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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 | #define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \ |
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23 | (s ? sk_close(s), s = NULL : 0), \ |
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24 | connection_fatal msg ) |
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25 | |
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26 | #define SSH1_MSG_DISCONNECT 1 /* 0x1 */ |
27 | #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */ |
28 | #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */ |
29 | #define SSH1_CMSG_USER 4 /* 0x4 */ |
30 | #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */ |
31 | #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */ |
32 | #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */ |
33 | #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */ |
34 | #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */ |
35 | #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */ |
36 | #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */ |
37 | #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */ |
38 | #define SSH1_SMSG_SUCCESS 14 /* 0xe */ |
39 | #define SSH1_SMSG_FAILURE 15 /* 0xf */ |
40 | #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */ |
41 | #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */ |
42 | #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */ |
43 | #define SSH1_CMSG_EOF 19 /* 0x13 */ |
44 | #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */ |
45 | #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */ |
46 | #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */ |
47 | #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */ |
48 | #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */ |
49 | #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */ |
50 | #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */ |
51 | #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */ |
52 | #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */ |
53 | #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */ |
54 | #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */ |
55 | #define SSH1_MSG_IGNORE 32 /* 0x20 */ |
56 | #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */ |
57 | #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */ |
58 | #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */ |
59 | #define SSH1_MSG_DEBUG 36 /* 0x24 */ |
60 | #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */ |
61 | #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */ |
62 | #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */ |
63 | #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */ |
64 | #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */ |
65 | #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */ |
66 | #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */ |
67 | |
68 | #define SSH1_AUTH_TIS 5 /* 0x5 */ |
69 | #define SSH1_AUTH_CCARD 16 /* 0x10 */ |
70 | |
71 | #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */ |
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72 | /* Mask for protoflags we will echo back to server if seen */ |
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73 | #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */ |
74 | |
75 | #define SSH2_MSG_DISCONNECT 1 /* 0x1 */ |
76 | #define SSH2_MSG_IGNORE 2 /* 0x2 */ |
77 | #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */ |
78 | #define SSH2_MSG_DEBUG 4 /* 0x4 */ |
79 | #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */ |
80 | #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */ |
81 | #define SSH2_MSG_KEXINIT 20 /* 0x14 */ |
82 | #define SSH2_MSG_NEWKEYS 21 /* 0x15 */ |
83 | #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */ |
84 | #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */ |
85 | #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */ |
86 | #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */ |
87 | #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */ |
88 | #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */ |
89 | #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */ |
90 | #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */ |
91 | #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */ |
92 | #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */ |
93 | #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */ |
94 | #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */ |
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95 | #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */ |
96 | #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */ |
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97 | #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */ |
98 | #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */ |
99 | #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */ |
100 | #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */ |
101 | #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */ |
102 | #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */ |
103 | #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */ |
104 | #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */ |
105 | #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */ |
106 | #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */ |
107 | #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */ |
108 | #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */ |
109 | #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */ |
110 | #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */ |
111 | |
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112 | /* |
113 | * Packet type contexts, so that ssh2_pkt_type can correctly decode |
114 | * the ambiguous type numbers back into the correct type strings. |
115 | */ |
116 | #define SSH2_PKTCTX_DHGROUP1 0x0001 |
117 | #define SSH2_PKTCTX_DHGEX 0x0002 |
118 | #define SSH2_PKTCTX_PUBLICKEY 0x0010 |
119 | #define SSH2_PKTCTX_PASSWORD 0x0020 |
120 | #define SSH2_PKTCTX_KBDINTER 0x0040 |
121 | #define SSH2_PKTCTX_AUTH_MASK 0x00F0 |
122 | |
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123 | #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */ |
124 | #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */ |
125 | #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */ |
126 | #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */ |
127 | #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */ |
128 | #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */ |
129 | #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */ |
130 | #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */ |
131 | #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */ |
132 | #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */ |
133 | #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */ |
134 | #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */ |
135 | #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */ |
136 | #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */ |
137 | #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */ |
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138 | |
139 | static const char *const ssh2_disconnect_reasons[] = { |
140 | NULL, |
141 | "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT", |
142 | "SSH_DISCONNECT_PROTOCOL_ERROR", |
143 | "SSH_DISCONNECT_KEY_EXCHANGE_FAILED", |
144 | "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED", |
145 | "SSH_DISCONNECT_MAC_ERROR", |
146 | "SSH_DISCONNECT_COMPRESSION_ERROR", |
147 | "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE", |
148 | "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED", |
149 | "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE", |
150 | "SSH_DISCONNECT_CONNECTION_LOST", |
151 | "SSH_DISCONNECT_BY_APPLICATION", |
152 | "SSH_DISCONNECT_TOO_MANY_CONNECTIONS", |
153 | "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER", |
154 | "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE", |
155 | "SSH_DISCONNECT_ILLEGAL_USER_NAME", |
156 | }; |
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157 | |
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158 | #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */ |
159 | #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */ |
160 | #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */ |
161 | #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */ |
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162 | |
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163 | #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */ |
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164 | |
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165 | /* |
166 | * Various remote-bug flags. |
167 | */ |
168 | #define BUG_CHOKES_ON_SSH1_IGNORE 1 |
169 | #define BUG_SSH2_HMAC 2 |
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170 | #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4 |
171 | |
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172 | static int ssh_pkt_ctx = 0; |
173 | |
174 | #define translate(x) if (type == x) return #x |
175 | #define translatec(x,ctx) if (type == x && (ssh_pkt_ctx & ctx)) return #x |
176 | char *ssh1_pkt_type(int type) |
177 | { |
178 | translate(SSH1_MSG_DISCONNECT); |
179 | translate(SSH1_SMSG_PUBLIC_KEY); |
180 | translate(SSH1_CMSG_SESSION_KEY); |
181 | translate(SSH1_CMSG_USER); |
182 | translate(SSH1_CMSG_AUTH_RSA); |
183 | translate(SSH1_SMSG_AUTH_RSA_CHALLENGE); |
184 | translate(SSH1_CMSG_AUTH_RSA_RESPONSE); |
185 | translate(SSH1_CMSG_AUTH_PASSWORD); |
186 | translate(SSH1_CMSG_REQUEST_PTY); |
187 | translate(SSH1_CMSG_WINDOW_SIZE); |
188 | translate(SSH1_CMSG_EXEC_SHELL); |
189 | translate(SSH1_CMSG_EXEC_CMD); |
190 | translate(SSH1_SMSG_SUCCESS); |
191 | translate(SSH1_SMSG_FAILURE); |
192 | translate(SSH1_CMSG_STDIN_DATA); |
193 | translate(SSH1_SMSG_STDOUT_DATA); |
194 | translate(SSH1_SMSG_STDERR_DATA); |
195 | translate(SSH1_CMSG_EOF); |
196 | translate(SSH1_SMSG_EXIT_STATUS); |
197 | translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION); |
198 | translate(SSH1_MSG_CHANNEL_OPEN_FAILURE); |
199 | translate(SSH1_MSG_CHANNEL_DATA); |
200 | translate(SSH1_MSG_CHANNEL_CLOSE); |
201 | translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION); |
202 | translate(SSH1_SMSG_X11_OPEN); |
203 | translate(SSH1_CMSG_PORT_FORWARD_REQUEST); |
204 | translate(SSH1_MSG_PORT_OPEN); |
205 | translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING); |
206 | translate(SSH1_SMSG_AGENT_OPEN); |
207 | translate(SSH1_MSG_IGNORE); |
208 | translate(SSH1_CMSG_EXIT_CONFIRMATION); |
209 | translate(SSH1_CMSG_X11_REQUEST_FORWARDING); |
210 | translate(SSH1_CMSG_AUTH_RHOSTS_RSA); |
211 | translate(SSH1_MSG_DEBUG); |
212 | translate(SSH1_CMSG_REQUEST_COMPRESSION); |
213 | translate(SSH1_CMSG_AUTH_TIS); |
214 | translate(SSH1_SMSG_AUTH_TIS_CHALLENGE); |
215 | translate(SSH1_CMSG_AUTH_TIS_RESPONSE); |
216 | translate(SSH1_CMSG_AUTH_CCARD); |
217 | translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE); |
218 | translate(SSH1_CMSG_AUTH_CCARD_RESPONSE); |
219 | return "unknown"; |
220 | } |
221 | char *ssh2_pkt_type(int type) |
222 | { |
223 | translate(SSH2_MSG_DISCONNECT); |
224 | translate(SSH2_MSG_IGNORE); |
225 | translate(SSH2_MSG_UNIMPLEMENTED); |
226 | translate(SSH2_MSG_DEBUG); |
227 | translate(SSH2_MSG_SERVICE_REQUEST); |
228 | translate(SSH2_MSG_SERVICE_ACCEPT); |
229 | translate(SSH2_MSG_KEXINIT); |
230 | translate(SSH2_MSG_NEWKEYS); |
231 | translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP1); |
232 | translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1); |
233 | translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX); |
234 | translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX); |
235 | translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX); |
236 | translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX); |
237 | translate(SSH2_MSG_USERAUTH_REQUEST); |
238 | translate(SSH2_MSG_USERAUTH_FAILURE); |
239 | translate(SSH2_MSG_USERAUTH_SUCCESS); |
240 | translate(SSH2_MSG_USERAUTH_BANNER); |
241 | translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY); |
242 | translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD); |
243 | translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER); |
244 | translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER); |
245 | translate(SSH2_MSG_GLOBAL_REQUEST); |
246 | translate(SSH2_MSG_REQUEST_SUCCESS); |
247 | translate(SSH2_MSG_REQUEST_FAILURE); |
248 | translate(SSH2_MSG_CHANNEL_OPEN); |
249 | translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); |
250 | translate(SSH2_MSG_CHANNEL_OPEN_FAILURE); |
251 | translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
252 | translate(SSH2_MSG_CHANNEL_DATA); |
253 | translate(SSH2_MSG_CHANNEL_EXTENDED_DATA); |
254 | translate(SSH2_MSG_CHANNEL_EOF); |
255 | translate(SSH2_MSG_CHANNEL_CLOSE); |
256 | translate(SSH2_MSG_CHANNEL_REQUEST); |
257 | translate(SSH2_MSG_CHANNEL_SUCCESS); |
258 | translate(SSH2_MSG_CHANNEL_FAILURE); |
259 | return "unknown"; |
260 | } |
261 | #undef translate |
262 | #undef translatec |
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263 | |
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264 | #define GET_32BIT(cp) \ |
265 | (((unsigned long)(unsigned char)(cp)[0] << 24) | \ |
266 | ((unsigned long)(unsigned char)(cp)[1] << 16) | \ |
267 | ((unsigned long)(unsigned char)(cp)[2] << 8) | \ |
268 | ((unsigned long)(unsigned char)(cp)[3])) |
269 | |
270 | #define PUT_32BIT(cp, value) { \ |
271 | (cp)[0] = (unsigned char)((value) >> 24); \ |
272 | (cp)[1] = (unsigned char)((value) >> 16); \ |
273 | (cp)[2] = (unsigned char)((value) >> 8); \ |
274 | (cp)[3] = (unsigned char)(value); } |
275 | |
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276 | enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM }; |
972a41c8 |
277 | |
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278 | /* Coroutine mechanics for the sillier bits of the code */ |
279 | #define crBegin1 static int crLine = 0; |
280 | #define crBegin2 switch(crLine) { case 0:; |
281 | #define crBegin crBegin1; crBegin2; |
282 | #define crFinish(z) } crLine = 0; return (z) |
283 | #define crFinishV } crLine = 0; return |
284 | #define crReturn(z) \ |
285 | do {\ |
286 | crLine=__LINE__; return (z); case __LINE__:;\ |
287 | } while (0) |
288 | #define crReturnV \ |
289 | do {\ |
290 | crLine=__LINE__; return; case __LINE__:;\ |
291 | } while (0) |
292 | #define crStop(z) do{ crLine = 0; return (z); }while(0) |
293 | #define crStopV do{ crLine = 0; return; }while(0) |
fb09bf1c |
294 | #define crWaitUntil(c) do { crReturn(0); } while (!(c)) |
7cca0d81 |
295 | #define crWaitUntilV(c) do { crReturnV; } while (!(c)) |
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296 | |
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297 | extern char *x11_init(Socket *, char *, void *); |
298 | extern void x11_close(Socket); |
5471d09a |
299 | extern int x11_send(Socket, char *, int); |
9c964e85 |
300 | extern void x11_invent_auth(char *, int, char *, int); |
5471d09a |
301 | extern void x11_unthrottle(Socket s); |
302 | extern void x11_override_throttle(Socket s, int enable); |
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303 | |
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304 | extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c); |
305 | extern char *pfd_addforward(char *desthost, int destport, int port); |
306 | extern void pfd_close(Socket s); |
5471d09a |
307 | extern int pfd_send(Socket s, char *data, int len); |
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308 | extern void pfd_confirm(Socket s); |
5471d09a |
309 | extern void pfd_unthrottle(Socket s); |
310 | extern void pfd_override_throttle(Socket s, int enable); |
311 | |
312 | /* |
313 | * Buffer management constants. There are several of these for |
314 | * various different purposes: |
315 | * |
316 | * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up |
317 | * on a local data stream before we throttle the whole SSH |
318 | * connection (in SSH1 only). Throttling the whole connection is |
319 | * pretty drastic so we set this high in the hope it won't |
320 | * happen very often. |
321 | * |
322 | * - SSH_MAX_BACKLOG is the amount of backlog that must build up |
323 | * on the SSH connection itself before we defensively throttle |
324 | * _all_ local data streams. This is pretty drastic too (though |
325 | * thankfully unlikely in SSH2 since the window mechanism should |
326 | * ensure that the server never has any need to throttle its end |
327 | * of the connection), so we set this high as well. |
328 | * |
329 | * - OUR_V2_WINSIZE is the maximum window size we present on SSH2 |
330 | * channels. |
331 | */ |
332 | |
333 | #define SSH1_BUFFER_LIMIT 32768 |
334 | #define SSH_MAX_BACKLOG 32768 |
335 | #define OUR_V2_WINSIZE 16384 |
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336 | |
a92dd380 |
337 | const static struct ssh_kex *kex_algs[] = { |
a92dd380 |
338 | &ssh_diffiehellman_gex, |
32874aea |
339 | &ssh_diffiehellman |
340 | }; |
e5574168 |
341 | |
85cc02bb |
342 | const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss }; |
e5574168 |
343 | |
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344 | static void nullmac_key(unsigned char *key) |
345 | { |
346 | } |
347 | static void nullmac_generate(unsigned char *blk, int len, |
348 | unsigned long seq) |
349 | { |
350 | } |
351 | static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) |
