9b64b |
1118 | if (ssh1_compressing) { |
1119 | unsigned char *compblk; |
1120 | int complen; |
32874aea |
1121 | zlib_compress_block(pktout.body - 1, pktout.length + 1, |
4ba9b64b |
1122 | &compblk, &complen); |
32874aea |
1123 | ssh1_pktout_size(complen - 1); |
1124 | memcpy(pktout.body - 1, compblk, complen); |
dcbde236 |
1125 | sfree(compblk); |
4ba9b64b |
1126 | } |
1127 | |
374330e2 |
1128 | len = pktout.length + 5; /* type and CRC */ |
32874aea |
1129 | pad = 8 - (len % 8); |
374330e2 |
1130 | biglen = len + pad; |
1131 | |
32874aea |
1132 | for (i = 0; i < pad; i++) |
1133 | pktout.data[i + 4] = random_byte(); |
1134 | crc = crc32(pktout.data + 4, biglen - 4); |
1135 | PUT_32BIT(pktout.data + biglen, crc); |
fb09bf1c |
1136 | PUT_32BIT(pktout.data, len); |
374330e2 |
1137 | |
1138 | if (cipher) |
32874aea |
1139 | cipher->encrypt(pktout.data + 4, biglen); |
374330e2 |
1140 | |
32874aea |
1141 | return biglen + 4; |
39065bed |
1142 | } |
1143 | |
32874aea |
1144 | static void s_wrpkt(void) |
1145 | { |
5471d09a |
1146 | int len, backlog; |
39065bed |
1147 | len = s_wrpkt_prepare(); |
5471d09a |
1148 | backlog = sk_write(s, pktout.data, len); |
1149 | if (backlog > SSH_MAX_BACKLOG) |
1150 | ssh_throttle_all(1, backlog); |
39065bed |
1151 | } |
1152 | |
32874aea |
1153 | static void s_wrpkt_defer(void) |
1154 | { |
39065bed |
1155 | int len; |
1156 | len = s_wrpkt_prepare(); |
1157 | if (deferred_len + len > deferred_size) { |
32874aea |
1158 | deferred_size = deferred_len + len + 128; |
1159 | deferred_send_data = srealloc(deferred_send_data, deferred_size); |
39065bed |
1160 | } |
32874aea |
1161 | memcpy(deferred_send_data + deferred_len, pktout.data, len); |
39065bed |
1162 | deferred_len += len; |
374330e2 |
1163 | } |
1164 | |
fb09bf1c |
1165 | /* |
39065bed |
1166 | * Construct a packet with the specified contents. |
fb09bf1c |
1167 | */ |
39065bed |
1168 | static void construct_packet(int pkttype, va_list ap1, va_list ap2) |
fb09bf1c |
1169 | { |
fb09bf1c |
1170 | unsigned char *p, *argp, argchar; |
1171 | unsigned long argint; |
1172 | int pktlen, argtype, arglen; |
7cca0d81 |
1173 | Bignum bn; |
fb09bf1c |
1174 | |
1175 | pktlen = 0; |
39065bed |
1176 | while ((argtype = va_arg(ap1, int)) != PKT_END) { |
fb09bf1c |
1177 | switch (argtype) { |
1178 | case PKT_INT: |
39065bed |
1179 | (void) va_arg(ap1, int); |
fb09bf1c |
1180 | pktlen += 4; |
1181 | break; |
1182 | case PKT_CHAR: |
39065bed |
1183 | (void) va_arg(ap1, char); |
fb09bf1c |
1184 | pktlen++; |
1185 | break; |
1186 | case PKT_DATA: |
39065bed |
1187 | (void) va_arg(ap1, unsigned char *); |
1188 | arglen = va_arg(ap1, int); |
fb09bf1c |
1189 | pktlen += arglen; |
1190 | break; |
1191 | case PKT_STR: |
39065bed |
1192 | argp = va_arg(ap1, unsigned char *); |
fb09bf1c |
1193 | arglen = strlen(argp); |
1194 | pktlen += 4 + arglen; |
1195 | break; |
7cca0d81 |
1196 | case PKT_BIGNUM: |
39065bed |
1197 | bn = va_arg(ap1, Bignum); |
32874aea |
1198 | pktlen += ssh1_bignum_length(bn); |
7cca0d81 |
1199 | break; |
fb09bf1c |
1200 | default: |
1201 | assert(0); |
1202 | } |
1203 | } |
fb09bf1c |
1204 | |
1205 | s_wrpkt_start(pkttype, pktlen); |
1206 | p = pktout.body; |
1207 | |
39065bed |
1208 | while ((argtype = va_arg(ap2, int)) != PKT_END) { |
fb09bf1c |
1209 | switch (argtype) { |
1210 | case PKT_INT: |
39065bed |
1211 | argint = va_arg(ap2, int); |
fb09bf1c |
1212 | PUT_32BIT(p, argint); |
1213 | p += 4; |
1214 | break; |
1215 | case PKT_CHAR: |
39065bed |
1216 | argchar = va_arg(ap2, unsigned char); |
fb09bf1c |
1217 | *p = argchar; |
1218 | p++; |
1219 | break; |
1220 | case PKT_DATA: |
39065bed |
1221 | argp = va_arg(ap2, unsigned char *); |
1222 | arglen = va_arg(ap2, int); |
fb09bf1c |
1223 | memcpy(p, argp, arglen); |
1224 | p += arglen; |
1225 | break; |
1226 | case PKT_STR: |
39065bed |
1227 | argp = va_arg(ap2, unsigned char *); |
fb09bf1c |
1228 | arglen = strlen(argp); |
1229 | PUT_32BIT(p, arglen); |
1230 | memcpy(p + 4, argp, arglen); |
1231 | p += 4 + arglen; |
1232 | break; |
7cca0d81 |
1233 | case PKT_BIGNUM: |
39065bed |
1234 | bn = va_arg(ap2, Bignum); |
32874aea |
1235 | p += ssh1_write_bignum(p, bn); |
7cca0d81 |
1236 | break; |
fb09bf1c |
1237 | } |
1238 | } |
39065bed |
1239 | } |
fb09bf1c |
1240 | |
32874aea |
1241 | static void send_packet(int pkttype, ...) |
1242 | { |
39065bed |
1243 | va_list ap1, ap2; |
1244 | va_start(ap1, pkttype); |
1245 | va_start(ap2, pkttype); |
1246 | construct_packet(pkttype, ap1, ap2); |
fb09bf1c |
1247 | s_wrpkt(); |
1248 | } |
1249 | |
32874aea |
1250 | static void defer_packet(int pkttype, ...) |
1251 | { |
39065bed |
1252 | va_list ap1, ap2; |
1253 | va_start(ap1, pkttype); |
1254 | va_start(ap2, pkttype); |
1255 | construct_packet(pkttype, ap1, ap2); |
1256 | s_wrpkt_defer(); |
1257 | } |
1258 | |
32874aea |
1259 | static int ssh_versioncmp(char *a, char *b) |
1260 | { |
9697bfd2 |
1261 | char *ae, *be; |
1262 | unsigned long av, bv; |
1263 | |
43aa02a7 |
1264 | av = strtoul(a, &ae, 10); |
1265 | bv = strtoul(b, &be, 10); |
32874aea |
1266 | if (av != bv) |
1267 | return (av < bv ? -1 : +1); |
1268 | if (*ae == '.') |
1269 | ae++; |
1270 | if (*be == '.') |
1271 | be++; |
43aa02a7 |
1272 | av = strtoul(ae, &ae, 10); |
1273 | bv = strtoul(be, &be, 10); |
32874aea |
1274 | if (av != bv) |
1275 | return (av < bv ? -1 : +1); |
9697bfd2 |
1276 | return 0; |
1277 | } |
1278 | |
e5574168 |
1279 | |
1280 | /* |
a92dd380 |
1281 | * Utility routines for putting an SSH-protocol `string' and |
1282 | * `uint32' into a SHA state. |
e5574168 |
1283 | */ |
1284 | #include <stdio.h> |
32874aea |
1285 | static void sha_string(SHA_State * s, void *str, int len) |
1286 | { |
e5574168 |
1287 | unsigned char lenblk[4]; |
e5574168 |
1288 | PUT_32BIT(lenblk, len); |
e5574168 |
1289 | SHA_Bytes(s, lenblk, 4); |
e5574168 |
1290 | SHA_Bytes(s, str, len); |
1291 | } |
1292 | |
32874aea |
1293 | static void sha_uint32(SHA_State * s, unsigned i) |
1294 | { |
a92dd380 |
1295 | unsigned char intblk[4]; |
1296 | PUT_32BIT(intblk, i); |
1297 | SHA_Bytes(s, intblk, 4); |
1298 | } |
1299 | |
7cca0d81 |
1300 | /* |
1301 | * SSH2 packet construction functions. |
1302 | */ |
32874aea |
1303 | static void ssh2_pkt_ensure(int length) |
1304 | { |
783415f8 |
1305 | if (pktout.maxlen < length) { |
32874aea |
1306 | pktout.maxlen = length + 256; |
1307 | pktout.data = |
1308 | (pktout.data == |
1309 | NULL ? smalloc(pktout.maxlen + |
1310 | APIEXTRA) : srealloc(pktout.data, |
1311 | pktout.maxlen + |
1312 | APIEXTRA)); |
1313 | if (!pktout.data) |
1314 | fatalbox("Out of memory"); |
7cca0d81 |
1315 | } |
783415f8 |
1316 | } |
32874aea |
1317 | static void ssh2_pkt_adddata(void *data, int len) |
1318 | { |
783415f8 |
1319 | pktout.length += len; |
1320 | ssh2_pkt_ensure(pktout.length); |
32874aea |
1321 | memcpy(pktout.data + pktout.length - len, data, len); |
7cca0d81 |
1322 | } |
32874aea |
1323 | static void ssh2_pkt_addbyte(unsigned char byte) |
1324 | { |
7cca0d81 |
1325 | ssh2_pkt_adddata(&byte, 1); |
1326 | } |
32874aea |
1327 | static void ssh2_pkt_init(int pkt_type) |
1328 | { |
7cca0d81 |
1329 | pktout.length = 5; |
32874aea |
1330 | ssh2_pkt_addbyte((unsigned char) pkt_type); |
7cca0d81 |
1331 | } |
32874aea |
1332 | static void ssh2_pkt_addbool(unsigned char value) |
1333 | { |
7cca0d81 |
1334 | ssh2_pkt_adddata(&value, 1); |
1335 | } |
32874aea |
1336 | static void ssh2_pkt_adduint32(unsigned long value) |
1337 | { |
7cca0d81 |
1338 | unsigned char x[4]; |
1339 | PUT_32BIT(x, value); |
1340 | ssh2_pkt_adddata(x, 4); |
1341 | } |
32874aea |
1342 | static void ssh2_pkt_addstring_start(void) |
1343 | { |
7cca0d81 |
1344 | ssh2_pkt_adduint32(0); |
1345 | pktout.savedpos = pktout.length; |
1346 | } |
32874aea |
1347 | static void ssh2_pkt_addstring_str(char *data) |
1348 | { |
7cca0d81 |
1349 | ssh2_pkt_adddata(data, strlen(data)); |
1350 | PUT_32BIT(pktout.data + pktout.savedpos - 4, |
32874aea |
1351 | pktout.length - pktout.savedpos); |
7cca0d81 |
1352 | } |
32874aea |
1353 | static void ssh2_pkt_addstring_data(char *data, int len) |
1354 | { |
7cca0d81 |
1355 | ssh2_pkt_adddata(data, len); |
1356 | PUT_32BIT(pktout.data + pktout.savedpos - 4, |
32874aea |
1357 | pktout.length - pktout.savedpos); |
7cca0d81 |
1358 | } |
32874aea |
1359 | static void ssh2_pkt_addstring(char *data) |
1360 | { |
7cca0d81 |
1361 | ssh2_pkt_addstring_start(); |
1362 | ssh2_pkt_addstring_str(data); |
1363 | } |
32874aea |
1364 | static char *ssh2_mpint_fmt(Bignum b, int *len) |
1365 | { |
7cca0d81 |
1366 | unsigned char *p; |
32874aea |
1367 | int i, n = (bignum_bitcount(b) + 7) / 8; |
3709bfe9 |
1368 | p = smalloc(n + 1); |
7cca0d81 |
1369 | if (!p) |
32874aea |
1370 | fatalbox("out of memory"); |
7cca0d81 |
1371 | p[0] = 0; |
3709bfe9 |
1372 | for (i = 1; i <= n; i++) |
32874aea |
1373 | p[i] = bignum_byte(b, n - i); |
7cca0d81 |
1374 | i = 0; |
32874aea |
1375 | while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0) |
1376 | i++; |
1377 | memmove(p, p + i, n + 1 - i); |
1378 | *len = n + 1 - i; |
7cca0d81 |
1379 | return p; |
1380 | } |
32874aea |
1381 | static void ssh2_pkt_addmp(Bignum b) |
1382 | { |
7cca0d81 |
1383 | unsigned char *p; |
1384 | int len; |
1385 | p = ssh2_mpint_fmt(b, &len); |
1386 | ssh2_pkt_addstring_start(); |
1387 | ssh2_pkt_addstring_data(p, len); |
dcbde236 |
1388 | sfree(p); |
7cca0d81 |
1389 | } |
b185170a |
1390 | |
1391 | /* |
1392 | * Construct an SSH2 final-form packet: compress it, encrypt it, |
1393 | * put the MAC on it. Final packet, ready to be sent, is stored in |
1394 | * pktout.data. Total length is returned. |
1395 | */ |
32874aea |
1396 | static int ssh2_pkt_construct(void) |
1397 | { |
7cca0d81 |
1398 | int cipherblk, maclen, padding, i; |
1399 | static unsigned long outgoing_sequence = 0; |
1400 | |
00db133f |
1401 | log_packet(PKT_OUTGOING, pktout.data[5], ssh2_pkt_type(pktout.data[5]), |
1402 | pktout.data + 6, pktout.length - 6); |
1403 | |
7cca0d81 |
1404 | /* |
4ba9b64b |
1405 | * Compress packet payload. |
1406 | */ |
4ba9b64b |
1407 | { |
1408 | unsigned char *newpayload; |
1409 | int newlen; |
32874aea |
1410 | if (cscomp && cscomp->compress(pktout.data + 5, pktout.length - 5, |
4ba9b64b |
1411 | &newpayload, &newlen)) { |
1412 | pktout.length = 5; |
1413 | ssh2_pkt_adddata(newpayload, newlen); |
dcbde236 |
1414 | sfree(newpayload); |
4ba9b64b |
1415 | } |
1416 | } |
1417 | |
1418 | /* |
7cca0d81 |
1419 | * Add padding. At least four bytes, and must also bring total |
1420 | * length (minus MAC) up to a multiple of the block size. |
1421 | */ |
32874aea |
1422 | cipherblk = cscipher ? cscipher->blksize : 8; /* block size */ |
1423 | cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */ |
7cca0d81 |
1424 | padding = 4; |
32874aea |
1425 | padding += |
1426 | (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk; |
783415f8 |
1427 | maclen = csmac ? csmac->len : 0; |
1428 | ssh2_pkt_ensure(pktout.length + padding + maclen); |
7cca0d81 |
1429 | pktout.data[4] = padding; |
1430 | for (i = 0; i < padding; i++) |
32874aea |
1431 | pktout.data[pktout.length + i] = random_byte(); |
7cca0d81 |
1432 | PUT_32BIT(pktout.data, pktout.length + padding - 4); |
1433 | if (csmac) |
32874aea |
1434 | csmac->generate(pktout.data, pktout.length + padding, |
1435 | outgoing_sequence); |
1436 | outgoing_sequence++; /* whether or not we MACed */ |
7cca0d81 |
1437 | |
7cca0d81 |
1438 | if (cscipher) |
32874aea |
1439 | cscipher->encrypt(pktout.data, pktout.length + padding); |
7cca0d81 |
1440 | |
b185170a |
1441 | /* Ready-to-send packet starts at pktout.data. We return length. */ |
1442 | return pktout.length + padding + maclen; |
1443 | } |
1444 | |
1445 | /* |
1446 | * Construct and send an SSH2 packet immediately. |
1447 | */ |
32874aea |
1448 | static void ssh2_pkt_send(void) |
1449 | { |
5471d09a |
1450 | int len; |
1451 | int backlog; |
1452 | len = ssh2_pkt_construct(); |
1453 | backlog = sk_write(s, pktout.data, len); |
1454 | if (backlog > SSH_MAX_BACKLOG) |
1455 | ssh_throttle_all(1, backlog); |
b185170a |
1456 | } |
1457 | |
1458 | /* |
1459 | * Construct an SSH2 packet and add it to a deferred data block. |
1460 | * Useful for sending multiple packets in a single sk_write() call, |
1461 | * to prevent a traffic-analysing listener from being able to work |
1462 | * out the length of any particular packet (such as the password |
1463 | * packet). |
1464 | * |
1465 | * Note that because SSH2 sequence-numbers its packets, this can |
1466 | * NOT be used as an m4-style `defer' allowing packets to be |
1467 | * constructed in one order and sent in another. |
1468 | */ |
32874aea |
1469 | static void ssh2_pkt_defer(void) |
1470 | { |
b185170a |
1471 | int len = ssh2_pkt_construct(); |
1472 | if (deferred_len + len > deferred_size) { |
32874aea |
1473 | deferred_size = deferred_len + len + 128; |
1474 | deferred_send_data = srealloc(deferred_send_data, deferred_size); |
b185170a |
1475 | } |
32874aea |
1476 | memcpy(deferred_send_data + deferred_len, pktout.data, len); |
b185170a |
1477 | deferred_len += len; |
1478 | } |
1479 | |
1480 | /* |
1481 | * Send the whole deferred data block constructed by |
39065bed |
1482 | * ssh2_pkt_defer() or SSH1's defer_packet(). |
b185170a |
1483 | */ |
32874aea |
1484 | static void ssh_pkt_defersend(void) |
1485 | { |
5471d09a |
1486 | int backlog; |
1487 | backlog = sk_write(s, deferred_send_data, deferred_len); |
b185170a |
1488 | deferred_len = deferred_size = 0; |
1489 | sfree(deferred_send_data); |
1490 | deferred_send_data = NULL; |
5471d09a |
1491 | if (backlog > SSH_MAX_BACKLOG) |
1492 | ssh_throttle_all(1, backlog); |
7cca0d81 |
1493 | } |
1494 | |
1495 | #if 0 |
32874aea |
1496 | void bndebug(char *string, Bignum b) |
1497 | { |
7cca0d81 |
1498 | unsigned char *p; |
1499 | int i, len; |
1500 | p = ssh2_mpint_fmt(b, &len); |
1501 | debug(("%s", string)); |
1502 | for (i = 0; i < len; i++) |
32874aea |
1503 | debug((" %02x", p[i])); |
765c4200 |
1504 | debug(("\n")); |
dcbde236 |
1505 | sfree(p); |
7cca0d81 |
1506 | } |
1507 | #endif |
1508 | |
32874aea |
1509 | static void sha_mpint(SHA_State * s, Bignum b) |
1510 | { |
7cca0d81 |
1511 | unsigned char *p; |
1512 | int len; |
1513 | p = ssh2_mpint_fmt(b, &len); |
1514 | sha_string(s, p, len); |
dcbde236 |
1515 | sfree(p); |
7cca0d81 |
1516 | } |
1517 | |
1518 | /* |
1519 | * SSH2 packet decode functions. |
1520 | */ |
32874aea |
1521 | static unsigned long ssh2_pkt_getuint32(void) |
1522 | { |
7cca0d81 |
1523 | unsigned long value; |
1524 | if (pktin.length - pktin.savedpos < 4) |
32874aea |
1525 | return 0; /* arrgh, no way to decline (FIXME?) */ |
1526 | value = GET_32BIT(pktin.data + pktin.savedpos); |
7cca0d81 |
1527 | pktin.savedpos += 4; |
1528 | return value; |
1529 | } |
32874aea |
1530 | static int ssh2_pkt_getbool(void) |
1531 | { |
65a22376 |
1532 | unsigned long value; |
1533 | if (pktin.length - pktin.savedpos < 1) |
32874aea |
1534 | return 0; /* arrgh, no way to decline (FIXME?) */ |
65a22376 |
1535 | value = pktin.data[pktin.savedpos] != 0; |
1536 | pktin.savedpos++; |
1537 | return value; |
1538 | } |
32874aea |
1539 | static void ssh2_pkt_getstring(char **p, int *length) |
1540 | { |
7cca0d81 |
1541 | *p = NULL; |
45068b27 |
1542 | *length = 0; |
7cca0d81 |
1543 | if (pktin.length - pktin.savedpos < 4) |
32874aea |
1544 | return; |
1545 | *length = GET_32BIT(pktin.data + pktin.savedpos); |
7cca0d81 |
1546 | pktin.savedpos += 4; |
1547 | if (pktin.length - pktin.savedpos < *length) |
32874aea |
1548 | return; |
1549 | *p = pktin.data + pktin.savedpos; |
7cca0d81 |
1550 | pktin.savedpos += *length; |
1551 | } |
32874aea |
1552 | static Bignum ssh2_pkt_getmp(void) |
1553 | { |
7cca0d81 |
1554 | char *p; |
3709bfe9 |
1555 | int length; |
7cca0d81 |
1556 | Bignum b; |
1557 | |
1558 | ssh2_pkt_getstring(&p, &length); |
1559 | if (!p) |
32874aea |
1560 | return NULL; |
8d5de777 |
1561 | if (p[0] & 0x80) { |
32874aea |
1562 | bombout(("internal error: Can't handle negative mpints")); |
1563 | return NULL; |
8d5de777 |
1564 | } |
3709bfe9 |
1565 | b = bignum_from_bytes(p, length); |
7cca0d81 |
1566 | return b; |
1567 | } |
1568 | |
7d503c31 |
1569 | /* |
1dd353b5 |
1570 | * Helper function to add an SSH2 signature blob to a packet. |
1571 | * Expects to be shown the public key blob as well as the signature |
1572 | * blob. Normally works just like ssh2_pkt_addstring, but will |
1573 | * fiddle with the signature packet if necessary for |
1574 | * BUG_SSH2_RSA_PADDING. |
1575 | */ |
1576 | static void ssh2_add_sigblob(void *pkblob_v, int pkblob_len, |
1577 | void *sigblob_v, int sigblob_len) |
1578 | { |
1579 | unsigned char *pkblob = (unsigned char *)pkblob_v; |
1580 | unsigned char *sigblob = (unsigned char *)sigblob_v; |
1581 | |
1582 | /* dmemdump(pkblob, pkblob_len); */ |
1583 | /* dmemdump(sigblob, sigblob_len); */ |
1584 | |
1585 | /* |
1586 | * See if this is in fact an ssh-rsa signature and a buggy |
1587 | * server; otherwise we can just do this the easy way. |
1588 | */ |
1589 | if ((ssh_remote_bugs & BUG_SSH2_RSA_PADDING) && |
1590 | (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) { |
1591 | int pos, len, siglen; |
1592 | |
1593 | /* |
1594 | * Find the byte length of the modulus. |
1595 | */ |
1596 | |
1597 | pos = 4+7; /* skip over "ssh-rsa" */ |
1598 | pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */ |
1599 | len = GET_32BIT(pkblob+pos); /* find length of modulus */ |
1600 | pos += 4; /* find modulus itself */ |
1601 | while (len > 0 && pkblob[pos] == 0) |
1602 | len--, pos++; |
1603 | /* debug(("modulus length is %d\n", len)); */ |
1604 | |
1605 | /* |
1606 | * Now find the signature integer. |
1607 | */ |
1608 | pos = 4+7; /* skip over "ssh-rsa" */ |
1609 | siglen = GET_32BIT(sigblob+pos); |
1610 | /* debug(("signature length is %d\n", siglen)); */ |
1611 | |
1612 | if (len != siglen) { |
1613 | unsigned char newlen[4]; |
1614 | ssh2_pkt_addstring_start(); |
1615 | ssh2_pkt_addstring_data(sigblob, pos); |
1616 | /* dmemdump(sigblob, pos); */ |
1617 | pos += 4; /* point to start of actual sig */ |
1618 | PUT_32BIT(newlen, len); |
1619 | ssh2_pkt_addstring_data(newlen, 4); |
1620 | /* dmemdump(newlen, 4); */ |
1621 | newlen[0] = 0; |
1622 | while (len-- > siglen) { |
1623 | ssh2_pkt_addstring_data(newlen, 1); |
1624 | /* dmemdump(newlen, 1); */ |
1625 | } |
1626 | ssh2_pkt_addstring_data(sigblob+pos, siglen); |
1627 | /* dmemdump(sigblob+pos, siglen); */ |
1628 | return; |
1629 | } |
1630 | |
1631 | /* Otherwise fall through and do it the easy way. */ |
1632 | } |
1633 | |
1634 | ssh2_pkt_addstring_start(); |
1635 | ssh2_pkt_addstring_data(sigblob, sigblob_len); |
1636 | } |
1637 | |
1638 | /* |
7d503c31 |
1639 | * Examine the remote side's version string and compare it against |
1640 | * a list of known buggy implementations. |
1641 | */ |
32874aea |
1642 | static void ssh_detect_bugs(char *vstring) |
1643 | { |
1644 | char *imp; /* pointer to implementation part */ |
7d503c31 |
1645 | imp = vstring; |
1646 | imp += strcspn(imp, "-"); |
bd358db1 |
1647 | if (*imp) imp++; |
7d503c31 |
1648 | imp += strcspn(imp, "-"); |
bd358db1 |
1649 | if (*imp) imp++; |
7d503c31 |
1650 | |
1651 | ssh_remote_bugs = 0; |
1652 | |
1653 | if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") || |
32874aea |
1654 | !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") || |
bd358db1 |
1655 | !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")) { |
32874aea |
1656 | /* |
1657 | * These versions don't support SSH1_MSG_IGNORE, so we have |
1658 | * to use a different defence against password length |
1659 | * sniffing. |
1660 | */ |
1661 | ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE; |
1662 | logevent("We believe remote version has SSH1 ignore bug"); |
7d503c31 |
1663 | } |
1664 | |
bd358db1 |
1665 | if (!strcmp(imp, "Cisco-1.25")) { |
1666 | /* |
1667 | * These versions need a plain password sent; they can't |
1668 | * handle having a null and a random length of data after |
1669 | * the password. |
1670 | */ |
1671 | ssh_remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD; |
1672 | logevent("We believe remote version needs a plain SSH1 password"); |
1673 | } |
1674 | |
0df73905 |
1675 | if (!strcmp(imp, "Cisco-1.25")) { |
1676 | /* |
1677 | * These versions apparently have no clue whatever about |
1678 | * RSA authentication and will panic and die if they see |
1679 | * an AUTH_RSA message. |
1680 | */ |
1681 | ssh_remote_bugs |= BUG_CHOKES_ON_RSA; |
1682 | logevent("We believe remote version can't handle RSA authentication"); |
1683 | } |
1684 | |
7d503c31 |
1685 | if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) || |
32874aea |
1686 | !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) || |
1687 | !strncmp(imp, "2.1 ", 4)) { |
1688 | /* |
1689 | * These versions have the HMAC bug. |
1690 | */ |
1691 | ssh_remote_bugs |= BUG_SSH2_HMAC; |
1692 | logevent("We believe remote version has SSH2 HMAC bug"); |
7d503c31 |
1693 | } |
1dd353b5 |
1694 | |
1695 | if ((!strncmp(imp, "OpenSSH_2.", 10) && imp[10]>='5' && imp[10]<='9') || |
1696 | (!strncmp(imp, "OpenSSH_3.", 10) && imp[10]>='0' && imp[10]<='2')) { |
1697 | /* |
1698 | * These versions have the SSH2 RSA padding bug. |
1699 | */ |
1700 | ssh_remote_bugs |= BUG_SSH2_RSA_PADDING; |
1701 | logevent("We believe remote version has SSH2 RSA padding bug"); |
1702 | } |
7d503c31 |
1703 | } |
1704 | |
32874aea |
1705 | static int do_ssh_init(unsigned char c) |
1706 | { |
2d466ffd |
1707 | static int vslen; |
8df7a775 |
1708 | static char version[10]; |
50526e47 |
1709 | static char *vstring; |
1710 | static int vstrsize; |
1711 | static char *vlog; |
8df7a775 |
1712 | static int i; |
38d228a2 |
1713 | static int proto1, proto2; |
374330e2 |
1714 | |
8df7a775 |
1715 | crBegin; |
1716 | |