352 | { |
353 | return 1; |
354 | } |
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355 | const static struct ssh_mac ssh_mac_none = { |
d39f364a |
356 | nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0 |
e5574168 |
357 | }; |
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358 | const static struct ssh_mac *macs[] = { |
32874aea |
359 | &ssh_sha1, &ssh_md5, &ssh_mac_none |
360 | }; |
8b2715b2 |
361 | const static struct ssh_mac *buggymacs[] = { |
32874aea |
362 | &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none |
363 | }; |
e5574168 |
364 | |
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365 | static void ssh_comp_none_init(void) |
366 | { |
367 | } |
4ba9b64b |
368 | static int ssh_comp_none_block(unsigned char *block, int len, |
32874aea |
369 | unsigned char **outblock, int *outlen) |
370 | { |
371 | return 0; |
372 | } |
373 | static int ssh_comp_none_disable(void) |
374 | { |
4ba9b64b |
375 | return 0; |
376 | } |
57476f6b |
377 | const static struct ssh_compress ssh_comp_none = { |
4ba9b64b |
378 | "none", |
379 | ssh_comp_none_init, ssh_comp_none_block, |
63b00c83 |
380 | ssh_comp_none_init, ssh_comp_none_block, |
381 | ssh_comp_none_disable |
e5574168 |
382 | }; |
4ba9b64b |
383 | extern const struct ssh_compress ssh_zlib; |
384 | const static struct ssh_compress *compressions[] = { |
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385 | &ssh_zlib, &ssh_comp_none |
386 | }; |
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387 | |
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388 | enum { /* channel types */ |
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389 | CHAN_MAINSESSION, |
390 | CHAN_X11, |
391 | CHAN_AGENT, |
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392 | CHAN_SOCKDATA, |
393 | CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */ |
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394 | }; |
395 | |
dacbd0e8 |
396 | /* |
397 | * 2-3-4 tree storing channels. |
398 | */ |
399 | struct ssh_channel { |
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400 | unsigned remoteid, localid; |
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401 | int type; |
402 | int closes; |
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403 | union { |
404 | struct ssh1_data_channel { |
405 | int throttling; |
406 | } v1; |
407 | struct ssh2_data_channel { |
408 | bufchain outbuffer; |
409 | unsigned remwindow, remmaxpkt; |
410 | unsigned locwindow; |
411 | } v2; |
412 | } v; |
dacbd0e8 |
413 | union { |
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414 | struct ssh_agent_channel { |
415 | unsigned char *message; |
416 | unsigned char msglen[4]; |
417 | int lensofar, totallen; |
418 | } a; |
419 | struct ssh_x11_channel { |
420 | Socket s; |
421 | } x11; |
d74d141c |
422 | struct ssh_pfd_channel { |
423 | Socket s; |
424 | } pfd; |
dacbd0e8 |
425 | } u; |
426 | }; |
57476f6b |
427 | |
d74d141c |
428 | /* |
bc240b21 |
429 | * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH |
430 | * 2 use this structure in different ways, reflecting SSH 2's |
431 | * altogether saner approach to port forwarding. |
432 | * |
433 | * In SSH 1, you arrange a remote forwarding by sending the server |
434 | * the remote port number, and the local destination host:port. |
435 | * When a connection comes in, the server sends you back that |
436 | * host:port pair, and you connect to it. This is a ready-made |
437 | * security hole if you're not on the ball: a malicious server |
438 | * could send you back _any_ host:port pair, so if you trustingly |
439 | * connect to the address it gives you then you've just opened the |
440 | * entire inside of your corporate network just by connecting |
441 | * through it to a dodgy SSH server. Hence, we must store a list of |
442 | * host:port pairs we _are_ trying to forward to, and reject a |
443 | * connection request from the server if it's not in the list. |
444 | * |
445 | * In SSH 2, each side of the connection minds its own business and |
446 | * doesn't send unnecessary information to the other. You arrange a |
447 | * remote forwarding by sending the server just the remote port |
448 | * number. When a connection comes in, the server tells you which |
449 | * of its ports was connected to; and _you_ have to remember what |
450 | * local host:port pair went with that port number. |
451 | * |
452 | * Hence: in SSH 1 this structure stores host:port pairs we intend |
453 | * to allow connections to, and is indexed by those host:port |
454 | * pairs. In SSH 2 it stores a mapping from source port to |
455 | * destination host:port pair, and is indexed by source port. |
d74d141c |
456 | */ |
457 | struct ssh_rportfwd { |
bc240b21 |
458 | unsigned sport, dport; |
459 | char dhost[256]; |
d74d141c |
460 | }; |
461 | |
57476f6b |
462 | struct Packet { |
463 | long length; |
464 | int type; |
465 | unsigned char *data; |
466 | unsigned char *body; |
467 | long savedpos; |
468 | long maxlen; |
469 | }; |
470 | |
0db56f73 |
471 | static SHA_State exhash, exhashbase; |
57476f6b |
472 | |
8df7a775 |
473 | static Socket s = NULL; |
57476f6b |
474 | |
475 | static unsigned char session_key[32]; |
4ba9b64b |
476 | static int ssh1_compressing; |
b96dc54c |
477 | static int ssh1_remote_protoflags; |
478 | static int ssh1_local_protoflags; |
db7d555c |
479 | static int ssh_agentfwd_enabled; |
9c964e85 |
480 | static int ssh_X11_fwd_enabled; |
7d503c31 |
481 | static int ssh_remote_bugs; |
57476f6b |
482 | static const struct ssh_cipher *cipher = NULL; |
0a3f1d48 |
483 | static const struct ssh2_cipher *cscipher = NULL; |
484 | static const struct ssh2_cipher *sccipher = NULL; |
57476f6b |
485 | static const struct ssh_mac *csmac = NULL; |
486 | static const struct ssh_mac *scmac = NULL; |
487 | static const struct ssh_compress *cscomp = NULL; |
488 | static const struct ssh_compress *sccomp = NULL; |
489 | static const struct ssh_kex *kex = NULL; |
e055a386 |
490 | static const struct ssh_signkey *hostkey = NULL; |
65a22376 |
491 | static unsigned char ssh2_session_id[20]; |
32874aea |
492 | int (*ssh_get_line) (const char *prompt, char *str, int maxlen, |
493 | int is_pw) = NULL; |
57476f6b |
494 | |
495 | static char *savedhost; |
496 | static int savedport; |
497 | static int ssh_send_ok; |
0965bee0 |
498 | static int ssh_echoing, ssh_editing; |
57476f6b |
499 | |
32874aea |
500 | static tree234 *ssh_channels; /* indexed by local id */ |
57476f6b |
501 | static struct ssh_channel *mainchan; /* primary session channel */ |
502 | |
d74d141c |
503 | static tree234 *ssh_rportfwds; |
504 | |
57476f6b |
505 | static enum { |
3687d221 |
506 | SSH_STATE_PREPACKET, |
57476f6b |
507 | SSH_STATE_BEFORE_SIZE, |
508 | SSH_STATE_INTERMED, |
509 | SSH_STATE_SESSION, |
510 | SSH_STATE_CLOSED |
3687d221 |
511 | } ssh_state = SSH_STATE_PREPACKET; |
57476f6b |
512 | |
3687d221 |
513 | static int size_needed = FALSE, eof_needed = FALSE; |
57476f6b |
514 | |
515 | static struct Packet pktin = { 0, 0, NULL, NULL, 0 }; |
516 | static struct Packet pktout = { 0, 0, NULL, NULL, 0 }; |
b185170a |
517 | static unsigned char *deferred_send_data = NULL; |
518 | static int deferred_len = 0, deferred_size = 0; |
57476f6b |
519 | |
fd5e5847 |
520 | /* |
521 | * Gross hack: pscp will try to start SFTP but fall back to scp1 if |
522 | * that fails. This variable is the means by which scp.c can reach |
523 | * into the SSH code and find out which one it got. |
524 | */ |
525 | int ssh_fallback_cmd = 0; |
526 | |
57476f6b |
527 | static int ssh_version; |
5471d09a |
528 | static int ssh1_throttle_count; |
529 | static int ssh_overall_bufsize; |
530 | static int ssh_throttled_all; |
531 | static int ssh1_stdout_throttling; |
32874aea |
532 | static void (*ssh_protocol) (unsigned char *in, int inlen, int ispkt); |
57476f6b |
533 | static void ssh1_protocol(unsigned char *in, int inlen, int ispkt); |
534 | static void ssh2_protocol(unsigned char *in, int inlen, int ispkt); |
535 | static void ssh_size(void); |
32874aea |
536 | static void ssh_special(Telnet_Special); |
5471d09a |
537 | static int ssh2_try_send(struct ssh_channel *c); |
32874aea |
538 | static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, |
539 | int len); |
5471d09a |
540 | static void ssh_throttle_all(int enable, int bufsize); |
541 | static void ssh2_set_window(struct ssh_channel *c, unsigned newwin); |
32874aea |
542 | static int (*s_rdpkt) (unsigned char **data, int *datalen); |
5471d09a |
543 | static int ssh_sendbuffer(void); |
57476f6b |
544 | |
545 | static struct rdpkt1_state_tag { |
546 | long len, pad, biglen, to_read; |
547 | unsigned long realcrc, gotcrc; |
548 | unsigned char *p; |
549 | int i; |
550 | int chunk; |
551 | } rdpkt1_state; |
552 | |
960e736a |
553 | static struct rdpkt2_state_tag { |
554 | long len, pad, payload, packetlen, maclen; |
555 | int i; |
556 | int cipherblk; |
557 | unsigned long incoming_sequence; |
558 | } rdpkt2_state; |
559 | |
32874aea |
560 | static int ssh_channelcmp(void *av, void *bv) |
561 | { |
562 | struct ssh_channel *a = (struct ssh_channel *) av; |
563 | struct ssh_channel *b = (struct ssh_channel *) bv; |
564 | if (a->localid < b->localid) |
565 | return -1; |
566 | if (a->localid > b->localid) |
567 | return +1; |
dacbd0e8 |
568 | return 0; |
569 | } |
32874aea |
570 | static int ssh_channelfind(void *av, void *bv) |
571 | { |
572 | unsigned *a = (unsigned *) av; |
573 | struct ssh_channel *b = (struct ssh_channel *) bv; |
574 | if (*a < b->localid) |
575 | return -1; |
576 | if (*a > b->localid) |
577 | return +1; |
dacbd0e8 |
578 | return 0; |
579 | } |
580 | |
bc240b21 |
581 | static int ssh_rportcmp_ssh1(void *av, void *bv) |
d74d141c |
582 | { |
583 | struct ssh_rportfwd *a = (struct ssh_rportfwd *) av; |
584 | struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv; |
585 | int i; |
bc240b21 |
586 | if ( (i = strcmp(a->dhost, b->dhost)) != 0) |
d74d141c |
587 | return i < 0 ? -1 : +1; |
bc240b21 |
588 | if (a->dport > b->dport) |
589 | return +1; |
590 | if (a->dport < b->dport) |
591 | return -1; |
592 | return 0; |
593 | } |
594 | |
595 | static int ssh_rportcmp_ssh2(void *av, void *bv) |
596 | { |
597 | struct ssh_rportfwd *a = (struct ssh_rportfwd *) av; |
598 | struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv; |
cdcbdf3b |
599 | |
bc240b21 |
600 | if (a->sport > b->sport) |
d74d141c |
601 | return +1; |
bc240b21 |
602 | if (a->sport < b->sport) |
603 | return -1; |
d74d141c |
604 | return 0; |
605 | } |
606 | |
32874aea |
607 | static int alloc_channel_id(void) |
608 | { |
260f3dec |
609 | const unsigned CHANNEL_NUMBER_OFFSET = 256; |
610 | unsigned low, high, mid; |
d2371c81 |
611 | int tsize; |
612 | struct ssh_channel *c; |
613 | |
614 | /* |
615 | * First-fit allocation of channel numbers: always pick the |
616 | * lowest unused one. To do this, binary-search using the |
617 | * counted B-tree to find the largest channel ID which is in a |
618 | * contiguous sequence from the beginning. (Precisely |
619 | * everything in that sequence must have ID equal to its tree |
620 | * index plus CHANNEL_NUMBER_OFFSET.) |
621 | */ |
622 | tsize = count234(ssh_channels); |
623 | |
32874aea |
624 | low = -1; |
625 | high = tsize; |
d2371c81 |
626 | while (high - low > 1) { |
627 | mid = (high + low) / 2; |
628 | c = index234(ssh_channels, mid); |
629 | if (c->localid == mid + CHANNEL_NUMBER_OFFSET) |
630 | low = mid; /* this one is fine */ |
631 | else |
632 | high = mid; /* this one is past it */ |
633 | } |
634 | /* |
635 | * Now low points to either -1, or the tree index of the |
636 | * largest ID in the initial sequence. |
637 | */ |
638 | { |
639 | unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET; |
640 | assert(NULL == find234(ssh_channels, &i, ssh_channelfind)); |
641 | } |
642 | return low + 1 + CHANNEL_NUMBER_OFFSET; |
643 | } |
644 | |
32874aea |
645 | static void c_write(char *buf, int len) |
646 | { |
67779be7 |
647 | if ((flags & FLAG_STDERR)) { |
32874aea |
648 | int i; |
649 | for (i = 0; i < len; i++) |
650 | if (buf[i] != '\r') |
651 | fputc(buf[i], stderr); |
fb09bf1c |
652 | return; |
653 | } |
fe50e814 |
654 | from_backend(1, buf, len); |
3bdaf79d |
655 | } |
656 | |
32874aea |
657 | static void c_write_untrusted(char *buf, int len) |
658 | { |
a209e957 |
659 | int i; |
660 | for (i = 0; i < len; i++) { |
32874aea |
661 | if (buf[i] == '\n') |
662 | c_write("\r\n", 2); |
663 | else if ((buf[i] & 0x60) || (buf[i] == '\r')) |
664 | c_write(buf + i, 1); |
a209e957 |
665 | } |
666 | } |
667 | |
32874aea |
668 | static void c_write_str(char *buf) |
669 | { |
1408a877 |
670 | c_write(buf, strlen(buf)); |
671 | } |
672 | |
fb09bf1c |
673 | /* |
674 | * Collect incoming data in the incoming packet buffer. |
e5574168 |
675 | * Decipher and verify the packet when it is completely read. |
676 | * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets. |
fb09bf1c |
677 | * Update the *data and *datalen variables. |
678 | * Return the additional nr of bytes needed, or 0 when |
679 | * a complete packet is available. |
680 | */ |
e5574168 |
681 | static int ssh1_rdpkt(unsigned char **data, int *datalen) |
fb09bf1c |
682 | { |
57476f6b |
683 | struct rdpkt1_state_tag *st = &rdpkt1_state; |
374330e2 |
684 | |
685 | crBegin; |
374330e2 |
686 | |
32874aea |
687 | next_packet: |
37508af4 |
688 | |
fb09bf1c |
689 | pktin.type = 0; |
690 | pktin.length = 0; |
374330e2 |
691 | |
57476f6b |
692 | for (st->i = st->len = 0; st->i < 4; st->i++) { |
fb09bf1c |
693 | while ((*datalen) == 0) |
32874aea |
694 | crReturn(4 - st->i); |
57476f6b |
695 | st->len = (st->len << 8) + **data; |
fb09bf1c |
696 | (*data)++, (*datalen)--; |
697 | } |
374330e2 |
698 | |
57476f6b |
699 | st->pad = 8 - (st->len % 8); |
700 | st->biglen = st->len + st->pad; |
701 | pktin.length = st->len - 5; |
fb09bf1c |
702 | |
57476f6b |
703 | if (pktin.maxlen < st->biglen) { |
704 | pktin.maxlen = st->biglen; |
32874aea |
705 | pktin.data = (pktin.data == NULL ? smalloc(st->biglen + APIEXTRA) : |
706 | srealloc(pktin.data, st->biglen + APIEXTRA)); |
fb09bf1c |
707 | if (!pktin.data) |
708 | fatalbox("Out of memory"); |
709 | } |
374330e2 |
710 | |
57476f6b |
711 | st->to_read = st->biglen; |
712 | st->p = pktin.data; |
713 | while (st->to_read > 0) { |
32874aea |
714 | st->chunk = st->to_read; |
fb09bf1c |
715 | while ((*datalen) == 0) |
57476f6b |
716 | crReturn(st->to_read); |
717 | if (st->chunk > (*datalen)) |
718 | st->chunk = (*datalen); |
719 | memcpy(st->p, *data, st->chunk); |
720 | *data += st->chunk; |
721 | *datalen -= st->chunk; |
722 | st->p += st->chunk; |
723 | st->to_read -= st->chunk; |
fb09bf1c |
724 | } |
374330e2 |
725 | |
fb09bf1c |
726 | if (cipher) |
57476f6b |
727 | cipher->decrypt(pktin.data, st->biglen); |
374330e2 |
728 | |
32874aea |
729 | st->realcrc = crc32(pktin.data, st->biglen - 4); |
730 | st->gotcrc = GET_32BIT(pktin.data + st->biglen - 4); |
57476f6b |
731 | if (st->gotcrc != st->realcrc) { |
8d5de777 |
732 | bombout(("Incorrect CRC received on packet")); |
32874aea |
733 | crReturn(0); |
fb09bf1c |
734 | } |
572f871e |
735 | |
4ba9b64b |
736 | pktin.body = pktin.data + st->pad + 1; |
737 | |
738 | if (ssh1_compressing) { |
739 | unsigned char *decompblk; |
740 | int decomplen; |
32874aea |
741 | zlib_decompress_block(pktin.body - 1, pktin.length + 1, |
4ba9b64b |
742 | &decompblk, &decomplen); |
743 | |
744 | if (pktin.maxlen < st->pad + decomplen) { |
745 | pktin.maxlen = st->pad + decomplen; |
32874aea |
746 | pktin.data = srealloc(pktin.data, pktin.maxlen + APIEXTRA); |
747 | pktin.body = pktin.data + st->pad + 1; |
4ba9b64b |
748 | if (!pktin.data) |
749 | fatalbox("Out of memory"); |
750 | } |
751 | |
32874aea |
752 | memcpy(pktin.body - 1, decompblk, decomplen); |
dcbde236 |
753 | sfree(decompblk); |
32874aea |
754 | pktin.length = decomplen - 1; |
4ba9b64b |
755 | } |
756 | |
00db133f |
757 | pktin.type = pktin.body[-1]; |
758 | |
759 | log_packet(PKT_INCOMING, pktin.type, ssh1_pkt_type(pktin.type), |
760 | pktin.body, pktin.length); |
761 | |
e5574168 |
762 | if (pktin.type == SSH1_SMSG_STDOUT_DATA || |
32874aea |
763 | pktin.type == SSH1_SMSG_STDERR_DATA || |
764 | pktin.type == SSH1_MSG_DEBUG || |
765 | pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE || |
766 | pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) { |
fb09bf1c |
767 | long strlen = GET_32BIT(pktin.body); |
8d5de777 |
768 | if (strlen + 4 != pktin.length) { |
769 | bombout(("Received data packet with bogus string length")); |
32874aea |
770 | crReturn(0); |
771 | } |
fb09bf1c |
772 | } |
773 | |
e5574168 |
774 | if (pktin.type == SSH1_MSG_DEBUG) { |
fb09bf1c |
775 | /* log debug message */ |
776 | char buf[80]; |
777 | int strlen = GET_32BIT(pktin.body); |
778 | strcpy(buf, "Remote: "); |
32874aea |
779 | if (strlen > 70) |
780 | strlen = 70; |
781 | memcpy(buf + 8, pktin.body + 4, strlen); |
782 | buf[8 + strlen] = '\0'; |
fb09bf1c |
783 | logevent(buf); |
784 | goto next_packet; |
e5574168 |
785 | } else if (pktin.type == SSH1_MSG_IGNORE) { |
fb09bf1c |
786 | /* do nothing */ |
787 | goto next_packet; |
788 | } |
789 | |
38c4a8da |
790 | if (pktin.type == SSH1_MSG_DISCONNECT) { |
791 | /* log reason code in disconnect message */ |
792 | char buf[256]; |
260f3dec |
793 | unsigned msglen = GET_32BIT(pktin.body); |
794 | unsigned nowlen; |
38c4a8da |
795 | strcpy(buf, "Remote sent disconnect: "); |
796 | nowlen = strlen(buf); |
32874aea |
797 | if (msglen > sizeof(buf) - nowlen - 1) |
798 | msglen = sizeof(buf) - nowlen - 1; |
799 | memcpy(buf + nowlen, pktin.body + 4, msglen); |
800 | buf[nowlen + msglen] = '\0'; |
38c4a8da |
801 | logevent(buf); |
4eb195cc |
802 | bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen)); |
e14d0f19 |
803 | crReturn(0); |
38c4a8da |
804 | } |
805 | |
fb09bf1c |
806 | crFinish(0); |
807 | } |
808 | |
e5574168 |
809 | static int ssh2_rdpkt(unsigned char **data, int *datalen) |
810 | { |
960e736a |
811 | struct rdpkt2_state_tag *st = &rdpkt2_state; |
e5574168 |
812 | |
813 | crBegin; |
814 | |
32874aea |
815 | next_packet: |
e5574168 |
816 | pktin.type = 0; |
817 | pktin.length = 0; |
960e736a |
818 | if (sccipher) |
32874aea |
819 | st->cipherblk = sccipher->blksize; |
e5574168 |
820 | else |
32874aea |
821 | st->cipherblk = 8; |
960e736a |
822 | if (st->cipherblk < 8) |
32874aea |
823 | st->cipherblk = 8; |
960e736a |
824 | |
825 | if (pktin.maxlen < st->cipherblk) { |
826 | pktin.maxlen = st->cipherblk; |
32874aea |
827 | pktin.data = |
828 | (pktin.data == |
829 | NULL ? smalloc(st->cipherblk + |
830 | APIEXTRA) : srealloc(pktin.data, |
831 | st->cipherblk + |
832 | APIEXTRA)); |
e5574168 |
833 | if (!pktin.data) |
834 | fatalbox("Out of memory"); |
835 | } |
836 | |
837 | /* |
838 | * Acquire and decrypt the first block of the packet. This will |
839 | * contain the length and padding details. |
840 | */ |
32874aea |
841 | for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) { |
e5574168 |
842 | while ((*datalen) == 0) |
32874aea |
843 | crReturn(st->cipherblk - st->i); |
960e736a |
844 | pktin.data[st->i] = *(*data)++; |
32874aea |
845 | (*datalen)--; |
e5574168 |
846 | } |
4252c9cc |
847 | |
e5574168 |
848 | if (sccipher) |
32874aea |
849 | sccipher->decrypt(pktin.data, st->cipherblk); |
e5574168 |
850 | |
851 | /* |
852 | * Now get the length and padding figures. |
853 | */ |
960e736a |
854 | st->len = GET_32BIT(pktin.data); |
855 | st->pad = pktin.data[4]; |
e5574168 |
856 | |
857 | /* |
858 | * This enables us to deduce the payload length. |
859 | */ |
960e736a |
860 | st->payload = st->len - st->pad - 1; |
e5574168 |
861 | |
960e736a |
862 | pktin.length = st->payload + 5; |
e5574168 |
863 | |
864 | /* |
865 | * So now we can work out the total packet length. |
866 | */ |
960e736a |
867 | st->packetlen = st->len + 4; |
868 | st->maclen = scmac ? scmac->len : 0; |
e5574168 |
869 | |
870 | /* |
871 | * Adjust memory allocation if packet is too big. |
872 | */ |
32874aea |
873 | if (pktin.maxlen < st->packetlen + st->maclen) { |
874 | pktin.maxlen = st->packetlen + st->maclen; |
875 | pktin.data = |
876 | (pktin.data == |
877 | NULL ? smalloc(pktin.maxlen + APIEXTRA) : srealloc(pktin.data, |
878 | pktin.maxlen |
879 | + |
880 | APIEXTRA)); |
e5574168 |
881 | if (!pktin.data) |
882 | fatalbox("Out of memory"); |
883 | } |
884 | |
885 | /* |
886 | * Read and decrypt the remainder of the packet. |
887 | */ |
32874aea |
888 | for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; |
889 | st->i++) { |
e5574168 |
890 | while ((*datalen) == 0) |
960e736a |
891 | crReturn(st->packetlen + st->maclen - st->i); |
892 | pktin.data[st->i] = *(*data)++; |
32874aea |
893 | (*datalen)--; |
e5574168 |
894 | } |
895 | /* Decrypt everything _except_ the MAC. */ |
896 | if (sccipher) |
32874aea |
897 | sccipher->decrypt(pktin.data + st->cipherblk, |
898 | st->packetlen - st->cipherblk); |
e5574168 |
899 | |
900 | /* |
901 | * Check the MAC. |
902 | */ |
32874aea |
903 | if (scmac |
904 | && !scmac->verify(pktin.data, st->len + 4, |
905 | st->incoming_sequence)) { |
8d5de777 |
906 | bombout(("Incorrect MAC received on packet")); |
32874aea |
907 | crReturn(0); |
8d5de777 |
908 | } |
32874aea |
909 | st->incoming_sequence++; /* whether or not we MACed */ |
e5574168 |
910 | |
4ba9b64b |
911 | /* |
912 | * Decompress packet payload. |
913 | */ |
914 | { |
915 | unsigned char *newpayload; |
916 | int newlen; |
32874aea |
917 | if (sccomp && sccomp->decompress(pktin.data + 5, pktin.length - 5, |
4ba9b64b |
918 | &newpayload, &newlen)) { |
32874aea |
919 | if (pktin.maxlen < newlen + 5) { |
920 | pktin.maxlen = newlen + 5; |
921 | pktin.data = |
922 | (pktin.data == |
923 | NULL ? smalloc(pktin.maxlen + |
924 | APIEXTRA) : srealloc(pktin.data, |
925 | pktin.maxlen + |
926 | APIEXTRA)); |
4ba9b64b |
927 | if (!pktin.data) |
928 | fatalbox("Out of memory"); |
929 | } |
930 | pktin.length = 5 + newlen; |
32874aea |
931 | memcpy(pktin.data + 5, newpayload, newlen); |
dcbde236 |
932 | sfree(newpayload); |
4ba9b64b |
933 | } |
934 | } |
935 | |
e5574168 |
936 | pktin.savedpos = 6; |
937 | pktin.type = pktin.data[5]; |
e5574168 |
938 | |
00db133f |
939 | log_packet(PKT_INCOMING, pktin.type, ssh2_pkt_type(pktin.type), |
940 | pktin.data+6, pktin.length-6); |
941 | |
7cca0d81 |
942 | if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG) |
32874aea |
943 | goto next_packet; /* FIXME: print DEBUG message */ |
e5574168 |
944 | |
38c4a8da |
945 | if (pktin.type == SSH2_MSG_DISCONNECT) { |
946 | /* log reason code in disconnect message */ |
947 | char buf[256]; |
32874aea |
948 | int reason = GET_32BIT(pktin.data + 6); |
949 | unsigned msglen = GET_32BIT(pktin.data + 10); |
260f3dec |
950 | unsigned nowlen; |
38c4a8da |
951 | if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) { |
952 | sprintf(buf, "Received disconnect message (%s)", |
953 | ssh2_disconnect_reasons[reason]); |
954 | } else { |
32874aea |
955 | sprintf(buf, "Received disconnect message (unknown type %d)", |
956 | reason); |
38c4a8da |
957 | } |
958 | logevent(buf); |
959 | strcpy(buf, "Disconnection message text: "); |
960 | nowlen = strlen(buf); |
32874aea |
961 | if (msglen > sizeof(buf) - nowlen - 1) |
962 | msglen = sizeof(buf) - nowlen - 1; |
963 | memcpy(buf + nowlen, pktin.data + 14, msglen); |
964 | buf[nowlen + msglen] = '\0'; |
38c4a8da |
965 | logevent(buf); |
4eb195cc |
966 | bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"", |
967 | reason, |
968 | (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ? |
969 | ssh2_disconnect_reasons[reason] : "unknown", |
970 | buf+nowlen)); |
e14d0f19 |
971 | crReturn(0); |
38c4a8da |
972 | } |
973 | |
e5574168 |
974 | crFinish(0); |
975 | } |
976 | |
32874aea |
977 | static void ssh1_pktout_size(int len) |
978 | { |
374330e2 |
979 | int pad, biglen; |
980 | |
981 | len += 5; /* type and CRC */ |
32874aea |
982 | pad = 8 - (len % 8); |
374330e2 |
983 | biglen = len + pad; |
984 | |
32874aea |
985 | pktout.length = len - 5; |
374330e2 |
986 | if (pktout.maxlen < biglen) { |
987 | pktout.maxlen = biglen; |
8f203108 |
988 | #ifdef MSCRYPTOAPI |
fb09bf1c |
989 | /* Allocate enough buffer space for extra block |
8f203108 |
990 | * for MS CryptEncrypt() */ |
32874aea |
991 | pktout.data = (pktout.data == NULL ? smalloc(biglen + 12) : |
992 | srealloc(pktout.data, biglen + 12)); |
8f203108 |
993 | #else |
32874aea |
994 | pktout.data = (pktout.data == NULL ? smalloc(biglen + 4) : |
995 | srealloc(pktout.data, biglen + 4)); |
8f203108 |
996 | #endif |
374330e2 |
997 | if (!pktout.data) |
998 | fatalbox("Out of memory"); |
999 | } |
32874aea |
1000 | pktout.body = pktout.data + 4 + pad + 1; |
4ba9b64b |
1001 | } |
374330e2 |
1002 | |
32874aea |
1003 | static void s_wrpkt_start(int type, int len) |
1004 | { |
4ba9b64b |
1005 | ssh1_pktout_size(len); |
374330e2 |
1006 | pktout.type = type; |
374330e2 |
1007 | } |
1008 | |
32874aea |
1009 | static int s_wrpkt_prepare(void) |
1010 | { |
374330e2 |
1011 | int pad, len, biglen, i; |
1012 | unsigned long crc; |
1013 | |
4ba9b64b |
1014 | pktout.body[-1] = pktout.type; |
1015 | |
00db133f |
1016 | log_packet(PKT_OUTGOING, pktout.type, ssh1_pkt_type(pktout.type), |
1017 | pktout.body, pktout.length); |
1018 | |
4ba9b64b |
1019 | if (ssh1_compressing) { |
1020 | unsigned char *compblk; |
1021 | int complen; |
32874aea |
1022 | zlib_compress_block(pktout.body - 1, pktout.length + 1, |
4ba9b64b |
1023 | &compblk, &complen); |
32874aea |
1024 | ssh1_pktout_size(complen - 1); |
1025 | memcpy(pktout.body - 1, compblk, complen); |
dcbde236 |
1026 | sfree(compblk); |
4ba9b64b |
1027 | } |
1028 | |
374330e2 |
1029 | len = pktout.length + 5; /* type and CRC */ |
32874aea |
1030 | pad = 8 - (len % 8); |
374330e2 |
1031 | biglen = len + pad; |
1032 | |
32874aea |
1033 | for (i = 0; i < pad; i++) |
1034 | pktout.data[i + 4] = random_byte(); |
1035 | crc = crc32(pktout.data + 4, biglen - 4); |
1036 | PUT_32BIT(pktout.data + biglen, crc); |
fb09bf1c |
1037 | PUT_32BIT(pktout.data, len); |
374330e2 |
1038 | |
1039 | if (cipher) |
32874aea |
1040 | cipher->encrypt(pktout.data + 4, biglen); |
374330e2 |
1041 | |
32874aea |
1042 | return biglen + 4; |
39065bed |
1043 | } |
1044 | |
32874aea |
1045 | static void s_wrpkt(void) |
1046 | { |
5471d09a |
1047 | int len, backlog; |
39065bed |
1048 | len = s_wrpkt_prepare(); |
5471d09a |
1049 | backlog = sk_write(s, pktout.data, len); |
1050 | if (backlog > SSH_MAX_BACKLOG) |
1051 | ssh_throttle_all(1, backlog); |
39065bed |
1052 | } |
1053 | |
32874aea |
1054 | static void s_wrpkt_defer(void) |
1055 | { |
39065bed |
1056 | int len; |
1057 | len = s_wrpkt_prepare(); |
1058 | if (deferred_len + len > deferred_size) { |
32874aea |
1059 | deferred_size = deferred_len + len + 128; |
1060 | deferred_send_data = srealloc(deferred_send_data, deferred_size); |
39065bed |
1061 | } |
32874aea |
1062 | memcpy(deferred_send_data + deferred_len, pktout.data, len); |
39065bed |
1063 | deferred_len += len; |
374330e2 |
1064 | } |
1065 | |
fb09bf1c |
1066 | /* |
39065bed |
1067 | * Construct a packet with the specified contents. |
fb09bf1c |
1068 | */ |
39065bed |
1069 | static void construct_packet(int pkttype, va_list ap1, va_list ap2) |
fb09bf1c |
1070 | { |
fb09bf1c |
1071 | unsigned char *p, *argp, argchar; |
1072 | unsigned long argint; |
1073 | int pktlen, argtype, arglen; |
7cca0d81 |
1074 | Bignum bn; |
fb09bf1c |
1075 | |
1076 | pktlen = 0; |
39065bed |
1077 | while ((argtype = va_arg(ap1, int)) != PKT_END) { |
fb09bf1c |
1078 | switch (argtype) { |
1079 | case PKT_INT: |
39065bed |
1080 | (void) va_arg(ap1, int); |
fb09bf1c |
1081 | pktlen += 4; |
1082 | break; |
1083 | case PKT_CHAR: |
39065bed |
1084 | (void) va_arg(ap1, char); |
fb09bf1c |
1085 | pktlen++; |
1086 | break; |
1087 | case PKT_DATA: |
39065bed |
1088 | (void) va_arg(ap1, unsigned char *); |
1089 | arglen = va_arg(ap1, int); |
fb09bf1c |
1090 | pktlen += arglen; |
1091 | break; |
1092 | case PKT_STR: |
39065bed |
1093 | argp = va_arg(ap1, unsigned char *); |
fb09bf1c |
1094 | arglen = strlen(argp); |
1095 | pktlen += 4 + arglen; |
1096 | break; |
7cca0d81 |
1097 | case PKT_BIGNUM: |
39065bed |
1098 | bn = va_arg(ap1, Bignum); |
32874aea |
1099 | pktlen += ssh1_bignum_length(bn); |
7cca0d81 |
1100 | break; |
fb09bf1c |
1101 | default: |
1102 | assert(0); |
1103 | } |
1104 | } |
fb09bf1c |
1105 | |
1106 | s_wrpkt_start(pkttype, pktlen); |
1107 | p = pktout.body; |
1108 | |
39065bed |
1109 | while ((argtype = va_arg(ap2, int)) != PKT_END) { |
fb09bf1c |
1110 | switch (argtype) { |
1111 | case PKT_INT: |
39065bed |
1112 | argint = va_arg(ap2, int); |
fb09bf1c |
1113 | PUT_32BIT(p, argint); |
1114 | p += 4; |
1115 | break; |
1116 | case PKT_CHAR: |
39065bed |
1117 | argchar = va_arg(ap2, unsigned char); |
fb09bf1c |
1118 | *p = argchar; |
1119 | p++; |
1120 | break; |
1121 | case PKT_DATA: |
39065bed |
1122 | argp = va_arg(ap2, unsigned char *); |
1123 | arglen = va_arg(ap2, int); |
fb09bf1c |
1124 | memcpy(p, argp, arglen); |
1125 | p += arglen; |
1126 | break; |
1127 | case PKT_STR: |
39065bed |
1128 | argp = va_arg(ap2, unsigned char *); |
fb09bf1c |
1129 | arglen = strlen(argp); |
1130 | PUT_32BIT(p, arglen); |
1131 | memcpy(p + 4, argp, arglen); |
1132 | p += 4 + arglen; |
1133 | break; |
7cca0d81 |
1134 | case PKT_BIGNUM: |
39065bed |
1135 | bn = va_arg(ap2, Bignum); |
32874aea |
1136 | p += ssh1_write_bignum(p, bn); |
7cca0d81 |
1137 | break; |
fb09bf1c |
1138 | } |
1139 | } |
39065bed |
1140 | } |
fb09bf1c |
1141 | |
32874aea |
1142 | static void send_packet(int pkttype, ...) |
1143 | { |
39065bed |
1144 | va_list ap1, ap2; |
1145 | va_start(ap1, pkttype); |
1146 | va_start(ap2, pkttype); |
1147 | construct_packet(pkttype, ap1, ap2); |
fb09bf1c |
1148 | s_wrpkt(); |
1149 | } |
1150 | |
32874aea |
1151 | static void defer_packet(int pkttype, ...) |
1152 | { |
39065bed |
1153 | va_list ap1, ap2; |
1154 | va_start(ap1, pkttype); |
1155 | va_start(ap2, pkttype); |
1156 | construct_packet(pkttype, ap1, ap2); |
1157 | s_wrpkt_defer(); |
1158 | } |
1159 | |
32874aea |
1160 | static int ssh_versioncmp(char *a, char *b) |
1161 | { |
9697bfd2 |
1162 | char *ae, *be; |
1163 | unsigned long av, bv; |
1164 | |
43aa02a7 |
1165 | av = strtoul(a, &ae, 10); |
1166 | bv = strtoul(b, &be, 10); |
32874aea |
1167 | if (av != bv) |
1168 | return (av < bv ? -1 : +1); |
1169 | if (*ae == '.') |
1170 | ae++; |
1171 | if (*be == '.') |
1172 | be++; |
43aa02a7 |
1173 | av = strtoul(ae, &ae, 10); |
1174 | bv = strtoul(be, &be, 10); |
32874aea |
1175 | if (av != bv) |
1176 | return (av < bv ? -1 : +1); |
9697bfd2 |
1177 | return 0; |
1178 | } |
1179 | |
e5574168 |
1180 | |
1181 | /* |
a92dd380 |
1182 | * Utility routines for putting an SSH-protocol `string' and |
1183 | * `uint32' into a SHA state. |
e5574168 |
1184 | */ |
1185 | #include <stdio.h> |
32874aea |
1186 | static void sha_string(SHA_State * s, void *str, int len) |
1187 | { |
e5574168 |
1188 | unsigned char lenblk[4]; |
e5574168 |
1189 | PUT_32BIT(lenblk, len); |
e5574168 |
1190 | SHA_Bytes(s, lenblk, 4); |
e5574168 |
1191 | SHA_Bytes(s, str, len); |
1192 | } |
1193 | |
32874aea |
1194 | static void sha_uint32(SHA_State * s, unsigned i) |
1195 | { |
a92dd380 |
1196 | unsigned char intblk[4]; |
1197 | PUT_32BIT(intblk, i); |
1198 | SHA_Bytes(s, intblk, 4); |
1199 | } |
1200 | |
7cca0d81 |
1201 | /* |
1202 | * SSH2 packet construction functions. |
1203 | */ |
32874aea |
1204 | static void ssh2_pkt_ensure(int length) |
1205 | { |
783415f8 |
1206 | if (pktout.maxlen < length) { |
32874aea |
1207 | pktout.maxlen = length + 256; |
1208 | pktout.data = |
1209 | (pktout.data == |
1210 | NULL ? smalloc(pktout.maxlen + |
1211 | APIEXTRA) : srealloc(pktout.data, |
1212 | pktout.maxlen + |
1213 | APIEXTRA)); |
1214 | if (!pktout.data) |
1215 | fatalbox("Out of memory"); |
7cca0d81 |
1216 | } |
783415f8 |
1217 | } |
32874aea |
1218 | static void ssh2_pkt_adddata(void *data, int len) |
1219 | { |
783415f8 |
1220 | pktout.length += len; |
1221 | ssh2_pkt_ensure(pktout.length); |
32874aea |
1222 | memcpy(pktout.data + pktout.length - len, data, len); |
7cca0d81 |
1223 | } |
32874aea |
1224 | static void ssh2_pkt_addbyte(unsigned char byte) |
1225 | { |
7cca0d81 |
1226 | ssh2_pkt_adddata(&byte, 1); |
1227 | } |
32874aea |
1228 | static void ssh2_pkt_init(int pkt_type) |
1229 | { |
7cca0d81 |
1230 | pktout.length = 5; |
32874aea |
1231 | ssh2_pkt_addbyte((unsigned char) pkt_type); |
7cca0d81 |
1232 | } |
32874aea |
1233 | static void ssh2_pkt_addbool(unsigned char value) |
1234 | { |
7cca0d81 |
1235 | ssh2_pkt_adddata(&value, 1); |
1236 | } |
32874aea |
1237 | static void ssh2_pkt_adduint32(unsigned long value) |
1238 | { |
7cca0d81 |
1239 | unsigned char x[4]; |
1240 | PUT_32BIT(x, value); |
1241 | ssh2_pkt_adddata(x, 4); |
1242 | } |
32874aea |
1243 | static void ssh2_pkt_addstring_start(void) |
1244 | { |
7cca0d81 |
1245 | ssh2_pkt_adduint32(0); |
1246 | pktout.savedpos = pktout.length; |
1247 | } |
32874aea |
1248 | static void ssh2_pkt_addstring_str(char *data) |
1249 | { |
7cca0d81 |
1250 | ssh2_pkt_adddata(data, strlen(data)); |
1251 | PUT_32BIT(pktout.data + pktout.savedpos - 4, |
32874aea |
1252 | pktout.length - pktout.savedpos); |
7cca0d81 |
1253 | } |
32874aea |
1254 | static void ssh2_pkt_addstring_data(char *data, int len) |
1255 | { |
7cca0d81 |
1256 | ssh2_pkt_adddata(data, len); |
1257 | PUT_32BIT(pktout.data + pktout.savedpos - 4, |
32874aea |
1258 | pktout.length - pktout.savedpos); |
7cca0d81 |
1259 | } |
32874aea |
1260 | static void ssh2_pkt_addstring(char *data) |
1261 | { |
7cca0d81 |
1262 | ssh2_pkt_addstring_start(); |
1263 | ssh2_pkt_addstring_str(data); |
1264 | } |
32874aea |
1265 | static char *ssh2_mpint_fmt(Bignum b, int *len) |
1266 | { |
7cca0d81 |
1267 | unsigned char *p; |
32874aea |
1268 | int i, n = (bignum_bitcount(b) + 7) / 8; |
3709bfe9 |
1269 | p = smalloc(n + 1); |
7cca0d81 |
1270 | if (!p) |
32874aea |
1271 | fatalbox("out of memory"); |
7cca0d81 |
1272 | p[0] = 0; |
3709bfe9 |
1273 | for (i = 1; i <= n; i++) |
32874aea |
1274 | p[i] = bignum_byte(b, n - i); |
7cca0d81 |
1275 | i = 0; |
32874aea |
1276 | while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0) |
1277 | i++; |
1278 | memmove(p, p + i, n + 1 - i); |
1279 | *len = n + 1 - i; |
7cca0d81 |
1280 | return p; |
1281 | } |
32874aea |
1282 | static void ssh2_pkt_addmp(Bignum b) |
1283 | { |
7cca0d81 |
1284 | unsigned char *p; |
1285 | int len; |
1286 | p = ssh2_mpint_fmt(b, &len); |
1287 | ssh2_pkt_addstring_start(); |
1288 | ssh2_pkt_addstring_data(p, len); |
dcbde236 |
1289 | sfree(p); |
7cca0d81 |
1290 | } |
b185170a |
1291 | |
1292 | /* |
1293 | * Construct an SSH2 final-form packet: compress it, encrypt it, |
1294 | * put the MAC on it. Final packet, ready to be sent, is stored in |
1295 | * pktout.data. Total length is returned. |
1296 | */ |
32874aea |
1297 | static int ssh2_pkt_construct(void) |
1298 | { |
7cca0d81 |
1299 | int cipherblk, maclen, padding, i; |
1300 | static unsigned long outgoing_sequence = 0; |
1301 | |
00db133f |
1302 | log_packet(PKT_OUTGOING, pktout.data[5], ssh2_pkt_type(pktout.data[5]), |
1303 | pktout.data + 6, pktout.length - 6); |
1304 | |
7cca0d81 |
1305 | /* |
4ba9b64b |
1306 | * Compress packet payload. |
1307 | */ |
4ba9b64b |
1308 | { |
1309 | unsigned char *newpayload; |
1310 | int newlen; |