1717 | /* Search for the string "SSH-" in the input. */ |
374330e2 |
1718 | i = 0; |
8df7a775 |
1719 | while (1) { |
1720 | static const int transS[] = { 1, 2, 2, 1 }; |
1721 | static const int transH[] = { 0, 0, 3, 0 }; |
1722 | static const int transminus[] = { 0, 0, 0, -1 }; |
32874aea |
1723 | if (c == 'S') |
1724 | i = transS[i]; |
1725 | else if (c == 'H') |
1726 | i = transH[i]; |
1727 | else if (c == '-') |
1728 | i = transminus[i]; |
1729 | else |
1730 | i = 0; |
8df7a775 |
1731 | if (i < 0) |
1732 | break; |
1733 | crReturn(1); /* get another character */ |
374330e2 |
1734 | } |
8df7a775 |
1735 | |
50526e47 |
1736 | vstrsize = 16; |
bd358db1 |
1737 | vstring = smalloc(vstrsize); |
c5e9c988 |
1738 | strcpy(vstring, "SSH-"); |
50526e47 |
1739 | vslen = 4; |
374330e2 |
1740 | i = 0; |
1741 | while (1) { |
8df7a775 |
1742 | crReturn(1); /* get another char */ |
32874aea |
1743 | if (vslen >= vstrsize - 1) { |
1744 | vstrsize += 16; |
1745 | vstring = srealloc(vstring, vstrsize); |
1746 | } |
1747 | vstring[vslen++] = c; |
374330e2 |
1748 | if (i >= 0) { |
1749 | if (c == '-') { |
1750 | version[i] = '\0'; |
1751 | i = -1; |
32874aea |
1752 | } else if (i < sizeof(version) - 1) |
374330e2 |
1753 | version[i++] = c; |
32874aea |
1754 | } else if (c == '\n') |
374330e2 |
1755 | break; |
1756 | } |
1757 | |
db7d555c |
1758 | ssh_agentfwd_enabled = FALSE; |
960e736a |
1759 | rdpkt2_state.incoming_sequence = 0; |
1760 | |
50526e47 |
1761 | vstring[vslen] = 0; |
9275ca8a |
1762 | vlog = smalloc(20 + vslen); |
bd358db1 |
1763 | vstring[strcspn (vstring, "\r\n")] = '\0'; /* remove end-of-line chars */ |
c5e9c988 |
1764 | sprintf(vlog, "Server version: %s", vstring); |
c5e9c988 |
1765 | logevent(vlog); |
bd358db1 |
1766 | ssh_detect_bugs(vstring); |
9275ca8a |
1767 | sfree(vlog); |
c5e9c988 |
1768 | |
adf799dd |
1769 | /* |
38d228a2 |
1770 | * Decide which SSH protocol version to support. |
adf799dd |
1771 | */ |
38d228a2 |
1772 | |
1773 | /* Anything strictly below "2.0" means protocol 1 is supported. */ |
1774 | proto1 = ssh_versioncmp(version, "2.0") < 0; |
1775 | /* Anything greater or equal to "1.99" means protocol 2 is supported. */ |
daa72738 |
1776 | proto2 = ssh_versioncmp(version, "1.99") >= 0; |
38d228a2 |
1777 | |
1778 | if (cfg.sshprot == 0 && !proto1) { |
1779 | bombout(("SSH protocol version 1 required by user but not provided by server")); |
1780 | crReturn(0); |
1781 | } |
1782 | if (cfg.sshprot == 3 && !proto2) { |
1783 | bombout(("SSH protocol version 2 required by user but not provided by server")); |
1784 | crReturn(0); |
1785 | } |
1786 | |
daa72738 |
1787 | if (proto2 && (cfg.sshprot >= 2 || !proto1)) { |
32874aea |
1788 | /* |
38d228a2 |
1789 | * Use v2 protocol. |
32874aea |
1790 | */ |
1791 | char verstring[80], vlog[100]; |
1792 | sprintf(verstring, "SSH-2.0-%s", sshver); |
1793 | SHA_Init(&exhashbase); |
1794 | /* |
1795 | * Hash our version string and their version string. |
1796 | */ |
1797 | sha_string(&exhashbase, verstring, strlen(verstring)); |
1798 | sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n")); |
1799 | sprintf(vlog, "We claim version: %s", verstring); |
1800 | logevent(vlog); |
1801 | strcat(verstring, "\n"); |
1802 | logevent("Using SSH protocol version 2"); |
1803 | sk_write(s, verstring, strlen(verstring)); |
1804 | ssh_protocol = ssh2_protocol; |
1805 | ssh_version = 2; |
1806 | s_rdpkt = ssh2_rdpkt; |
e5574168 |
1807 | } else { |
32874aea |
1808 | /* |
38d228a2 |
1809 | * Use v1 protocol. |
32874aea |
1810 | */ |
1811 | char verstring[80], vlog[100]; |
1812 | sprintf(verstring, "SSH-%s-%s", |
1813 | (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"), |
1814 | sshver); |
1815 | sprintf(vlog, "We claim version: %s", verstring); |
1816 | logevent(vlog); |
1817 | strcat(verstring, "\n"); |
759712a6 |
1818 | |
32874aea |
1819 | logevent("Using SSH protocol version 1"); |
1820 | sk_write(s, verstring, strlen(verstring)); |
1821 | ssh_protocol = ssh1_protocol; |
1822 | ssh_version = 1; |
1823 | s_rdpkt = ssh1_rdpkt; |
e5574168 |
1824 | } |
3687d221 |
1825 | ssh_state = SSH_STATE_BEFORE_SIZE; |
8df7a775 |
1826 | |
50526e47 |
1827 | sfree(vstring); |
50526e47 |
1828 | |
8df7a775 |
1829 | crFinish(0); |
1830 | } |
1831 | |
1832 | static void ssh_gotdata(unsigned char *data, int datalen) |
1833 | { |
1834 | crBegin; |
1835 | |
1836 | /* |
1837 | * To begin with, feed the characters one by one to the |
1838 | * protocol initialisation / selection function do_ssh_init(). |
1839 | * When that returns 0, we're done with the initial greeting |
1840 | * exchange and can move on to packet discipline. |
1841 | */ |
1842 | while (1) { |
1843 | int ret; |
1844 | if (datalen == 0) |
1845 | crReturnV; /* more data please */ |
1846 | ret = do_ssh_init(*data); |
32874aea |
1847 | data++; |
1848 | datalen--; |
8df7a775 |
1849 | if (ret == 0) |
1850 | break; |
1851 | } |
1852 | |
1853 | /* |
1854 | * We emerge from that loop when the initial negotiation is |
1855 | * over and we have selected an s_rdpkt function. Now pass |
1856 | * everything to s_rdpkt, and then pass the resulting packets |
1857 | * to the proper protocol handler. |
1858 | */ |
1859 | if (datalen == 0) |
1860 | crReturnV; |
1861 | while (1) { |
1862 | while (datalen > 0) { |
32874aea |
1863 | if (s_rdpkt(&data, &datalen) == 0) { |
e14d0f19 |
1864 | if (ssh_state == SSH_STATE_CLOSED) { |
1865 | return; |
1866 | } |
8df7a775 |
1867 | ssh_protocol(NULL, 0, 1); |
1868 | if (ssh_state == SSH_STATE_CLOSED) { |
1869 | return; |
1870 | } |
1871 | } |
1872 | } |
1873 | crReturnV; |
1874 | } |
1875 | crFinishV; |
1876 | } |
1877 | |
32874aea |
1878 | static int ssh_closing(Plug plug, char *error_msg, int error_code, |
1879 | int calling_back) |
1880 | { |
7e78000d |
1881 | ssh_state = SSH_STATE_CLOSED; |
f3ab576e |
1882 | if (s) { |
1883 | sk_close(s); |
1884 | s = NULL; |
1885 | } |
7e78000d |
1886 | if (error_msg) { |
32874aea |
1887 | /* A socket error has occurred. */ |
247308b5 |
1888 | logevent(error_msg); |
32874aea |
1889 | connection_fatal(error_msg); |
7e78000d |
1890 | } else { |
1891 | /* Otherwise, the remote side closed the connection normally. */ |
8df7a775 |
1892 | } |
7e78000d |
1893 | return 0; |
1894 | } |
1895 | |
32874aea |
1896 | static int ssh_receive(Plug plug, int urgent, char *data, int len) |
1897 | { |
1898 | ssh_gotdata(data, len); |
3257deae |
1899 | if (ssh_state == SSH_STATE_CLOSED) { |
32874aea |
1900 | if (s) { |
1901 | sk_close(s); |
1902 | s = NULL; |
1903 | } |
1904 | return 0; |
3257deae |
1905 | } |
fef97f43 |
1906 | return 1; |
374330e2 |
1907 | } |
1908 | |
5471d09a |
1909 | static void ssh_sent(Plug plug, int bufsize) |
1910 | { |
1911 | /* |
1912 | * If the send backlog on the SSH socket itself clears, we |
1913 | * should unthrottle the whole world if it was throttled. |
1914 | */ |
1915 | if (bufsize < SSH_MAX_BACKLOG) |
1916 | ssh_throttle_all(0, bufsize); |
1917 | } |
1918 | |
fb09bf1c |
1919 | /* |
8df7a775 |
1920 | * Connect to specified host and port. |
1921 | * Returns an error message, or NULL on success. |
6e1ebb76 |
1922 | * Also places the canonical host name into `realhost'. It must be |
1923 | * freed by the caller. |
8df7a775 |
1924 | */ |
2184a5d9 |
1925 | static char *connect_to_host(char *host, int port, char **realhost, int nodelay) |
8df7a775 |
1926 | { |
7e78000d |
1927 | static struct plug_function_table fn_table = { |
1928 | ssh_closing, |
5471d09a |
1929 | ssh_receive, |
1930 | ssh_sent, |
1931 | NULL |
7e78000d |
1932 | }, *fn_table_ptr = &fn_table; |
1933 | |
8df7a775 |
1934 | SockAddr addr; |
1935 | char *err; |
1936 | #ifdef FWHACK |
1937 | char *FWhost; |
1938 | int FWport; |
1939 | #endif |
1940 | |
32874aea |
1941 | savedhost = smalloc(1 + strlen(host)); |
8df7a775 |
1942 | if (!savedhost) |
1943 | fatalbox("Out of memory"); |
1944 | strcpy(savedhost, host); |
1945 | |
1946 | if (port < 0) |
1947 | port = 22; /* default ssh port */ |
1948 | savedport = port; |
1949 | |
1950 | #ifdef FWHACK |
1951 | FWhost = host; |
1952 | FWport = port; |
1953 | host = FWSTR; |
1954 | port = 23; |
1955 | #endif |
1956 | |
1957 | /* |
1958 | * Try to find host. |
1959 | */ |
3ad9d396 |
1960 | { |
1961 | char buf[200]; |
1962 | sprintf(buf, "Looking up host \"%.170s\"", host); |
1963 | logevent(buf); |
1964 | } |
8df7a775 |
1965 | addr = sk_namelookup(host, realhost); |
32874aea |
1966 | if ((err = sk_addr_error(addr))) |
8df7a775 |
1967 | return err; |
1968 | |
1969 | #ifdef FWHACK |
6e1ebb76 |
1970 | *realhost = strdup(FWhost); |
8df7a775 |
1971 | #endif |
1972 | |
1973 | /* |
1974 | * Open socket. |
1975 | */ |
3ad9d396 |
1976 | { |
1977 | char buf[200], addrbuf[100]; |
1978 | sk_getaddr(addr, addrbuf, 100); |
1979 | sprintf(buf, "Connecting to %.100s port %d", addrbuf, port); |
1980 | logevent(buf); |
1981 | } |
8eebd221 |
1982 | s = new_connection(addr, *realhost, port, 0, 1, nodelay, &fn_table_ptr); |
67c4ba2e |
1983 | if ((err = sk_socket_error(s))) { |
1984 | s = NULL; |
8df7a775 |
1985 | return err; |
67c4ba2e |
1986 | } |
8df7a775 |
1987 | |
1988 | #ifdef FWHACK |
1989 | sk_write(s, "connect ", 8); |
1990 | sk_write(s, FWhost, strlen(FWhost)); |
1991 | { |
1992 | char buf[20]; |
1993 | sprintf(buf, " %d\n", FWport); |
1994 | sk_write(s, buf, strlen(buf)); |
1995 | } |
1996 | #endif |
1997 | |
1998 | return NULL; |
1999 | } |
2000 | |
2001 | /* |
5471d09a |
2002 | * Throttle or unthrottle the SSH connection. |
2003 | */ |
2004 | static void ssh1_throttle(int adjust) |
2005 | { |
2006 | int old_count = ssh1_throttle_count; |
2007 | ssh1_throttle_count += adjust; |
2008 | assert(ssh1_throttle_count >= 0); |
2009 | if (ssh1_throttle_count && !old_count) { |
2010 | sk_set_frozen(s, 1); |
2011 | } else if (!ssh1_throttle_count && old_count) { |
2012 | sk_set_frozen(s, 0); |
2013 | } |
2014 | } |
2015 | |
2016 | /* |
2017 | * Throttle or unthrottle _all_ local data streams (for when sends |
2018 | * on the SSH connection itself back up). |
2019 | */ |
2020 | static void ssh_throttle_all(int enable, int bufsize) |
2021 | { |
2022 | int i; |
2023 | struct ssh_channel *c; |
2024 | |
2025 | if (enable == ssh_throttled_all) |
2026 | return; |
2027 | ssh_throttled_all = enable; |
2028 | ssh_overall_bufsize = bufsize; |
2029 | if (!ssh_channels) |
2030 | return; |
2031 | for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) { |
2032 | switch (c->type) { |
2033 | case CHAN_MAINSESSION: |
2034 | /* |
2035 | * This is treated separately, outside the switch. |
2036 | */ |
2037 | break; |
2038 | case CHAN_X11: |
2039 | x11_override_throttle(c->u.x11.s, enable); |
2040 | break; |
2041 | case CHAN_AGENT: |
2042 | /* Agent channels require no buffer management. */ |
2043 | break; |
2044 | case CHAN_SOCKDATA: |
2045 | pfd_override_throttle(c->u.x11.s, enable); |
2046 | break; |
2047 | } |
2048 | } |
2049 | } |
2050 | |
2051 | /* |
fb09bf1c |
2052 | * Handle the key exchange and user authentication phases. |
2053 | */ |
e5574168 |
2054 | static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) |
fb09bf1c |
2055 | { |
2d466ffd |
2056 | int i, j; |
2057 | static int len; |
2058 | static unsigned char *rsabuf, *keystr1, *keystr2; |
374330e2 |
2059 | unsigned char cookie[8]; |
2060 | struct RSAKey servkey, hostkey; |
2061 | struct MD5Context md5c; |
ccbfb941 |
2062 | static unsigned long supported_ciphers_mask, supported_auths_mask; |
67b59fbb |
2063 | static int tried_publickey, tried_agent; |
614a20a0 |
2064 | static int tis_auth_refused, ccard_auth_refused; |
7cca0d81 |
2065 | static unsigned char session_id[16]; |
2d466ffd |
2066 | static int cipher_type; |
b585ec46 |
2067 | static char username[100]; |
396778f1 |
2068 | static void *publickey_blob; |
2069 | int publickey_bloblen; |
374330e2 |
2070 | |
374330e2 |
2071 | crBegin; |
2072 | |
32874aea |
2073 | if (!ispkt) |
2074 | crWaitUntil(ispkt); |
374330e2 |
2075 | |
8d5de777 |
2076 | if (pktin.type != SSH1_SMSG_PUBLIC_KEY) { |
2077 | bombout(("Public key packet not received")); |
32874aea |
2078 | crReturn(0); |
8d5de777 |
2079 | } |
374330e2 |
2080 | |
c5e9c988 |
2081 | logevent("Received public keys"); |
374330e2 |
2082 | |
c5e9c988 |
2083 | memcpy(cookie, pktin.body, 8); |
374330e2 |
2084 | |
32874aea |
2085 | i = makekey(pktin.body + 8, &servkey, &keystr1, 0); |
2086 | j = makekey(pktin.body + 8 + i, &hostkey, &keystr2, 0); |
374330e2 |
2087 | |
c5e9c988 |
2088 | /* |
1c2a93c4 |
2089 | * Log the host key fingerprint. |
c5e9c988 |
2090 | */ |
c5e9c988 |
2091 | { |
2092 | char logmsg[80]; |
1c2a93c4 |
2093 | logevent("Host key fingerprint is:"); |
c5e9c988 |
2094 | strcpy(logmsg, " "); |
32874aea |
2095 | hostkey.comment = NULL; |
2096 | rsa_fingerprint(logmsg + strlen(logmsg), |
2097 | sizeof(logmsg) - strlen(logmsg), &hostkey); |
c5e9c988 |
2098 | logevent(logmsg); |
2099 | } |
2100 | |
32874aea |
2101 | ssh1_remote_protoflags = GET_32BIT(pktin.body + 8 + i + j); |
2102 | supported_ciphers_mask = GET_32BIT(pktin.body + 12 + i + j); |
2103 | supported_auths_mask = GET_32BIT(pktin.body + 16 + i + j); |
bea1ef5f |
2104 | |
32874aea |
2105 | ssh1_local_protoflags = |
2106 | ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED; |
b96dc54c |
2107 | ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER; |
2108 | |
c5e9c988 |
2109 | MD5Init(&md5c); |
374330e2 |
2110 | MD5Update(&md5c, keystr2, hostkey.bytes); |
2111 | MD5Update(&md5c, keystr1, servkey.bytes); |
2112 | MD5Update(&md5c, pktin.body, 8); |
374330e2 |
2113 | MD5Final(session_id, &md5c); |
2114 | |
32874aea |
2115 | for (i = 0; i < 32; i++) |
374330e2 |
2116 | session_key[i] = random_byte(); |
2117 | |
2118 | len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes); |
2119 | |
dcbde236 |
2120 | rsabuf = smalloc(len); |
374330e2 |
2121 | if (!rsabuf) |
2122 | fatalbox("Out of memory"); |
2123 | |
89ee5268 |
2124 | /* |
2125 | * Verify the host key. |
2126 | */ |
2127 | { |
32874aea |
2128 | /* |
2129 | * First format the key into a string. |
2130 | */ |
2131 | int len = rsastr_len(&hostkey); |
2132 | char fingerprint[100]; |
2133 | char *keystr = smalloc(len); |
2134 | if (!keystr) |
2135 | fatalbox("Out of memory"); |
2136 | rsastr_fmt(keystr, &hostkey); |
2137 | rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey); |
2138 | verify_ssh_host_key(savedhost, savedport, "rsa", keystr, |
2139 | fingerprint); |
2140 | sfree(keystr); |
2141 | } |
2142 | |
2143 | for (i = 0; i < 32; i++) { |
374330e2 |
2144 | rsabuf[i] = session_key[i]; |
2145 | if (i < 16) |
2146 | rsabuf[i] ^= session_id[i]; |
2147 | } |
2148 | |
2149 | if (hostkey.bytes > servkey.bytes) { |
2150 | rsaencrypt(rsabuf, 32, &servkey); |
2151 | rsaencrypt(rsabuf, servkey.bytes, &hostkey); |
2152 | } else { |
2153 | rsaencrypt(rsabuf, 32, &hostkey); |
2154 | rsaencrypt(rsabuf, hostkey.bytes, &servkey); |
2155 | } |
2156 | |
c5e9c988 |
2157 | logevent("Encrypted session key"); |
2158 | |
ca20bfcf |
2159 | { |
2160 | int cipher_chosen = 0, warn = 0; |
2161 | char *cipher_string = NULL; |
2162 | for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) { |
2163 | int next_cipher = cfg.ssh_cipherlist[i]; |
2164 | if (next_cipher == CIPHER_WARN) { |
2165 | /* If/when we choose a cipher, warn about it */ |
2166 | warn = 1; |
2167 | } else if (next_cipher == CIPHER_AES) { |
2168 | /* XXX Probably don't need to mention this. */ |
2169 | logevent("AES not supported in SSH1, skipping"); |
2170 | } else { |
2171 | switch (next_cipher) { |
2172 | case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES; |
2173 | cipher_string = "3DES"; break; |
2174 | case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH; |
2175 | cipher_string = "Blowfish"; break; |
2176 | case CIPHER_DES: cipher_type = SSH_CIPHER_DES; |
2177 | cipher_string = "single-DES"; break; |
2178 | } |
2179 | if (supported_ciphers_mask & (1 << cipher_type)) |
2180 | cipher_chosen = 1; |
2181 | } |
2182 | } |
2183 | if (!cipher_chosen) { |
2184 | if ((supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0) |
2185 | bombout(("Server violates SSH 1 protocol by not " |
2186 | "supporting 3DES encryption")); |
2187 | else |
2188 | /* shouldn't happen */ |
2189 | bombout(("No supported ciphers found")); |
a99a05c0 |
2190 | crReturn(0); |
2191 | } |
ca20bfcf |
2192 | |
2193 | /* Warn about chosen cipher if necessary. */ |
2194 | if (warn) |
2195 | askcipher(cipher_string, 0); |
bea1ef5f |
2196 | } |
ca20bfcf |
2197 | |
c5e9c988 |
2198 | switch (cipher_type) { |
32874aea |
2199 | case SSH_CIPHER_3DES: |
2200 | logevent("Using 3DES encryption"); |
2201 | break; |
2202 | case SSH_CIPHER_DES: |
2203 | logevent("Using single-DES encryption"); |
2204 | break; |
2205 | case SSH_CIPHER_BLOWFISH: |
2206 | logevent("Using Blowfish encryption"); |
2207 | break; |
c5e9c988 |
2208 | } |
bea1ef5f |
2209 | |
e5574168 |
2210 | send_packet(SSH1_CMSG_SESSION_KEY, |
32874aea |
2211 | PKT_CHAR, cipher_type, |
2212 | PKT_DATA, cookie, 8, |
2213 | PKT_CHAR, (len * 8) >> 8, PKT_CHAR, (len * 8) & 0xFF, |
2214 | PKT_DATA, rsabuf, len, |
2215 | PKT_INT, ssh1_local_protoflags, PKT_END); |
fb09bf1c |
2216 | |
c5e9c988 |
2217 | logevent("Trying to enable encryption..."); |
374330e2 |
2218 | |
dcbde236 |
2219 | sfree(rsabuf); |
374330e2 |
2220 | |
5e8358ad |
2221 | cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 : |
32874aea |
2222 | cipher_type == SSH_CIPHER_DES ? &ssh_des : &ssh_3des; |
374330e2 |
2223 | cipher->sesskey(session_key); |
2224 | |
fb09bf1c |
2225 | crWaitUntil(ispkt); |
374330e2 |
2226 | |
8d5de777 |
2227 | if (pktin.type != SSH1_SMSG_SUCCESS) { |
2228 | bombout(("Encryption not successfully enabled")); |
32874aea |
2229 | crReturn(0); |
8d5de777 |
2230 | } |
374330e2 |
2231 | |
c5e9c988 |
2232 | logevent("Successfully started encryption"); |
2233 | |
374330e2 |
2234 | fflush(stdout); |
2235 | { |
374330e2 |
2236 | static int pos = 0; |
2237 | static char c; |
67779be7 |
2238 | if ((flags & FLAG_INTERACTIVE) && !*cfg.username) { |
c0a81592 |
2239 | if (ssh_get_line && !ssh_getline_pw_only) { |
32874aea |
2240 | if (!ssh_get_line("login as: ", |
2241 | username, sizeof(username), FALSE)) { |
2242 | /* |
2243 | * get_line failed to get a username. |
2244 | * Terminate. |
2245 | */ |
2246 | logevent("No username provided. Abandoning session."); |
2247 | ssh_state = SSH_STATE_CLOSED; |
2248 | crReturn(1); |
2249 | } |
2250 | } else { |
2251 | c_write_str("login as: "); |
2252 | ssh_send_ok = 1; |
2253 | while (pos >= 0) { |
2254 | crWaitUntil(!ispkt); |
2255 | while (inlen--) |
2256 | switch (c = *in++) { |
2257 | case 10: |
2258 | case 13: |
2259 | username[pos] = 0; |
2260 | pos = -1; |
2261 | break; |
2262 | case 8: |
2263 | case 127: |
2264 | if (pos > 0) { |
2265 | c_write_str("\b \b"); |
2266 | pos--; |
2267 | } |
2268 | break; |
2269 | case 21: |
2270 | case 27: |
2271 | while (pos > 0) { |
2272 | c_write_str("\b \b"); |
2273 | pos--; |
2274 | } |
2275 | break; |
2276 | case 3: |
2277 | case 4: |
93b581bd |
2278 | cleanup_exit(0); |
32874aea |
2279 | break; |
2280 | default: |
2281 | if (((c >= ' ' && c <= '~') || |
51b2fb65 |
2282 | ((unsigned char) c >= 160)) |
2283 | && pos < sizeof(username)-1) { |
32874aea |
2284 | username[pos++] = c; |
2285 | c_write(&c, 1); |
2286 | } |
2287 | break; |
2288 | } |
2289 | } |
2290 | c_write_str("\r\n"); |
2291 | username[strcspn(username, "\n\r")] = '\0'; |
2292 | } |
2293 | } else { |
374330e2 |
2294 | strncpy(username, cfg.username, 99); |
2295 | username[99] = '\0'; |
374330e2 |
2296 | } |
fb09bf1c |
2297 | |
e5574168 |
2298 | send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END); |
c5e9c988 |
2299 | { |
32874aea |
2300 | char userlog[22 + sizeof(username)]; |
c5e9c988 |
2301 | sprintf(userlog, "Sent username \"%s\"", username); |
2302 | logevent(userlog); |
32874aea |
2303 | if (flags & FLAG_INTERACTIVE && |
2304 | (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) { |
3c8e959b |
2305 | strcat(userlog, "\r\n"); |
32874aea |
2306 | c_write_str(userlog); |
3c8e959b |
2307 | } |
c5e9c988 |
2308 | } |
374330e2 |
2309 | } |
2310 | |
fb09bf1c |
2311 | crWaitUntil(ispkt); |
374330e2 |
2312 | |
0df73905 |
2313 | if ((ssh_remote_bugs & BUG_CHOKES_ON_RSA)) { |
2314 | /* We must not attempt PK auth. Pretend we've already tried it. */ |
2315 | tried_publickey = tried_agent = 1; |
2316 | } else { |
2317 | tried_publickey = tried_agent = 0; |
2318 | } |
614a20a0 |
2319 | tis_auth_refused = ccard_auth_refused = 0; |
396778f1 |
2320 | /* Load the public half of cfg.keyfile so we notice if it's in Pageant */ |
2321 | if (*cfg.keyfile) { |
2322 | if (!rsakey_pubblob(cfg.keyfile, &publickey_blob, &publickey_bloblen)) |
2323 | publickey_blob = NULL; |
2324 | } else |
2325 | publickey_blob = NULL; |
7cca0d81 |
2326 | |
e5574168 |
2327 | while (pktin.type == SSH1_SMSG_FAILURE) { |
374330e2 |
2328 | static char password[100]; |
a52f067e |
2329 | static char prompt[200]; |
374330e2 |
2330 | static int pos; |
2331 | static char c; |
32874aea |
2332 | static int pwpkt_type; |
32874aea |
2333 | pwpkt_type = SSH1_CMSG_AUTH_PASSWORD; |
614a20a0 |
2334 | |
67b59fbb |
2335 | if (agent_exists() && !tried_agent) { |
32874aea |
2336 | /* |
2337 | * Attempt RSA authentication using Pageant. |
2338 | */ |
2339 | static unsigned char request[5], *response, *p; |
2340 | static int responselen; |
2341 | static int i, nkeys; |
2342 | static int authed = FALSE; |
2343 | void *r; |
2344 | |
67b59fbb |
2345 | tried_agent = 1; |
32874aea |
2346 | logevent("Pageant is running. Requesting keys."); |
2347 | |
2348 | /* Request the keys held by the agent. */ |
2349 | PUT_32BIT(request, 1); |
2350 | request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES; |
2351 | agent_query(request, 5, &r, &responselen); |
2352 | response = (unsigned char *) r; |
2353 | if (response && responselen >= 5 && |
2354 | response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) { |