32874aea |
1311 | if (cscomp && cscomp->compress(pktout.data + 5, pktout.length - 5, |
4ba9b64b |
1312 | &newpayload, &newlen)) { |
1313 | pktout.length = 5; |
1314 | ssh2_pkt_adddata(newpayload, newlen); |
dcbde236 |
1315 | sfree(newpayload); |
4ba9b64b |
1316 | } |
1317 | } |
1318 | |
1319 | /* |
7cca0d81 |
1320 | * Add padding. At least four bytes, and must also bring total |
1321 | * length (minus MAC) up to a multiple of the block size. |
1322 | */ |
32874aea |
1323 | cipherblk = cscipher ? cscipher->blksize : 8; /* block size */ |
1324 | cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */ |
7cca0d81 |
1325 | padding = 4; |
32874aea |
1326 | padding += |
1327 | (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk; |
783415f8 |
1328 | maclen = csmac ? csmac->len : 0; |
1329 | ssh2_pkt_ensure(pktout.length + padding + maclen); |
7cca0d81 |
1330 | pktout.data[4] = padding; |
1331 | for (i = 0; i < padding; i++) |
32874aea |
1332 | pktout.data[pktout.length + i] = random_byte(); |
7cca0d81 |
1333 | PUT_32BIT(pktout.data, pktout.length + padding - 4); |
1334 | if (csmac) |
32874aea |
1335 | csmac->generate(pktout.data, pktout.length + padding, |
1336 | outgoing_sequence); |
1337 | outgoing_sequence++; /* whether or not we MACed */ |
7cca0d81 |
1338 | |
7cca0d81 |
1339 | if (cscipher) |
32874aea |
1340 | cscipher->encrypt(pktout.data, pktout.length + padding); |
7cca0d81 |
1341 | |
b185170a |
1342 | /* Ready-to-send packet starts at pktout.data. We return length. */ |
1343 | return pktout.length + padding + maclen; |
1344 | } |
1345 | |
1346 | /* |
1347 | * Construct and send an SSH2 packet immediately. |
1348 | */ |
32874aea |
1349 | static void ssh2_pkt_send(void) |
1350 | { |
5471d09a |
1351 | int len; |
1352 | int backlog; |
1353 | len = ssh2_pkt_construct(); |
1354 | backlog = sk_write(s, pktout.data, len); |
1355 | if (backlog > SSH_MAX_BACKLOG) |
1356 | ssh_throttle_all(1, backlog); |
b185170a |
1357 | } |
1358 | |
1359 | /* |
1360 | * Construct an SSH2 packet and add it to a deferred data block. |
1361 | * Useful for sending multiple packets in a single sk_write() call, |
1362 | * to prevent a traffic-analysing listener from being able to work |
1363 | * out the length of any particular packet (such as the password |
1364 | * packet). |
1365 | * |
1366 | * Note that because SSH2 sequence-numbers its packets, this can |
1367 | * NOT be used as an m4-style `defer' allowing packets to be |
1368 | * constructed in one order and sent in another. |
1369 | */ |
32874aea |
1370 | static void ssh2_pkt_defer(void) |
1371 | { |
b185170a |
1372 | int len = ssh2_pkt_construct(); |
1373 | if (deferred_len + len > deferred_size) { |
32874aea |
1374 | deferred_size = deferred_len + len + 128; |
1375 | deferred_send_data = srealloc(deferred_send_data, deferred_size); |
b185170a |
1376 | } |
32874aea |
1377 | memcpy(deferred_send_data + deferred_len, pktout.data, len); |
b185170a |
1378 | deferred_len += len; |
1379 | } |
1380 | |
1381 | /* |
1382 | * Send the whole deferred data block constructed by |
39065bed |
1383 | * ssh2_pkt_defer() or SSH1's defer_packet(). |
b185170a |
1384 | */ |
32874aea |
1385 | static void ssh_pkt_defersend(void) |
1386 | { |
5471d09a |
1387 | int backlog; |
1388 | backlog = sk_write(s, deferred_send_data, deferred_len); |
b185170a |
1389 | deferred_len = deferred_size = 0; |
1390 | sfree(deferred_send_data); |
1391 | deferred_send_data = NULL; |
5471d09a |
1392 | if (backlog > SSH_MAX_BACKLOG) |
1393 | ssh_throttle_all(1, backlog); |
7cca0d81 |
1394 | } |
1395 | |
1396 | #if 0 |
32874aea |
1397 | void bndebug(char *string, Bignum b) |
1398 | { |
7cca0d81 |
1399 | unsigned char *p; |
1400 | int i, len; |
1401 | p = ssh2_mpint_fmt(b, &len); |
1402 | debug(("%s", string)); |
1403 | for (i = 0; i < len; i++) |
32874aea |
1404 | debug((" %02x", p[i])); |
765c4200 |
1405 | debug(("\n")); |
dcbde236 |
1406 | sfree(p); |
7cca0d81 |
1407 | } |
1408 | #endif |
1409 | |
32874aea |
1410 | static void sha_mpint(SHA_State * s, Bignum b) |
1411 | { |
7cca0d81 |
1412 | unsigned char *p; |
1413 | int len; |
1414 | p = ssh2_mpint_fmt(b, &len); |
1415 | sha_string(s, p, len); |
dcbde236 |
1416 | sfree(p); |
7cca0d81 |
1417 | } |
1418 | |
1419 | /* |
1420 | * SSH2 packet decode functions. |
1421 | */ |
32874aea |
1422 | static unsigned long ssh2_pkt_getuint32(void) |
1423 | { |
7cca0d81 |
1424 | unsigned long value; |
1425 | if (pktin.length - pktin.savedpos < 4) |
32874aea |
1426 | return 0; /* arrgh, no way to decline (FIXME?) */ |
1427 | value = GET_32BIT(pktin.data + pktin.savedpos); |
7cca0d81 |
1428 | pktin.savedpos += 4; |
1429 | return value; |
1430 | } |
32874aea |
1431 | static int ssh2_pkt_getbool(void) |
1432 | { |
65a22376 |
1433 | unsigned long value; |
1434 | if (pktin.length - pktin.savedpos < 1) |
32874aea |
1435 | return 0; /* arrgh, no way to decline (FIXME?) */ |
65a22376 |
1436 | value = pktin.data[pktin.savedpos] != 0; |
1437 | pktin.savedpos++; |
1438 | return value; |
1439 | } |
32874aea |
1440 | static void ssh2_pkt_getstring(char **p, int *length) |
1441 | { |
7cca0d81 |
1442 | *p = NULL; |
1443 | if (pktin.length - pktin.savedpos < 4) |
32874aea |
1444 | return; |
1445 | *length = GET_32BIT(pktin.data + pktin.savedpos); |
7cca0d81 |
1446 | pktin.savedpos += 4; |
1447 | if (pktin.length - pktin.savedpos < *length) |
32874aea |
1448 | return; |
1449 | *p = pktin.data + pktin.savedpos; |
7cca0d81 |
1450 | pktin.savedpos += *length; |
1451 | } |
32874aea |
1452 | static Bignum ssh2_pkt_getmp(void) |
1453 | { |
7cca0d81 |
1454 | char *p; |
3709bfe9 |
1455 | int length; |
7cca0d81 |
1456 | Bignum b; |
1457 | |
1458 | ssh2_pkt_getstring(&p, &length); |
1459 | if (!p) |
32874aea |
1460 | return NULL; |
8d5de777 |
1461 | if (p[0] & 0x80) { |
32874aea |
1462 | bombout(("internal error: Can't handle negative mpints")); |
1463 | return NULL; |
8d5de777 |
1464 | } |
3709bfe9 |
1465 | b = bignum_from_bytes(p, length); |
7cca0d81 |
1466 | return b; |
1467 | } |
1468 | |
7d503c31 |
1469 | /* |
1470 | * Examine the remote side's version string and compare it against |
1471 | * a list of known buggy implementations. |
1472 | */ |
32874aea |
1473 | static void ssh_detect_bugs(char *vstring) |
1474 | { |
1475 | char *imp; /* pointer to implementation part */ |
7d503c31 |
1476 | imp = vstring; |
1477 | imp += strcspn(imp, "-"); |
bd358db1 |
1478 | if (*imp) imp++; |
7d503c31 |
1479 | imp += strcspn(imp, "-"); |
bd358db1 |
1480 | if (*imp) imp++; |
7d503c31 |
1481 | |
1482 | ssh_remote_bugs = 0; |
1483 | |
1484 | if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") || |
32874aea |
1485 | !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") || |
bd358db1 |
1486 | !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")) { |
32874aea |
1487 | /* |
1488 | * These versions don't support SSH1_MSG_IGNORE, so we have |
1489 | * to use a different defence against password length |
1490 | * sniffing. |
1491 | */ |
1492 | ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE; |
1493 | logevent("We believe remote version has SSH1 ignore bug"); |
7d503c31 |
1494 | } |
1495 | |
bd358db1 |
1496 | if (!strcmp(imp, "Cisco-1.25")) { |
1497 | /* |
1498 | * These versions need a plain password sent; they can't |
1499 | * handle having a null and a random length of data after |
1500 | * the password. |
1501 | */ |
1502 | ssh_remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD; |
1503 | logevent("We believe remote version needs a plain SSH1 password"); |
1504 | } |
1505 | |
7d503c31 |
1506 | if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) || |
32874aea |
1507 | !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) || |
1508 | !strncmp(imp, "2.1 ", 4)) { |
1509 | /* |
1510 | * These versions have the HMAC bug. |
1511 | */ |
1512 | ssh_remote_bugs |= BUG_SSH2_HMAC; |
1513 | logevent("We believe remote version has SSH2 HMAC bug"); |
7d503c31 |
1514 | } |
1515 | } |
1516 | |
32874aea |
1517 | static int do_ssh_init(unsigned char c) |
1518 | { |
2d466ffd |
1519 | static int vslen; |
8df7a775 |
1520 | static char version[10]; |
50526e47 |
1521 | static char *vstring; |
1522 | static int vstrsize; |
1523 | static char *vlog; |
8df7a775 |
1524 | static int i; |
374330e2 |
1525 | |
8df7a775 |
1526 | crBegin; |
1527 | |
1528 | /* Search for the string "SSH-" in the input. */ |
374330e2 |
1529 | i = 0; |
8df7a775 |
1530 | while (1) { |
1531 | static const int transS[] = { 1, 2, 2, 1 }; |
1532 | static const int transH[] = { 0, 0, 3, 0 }; |
1533 | static const int transminus[] = { 0, 0, 0, -1 }; |
32874aea |
1534 | if (c == 'S') |
1535 | i = transS[i]; |
1536 | else if (c == 'H') |
1537 | i = transH[i]; |
1538 | else if (c == '-') |
1539 | i = transminus[i]; |
1540 | else |
1541 | i = 0; |
8df7a775 |
1542 | if (i < 0) |
1543 | break; |
1544 | crReturn(1); /* get another character */ |
374330e2 |
1545 | } |
8df7a775 |
1546 | |
50526e47 |
1547 | vstrsize = 16; |
bd358db1 |
1548 | vstring = smalloc(vstrsize); |
c5e9c988 |
1549 | strcpy(vstring, "SSH-"); |
50526e47 |
1550 | vslen = 4; |
374330e2 |
1551 | i = 0; |
1552 | while (1) { |
8df7a775 |
1553 | crReturn(1); /* get another char */ |
32874aea |
1554 | if (vslen >= vstrsize - 1) { |
1555 | vstrsize += 16; |
1556 | vstring = srealloc(vstring, vstrsize); |
1557 | } |
1558 | vstring[vslen++] = c; |
374330e2 |
1559 | if (i >= 0) { |
1560 | if (c == '-') { |
1561 | version[i] = '\0'; |
1562 | i = -1; |
32874aea |
1563 | } else if (i < sizeof(version) - 1) |
374330e2 |
1564 | version[i++] = c; |
32874aea |
1565 | } else if (c == '\n') |
374330e2 |
1566 | break; |
1567 | } |
1568 | |
db7d555c |
1569 | ssh_agentfwd_enabled = FALSE; |
960e736a |
1570 | rdpkt2_state.incoming_sequence = 0; |
1571 | |
50526e47 |
1572 | vstring[vslen] = 0; |
9275ca8a |
1573 | vlog = smalloc(20 + vslen); |
bd358db1 |
1574 | vstring[strcspn (vstring, "\r\n")] = '\0'; /* remove end-of-line chars */ |
c5e9c988 |
1575 | sprintf(vlog, "Server version: %s", vstring); |
c5e9c988 |
1576 | logevent(vlog); |
bd358db1 |
1577 | ssh_detect_bugs(vstring); |
9275ca8a |
1578 | sfree(vlog); |
c5e9c988 |
1579 | |
adf799dd |
1580 | /* |
1581 | * Server version "1.99" means we can choose whether we use v1 |
1582 | * or v2 protocol. Choice is based on cfg.sshprot. |
1583 | */ |
1584 | if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) { |
32874aea |
1585 | /* |
1586 | * This is a v2 server. Begin v2 protocol. |
1587 | */ |
1588 | char verstring[80], vlog[100]; |
1589 | sprintf(verstring, "SSH-2.0-%s", sshver); |
1590 | SHA_Init(&exhashbase); |
1591 | /* |
1592 | * Hash our version string and their version string. |
1593 | */ |
1594 | sha_string(&exhashbase, verstring, strlen(verstring)); |
1595 | sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n")); |
1596 | sprintf(vlog, "We claim version: %s", verstring); |
1597 | logevent(vlog); |
1598 | strcat(verstring, "\n"); |
1599 | logevent("Using SSH protocol version 2"); |
1600 | sk_write(s, verstring, strlen(verstring)); |
1601 | ssh_protocol = ssh2_protocol; |
1602 | ssh_version = 2; |
1603 | s_rdpkt = ssh2_rdpkt; |
e5574168 |
1604 | } else { |
32874aea |
1605 | /* |
1606 | * This is a v1 server. Begin v1 protocol. |
1607 | */ |
1608 | char verstring[80], vlog[100]; |
1609 | sprintf(verstring, "SSH-%s-%s", |
1610 | (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"), |
1611 | sshver); |
1612 | sprintf(vlog, "We claim version: %s", verstring); |
1613 | logevent(vlog); |
1614 | strcat(verstring, "\n"); |
1615 | logevent("Using SSH protocol version 1"); |
1616 | sk_write(s, verstring, strlen(verstring)); |
1617 | ssh_protocol = ssh1_protocol; |
1618 | ssh_version = 1; |
1619 | s_rdpkt = ssh1_rdpkt; |
e5574168 |
1620 | } |
3687d221 |
1621 | ssh_state = SSH_STATE_BEFORE_SIZE; |
8df7a775 |
1622 | |
50526e47 |
1623 | sfree(vstring); |
50526e47 |
1624 | |
8df7a775 |
1625 | crFinish(0); |
1626 | } |
1627 | |
1628 | static void ssh_gotdata(unsigned char *data, int datalen) |
1629 | { |
1630 | crBegin; |
1631 | |
1632 | /* |
1633 | * To begin with, feed the characters one by one to the |
1634 | * protocol initialisation / selection function do_ssh_init(). |
1635 | * When that returns 0, we're done with the initial greeting |
1636 | * exchange and can move on to packet discipline. |
1637 | */ |
1638 | while (1) { |
1639 | int ret; |
1640 | if (datalen == 0) |
1641 | crReturnV; /* more data please */ |
1642 | ret = do_ssh_init(*data); |
32874aea |
1643 | data++; |
1644 | datalen--; |
8df7a775 |
1645 | if (ret == 0) |
1646 | break; |
1647 | } |
1648 | |
1649 | /* |
1650 | * We emerge from that loop when the initial negotiation is |
1651 | * over and we have selected an s_rdpkt function. Now pass |
1652 | * everything to s_rdpkt, and then pass the resulting packets |
1653 | * to the proper protocol handler. |
1654 | */ |
1655 | if (datalen == 0) |
1656 | crReturnV; |
1657 | while (1) { |
1658 | while (datalen > 0) { |
32874aea |
1659 | if (s_rdpkt(&data, &datalen) == 0) { |
e14d0f19 |
1660 | if (ssh_state == SSH_STATE_CLOSED) { |
1661 | return; |
1662 | } |
8df7a775 |
1663 | ssh_protocol(NULL, 0, 1); |
1664 | if (ssh_state == SSH_STATE_CLOSED) { |
1665 | return; |
1666 | } |
1667 | } |
1668 | } |
1669 | crReturnV; |
1670 | } |
1671 | crFinishV; |
1672 | } |
1673 | |
32874aea |
1674 | static int ssh_closing(Plug plug, char *error_msg, int error_code, |
1675 | int calling_back) |
1676 | { |
7e78000d |
1677 | ssh_state = SSH_STATE_CLOSED; |
f3ab576e |
1678 | if (s) { |
1679 | sk_close(s); |
1680 | s = NULL; |
1681 | } |
7e78000d |
1682 | if (error_msg) { |
32874aea |
1683 | /* A socket error has occurred. */ |
1684 | connection_fatal(error_msg); |
7e78000d |
1685 | } else { |
1686 | /* Otherwise, the remote side closed the connection normally. */ |
8df7a775 |
1687 | } |
7e78000d |
1688 | return 0; |
1689 | } |
1690 | |
32874aea |
1691 | static int ssh_receive(Plug plug, int urgent, char *data, int len) |
1692 | { |
1693 | ssh_gotdata(data, len); |
3257deae |
1694 | if (ssh_state == SSH_STATE_CLOSED) { |
32874aea |
1695 | if (s) { |
1696 | sk_close(s); |
1697 | s = NULL; |
1698 | } |
1699 | return 0; |
3257deae |
1700 | } |
fef97f43 |
1701 | return 1; |
374330e2 |
1702 | } |
1703 | |
5471d09a |
1704 | static void ssh_sent(Plug plug, int bufsize) |
1705 | { |
1706 | /* |
1707 | * If the send backlog on the SSH socket itself clears, we |
1708 | * should unthrottle the whole world if it was throttled. |
1709 | */ |
1710 | if (bufsize < SSH_MAX_BACKLOG) |
1711 | ssh_throttle_all(0, bufsize); |
1712 | } |
1713 | |
fb09bf1c |
1714 | /* |
8df7a775 |
1715 | * Connect to specified host and port. |
1716 | * Returns an error message, or NULL on success. |
6e1ebb76 |
1717 | * Also places the canonical host name into `realhost'. It must be |
1718 | * freed by the caller. |
8df7a775 |
1719 | */ |
2184a5d9 |
1720 | static char *connect_to_host(char *host, int port, char **realhost, int nodelay) |
8df7a775 |
1721 | { |
7e78000d |
1722 | static struct plug_function_table fn_table = { |
1723 | ssh_closing, |
5471d09a |
1724 | ssh_receive, |
1725 | ssh_sent, |
1726 | NULL |
7e78000d |
1727 | }, *fn_table_ptr = &fn_table; |
1728 | |
8df7a775 |
1729 | SockAddr addr; |
1730 | char *err; |
1731 | #ifdef FWHACK |
1732 | char *FWhost; |
1733 | int FWport; |
1734 | #endif |
1735 | |
32874aea |
1736 | savedhost = smalloc(1 + strlen(host)); |
8df7a775 |
1737 | if (!savedhost) |
1738 | fatalbox("Out of memory"); |
1739 | strcpy(savedhost, host); |
1740 | |
1741 | if (port < 0) |
1742 | port = 22; /* default ssh port */ |
1743 | savedport = port; |
1744 | |
1745 | #ifdef FWHACK |
1746 | FWhost = host; |
1747 | FWport = port; |
1748 | host = FWSTR; |
1749 | port = 23; |
1750 | #endif |
1751 | |
1752 | /* |
1753 | * Try to find host. |
1754 | */ |
3ad9d396 |
1755 | { |
1756 | char buf[200]; |
1757 | sprintf(buf, "Looking up host \"%.170s\"", host); |
1758 | logevent(buf); |
1759 | } |
8df7a775 |
1760 | addr = sk_namelookup(host, realhost); |
32874aea |
1761 | if ((err = sk_addr_error(addr))) |
8df7a775 |
1762 | return err; |
1763 | |
1764 | #ifdef FWHACK |
6e1ebb76 |
1765 | *realhost = strdup(FWhost); |
8df7a775 |
1766 | #endif |
1767 | |
1768 | /* |
1769 | * Open socket. |
1770 | */ |
3ad9d396 |
1771 | { |
1772 | char buf[200], addrbuf[100]; |
1773 | sk_getaddr(addr, addrbuf, 100); |
1774 | sprintf(buf, "Connecting to %.100s port %d", addrbuf, port); |
1775 | logevent(buf); |
1776 | } |
2184a5d9 |
1777 | s = sk_new(addr, port, 0, 1, nodelay, &fn_table_ptr); |
32874aea |
1778 | if ((err = sk_socket_error(s))) |
8df7a775 |
1779 | return err; |
1780 | |
1781 | #ifdef FWHACK |
1782 | sk_write(s, "connect ", 8); |
1783 | sk_write(s, FWhost, strlen(FWhost)); |
1784 | { |
1785 | char buf[20]; |
1786 | sprintf(buf, " %d\n", FWport); |
1787 | sk_write(s, buf, strlen(buf)); |
1788 | } |
1789 | #endif |
1790 | |
1791 | return NULL; |
1792 | } |
1793 | |
1794 | /* |
5471d09a |
1795 | * Throttle or unthrottle the SSH connection. |
1796 | */ |
1797 | static void ssh1_throttle(int adjust) |
1798 | { |
1799 | int old_count = ssh1_throttle_count; |
1800 | ssh1_throttle_count += adjust; |
1801 | assert(ssh1_throttle_count >= 0); |
1802 | if (ssh1_throttle_count && !old_count) { |
1803 | sk_set_frozen(s, 1); |
1804 | } else if (!ssh1_throttle_count && old_count) { |
1805 | sk_set_frozen(s, 0); |
1806 | } |
1807 | } |
1808 | |
1809 | /* |
1810 | * Throttle or unthrottle _all_ local data streams (for when sends |
1811 | * on the SSH connection itself back up). |
1812 | */ |
1813 | static void ssh_throttle_all(int enable, int bufsize) |
1814 | { |
1815 | int i; |
1816 | struct ssh_channel *c; |
1817 | |
1818 | if (enable == ssh_throttled_all) |
1819 | return; |
1820 | ssh_throttled_all = enable; |
1821 | ssh_overall_bufsize = bufsize; |
1822 | if (!ssh_channels) |
1823 | return; |
1824 | for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) { |
1825 | switch (c->type) { |
1826 | case CHAN_MAINSESSION: |
1827 | /* |
1828 | * This is treated separately, outside the switch. |
1829 | */ |
1830 | break; |
1831 | case CHAN_X11: |
1832 | x11_override_throttle(c->u.x11.s, enable); |
1833 | break; |
1834 | case CHAN_AGENT: |
1835 | /* Agent channels require no buffer management. */ |
1836 | break; |
1837 | case CHAN_SOCKDATA: |
1838 | pfd_override_throttle(c->u.x11.s, enable); |
1839 | break; |
1840 | } |
1841 | } |
1842 | } |
1843 | |
1844 | /* |
fb09bf1c |
1845 | * Handle the key exchange and user authentication phases. |
1846 | */ |
e5574168 |
1847 | static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) |
fb09bf1c |
1848 | { |
2d466ffd |
1849 | int i, j; |
1850 | static int len; |
1851 | static unsigned char *rsabuf, *keystr1, *keystr2; |
374330e2 |
1852 | unsigned char cookie[8]; |
1853 | struct RSAKey servkey, hostkey; |
1854 | struct MD5Context md5c; |
ccbfb941 |
1855 | static unsigned long supported_ciphers_mask, supported_auths_mask; |
7cca0d81 |
1856 | static int tried_publickey; |
614a20a0 |
1857 | static int tis_auth_refused, ccard_auth_refused; |
7cca0d81 |
1858 | static unsigned char session_id[16]; |
2d466ffd |
1859 | static int cipher_type; |
b585ec46 |
1860 | static char username[100]; |
374330e2 |
1861 | |
374330e2 |
1862 | crBegin; |
1863 | |
32874aea |
1864 | if (!ispkt) |
1865 | crWaitUntil(ispkt); |
374330e2 |
1866 | |
8d5de777 |
1867 | if (pktin.type != SSH1_SMSG_PUBLIC_KEY) { |
1868 | bombout(("Public key packet not received")); |
32874aea |
1869 | crReturn(0); |
8d5de777 |
1870 | } |
374330e2 |
1871 | |
c5e9c988 |
1872 | logevent("Received public keys"); |
374330e2 |
1873 | |
c5e9c988 |
1874 | memcpy(cookie, pktin.body, 8); |
374330e2 |
1875 | |
32874aea |
1876 | i = makekey(pktin.body + 8, &servkey, &keystr1, 0); |
1877 | j = makekey(pktin.body + 8 + i, &hostkey, &keystr2, 0); |
374330e2 |
1878 | |
c5e9c988 |
1879 | /* |
1c2a93c4 |
1880 | * Log the host key fingerprint. |
c5e9c988 |
1881 | */ |
c5e9c988 |
1882 | { |
1883 | char logmsg[80]; |
1c2a93c4 |
1884 | logevent("Host key fingerprint is:"); |
c5e9c988 |
1885 | strcpy(logmsg, " "); |
32874aea |
1886 | hostkey.comment = NULL; |
1887 | rsa_fingerprint(logmsg + strlen(logmsg), |
1888 | sizeof(logmsg) - strlen(logmsg), &hostkey); |
c5e9c988 |
1889 | logevent(logmsg); |
1890 | } |
1891 | |
32874aea |
1892 | ssh1_remote_protoflags = GET_32BIT(pktin.body + 8 + i + j); |
1893 | supported_ciphers_mask = GET_32BIT(pktin.body + 12 + i + j); |
1894 | supported_auths_mask = GET_32BIT(pktin.body + 16 + i + j); |
bea1ef5f |
1895 | |
32874aea |
1896 | ssh1_local_protoflags = |
1897 | ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED; |
b96dc54c |
1898 | ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER; |
1899 | |
c5e9c988 |
1900 | MD5Init(&md5c); |
374330e2 |
1901 | MD5Update(&md5c, keystr2, hostkey.bytes); |
1902 | MD5Update(&md5c, keystr1, servkey.bytes); |
1903 | MD5Update(&md5c, pktin.body, 8); |
374330e2 |
1904 | MD5Final(session_id, &md5c); |
1905 | |
32874aea |
1906 | for (i = 0; i < 32; i++) |
374330e2 |
1907 | session_key[i] = random_byte(); |
1908 | |
1909 | len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes); |
1910 | |
dcbde236 |
1911 | rsabuf = smalloc(len); |
374330e2 |
1912 | if (!rsabuf) |
1913 | fatalbox("Out of memory"); |
1914 | |
89ee5268 |
1915 | /* |
1916 | * Verify the host key. |
1917 | */ |
1918 | { |
32874aea |
1919 | /* |
1920 | * First format the key into a string. |
1921 | */ |
1922 | int len = rsastr_len(&hostkey); |
1923 | char fingerprint[100]; |
1924 | char *keystr = smalloc(len); |
1925 | if (!keystr) |
1926 | fatalbox("Out of memory"); |
1927 | rsastr_fmt(keystr, &hostkey); |
1928 | rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey); |
1929 | verify_ssh_host_key(savedhost, savedport, "rsa", keystr, |
1930 | fingerprint); |
1931 | sfree(keystr); |
1932 | } |
1933 | |
1934 | for (i = 0; i < 32; i++) { |
374330e2 |
1935 | rsabuf[i] = session_key[i]; |
1936 | if (i < 16) |
1937 | rsabuf[i] ^= session_id[i]; |
1938 | } |
1939 | |
1940 | if (hostkey.bytes > servkey.bytes) { |
1941 | rsaencrypt(rsabuf, 32, &servkey); |
1942 | rsaencrypt(rsabuf, servkey.bytes, &hostkey); |
1943 | } else { |
1944 | rsaencrypt(rsabuf, 32, &hostkey); |
1945 | rsaencrypt(rsabuf, hostkey.bytes, &servkey); |
1946 | } |
1947 | |
c5e9c988 |
1948 | logevent("Encrypted session key"); |
1949 | |
ca20bfcf |
1950 | { |
1951 | int cipher_chosen = 0, warn = 0; |
1952 | char *cipher_string = NULL; |
1953 | for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) { |
1954 | int next_cipher = cfg.ssh_cipherlist[i]; |
1955 | if (next_cipher == CIPHER_WARN) { |
1956 | /* If/when we choose a cipher, warn about it */ |
1957 | warn = 1; |
1958 | } else if (next_cipher == CIPHER_AES) { |
1959 | /* XXX Probably don't need to mention this. */ |
1960 | logevent("AES not supported in SSH1, skipping"); |
1961 | } else { |
1962 | switch (next_cipher) { |
1963 | case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES; |
1964 | cipher_string = "3DES"; break; |
1965 | case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH; |
1966 | cipher_string = "Blowfish"; break; |
1967 | case CIPHER_DES: cipher_type = SSH_CIPHER_DES; |
1968 | cipher_string = "single-DES"; break; |
1969 | } |
1970 | if (supported_ciphers_mask & (1 << cipher_type)) |
1971 | cipher_chosen = 1; |
1972 | } |
1973 | } |
1974 | if (!cipher_chosen) { |
1975 | if ((supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0) |
1976 | bombout(("Server violates SSH 1 protocol by not " |
1977 | "supporting 3DES encryption")); |
1978 | else |
1979 | /* shouldn't happen */ |
1980 | bombout(("No supported ciphers found")); |
a99a05c0 |
1981 | crReturn(0); |
1982 | } |
ca20bfcf |
1983 | |
1984 | /* Warn about chosen cipher if necessary. */ |
1985 | if (warn) |
1986 | askcipher(cipher_string, 0); |
bea1ef5f |
1987 | } |
ca20bfcf |
1988 | |
c5e9c988 |
1989 | switch (cipher_type) { |
32874aea |
1990 | case SSH_CIPHER_3DES: |
1991 | logevent("Using 3DES encryption"); |
1992 | break; |
1993 | case SSH_CIPHER_DES: |
1994 | logevent("Using single-DES encryption"); |
1995 | break; |
1996 | case SSH_CIPHER_BLOWFISH: |
1997 | logevent("Using Blowfish encryption"); |
1998 | break; |
c5e9c988 |
1999 | } |
bea1ef5f |
2000 | |
e5574168 |
2001 | send_packet(SSH1_CMSG_SESSION_KEY, |
32874aea |
2002 | PKT_CHAR, cipher_type, |
2003 | PKT_DATA, cookie, 8, |
2004 | PKT_CHAR, (len * 8) >> 8, PKT_CHAR, (len * 8) & 0xFF, |
2005 | PKT_DATA, rsabuf, len, |
2006 | PKT_INT, ssh1_local_protoflags, PKT_END); |
fb09bf1c |
2007 | |
c5e9c988 |
2008 | logevent("Trying to enable encryption..."); |
374330e2 |
2009 | |
dcbde236 |
2010 | sfree(rsabuf); |
374330e2 |
2011 | |
5e8358ad |
2012 | cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 : |
32874aea |
2013 | cipher_type == SSH_CIPHER_DES ? &ssh_des : &ssh_3des; |
374330e2 |
2014 | cipher->sesskey(session_key); |
2015 | |
fb09bf1c |
2016 | crWaitUntil(ispkt); |
374330e2 |
2017 | |
8d5de777 |
2018 | if (pktin.type != SSH1_SMSG_SUCCESS) { |
2019 | bombout(("Encryption not successfully enabled")); |
32874aea |
2020 | crReturn(0); |
8d5de777 |
2021 | } |
374330e2 |
2022 | |
c5e9c988 |
2023 | logevent("Successfully started encryption"); |
2024 | |
374330e2 |
2025 | fflush(stdout); |
2026 | { |
374330e2 |
2027 | static int pos = 0; |
2028 | static char c; |
67779be7 |
2029 | if ((flags & FLAG_INTERACTIVE) && !*cfg.username) { |
32874aea |
2030 | if (ssh_get_line) { |
2031 | if (!ssh_get_line("login as: ", |
2032 | username, sizeof(username), FALSE)) { |
2033 | /* |
2034 | * get_line failed to get a username. |
2035 | * Terminate. |
2036 | */ |
2037 | logevent("No username provided. Abandoning session."); |
2038 | ssh_state = SSH_STATE_CLOSED; |
2039 | crReturn(1); |
2040 | } |
2041 | } else { |
2042 | c_write_str("login as: "); |
2043 | ssh_send_ok = 1; |
2044 | while (pos >= 0) { |
2045 | crWaitUntil(!ispkt); |
2046 | while (inlen--) |
2047 | switch (c = *in++) { |
2048 | case 10: |
2049 | case 13: |
2050 | username[pos] = 0; |
2051 | pos = -1; |
2052 | break; |
2053 | case 8: |
2054 | case 127: |
2055 | if (pos > 0) { |
2056 | c_write_str("\b \b"); |
2057 | pos--; |
2058 | } |
2059 | break; |
2060 | case 21: |
2061 | case 27: |
2062 | while (pos > 0) { |
2063 | c_write_str("\b \b"); |
2064 | pos--; |
2065 | } |
2066 | break; |
2067 | case 3: |
2068 | case 4: |
2069 | random_save_seed(); |
2070 | exit(0); |
2071 | break; |
2072 | default: |
2073 | if (((c >= ' ' && c <= '~') || |
51b2fb65 |
2074 | ((unsigned char) c >= 160)) |
2075 | && pos < sizeof(username)-1) { |
32874aea |
2076 | username[pos++] = c; |
2077 | c_write(&c, 1); |
2078 | } |
2079 | break; |
2080 | } |
2081 | } |
2082 | c_write_str("\r\n"); |
2083 | username[strcspn(username, "\n\r")] = '\0'; |
2084 | } |
2085 | } else { |
374330e2 |
2086 | strncpy(username, cfg.username, 99); |
2087 | username[99] = '\0'; |
374330e2 |
2088 | } |
fb09bf1c |
2089 | |
e5574168 |
2090 | send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END); |
c5e9c988 |
2091 | { |
32874aea |
2092 | char userlog[22 + sizeof(username)]; |
c5e9c988 |
2093 | sprintf(userlog, "Sent username \"%s\"", username); |
2094 | logevent(userlog); |
32874aea |
2095 | if (flags & FLAG_INTERACTIVE && |
2096 | (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) { |
3c8e959b |
2097 | strcat(userlog, "\r\n"); |
32874aea |
2098 | c_write_str(userlog); |
3c8e959b |
2099 | } |
c5e9c988 |
2100 | } |
374330e2 |
2101 | } |
2102 | |
fb09bf1c |
2103 | crWaitUntil(ispkt); |
374330e2 |
2104 | |
7cca0d81 |
2105 | tried_publickey = 0; |
614a20a0 |
2106 | tis_auth_refused = ccard_auth_refused = 0; |
7cca0d81 |
2107 | |
e5574168 |
2108 | while (pktin.type == SSH1_SMSG_FAILURE) { |
374330e2 |
2109 | static char password[100]; |
a52f067e |
2110 | static char prompt[200]; |
374330e2 |
2111 | static int pos; |
2112 | static char c; |
32874aea |
2113 | static int pwpkt_type; |
32874aea |
2114 | pwpkt_type = SSH1_CMSG_AUTH_PASSWORD; |
614a20a0 |
2115 | |
32874aea |
2116 | if (agent_exists()) { |
2117 | /* |
2118 | * Attempt RSA authentication using Pageant. |
2119 | */ |
2120 | static unsigned char request[5], *response, *p; |
2121 | static int responselen; |
2122 | static int i, nkeys; |
2123 | static int authed = FALSE; |
2124 | void *r; |
2125 | |
2126 | logevent("Pageant is running. Requesting keys."); |
2127 | |
2128 | /* Request the keys held by the agent. */ |
2129 | PUT_32BIT(request, 1); |
2130 | request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES; |
2131 | agent_query(request, 5, &r, &responselen); |
2132 | response = (unsigned char *) r; |
2133 | if (response && responselen >= 5 && |
2134 | response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) { |
2135 | p = response + 5; |
2136 | nkeys = GET_32BIT(p); |
2137 | p += 4; |
2138 | { |
2139 | char buf[64]; |
2140 | sprintf(buf, "Pageant has %d SSH1 keys", nkeys); |
2141 | logevent(buf); |
2142 | } |
2143 | for (i = 0; i < nkeys; i++) { |
2144 | static struct RSAKey key; |
2145 | static Bignum challenge; |
2146 | static char *commentp; |
2147 | static int commentlen; |
2148 | |
2149 | { |
2150 | char buf[64]; |
2151 | sprintf(buf, "Trying Pageant key #%d", i); |
2152 | logevent(buf); |
2153 | } |
2154 | p += 4; |
2155 | p += ssh1_read_bignum(p, &key.exponent); |
2156 | p += ssh1_read_bignum(p, &key.modulus); |
2157 | commentlen = GET_32BIT(p); |
2158 | p += 4; |
2159 | commentp = p; |
2160 | p += commentlen; |
2161 | send_packet(SSH1_CMSG_AUTH_RSA, |
2162 | PKT_BIGNUM, key.modulus, PKT_END); |
2163 | crWaitUntil(ispkt); |
2164 | if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { |
2165 | logevent("Key refused"); |
2166 | continue; |
2167 | } |
2168 | logevent("Received RSA challenge"); |
2169 | ssh1_read_bignum(pktin.body, &challenge); |
2170 | { |
2171 | char *agentreq, *q, *ret; |
2d466ffd |
2172 | void *vret; |
32874aea |
2173 | int len, retlen; |
2174 | len = 1 + 4; /* message type, bit count */ |
2175 | len += ssh1_bignum_length(key.exponent); |
2176 | len += ssh1_bignum_length(key.modulus); |
2177 | len += ssh1_bignum_length(challenge); |
2178 | len += 16; /* session id */ |
2179 | len += 4; /* response format */ |
2180 | agentreq = smalloc(4 + len); |
2181 | PUT_32BIT(agentreq, len); |
2182 | q = agentreq + 4; |
2183 | *q++ = SSH1_AGENTC_RSA_CHALLENGE; |
2184 | PUT_32BIT(q, bignum_bitcount(key.modulus)); |
2185 | q += 4; |
2186 | q += ssh1_write_bignum(q, key.exponent); |
2187 | q += ssh1_write_bignum(q, key.modulus); |
2188 | q += ssh1_write_bignum(q, challenge); |
2189 | memcpy(q, session_id, 16); |
2190 | q += 16; |
2191 | PUT_32BIT(q, 1); /* response format */ |
2d466ffd |
2192 | agent_query(agentreq, len + 4, &vret, &retlen); |
2193 | ret = vret; |
32874aea |
2194 | sfree(agentreq); |
2195 | if (ret) { |
2196 | if (ret[4] == SSH1_AGENT_RSA_RESPONSE) { |
2197 | logevent("Sending Pageant's response"); |
2198 | send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE, |
2199 | PKT_DATA, ret + 5, 16, |
2200 | PKT_END); |
2201 | sfree(ret); |
2202 | crWaitUntil(ispkt); |
2203 | if (pktin.type == SSH1_SMSG_SUCCESS) { |
2204 | logevent |
2205 | ("Pageant's response accepted"); |
2206 | if (flags & FLAG_VERBOSE) { |
2207 | c_write_str |
2208 | ("Authenticated using RSA key \""); |
2209 | c_write(commentp, commentlen); |
2210 | c_write_str("\" from agent\r\n"); |
2211 | } |
2212 | authed = TRUE; |
2213 | } else |
2214 | logevent |
2215 | ("Pageant's response not accepted"); |
2216 | } else { |
2217 | logevent |
2218 | ("Pageant failed to answer challenge"); |
2219 | sfree(ret); |
2220 | } |
2221 | } else { |
2222 | logevent("No reply received from Pageant"); |
2223 | } |
2224 | } |
2225 | freebn(key.exponent); |
2226 | freebn(key.modulus); |
2227 | freebn(challenge); |
2228 | if (authed) |
2229 | break; |
2230 | } |
2231 | } |
2232 | if (authed) |
2233 | break; |
2234 | } |
2235 | if (*cfg.keyfile && !tried_publickey) |
2236 | pwpkt_type = SSH1_CMSG_AUTH_RSA; |
2237 | |
614a20a0 |
2238 | if (cfg.try_tis_auth && |
2239 | (supported_auths_mask & (1 << SSH1_AUTH_TIS)) && |
2240 | !tis_auth_refused) { |
32874aea |
2241 | pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE; |
2242 | logevent("Requested TIS authentication"); |
2243 | send_packet(SSH1_CMSG_AUTH_TIS, PKT_END); |
2244 | crWaitUntil(ispkt); |
2245 | if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) { |
2246 | logevent("TIS authentication declined"); |
2247 | if (flags & FLAG_INTERACTIVE) |
2248 | c_write_str("TIS authentication refused.\r\n"); |
614a20a0 |
2249 | tis_auth_refused = 1; |
2250 | continue; |
32874aea |
2251 | } else { |
2252 | int challengelen = ((pktin.body[0] << 24) | |
2253 | (pktin.body[1] << 16) | |
2254 | (pktin.body[2] << 8) | |
2255 | (pktin.body[3])); |
2256 | logevent("Received TIS challenge"); |
2257 | if (challengelen > sizeof(prompt) - 1) |
2258 | challengelen = sizeof(prompt) - 1; /* prevent overrun */ |
2259 | memcpy(prompt, pktin.body + 4, challengelen); |
614a20a0 |
2260 | /* Prompt heuristic comes from OpenSSH */ |
2261 | strncpy(prompt + challengelen, |
2262 | memchr(prompt, '\n', challengelen) ? |
2263 | "": "\r\nResponse: ", |
2264 | (sizeof prompt) - challengelen); |
2265 | prompt[(sizeof prompt) - 1] = '\0'; |
32874aea |
2266 | } |
2267 | } |
614a20a0 |
2268 | if (cfg.try_tis_auth && |
2269 | (supported_auths_mask & (1 << SSH1_AUTH_CCARD)) && |
2270 | !ccard_auth_refused) { |
32874aea |
2271 | pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE; |
2272 | logevent("Requested CryptoCard authentication"); |
2273 | send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END); |
2274 | crWaitUntil(ispkt); |
2275 | if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) { |
2276 | logevent("CryptoCard authentication declined"); |
2277 | c_write_str("CryptoCard authentication refused.\r\n"); |
614a20a0 |
2278 | ccard_auth_refused = 1; |
2279 | continue; |
32874aea |
2280 | } else { |
2281 | int challengelen = ((pktin.body[0] << 24) | |
2282 | (pktin.body[1] << 16) | |
2283 | (pktin.body[2] << 8) | |
2284 | (pktin.body[3])); |
2285 | logevent("Received CryptoCard challenge"); |
2286 | if (challengelen > sizeof(prompt) - 1) |
2287 | challengelen = sizeof(prompt) - 1; /* prevent overrun */ |
2288 | memcpy(prompt, pktin.body + 4, challengelen); |
614a20a0 |
2289 | strncpy(prompt + challengelen, |
2290 | memchr(prompt, '\n', challengelen) ? |
2291 | "" : "\r\nResponse: ", |
32874aea |
2292 | sizeof(prompt) - challengelen); |
2293 | prompt[sizeof(prompt) - 1] = '\0'; |
2294 | } |
2295 | } |
2296 | if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) { |
2297 | sprintf(prompt, "%.90s@%.90s's password: ", |
2298 | username, savedhost); |
2299 | } |
2300 | if (pwpkt_type == SSH1_CMSG_AUTH_RSA) { |
2301 | char *comment = NULL; |
2302 | if (flags & FLAG_VERBOSE) |
2303 | c_write_str("Trying public key authentication.\r\n"); |
2304 | if (!rsakey_encrypted(cfg.keyfile, &comment)) { |
2305 | if (flags & FLAG_VERBOSE) |
2306 | c_write_str("No passphrase required.\r\n"); |
2307 | goto tryauth; |
2308 | } |
2309 | sprintf(prompt, "Passphrase for key \"%.100s\": ", comment); |
2310 | sfree(comment); |
2311 | } |
a52f067e |
2312 | |
614a20a0 |
2313 | /* |
2314 | * Show password prompt, having first obtained it via a TIS |
2315 | * or CryptoCard exchange if we're doing TIS or CryptoCard |
2316 | * authentication. |
2317 | */ |
fa17a66e |
2318 | if (ssh_get_line) { |
2319 | if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) { |