2355 | p = response + 5; |
2356 | nkeys = GET_32BIT(p); |
2357 | p += 4; |
2358 | { |
2359 | char buf[64]; |
2360 | sprintf(buf, "Pageant has %d SSH1 keys", nkeys); |
2361 | logevent(buf); |
2362 | } |
2363 | for (i = 0; i < nkeys; i++) { |
2364 | static struct RSAKey key; |
2365 | static Bignum challenge; |
2366 | static char *commentp; |
2367 | static int commentlen; |
2368 | |
2369 | { |
2370 | char buf[64]; |
2371 | sprintf(buf, "Trying Pageant key #%d", i); |
2372 | logevent(buf); |
2373 | } |
396778f1 |
2374 | if (publickey_blob && |
2375 | !memcmp(p, publickey_blob, publickey_bloblen)) { |
2376 | logevent("This key matches configured key file"); |
2377 | tried_publickey = 1; |
2378 | } |
32874aea |
2379 | p += 4; |
2380 | p += ssh1_read_bignum(p, &key.exponent); |
2381 | p += ssh1_read_bignum(p, &key.modulus); |
2382 | commentlen = GET_32BIT(p); |
2383 | p += 4; |
2384 | commentp = p; |
2385 | p += commentlen; |
2386 | send_packet(SSH1_CMSG_AUTH_RSA, |
2387 | PKT_BIGNUM, key.modulus, PKT_END); |
2388 | crWaitUntil(ispkt); |
2389 | if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { |
2390 | logevent("Key refused"); |
2391 | continue; |
2392 | } |
2393 | logevent("Received RSA challenge"); |
2394 | ssh1_read_bignum(pktin.body, &challenge); |
2395 | { |
2396 | char *agentreq, *q, *ret; |
2d466ffd |
2397 | void *vret; |
32874aea |
2398 | int len, retlen; |
2399 | len = 1 + 4; /* message type, bit count */ |
2400 | len += ssh1_bignum_length(key.exponent); |
2401 | len += ssh1_bignum_length(key.modulus); |
2402 | len += ssh1_bignum_length(challenge); |
2403 | len += 16; /* session id */ |
2404 | len += 4; /* response format */ |
2405 | agentreq = smalloc(4 + len); |
2406 | PUT_32BIT(agentreq, len); |
2407 | q = agentreq + 4; |
2408 | *q++ = SSH1_AGENTC_RSA_CHALLENGE; |
2409 | PUT_32BIT(q, bignum_bitcount(key.modulus)); |
2410 | q += 4; |
2411 | q += ssh1_write_bignum(q, key.exponent); |
2412 | q += ssh1_write_bignum(q, key.modulus); |
2413 | q += ssh1_write_bignum(q, challenge); |
2414 | memcpy(q, session_id, 16); |
2415 | q += 16; |
2416 | PUT_32BIT(q, 1); /* response format */ |
2d466ffd |
2417 | agent_query(agentreq, len + 4, &vret, &retlen); |
2418 | ret = vret; |
32874aea |
2419 | sfree(agentreq); |
2420 | if (ret) { |
2421 | if (ret[4] == SSH1_AGENT_RSA_RESPONSE) { |
2422 | logevent("Sending Pageant's response"); |
2423 | send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE, |
2424 | PKT_DATA, ret + 5, 16, |
2425 | PKT_END); |
2426 | sfree(ret); |
2427 | crWaitUntil(ispkt); |
2428 | if (pktin.type == SSH1_SMSG_SUCCESS) { |
2429 | logevent |
2430 | ("Pageant's response accepted"); |
2431 | if (flags & FLAG_VERBOSE) { |
2432 | c_write_str |
2433 | ("Authenticated using RSA key \""); |
2434 | c_write(commentp, commentlen); |
2435 | c_write_str("\" from agent\r\n"); |
2436 | } |
2437 | authed = TRUE; |
2438 | } else |
2439 | logevent |
2440 | ("Pageant's response not accepted"); |
2441 | } else { |
2442 | logevent |
2443 | ("Pageant failed to answer challenge"); |
2444 | sfree(ret); |
2445 | } |
2446 | } else { |
2447 | logevent("No reply received from Pageant"); |
2448 | } |
2449 | } |
2450 | freebn(key.exponent); |
2451 | freebn(key.modulus); |
2452 | freebn(challenge); |
2453 | if (authed) |
2454 | break; |
2455 | } |
2456 | } |
2457 | if (authed) |
2458 | break; |
2459 | } |
2460 | if (*cfg.keyfile && !tried_publickey) |
2461 | pwpkt_type = SSH1_CMSG_AUTH_RSA; |
2462 | |
614a20a0 |
2463 | if (cfg.try_tis_auth && |
2464 | (supported_auths_mask & (1 << SSH1_AUTH_TIS)) && |
2465 | !tis_auth_refused) { |
32874aea |
2466 | pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE; |
2467 | logevent("Requested TIS authentication"); |
2468 | send_packet(SSH1_CMSG_AUTH_TIS, PKT_END); |
2469 | crWaitUntil(ispkt); |
2470 | if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) { |
2471 | logevent("TIS authentication declined"); |
2472 | if (flags & FLAG_INTERACTIVE) |
2473 | c_write_str("TIS authentication refused.\r\n"); |
614a20a0 |
2474 | tis_auth_refused = 1; |
2475 | continue; |
32874aea |
2476 | } else { |
2477 | int challengelen = ((pktin.body[0] << 24) | |
2478 | (pktin.body[1] << 16) | |
2479 | (pktin.body[2] << 8) | |
2480 | (pktin.body[3])); |
2481 | logevent("Received TIS challenge"); |
2482 | if (challengelen > sizeof(prompt) - 1) |
2483 | challengelen = sizeof(prompt) - 1; /* prevent overrun */ |
2484 | memcpy(prompt, pktin.body + 4, challengelen); |
614a20a0 |
2485 | /* Prompt heuristic comes from OpenSSH */ |
2486 | strncpy(prompt + challengelen, |
2487 | memchr(prompt, '\n', challengelen) ? |
2488 | "": "\r\nResponse: ", |
2489 | (sizeof prompt) - challengelen); |
2490 | prompt[(sizeof prompt) - 1] = '\0'; |
32874aea |
2491 | } |
2492 | } |
614a20a0 |
2493 | if (cfg.try_tis_auth && |
2494 | (supported_auths_mask & (1 << SSH1_AUTH_CCARD)) && |
2495 | !ccard_auth_refused) { |
32874aea |
2496 | pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE; |
2497 | logevent("Requested CryptoCard authentication"); |
2498 | send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END); |
2499 | crWaitUntil(ispkt); |
2500 | if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) { |
2501 | logevent("CryptoCard authentication declined"); |
2502 | c_write_str("CryptoCard authentication refused.\r\n"); |
614a20a0 |
2503 | ccard_auth_refused = 1; |
2504 | continue; |
32874aea |
2505 | } else { |
2506 | int challengelen = ((pktin.body[0] << 24) | |
2507 | (pktin.body[1] << 16) | |
2508 | (pktin.body[2] << 8) | |
2509 | (pktin.body[3])); |
2510 | logevent("Received CryptoCard challenge"); |
2511 | if (challengelen > sizeof(prompt) - 1) |
2512 | challengelen = sizeof(prompt) - 1; /* prevent overrun */ |
2513 | memcpy(prompt, pktin.body + 4, challengelen); |
614a20a0 |
2514 | strncpy(prompt + challengelen, |
2515 | memchr(prompt, '\n', challengelen) ? |
2516 | "" : "\r\nResponse: ", |
32874aea |
2517 | sizeof(prompt) - challengelen); |
2518 | prompt[sizeof(prompt) - 1] = '\0'; |
2519 | } |
2520 | } |
2521 | if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) { |
2522 | sprintf(prompt, "%.90s@%.90s's password: ", |
2523 | username, savedhost); |
2524 | } |
2525 | if (pwpkt_type == SSH1_CMSG_AUTH_RSA) { |
2526 | char *comment = NULL; |
231ee168 |
2527 | int type; |
2528 | char msgbuf[256]; |
32874aea |
2529 | if (flags & FLAG_VERBOSE) |
2530 | c_write_str("Trying public key authentication.\r\n"); |
231ee168 |
2531 | sprintf(msgbuf, "Trying public key \"%.200s\"", cfg.keyfile); |
2532 | logevent(msgbuf); |
2533 | type = key_type(cfg.keyfile); |
2534 | if (type != SSH_KEYTYPE_SSH1) { |
2535 | sprintf(msgbuf, "Key is of wrong type (%s)", |
2536 | key_type_to_str(type)); |
2537 | logevent(msgbuf); |
2538 | c_write_str(msgbuf); |
2539 | c_write_str("\r\n"); |
2540 | tried_publickey = 1; |
2541 | continue; |
2542 | } |
32874aea |
2543 | if (!rsakey_encrypted(cfg.keyfile, &comment)) { |
2544 | if (flags & FLAG_VERBOSE) |
2545 | c_write_str("No passphrase required.\r\n"); |
2546 | goto tryauth; |
2547 | } |
2548 | sprintf(prompt, "Passphrase for key \"%.100s\": ", comment); |
2549 | sfree(comment); |
2550 | } |
a52f067e |
2551 | |
614a20a0 |
2552 | /* |
2553 | * Show password prompt, having first obtained it via a TIS |
2554 | * or CryptoCard exchange if we're doing TIS or CryptoCard |
2555 | * authentication. |
2556 | */ |
fa17a66e |
2557 | if (ssh_get_line) { |
2558 | if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) { |
32874aea |
2559 | /* |
2560 | * get_line failed to get a password (for example |
2561 | * because one was supplied on the command line |
2562 | * which has already failed to work). Terminate. |
2563 | */ |
2bc6a386 |
2564 | send_packet(SSH1_MSG_DISCONNECT, |
2565 | PKT_STR, "No more passwords available to try", |
2566 | PKT_END); |
247308b5 |
2567 | logevent("Unable to authenticate"); |
2bc6a386 |
2568 | connection_fatal("Unable to authenticate"); |
32874aea |
2569 | ssh_state = SSH_STATE_CLOSED; |
2570 | crReturn(1); |
2571 | } |
fb09bf1c |
2572 | } else { |
614a20a0 |
2573 | /* Prompt may have come from server. We've munged it a bit, so |
2574 | * we know it to be zero-terminated at least once. */ |
2575 | c_write_untrusted(prompt, strlen(prompt)); |
32874aea |
2576 | pos = 0; |
2577 | ssh_send_ok = 1; |
2578 | while (pos >= 0) { |
2579 | crWaitUntil(!ispkt); |
2580 | while (inlen--) |
2581 | switch (c = *in++) { |
2582 | case 10: |
2583 | case 13: |
2584 | password[pos] = 0; |
2585 | pos = -1; |
2586 | break; |
2587 | case 8: |
2588 | case 127: |
2589 | if (pos > 0) |
2590 | pos--; |
2591 | break; |
2592 | case 21: |
2593 | case 27: |
2594 | pos = 0; |
2595 | break; |
2596 | case 3: |
2597 | case 4: |
93b581bd |
2598 | cleanup_exit(0); |
32874aea |
2599 | break; |
2600 | default: |
51b2fb65 |
2601 | if (pos < sizeof(password)-1) |
32874aea |
2602 | password[pos++] = c; |
2603 | break; |
2604 | } |
2605 | } |
2606 | c_write_str("\r\n"); |
2607 | } |
2608 | |
2609 | tryauth: |
7cca0d81 |
2610 | if (pwpkt_type == SSH1_CMSG_AUTH_RSA) { |
32874aea |
2611 | /* |
2612 | * Try public key authentication with the specified |
2613 | * key file. |
2614 | */ |
2615 | static struct RSAKey pubkey; |
2616 | static Bignum challenge, response; |
2617 | static int i; |
2618 | static unsigned char buffer[32]; |
2619 | |
2620 | tried_publickey = 1; |
2621 | i = loadrsakey(cfg.keyfile, &pubkey, password); |
2622 | if (i == 0) { |
7963af2f |
2623 | c_write_str("Couldn't load private key from "); |
32874aea |
2624 | c_write_str(cfg.keyfile); |
2625 | c_write_str(".\r\n"); |
2626 | continue; /* go and try password */ |
2627 | } |
2628 | if (i == -1) { |
2629 | c_write_str("Wrong passphrase.\r\n"); |
2630 | tried_publickey = 0; |
2631 | continue; /* try again */ |
2632 | } |
2633 | |
2634 | /* |
2635 | * Send a public key attempt. |
2636 | */ |
2637 | send_packet(SSH1_CMSG_AUTH_RSA, |
2638 | PKT_BIGNUM, pubkey.modulus, PKT_END); |
2639 | |
2640 | crWaitUntil(ispkt); |
2641 | if (pktin.type == SSH1_SMSG_FAILURE) { |
2642 | c_write_str("Server refused our public key.\r\n"); |
2643 | continue; /* go and try password */ |
2644 | } |
2645 | if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { |
2646 | bombout(("Bizarre response to offer of public key")); |
2647 | crReturn(0); |
2648 | } |
2649 | ssh1_read_bignum(pktin.body, &challenge); |
2650 | response = rsadecrypt(challenge, &pubkey); |
2651 | freebn(pubkey.private_exponent); /* burn the evidence */ |
2652 | |
2653 | for (i = 0; i < 32; i++) { |
2654 | buffer[i] = bignum_byte(response, 31 - i); |
2655 | } |
2656 | |
2657 | MD5Init(&md5c); |
2658 | MD5Update(&md5c, buffer, 32); |
2659 | MD5Update(&md5c, session_id, 16); |
2660 | MD5Final(buffer, &md5c); |
2661 | |
2662 | send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE, |
2663 | PKT_DATA, buffer, 16, PKT_END); |
2664 | |
2665 | crWaitUntil(ispkt); |
2666 | if (pktin.type == SSH1_SMSG_FAILURE) { |
2667 | if (flags & FLAG_VERBOSE) |
2668 | c_write_str |
2669 | ("Failed to authenticate with our public key.\r\n"); |
2670 | continue; /* go and try password */ |
2671 | } else if (pktin.type != SSH1_SMSG_SUCCESS) { |
2672 | bombout( |
2673 | ("Bizarre response to RSA authentication response")); |
2674 | crReturn(0); |
2675 | } |
2676 | |
2677 | break; /* we're through! */ |
2678 | } else { |
2679 | if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) { |
2680 | /* |
2681 | * Defence against traffic analysis: we send a |
2682 | * whole bunch of packets containing strings of |
2683 | * different lengths. One of these strings is the |
2684 | * password, in a SSH1_CMSG_AUTH_PASSWORD packet. |
2685 | * The others are all random data in |
2686 | * SSH1_MSG_IGNORE packets. This way a passive |
2687 | * listener can't tell which is the password, and |
2688 | * hence can't deduce the password length. |
2689 | * |
2690 | * Anybody with a password length greater than 16 |
2691 | * bytes is going to have enough entropy in their |
2692 | * password that a listener won't find it _that_ |
2693 | * much help to know how long it is. So what we'll |
2694 | * do is: |
2695 | * |
2696 | * - if password length < 16, we send 15 packets |
2697 | * containing string lengths 1 through 15 |
2698 | * |
2699 | * - otherwise, we let N be the nearest multiple |
2700 | * of 8 below the password length, and send 8 |
2701 | * packets containing string lengths N through |
2702 | * N+7. This won't obscure the order of |
2703 | * magnitude of the password length, but it will |
2704 | * introduce a bit of extra uncertainty. |
2705 | * |
2706 | * A few servers (the old 1.2.18 through 1.2.22) |
2707 | * can't deal with SSH1_MSG_IGNORE. For these |
2708 | * servers, we need an alternative defence. We make |
2709 | * use of the fact that the password is interpreted |
2710 | * as a C string: so we can append a NUL, then some |
2711 | * random data. |
bd358db1 |
2712 | * |
2713 | * One server (a Cisco one) can deal with neither |
2714 | * SSH1_MSG_IGNORE _nor_ a padded password string. |
2715 | * For this server we are left with no defences |
2716 | * against password length sniffing. |
32874aea |
2717 | */ |
bd358db1 |
2718 | if (!(ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) { |
b17c8428 |
2719 | /* |
2720 | * The server can deal with SSH1_MSG_IGNORE, so |
2721 | * we can use the primary defence. |
2722 | */ |
32874aea |
2723 | int bottom, top, pwlen, i; |
2724 | char *randomstr; |
2725 | |
2726 | pwlen = strlen(password); |
2727 | if (pwlen < 16) { |
2728 | bottom = 0; /* zero length passwords are OK! :-) */ |
2729 | top = 15; |
2730 | } else { |
2731 | bottom = pwlen & ~7; |
2732 | top = bottom + 7; |
2733 | } |
2734 | |
2735 | assert(pwlen >= bottom && pwlen <= top); |
2736 | |
2737 | randomstr = smalloc(top + 1); |
2738 | |
2739 | for (i = bottom; i <= top; i++) { |
2740 | if (i == pwlen) |
2741 | defer_packet(pwpkt_type, PKT_STR, password, |
2742 | PKT_END); |
2743 | else { |
2744 | for (j = 0; j < i; j++) { |
2745 | do { |
2746 | randomstr[j] = random_byte(); |
2747 | } while (randomstr[j] == '\0'); |
2748 | } |
2749 | randomstr[i] = '\0'; |
2750 | defer_packet(SSH1_MSG_IGNORE, |
2751 | PKT_STR, randomstr, PKT_END); |
2752 | } |
2753 | } |
bd358db1 |
2754 | logevent("Sending password with camouflage packets"); |
32874aea |
2755 | ssh_pkt_defersend(); |
bd358db1 |
2756 | } |
2757 | else if (!(ssh_remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) { |
b17c8428 |
2758 | /* |
2759 | * The server can't deal with SSH1_MSG_IGNORE |
2760 | * but can deal with padded passwords, so we |
2761 | * can use the secondary defence. |
2762 | */ |
bd358db1 |
2763 | char string[64]; |
2764 | char *s; |
2765 | int len; |
2766 | |
2767 | len = strlen(password); |
2768 | if (len < sizeof(string)) { |
2769 | s = string; |
2770 | strcpy(string, password); |
2771 | len++; /* cover the zero byte */ |
2772 | while (len < sizeof(string)) { |
2773 | string[len++] = (char) random_byte(); |
2774 | } |
2775 | } else { |
2776 | s = password; |
2777 | } |
2778 | logevent("Sending length-padded password"); |
2779 | send_packet(pwpkt_type, PKT_INT, len, |
2780 | PKT_DATA, s, len, PKT_END); |
2781 | } else { |
2782 | /* |
2783 | * The server has _both_ |
2784 | * BUG_CHOKES_ON_SSH1_IGNORE and |
2785 | * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is |
2786 | * therefore nothing we can do. |
2787 | */ |
2788 | int len; |
2789 | len = strlen(password); |
2790 | logevent("Sending unpadded password"); |
2791 | send_packet(pwpkt_type, PKT_INT, len, |
2792 | PKT_DATA, password, len, PKT_END); |
32874aea |
2793 | } |
2794 | } else { |
2795 | send_packet(pwpkt_type, PKT_STR, password, PKT_END); |
2796 | } |
2797 | } |
c5e9c988 |
2798 | logevent("Sent password"); |
374330e2 |
2799 | memset(password, 0, strlen(password)); |
fb09bf1c |
2800 | crWaitUntil(ispkt); |
e5574168 |
2801 | if (pktin.type == SSH1_SMSG_FAILURE) { |
32874aea |
2802 | if (flags & FLAG_VERBOSE) |
2803 | c_write_str("Access denied\r\n"); |
c5e9c988 |
2804 | logevent("Authentication refused"); |
e5574168 |
2805 | } else if (pktin.type == SSH1_MSG_DISCONNECT) { |
fb09bf1c |
2806 | logevent("Received disconnect request"); |
32874aea |
2807 | ssh_state = SSH_STATE_CLOSED; |
85ee8208 |
2808 | crReturn(1); |
e5574168 |
2809 | } else if (pktin.type != SSH1_SMSG_SUCCESS) { |
8d5de777 |
2810 | bombout(("Strange packet received, type %d", pktin.type)); |
32874aea |
2811 | crReturn(0); |
374330e2 |
2812 | } |
2813 | } |
2814 | |
c5e9c988 |
2815 | logevent("Authentication successful"); |
2816 | |
fb09bf1c |
2817 | crFinish(1); |
2818 | } |
2819 | |
32874aea |
2820 | void sshfwd_close(struct ssh_channel *c) |
2821 | { |
80e48603 |
2822 | if (c && !c->closes) { |
4ed34d25 |
2823 | /* |
2824 | * If the channel's remoteid is -1, we have sent |
2825 | * CHANNEL_OPEN for this channel, but it hasn't even been |
2826 | * acknowledged by the server. So we must set a close flag |
2827 | * on it now, and then when the server acks the channel |
2828 | * open, we can close it then. |
2829 | */ |
36cac739 |
2830 | if (((int)c->remoteid) != -1) { |
4ed34d25 |
2831 | if (ssh_version == 1) { |
2832 | send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, |
2833 | PKT_END); |
2834 | } else { |
2835 | ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); |
2836 | ssh2_pkt_adduint32(c->remoteid); |
2837 | ssh2_pkt_send(); |
2838 | } |
32874aea |
2839 | } |
2840 | c->closes = 1; |
2841 | if (c->type == CHAN_X11) { |
2842 | c->u.x11.s = NULL; |
d74d141c |
2843 | logevent("Forwarded X11 connection terminated"); |
4ed34d25 |
2844 | } else if (c->type == CHAN_SOCKDATA || |
2845 | c->type == CHAN_SOCKDATA_DORMANT) { |
d74d141c |
2846 | c->u.pfd.s = NULL; |
2847 | logevent("Forwarded port closed"); |
32874aea |
2848 | } |
2849 | } |
2850 | } |
2851 | |
5471d09a |
2852 | int sshfwd_write(struct ssh_channel *c, char *buf, int len) |
32874aea |
2853 | { |
783415f8 |
2854 | if (ssh_version == 1) { |
32874aea |
2855 | send_packet(SSH1_MSG_CHANNEL_DATA, |
2856 | PKT_INT, c->remoteid, |
2857 | PKT_INT, len, PKT_DATA, buf, len, PKT_END); |
5471d09a |
2858 | /* |
2859 | * In SSH1 we can return 0 here - implying that forwarded |
2860 | * connections are never individually throttled - because |
2861 | * the only circumstance that can cause throttling will be |
2862 | * the whole SSH connection backing up, in which case |
2863 | * _everything_ will be throttled as a whole. |
2864 | */ |
2865 | return 0; |
783415f8 |
2866 | } else { |
32874aea |
2867 | ssh2_add_channel_data(c, buf, len); |
5471d09a |
2868 | return ssh2_try_send(c); |
2869 | } |
2870 | } |
2871 | |
2872 | void sshfwd_unthrottle(struct ssh_channel *c, int bufsize) |
2873 | { |
2874 | if (ssh_version == 1) { |
2875 | if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) { |
2876 | c->v.v1.throttling = 0; |
2877 | ssh1_throttle(-1); |
2878 | } |
2879 | } else { |
2880 | ssh2_set_window(c, OUR_V2_WINSIZE - bufsize); |
783415f8 |
2881 | } |
9c964e85 |
2882 | } |
2883 | |
32874aea |
2884 | static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) |
2885 | { |
fb09bf1c |
2886 | crBegin; |
2887 | |
2888 | random_init(); |
2889 | |
e5574168 |
2890 | while (!do_ssh1_login(in, inlen, ispkt)) { |
fb09bf1c |
2891 | crReturnV; |
85ee8208 |
2892 | } |
2893 | if (ssh_state == SSH_STATE_CLOSED) |
32874aea |
2894 | crReturnV; |
fb09bf1c |
2895 | |
979310f1 |
2896 | if (cfg.agentfwd && agent_exists()) { |
32874aea |
2897 | logevent("Requesting agent forwarding"); |
2898 | send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END); |
2899 | do { |
2900 | crReturnV; |
2901 | } while (!ispkt); |
2902 | if (pktin.type != SSH1_SMSG_SUCCESS |
2903 | && pktin.type != SSH1_SMSG_FAILURE) { |
2904 | bombout(("Protocol confusion")); |
2905 | crReturnV; |
2906 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
2907 | logevent("Agent forwarding refused"); |
2908 | } else { |
2909 | logevent("Agent forwarding enabled"); |
db7d555c |
2910 | ssh_agentfwd_enabled = TRUE; |
2911 | } |
dacbd0e8 |
2912 | } |
2913 | |
9c964e85 |
2914 | if (cfg.x11_forward) { |
32874aea |
2915 | char proto[20], data[64]; |
2916 | logevent("Requesting X11 forwarding"); |
2917 | x11_invent_auth(proto, sizeof(proto), data, sizeof(data)); |
2918 | if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) { |
2919 | send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING, |
2920 | PKT_STR, proto, PKT_STR, data, |
2921 | PKT_INT, 0, PKT_END); |
2922 | } else { |
2923 | send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING, |
2924 | PKT_STR, proto, PKT_STR, data, PKT_END); |
2925 | } |
2926 | do { |
2927 | crReturnV; |
2928 | } while (!ispkt); |
2929 | if (pktin.type != SSH1_SMSG_SUCCESS |
2930 | && pktin.type != SSH1_SMSG_FAILURE) { |
2931 | bombout(("Protocol confusion")); |
2932 | crReturnV; |
2933 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
2934 | logevent("X11 forwarding refused"); |
2935 | } else { |
2936 | logevent("X11 forwarding enabled"); |
9c964e85 |
2937 | ssh_X11_fwd_enabled = TRUE; |
2938 | } |
2939 | } |
2940 | |
d74d141c |
2941 | { |
9bf696b1 |
2942 | char type; |
2943 | static char *e; |
d74d141c |
2944 | int n; |
a4fc0d74 |
2945 | int sport,dport,sserv,dserv; |
d74d141c |
2946 | char sports[256], dports[256], host[256]; |
2947 | char buf[1024]; |
a4fc0d74 |
2948 | struct servent *se; |
d74d141c |
2949 | |
bc240b21 |
2950 | ssh_rportfwds = newtree234(ssh_rportcmp_ssh1); |
d74d141c |
2951 | /* Add port forwardings. */ |
2952 | e = cfg.portfwd; |
2953 | while (*e) { |
2954 | type = *e++; |
2955 | n = 0; |
2956 | while (*e && *e != '\t') |
2957 | sports[n++] = *e++; |
2958 | sports[n] = 0; |
2959 | if (*e == '\t') |
2960 | e++; |
2961 | n = 0; |
2962 | while (*e && *e != ':') |
2963 | host[n++] = *e++; |
2964 | host[n] = 0; |
2965 | if (*e == ':') |
2966 | e++; |
2967 | n = 0; |
2968 | while (*e) |