32874aea |
2320 | /* |
2321 | * get_line failed to get a password (for example |
2322 | * because one was supplied on the command line |
2323 | * which has already failed to work). Terminate. |
2324 | */ |
2bc6a386 |
2325 | send_packet(SSH1_MSG_DISCONNECT, |
2326 | PKT_STR, "No more passwords available to try", |
2327 | PKT_END); |
2328 | connection_fatal("Unable to authenticate"); |
32874aea |
2329 | ssh_state = SSH_STATE_CLOSED; |
2330 | crReturn(1); |
2331 | } |
fb09bf1c |
2332 | } else { |
614a20a0 |
2333 | /* Prompt may have come from server. We've munged it a bit, so |
2334 | * we know it to be zero-terminated at least once. */ |
2335 | c_write_untrusted(prompt, strlen(prompt)); |
32874aea |
2336 | pos = 0; |
2337 | ssh_send_ok = 1; |
2338 | while (pos >= 0) { |
2339 | crWaitUntil(!ispkt); |
2340 | while (inlen--) |
2341 | switch (c = *in++) { |
2342 | case 10: |
2343 | case 13: |
2344 | password[pos] = 0; |
2345 | pos = -1; |
2346 | break; |
2347 | case 8: |
2348 | case 127: |
2349 | if (pos > 0) |
2350 | pos--; |
2351 | break; |
2352 | case 21: |
2353 | case 27: |
2354 | pos = 0; |
2355 | break; |
2356 | case 3: |
2357 | case 4: |
2358 | random_save_seed(); |
2359 | exit(0); |
2360 | break; |
2361 | default: |
51b2fb65 |
2362 | if (pos < sizeof(password)-1) |
32874aea |
2363 | password[pos++] = c; |
2364 | break; |
2365 | } |
2366 | } |
2367 | c_write_str("\r\n"); |
2368 | } |
2369 | |
2370 | tryauth: |
7cca0d81 |
2371 | if (pwpkt_type == SSH1_CMSG_AUTH_RSA) { |
32874aea |
2372 | /* |
2373 | * Try public key authentication with the specified |
2374 | * key file. |
2375 | */ |
2376 | static struct RSAKey pubkey; |
2377 | static Bignum challenge, response; |
2378 | static int i; |
2379 | static unsigned char buffer[32]; |
2380 | |
2381 | tried_publickey = 1; |
2382 | i = loadrsakey(cfg.keyfile, &pubkey, password); |
2383 | if (i == 0) { |
7963af2f |
2384 | c_write_str("Couldn't load private key from "); |
32874aea |
2385 | c_write_str(cfg.keyfile); |
2386 | c_write_str(".\r\n"); |
2387 | continue; /* go and try password */ |
2388 | } |
2389 | if (i == -1) { |
2390 | c_write_str("Wrong passphrase.\r\n"); |
2391 | tried_publickey = 0; |
2392 | continue; /* try again */ |
2393 | } |
2394 | |
2395 | /* |
2396 | * Send a public key attempt. |
2397 | */ |
2398 | send_packet(SSH1_CMSG_AUTH_RSA, |
2399 | PKT_BIGNUM, pubkey.modulus, PKT_END); |
2400 | |
2401 | crWaitUntil(ispkt); |
2402 | if (pktin.type == SSH1_SMSG_FAILURE) { |
2403 | c_write_str("Server refused our public key.\r\n"); |
2404 | continue; /* go and try password */ |
2405 | } |
2406 | if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { |
2407 | bombout(("Bizarre response to offer of public key")); |
2408 | crReturn(0); |
2409 | } |
2410 | ssh1_read_bignum(pktin.body, &challenge); |
2411 | response = rsadecrypt(challenge, &pubkey); |
2412 | freebn(pubkey.private_exponent); /* burn the evidence */ |
2413 | |
2414 | for (i = 0; i < 32; i++) { |
2415 | buffer[i] = bignum_byte(response, 31 - i); |
2416 | } |
2417 | |
2418 | MD5Init(&md5c); |
2419 | MD5Update(&md5c, buffer, 32); |
2420 | MD5Update(&md5c, session_id, 16); |
2421 | MD5Final(buffer, &md5c); |
2422 | |
2423 | send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE, |
2424 | PKT_DATA, buffer, 16, PKT_END); |
2425 | |
2426 | crWaitUntil(ispkt); |
2427 | if (pktin.type == SSH1_SMSG_FAILURE) { |
2428 | if (flags & FLAG_VERBOSE) |
2429 | c_write_str |
2430 | ("Failed to authenticate with our public key.\r\n"); |
2431 | continue; /* go and try password */ |
2432 | } else if (pktin.type != SSH1_SMSG_SUCCESS) { |
2433 | bombout( |
2434 | ("Bizarre response to RSA authentication response")); |
2435 | crReturn(0); |
2436 | } |
2437 | |
2438 | break; /* we're through! */ |
2439 | } else { |
2440 | if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) { |
2441 | /* |
2442 | * Defence against traffic analysis: we send a |
2443 | * whole bunch of packets containing strings of |
2444 | * different lengths. One of these strings is the |
2445 | * password, in a SSH1_CMSG_AUTH_PASSWORD packet. |
2446 | * The others are all random data in |
2447 | * SSH1_MSG_IGNORE packets. This way a passive |
2448 | * listener can't tell which is the password, and |
2449 | * hence can't deduce the password length. |
2450 | * |
2451 | * Anybody with a password length greater than 16 |
2452 | * bytes is going to have enough entropy in their |
2453 | * password that a listener won't find it _that_ |
2454 | * much help to know how long it is. So what we'll |
2455 | * do is: |
2456 | * |
2457 | * - if password length < 16, we send 15 packets |
2458 | * containing string lengths 1 through 15 |
2459 | * |
2460 | * - otherwise, we let N be the nearest multiple |
2461 | * of 8 below the password length, and send 8 |
2462 | * packets containing string lengths N through |
2463 | * N+7. This won't obscure the order of |
2464 | * magnitude of the password length, but it will |
2465 | * introduce a bit of extra uncertainty. |
2466 | * |
2467 | * A few servers (the old 1.2.18 through 1.2.22) |
2468 | * can't deal with SSH1_MSG_IGNORE. For these |
2469 | * servers, we need an alternative defence. We make |
2470 | * use of the fact that the password is interpreted |
2471 | * as a C string: so we can append a NUL, then some |
2472 | * random data. |
bd358db1 |
2473 | * |
2474 | * One server (a Cisco one) can deal with neither |
2475 | * SSH1_MSG_IGNORE _nor_ a padded password string. |
2476 | * For this server we are left with no defences |
2477 | * against password length sniffing. |
32874aea |
2478 | */ |
bd358db1 |
2479 | if (!(ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) { |
b17c8428 |
2480 | /* |
2481 | * The server can deal with SSH1_MSG_IGNORE, so |
2482 | * we can use the primary defence. |
2483 | */ |
32874aea |
2484 | int bottom, top, pwlen, i; |
2485 | char *randomstr; |
2486 | |
2487 | pwlen = strlen(password); |
2488 | if (pwlen < 16) { |
2489 | bottom = 0; /* zero length passwords are OK! :-) */ |
2490 | top = 15; |
2491 | } else { |
2492 | bottom = pwlen & ~7; |
2493 | top = bottom + 7; |
2494 | } |
2495 | |
2496 | assert(pwlen >= bottom && pwlen <= top); |
2497 | |
2498 | randomstr = smalloc(top + 1); |
2499 | |
2500 | for (i = bottom; i <= top; i++) { |
2501 | if (i == pwlen) |
2502 | defer_packet(pwpkt_type, PKT_STR, password, |
2503 | PKT_END); |
2504 | else { |
2505 | for (j = 0; j < i; j++) { |
2506 | do { |
2507 | randomstr[j] = random_byte(); |
2508 | } while (randomstr[j] == '\0'); |
2509 | } |
2510 | randomstr[i] = '\0'; |
2511 | defer_packet(SSH1_MSG_IGNORE, |
2512 | PKT_STR, randomstr, PKT_END); |
2513 | } |
2514 | } |
bd358db1 |
2515 | logevent("Sending password with camouflage packets"); |
32874aea |
2516 | ssh_pkt_defersend(); |
bd358db1 |
2517 | } |
2518 | else if (!(ssh_remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) { |
b17c8428 |
2519 | /* |
2520 | * The server can't deal with SSH1_MSG_IGNORE |
2521 | * but can deal with padded passwords, so we |
2522 | * can use the secondary defence. |
2523 | */ |
bd358db1 |
2524 | char string[64]; |
2525 | char *s; |
2526 | int len; |
2527 | |
2528 | len = strlen(password); |
2529 | if (len < sizeof(string)) { |
2530 | s = string; |
2531 | strcpy(string, password); |
2532 | len++; /* cover the zero byte */ |
2533 | while (len < sizeof(string)) { |
2534 | string[len++] = (char) random_byte(); |
2535 | } |
2536 | } else { |
2537 | s = password; |
2538 | } |
2539 | logevent("Sending length-padded password"); |
2540 | send_packet(pwpkt_type, PKT_INT, len, |
2541 | PKT_DATA, s, len, PKT_END); |
2542 | } else { |
2543 | /* |
2544 | * The server has _both_ |
2545 | * BUG_CHOKES_ON_SSH1_IGNORE and |
2546 | * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is |
2547 | * therefore nothing we can do. |
2548 | */ |
2549 | int len; |
2550 | len = strlen(password); |
2551 | logevent("Sending unpadded password"); |
2552 | send_packet(pwpkt_type, PKT_INT, len, |
2553 | PKT_DATA, password, len, PKT_END); |
32874aea |
2554 | } |
2555 | } else { |
2556 | send_packet(pwpkt_type, PKT_STR, password, PKT_END); |
2557 | } |
2558 | } |
c5e9c988 |
2559 | logevent("Sent password"); |
374330e2 |
2560 | memset(password, 0, strlen(password)); |
fb09bf1c |
2561 | crWaitUntil(ispkt); |
e5574168 |
2562 | if (pktin.type == SSH1_SMSG_FAILURE) { |
32874aea |
2563 | if (flags & FLAG_VERBOSE) |
2564 | c_write_str("Access denied\r\n"); |
c5e9c988 |
2565 | logevent("Authentication refused"); |
e5574168 |
2566 | } else if (pktin.type == SSH1_MSG_DISCONNECT) { |
fb09bf1c |
2567 | logevent("Received disconnect request"); |
32874aea |
2568 | ssh_state = SSH_STATE_CLOSED; |
85ee8208 |
2569 | crReturn(1); |
e5574168 |
2570 | } else if (pktin.type != SSH1_SMSG_SUCCESS) { |
8d5de777 |
2571 | bombout(("Strange packet received, type %d", pktin.type)); |
32874aea |
2572 | crReturn(0); |
374330e2 |
2573 | } |
2574 | } |
2575 | |
c5e9c988 |
2576 | logevent("Authentication successful"); |
2577 | |
fb09bf1c |
2578 | crFinish(1); |
2579 | } |
2580 | |
32874aea |
2581 | void sshfwd_close(struct ssh_channel *c) |
2582 | { |
80e48603 |
2583 | if (c && !c->closes) { |
4ed34d25 |
2584 | /* |
2585 | * If the channel's remoteid is -1, we have sent |
2586 | * CHANNEL_OPEN for this channel, but it hasn't even been |
2587 | * acknowledged by the server. So we must set a close flag |
2588 | * on it now, and then when the server acks the channel |
2589 | * open, we can close it then. |
2590 | */ |
2591 | if (c->remoteid != -1) { |
2592 | if (ssh_version == 1) { |
2593 | send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, |
2594 | PKT_END); |
2595 | } else { |
2596 | ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); |
2597 | ssh2_pkt_adduint32(c->remoteid); |
2598 | ssh2_pkt_send(); |
2599 | } |
32874aea |
2600 | } |
2601 | c->closes = 1; |
2602 | if (c->type == CHAN_X11) { |
2603 | c->u.x11.s = NULL; |
d74d141c |
2604 | logevent("Forwarded X11 connection terminated"); |
4ed34d25 |
2605 | } else if (c->type == CHAN_SOCKDATA || |
2606 | c->type == CHAN_SOCKDATA_DORMANT) { |
d74d141c |
2607 | c->u.pfd.s = NULL; |
2608 | logevent("Forwarded port closed"); |
32874aea |
2609 | } |
2610 | } |
2611 | } |
2612 | |
5471d09a |
2613 | int sshfwd_write(struct ssh_channel *c, char *buf, int len) |
32874aea |
2614 | { |
783415f8 |
2615 | if (ssh_version == 1) { |
32874aea |
2616 | send_packet(SSH1_MSG_CHANNEL_DATA, |
2617 | PKT_INT, c->remoteid, |
2618 | PKT_INT, len, PKT_DATA, buf, len, PKT_END); |
5471d09a |
2619 | /* |
2620 | * In SSH1 we can return 0 here - implying that forwarded |
2621 | * connections are never individually throttled - because |
2622 | * the only circumstance that can cause throttling will be |
2623 | * the whole SSH connection backing up, in which case |
2624 | * _everything_ will be throttled as a whole. |
2625 | */ |
2626 | return 0; |
783415f8 |
2627 | } else { |
32874aea |
2628 | ssh2_add_channel_data(c, buf, len); |
5471d09a |
2629 | return ssh2_try_send(c); |
2630 | } |
2631 | } |
2632 | |
2633 | void sshfwd_unthrottle(struct ssh_channel *c, int bufsize) |
2634 | { |
2635 | if (ssh_version == 1) { |
2636 | if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) { |
2637 | c->v.v1.throttling = 0; |
2638 | ssh1_throttle(-1); |
2639 | } |
2640 | } else { |
2641 | ssh2_set_window(c, OUR_V2_WINSIZE - bufsize); |
783415f8 |
2642 | } |
9c964e85 |
2643 | } |
2644 | |
32874aea |
2645 | static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) |
2646 | { |
fb09bf1c |
2647 | crBegin; |
2648 | |
2649 | random_init(); |
2650 | |
e5574168 |
2651 | while (!do_ssh1_login(in, inlen, ispkt)) { |
fb09bf1c |
2652 | crReturnV; |
85ee8208 |
2653 | } |
2654 | if (ssh_state == SSH_STATE_CLOSED) |
32874aea |
2655 | crReturnV; |
fb09bf1c |
2656 | |
979310f1 |
2657 | if (cfg.agentfwd && agent_exists()) { |
32874aea |
2658 | logevent("Requesting agent forwarding"); |
2659 | send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END); |
2660 | do { |
2661 | crReturnV; |
2662 | } while (!ispkt); |
2663 | if (pktin.type != SSH1_SMSG_SUCCESS |
2664 | && pktin.type != SSH1_SMSG_FAILURE) { |
2665 | bombout(("Protocol confusion")); |
2666 | crReturnV; |
2667 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
2668 | logevent("Agent forwarding refused"); |
2669 | } else { |
2670 | logevent("Agent forwarding enabled"); |
db7d555c |
2671 | ssh_agentfwd_enabled = TRUE; |
2672 | } |
dacbd0e8 |
2673 | } |
2674 | |
9c964e85 |
2675 | if (cfg.x11_forward) { |
32874aea |
2676 | char proto[20], data[64]; |
2677 | logevent("Requesting X11 forwarding"); |
2678 | x11_invent_auth(proto, sizeof(proto), data, sizeof(data)); |
2679 | if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) { |
2680 | send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING, |
2681 | PKT_STR, proto, PKT_STR, data, |
2682 | PKT_INT, 0, PKT_END); |
2683 | } else { |
2684 | send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING, |
2685 | PKT_STR, proto, PKT_STR, data, PKT_END); |
2686 | } |
2687 | do { |
2688 | crReturnV; |
2689 | } while (!ispkt); |
2690 | if (pktin.type != SSH1_SMSG_SUCCESS |
2691 | && pktin.type != SSH1_SMSG_FAILURE) { |
2692 | bombout(("Protocol confusion")); |
2693 | crReturnV; |
2694 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
2695 | logevent("X11 forwarding refused"); |
2696 | } else { |
2697 | logevent("X11 forwarding enabled"); |
9c964e85 |
2698 | ssh_X11_fwd_enabled = TRUE; |
2699 | } |
2700 | } |
2701 | |
d74d141c |
2702 | { |
2703 | char type, *e; |
2704 | int n; |
2705 | int sport,dport; |
2706 | char sports[256], dports[256], host[256]; |
2707 | char buf[1024]; |
2708 | |
bc240b21 |
2709 | ssh_rportfwds = newtree234(ssh_rportcmp_ssh1); |
d74d141c |
2710 | /* Add port forwardings. */ |
2711 | e = cfg.portfwd; |
2712 | while (*e) { |
2713 | type = *e++; |
2714 | n = 0; |
2715 | while (*e && *e != '\t') |
2716 | sports[n++] = *e++; |
2717 | sports[n] = 0; |
2718 | if (*e == '\t') |
2719 | e++; |
2720 | n = 0; |
2721 | while (*e && *e != ':') |
2722 | host[n++] = *e++; |
2723 | host[n] = 0; |
2724 | if (*e == ':') |
2725 | e++; |
2726 | n = 0; |
2727 | while (*e) |
2728 | dports[n++] = *e++; |
2729 | dports[n] = 0; |
2730 | e++; |
2731 | dport = atoi(dports); |
2732 | sport = atoi(sports); |
2733 | if (sport && dport) { |
2734 | if (type == 'L') { |
2735 | pfd_addforward(host, dport, sport); |
2736 | sprintf(buf, "Local port %d forwarding to %s:%d", |
2737 | sport, host, dport); |
2738 | logevent(buf); |
2739 | } else { |
2740 | struct ssh_rportfwd *pf; |
2741 | pf = smalloc(sizeof(*pf)); |
bc240b21 |
2742 | strcpy(pf->dhost, host); |
2743 | pf->dport = dport; |
d74d141c |
2744 | if (add234(ssh_rportfwds, pf) != pf) { |
2745 | sprintf(buf, |
95bc8819 |
2746 | "Duplicate remote port forwarding to %s:%d", |
d74d141c |
2747 | host, dport); |
2748 | logevent(buf); |
bc240b21 |
2749 | sfree(pf); |
d74d141c |
2750 | } else { |
2751 | sprintf(buf, "Requesting remote port %d forward to %s:%d", |
2752 | sport, host, dport); |
2753 | logevent(buf); |
2754 | send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST, |
2755 | PKT_INT, sport, |
2756 | PKT_STR, host, |
2757 | PKT_INT, dport, |
2758 | PKT_END); |
2759 | } |
2760 | } |
2761 | } |
2762 | } |
2763 | } |
2764 | |
fef97f43 |
2765 | if (!cfg.nopty) { |
e5574168 |
2766 | send_packet(SSH1_CMSG_REQUEST_PTY, |
32874aea |
2767 | PKT_STR, cfg.termtype, |
2768 | PKT_INT, rows, PKT_INT, cols, |
2769 | PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END); |
2770 | ssh_state = SSH_STATE_INTERMED; |
2771 | do { |
2772 | crReturnV; |
2773 | } while (!ispkt); |
2774 | if (pktin.type != SSH1_SMSG_SUCCESS |
2775 | && pktin.type != SSH1_SMSG_FAILURE) { |
2776 | bombout(("Protocol confusion")); |
2777 | crReturnV; |
2778 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
2779 | c_write_str("Server refused to allocate pty\r\n"); |
2780 | ssh_editing = ssh_echoing = 1; |
2781 | } |
c5e9c988 |
2782 | logevent("Allocated pty"); |
0965bee0 |
2783 | } else { |
32874aea |
2784 | ssh_editing = ssh_echoing = 1; |
374330e2 |
2785 | } |
2786 | |
4ba9b64b |
2787 | if (cfg.compression) { |
32874aea |
2788 | send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END); |
2789 | do { |
2790 | crReturnV; |
2791 | } while (!ispkt); |
2792 | if (pktin.type != SSH1_SMSG_SUCCESS |
2793 | && pktin.type != SSH1_SMSG_FAILURE) { |
2794 | bombout(("Protocol confusion")); |
2795 | crReturnV; |
2796 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
2797 | c_write_str("Server refused to compress\r\n"); |
2798 | } |
4ba9b64b |
2799 | logevent("Started compression"); |
2800 | ssh1_compressing = TRUE; |
2801 | zlib_compress_init(); |
2802 | zlib_decompress_init(); |
2803 | } |
2804 | |
fd5e5847 |
2805 | /* |
2806 | * Start the shell or command. |
2807 | * |
2808 | * Special case: if the first-choice command is an SSH2 |
2809 | * subsystem (hence not usable here) and the second choice |
2810 | * exists, we fall straight back to that. |
2811 | */ |
2812 | { |
2813 | char *cmd = cfg.remote_cmd_ptr; |
2814 | |
2815 | if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) { |
2816 | cmd = cfg.remote_cmd_ptr2; |
2817 | ssh_fallback_cmd = TRUE; |
2818 | } |
2819 | if (*cmd) |
2820 | send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END); |
2821 | else |
2822 | send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END); |
2823 | logevent("Started session"); |
2824 | } |
374330e2 |
2825 | |
2826 | ssh_state = SSH_STATE_SESSION; |
2827 | if (size_needed) |
2828 | ssh_size(); |
3687d221 |
2829 | if (eof_needed) |
32874aea |
2830 | ssh_special(TS_EOF); |
374330e2 |
2831 | |
760e88b2 |