2969 | dports[n++] = *e++; |
2970 | dports[n] = 0; |
2971 | e++; |
2972 | dport = atoi(dports); |
a4fc0d74 |
2973 | dserv = 0; |
2974 | if (dport == 0) { |
2975 | dserv = 1; |
2976 | se = getservbyname(dports, NULL); |
2977 | if (se != NULL) { |
2978 | dport = ntohs(se->s_port); |
2979 | } else { |
2980 | sprintf(buf, |
2981 | "Service lookup failed for destination port \"%s\"", |
2982 | dports); |
2983 | logevent(buf); |
2984 | } |
2985 | } |
d74d141c |
2986 | sport = atoi(sports); |
a4fc0d74 |
2987 | sserv = 0; |
2988 | if (sport == 0) { |
2989 | sserv = 1; |
2990 | se = getservbyname(sports, NULL); |
2991 | if (se != NULL) { |
2992 | sport = ntohs(se->s_port); |
2993 | } else { |
2994 | sprintf(buf, |
2995 | "Service lookup failed for source port \"%s\"", |
2996 | sports); |
2997 | logevent(buf); |
2998 | } |
2999 | } |
d74d141c |
3000 | if (sport && dport) { |
3001 | if (type == 'L') { |
3002 | pfd_addforward(host, dport, sport); |
a4fc0d74 |
3003 | sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to" |
3004 | " %s:%.*s%.*s%d%.*s", |
3005 | sserv ? strlen(sports) : 0, sports, |
3006 | sserv, "(", sport, sserv, ")", |
3007 | host, |
3008 | dserv ? strlen(dports) : 0, dports, |
3009 | dserv, "(", dport, dserv, ")"); |
d74d141c |
3010 | logevent(buf); |
3011 | } else { |
3012 | struct ssh_rportfwd *pf; |
3013 | pf = smalloc(sizeof(*pf)); |
bc240b21 |
3014 | strcpy(pf->dhost, host); |
3015 | pf->dport = dport; |
d74d141c |
3016 | if (add234(ssh_rportfwds, pf) != pf) { |
3017 | sprintf(buf, |
95bc8819 |
3018 | "Duplicate remote port forwarding to %s:%d", |
d74d141c |
3019 | host, dport); |
3020 | logevent(buf); |
bc240b21 |
3021 | sfree(pf); |
d74d141c |
3022 | } else { |
a4fc0d74 |
3023 | sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s" |
3024 | " forward to %s:%.*s%.*s%d%.*s", |
3025 | sserv ? strlen(sports) : 0, sports, |
3026 | sserv, "(", sport, sserv, ")", |
3027 | host, |
3028 | dserv ? strlen(dports) : 0, dports, |
3029 | dserv, "(", dport, dserv, ")"); |
d74d141c |
3030 | logevent(buf); |
3031 | send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST, |
3032 | PKT_INT, sport, |
3033 | PKT_STR, host, |
3034 | PKT_INT, dport, |
3035 | PKT_END); |
9bf696b1 |
3036 | do { |
3037 | crReturnV; |
3038 | } while (!ispkt); |
3039 | if (pktin.type != SSH1_SMSG_SUCCESS |
3040 | && pktin.type != SSH1_SMSG_FAILURE) { |
3041 | bombout(("Protocol confusion")); |
3042 | crReturnV; |
3043 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
3044 | c_write_str("Server refused port forwarding\r\n"); |
3045 | ssh_editing = ssh_echoing = 1; |
3046 | } |
3047 | logevent("Remote port forwarding enabled"); |
d74d141c |
3048 | } |
3049 | } |
3050 | } |
3051 | } |
3052 | } |
3053 | |
fef97f43 |
3054 | if (!cfg.nopty) { |
e5574168 |
3055 | send_packet(SSH1_CMSG_REQUEST_PTY, |
32874aea |
3056 | PKT_STR, cfg.termtype, |
3057 | PKT_INT, rows, PKT_INT, cols, |
3058 | PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END); |
3059 | ssh_state = SSH_STATE_INTERMED; |
3060 | do { |
3061 | crReturnV; |
3062 | } while (!ispkt); |
3063 | if (pktin.type != SSH1_SMSG_SUCCESS |
3064 | && pktin.type != SSH1_SMSG_FAILURE) { |
3065 | bombout(("Protocol confusion")); |
3066 | crReturnV; |
3067 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
3068 | c_write_str("Server refused to allocate pty\r\n"); |
3069 | ssh_editing = ssh_echoing = 1; |
3070 | } |
c5e9c988 |
3071 | logevent("Allocated pty"); |
0965bee0 |
3072 | } else { |
32874aea |
3073 | ssh_editing = ssh_echoing = 1; |
374330e2 |
3074 | } |
3075 | |
4ba9b64b |
3076 | if (cfg.compression) { |
32874aea |
3077 | send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END); |
3078 | do { |
3079 | crReturnV; |
3080 | } while (!ispkt); |
3081 | if (pktin.type != SSH1_SMSG_SUCCESS |
3082 | && pktin.type != SSH1_SMSG_FAILURE) { |
3083 | bombout(("Protocol confusion")); |
3084 | crReturnV; |
3085 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
3086 | c_write_str("Server refused to compress\r\n"); |
3087 | } |
4ba9b64b |
3088 | logevent("Started compression"); |
3089 | ssh1_compressing = TRUE; |
3090 | zlib_compress_init(); |
3091 | zlib_decompress_init(); |
3092 | } |
3093 | |
fd5e5847 |
3094 | /* |
3095 | * Start the shell or command. |
3096 | * |
3097 | * Special case: if the first-choice command is an SSH2 |
3098 | * subsystem (hence not usable here) and the second choice |
3099 | * exists, we fall straight back to that. |
3100 | */ |
3101 | { |
3102 | char *cmd = cfg.remote_cmd_ptr; |
3103 | |
3104 | if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) { |
3105 | cmd = cfg.remote_cmd_ptr2; |
3106 | ssh_fallback_cmd = TRUE; |
3107 | } |
3108 | if (*cmd) |
3109 | send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END); |
3110 | else |
3111 | send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END); |
3112 | logevent("Started session"); |
3113 | } |
374330e2 |
3114 | |
3115 | ssh_state = SSH_STATE_SESSION; |
3116 | if (size_needed) |
3117 | ssh_size(); |
3687d221 |
3118 | if (eof_needed) |
32874aea |
3119 | ssh_special(TS_EOF); |
374330e2 |
3120 | |
760e88b2 |
3121 | ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */ |
8ccc75b0 |
3122 | ssh_send_ok = 1; |
dacbd0e8 |
3123 | ssh_channels = newtree234(ssh_channelcmp); |
374330e2 |
3124 | while (1) { |
3125 | crReturnV; |
3126 | if (ispkt) { |
e5574168 |
3127 | if (pktin.type == SSH1_SMSG_STDOUT_DATA || |
32874aea |
3128 | pktin.type == SSH1_SMSG_STDERR_DATA) { |
fb09bf1c |
3129 | long len = GET_32BIT(pktin.body); |
5471d09a |
3130 | int bufsize = |
3131 | from_backend(pktin.type == SSH1_SMSG_STDERR_DATA, |
3132 | pktin.body + 4, len); |
90347b95 |
3133 | if (!ssh1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) { |
5471d09a |
3134 | ssh1_stdout_throttling = 1; |
3135 | ssh1_throttle(+1); |
3136 | } |
e5574168 |
3137 | } else if (pktin.type == SSH1_MSG_DISCONNECT) { |
32874aea |
3138 | ssh_state = SSH_STATE_CLOSED; |
c5e9c988 |
3139 | logevent("Received disconnect request"); |
32874aea |
3140 | crReturnV; |
3141 | } else if (pktin.type == SSH1_SMSG_X11_OPEN) { |
3142 | /* Remote side is trying to open a channel to talk to our |
3143 | * X-Server. Give them back a local channel number. */ |
3144 | struct ssh_channel *c; |
9c964e85 |
3145 | |
3146 | logevent("Received X11 connect request"); |
3147 | /* Refuse if X11 forwarding is disabled. */ |
3148 | if (!ssh_X11_fwd_enabled) { |
3149 | send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE, |
32874aea |
3150 | PKT_INT, GET_32BIT(pktin.body), PKT_END); |
9c964e85 |
3151 | logevent("Rejected X11 connect request"); |
3152 | } else { |
9c964e85 |
3153 | c = smalloc(sizeof(struct ssh_channel)); |
3154 | |
32874aea |
3155 | if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) { |
3156 | logevent("opening X11 forward connection failed"); |
3157 | sfree(c); |
3158 | send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE, |
3159 | PKT_INT, GET_32BIT(pktin.body), |
3160 | PKT_END); |
9c964e85 |
3161 | } else { |
32874aea |
3162 | logevent |
3163 | ("opening X11 forward connection succeeded"); |
3164 | c->remoteid = GET_32BIT(pktin.body); |
3165 | c->localid = alloc_channel_id(); |
3166 | c->closes = 0; |
5471d09a |
3167 | c->v.v1.throttling = 0; |
32874aea |
3168 | c->type = CHAN_X11; /* identify channel type */ |
3169 | add234(ssh_channels, c); |
3170 | send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, |
3171 | PKT_INT, c->remoteid, PKT_INT, |
3172 | c->localid, PKT_END); |
3173 | logevent("Opened X11 forward channel"); |
9c964e85 |
3174 | } |
3175 | } |
32874aea |
3176 | } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) { |
3177 | /* Remote side is trying to open a channel to talk to our |
3178 | * agent. Give them back a local channel number. */ |
3179 | struct ssh_channel *c; |
db7d555c |
3180 | |
3181 | /* Refuse if agent forwarding is disabled. */ |
3182 | if (!ssh_agentfwd_enabled) { |
3183 | send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE, |
32874aea |
3184 | PKT_INT, GET_32BIT(pktin.body), PKT_END); |
db7d555c |
3185 | } else { |
dcbde236 |
3186 | c = smalloc(sizeof(struct ssh_channel)); |
db7d555c |
3187 | c->remoteid = GET_32BIT(pktin.body); |
d2371c81 |
3188 | c->localid = alloc_channel_id(); |
db7d555c |
3189 | c->closes = 0; |
5471d09a |
3190 | c->v.v1.throttling = 0; |
32874aea |
3191 | c->type = CHAN_AGENT; /* identify channel type */ |
db7d555c |
3192 | c->u.a.lensofar = 0; |
3193 | add234(ssh_channels, c); |
3194 | send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, |
3195 | PKT_INT, c->remoteid, PKT_INT, c->localid, |
3196 | PKT_END); |
3197 | } |
d74d141c |
3198 | } else if (pktin.type == SSH1_MSG_PORT_OPEN) { |
3199 | /* Remote side is trying to open a channel to talk to a |
3200 | * forwarded port. Give them back a local channel number. */ |
3201 | struct ssh_channel *c; |
3202 | struct ssh_rportfwd pf; |
3203 | int hostsize, port; |
3204 | char host[256], buf[1024]; |
3205 | char *p, *h, *e; |
3206 | c = smalloc(sizeof(struct ssh_channel)); |
3207 | |
3208 | hostsize = GET_32BIT(pktin.body+4); |
3209 | for(h = host, p = pktin.body+8; hostsize != 0; hostsize--) { |
3210 | if (h+1 < host+sizeof(host)) |
3211 | *h++ = *p; |
95bc8819 |
3212 | p++; |
d74d141c |
3213 | } |
3214 | *h = 0; |
3215 | port = GET_32BIT(p); |
3216 | |
bc240b21 |
3217 | strcpy(pf.dhost, host); |
3218 | pf.dport = port; |
d74d141c |
3219 | |
3220 | if (find234(ssh_rportfwds, &pf, NULL) == NULL) { |
3221 | sprintf(buf, "Rejected remote port open request for %s:%d", |
3222 | host, port); |
3223 | logevent(buf); |
3224 | send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE, |
3225 | PKT_INT, GET_32BIT(pktin.body), PKT_END); |
3226 | } else { |
3227 | sprintf(buf, "Received remote port open request for %s:%d", |
3228 | host, port); |
3229 | logevent(buf); |
3230 | e = pfd_newconnect(&c->u.pfd.s, host, port, c); |
3231 | if (e != NULL) { |
3232 | char buf[256]; |
3233 | sprintf(buf, "Port open failed: %s", e); |
3234 | logevent(buf); |
3235 | sfree(c); |
3236 | send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE, |
3237 | PKT_INT, GET_32BIT(pktin.body), |
3238 | PKT_END); |
3239 | } else { |
3240 | c->remoteid = GET_32BIT(pktin.body); |
3241 | c->localid = alloc_channel_id(); |
3242 | c->closes = 0; |
5471d09a |
3243 | c->v.v1.throttling = 0; |
d74d141c |
3244 | c->type = CHAN_SOCKDATA; /* identify channel type */ |
3245 | add234(ssh_channels, c); |
3246 | send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, |
3247 | PKT_INT, c->remoteid, PKT_INT, |
3248 | c->localid, PKT_END); |
3249 | logevent("Forwarded port opened successfully"); |
3250 | } |
3251 | } |
3252 | |
3253 | } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) { |
bc240b21 |
3254 | unsigned int remoteid = GET_32BIT(pktin.body); |
3255 | unsigned int localid = GET_32BIT(pktin.body+4); |
3256 | struct ssh_channel *c; |
3257 | |
3258 | c = find234(ssh_channels, &remoteid, ssh_channelfind); |
3259 | if (c && c->type == CHAN_SOCKDATA_DORMANT) { |
3260 | c->remoteid = localid; |
3261 | c->type = CHAN_SOCKDATA; |
7781f316 |
3262 | c->v.v1.throttling = 0; |
bc240b21 |
3263 | pfd_confirm(c->u.pfd.s); |
3264 | } |
d74d141c |
3265 | |
4ed34d25 |
3266 | if (c && c->closes) { |
3267 | /* |
3268 | * We have a pending close on this channel, |
3269 | * which we decided on before the server acked |
3270 | * the channel open. So now we know the |
3271 | * remoteid, we can close it again. |
3272 | */ |
3273 | send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, |
3274 | PKT_END); |
3275 | } |
3276 | |
724cface |
3277 | } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) { |
3278 | unsigned int remoteid = GET_32BIT(pktin.body); |
3279 | unsigned int localid = GET_32BIT(pktin.body+4); |
3280 | struct ssh_channel *c; |
3281 | |
3282 | c = find234(ssh_channels, &remoteid, ssh_channelfind); |
3283 | if (c && c->type == CHAN_SOCKDATA_DORMANT) { |
3284 | logevent("Forwarded connection refused by server"); |
3285 | pfd_close(c->u.pfd.s); |
3286 | del234(ssh_channels, c); |
3287 | sfree(c); |
3288 | } |
3289 | |
db7d555c |
3290 | } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE || |
3291 | pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) { |
32874aea |
3292 | /* Remote side closes a channel. */ |
3293 | unsigned i = GET_32BIT(pktin.body); |
3294 | struct ssh_channel *c; |
3295 | c = find234(ssh_channels, &i, ssh_channelfind); |
3296 | if (c) { |
3297 | int closetype; |
3298 | closetype = |
3299 | (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2); |
3300 | if (!(c->closes & closetype)) |
3301 | send_packet(pktin.type, PKT_INT, c->remoteid, |
3302 | PKT_END); |
783415f8 |
3303 | if ((c->closes == 0) && (c->type == CHAN_X11)) { |
d74d141c |
3304 | logevent("Forwarded X11 connection terminated"); |
9c964e85 |
3305 | assert(c->u.x11.s != NULL); |
3306 | x11_close(c->u.x11.s); |
3307 | c->u.x11.s = NULL; |
3308 | } |
d74d141c |
3309 | if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) { |
3310 | logevent("Forwarded port closed"); |
3311 | assert(c->u.pfd.s != NULL); |
3312 | pfd_close(c->u.pfd.s); |
3313 | c->u.pfd.s = NULL; |
3314 | } |
32874aea |
3315 | c->closes |= closetype; |
3316 | if (c->closes == 3) { |
3317 | del234(ssh_channels, c); |
3318 | sfree(c); |
3319 | } |
3320 | } |
3321 | } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) { |
3322 | /* Data sent down one of our channels. */ |
3323 | int i = GET_32BIT(pktin.body); |
3324 | int len = GET_32BIT(pktin.body + 4); |
3325 | unsigned char *p = pktin.body + 8; |
3326 | struct ssh_channel *c; |
3327 | c = find234(ssh_channels, &i, ssh_channelfind); |
3328 | if (c) { |
5471d09a |
3329 | int bufsize; |
32874aea |
3330 | switch (c->type) { |
3331 | case CHAN_X11: |
5471d09a |
3332 | bufsize = x11_send(c->u.x11.s, p, len); |
9c964e85 |
3333 | break; |
d74d141c |
3334 | case CHAN_SOCKDATA: |
5471d09a |
3335 | bufsize = pfd_send(c->u.pfd.s, p, len); |
bc240b21 |
3336 | break; |
32874aea |
3337 | case CHAN_AGENT: |
3338 | /* Data for an agent message. Buffer it. */ |
3339 | while (len > 0) { |
3340 | if (c->u.a.lensofar < 4) { |
3341 | int l = min(4 - c->u.a.lensofar, len); |
3342 | memcpy(c->u.a.msglen + c->u.a.lensofar, p, |
3343 | l); |
3344 | p += l; |
3345 | len -= l; |
3346 | c->u.a.lensofar += l; |
3347 | } |
3348 | if (c->u.a.lensofar == 4) { |
3349 | c->u.a.totallen = |
3350 | 4 + GET_32BIT(c->u.a.msglen); |
3351 | c->u.a.message = smalloc(c->u.a.totallen); |
3352 | memcpy(c->u.a.message, c->u.a.msglen, 4); |
3353 | } |
3354 | if (c->u.a.lensofar >= 4 && len > 0) { |
3355 | int l = |
3356 | min(c->u.a.totallen - c->u.a.lensofar, |
3357 | len); |
3358 | memcpy(c->u.a.message + c->u.a.lensofar, p, |
3359 | l); |
3360 | p += l; |
3361 | len -= l; |
3362 | c->u.a.lensofar += l; |
3363 | } |
3364 | if (c->u.a.lensofar == c->u.a.totallen) { |
3365 | void *reply, *sentreply; |
3366 | int replylen; |
3367 | agent_query(c->u.a.message, |
3368 | c->u.a.totallen, &reply, |
3369 | &replylen); |
3370 | if (reply) |
3371 | sentreply = reply; |
3372 | else { |
3373 | /* Fake SSH_AGENT_FAILURE. */ |
3374 | sentreply = "\0\0\0\1\5"; |
3375 | replylen = 5; |
3376 | } |
3377 | send_packet(SSH1_MSG_CHANNEL_DATA, |
3378 | PKT_INT, c->remoteid, |
3379 | PKT_INT, replylen, |
3380 | PKT_DATA, sentreply, replylen, |
3381 | PKT_END); |
3382 | if (reply) |
3383 | sfree(reply); |
3384 | sfree(c->u.a.message); |
3385 | c->u.a.lensofar = 0; |
3386 | } |
3387 | } |
5471d09a |
3388 | bufsize = 0; /* agent channels never back up */ |
32874aea |
3389 | break; |
3390 | } |
90347b95 |
3391 | if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) { |
5471d09a |
3392 | c->v.v1.throttling = 1; |
3393 | ssh1_throttle(+1); |
3394 | } |
32874aea |
3395 | } |
e5574168 |
3396 | } else if (pktin.type == SSH1_SMSG_SUCCESS) { |
972a41c8 |
3397 | /* may be from EXEC_SHELL on some servers */ |
e5574168 |
3398 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
972a41c8 |
3399 | /* may be from EXEC_SHELL on some servers |
374330e2 |
3400 | * if no pty is available or in other odd cases. Ignore */ |
e5574168 |
3401 | } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) { |
d8d6c7e5 |
3402 | char buf[100]; |
3403 | ssh_exitcode = GET_32BIT(pktin.body); |
3404 | sprintf(buf, "Server sent command exit status %d", |
3405 | ssh_exitcode); |
3406 | logevent(buf); |
e5574168 |
3407 | send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END); |
4252c9cc |
3408 | /* |
3409 | * In case `helpful' firewalls or proxies tack |
3410 | * extra human-readable text on the end of the |
3411 | * session which we might mistake for another |
3412 | * encrypted packet, we close the session once |
3413 | * we've sent EXIT_CONFIRMATION. |
3414 | */ |
3415 | ssh_state = SSH_STATE_CLOSED; |
3416 | crReturnV; |
374330e2 |
3417 | } else { |
8d5de777 |
3418 | bombout(("Strange packet received: type %d", pktin.type)); |
32874aea |
3419 | crReturnV; |
374330e2 |
3420 | } |
3421 | } else { |
8df7a775 |
3422 | while (inlen > 0) { |
3423 | int len = min(inlen, 512); |
3424 | send_packet(SSH1_CMSG_STDIN_DATA, |
3425 | PKT_INT, len, PKT_DATA, in, len, PKT_END); |
3426 | in += len; |
3427 | inlen -= len; |
3428 | } |
374330e2 |
3429 | } |
3430 | } |
3431 | |
3432 | crFinishV; |
3433 | } |
3434 | |
3435 | /* |
e5574168 |
3436 | * Utility routine for decoding comma-separated strings in KEXINIT. |
3437 | */ |
32874aea |
3438 | static int in_commasep_string(char *needle, char *haystack, int haylen) |
3439 | { |
e5574168 |
3440 | int needlen = strlen(needle); |
3441 | while (1) { |
32874aea |
3442 | /* |
3443 | * Is it at the start of the string? |
3444 | */ |
3445 | if (haylen >= needlen && /* haystack is long enough */ |
3446 | !memcmp(needle, haystack, needlen) && /* initial match */ |
3447 | (haylen == needlen || haystack[needlen] == ',') |
3448 | /* either , or EOS follows */ |
3449 | ) |
3450 | return 1; |
3451 | /* |
3452 | * If not, search for the next comma and resume after that. |
3453 | * If no comma found, terminate. |
3454 | */ |
3455 | while (haylen > 0 && *haystack != ',') |
3456 | haylen--, haystack++; |
3457 | if (haylen == 0) |
3458 | return 0; |
3459 | haylen--, haystack++; /* skip over comma itself */ |
e5574168 |
3460 | } |
3461 | } |
3462 | |
3463 | /* |
d39f364a |
3464 | * SSH2 key creation method. |
3465 | */ |
32874aea |
3466 | static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr, |
3467 | char *keyspace) |
3468 | { |
d39f364a |
3469 | SHA_State s; |
3470 | /* First 20 bytes. */ |
3471 | SHA_Init(&s); |
3472 | sha_mpint(&s, K); |
3473 | SHA_Bytes(&s, H, 20); |
3474 | SHA_Bytes(&s, &chr, 1); |
5e0d7cb8 |
3475 | SHA_Bytes(&s, sessid, 20); |
d39f364a |
3476 | SHA_Final(&s, keyspace); |
3477 | /* Next 20 bytes. */ |
3478 | SHA_Init(&s); |
3479 | sha_mpint(&s, K); |
3480 | SHA_Bytes(&s, H, 20); |
3481 | SHA_Bytes(&s, keyspace, 20); |
32874aea |
3482 | SHA_Final(&s, keyspace + 20); |
d39f364a |
3483 | } |
3484 | |
3485 | /* |
7cca0d81 |
3486 | * Handle the SSH2 transport layer. |
e5574168 |
3487 | */ |
7cca0d81 |
3488 | static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt) |
e5574168 |
3489 | { |
ca20bfcf |
3490 | static int i, j, len, nbits, pbits, warn; |
e5574168 |
3491 | static char *str; |
a92dd380 |
3492 | static Bignum p, g, e, f, K; |
3493 | static int kex_init_value, kex_reply_value; |
7591b9ff |
3494 | static const struct ssh_mac **maclist; |
8b2715b2 |
3495 | static int nmacs; |
0a3f1d48 |
3496 | static const struct ssh2_cipher *cscipher_tobe = NULL; |
3497 | static const struct ssh2_cipher *sccipher_tobe = NULL; |
57476f6b |
3498 | static const struct ssh_mac *csmac_tobe = NULL; |
3499 | static const struct ssh_mac *scmac_tobe = NULL; |
3500 | static const struct ssh_compress *cscomp_tobe = NULL; |
3501 | static const struct ssh_compress *sccomp_tobe = NULL; |
d5859615 |
3502 | static char *hostkeydata, *sigdata, *keystr, *fingerprint; |
e5574168 |
3503 | static int hostkeylen, siglen; |
e055a386 |
3504 | static void *hkey; /* actual host key */ |
e5574168 |
3505 | static unsigned char exchange_hash[20]; |
d39f364a |
3506 | static unsigned char keyspace[40]; |
ca20bfcf |
3507 | static int n_preferred_ciphers; |
3508 | static const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX]; |
4ba9b64b |
3509 | static const struct ssh_compress *preferred_comp; |
087abe1a |
3510 | static int cipherstr_started; |
0db56f73 |
3511 | static int first_kex; |
e5574168 |
3512 | |
3513 | crBegin; |
7cca0d81 |
3514 | random_init(); |
0db56f73 |
3515 | first_kex = 1; |
e5574168 |
3516 | |
5e8358ad |
3517 | /* |
ca20bfcf |
3518 | * Set up the preferred ciphers. (NULL => warn below here) |
5e8358ad |
3519 | */ |
ca20bfcf |
3520 | n_preferred_ciphers = 0; |
3521 | for (i = 0; i < CIPHER_MAX; i++) { |
3522 | switch (cfg.ssh_cipherlist[i]) { |
3523 | case CIPHER_BLOWFISH: |
3524 | preferred_ciphers[n_preferred_ciphers] = &ssh2_blowfish; |
3525 | n_preferred_ciphers++; |
3526 | break; |
3527 | case CIPHER_DES: |
087abe1a |
3528 | if (cfg.ssh2_des_cbc) { |
3529 | preferred_ciphers[n_preferred_ciphers] = &ssh2_des; |
3530 | n_preferred_ciphers++; |
3531 | } |
ca20bfcf |
3532 | break; |
3533 | case CIPHER_3DES: |
3534 | preferred_ciphers[n_preferred_ciphers] = &ssh2_3des; |
3535 | n_preferred_ciphers++; |
3536 | break; |
3537 | case CIPHER_AES: |
3538 | preferred_ciphers[n_preferred_ciphers] = &ssh2_aes; |
3539 | n_preferred_ciphers++; |
3540 | break; |
3541 | case CIPHER_WARN: |
3542 | /* Flag for later. Don't bother if it's the last in |
3543 | * the list. */ |
3544 | if (i < CIPHER_MAX - 1) { |
3545 | preferred_ciphers[n_preferred_ciphers] = NULL; |
3546 | n_preferred_ciphers++; |
3547 | } |
3548 | break; |
3549 | } |
5e8358ad |
3550 | } |
ca20bfcf |
3551 | |
3552 | /* |
3553 | * Set up preferred compression. |
3554 | */ |
4ba9b64b |