2832 | ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */ |
8ccc75b0 |
2833 | ssh_send_ok = 1; |
dacbd0e8 |
2834 | ssh_channels = newtree234(ssh_channelcmp); |
374330e2 |
2835 | while (1) { |
2836 | crReturnV; |
2837 | if (ispkt) { |
e5574168 |
2838 | if (pktin.type == SSH1_SMSG_STDOUT_DATA || |
32874aea |
2839 | pktin.type == SSH1_SMSG_STDERR_DATA) { |
fb09bf1c |
2840 | long len = GET_32BIT(pktin.body); |
5471d09a |
2841 | int bufsize = |
2842 | from_backend(pktin.type == SSH1_SMSG_STDERR_DATA, |
2843 | pktin.body + 4, len); |
90347b95 |
2844 | if (!ssh1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) { |
5471d09a |
2845 | ssh1_stdout_throttling = 1; |
2846 | ssh1_throttle(+1); |
2847 | } |
e5574168 |
2848 | } else if (pktin.type == SSH1_MSG_DISCONNECT) { |
32874aea |
2849 | ssh_state = SSH_STATE_CLOSED; |
c5e9c988 |
2850 | logevent("Received disconnect request"); |
32874aea |
2851 | crReturnV; |
2852 | } else if (pktin.type == SSH1_SMSG_X11_OPEN) { |
2853 | /* Remote side is trying to open a channel to talk to our |
2854 | * X-Server. Give them back a local channel number. */ |
2855 | struct ssh_channel *c; |
9c964e85 |
2856 | |
2857 | logevent("Received X11 connect request"); |
2858 | /* Refuse if X11 forwarding is disabled. */ |
2859 | if (!ssh_X11_fwd_enabled) { |
2860 | send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE, |
32874aea |
2861 | PKT_INT, GET_32BIT(pktin.body), PKT_END); |
9c964e85 |
2862 | logevent("Rejected X11 connect request"); |
2863 | } else { |
9c964e85 |
2864 | c = smalloc(sizeof(struct ssh_channel)); |
2865 | |
32874aea |
2866 | if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) { |
2867 | logevent("opening X11 forward connection failed"); |
2868 | sfree(c); |
2869 | send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE, |
2870 | PKT_INT, GET_32BIT(pktin.body), |
2871 | PKT_END); |
9c964e85 |
2872 | } else { |
32874aea |
2873 | logevent |
2874 | ("opening X11 forward connection succeeded"); |
2875 | c->remoteid = GET_32BIT(pktin.body); |
2876 | c->localid = alloc_channel_id(); |
2877 | c->closes = 0; |
5471d09a |
2878 | c->v.v1.throttling = 0; |
32874aea |
2879 | c->type = CHAN_X11; /* identify channel type */ |
2880 | add234(ssh_channels, c); |
2881 | send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, |
2882 | PKT_INT, c->remoteid, PKT_INT, |
2883 | c->localid, PKT_END); |
2884 | logevent("Opened X11 forward channel"); |
9c964e85 |
2885 | } |
2886 | } |
32874aea |
2887 | } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) { |
2888 | /* Remote side is trying to open a channel to talk to our |
2889 | * agent. Give them back a local channel number. */ |
2890 | struct ssh_channel *c; |
db7d555c |
2891 | |
2892 | /* Refuse if agent forwarding is disabled. */ |
2893 | if (!ssh_agentfwd_enabled) { |
2894 | send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE, |
32874aea |
2895 | PKT_INT, GET_32BIT(pktin.body), PKT_END); |
db7d555c |
2896 | } else { |
dcbde236 |
2897 | c = smalloc(sizeof(struct ssh_channel)); |
db7d555c |
2898 | c->remoteid = GET_32BIT(pktin.body); |
d2371c81 |
2899 | c->localid = alloc_channel_id(); |
db7d555c |
2900 | c->closes = 0; |
5471d09a |
2901 | c->v.v1.throttling = 0; |
32874aea |
2902 | c->type = CHAN_AGENT; /* identify channel type */ |
db7d555c |
2903 | c->u.a.lensofar = 0; |
2904 | add234(ssh_channels, c); |
2905 | send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, |
2906 | PKT_INT, c->remoteid, PKT_INT, c->localid, |
2907 | PKT_END); |
2908 | } |
d74d141c |
2909 | } else if (pktin.type == SSH1_MSG_PORT_OPEN) { |
2910 | /* Remote side is trying to open a channel to talk to a |
2911 | * forwarded port. Give them back a local channel number. */ |
2912 | struct ssh_channel *c; |
2913 | struct ssh_rportfwd pf; |
2914 | int hostsize, port; |
2915 | char host[256], buf[1024]; |
2916 | char *p, *h, *e; |
2917 | c = smalloc(sizeof(struct ssh_channel)); |
2918 | |
2919 | hostsize = GET_32BIT(pktin.body+4); |
2920 | for(h = host, p = pktin.body+8; hostsize != 0; hostsize--) { |
2921 | if (h+1 < host+sizeof(host)) |
2922 | *h++ = *p; |
95bc8819 |
2923 | p++; |
d74d141c |
2924 | } |
2925 | *h = 0; |
2926 | port = GET_32BIT(p); |
2927 | |
bc240b21 |
2928 | strcpy(pf.dhost, host); |
2929 | pf.dport = port; |
d74d141c |
2930 | |
2931 | if (find234(ssh_rportfwds, &pf, NULL) == NULL) { |
2932 | sprintf(buf, "Rejected remote port open request for %s:%d", |
2933 | host, port); |
2934 | logevent(buf); |
2935 | send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE, |
2936 | PKT_INT, GET_32BIT(pktin.body), PKT_END); |
2937 | } else { |
2938 | sprintf(buf, "Received remote port open request for %s:%d", |
2939 | host, port); |
2940 | logevent(buf); |
2941 | e = pfd_newconnect(&c->u.pfd.s, host, port, c); |
2942 | if (e != NULL) { |
2943 | char buf[256]; |
2944 | sprintf(buf, "Port open failed: %s", e); |
2945 | logevent(buf); |
2946 | sfree(c); |
2947 | send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE, |
2948 | PKT_INT, GET_32BIT(pktin.body), |
2949 | PKT_END); |
2950 | } else { |
2951 | c->remoteid = GET_32BIT(pktin.body); |
2952 | c->localid = alloc_channel_id(); |
2953 | c->closes = 0; |
5471d09a |
2954 | c->v.v1.throttling = 0; |
d74d141c |
2955 | c->type = CHAN_SOCKDATA; /* identify channel type */ |
2956 | add234(ssh_channels, c); |
2957 | send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, |
2958 | PKT_INT, c->remoteid, PKT_INT, |
2959 | c->localid, PKT_END); |
2960 | logevent("Forwarded port opened successfully"); |
2961 | } |
2962 | } |
2963 | |
2964 | } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) { |
bc240b21 |
2965 | unsigned int remoteid = GET_32BIT(pktin.body); |
2966 | unsigned int localid = GET_32BIT(pktin.body+4); |
2967 | struct ssh_channel *c; |
2968 | |
2969 | c = find234(ssh_channels, &remoteid, ssh_channelfind); |
2970 | if (c && c->type == CHAN_SOCKDATA_DORMANT) { |
2971 | c->remoteid = localid; |
2972 | c->type = CHAN_SOCKDATA; |
7781f316 |
2973 | c->v.v1.throttling = 0; |
bc240b21 |
2974 | pfd_confirm(c->u.pfd.s); |
2975 | } |
d74d141c |
2976 | |
4ed34d25 |
2977 | if (c && c->closes) { |
2978 | /* |
2979 | * We have a pending close on this channel, |
2980 | * which we decided on before the server acked |
2981 | * the channel open. So now we know the |
2982 | * remoteid, we can close it again. |
2983 | */ |
2984 | send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, |
2985 | PKT_END); |
2986 | } |
2987 | |
724cface |
2988 | } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) { |
2989 | unsigned int remoteid = GET_32BIT(pktin.body); |
2990 | unsigned int localid = GET_32BIT(pktin.body+4); |
2991 | struct ssh_channel *c; |
2992 | |
2993 | c = find234(ssh_channels, &remoteid, ssh_channelfind); |
2994 | if (c && c->type == CHAN_SOCKDATA_DORMANT) { |
2995 | logevent("Forwarded connection refused by server"); |
2996 | pfd_close(c->u.pfd.s); |
2997 | del234(ssh_channels, c); |
2998 | sfree(c); |
2999 | } |
3000 | |
db7d555c |
3001 | } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE || |
3002 | pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) { |
32874aea |
3003 | /* Remote side closes a channel. */ |
3004 | unsigned i = GET_32BIT(pktin.body); |
3005 | struct ssh_channel *c; |
3006 | c = find234(ssh_channels, &i, ssh_channelfind); |
3007 | if (c) { |
3008 | int closetype; |
3009 | closetype = |
3010 | (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2); |
3011 | if (!(c->closes & closetype)) |
3012 | send_packet(pktin.type, PKT_INT, c->remoteid, |
3013 | PKT_END); |
783415f8 |
3014 | if ((c->closes == 0) && (c->type == CHAN_X11)) { |
d74d141c |
3015 | logevent("Forwarded X11 connection terminated"); |
9c964e85 |
3016 | assert(c->u.x11.s != NULL); |
3017 | x11_close(c->u.x11.s); |
3018 | c->u.x11.s = NULL; |
3019 | } |
d74d141c |
3020 | if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) { |
3021 | logevent("Forwarded port closed"); |
3022 | assert(c->u.pfd.s != NULL); |
3023 | pfd_close(c->u.pfd.s); |
3024 | c->u.pfd.s = NULL; |
3025 | } |
32874aea |
3026 | c->closes |= closetype; |
3027 | if (c->closes == 3) { |
3028 | del234(ssh_channels, c); |
3029 | sfree(c); |
3030 | } |
3031 | } |
3032 | } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) { |
3033 | /* Data sent down one of our channels. */ |
3034 | int i = GET_32BIT(pktin.body); |
3035 | int len = GET_32BIT(pktin.body + 4); |
3036 | unsigned char *p = pktin.body + 8; |
3037 | struct ssh_channel *c; |
3038 | c = find234(ssh_channels, &i, ssh_channelfind); |
3039 | if (c) { |
5471d09a |
3040 | int bufsize; |
32874aea |
3041 | switch (c->type) { |
3042 | case CHAN_X11: |
5471d09a |
3043 | bufsize = x11_send(c->u.x11.s, p, len); |
9c964e85 |
3044 | break; |
d74d141c |
3045 | case CHAN_SOCKDATA: |
5471d09a |
3046 | bufsize = pfd_send(c->u.pfd.s, p, len); |
bc240b21 |
3047 | break; |
32874aea |
3048 | case CHAN_AGENT: |
3049 | /* Data for an agent message. Buffer it. */ |
3050 | while (len > 0) { |
3051 | if (c->u.a.lensofar < 4) { |
3052 | int l = min(4 - c->u.a.lensofar, len); |
3053 | memcpy(c->u.a.msglen + c->u.a.lensofar, p, |
3054 | l); |
3055 | p += l; |
3056 | len -= l; |
3057 | c->u.a.lensofar += l; |
3058 | } |
3059 | if (c->u.a.lensofar == 4) { |
3060 | c->u.a.totallen = |
3061 | 4 + GET_32BIT(c->u.a.msglen); |
3062 | c->u.a.message = smalloc(c->u.a.totallen); |
3063 | memcpy(c->u.a.message, c->u.a.msglen, 4); |
3064 | } |
3065 | if (c->u.a.lensofar >= 4 && len > 0) { |
3066 | int l = |
3067 | min(c->u.a.totallen - c->u.a.lensofar, |
3068 | len); |
3069 | memcpy(c->u.a.message + c->u.a.lensofar, p, |
3070 | l); |
3071 | p += l; |
3072 | len -= l; |
3073 | c->u.a.lensofar += l; |
3074 | } |
3075 | if (c->u.a.lensofar == c->u.a.totallen) { |
3076 | void *reply, *sentreply; |
3077 | int replylen; |
3078 | agent_query(c->u.a.message, |
3079 | c->u.a.totallen, &reply, |
3080 | &replylen); |
3081 | if (reply) |
3082 | sentreply = reply; |
3083 | else { |
3084 | /* Fake SSH_AGENT_FAILURE. */ |
3085 | sentreply = "\0\0\0\1\5"; |
3086 | replylen = 5; |
3087 | } |
3088 | send_packet(SSH1_MSG_CHANNEL_DATA, |
3089 | PKT_INT, c->remoteid, |
3090 | PKT_INT, replylen, |
3091 | PKT_DATA, sentreply, replylen, |
3092 | PKT_END); |
3093 | if (reply) |
3094 | sfree(reply); |
3095 | sfree(c->u.a.message); |
3096 | c->u.a.lensofar = 0; |
3097 | } |
3098 | } |
5471d09a |
3099 | bufsize = 0; /* agent channels never back up */ |
32874aea |
3100 | break; |
3101 | } |
90347b95 |
3102 | if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) { |
5471d09a |
3103 | c->v.v1.throttling = 1; |
3104 | ssh1_throttle(+1); |
3105 | } |
32874aea |
3106 | } |
e5574168 |
3107 | } else if (pktin.type == SSH1_SMSG_SUCCESS) { |
972a41c8 |
3108 | /* may be from EXEC_SHELL on some servers */ |
e5574168 |
3109 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
972a41c8 |
3110 | /* may be from EXEC_SHELL on some servers |
374330e2 |
3111 | * if no pty is available or in other odd cases. Ignore */ |
e5574168 |
3112 | } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) { |
3113 | send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END); |
4252c9cc |
3114 | /* |
3115 | * In case `helpful' firewalls or proxies tack |
3116 | * extra human-readable text on the end of the |
3117 | * session which we might mistake for another |
3118 | * encrypted packet, we close the session once |
3119 | * we've sent EXIT_CONFIRMATION. |
3120 | */ |
3121 | ssh_state = SSH_STATE_CLOSED; |
3122 | crReturnV; |
374330e2 |
3123 | } else { |
8d5de777 |
3124 | bombout(("Strange packet received: type %d", pktin.type)); |
32874aea |
3125 | crReturnV; |
374330e2 |
3126 | } |
3127 | } else { |
8df7a775 |
3128 | while (inlen > 0) { |
3129 | int len = min(inlen, 512); |
3130 | send_packet(SSH1_CMSG_STDIN_DATA, |
3131 | PKT_INT, len, PKT_DATA, in, len, PKT_END); |
3132 | in += len; |
3133 | inlen -= len; |
3134 | } |
374330e2 |
3135 | } |
3136 | } |
3137 | |
3138 | crFinishV; |
3139 | } |
3140 | |
3141 | /* |
e5574168 |
3142 | * Utility routine for decoding comma-separated strings in KEXINIT. |
3143 | */ |
32874aea |
3144 | static int in_commasep_string(char *needle, char *haystack, int haylen) |
3145 | { |
e5574168 |
3146 | int needlen = strlen(needle); |
3147 | while (1) { |
32874aea |
3148 | /* |
3149 | * Is it at the start of the string? |
3150 | */ |
3151 | if (haylen >= needlen && /* haystack is long enough */ |
3152 | !memcmp(needle, haystack, needlen) && /* initial match */ |
3153 | (haylen == needlen || haystack[needlen] == ',') |
3154 | /* either , or EOS follows */ |
3155 | ) |
3156 | return 1; |
3157 | /* |
3158 | * If not, search for the next comma and resume after that. |
3159 | * If no comma found, terminate. |
3160 | */ |
3161 | while (haylen > 0 && *haystack != ',') |
3162 | haylen--, haystack++; |
3163 | if (haylen == 0) |
3164 | return 0; |
3165 | haylen--, haystack++; /* skip over comma itself */ |
e5574168 |
3166 | } |
3167 | } |
3168 | |
3169 | /* |
d39f364a |
3170 | * SSH2 key creation method. |
3171 | */ |
32874aea |
3172 | static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr, |
3173 | char *keyspace) |
3174 | { |
d39f364a |
3175 | SHA_State s; |
3176 | /* First 20 bytes. */ |
3177 | SHA_Init(&s); |
3178 | sha_mpint(&s, K); |
3179 | SHA_Bytes(&s, H, 20); |
3180 | SHA_Bytes(&s, &chr, 1); |
5e0d7cb8 |
3181 | SHA_Bytes(&s, sessid, 20); |
d39f364a |
3182 | SHA_Final(&s, keyspace); |
3183 | /* Next 20 bytes. */ |
3184 | SHA_Init(&s); |
3185 | sha_mpint(&s, K); |
3186 | SHA_Bytes(&s, H, 20); |
3187 | SHA_Bytes(&s, keyspace, 20); |
32874aea |
3188 | SHA_Final(&s, keyspace + 20); |
d39f364a |
3189 | } |
3190 | |
3191 | /* |
7cca0d81 |
3192 | * Handle the SSH2 transport layer. |
e5574168 |
3193 | */ |
7cca0d81 |
3194 | static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt) |
e5574168 |
3195 | { |
ca20bfcf |
3196 | static int i, j, len, nbits, pbits, warn; |
e5574168 |
3197 | static char *str; |
a92dd380 |
3198 | static Bignum p, g, e, f, K; |
3199 | static int kex_init_value, kex_reply_value; |
7591b9ff |
3200 | static const struct ssh_mac **maclist; |
8b2715b2 |
3201 | static int nmacs; |
0a3f1d48 |
3202 | static const struct ssh2_cipher *cscipher_tobe = NULL; |
3203 | static const struct ssh2_cipher *sccipher_tobe = NULL; |
57476f6b |
3204 | static const struct ssh_mac *csmac_tobe = NULL; |
3205 | static const struct ssh_mac *scmac_tobe = NULL; |
3206 | static const struct ssh_compress *cscomp_tobe = NULL; |
3207 | static const struct ssh_compress *sccomp_tobe = NULL; |
d5859615 |
3208 | static char *hostkeydata, *sigdata, *keystr, *fingerprint; |
e5574168 |
3209 | static int hostkeylen, siglen; |
e055a386 |
3210 | static void *hkey; /* actual host key */ |
e5574168 |
3211 | static unsigned char exchange_hash[20]; |
d39f364a |
3212 | static unsigned char keyspace[40]; |
ca20bfcf |
3213 | static int n_preferred_ciphers; |
3214 | static const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX]; |
4ba9b64b |
3215 | static const struct ssh_compress *preferred_comp; |
087abe1a |
3216 | static int cipherstr_started; |
0db56f73 |
3217 | static int first_kex; |
e5574168 |
3218 | |
3219 | crBegin; |
7cca0d81 |
3220 | random_init(); |
0db56f73 |
3221 | first_kex = 1; |
e5574168 |
3222 | |
5e8358ad |
3223 | /* |
ca20bfcf |
3224 | * Set up the preferred ciphers. (NULL => warn below here) |
5e8358ad |
3225 | */ |
ca20bfcf |
3226 | n_preferred_ciphers = 0; |
3227 | for (i = 0; i < CIPHER_MAX; i++) { |
3228 | switch (cfg.ssh_cipherlist[i]) { |
3229 | case CIPHER_BLOWFISH: |
3230 | preferred_ciphers[n_preferred_ciphers] = &ssh2_blowfish; |
3231 | n_preferred_ciphers++; |
3232 | break; |
3233 | case CIPHER_DES: |
087abe1a |
3234 | if (cfg.ssh2_des_cbc) { |
3235 | preferred_ciphers[n_preferred_ciphers] = &ssh2_des; |
3236 | n_preferred_ciphers++; |
3237 | } |
ca20bfcf |
3238 | break; |
3239 | case CIPHER_3DES: |
3240 | preferred_ciphers[n_preferred_ciphers] = &ssh2_3des; |
3241 | n_preferred_ciphers++; |
3242 | break; |
3243 | case CIPHER_AES: |
3244 | preferred_ciphers[n_preferred_ciphers] = &ssh2_aes; |
3245 | n_preferred_ciphers++; |
3246 | break; |
3247 | case CIPHER_WARN: |
3248 | /* Flag for later. Don't bother if it's the last in |
3249 | * the list. */ |
3250 | if (i < CIPHER_MAX - 1) { |
3251 | preferred_ciphers[n_preferred_ciphers] = NULL; |
3252 | n_preferred_ciphers++; |
3253 | } |
3254 | break; |
3255 | } |
5e8358ad |
3256 | } |
ca20bfcf |
3257 | |
3258 | /* |
3259 | * Set up preferred compression. |
3260 | */ |
4ba9b64b |
3261 | if (cfg.compression) |
3262 | preferred_comp = &ssh_zlib; |
3263 | else |
3264 | preferred_comp = &ssh_comp_none; |
5e8358ad |
3265 | |
7591b9ff |
3266 | /* |
3267 | * Be prepared to work around the buggy MAC problem. |
3268 | */ |
7d503c31 |
3269 | if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC)) |
32874aea |
3270 | maclist = buggymacs, nmacs = lenof(buggymacs); |
7591b9ff |
3271 | else |
32874aea |
3272 | maclist = macs, nmacs = lenof(macs); |
7591b9ff |
3273 | |
32874aea |
3274 | begin_key_exchange: |
e5574168 |
3275 | /* |
3276 | * Construct and send our key exchange packet. |
3277 | */ |
3278 | ssh2_pkt_init(SSH2_MSG_KEXINIT); |
3279 | for (i = 0; i < 16; i++) |
32874aea |
3280 | ssh2_pkt_addbyte((unsigned char) random_byte()); |
e5574168 |
3281 | /* List key exchange algorithms. */ |
3282 | ssh2_pkt_addstring_start(); |
3283 | for (i = 0; i < lenof(kex_algs); i++) { |
32874aea |
3284 | ssh2_pkt_addstring_str(kex_algs[i]->name); |
3285 | if (i < lenof(kex_algs) - 1) |
3286 | ssh2_pkt_addstring_str(","); |
e5574168 |
3287 | } |
3288 | /* List server host key algorithms. */ |
3289 | ssh2_pkt_addstring_start(); |
3290 | for (i = 0; i < lenof(hostkey_algs); i++) { |
32874aea |