3555 | if (cfg.compression) |
3556 | preferred_comp = &ssh_zlib; |
3557 | else |
3558 | preferred_comp = &ssh_comp_none; |
5e8358ad |
3559 | |
7591b9ff |
3560 | /* |
3561 | * Be prepared to work around the buggy MAC problem. |
3562 | */ |
7d503c31 |
3563 | if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC)) |
32874aea |
3564 | maclist = buggymacs, nmacs = lenof(buggymacs); |
7591b9ff |
3565 | else |
32874aea |
3566 | maclist = macs, nmacs = lenof(macs); |
7591b9ff |
3567 | |
32874aea |
3568 | begin_key_exchange: |
e5574168 |
3569 | /* |
3570 | * Construct and send our key exchange packet. |
3571 | */ |
3572 | ssh2_pkt_init(SSH2_MSG_KEXINIT); |
3573 | for (i = 0; i < 16; i++) |
32874aea |
3574 | ssh2_pkt_addbyte((unsigned char) random_byte()); |
e5574168 |
3575 | /* List key exchange algorithms. */ |
3576 | ssh2_pkt_addstring_start(); |
3577 | for (i = 0; i < lenof(kex_algs); i++) { |
32874aea |
3578 | ssh2_pkt_addstring_str(kex_algs[i]->name); |
3579 | if (i < lenof(kex_algs) - 1) |
3580 | ssh2_pkt_addstring_str(","); |
e5574168 |
3581 | } |
3582 | /* List server host key algorithms. */ |
3583 | ssh2_pkt_addstring_start(); |
3584 | for (i = 0; i < lenof(hostkey_algs); i++) { |
32874aea |
3585 | ssh2_pkt_addstring_str(hostkey_algs[i]->name); |
3586 | if (i < lenof(hostkey_algs) - 1) |
3587 | ssh2_pkt_addstring_str(","); |
e5574168 |
3588 | } |
3589 | /* List client->server encryption algorithms. */ |
3590 | ssh2_pkt_addstring_start(); |
087abe1a |
3591 | cipherstr_started = 0; |
ca20bfcf |
3592 | for (i = 0; i < n_preferred_ciphers; i++) { |
3593 | const struct ssh2_ciphers *c = preferred_ciphers[i]; |
3594 | if (!c) continue; /* warning flag */ |
32874aea |
3595 | for (j = 0; j < c->nciphers; j++) { |
087abe1a |
3596 | if (cipherstr_started) |
32874aea |
3597 | ssh2_pkt_addstring_str(","); |
087abe1a |
3598 | ssh2_pkt_addstring_str(c->list[j]->name); |
3599 | cipherstr_started = 1; |
32874aea |
3600 | } |
e5574168 |
3601 | } |
3602 | /* List server->client encryption algorithms. */ |
3603 | ssh2_pkt_addstring_start(); |
087abe1a |
3604 | cipherstr_started = 0; |
ca20bfcf |
3605 | for (i = 0; i < n_preferred_ciphers; i++) { |
3606 | const struct ssh2_ciphers *c = preferred_ciphers[i]; |
3607 | if (!c) continue; /* warning flag */ |
32874aea |
3608 | for (j = 0; j < c->nciphers; j++) { |
087abe1a |
3609 | if (cipherstr_started) |
32874aea |
3610 | ssh2_pkt_addstring_str(","); |
087abe1a |
3611 | ssh2_pkt_addstring_str(c->list[j]->name); |
3612 | cipherstr_started = 1; |
32874aea |
3613 | } |
e5574168 |
3614 | } |
3615 | /* List client->server MAC algorithms. */ |
3616 | ssh2_pkt_addstring_start(); |
8b2715b2 |
3617 | for (i = 0; i < nmacs; i++) { |
32874aea |
3618 | ssh2_pkt_addstring_str(maclist[i]->name); |
3619 | if (i < nmacs - 1) |
3620 | ssh2_pkt_addstring_str(","); |
e5574168 |
3621 | } |
3622 | /* List server->client MAC algorithms. */ |
3623 | ssh2_pkt_addstring_start(); |
8b2715b2 |
3624 | for (i = 0; i < nmacs; i++) { |
32874aea |
3625 | ssh2_pkt_addstring_str(maclist[i]->name); |
3626 | if (i < nmacs - 1) |
3627 | ssh2_pkt_addstring_str(","); |
e5574168 |
3628 | } |
3629 | /* List client->server compression algorithms. */ |
3630 | ssh2_pkt_addstring_start(); |
32874aea |
3631 | for (i = 0; i < lenof(compressions) + 1; i++) { |
3632 | const struct ssh_compress *c = |
3633 | i == 0 ? preferred_comp : compressions[i - 1]; |
3634 | ssh2_pkt_addstring_str(c->name); |
3635 | if (i < lenof(compressions)) |
3636 | ssh2_pkt_addstring_str(","); |
e5574168 |
3637 | } |
3638 | /* List server->client compression algorithms. */ |
3639 | ssh2_pkt_addstring_start(); |
32874aea |
3640 | for (i = 0; i < lenof(compressions) + 1; i++) { |
3641 | const struct ssh_compress *c = |
3642 | i == 0 ? preferred_comp : compressions[i - 1]; |
3643 | ssh2_pkt_addstring_str(c->name); |
3644 | if (i < lenof(compressions)) |
3645 | ssh2_pkt_addstring_str(","); |
e5574168 |
3646 | } |
3647 | /* List client->server languages. Empty list. */ |
3648 | ssh2_pkt_addstring_start(); |
3649 | /* List server->client languages. Empty list. */ |
3650 | ssh2_pkt_addstring_start(); |
3651 | /* First KEX packet does _not_ follow, because we're not that brave. */ |
3652 | ssh2_pkt_addbool(FALSE); |
3653 | /* Reserved. */ |
3654 | ssh2_pkt_adduint32(0); |
0db56f73 |
3655 | |
3656 | exhash = exhashbase; |
32874aea |
3657 | sha_string(&exhash, pktout.data + 5, pktout.length - 5); |
0db56f73 |
3658 | |
e5574168 |
3659 | ssh2_pkt_send(); |
3660 | |
32874aea |
3661 | if (!ispkt) |
3662 | crWaitUntil(ispkt); |
3663 | sha_string(&exhash, pktin.data + 5, pktin.length - 5); |
e5574168 |
3664 | |
3665 | /* |
3666 | * Now examine the other side's KEXINIT to see what we're up |
3667 | * to. |
3668 | */ |
7cca0d81 |
3669 | if (pktin.type != SSH2_MSG_KEXINIT) { |
32874aea |
3670 | bombout(("expected key exchange packet from server")); |
3671 | crReturn(0); |
7cca0d81 |
3672 | } |
32874aea |
3673 | kex = NULL; |
3674 | hostkey = NULL; |
3675 | cscipher_tobe = NULL; |
3676 | sccipher_tobe = NULL; |
3677 | csmac_tobe = NULL; |
3678 | scmac_tobe = NULL; |
3679 | cscomp_tobe = NULL; |
3680 | sccomp_tobe = NULL; |
3681 | pktin.savedpos += 16; /* skip garbage cookie */ |
e5574168 |
3682 | ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */ |
3683 | for (i = 0; i < lenof(kex_algs); i++) { |
32874aea |
3684 | if (in_commasep_string(kex_algs[i]->name, str, len)) { |
3685 | kex = kex_algs[i]; |
3686 | break; |
3687 | } |
e5574168 |
3688 | } |
3689 | ssh2_pkt_getstring(&str, &len); /* host key algorithms */ |
3690 | for (i = 0; i < lenof(hostkey_algs); i++) { |
32874aea |
3691 | if (in_commasep_string(hostkey_algs[i]->name, str, len)) { |
3692 | hostkey = hostkey_algs[i]; |
3693 | break; |
3694 | } |
e5574168 |
3695 | } |
3696 | ssh2_pkt_getstring(&str, &len); /* client->server cipher */ |
ca20bfcf |
3697 | warn = 0; |
3698 | for (i = 0; i < n_preferred_ciphers; i++) { |
3699 | const struct ssh2_ciphers *c = preferred_ciphers[i]; |
3700 | if (!c) { |
3701 | warn = 1; |
3702 | } else { |
3703 | for (j = 0; j < c->nciphers; j++) { |
3704 | if (in_commasep_string(c->list[j]->name, str, len)) { |
3705 | cscipher_tobe = c->list[j]; |
3706 | break; |
3707 | } |
32874aea |
3708 | } |
3709 | } |
ca20bfcf |
3710 | if (cscipher_tobe) { |
3711 | if (warn) |
3712 | askcipher(cscipher_tobe->name, 1); |
32874aea |
3713 | break; |
ca20bfcf |
3714 | } |
e5574168 |
3715 | } |
0ef8f407 |
3716 | if (!cscipher_tobe) { |
3717 | bombout(("Couldn't agree a client-to-server cipher (available: %s)", str)); |
3718 | crReturn(0); |
3719 | } |
3720 | |
e5574168 |
3721 | ssh2_pkt_getstring(&str, &len); /* server->client cipher */ |
ca20bfcf |
3722 | warn = 0; |
3723 | for (i = 0; i < n_preferred_ciphers; i++) { |
3724 | const struct ssh2_ciphers *c = preferred_ciphers[i]; |
3725 | if (!c) { |
3726 | warn = 1; |
3727 | } else { |
3728 | for (j = 0; j < c->nciphers; j++) { |
3729 | if (in_commasep_string(c->list[j]->name, str, len)) { |
3730 | sccipher_tobe = c->list[j]; |
3731 | break; |
3732 | } |
32874aea |
3733 | } |
3734 | } |
ca20bfcf |
3735 | if (sccipher_tobe) { |
3736 | if (warn) |
3737 | askcipher(sccipher_tobe->name, 2); |
32874aea |
3738 | break; |
ca20bfcf |
3739 | } |
e5574168 |
3740 | } |
0ef8f407 |
3741 | if (!sccipher_tobe) { |
3742 | bombout(("Couldn't agree a server-to-client cipher (available: %s)", str)); |
3743 | crReturn(0); |
3744 | } |
3745 | |
e5574168 |
3746 | ssh2_pkt_getstring(&str, &len); /* client->server mac */ |
8b2715b2 |
3747 | for (i = 0; i < nmacs; i++) { |
32874aea |
3748 | if (in_commasep_string(maclist[i]->name, str, len)) { |
3749 | csmac_tobe = maclist[i]; |
3750 | break; |
3751 | } |
e5574168 |
3752 | } |
3753 | ssh2_pkt_getstring(&str, &len); /* server->client mac */ |
8b2715b2 |
3754 | for (i = 0; i < nmacs; i++) { |
32874aea |
3755 | if (in_commasep_string(maclist[i]->name, str, len)) { |
3756 | scmac_tobe = maclist[i]; |
3757 | break; |
3758 | } |
e5574168 |
3759 | } |
3760 | ssh2_pkt_getstring(&str, &len); /* client->server compression */ |
32874aea |
3761 | for (i = 0; i < lenof(compressions) + 1; i++) { |
3762 | const struct ssh_compress *c = |
3763 | i == 0 ? preferred_comp : compressions[i - 1]; |
3764 | if (in_commasep_string(c->name, str, len)) { |
3765 | cscomp_tobe = c; |
3766 | break; |
3767 | } |
e5574168 |
3768 | } |
3769 | ssh2_pkt_getstring(&str, &len); /* server->client compression */ |
32874aea |
3770 | for (i = 0; i < lenof(compressions) + 1; i++) { |
3771 | const struct ssh_compress *c = |
3772 | i == 0 ? preferred_comp : compressions[i - 1]; |
3773 | if (in_commasep_string(c->name, str, len)) { |
3774 | sccomp_tobe = c; |
3775 | break; |
3776 | } |
e5574168 |
3777 | } |
e5574168 |
3778 | |
3779 | /* |
7bd5a860 |
3780 | * Work out the number of bits of key we will need from the key |
3781 | * exchange. We start with the maximum key length of either |
3782 | * cipher... |
3783 | */ |
3784 | { |
32874aea |
3785 | int csbits, scbits; |
7bd5a860 |
3786 | |
3787 | csbits = cscipher_tobe->keylen; |
3788 | scbits = sccipher_tobe->keylen; |
3789 | nbits = (csbits > scbits ? csbits : scbits); |
3790 | } |
3791 | /* The keys only have 160-bit entropy, since they're based on |
3792 | * a SHA-1 hash. So cap the key size at 160 bits. */ |
32874aea |
3793 | if (nbits > 160) |
3794 | nbits = 160; |
7bd5a860 |
3795 | |
3796 | /* |
a92dd380 |
3797 | * If we're doing Diffie-Hellman group exchange, start by |
3798 | * requesting a group. |
e5574168 |
3799 | */ |
a92dd380 |
3800 | if (kex == &ssh_diffiehellman_gex) { |
32874aea |
3801 | logevent("Doing Diffie-Hellman group exchange"); |
00db133f |
3802 | ssh_pkt_ctx |= SSH2_PKTCTX_DHGEX; |
32874aea |
3803 | /* |
3804 | * Work out how big a DH group we will need to allow that |
3805 | * much data. |
7bd5a860 |
3806 | */ |
32874aea |
3807 | pbits = 512 << ((nbits - 1) / 64); |
3808 | ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST); |
3809 | ssh2_pkt_adduint32(pbits); |
3810 | ssh2_pkt_send(); |
3811 | |
3812 | crWaitUntil(ispkt); |
3813 | if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) { |
3814 | bombout(("expected key exchange group packet from server")); |
3815 | crReturn(0); |
3816 | } |
3817 | p = ssh2_pkt_getmp(); |
3818 | g = ssh2_pkt_getmp(); |
3819 | dh_setup_group(p, g); |
3820 | kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT; |
3821 | kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY; |
a92dd380 |
3822 | } else { |
00db133f |
3823 | ssh_pkt_ctx |= SSH2_PKTCTX_DHGROUP1; |
32874aea |
3824 | dh_setup_group1(); |
3825 | kex_init_value = SSH2_MSG_KEXDH_INIT; |
3826 | kex_reply_value = SSH2_MSG_KEXDH_REPLY; |
8d5de777 |
3827 | } |
e5574168 |
3828 | |
a92dd380 |
3829 | logevent("Doing Diffie-Hellman key exchange"); |
e5574168 |
3830 | /* |
a92dd380 |
3831 | * Now generate and send e for Diffie-Hellman. |
e5574168 |
3832 | */ |
32874aea |
3833 | e = dh_create_e(nbits * 2); |
a92dd380 |
3834 | ssh2_pkt_init(kex_init_value); |
e5574168 |
3835 | ssh2_pkt_addmp(e); |
3836 | ssh2_pkt_send(); |
3837 | |
3838 | crWaitUntil(ispkt); |
a92dd380 |
3839 | if (pktin.type != kex_reply_value) { |
32874aea |
3840 | bombout(("expected key exchange reply packet from server")); |
3841 | crReturn(0); |
7cca0d81 |
3842 | } |
e5574168 |
3843 | ssh2_pkt_getstring(&hostkeydata, &hostkeylen); |
3844 | f = ssh2_pkt_getmp(); |
e5574168 |
3845 | ssh2_pkt_getstring(&sigdata, &siglen); |
3846 | |
3847 | K = dh_find_K(f); |
e5574168 |
3848 | |
3849 | sha_string(&exhash, hostkeydata, hostkeylen); |
a92dd380 |
3850 | if (kex == &ssh_diffiehellman_gex) { |
32874aea |
3851 | sha_uint32(&exhash, pbits); |
3852 | sha_mpint(&exhash, p); |
3853 | sha_mpint(&exhash, g); |
a92dd380 |
3854 | } |
e5574168 |
3855 | sha_mpint(&exhash, e); |
3856 | sha_mpint(&exhash, f); |
3857 | sha_mpint(&exhash, K); |
3858 | SHA_Final(&exhash, exchange_hash); |
3859 | |
3709bfe9 |
3860 | dh_cleanup(); |
3861 | |
7cca0d81 |
3862 | #if 0 |
765c4200 |
3863 | debug(("Exchange hash is:\n")); |
3864 | dmemdump(exchange_hash, 20); |
7cca0d81 |
3865 | #endif |
3866 | |
e055a386 |
3867 | hkey = hostkey->newkey(hostkeydata, hostkeylen); |
f7259d10 |
3868 | if (!hkey || |
3869 | !hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) { |
3870 | bombout(("Server's host key did not match the signature supplied")); |
32874aea |
3871 | crReturn(0); |
8d5de777 |
3872 | } |
e5574168 |
3873 | |
3874 | /* |
7cca0d81 |
3875 | * Authenticate remote host: verify host key. (We've already |
3876 | * checked the signature of the exchange hash.) |
e5574168 |
3877 | */ |
e055a386 |
3878 | keystr = hostkey->fmtkey(hkey); |
3879 | fingerprint = hostkey->fingerprint(hkey); |
d4857987 |
3880 | verify_ssh_host_key(savedhost, savedport, hostkey->keytype, |
32874aea |
3881 | keystr, fingerprint); |
3882 | if (first_kex) { /* don't bother logging this in rekeys */ |
5e0d7cb8 |
3883 | logevent("Host key fingerprint is:"); |
3884 | logevent(fingerprint); |
3885 | } |
dcbde236 |
3886 | sfree(fingerprint); |
3887 | sfree(keystr); |
e055a386 |
3888 | hostkey->freekey(hkey); |
d39f364a |
3889 | |
3890 | /* |
7cca0d81 |
3891 | * Send SSH2_MSG_NEWKEYS. |
d39f364a |
3892 | */ |
3893 | ssh2_pkt_init(SSH2_MSG_NEWKEYS); |
3894 | ssh2_pkt_send(); |
d39f364a |
3895 | |
3896 | /* |
8406eaf9 |
3897 | * Expect SSH2_MSG_NEWKEYS from server. |
3898 | */ |
3899 | crWaitUntil(ispkt); |
3900 | if (pktin.type != SSH2_MSG_NEWKEYS) { |
3901 | bombout(("expected new-keys packet from server")); |
3902 | crReturn(0); |
3903 | } |
3904 | |
3905 | /* |
d39f364a |
3906 | * Create and initialise session keys. |
3907 | */ |
3908 | cscipher = cscipher_tobe; |
3909 | sccipher = sccipher_tobe; |
3910 | csmac = csmac_tobe; |
3911 | scmac = scmac_tobe; |
3912 | cscomp = cscomp_tobe; |
3913 | sccomp = sccomp_tobe; |
4ba9b64b |
3914 | cscomp->compress_init(); |
3915 | sccomp->decompress_init(); |
d39f364a |
3916 | /* |
5e0d7cb8 |
3917 | * Set IVs after keys. Here we use the exchange hash from the |
3918 | * _first_ key exchange. |
d39f364a |
3919 | */ |
5e0d7cb8 |
3920 | if (first_kex) |
65a22376 |
3921 | memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash)); |
3922 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace); |
5e0d7cb8 |
3923 | cscipher->setcskey(keyspace); |
65a22376 |
3924 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace); |
5e0d7cb8 |
3925 | sccipher->setsckey(keyspace); |
65a22376 |
3926 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace); |
5e0d7cb8 |
3927 | cscipher->setcsiv(keyspace); |
65a22376 |
3928 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace); |
5e0d7cb8 |
3929 | sccipher->setsciv(keyspace); |
65a22376 |
3930 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace); |
5e0d7cb8 |
3931 | csmac->setcskey(keyspace); |
65a22376 |
3932 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace); |
5e0d7cb8 |
3933 | scmac->setsckey(keyspace); |
d39f364a |
3934 | |
033b4cef |
3935 | /* |
0db56f73 |
3936 | * If this is the first key exchange phase, we must pass the |
3937 | * SSH2_MSG_NEWKEYS packet to the next layer, not because it |
3938 | * wants to see it but because it will need time to initialise |
3939 | * itself before it sees an actual packet. In subsequent key |
3940 | * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because |
3941 | * it would only confuse the layer above. |
3942 | */ |
3943 | if (!first_kex) { |
32874aea |
3944 | crReturn(0); |
0db56f73 |
3945 | } |
3946 | first_kex = 0; |
3947 | |
3948 | /* |
7cca0d81 |
3949 | * Now we're encrypting. Begin returning 1 to the protocol main |
3950 | * function so that other things can run on top of the |
3951 | * transport. If we ever see a KEXINIT, we must go back to the |
3952 | * start. |
033b4cef |
3953 | */ |
e96adf72 |
3954 | while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) { |
32874aea |
3955 | crReturn(1); |
e96adf72 |
3956 | } |
5e0d7cb8 |
3957 | logevent("Server initiated key re-exchange"); |
7cca0d81 |
3958 | goto begin_key_exchange; |
e5574168 |
3959 | |
3960 | crFinish(1); |
3961 | } |
3962 | |
7cca0d81 |
3963 | /* |
783415f8 |
3964 | * Add data to an SSH2 channel output buffer. |
3965 | */ |
32874aea |
3966 | static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, |
3967 | int len) |
3968 | { |
5471d09a |
3969 | bufchain_add(&c->v.v2.outbuffer, buf, len); |
783415f8 |
3970 | } |
3971 | |
3972 | /* |
3973 | * Attempt to send data on an SSH2 channel. |
3974 | */ |
5471d09a |
3975 | static int ssh2_try_send(struct ssh_channel *c) |
32874aea |
3976 | { |
5471d09a |
3977 | while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) { |
3978 | int len; |
3979 | void *data; |
3980 | bufchain_prefix(&c->v.v2.outbuffer, &data, &len); |
3981 | if ((unsigned)len > c->v.v2.remwindow) |
3982 | len = c->v.v2.remwindow; |
3983 | if ((unsigned)len > c->v.v2.remmaxpkt) |
3984 | len = c->v.v2.remmaxpkt; |
32874aea |
3985 | ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA); |
3986 | ssh2_pkt_adduint32(c->remoteid); |
3987 | ssh2_pkt_addstring_start(); |
5471d09a |
3988 | ssh2_pkt_addstring_data(data, len); |
32874aea |
3989 | ssh2_pkt_send(); |
5471d09a |
3990 | bufchain_consume(&c->v.v2.outbuffer, len); |
3991 | c->v.v2.remwindow -= len; |
3992 | } |
3993 | |
3994 | /* |
3995 | * After having sent as much data as we can, return the amount |
3996 | * still buffered. |
3997 | */ |
3998 | return bufchain_size(&c->v.v2.outbuffer); |
3999 | } |
4000 | |
4001 | /* |
4002 | * Potentially enlarge the window on an SSH2 channel. |
4003 | */ |
4004 | static void ssh2_set_window(struct ssh_channel *c, unsigned newwin) |
4005 | { |
6b69f42e |
4006 | /* |
4007 | * Never send WINDOW_ADJUST for a channel that the remote side |
4008 | * already thinks it's closed; there's no point, since it won't |
4009 | * be sending any more data anyway. |
4010 | */ |
4011 | if (c->closes != 0) |
4012 | return; |
4013 | |
5471d09a |
4014 | if (newwin > c->v.v2.locwindow) { |
4015 | ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
4016 | ssh2_pkt_adduint32(c->remoteid); |
4017 | ssh2_pkt_adduint32(newwin - c->v.v2.locwindow); |
4018 | ssh2_pkt_send(); |
4019 | c->v.v2.locwindow = newwin; |
783415f8 |
4020 | } |
4021 | } |
4022 | |
4023 | /* |
7cca0d81 |
4024 | * Handle the SSH2 userauth and connection layers. |
4025 | */ |
4026 | static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) |
4027 | { |
65a22376 |
4028 | static enum { |
32874aea |
4029 | AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE, |
761187b6 |
4030 | AUTH_PASSWORD, |
4031 | AUTH_KEYBOARD_INTERACTIVE |
65a22376 |
4032 | } method; |
1408a877 |
4033 | static enum { |
32874aea |
4034 | AUTH_TYPE_NONE, |
4035 | AUTH_TYPE_PUBLICKEY, |
4036 | AUTH_TYPE_PUBLICKEY_OFFER_LOUD, |
4037 | AUTH_TYPE_PUBLICKEY_OFFER_QUIET, |
761187b6 |
4038 | AUTH_TYPE_PASSWORD, |
4bdf7c46 |
4039 | AUTH_TYPE_KEYBOARD_INTERACTIVE, |
4040 | AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET |
1408a877 |
4041 | } type; |
761187b6 |
4042 | static int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter; |
4043 | static int tried_pubkey_config, tried_agent, tried_keyb_inter; |
b3186d64 |
4044 | static int kbd_inter_running; |
1408a877 |
4045 | static int we_are_in; |
45068b27 |
4046 | static int num_prompts, curr_prompt, echo; |
65a22376 |
4047 | static char username[100]; |
7e9b7f4b |
4048 | static int got_username; |
65a22376 |
4049 | static char pwprompt[200]; |
4050 | static char password[100]; |
396778f1 |
4051 | static void *publickey_blob; |
4052 | static int publickey_bloblen; |
7cca0d81 |
4053 | |
e5574168 |
4054 | crBegin; |
4055 | |
7cca0d81 |
4056 | /* |
4057 | * Request userauth protocol, and await a response to it. |
4058 | */ |
4059 | ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST); |
4060 | ssh2_pkt_addstring("ssh-userauth"); |
4061 | ssh2_pkt_send(); |
4062 | crWaitUntilV(ispkt); |
8d5de777 |
4063 | if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) { |
32874aea |
4064 | bombout(("Server refused user authentication protocol")); |
4065 | crReturnV; |
8d5de777 |
4066 | } |
7cca0d81 |
4067 | |
4068 | /* |
1408a877 |
4069 | * We repeat this whole loop, including the username prompt, |
4070 | * until we manage a successful authentication. If the user |
4071 | * types the wrong _password_, they are sent back to the |
4072 | * beginning to try another username. (If they specify a |
4073 | * username in the config, they are never asked, even if they |
4074 | * do give a wrong password.) |
4075 | * |
4076 | * I think this best serves the needs of |
4077 | * |
4078 | * - the people who have no configuration, no keys, and just |
4079 | * want to try repeated (username,password) pairs until they |
4080 | * type both correctly |
4081 | * |
4082 | * - people who have keys and configuration but occasionally |
4083 | * need to fall back to passwords |
4084 | * |
4085 | * - people with a key held in Pageant, who might not have |
4086 | * logged in to a particular machine before; so they want to |
4087 | * type a username, and then _either_ their key will be |
4088 | * accepted, _or_ they will type a password. If they mistype |
4089 | * the username they will want to be able to get back and |
4090 | * retype it! |
7cca0d81 |
4091 | */ |
5bb641e1 |
4092 | username[0] = '\0'; |
7e9b7f4b |
4093 | got_username = FALSE; |
1408a877 |
4094 | do { |
4095 | static int pos; |
7cca0d81 |
4096 | static char c; |
e5574168 |
4097 | |
1408a877 |
4098 | /* |
4099 | * Get a username. |
4100 | */ |
4101 | pos = 0; |
7e9b7f4b |
4102 | if (got_username && !cfg.change_username) { |
5bb641e1 |
4103 | /* |
4104 | * We got a username last time round this loop, and |
4105 | * with change_username turned off we don't try to get |
4106 | * it again. |
4107 | */ |
4108 | } else if ((flags & FLAG_INTERACTIVE) && !*cfg.username) { |
c0a81592 |
4109 | if (ssh_get_line && !ssh_getline_pw_only) { |
32874aea |
4110 | if (!ssh_get_line("login as: ", |
4111 | username, sizeof(username), FALSE)) { |
4112 | /* |
4113 | * get_line failed to get a username. |
4114 | * Terminate. |
4115 | */ |
4116 | logevent("No username provided. Abandoning session."); |
4117 | ssh_state = SSH_STATE_CLOSED; |
4118 | crReturnV; |
4119 | } |
4120 | } else { |
4121 | c_write_str("login as: "); |
4122 | ssh_send_ok = 1; |
4123 | while (pos >= 0) { |
4124 | crWaitUntilV(!ispkt); |
4125 | while (inlen--) |
4126 | switch (c = *in++) { |
4127 | case 10: |
4128 | case 13: |
4129 | username[pos] = 0; |
4130 | pos = -1; |
4131 | break; |
4132 | case 8: |
4133 | case 127: |
4134 | if (pos > 0) { |
4135 | c_write_str("\b \b"); |
4136 | pos--; |
4137 | } |
4138 | break; |
4139 | case 21: |
4140 | case 27: |
4141 | while (pos > 0) { |
4142 | c_write_str("\b \b"); |
4143 | pos--; |
4144 | } |
4145 | break; |
4146 | case 3: |
4147 | case 4: |
93b581bd |
4148 | cleanup_exit(0); |
32874aea |
4149 | break; |
4150 | default: |
4151 | if (((c >= ' ' && c <= '~') || |
51b2fb65 |
4152 | ((unsigned char) c >= 160)) |
4153 | && pos < sizeof(username)-1) { |
32874aea |
4154 | username[pos++] = c; |
4155 | c_write(&c, 1); |
4156 | } |
4157 | break; |
4158 | } |
4159 | } |
4160 | } |
1408a877 |
4161 | c_write_str("\r\n"); |
7cca0d81 |
4162 | username[strcspn(username, "\n\r")] = '\0'; |
4163 | } else { |
4164 | char stuff[200]; |
4165 | strncpy(username, cfg.username, 99); |
4166 | username[99] = '\0'; |
65a22376 |
4167 | if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) { |
7cca0d81 |
4168 | sprintf(stuff, "Using username \"%s\".\r\n", username); |
1408a877 |
4169 | c_write_str(stuff); |
7cca0d81 |
4170 | } |
4171 | } |
7e9b7f4b |
4172 | got_username = TRUE; |
7cca0d81 |
4173 | |
65a22376 |
4174 | /* |
1408a877 |
4175 | * Send an authentication request using method "none": (a) |
4176 | * just in case it succeeds, and (b) so that we know what |
4177 | * authentication methods we can usefully try next. |
65a22376 |
4178 | */ |
00db133f |
4179 | ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; |
4180 | |
1408a877 |
4181 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
4182 | ssh2_pkt_addstring(username); |
32874aea |
4183 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
1408a877 |
4184 | ssh2_pkt_addstring("none"); /* method */ |
4185 | ssh2_pkt_send(); |
4186 | type = AUTH_TYPE_NONE; |
4187 | gotit = FALSE; |
4188 | we_are_in = FALSE; |
7cca0d81 |
4189 | |
1408a877 |
4190 | tried_pubkey_config = FALSE; |
1983e559 |
4191 | tried_agent = FALSE; |
b3186d64 |
4192 | tried_keyb_inter = FALSE; |
4193 | kbd_inter_running = FALSE; |
396778f1 |
4194 | /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */ |
4195 | if (*cfg.keyfile) { |
231ee168 |
4196 | int keytype; |
4197 | logeventf("Reading private key file \"%.150s\"", cfg.keyfile); |
4198 | keytype = key_type(cfg.keyfile); |
4199 | if (keytype == SSH_KEYTYPE_SSH2) |
4200 | publickey_blob = ssh2_userkey_loadpub(cfg.keyfile, NULL, |
4201 | &publickey_bloblen); |
4202 | else { |
4203 | char msgbuf[256]; |
4204 | logeventf("Unable to use this key file (%s)", |
4205 | key_type_to_str(keytype)); |
4206 | sprintf(msgbuf, "Unable to use key file \"%.150s\" (%s)\r\n", |
4207 | cfg.keyfile, key_type_to_str(keytype)); |
4208 | c_write_str(msgbuf); |
4209 | publickey_blob = NULL; |
4210 | } |
396778f1 |
4211 | } else |
4212 | publickey_blob = NULL; |
65a22376 |
4213 | |
1408a877 |
4214 | while (1) { |
4215 | /* |
4216 | * Wait for the result of the last authentication request. |
4217 | */ |
4218 | if (!gotit) |
4219 | crWaitUntilV(ispkt); |
4220 | while (pktin.type == SSH2_MSG_USERAUTH_BANNER) { |
32874aea |
4221 | char *banner; |
4222 | int size; |
4223 | /* |
4224 | * Don't show the banner if we're operating in |
4225 | * non-verbose non-interactive mode. (It's probably |
4226 | * a script, which means nobody will read the |
4227 | * banner _anyway_, and moreover the printing of |
4228 | * the banner will screw up processing on the |
4229 | * output of (say) plink.) |
4230 | */ |
4231 | if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) { |
4232 | ssh2_pkt_getstring(&banner, &size); |
4233 | if (banner) |
4234 | c_write_untrusted(banner, size); |
4235 | } |
1408a877 |
4236 | crWaitUntilV(ispkt); |
4237 | } |
4238 | if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) { |
4239 | logevent("Access granted"); |
4240 | we_are_in = TRUE; |
4241 | break; |
4242 | } |
65a22376 |
4243 | |
b3186d64 |
4244 | if (kbd_inter_running && |
4245 | pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) { |
4246 | /* |
45068b27 |
4247 | * This is either a further set-of-prompts packet |
4248 | * in keyboard-interactive authentication, or it's |
4249 | * the same one and we came back here with `gotit' |
4250 | * set. In the former case, we must reset the |
4251 | * curr_prompt variable. |
b3186d64 |
4252 | */ |
45068b27 |
4253 | if (!gotit) |
4254 | curr_prompt = 0; |
6bb26b30 |
4255 | } else if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) { |
b3186d64 |
4256 | bombout(("Strange packet received during authentication: type %d", |
1408a877 |
4257 | pktin.type)); |
38c4a8da |
4258 | crReturnV; |
65a22376 |
4259 | } |
4260 | |
1408a877 |
4261 | gotit = FALSE; |
65a22376 |
4262 | |
1408a877 |
4263 | /* |
4264 | * OK, we're now sitting on a USERAUTH_FAILURE message, so |
4265 | * we can look at the string in it and know what we can |
4266 | * helpfully try next. |
4267 | */ |
b3186d64 |
4268 | if (pktin.type == SSH2_MSG_USERAUTH_FAILURE) { |
1408a877 |
4269 | char *methods; |
4270 | int methlen; |
4271 | ssh2_pkt_getstring(&methods, &methlen); |
b3186d64 |
4272 | kbd_inter_running = FALSE; |
1408a877 |
4273 | if (!ssh2_pkt_getbool()) { |
4274 | /* |
4275 | * We have received an unequivocal Access |
4276 | * Denied. This can translate to a variety of |
4277 | * messages: |
4278 | * |
4279 | * - if we'd just tried "none" authentication, |
4280 | * it's not worth printing anything at all |
4281 | * |
4282 | * - if we'd just tried a public key _offer_, |
4283 | * the message should be "Server refused our |
4284 | * key" (or no message at all if the key |
4285 | * came from Pageant) |
4286 | * |
4287 | * - if we'd just tried anything else, the |
4288 | * message really should be "Access denied". |
4289 | * |
4290 | * Additionally, if we'd just tried password |
4291 | * authentication, we should break out of this |
4292 | * whole loop so as to go back to the username |
4293 | * prompt. |
4294 | */ |
4295 | if (type == AUTH_TYPE_NONE) { |
4296 | /* do nothing */ |
4297 | } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD || |
4298 | type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) { |
4299 | if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD) |
4300 | c_write_str("Server refused our key\r\n"); |
4301 | logevent("Server refused public key"); |
4bdf7c46 |
4302 | } else if (type == AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) { |
4303 | /* server declined keyboard-interactive; ignore */ |
1408a877 |
4304 | } else { |
4305 | c_write_str("Access denied\r\n"); |
4306 | logevent("Access denied"); |
4307 | if (type == AUTH_TYPE_PASSWORD) { |
4308 | we_are_in = FALSE; |
4309 | break; |
4310 | } |
4311 | } |
4312 | } else { |
4313 | c_write_str("Further authentication required\r\n"); |
4314 | logevent("Further authentication required"); |
4315 | } |
65a22376 |
4316 | |
32874aea |
4317 | can_pubkey = |
4318 | in_commasep_string("publickey", methods, methlen); |
4319 | can_passwd = |
4320 | in_commasep_string("password", methods, methlen); |
f091e308 |
4321 | can_keyb_inter = cfg.try_ki_auth && |
761187b6 |
4322 | in_commasep_string("keyboard-interactive", methods, methlen); |
1408a877 |
4323 | } |
65a22376 |
4324 | |
1408a877 |
4325 | method = 0; |
00db133f |
4326 | ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; |
65a22376 |
4327 | |
78afa559 |
4328 | if (!method && can_pubkey && agent_exists() && !tried_agent) { |
1983e559 |
4329 | /* |
4330 | * Attempt public-key authentication using Pageant. |
4331 | */ |
4332 | static unsigned char request[5], *response, *p; |
4333 | static int responselen; |
4334 | static int i, nkeys; |
4335 | static int authed = FALSE; |
4336 | void *r; |
4337 | |
c0a81592 |
4338 | ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; |
00db133f |
4339 | ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY; |
4340 | |
1983e559 |
4341 | tried_agent = TRUE; |
4342 | |
4343 | logevent("Pageant is running. Requesting keys."); |
4344 | |
4345 | /* Request the keys held by the agent. */ |
4346 | PUT_32BIT(request, 1); |
4347 | request[4] = SSH2_AGENTC_REQUEST_IDENTITIES; |
4348 | agent_query(request, 5, &r, &responselen); |
32874aea |
4349 | response = (unsigned char *) r; |
95797139 |
4350 | if (response && responselen >= 5 && |
32874aea |
4351 | response[4] == SSH2_AGENT_IDENTITIES_ANSWER) { |
1983e559 |
4352 | p = response + 5; |
32874aea |
4353 | nkeys = GET_32BIT(p); |
4354 | p += 4; |
4355 | { |
4356 | char buf[64]; |
4357 | sprintf(buf, "Pageant has %d SSH2 keys", nkeys); |
4358 | logevent(buf); |
4359 | } |
1983e559 |
4360 | for (i = 0; i < nkeys; i++) { |
4361 | static char *pkblob, *alg, *commentp; |
4362 | static int pklen, alglen, commentlen; |
4363 | static int siglen, retlen, len; |
4364 | static char *q, *agentreq, *ret; |
2d466ffd |
4365 | void *vret; |
1983e559 |
4366 | |
32874aea |
4367 | { |
4368 | char buf[64]; |
4369 | sprintf(buf, "Trying Pageant key #%d", i); |
4370 | logevent(buf); |
4371 | } |
4372 | pklen = GET_32BIT(p); |
4373 | p += 4; |
396778f1 |
4374 | if (publickey_blob && |
4375 | pklen == publickey_bloblen && |
4376 | !memcmp(p, publickey_blob, publickey_bloblen)) { |
4377 | logevent("This key matches configured key file"); |
4378 | tried_pubkey_config = 1; |
4379 | } |
32874aea |
4380 | pkblob = p; |
4381 | p += pklen; |
1983e559 |
4382 | alglen = GET_32BIT(pkblob); |
4383 | alg = pkblob + 4; |
32874aea |
4384 | commentlen = GET_32BIT(p); |
4385 | p += 4; |
4386 | commentp = p; |
4387 | p += commentlen; |
1983e559 |
4388 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
4389 | ssh2_pkt_addstring(username); |
32874aea |
4390 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
4391 | ssh2_pkt_addstring("publickey"); /* method */ |
4392 | ssh2_pkt_addbool(FALSE); /* no signature included */ |
1983e559 |
4393 | ssh2_pkt_addstring_start(); |
4394 | ssh2_pkt_addstring_data(alg, alglen); |
4395 | ssh2_pkt_addstring_start(); |
4396 | ssh2_pkt_addstring_data(pkblob, pklen); |
4397 | ssh2_pkt_send(); |
4398 | |
4399 | crWaitUntilV(ispkt); |
4400 | if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) { |
4401 | logevent("Key refused"); |
4402 | continue; |
4403 | } |
4404 | |
32874aea |
4405 | if (flags & FLAG_VERBOSE) { |
4406 | c_write_str |
4407 | ("Authenticating with public key \""); |
4408 | c_write(commentp, commentlen); |
4409 | c_write_str("\" from agent\r\n"); |
4410 | } |
1983e559 |
4411 | |
4412 | /* |
4413 | * Server is willing to accept the key. |
4414 | * Construct a SIGN_REQUEST. |
4415 | */ |
4416 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
4417 | ssh2_pkt_addstring(username); |
32874aea |
4418 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
4419 | ssh2_pkt_addstring("publickey"); /* method */ |
1983e559 |
4420 | ssh2_pkt_addbool(TRUE); |
4421 | ssh2_pkt_addstring_start(); |
4422 | ssh2_pkt_addstring_data(alg, alglen); |
4423 | ssh2_pkt_addstring_start(); |
4424 | ssh2_pkt_addstring_data(pkblob, pklen); |
4425 | |
4426 | siglen = pktout.length - 5 + 4 + 20; |
32874aea |
4427 | len = 1; /* message type */ |
4428 | len += 4 + pklen; /* key blob */ |
4429 | len += 4 + siglen; /* data to sign */ |
4430 | len += 4; /* flags */ |
1983e559 |
4431 | agentreq = smalloc(4 + len); |
4432 | PUT_32BIT(agentreq, len); |
4433 | q = agentreq + 4; |
4434 | *q++ = SSH2_AGENTC_SIGN_REQUEST; |
32874aea |
4435 | PUT_32BIT(q, pklen); |
4436 | q += 4; |
4437 | memcpy(q, pkblob, pklen); |
4438 | q += pklen; |
4439 | PUT_32BIT(q, siglen); |
4440 | q += 4; |
1983e559 |
4441 | /* Now the data to be signed... */ |
32874aea |
4442 | PUT_32BIT(q, 20); |
4443 | q += 4; |
4444 | memcpy(q, ssh2_session_id, 20); |
4445 | q += 20; |
4446 | memcpy(q, pktout.data + 5, pktout.length - 5); |
4447 | q += pktout.length - 5; |
1983e559 |
4448 | /* And finally the (zero) flags word. */ |
4449 | PUT_32BIT(q, 0); |
2d466ffd |
4450 | agent_query(agentreq, len + 4, &vret, &retlen); |
4451 | ret = vret; |
1983e559 |
4452 | sfree(agentreq); |
4453 | if (ret) { |
4454 | if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) { |
4455 | logevent("Sending Pageant's response"); |
1dd353b5 |
4456 | ssh2_add_sigblob(pkblob, pklen, |
4457 | ret + 9, GET_32BIT(ret + 5)); |
1983e559 |
4458 | ssh2_pkt_send(); |
4459 | authed = TRUE; |
4460 | break; |
4461 | } else { |
32874aea |
4462 | logevent |
4463 | ("Pageant failed to answer challenge"); |
1983e559 |
4464 | sfree(ret); |
4465 | } |
4466 | } |
4467 | } |
4468 | if (authed) |
4469 | continue; |
4470 | } |
4471 | } |
4472 | |
231ee168 |
4473 | if (!method && can_pubkey && publickey_blob |
32874aea |
4474 | && !tried_pubkey_config) { |
1408a877 |
4475 | unsigned char *pub_blob; |
4476 | char *algorithm, *comment; |
4477 | int pub_blob_len; |
65a22376 |
4478 | |
1408a877 |
4479 | tried_pubkey_config = TRUE; |
65a22376 |
4480 | |
c0a81592 |
4481 | ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; |
00db133f |
4482 | ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY; |
4483 | |
65a22376 |
4484 | /* |
1408a877 |
4485 | * Try the public key supplied in the configuration. |
4486 | * |
4487 | * First, offer the public blob to see if the server is |
4488 | * willing to accept it. |
65a22376 |
4489 | */ |
1408a877 |
4490 | pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm, |
4491 | &pub_blob_len); |
4492 | if (pub_blob) { |
4493 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
4494 | ssh2_pkt_addstring(username); |
32874aea |
4495 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
4496 | ssh2_pkt_addstring("publickey"); /* method */ |
4497 | ssh2_pkt_addbool(FALSE); /* no signature included */ |
1408a877 |
4498 | ssh2_pkt_addstring(algorithm); |
4499 | ssh2_pkt_addstring_start(); |
4500 | ssh2_pkt_addstring_data(pub_blob, pub_blob_len); |
4501 | ssh2_pkt_send(); |
32874aea |
4502 | logevent("Offered public key"); /* FIXME */ |
1408a877 |
4503 | |
4504 | crWaitUntilV(ispkt); |
4505 | if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) { |
4506 | gotit = TRUE; |
4507 | type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD; |
32874aea |
4508 | continue; /* key refused; give up on it */ |
1408a877 |
4509 | } |
65a22376 |
4510 | |
1408a877 |
4511 | logevent("Offer of public key accepted"); |
65a22376 |
4512 | /* |
1408a877 |
4513 | * Actually attempt a serious authentication using |
4514 | * the key. |
65a22376 |
4515 | */ |
1408a877 |
4516 | if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) { |
32874aea |
4517 | sprintf(pwprompt, |
4518 | "Passphrase for key \"%.100s\": ", |
4519 | comment); |
1408a877 |
4520 | need_pw = TRUE; |
4521 | } else { |
4522 | need_pw = FALSE; |
4523 | } |
4524 | c_write_str("Authenticating with public key \""); |
4525 | c_write_str(comment); |
4526 | c_write_str("\"\r\n"); |
4527 | method = AUTH_PUBLICKEY_FILE; |
65a22376 |
4528 | } |
1408a877 |
4529 | } |
4530 | |
af659722 |
4531 | if (!method && can_keyb_inter && !tried_keyb_inter) { |
4532 | method = AUTH_KEYBOARD_INTERACTIVE; |
4533 | type = AUTH_TYPE_KEYBOARD_INTERACTIVE; |
4534 | tried_keyb_inter = TRUE; |
4535 | |
c0a81592 |
4536 | ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; |
00db133f |
4537 | ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER; |
4538 | |
af659722 |
4539 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
4540 | ssh2_pkt_addstring(username); |
4541 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
4542 | ssh2_pkt_addstring("keyboard-interactive"); /* method */ |
4543 | ssh2_pkt_addstring(""); /* lang */ |
4544 | ssh2_pkt_addstring(""); |
4545 | ssh2_pkt_send(); |
4546 | |
4547 | crWaitUntilV(ispkt); |
4548 | if (pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) { |
4549 | if (pktin.type == SSH2_MSG_USERAUTH_FAILURE) |
4550 | gotit = TRUE; |
4551 | logevent("Keyboard-interactive authentication refused"); |
4552 | type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET; |
4553 | continue; |
4554 | } |
4555 | |
4556 | kbd_inter_running = TRUE; |
45068b27 |
4557 | curr_prompt = 0; |
af659722 |
4558 | } |
4559 | |
4560 | if (kbd_inter_running) { |
4561 | method = AUTH_KEYBOARD_INTERACTIVE; |
4562 | type = AUTH_TYPE_KEYBOARD_INTERACTIVE; |
4563 | tried_keyb_inter = TRUE; |
4564 | |
c0a81592 |
4565 | ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; |
00db133f |
4566 | ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER; |
4567 | |
45068b27 |
4568 | if (curr_prompt == 0) { |
4569 | /* |
4570 | * We've got a fresh USERAUTH_INFO_REQUEST. |
4571 | * Display header data, and start going through |
4572 | * the prompts. |
4573 | */ |
4574 | char *name, *inst, *lang; |
4575 | int name_len, inst_len, lang_len; |
4576 | |
af659722 |
4577 | ssh2_pkt_getstring(&name, &name_len); |
4578 | ssh2_pkt_getstring(&inst, &inst_len); |
4579 | ssh2_pkt_getstring(&lang, &lang_len); |
45068b27 |
4580 | if (name_len > 0) { |
af659722 |
4581 | c_write_untrusted(name, name_len); |
45068b27 |
4582 | c_write_str("\n"); |
4583 | } |
4584 | if (inst_len > 0) { |
af659722 |
4585 | c_write_untrusted(inst, inst_len); |
45068b27 |
4586 | c_write_str("\n"); |
4587 | } |
af659722 |
4588 | num_prompts = ssh2_pkt_getuint32(); |
45068b27 |
4589 | } |
af659722 |
4590 | |
45068b27 |
4591 | /* |
4592 | * If there are prompts remaining in the packet, |
4593 | * display one and get a response. |
4594 | */ |
4595 | if (curr_prompt < num_prompts) { |
4596 | char *prompt; |
4597 | int prompt_len; |
af659722 |
4598 | |
45068b27 |
4599 | ssh2_pkt_getstring(&prompt, &prompt_len); |
4600 | if (prompt_len > 0) { |
4601 | strncpy(pwprompt, prompt, sizeof(pwprompt)); |
4602 | pwprompt[prompt_len < sizeof(pwprompt) ? |
4603 | prompt_len : sizeof(pwprompt)-1] = '\0'; |
4604 | } else { |
4605 | strcpy(pwprompt, |
4606 | "<server failed to send prompt>: "); |
4607 | } |
af659722 |
4608 | echo = ssh2_pkt_getbool(); |
45068b27 |
4609 | need_pw = TRUE; |
4610 | } else |
4611 | need_pw = FALSE; |
af659722 |
4612 | } |
4613 | |
1408a877 |
4614 | if (!method && can_passwd) { |
4615 | method = AUTH_PASSWORD; |
c0a81592 |
4616 | ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; |
00db133f |
4617 | ssh_pkt_ctx |= SSH2_PKTCTX_PASSWORD; |
32874aea |
4618 | sprintf(pwprompt, "%.90s@%.90s's password: ", username, |
4619 | savedhost); |
1408a877 |
4620 | need_pw = TRUE; |
4621 | } |
4622 | |
4623 | if (need_pw) { |
fa17a66e |
4624 | if (ssh_get_line) { |
4625 | if (!ssh_get_line(pwprompt, password, |
32874aea |
4626 | sizeof(password), TRUE)) { |
1408a877 |
4627 | /* |
fa17a66e |
4628 | * get_line failed to get a password (for |
4629 | * example because one was supplied on the |
4630 | * command line which has already failed to |
4631 | * work). Terminate. |
1408a877 |
4632 | */ |
2bc6a386 |
4633 | ssh2_pkt_init(SSH2_MSG_DISCONNECT); |
4634 | ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION); |
4635 | ssh2_pkt_addstring |
4636 | ("No more passwords available to try"); |
4637 | ssh2_pkt_addstring("en"); /* language tag */ |
4638 | ssh2_pkt_send(); |
247308b5 |
4639 | logevent("Unable to authenticate"); |
2bc6a386 |
4640 | connection_fatal("Unable to authenticate"); |
1408a877 |
4641 | ssh_state = SSH_STATE_CLOSED; |
4642 | crReturnV; |
4643 | } |
4644 | } else { |
4645 | static int pos = 0; |
4646 | static char c; |
4647 | |
761187b6 |
4648 | c_write_untrusted(pwprompt, strlen(pwprompt)); |
1408a877 |
4649 | ssh_send_ok = 1; |
4650 | |
4651 | pos = 0; |
4652 | while (pos >= 0) { |
4653 | crWaitUntilV(!ispkt); |
32874aea |
4654 | while (inlen--) |
4655 | switch (c = *in++) { |
4656 | case 10: |
4657 | case 13: |
4658 | password[pos] = 0; |
4659 | pos = -1; |
4660 | break; |
4661 | case 8: |
4662 | case 127: |
4663 | if (pos > 0) |
4664 | pos--; |
4665 | break; |
4666 | case 21: |
4667 | case 27: |
4668 | pos = 0; |
4669 | break; |
4670 | case 3: |
4671 | case 4: |
93b581bd |
4672 | cleanup_exit(0); |
32874aea |
4673 | break; |
4674 | default: |
51b2fb65 |
4675 | if (pos < sizeof(password)-1) |
32874aea |
4676 | password[pos++] = c; |
4677 | break; |
4678 | } |
65a22376 |
4679 | } |
1408a877 |
4680 | c_write_str("\r\n"); |
65a22376 |
4681 | } |
65a22376 |
4682 | } |
65a22376 |
4683 | |
1408a877 |
4684 | if (method == AUTH_PUBLICKEY_FILE) { |
4685 | /* |
4686 | * We have our passphrase. Now try the actual authentication. |
4687 | */ |
4688 | struct ssh2_userkey *key; |
65a22376 |
4689 | |
1408a877 |
4690 | key = ssh2_load_userkey(cfg.keyfile, password); |
4691 | if (key == SSH2_WRONG_PASSPHRASE || key == NULL) { |
4692 | if (key == SSH2_WRONG_PASSPHRASE) { |
4693 | c_write_str("Wrong passphrase\r\n"); |
4694 | tried_pubkey_config = FALSE; |
4695 | } else { |
4696 | c_write_str("Unable to load private key\r\n"); |
4697 | tried_pubkey_config = TRUE; |
4698 | } |
4699 | /* Send a spurious AUTH_NONE to return to the top. */ |
4700 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
4701 | ssh2_pkt_addstring(username); |
32874aea |
4702 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
4703 | ssh2_pkt_addstring("none"); /* method */ |
1408a877 |
4704 | ssh2_pkt_send(); |
4705 | type = AUTH_TYPE_NONE; |
4706 | } else { |
1dd353b5 |
4707 | unsigned char *pkblob, *sigblob, *sigdata; |
4708 | int pkblob_len, sigblob_len, sigdata_len; |
65a22376 |
4709 | |
1408a877 |
4710 | /* |
4711 | * We have loaded the private key and the server |
4712 | * has announced that it's willing to accept it. |
4713 | * Hallelujah. Generate a signature and send it. |
4714 | */ |
4715 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
4716 | ssh2_pkt_addstring(username); |
32874aea |
4717 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
4718 | ssh2_pkt_addstring("publickey"); /* method */ |
1408a877 |
4719 | ssh2_pkt_addbool(TRUE); |
4720 | ssh2_pkt_addstring(key->alg->name); |
1dd353b5 |
4721 | pkblob = key->alg->public_blob(key->data, &pkblob_len); |
1408a877 |
4722 | ssh2_pkt_addstring_start(); |
1dd353b5 |
4723 | ssh2_pkt_addstring_data(pkblob, pkblob_len); |
1408a877 |
4724 | |
4725 | /* |
4726 | * The data to be signed is: |
4727 | * |
4728 | * string session-id |
4729 | * |
4730 | * followed by everything so far placed in the |
4731 | * outgoing packet. |
4732 | */ |
4733 | sigdata_len = pktout.length - 5 + 4 + 20; |
4734 | sigdata = smalloc(sigdata_len); |
4735 | PUT_32BIT(sigdata, 20); |
32874aea |
4736 | memcpy(sigdata + 4, ssh2_session_id, 20); |
4737 | memcpy(sigdata + 24, pktout.data + 5, |
4738 | pktout.length - 5); |
1dd353b5 |
4739 | sigblob = key->alg->sign(key->data, sigdata, |
4740 | sigdata_len, &sigblob_len); |
4741 | ssh2_add_sigblob(pkblob, pkblob_len, |
4742 | sigblob, sigblob_len); |
4743 | sfree(pkblob); |
4744 | sfree(sigblob); |
1408a877 |
4745 | sfree(sigdata); |
4746 | |
4747 | ssh2_pkt_send(); |
4748 | type = AUTH_TYPE_PUBLICKEY; |
4749 | } |
4750 | } else if (method == AUTH_PASSWORD) { |
65a22376 |
4751 | /* |
1408a877 |
4752 | * We send the password packet lumped tightly together with |
4753 | * an SSH_MSG_IGNORE packet. The IGNORE packet contains a |
4754 | * string long enough to make the total length of the two |
4755 | * packets constant. This should ensure that a passive |
4756 | * listener doing traffic analyis can't work out the length |
4757 | * of the password. |
4758 | * |
4759 | * For this to work, we need an assumption about the |
4760 | * maximum length of the password packet. I think 256 is |
4761 | * pretty conservative. Anyone using a password longer than |
4762 | * that probably doesn't have much to worry about from |
4763 | * people who find out how long their password is! |
65a22376 |
4764 | */ |
4765 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
4766 | ssh2_pkt_addstring(username); |
32874aea |
4767 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
1408a877 |
4768 | ssh2_pkt_addstring("password"); |
4769 | ssh2_pkt_addbool(FALSE); |
4770 | ssh2_pkt_addstring(password); |
4771 | ssh2_pkt_defer(); |
65a22376 |
4772 | /* |
1408a877 |
4773 | * We'll include a string that's an exact multiple of the |
4774 | * cipher block size. If the cipher is NULL for some |
4775 | * reason, we don't do this trick at all because we gain |
4776 | * nothing by it. |
65a22376 |
4777 | */ |
32874aea |
4778 | if (cscipher) { |
4779 | int stringlen, i; |
4780 | |
4781 | stringlen = (256 - deferred_len); |
4782 | stringlen += cscipher->blksize - 1; |
4783 | stringlen -= (stringlen % cscipher->blksize); |
4784 | if (cscomp) { |
4785 | /* |
4786 | * Temporarily disable actual compression, |
4787 | * so we can guarantee to get this string |
4788 | * exactly the length we want it. The |
4789 | * compression-disabling routine should |
4790 | * return an integer indicating how many |
4791 | * bytes we should adjust our string length |
4792 | * by. |
4793 | */ |
4794 | stringlen -= cscomp->disable_compression(); |
4795 | } |
1408a877 |
4796 | ssh2_pkt_init(SSH2_MSG_IGNORE); |
4797 | ssh2_pkt_addstring_start(); |
6e9e9520 |
4798 | for (i = 0; i < stringlen; i++) { |
32874aea |
4799 | char c = (char) random_byte(); |
4800 | ssh2_pkt_addstring_data(&c, 1); |
65a22376 |
4801 | } |
1408a877 |
4802 | ssh2_pkt_defer(); |
65a22376 |
4803 | } |
39065bed |
4804 | ssh_pkt_defersend(); |
0d43337a |
4805 | logevent("Sent password"); |
1408a877 |
4806 | type = AUTH_TYPE_PASSWORD; |
761187b6 |
4807 | } else if (method == AUTH_KEYBOARD_INTERACTIVE) { |
45068b27 |
4808 | if (curr_prompt == 0) { |
4809 | ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE); |
4810 | ssh2_pkt_adduint32(num_prompts); |
4811 | } |
4812 | if (need_pw) { /* only add pw if we just got one! */ |
4813 | ssh2_pkt_addstring(password); |
4814 | memset(password, 0, sizeof(password)); |
4815 | curr_prompt++; |
4816 | } |
4817 | if (curr_prompt >= num_prompts) { |
4818 | ssh2_pkt_send(); |
4819 | } else { |
4820 | /* |
4821 | * If there are prompts remaining, we set |
4822 | * `gotit' so that we won't attempt to get |
4823 | * another packet. Then we go back round the |
4824 | * loop and will end up retrieving another |
4825 | * prompt out of the existing packet. Funky or |
4826 | * what? |
4827 | */ |
4828 | gotit = TRUE; |
4829 | } |
761187b6 |
4830 | type = AUTH_TYPE_KEYBOARD_INTERACTIVE; |
1408a877 |
4831 | } else { |
32874aea |
4832 | c_write_str |
4833 | ("No supported authentication methods left to try!\r\n"); |
4834 | logevent |
4835 | ("No supported authentications offered. Disconnecting"); |
1408a877 |
4836 | ssh2_pkt_init(SSH2_MSG_DISCONNECT); |
4837 | ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION); |
32874aea |
4838 | ssh2_pkt_addstring |
4839 | ("No supported authentication methods available"); |
4840 | ssh2_pkt_addstring("en"); /* language tag */ |
1408a877 |
4841 | ssh2_pkt_send(); |
4842 | ssh_state = SSH_STATE_CLOSED; |
4843 | crReturnV; |
65a22376 |
4844 | } |
65a22376 |
4845 | } |
1408a877 |
4846 | } while (!we_are_in); |
7cca0d81 |
4847 | |
4848 | /* |
4849 | * Now we're authenticated for the connection protocol. The |
4850 | * connection protocol will automatically have started at this |
4851 | * point; there's no need to send SERVICE_REQUEST. |
4852 | */ |
4853 | |
4854 | /* |
4855 | * So now create a channel with a session in it. |
4856 | */ |
d2371c81 |
4857 | ssh_channels = newtree234(ssh_channelcmp); |
dcbde236 |
4858 | mainchan = smalloc(sizeof(struct ssh_channel)); |
d2371c81 |
4859 | mainchan->localid = alloc_channel_id(); |
7cca0d81 |
4860 | ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN); |
4861 | ssh2_pkt_addstring("session"); |
d211621f |
4862 | ssh2_pkt_adduint32(mainchan->localid); |
5471d09a |
4863 | mainchan->v.v2.locwindow = OUR_V2_WINSIZE; |
4864 | ssh2_pkt_adduint32(mainchan->v.v2.locwindow); /* our window size */ |
32874aea |
4865 | ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */ |
7cca0d81 |
4866 | ssh2_pkt_send(); |
4867 | crWaitUntilV(ispkt); |
4868 | if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) { |
32874aea |
4869 | bombout(("Server refused to open a session")); |
4870 | crReturnV; |
4871 | /* FIXME: error data comes back in FAILURE packet */ |
7cca0d81 |
4872 | } |
d211621f |
4873 | if (ssh2_pkt_getuint32() != mainchan->localid) { |
32874aea |
4874 | bombout(("Server's channel confirmation cited wrong channel")); |
4875 | crReturnV; |
7cca0d81 |
4876 | } |
d211621f |
4877 | mainchan->remoteid = ssh2_pkt_getuint32(); |
783415f8 |
4878 | mainchan->type = CHAN_MAINSESSION; |
4879 | mainchan->closes = 0; |
5471d09a |
4880 | mainchan->v.v2.remwindow = ssh2_pkt_getuint32(); |
4881 | mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32(); |
4882 | bufchain_init(&mainchan->v.v2.outbuffer); |
783415f8 |
4883 | add234(ssh_channels, mainchan); |
7cca0d81 |
4884 | logevent("Opened channel for session"); |
4885 | |
4886 | /* |
783415f8 |
4887 | * Potentially enable X11 forwarding. |
4888 | */ |
4889 | if (cfg.x11_forward) { |
32874aea |
4890 | char proto[20], data[64]; |
4891 | logevent("Requesting X11 forwarding"); |
4892 | x11_invent_auth(proto, sizeof(proto), data, sizeof(data)); |
4893 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
4894 | ssh2_pkt_adduint32(mainchan->remoteid); |
4895 | ssh2_pkt_addstring("x11-req"); |
4896 | ssh2_pkt_addbool(1); /* want reply */ |
4897 | ssh2_pkt_addbool(0); /* many connections */ |
4898 | ssh2_pkt_addstring(proto); |
4899 | ssh2_pkt_addstring(data); |
4900 | ssh2_pkt_adduint32(0); /* screen number */ |
4901 | ssh2_pkt_send(); |
4902 | |
4903 | do { |
4904 | crWaitUntilV(ispkt); |
4905 | if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
4906 | unsigned i = ssh2_pkt_getuint32(); |
4907 | struct ssh_channel *c; |
4908 | c = find234(ssh_channels, &i, ssh_channelfind); |
4909 | if (!c) |
4910 | continue; /* nonexistent channel */ |
5471d09a |
4911 | c->v.v2.remwindow += ssh2_pkt_getuint32(); |
32874aea |
4912 | } |
4913 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
4914 | |
4915 | if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
4916 | if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
c9886e66 |
4917 | bombout(("Unexpected response to X11 forwarding request:" |
4918 | " packet type %d", pktin.type)); |
32874aea |
4919 | crReturnV; |
4920 | } |
4921 | logevent("X11 forwarding refused"); |
4922 | } else { |
4923 | logevent("X11 forwarding enabled"); |
783415f8 |
4924 | ssh_X11_fwd_enabled = TRUE; |
32874aea |
4925 | } |
783415f8 |
4926 | } |
4927 | |
4928 | /* |
bc240b21 |
4929 | * Enable port forwardings. |
4930 | */ |
4931 | { |
4932 | static char *e; /* preserve across crReturn */ |
4933 | char type; |
4934 | int n; |
a4fc0d74 |
4935 | int sport,dport,sserv,dserv; |
bc240b21 |
4936 | char sports[256], dports[256], host[256]; |
4937 | char buf[1024]; |
a4fc0d74 |
4938 | struct servent *se; |
bc240b21 |
4939 | |
4940 | ssh_rportfwds = newtree234(ssh_rportcmp_ssh2); |
4941 | /* Add port forwardings. */ |
4942 | e = cfg.portfwd; |
4943 | while (*e) { |
4944 | type = *e++; |
4945 | n = 0; |
4946 | while (*e && *e != '\t') |
4947 | sports[n++] = *e++; |
4948 | sports[n] = 0; |
4949 | if (*e == '\t') |
4950 | e++; |
4951 | n = 0; |
4952 | while (*e && *e != ':') |
4953 | host[n++] = *e++; |
4954 | host[n] = 0; |
4955 | if (*e == ':') |
4956 | e++; |
4957 | n = 0; |
4958 | while (*e) |
4959 | dports[n++] = *e++; |
4960 | dports[n] = 0; |
4961 | e++; |
4962 | dport = atoi(dports); |
a4fc0d74 |
4963 | dserv = 0; |
4964 | if (dport == 0) { |
4965 | dserv = 1; |
4966 | se = getservbyname(dports, NULL); |
4967 | if (se != NULL) { |
4968 | dport = ntohs(se->s_port); |
4969 | } else { |
4970 | sprintf(buf, |
4971 | "Service lookup failed for destination port \"%s\"", |
4972 | dports); |
4973 | logevent(buf); |
4974 | } |
4975 | } |
bc240b21 |
4976 | sport = atoi(sports); |
a4fc0d74 |
4977 | sserv = 0; |
4978 | if (sport == 0) { |
4979 | sserv = 1; |
4980 | se = getservbyname(sports, NULL); |
4981 | if (se != NULL) { |
4982 | sport = ntohs(se->s_port); |
4983 | } else { |
4984 | sprintf(buf, |
4985 | "Service lookup failed for source port \"%s\"", |
4986 | sports); |
4987 | logevent(buf); |
4988 | } |
4989 | } |
bc240b21 |
4990 | if (sport && dport) { |
4991 | if (type == 'L') { |
4992 | pfd_addforward(host, dport, sport); |
a4fc0d74 |
4993 | sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to" |
4994 | " %s:%.*s%.*s%d%.*s", |
4995 | sserv ? strlen(sports) : 0, sports, |
4996 | sserv, "(", sport, sserv, ")", |
4997 | host, |
4998 | dserv ? strlen(dports) : 0, dports, |
4999 | dserv, "(", dport, dserv, ")"); |
bc240b21 |
5000 | logevent(buf); |
5001 | } else { |
5002 | struct ssh_rportfwd *pf; |
5003 | pf = smalloc(sizeof(*pf)); |
5004 | strcpy(pf->dhost, host); |
5005 | pf->dport = dport; |
5006 | pf->sport = sport; |
5007 | if (add234(ssh_rportfwds, pf) != pf) { |
5008 | sprintf(buf, |
95bc8819 |
5009 | "Duplicate remote port forwarding to %s:%d", |
bc240b21 |
5010 | host, dport); |
5011 | logevent(buf); |
5012 | sfree(pf); |
5013 | } else { |
a4fc0d74 |
5014 | sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s" |
5015 | " forward to %s:%.*s%.*s%d%.*s", |
5016 | sserv ? strlen(sports) : 0, sports, |
5017 | sserv, "(", sport, sserv, ")", |
5018 | host, |
5019 | dserv ? strlen(dports) : 0, dports, |
5020 | dserv, "(", dport, dserv, ")"); |
bc240b21 |
5021 | logevent(buf); |
5022 | ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST); |
5023 | ssh2_pkt_addstring("tcpip-forward"); |
5024 | ssh2_pkt_addbool(1);/* want reply */ |
beefa433 |
5025 | if (cfg.rport_acceptall) |
5026 | ssh2_pkt_addstring("0.0.0.0"); |
5027 | else |
5028 | ssh2_pkt_addstring("127.0.0.1"); |
bc240b21 |
5029 | ssh2_pkt_adduint32(sport); |
5030 | ssh2_pkt_send(); |
5031 | |
5032 | do { |
5033 | crWaitUntilV(ispkt); |
5034 | if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
5035 | unsigned i = ssh2_pkt_getuint32(); |
5036 | struct ssh_channel *c; |
5037 | c = find234(ssh_channels, &i, ssh_channelfind); |
5038 | if (!c) |
5039 | continue;/* nonexistent channel */ |
5471d09a |
5040 | c->v.v2.remwindow += ssh2_pkt_getuint32(); |
bc240b21 |
5041 | } |
5042 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
5043 | |
5044 | if (pktin.type != SSH2_MSG_REQUEST_SUCCESS) { |
5045 | if (pktin.type != SSH2_MSG_REQUEST_FAILURE) { |
c9886e66 |
5046 | bombout(("Unexpected response to port " |
5047 | "forwarding request: packet type %d", |
5048 | pktin.type)); |
bc240b21 |
5049 | crReturnV; |
5050 | } |
5051 | logevent("Server refused this port forwarding"); |
5052 | } else { |
5053 | logevent("Remote port forwarding enabled"); |
5054 | } |
5055 | } |
5056 | } |
5057 | } |
5058 | } |
5059 | } |
5060 | |
5061 | /* |
36c2a3e9 |
5062 | * Potentially enable agent forwarding. |
5063 | */ |
5064 | if (cfg.agentfwd && agent_exists()) { |
32874aea |
5065 | logevent("Requesting OpenSSH-style agent forwarding"); |
5066 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
5067 | ssh2_pkt_adduint32(mainchan->remoteid); |
5068 | ssh2_pkt_addstring("auth-agent-req@openssh.com"); |
5069 | ssh2_pkt_addbool(1); /* want reply */ |
5070 | ssh2_pkt_send(); |
5071 | |
5072 | do { |
5073 | crWaitUntilV(ispkt); |
5074 | if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
5075 | unsigned i = ssh2_pkt_getuint32(); |
5076 | struct ssh_channel *c; |
5077 | c = find234(ssh_channels, &i, ssh_channelfind); |
5078 | if (!c) |
5079 | continue; /* nonexistent channel */ |
5471d09a |
5080 | c->v.v2.remwindow += ssh2_pkt_getuint32(); |
32874aea |
5081 | } |
5082 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
5083 | |
5084 | if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
5085 | if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
c9886e66 |
5086 | bombout(("Unexpected response to agent forwarding request:" |
5087 | " packet type %d", pktin.type)); |
32874aea |
5088 | crReturnV; |
5089 | } |
5090 | logevent("Agent forwarding refused"); |
5091 | } else { |
5092 | logevent("Agent forwarding enabled"); |
36c2a3e9 |
5093 | ssh_agentfwd_enabled = TRUE; |
32874aea |
5094 | } |
36c2a3e9 |
5095 | } |
5096 | |
5097 | /* |
7cca0d81 |
5098 | * Now allocate a pty for the session. |
5099 | */ |
67779be7 |
5100 | if (!cfg.nopty) { |
32874aea |
5101 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
5102 | ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */ |
5103 | ssh2_pkt_addstring("pty-req"); |
5104 | ssh2_pkt_addbool(1); /* want reply */ |
5105 | ssh2_pkt_addstring(cfg.termtype); |
5106 | ssh2_pkt_adduint32(cols); |
5107 | ssh2_pkt_adduint32(rows); |
5108 | ssh2_pkt_adduint32(0); /* pixel width */ |
5109 | ssh2_pkt_adduint32(0); /* pixel height */ |
5110 | ssh2_pkt_addstring_start(); |
5111 | ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */ |
5112 | ssh2_pkt_send(); |
5113 | ssh_state = SSH_STATE_INTERMED; |
5114 | |
5115 | do { |
5116 | crWaitUntilV(ispkt); |
5117 | if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
5118 | unsigned i = ssh2_pkt_getuint32(); |
5119 | struct ssh_channel *c; |
5120 | c = find234(ssh_channels, &i, ssh_channelfind); |
5121 | if (!c) |
5122 | continue; /* nonexistent channel */ |
5471d09a |
5123 | c->v.v2.remwindow += ssh2_pkt_getuint32(); |
32874aea |
5124 | } |
5125 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
5126 | |
5127 | if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
5128 | if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
c9886e66 |
5129 | bombout(("Unexpected response to pty request:" |
5130 | " packet type %d", pktin.type)); |
32874aea |
5131 | crReturnV; |
5132 | } |
5133 | c_write_str("Server refused to allocate pty\r\n"); |
5134 | ssh_editing = ssh_echoing = 1; |
5135 | } else { |
5136 | logevent("Allocated pty"); |
5137 | } |
0965bee0 |
5138 | } else { |
32874aea |
5139 | ssh_editing = ssh_echoing = 1; |
7cca0d81 |
5140 | } |
5141 | |
5142 | /* |
fd5e5847 |
5143 | * Start a shell or a remote command. We may have to attempt |
5144 | * this twice if the config data has provided a second choice |
5145 | * of command. |
7cca0d81 |
5146 | */ |
fd5e5847 |
5147 | while (1) { |
5148 | int subsys; |
5149 | char *cmd; |
5150 | |
5151 | if (ssh_fallback_cmd) { |
5152 | subsys = cfg.ssh_subsys2; |
5153 | cmd = cfg.remote_cmd_ptr2; |
5154 | } else { |
5155 | subsys = cfg.ssh_subsys; |
5156 | cmd = cfg.remote_cmd_ptr; |
5157 | } |
5158 | |
5159 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
5160 | ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */ |
5161 | if (subsys) { |
5162 | ssh2_pkt_addstring("subsystem"); |
5163 | ssh2_pkt_addbool(1); /* want reply */ |
5164 | ssh2_pkt_addstring(cmd); |
5165 | } else if (*cmd) { |
5166 | ssh2_pkt_addstring("exec"); |
5167 | ssh2_pkt_addbool(1); /* want reply */ |
5168 | ssh2_pkt_addstring(cmd); |
5169 | } else { |
5170 | ssh2_pkt_addstring("shell"); |
5171 | ssh2_pkt_addbool(1); /* want reply */ |
32874aea |
5172 | } |
fd5e5847 |
5173 | ssh2_pkt_send(); |
5174 | do { |
5175 | crWaitUntilV(ispkt); |
5176 | if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
5177 | unsigned i = ssh2_pkt_getuint32(); |
5178 | struct ssh_channel *c; |
5179 | c = find234(ssh_channels, &i, ssh_channelfind); |
5180 | if (!c) |
5181 | continue; /* nonexistent channel */ |
5182 | c->v.v2.remwindow += ssh2_pkt_getuint32(); |
5183 | } |
5184 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
5185 | if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
5186 | if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
c9886e66 |
5187 | bombout(("Unexpected response to shell/command request:" |
5188 | " packet type %d", pktin.type)); |
fd5e5847 |
5189 | crReturnV; |
5190 | } |
5191 | /* |
5192 | * We failed to start the command. If this is the |
5193 | * fallback command, we really are finished; if it's |
5194 | * not, and if the fallback command exists, try falling |
5195 | * back to it before complaining. |
5196 | */ |
5197 | if (!ssh_fallback_cmd && cfg.remote_cmd_ptr2 != NULL) { |
5198 | logevent("Primary command failed; attempting fallback"); |
5199 | ssh_fallback_cmd = TRUE; |
5200 | continue; |
5201 | } |
5202 | bombout(("Server refused to start a shell/command")); |
32874aea |
5203 | crReturnV; |
fd5e5847 |
5204 | } else { |
5205 | logevent("Started a shell/command"); |
32874aea |
5206 | } |
fd5e5847 |
5207 | break; |
7cca0d81 |
5208 | } |
5209 | |
6e48c3fe |
5210 | ssh_state = SSH_STATE_SESSION; |
5211 | if (size_needed) |
5212 | ssh_size(); |
3687d221 |
5213 | if (eof_needed) |
32874aea |
5214 | ssh_special(TS_EOF); |
6e48c3fe |
5215 | |
7cca0d81 |
5216 | /* |
5217 | * Transfer data! |
5218 | */ |
760e88b2 |
5219 | ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */ |
8ccc75b0 |
5220 | ssh_send_ok = 1; |
7cca0d81 |
5221 | while (1) { |
32874aea |
5222 | static int try_send; |
e5574168 |
5223 | crReturnV; |
32874aea |
5224 | try_send = FALSE; |
7cca0d81 |
5225 | if (ispkt) { |
5226 | if (pktin.type == SSH2_MSG_CHANNEL_DATA || |
32874aea |
5227 | pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) { |
5228 | char *data; |
5229 | int length; |
5230 | unsigned i = ssh2_pkt_getuint32(); |
5231 | struct ssh_channel *c; |
5232 | c = find234(ssh_channels, &i, ssh_channelfind); |
5233 | if (!c) |
5234 | continue; /* nonexistent channel */ |
5235 | if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA && |
5236 | ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR) |
5237 | continue; /* extended but not stderr */ |
5238 | ssh2_pkt_getstring(&data, &length); |
5239 | if (data) { |
5471d09a |
5240 | int bufsize; |
5241 | c->v.v2.locwindow -= length; |
32874aea |
5242 | switch (c->type) { |
5243 | case CHAN_MAINSESSION: |
5471d09a |
5244 | bufsize = |
5245 | from_backend(pktin.type == |
5246 | SSH2_MSG_CHANNEL_EXTENDED_DATA, |
5247 | data, length); |
32874aea |
5248 | break; |
5249 | case CHAN_X11: |
5471d09a |
5250 | bufsize = x11_send(c->u.x11.s, data, length); |
32874aea |
5251 | break; |
d74d141c |
5252 | case CHAN_SOCKDATA: |
5471d09a |
5253 | bufsize = pfd_send(c->u.pfd.s, data, length); |
bc240b21 |
5254 | break; |
36c2a3e9 |
5255 | case CHAN_AGENT: |
32874aea |
5256 | while (length > 0) { |
5257 | if (c->u.a.lensofar < 4) { |
5258 | int l = min(4 - c->u.a.lensofar, length); |
5259 | memcpy(c->u.a.msglen + c->u.a.lensofar, |
5260 | data, l); |
5261 | data += l; |
5262 | length -= l; |
5263 | c->u.a.lensofar += l; |
5264 | } |
5265 | if (c->u.a.lensofar == 4) { |
5266 | c->u.a.totallen = |
5267 | 4 + GET_32BIT(c->u.a.msglen); |
5268 | c->u.a.message = smalloc(c->u.a.totallen); |
5269 | memcpy(c->u.a.message, c->u.a.msglen, 4); |
5270 | } |
5271 | if (c->u.a.lensofar >= 4 && length > 0) { |
5272 | int l = |
5273 | min(c->u.a.totallen - c->u.a.lensofar, |
5274 | length); |
5275 | memcpy(c->u.a.message + c->u.a.lensofar, |
5276 | data, l); |
5277 | data += l; |
5278 | length -= l; |
5279 | c->u.a.lensofar += l; |
5280 | } |
5281 | if (c->u.a.lensofar == c->u.a.totallen) { |
5282 | void *reply, *sentreply; |
5283 | int replylen; |
5284 | agent_query(c->u.a.message, |
5285 | c->u.a.totallen, &reply, |
5286 | &replylen); |
5287 | if (reply) |
5288 | sentreply = reply; |
5289 | else { |
5290 | /* Fake SSH_AGENT_FAILURE. */ |
5291 | sentreply = "\0\0\0\1\5"; |
5292 | replylen = 5; |
5293 | } |
5294 | ssh2_add_channel_data(c, sentreply, |
5295 | replylen); |
36c2a3e9 |
5296 | try_send = TRUE; |
32874aea |
5297 | if (reply) |
5298 | sfree(reply); |
5299 | sfree(c->u.a.message); |
5300 | c->u.a.lensofar = 0; |
5301 | } |
5302 | } |
5471d09a |
5303 | bufsize = 0; |
32874aea |
5304 | break; |
5305 | } |
5306 | /* |
5471d09a |
5307 | * If we are not buffering too much data, |
5308 | * enlarge the window again at the remote side. |
32874aea |
5309 | */ |
5471d09a |
5310 | if (bufsize < OUR_V2_WINSIZE) |
5311 | ssh2_set_window(c, OUR_V2_WINSIZE - bufsize); |
32874aea |
5312 | } |
7cca0d81 |
5313 | } else if (pktin.type == SSH2_MSG_DISCONNECT) { |
32874aea |
5314 | ssh_state = SSH_STATE_CLOSED; |
d211621f |
5315 | logevent("Received disconnect message"); |
32874aea |
5316 | crReturnV; |
d211621f |
5317 | } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) { |
32874aea |
5318 | unsigned i = ssh2_pkt_getuint32(); |
5319 | struct ssh_channel *c; |
5320 | |
5321 | c = find234(ssh_channels, &i, ssh_channelfind); |
5322 | if (!c) |
5323 | continue; /* nonexistent channel */ |
5324 | |
5325 | if (c->type == CHAN_X11) { |
5326 | /* |
5327 | * Remote EOF on an X11 channel means we should |
5328 | * wrap up and close the channel ourselves. |
5329 | */ |
5330 | x11_close(c->u.x11.s); |
5331 | sshfwd_close(c); |
5332 | } else if (c->type == CHAN_AGENT) { |
36c2a3e9 |
5333 | sshfwd_close(c); |
d74d141c |
5334 | } else if (c->type == CHAN_SOCKDATA) { |
bc240b21 |
5335 | pfd_close(c->u.pfd.s); |
5336 | sshfwd_close(c); |
36c2a3e9 |
5337 | } |
d211621f |
5338 | } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) { |
32874aea |
5339 | unsigned i = ssh2_pkt_getuint32(); |
5340 | struct ssh_channel *c; |
5341 | |
5342 | c = find234(ssh_channels, &i, ssh_channelfind); |
5343 | if (!c) |
5344 | continue; /* nonexistent channel */ |
32874aea |
5345 | /* Do pre-close processing on the channel. */ |
5346 | switch (c->type) { |
5347 | case CHAN_MAINSESSION: |
5348 | break; /* nothing to see here, move along */ |
5349 | case CHAN_X11: |
92f157bd |
5350 | if (c->u.x11.s != NULL) |
5351 | x11_close(c->u.x11.s); |
5352 | sshfwd_close(c); |
32874aea |
5353 | break; |
5354 | case CHAN_AGENT: |
92f157bd |
5355 | sshfwd_close(c); |
32874aea |
5356 | break; |
d74d141c |
5357 | case CHAN_SOCKDATA: |
92f157bd |
5358 | if (c->u.pfd.s != NULL) |
5359 | pfd_close(c->u.pfd.s); |
5360 | sshfwd_close(c); |
bc240b21 |
5361 | break; |
32874aea |
5362 | } |
92f157bd |
5363 | if (c->closes == 0) { |
5364 | ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); |
5365 | ssh2_pkt_adduint32(c->remoteid); |
5366 | ssh2_pkt_send(); |
5367 | } |
32874aea |
5368 | del234(ssh_channels, c); |
5471d09a |
5369 | bufchain_clear(&c->v.v2.outbuffer); |
32874aea |
5370 | sfree(c); |
5371 | |
5372 | /* |
5373 | * See if that was the last channel left open. |
5374 | */ |
5375 | if (count234(ssh_channels) == 0) { |
ca2914d1 |
5376 | #if 0 |
5377 | /* |
5378 | * We used to send SSH_MSG_DISCONNECT here, |
5379 | * because I'd believed that _every_ conforming |
5380 | * SSH2 connection had to end with a disconnect |
5381 | * being sent by at least one side; apparently |
5382 | * I was wrong and it's perfectly OK to |
5383 | * unceremoniously slam the connection shut |
5384 | * when you're done, and indeed OpenSSH feels |
5385 | * this is more polite than sending a |
5386 | * DISCONNECT. So now we don't. |
5387 | */ |
32874aea |
5388 | logevent("All channels closed. Disconnecting"); |
5389 | ssh2_pkt_init(SSH2_MSG_DISCONNECT); |
5390 | ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION); |
5391 | ssh2_pkt_addstring("All open channels closed"); |
5392 | ssh2_pkt_addstring("en"); /* language tag */ |
5393 | ssh2_pkt_send(); |
ca2914d1 |
5394 | #endif |
32874aea |
5395 | ssh_state = SSH_STATE_CLOSED; |
5396 | crReturnV; |
5397 | } |
5398 | continue; /* remote sends close; ignore (FIXME) */ |
7cca0d81 |
5399 | } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
32874aea |
5400 | unsigned i = ssh2_pkt_getuint32(); |
5401 | struct ssh_channel *c; |
5402 | c = find234(ssh_channels, &i, ssh_channelfind); |
5403 | if (!c) |
5404 | continue; /* nonexistent channel */ |
5471d09a |
5405 | c->v.v2.remwindow += ssh2_pkt_getuint32(); |
32874aea |
5406 | try_send = TRUE; |
bc240b21 |
5407 | } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) { |
5408 | unsigned i = ssh2_pkt_getuint32(); |
5409 | struct ssh_channel *c; |
5410 | c = find234(ssh_channels, &i, ssh_channelfind); |
5411 | if (!c) |
5412 | continue; /* nonexistent channel */ |
5413 | if (c->type != CHAN_SOCKDATA_DORMANT) |
5414 | continue; /* dunno why they're confirming this */ |
5415 | c->remoteid = ssh2_pkt_getuint32(); |
5416 | c->type = CHAN_SOCKDATA; |
5471d09a |
5417 | c->v.v2.remwindow = ssh2_pkt_getuint32(); |
5418 | c->v.v2.remmaxpkt = ssh2_pkt_getuint32(); |
4ed34d25 |
5419 | if (c->u.pfd.s) |
5420 | pfd_confirm(c->u.pfd.s); |
5421 | if (c->closes) { |
5422 | /* |
5423 | * We have a pending close on this channel, |
5424 | * which we decided on before the server acked |
5425 | * the channel open. So now we know the |
5426 | * remoteid, we can close it again. |
5427 | */ |
5428 | ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); |
5429 | ssh2_pkt_adduint32(c->remoteid); |
5430 | ssh2_pkt_send(); |
5431 | } |
724cface |
5432 | } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) { |
5433 | unsigned i = ssh2_pkt_getuint32(); |
5434 | struct ssh_channel *c; |
5435 | c = find234(ssh_channels, &i, ssh_channelfind); |
5436 | if (!c) |
5437 | continue; /* nonexistent channel */ |
5438 | if (c->type != CHAN_SOCKDATA_DORMANT) |
5439 | continue; /* dunno why they're failing this */ |
5440 | |
5441 | logevent("Forwarded connection refused by server"); |
5442 | |
5443 | pfd_close(c->u.pfd.s); |
5444 | |
5445 | del234(ssh_channels, c); |
5446 | sfree(c); |
ebb0a590 |
5447 | } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) { |
5448 | unsigned localid; |
5449 | char *type; |
5450 | int typelen, want_reply; |
5451 | struct ssh_channel *c; |
5452 | |
5453 | localid = ssh2_pkt_getuint32(); |
5454 | ssh2_pkt_getstring(&type, &typelen); |
5455 | want_reply = ssh2_pkt_getbool(); |
5456 | |
5457 | /* |
5458 | * First, check that the channel exists. Otherwise, |
5459 | * we can instantly disconnect with a rude message. |
5460 | */ |
5461 | c = find234(ssh_channels, &localid, ssh_channelfind); |
5462 | if (!c) { |
5463 | char buf[80]; |
5464 | sprintf(buf, "Received channel request for nonexistent" |
5465 | " channel %d", localid); |
5466 | logevent(buf); |
5467 | ssh2_pkt_init(SSH2_MSG_DISCONNECT); |
5468 | ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION); |
5469 | ssh2_pkt_addstring(buf); |
5470 | ssh2_pkt_addstring("en"); /* language tag */ |
5471 | ssh2_pkt_send(); |
247308b5 |
5472 | connection_fatal("%s", buf); |
ebb0a590 |
5473 | ssh_state = SSH_STATE_CLOSED; |
5474 | crReturnV; |
5475 | } |
5476 | |
5477 | /* |
d8d6c7e5 |
5478 | * Having got the channel number, we now look at |
5479 | * the request type string to see if it's something |
5480 | * we recognise. |
ebb0a590 |
5481 | */ |
d8d6c7e5 |
5482 | if (typelen == 11 && !memcmp(type, "exit-status", 11) && |
5483 | c == mainchan) { |
5484 | /* We recognise "exit-status" on the primary channel. */ |
5485 | char buf[100]; |
5486 | ssh_exitcode = ssh2_pkt_getuint32(); |
5487 | sprintf(buf, "Server sent command exit status %d", |
5488 | ssh_exitcode); |
5489 | logevent(buf); |
5490 | if (want_reply) { |
5491 | ssh2_pkt_init(SSH2_MSG_CHANNEL_SUCCESS); |
5492 | ssh2_pkt_adduint32(c->remoteid); |
5493 | ssh2_pkt_send(); |
5494 | } |
5495 | } else { |
5496 | /* |
5497 | * This is a channel request we don't know |
5498 | * about, so we now either ignore the request |
5499 | * or respond with CHANNEL_FAILURE, depending |
5500 | * on want_reply. |
5501 | */ |
5502 | if (want_reply) { |
5503 | ssh2_pkt_init(SSH2_MSG_CHANNEL_FAILURE); |
5504 | ssh2_pkt_adduint32(c->remoteid); |
5505 | ssh2_pkt_send(); |
5506 | } |
ebb0a590 |
5507 | } |
697d4856 |
5508 | } else if (pktin.type == SSH2_MSG_GLOBAL_REQUEST) { |
5509 | char *type; |
5510 | int typelen, want_reply; |
5511 | |
5512 | ssh2_pkt_getstring(&type, &typelen); |
5513 | want_reply = ssh2_pkt_getbool(); |
5514 | |
5515 | /* |
5516 | * We currently don't support any global requests |
5517 | * at all, so we either ignore the request or |
5518 | * respond with REQUEST_FAILURE, depending on |
5519 | * want_reply. |
5520 | */ |
5521 | if (want_reply) { |
5522 | ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE); |
5523 | ssh2_pkt_send(); |
5524 | } |
783415f8 |
5525 | } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) { |
32874aea |
5526 | char *type; |
5527 | int typelen; |
5528 | char *error = NULL; |
5529 | struct ssh_channel *c; |
bc240b21 |
5530 | unsigned remid, winsize, pktsize; |
32874aea |
5531 | ssh2_pkt_getstring(&type, &typelen); |
5532 | c = smalloc(sizeof(struct ssh_channel)); |
5533 | |
bc240b21 |
5534 | remid = ssh2_pkt_getuint32(); |
5535 | winsize = ssh2_pkt_getuint32(); |
5536 | pktsize = ssh2_pkt_getuint32(); |
5537 | |
32874aea |
5538 | if (typelen == 3 && !memcmp(type, "x11", 3)) { |
5539 | if (!ssh_X11_fwd_enabled) |
5540 | error = "X11 forwarding is not enabled"; |
5541 | else if (x11_init(&c->u.x11.s, cfg.x11_display, c) != |
5542 | NULL) { |
5543 | error = "Unable to open an X11 connection"; |
5544 | } else { |
5545 | c->type = CHAN_X11; |
5546 | } |
bc240b21 |
5547 | } else if (typelen == 15 && |
5548 | !memcmp(type, "forwarded-tcpip", 15)) { |
5549 | struct ssh_rportfwd pf, *realpf; |
5550 | char *dummy; |
5551 | int dummylen; |
5552 | ssh2_pkt_getstring(&dummy, &dummylen);/* skip address */ |
5553 | pf.sport = ssh2_pkt_getuint32(); |
5554 | realpf = find234(ssh_rportfwds, &pf, NULL); |
5555 | if (realpf == NULL) { |
5556 | error = "Remote port is not recognised"; |
5557 | } else { |
5558 | char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost, |
5559 | realpf->dport, c); |
5560 | char buf[1024]; |
5561 | sprintf(buf, "Received remote port open request for %s:%d", |
5562 | realpf->dhost, realpf->dport); |
5563 | logevent(buf); |
5564 | if (e != NULL) { |
5565 | sprintf(buf, "Port open failed: %s", e); |
5566 | logevent(buf); |
5567 | error = "Port open failed"; |
5568 | } else { |
5569 | logevent("Forwarded port opened successfully"); |
5570 | c->type = CHAN_SOCKDATA; |
5571 | } |
5572 | } |
32874aea |
5573 | } else if (typelen == 22 && |
36c2a3e9 |
5574 | !memcmp(type, "auth-agent@openssh.com", 3)) { |
32874aea |
5575 | if (!ssh_agentfwd_enabled) |
5576 | error = "Agent forwarding is not enabled"; |
36c2a3e9 |
5577 | else { |
32874aea |
5578 | c->type = CHAN_AGENT; /* identify channel type */ |
36c2a3e9 |
5579 | c->u.a.lensofar = 0; |
32874aea |
5580 | } |
5581 | } else { |
5582 | error = "Unsupported channel type requested"; |
5583 | } |
5584 | |
bc240b21 |
5585 | c->remoteid = remid; |
32874aea |
5586 | if (error) { |
5587 | ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE); |
5588 | ssh2_pkt_adduint32(c->remoteid); |
5589 | ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED); |
5590 | ssh2_pkt_addstring(error); |
5591 | ssh2_pkt_addstring("en"); /* language tag */ |
5592 | ssh2_pkt_send(); |
5593 | sfree(c); |
5594 | } else { |
5595 | c->localid = alloc_channel_id(); |
5596 | c->closes = 0; |
5471d09a |
5597 | c->v.v2.locwindow = OUR_V2_WINSIZE; |
5598 | c->v.v2.remwindow = winsize; |
5599 | c->v.v2.remmaxpkt = pktsize; |
5600 | bufchain_init(&c->v.v2.outbuffer); |
32874aea |
5601 | add234(ssh_channels, c); |
5602 | ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); |
5603 | ssh2_pkt_adduint32(c->remoteid); |
5604 | ssh2_pkt_adduint32(c->localid); |
5471d09a |
5605 | ssh2_pkt_adduint32(c->v.v2.locwindow); |
32874aea |
5606 | ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */ |
5607 | ssh2_pkt_send(); |
5608 | } |
7cca0d81 |
5609 | } else { |
8d5de777 |
5610 | bombout(("Strange packet received: type %d", pktin.type)); |
32874aea |
5611 | crReturnV; |
7cca0d81 |
5612 | } |
5613 | } else { |
32874aea |
5614 | /* |
5615 | * We have spare data. Add it to the channel buffer. |
5616 | */ |
5617 | ssh2_add_channel_data(mainchan, in, inlen); |
5618 | try_send = TRUE; |
5619 | } |
5620 | if (try_send) { |
5621 | int i; |
5622 | struct ssh_channel *c; |
5623 | /* |
5624 | * Try to send data on all channels if we can. |
5625 | */ |
5471d09a |
5626 | for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) { |
5627 | int bufsize = ssh2_try_send(c); |
5628 | if (bufsize == 0) { |
5629 | switch (c->type) { |
5630 | case CHAN_MAINSESSION: |
5631 | /* stdin need not receive an unthrottle |
5632 | * notification since it will be polled */ |
5633 | break; |
5634 | case CHAN_X11: |
5635 | x11_unthrottle(c->u.x11.s); |
5636 | break; |
5637 | case CHAN_AGENT: |
5638 | /* agent sockets are request/response and need no |
5639 | * buffer management */ |
5640 | break; |
5641 | case CHAN_SOCKDATA: |
5642 | pfd_unthrottle(c->u.pfd.s); |
5643 | break; |
5644 | } |
5645 | } |
5646 | } |
7cca0d81 |
5647 | } |
e5574168 |
5648 | } |
5649 | |
5650 | crFinishV; |
5651 | } |
5652 | |
5653 | /* |
7cca0d81 |
5654 | * Handle the top-level SSH2 protocol. |
5655 | */ |
5656 | static void ssh2_protocol(unsigned char *in, int inlen, int ispkt) |
5657 | { |
5658 | if (do_ssh2_transport(in, inlen, ispkt) == 0) |
32874aea |
5659 | return; |
7cca0d81 |
5660 | do_ssh2_authconn(in, inlen, ispkt); |
5661 | } |
5662 | |
5663 | /* |
8df7a775 |
5664 | * Called to set up the connection. |
374330e2 |
5665 | * |
5666 | * Returns an error message, or NULL on success. |
374330e2 |
5667 | */ |
2184a5d9 |
5668 | static char *ssh_init(char *host, int port, char **realhost, int nodelay) |
32874aea |
5669 | { |
fb09bf1c |
5670 | char *p; |
32874aea |
5671 | |
8f203108 |
5672 | #ifdef MSCRYPTOAPI |
32874aea |
5673 | if (crypto_startup() == 0) |
8f203108 |
5674 | return "Microsoft high encryption pack not installed!"; |
5675 | #endif |
374330e2 |
5676 | |
8df7a775 |
5677 | ssh_send_ok = 0; |
0965bee0 |
5678 | ssh_editing = 0; |
5679 | ssh_echoing = 0; |
5471d09a |
5680 | ssh1_throttle_count = 0; |
5681 | ssh_overall_bufsize = 0; |
fd5e5847 |
5682 | ssh_fallback_cmd = 0; |
8df7a775 |
5683 | |
2184a5d9 |
5684 | p = connect_to_host(host, port, realhost, nodelay); |
fb09bf1c |
5685 | if (p != NULL) |
5686 | return p; |
374330e2 |
5687 | |
374330e2 |
5688 | return NULL; |
5689 | } |
5690 | |
5691 | /* |
374330e2 |
5692 | * Called to send data down the Telnet connection. |
5693 | */ |
5471d09a |
5694 | static int ssh_send(char *buf, int len) |
32874aea |
5695 | { |
f78051a1 |
5696 | if (s == NULL || ssh_protocol == NULL) |
5471d09a |
5697 | return 0; |
374330e2 |
5698 | |
5699 | ssh_protocol(buf, len, 0); |
5471d09a |
5700 | |
5701 | return ssh_sendbuffer(); |
5702 | } |
5703 | |
5704 | /* |
5705 | * Called to query the current amount of buffered stdin data. |
5706 | */ |
5707 | static int ssh_sendbuffer(void) |
5708 | { |
5709 | int override_value; |
5710 | |
5711 | if (s == NULL || ssh_protocol == NULL) |
5712 | return 0; |
5713 | |
5714 | /* |
5715 | * If the SSH socket itself has backed up, add the total backup |
5716 | * size on that to any individual buffer on the stdin channel. |
5717 | */ |
5718 | override_value = 0; |
5719 | if (ssh_throttled_all) |
5720 | override_value = ssh_overall_bufsize; |
5721 | |
5722 | if (ssh_version == 1) { |
5723 | return override_value; |
5724 | } else if (ssh_version == 2) { |
5725 | if (!mainchan || mainchan->closes > 0) |
5726 | return override_value; |
5727 | else |
5728 | return override_value + bufchain_size(&mainchan->v.v2.outbuffer); |
5729 | } |
5730 | |
5731 | return 0; |
374330e2 |
5732 | } |
5733 | |
5734 | /* |
6e48c3fe |
5735 | * Called to set the size of the window from SSH's POV. |
374330e2 |
5736 | */ |
32874aea |
5737 | static void ssh_size(void) |
5738 | { |
374330e2 |
5739 | switch (ssh_state) { |
5740 | case SSH_STATE_BEFORE_SIZE: |
3687d221 |
5741 | case SSH_STATE_PREPACKET: |
21248260 |
5742 | case SSH_STATE_CLOSED: |
374330e2 |
5743 | break; /* do nothing */ |
5744 | case SSH_STATE_INTERMED: |
5745 | size_needed = TRUE; /* buffer for later */ |
5746 | break; |
5747 | case SSH_STATE_SESSION: |
32874aea |
5748 | if (!cfg.nopty) { |
5749 | if (ssh_version == 1) { |
5750 | send_packet(SSH1_CMSG_WINDOW_SIZE, |
5751 | PKT_INT, rows, PKT_INT, cols, |
5752 | PKT_INT, 0, PKT_INT, 0, PKT_END); |
5753 | } else { |
5754 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
5755 | ssh2_pkt_adduint32(mainchan->remoteid); |
5756 | ssh2_pkt_addstring("window-change"); |
5757 | ssh2_pkt_addbool(0); |
5758 | ssh2_pkt_adduint32(cols); |
5759 | ssh2_pkt_adduint32(rows); |
5760 | ssh2_pkt_adduint32(0); |
5761 | ssh2_pkt_adduint32(0); |
5762 | ssh2_pkt_send(); |
5763 | } |
5764 | } |
5765 | break; |
374330e2 |
5766 | } |
5767 | } |
5768 | |
5769 | /* |
6abbf9e3 |
5770 | * Send Telnet special codes. TS_EOF is useful for `plink', so you |
5771 | * can send an EOF and collect resulting output (e.g. `plink |
5772 | * hostname sort'). |
374330e2 |
5773 | */ |
32874aea |
5774 | static void ssh_special(Telnet_Special code) |
5775 | { |
6abbf9e3 |
5776 | if (code == TS_EOF) { |
32874aea |
5777 | if (ssh_state != SSH_STATE_SESSION) { |
5778 | /* |
5779 | * Buffer the EOF in case we are pre-SESSION, so we can |
5780 | * send it as soon as we reach SESSION. |
5781 | */ |
5782 | if (code == TS_EOF) |
5783 | eof_needed = TRUE; |
5784 | return; |
5785 | } |
5786 | if (ssh_version == 1) { |
5787 | send_packet(SSH1_CMSG_EOF, PKT_END); |
5788 | } else { |
5789 | ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF); |
5790 | ssh2_pkt_adduint32(mainchan->remoteid); |
5791 | ssh2_pkt_send(); |
5792 | } |
5793 | logevent("Sent EOF message"); |
ec55b220 |
5794 | } else if (code == TS_PING) { |
32874aea |
5795 | if (ssh_state == SSH_STATE_CLOSED |
5796 | || ssh_state == SSH_STATE_PREPACKET) return; |
5797 | if (ssh_version == 1) { |
5798 | send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END); |
5799 | } else { |
5800 | ssh2_pkt_init(SSH2_MSG_IGNORE); |
5801 | ssh2_pkt_addstring_start(); |
5802 | ssh2_pkt_send(); |
5803 | } |
6abbf9e3 |
5804 | } else { |
32874aea |
5805 | /* do nothing */ |
6abbf9e3 |
5806 | } |
374330e2 |
5807 | } |
5808 | |
d74d141c |
5809 | void *new_sock_channel(Socket s) |
5810 | { |
5811 | struct ssh_channel *c; |
5812 | c = smalloc(sizeof(struct ssh_channel)); |
5813 | |
5814 | if (c) { |
bc240b21 |
5815 | c->remoteid = -1; /* to be set when open confirmed */ |
d74d141c |
5816 | c->localid = alloc_channel_id(); |
5817 | c->closes = 0; |
bc240b21 |
5818 | c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */ |
d74d141c |
5819 | c->u.pfd.s = s; |
013dd8c0 |
5820 | bufchain_init(&c->v.v2.outbuffer); |
d74d141c |
5821 | add234(ssh_channels, c); |
5822 | } |
5823 | return c; |
5824 | } |
5825 | |
5471d09a |
5826 | /* |
5827 | * This is called when stdout/stderr (the entity to which |
5828 | * from_backend sends data) manages to clear some backlog. |
5829 | */ |
5830 | void ssh_unthrottle(int bufsize) |
5831 | { |
5832 | if (ssh_version == 1) { |
90347b95 |
5833 | if (ssh1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) { |
5471d09a |
5834 | ssh1_stdout_throttling = 0; |
5835 | ssh1_throttle(-1); |
5836 | } |
5837 | } else { |
5838 | if (mainchan && mainchan->closes == 0) |
5839 | ssh2_set_window(mainchan, OUR_V2_WINSIZE - bufsize); |
5840 | } |
5841 | } |
5842 | |
d74d141c |
5843 | void ssh_send_port_open(void *channel, char *hostname, int port, char *org) |
5844 | { |
5845 | struct ssh_channel *c = (struct ssh_channel *)channel; |
5846 | char buf[1024]; |
5847 | |
5848 | sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port); |
5849 | logevent(buf); |
5850 | |
bc240b21 |
5851 | if (ssh_version == 1) { |
5852 | send_packet(SSH1_MSG_PORT_OPEN, |
5853 | PKT_INT, c->localid, |
5854 | PKT_STR, hostname, |
5855 | PKT_INT, port, |
5856 | //PKT_STR, <org:orgport>, |
5857 | PKT_END); |
5858 | } else { |
5859 | ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN); |
5860 | ssh2_pkt_addstring("direct-tcpip"); |
5861 | ssh2_pkt_adduint32(c->localid); |
5471d09a |
5862 | c->v.v2.locwindow = OUR_V2_WINSIZE; |
5863 | ssh2_pkt_adduint32(c->v.v2.locwindow);/* our window size */ |
bc240b21 |
5864 | ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */ |
5865 | ssh2_pkt_addstring(hostname); |
5866 | ssh2_pkt_adduint32(port); |
5867 | /* |
5868 | * We make up values for the originator data; partly it's |
5869 | * too much hassle to keep track, and partly I'm not |
5870 | * convinced the server should be told details like that |
5871 | * about my local network configuration. |
5872 | */ |
5873 | ssh2_pkt_addstring("client-side-connection"); |
5874 | ssh2_pkt_adduint32(0); |
5875 | ssh2_pkt_send(); |
5876 | } |
d74d141c |
5877 | } |
5878 | |
5879 | |
32874aea |
5880 | static Socket ssh_socket(void) |
5881 | { |
5882 | return s; |
5883 | } |
8ccc75b0 |
5884 | |
32874aea |
5885 | static int ssh_sendok(void) |
5886 | { |
5887 | return ssh_send_ok; |
5888 | } |
fb09bf1c |
5889 | |
32874aea |
5890 | static int ssh_ldisc(int option) |
5891 | { |
5892 | if (option == LD_ECHO) |
5893 | return ssh_echoing; |
5894 | if (option == LD_EDIT) |
5895 | return ssh_editing; |
0965bee0 |
5896 | return FALSE; |
5897 | } |
5898 | |
d8d6c7e5 |
5899 | static int ssh_return_exitcode(void) |
5900 | { |
5901 | return ssh_exitcode; |
5902 | } |
5903 | |
374330e2 |
5904 | Backend ssh_backend = { |
5905 | ssh_init, |
374330e2 |
5906 | ssh_send, |
5471d09a |
5907 | ssh_sendbuffer, |
374330e2 |
5908 | ssh_size, |
4017be6d |
5909 | ssh_special, |
8ccc75b0 |
5910 | ssh_socket, |
d8d6c7e5 |
5911 | ssh_return_exitcode, |
97db3be4 |
5912 | ssh_sendok, |
0965bee0 |
5913 | ssh_ldisc, |
5471d09a |
5914 | ssh_unthrottle, |
97db3be4 |
5915 | 22 |
bc240b21 |
5916 | }; |