3291 | ssh2_pkt_addstring_str(hostkey_algs[i]->name); |
3292 | if (i < lenof(hostkey_algs) - 1) |
3293 | ssh2_pkt_addstring_str(","); |
e5574168 |
3294 | } |
3295 | /* List client->server encryption algorithms. */ |
3296 | ssh2_pkt_addstring_start(); |
087abe1a |
3297 | cipherstr_started = 0; |
ca20bfcf |
3298 | for (i = 0; i < n_preferred_ciphers; i++) { |
3299 | const struct ssh2_ciphers *c = preferred_ciphers[i]; |
3300 | if (!c) continue; /* warning flag */ |
32874aea |
3301 | for (j = 0; j < c->nciphers; j++) { |
087abe1a |
3302 | if (cipherstr_started) |
32874aea |
3303 | ssh2_pkt_addstring_str(","); |
087abe1a |
3304 | ssh2_pkt_addstring_str(c->list[j]->name); |
3305 | cipherstr_started = 1; |
32874aea |
3306 | } |
e5574168 |
3307 | } |
3308 | /* List server->client encryption algorithms. */ |
3309 | ssh2_pkt_addstring_start(); |
087abe1a |
3310 | cipherstr_started = 0; |
ca20bfcf |
3311 | for (i = 0; i < n_preferred_ciphers; i++) { |
3312 | const struct ssh2_ciphers *c = preferred_ciphers[i]; |
3313 | if (!c) continue; /* warning flag */ |
32874aea |
3314 | for (j = 0; j < c->nciphers; j++) { |
087abe1a |
3315 | if (cipherstr_started) |
32874aea |
3316 | ssh2_pkt_addstring_str(","); |
087abe1a |
3317 | ssh2_pkt_addstring_str(c->list[j]->name); |
3318 | cipherstr_started = 1; |
32874aea |
3319 | } |
e5574168 |
3320 | } |
3321 | /* List client->server MAC algorithms. */ |
3322 | ssh2_pkt_addstring_start(); |
8b2715b2 |
3323 | for (i = 0; i < nmacs; i++) { |
32874aea |
3324 | ssh2_pkt_addstring_str(maclist[i]->name); |
3325 | if (i < nmacs - 1) |
3326 | ssh2_pkt_addstring_str(","); |
e5574168 |
3327 | } |
3328 | /* List server->client MAC algorithms. */ |
3329 | ssh2_pkt_addstring_start(); |
8b2715b2 |
3330 | for (i = 0; i < nmacs; i++) { |
32874aea |
3331 | ssh2_pkt_addstring_str(maclist[i]->name); |
3332 | if (i < nmacs - 1) |
3333 | ssh2_pkt_addstring_str(","); |
e5574168 |
3334 | } |
3335 | /* List client->server compression algorithms. */ |
3336 | ssh2_pkt_addstring_start(); |
32874aea |
3337 | for (i = 0; i < lenof(compressions) + 1; i++) { |
3338 | const struct ssh_compress *c = |
3339 | i == 0 ? preferred_comp : compressions[i - 1]; |
3340 | ssh2_pkt_addstring_str(c->name); |
3341 | if (i < lenof(compressions)) |
3342 | ssh2_pkt_addstring_str(","); |
e5574168 |
3343 | } |
3344 | /* List server->client compression algorithms. */ |
3345 | ssh2_pkt_addstring_start(); |
32874aea |
3346 | for (i = 0; i < lenof(compressions) + 1; i++) { |
3347 | const struct ssh_compress *c = |
3348 | i == 0 ? preferred_comp : compressions[i - 1]; |
3349 | ssh2_pkt_addstring_str(c->name); |
3350 | if (i < lenof(compressions)) |
3351 | ssh2_pkt_addstring_str(","); |
e5574168 |
3352 | } |
3353 | /* List client->server languages. Empty list. */ |
3354 | ssh2_pkt_addstring_start(); |
3355 | /* List server->client languages. Empty list. */ |
3356 | ssh2_pkt_addstring_start(); |
3357 | /* First KEX packet does _not_ follow, because we're not that brave. */ |
3358 | ssh2_pkt_addbool(FALSE); |
3359 | /* Reserved. */ |
3360 | ssh2_pkt_adduint32(0); |
0db56f73 |
3361 | |
3362 | exhash = exhashbase; |
32874aea |
3363 | sha_string(&exhash, pktout.data + 5, pktout.length - 5); |
0db56f73 |
3364 | |
e5574168 |
3365 | ssh2_pkt_send(); |
3366 | |
32874aea |
3367 | if (!ispkt) |
3368 | crWaitUntil(ispkt); |
3369 | sha_string(&exhash, pktin.data + 5, pktin.length - 5); |
e5574168 |
3370 | |
3371 | /* |
3372 | * Now examine the other side's KEXINIT to see what we're up |
3373 | * to. |
3374 | */ |
7cca0d81 |
3375 | if (pktin.type != SSH2_MSG_KEXINIT) { |
32874aea |
3376 | bombout(("expected key exchange packet from server")); |
3377 | crReturn(0); |
7cca0d81 |
3378 | } |
32874aea |
3379 | kex = NULL; |
3380 | hostkey = NULL; |
3381 | cscipher_tobe = NULL; |
3382 | sccipher_tobe = NULL; |
3383 | csmac_tobe = NULL; |
3384 | scmac_tobe = NULL; |
3385 | cscomp_tobe = NULL; |
3386 | sccomp_tobe = NULL; |
3387 | pktin.savedpos += 16; /* skip garbage cookie */ |
e5574168 |
3388 | ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */ |
3389 | for (i = 0; i < lenof(kex_algs); i++) { |
32874aea |
3390 | if (in_commasep_string(kex_algs[i]->name, str, len)) { |
3391 | kex = kex_algs[i]; |
3392 | break; |
3393 | } |
e5574168 |
3394 | } |
3395 | ssh2_pkt_getstring(&str, &len); /* host key algorithms */ |
3396 | for (i = 0; i < lenof(hostkey_algs); i++) { |
32874aea |
3397 | if (in_commasep_string(hostkey_algs[i]->name, str, len)) { |
3398 | hostkey = hostkey_algs[i]; |
3399 | break; |
3400 | } |
e5574168 |
3401 | } |
3402 | ssh2_pkt_getstring(&str, &len); /* client->server cipher */ |
ca20bfcf |
3403 | warn = 0; |
3404 | for (i = 0; i < n_preferred_ciphers; i++) { |
3405 | const struct ssh2_ciphers *c = preferred_ciphers[i]; |
3406 | if (!c) { |
3407 | warn = 1; |
3408 | } else { |
3409 | for (j = 0; j < c->nciphers; j++) { |
3410 | if (in_commasep_string(c->list[j]->name, str, len)) { |
3411 | cscipher_tobe = c->list[j]; |
3412 | break; |
3413 | } |
32874aea |
3414 | } |
3415 | } |
ca20bfcf |
3416 | if (cscipher_tobe) { |
3417 | if (warn) |
3418 | askcipher(cscipher_tobe->name, 1); |
32874aea |
3419 | break; |
ca20bfcf |
3420 | } |
e5574168 |
3421 | } |
0ef8f407 |
3422 | if (!cscipher_tobe) { |
3423 | bombout(("Couldn't agree a client-to-server cipher (available: %s)", str)); |
3424 | crReturn(0); |
3425 | } |
3426 | |
e5574168 |
3427 | ssh2_pkt_getstring(&str, &len); /* server->client cipher */ |
ca20bfcf |
3428 | warn = 0; |
3429 | for (i = 0; i < n_preferred_ciphers; i++) { |
3430 | const struct ssh2_ciphers *c = preferred_ciphers[i]; |
3431 | if (!c) { |
3432 | warn = 1; |
3433 | } else { |
3434 | for (j = 0; j < c->nciphers; j++) { |
3435 | if (in_commasep_string(c->list[j]->name, str, len)) { |
3436 | sccipher_tobe = c->list[j]; |
3437 | break; |
3438 | } |
32874aea |
3439 | } |
3440 | } |
ca20bfcf |
3441 | if (sccipher_tobe) { |
3442 | if (warn) |
3443 | askcipher(sccipher_tobe->name, 2); |
32874aea |
3444 | break; |
ca20bfcf |
3445 | } |
e5574168 |
3446 | } |
0ef8f407 |
3447 | if (!sccipher_tobe) { |
3448 | bombout(("Couldn't agree a server-to-client cipher (available: %s)", str)); |
3449 | crReturn(0); |
3450 | } |
3451 | |
e5574168 |
3452 | ssh2_pkt_getstring(&str, &len); /* client->server mac */ |
8b2715b2 |
3453 | for (i = 0; i < nmacs; i++) { |
32874aea |
3454 | if (in_commasep_string(maclist[i]->name, str, len)) { |
3455 | csmac_tobe = maclist[i]; |
3456 | break; |
3457 | } |
e5574168 |
3458 | } |
3459 | ssh2_pkt_getstring(&str, &len); /* server->client mac */ |
8b2715b2 |
3460 | for (i = 0; i < nmacs; i++) { |
32874aea |
3461 | if (in_commasep_string(maclist[i]->name, str, len)) { |
3462 | scmac_tobe = maclist[i]; |
3463 | break; |
3464 | } |
e5574168 |
3465 | } |
3466 | ssh2_pkt_getstring(&str, &len); /* client->server compression */ |
32874aea |
3467 | for (i = 0; i < lenof(compressions) + 1; i++) { |
3468 | const struct ssh_compress *c = |
3469 | i == 0 ? preferred_comp : compressions[i - 1]; |
3470 | if (in_commasep_string(c->name, str, len)) { |
3471 | cscomp_tobe = c; |
3472 | break; |
3473 | } |
e5574168 |
3474 | } |
3475 | ssh2_pkt_getstring(&str, &len); /* server->client compression */ |
32874aea |
3476 | for (i = 0; i < lenof(compressions) + 1; i++) { |
3477 | const struct ssh_compress *c = |
3478 | i == 0 ? preferred_comp : compressions[i - 1]; |
3479 | if (in_commasep_string(c->name, str, len)) { |
3480 | sccomp_tobe = c; |
3481 | break; |
3482 | } |
e5574168 |
3483 | } |
e5574168 |
3484 | |
3485 | /* |
7bd5a860 |
3486 | * Work out the number of bits of key we will need from the key |
3487 | * exchange. We start with the maximum key length of either |
3488 | * cipher... |
3489 | */ |
3490 | { |
32874aea |
3491 | int csbits, scbits; |
7bd5a860 |
3492 | |
3493 | csbits = cscipher_tobe->keylen; |
3494 | scbits = sccipher_tobe->keylen; |
3495 | nbits = (csbits > scbits ? csbits : scbits); |
3496 | } |
3497 | /* The keys only have 160-bit entropy, since they're based on |
3498 | * a SHA-1 hash. So cap the key size at 160 bits. */ |
32874aea |
3499 | if (nbits > 160) |
3500 | nbits = 160; |
7bd5a860 |
3501 | |
3502 | /* |
a92dd380 |
3503 | * If we're doing Diffie-Hellman group exchange, start by |
3504 | * requesting a group. |
e5574168 |
3505 | */ |
a92dd380 |
3506 | if (kex == &ssh_diffiehellman_gex) { |
32874aea |
3507 | logevent("Doing Diffie-Hellman group exchange"); |
00db133f |
3508 | ssh_pkt_ctx |= SSH2_PKTCTX_DHGEX; |
32874aea |
3509 | /* |
3510 | * Work out how big a DH group we will need to allow that |
3511 | * much data. |
7bd5a860 |
3512 | */ |
32874aea |
3513 | pbits = 512 << ((nbits - 1) / 64); |
3514 | ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST); |
3515 | ssh2_pkt_adduint32(pbits); |
3516 | ssh2_pkt_send(); |
3517 | |
3518 | crWaitUntil(ispkt); |
3519 | if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) { |
3520 | bombout(("expected key exchange group packet from server")); |
3521 | crReturn(0); |
3522 | } |
3523 | p = ssh2_pkt_getmp(); |
3524 | g = ssh2_pkt_getmp(); |
3525 | dh_setup_group(p, g); |
3526 | kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT; |
3527 | kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY; |
a92dd380 |
3528 | } else { |
00db133f |
3529 | ssh_pkt_ctx |= SSH2_PKTCTX_DHGROUP1; |
32874aea |
3530 | dh_setup_group1(); |
3531 | kex_init_value = SSH2_MSG_KEXDH_INIT; |
3532 | kex_reply_value = SSH2_MSG_KEXDH_REPLY; |
8d5de777 |
3533 | } |
e5574168 |
3534 | |
a92dd380 |
3535 | logevent("Doing Diffie-Hellman key exchange"); |
e5574168 |
3536 | /* |
a92dd380 |
3537 | * Now generate and send e for Diffie-Hellman. |
e5574168 |
3538 | */ |
32874aea |
3539 | e = dh_create_e(nbits * 2); |
a92dd380 |
3540 | ssh2_pkt_init(kex_init_value); |
e5574168 |
3541 | ssh2_pkt_addmp(e); |
3542 | ssh2_pkt_send(); |
3543 | |
3544 | crWaitUntil(ispkt); |
a92dd380 |
3545 | if (pktin.type != kex_reply_value) { |
32874aea |
3546 | bombout(("expected key exchange reply packet from server")); |
3547 | crReturn(0); |
7cca0d81 |
3548 | } |
e5574168 |
3549 | ssh2_pkt_getstring(&hostkeydata, &hostkeylen); |
3550 | f = ssh2_pkt_getmp(); |
e5574168 |
3551 | ssh2_pkt_getstring(&sigdata, &siglen); |
3552 | |
3553 | K = dh_find_K(f); |
e5574168 |
3554 | |
3555 | sha_string(&exhash, hostkeydata, hostkeylen); |
a92dd380 |
3556 | if (kex == &ssh_diffiehellman_gex) { |
32874aea |
3557 | sha_uint32(&exhash, pbits); |
3558 | sha_mpint(&exhash, p); |
3559 | sha_mpint(&exhash, g); |
a92dd380 |
3560 | } |
e5574168 |
3561 | sha_mpint(&exhash, e); |
3562 | sha_mpint(&exhash, f); |
3563 | sha_mpint(&exhash, K); |
3564 | SHA_Final(&exhash, exchange_hash); |
3565 | |
3709bfe9 |
3566 | dh_cleanup(); |
3567 | |
7cca0d81 |
3568 | #if 0 |
765c4200 |
3569 | debug(("Exchange hash is:\n")); |
3570 | dmemdump(exchange_hash, 20); |
7cca0d81 |
3571 | #endif |
3572 | |
e055a386 |
3573 | hkey = hostkey->newkey(hostkeydata, hostkeylen); |
f7259d10 |
3574 | if (!hkey || |
3575 | !hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) { |
3576 | bombout(("Server's host key did not match the signature supplied")); |
32874aea |
3577 | crReturn(0); |
8d5de777 |
3578 | } |
e5574168 |
3579 | |
3580 | /* |
7cca0d81 |
3581 | * Authenticate remote host: verify host key. (We've already |
3582 | * checked the signature of the exchange hash.) |
e5574168 |
3583 | */ |
e055a386 |
3584 | keystr = hostkey->fmtkey(hkey); |
3585 | fingerprint = hostkey->fingerprint(hkey); |
d4857987 |
3586 | verify_ssh_host_key(savedhost, savedport, hostkey->keytype, |
32874aea |
3587 | keystr, fingerprint); |
3588 | if (first_kex) { /* don't bother logging this in rekeys */ |
5e0d7cb8 |
3589 | logevent("Host key fingerprint is:"); |
3590 | logevent(fingerprint); |
3591 | } |
dcbde236 |
3592 | sfree(fingerprint); |
3593 | sfree(keystr); |
e055a386 |
3594 | hostkey->freekey(hkey); |
d39f364a |
3595 | |
3596 | /* |
7cca0d81 |
3597 | * Send SSH2_MSG_NEWKEYS. |
d39f364a |
3598 | */ |
3599 | ssh2_pkt_init(SSH2_MSG_NEWKEYS); |
3600 | ssh2_pkt_send(); |
d39f364a |
3601 | |
3602 | /* |
8406eaf9 |
3603 | * Expect SSH2_MSG_NEWKEYS from server. |
3604 | */ |
3605 | crWaitUntil(ispkt); |
3606 | if (pktin.type != SSH2_MSG_NEWKEYS) { |
3607 | bombout(("expected new-keys packet from server")); |
3608 | crReturn(0); |
3609 | } |
3610 | |
3611 | /* |
d39f364a |
3612 | * Create and initialise session keys. |
3613 | */ |
3614 | cscipher = cscipher_tobe; |
3615 | sccipher = sccipher_tobe; |
3616 | csmac = csmac_tobe; |
3617 | scmac = scmac_tobe; |
3618 | cscomp = cscomp_tobe; |
3619 | sccomp = sccomp_tobe; |
4ba9b64b |
3620 | cscomp->compress_init(); |
3621 | sccomp->decompress_init(); |
d39f364a |
3622 | /* |
5e0d7cb8 |
3623 | * Set IVs after keys. Here we use the exchange hash from the |
3624 | * _first_ key exchange. |
d39f364a |
3625 | */ |
5e0d7cb8 |
3626 | if (first_kex) |
65a22376 |
3627 | memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash)); |
3628 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace); |
5e0d7cb8 |
3629 | cscipher->setcskey(keyspace); |
65a22376 |
3630 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace); |
5e0d7cb8 |
3631 | sccipher->setsckey(keyspace); |
65a22376 |
3632 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace); |
5e0d7cb8 |
3633 | cscipher->setcsiv(keyspace); |
65a22376 |
3634 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace); |
5e0d7cb8 |
3635 | sccipher->setsciv(keyspace); |
65a22376 |
3636 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace); |
5e0d7cb8 |
3637 | csmac->setcskey(keyspace); |
65a22376 |
3638 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace); |
5e0d7cb8 |
3639 | scmac->setsckey(keyspace); |
d39f364a |
3640 | |
033b4cef |
3641 | /* |
0db56f73 |
3642 | * If this is the first key exchange phase, we must pass the |
3643 | * SSH2_MSG_NEWKEYS packet to the next layer, not because it |
3644 | * wants to see it but because it will need time to initialise |
3645 | * itself before it sees an actual packet. In subsequent key |
3646 | * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because |
3647 | * it would only confuse the layer above. |
3648 | */ |
3649 | if (!first_kex) { |
32874aea |
3650 | crReturn(0); |
0db56f73 |
3651 | } |
3652 | first_kex = 0; |
3653 | |
3654 | /* |
7cca0d81 |
3655 | * Now we're encrypting. Begin returning 1 to the protocol main |
3656 | * function so that other things can run on top of the |
3657 | * transport. If we ever see a KEXINIT, we must go back to the |
3658 | * start. |
033b4cef |
3659 | */ |
e96adf72 |
3660 | while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) { |
32874aea |
3661 | crReturn(1); |
e96adf72 |
3662 | } |
5e0d7cb8 |
3663 | logevent("Server initiated key re-exchange"); |
7cca0d81 |
3664 | goto begin_key_exchange; |
e5574168 |
3665 | |
3666 | crFinish(1); |
3667 | } |
3668 | |
7cca0d81 |
3669 | /* |
783415f8 |
3670 | * Add data to an SSH2 channel output buffer. |
3671 | */ |
32874aea |
3672 | static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, |
3673 | int len) |
3674 | { |
5471d09a |
3675 | bufchain_add(&c->v.v2.outbuffer, buf, len); |
783415f8 |
3676 | } |
3677 | |
3678 | /* |
3679 | * Attempt to send data on an SSH2 channel. |
3680 | */ |
5471d09a |
3681 | static int ssh2_try_send(struct ssh_channel *c) |
32874aea |
3682 | { |
5471d09a |
3683 | while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) { |
3684 | int len; |
3685 | void *data; |
3686 | bufchain_prefix(&c->v.v2.outbuffer, &data, &len); |
3687 | if ((unsigned)len > c->v.v2.remwindow) |
3688 | len = c->v.v2.remwindow; |
3689 | if ((unsigned)len > c->v.v2.remmaxpkt) |
3690 | len = c->v.v2.remmaxpkt; |
32874aea |
3691 | ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA); |
3692 | ssh2_pkt_adduint32(c->remoteid); |
3693 | ssh2_pkt_addstring_start(); |
5471d09a |
3694 | ssh2_pkt_addstring_data(data, len); |
32874aea |
3695 | ssh2_pkt_send(); |
5471d09a |
3696 | bufchain_consume(&c->v.v2.outbuffer, len); |
3697 | c->v.v2.remwindow -= len; |
3698 | } |
3699 | |
3700 | /* |
3701 | * After having sent as much data as we can, return the amount |
3702 | * still buffered. |
3703 | */ |
3704 | return bufchain_size(&c->v.v2.outbuffer); |
3705 | } |
3706 | |
3707 | /* |
3708 | * Potentially enlarge the window on an SSH2 channel. |
3709 | */ |
3710 | static void ssh2_set_window(struct ssh_channel *c, unsigned newwin) |
3711 | { |
3712 | if (newwin > c->v.v2.locwindow) { |
3713 | ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
3714 | ssh2_pkt_adduint32(c->remoteid); |
3715 | ssh2_pkt_adduint32(newwin - c->v.v2.locwindow); |
3716 | ssh2_pkt_send(); |
3717 | c->v.v2.locwindow = newwin; |
783415f8 |
3718 | } |
3719 | } |
3720 | |
3721 | /* |
7cca0d81 |
3722 | * Handle the SSH2 userauth and connection layers. |
3723 | */ |
3724 | static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) |
3725 | { |
65a22376 |
3726 | static enum { |
32874aea |
3727 | AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE, |
761187b6 |
3728 | AUTH_PASSWORD, |
3729 | AUTH_KEYBOARD_INTERACTIVE |
65a22376 |
3730 | } method; |
1408a877 |
3731 | static enum { |
32874aea |
3732 | AUTH_TYPE_NONE, |
3733 | AUTH_TYPE_PUBLICKEY, |
3734 | AUTH_TYPE_PUBLICKEY_OFFER_LOUD, |
3735 | AUTH_TYPE_PUBLICKEY_OFFER_QUIET, |
761187b6 |
3736 | AUTH_TYPE_PASSWORD, |
4bdf7c46 |
3737 | AUTH_TYPE_KEYBOARD_INTERACTIVE, |
3738 | AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET |
1408a877 |
3739 | } type; |
761187b6 |
3740 | static int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter; |
3741 | static int tried_pubkey_config, tried_agent, tried_keyb_inter; |
b3186d64 |
3742 | static int kbd_inter_running; |
1408a877 |
3743 | static int we_are_in; |
761187b6 |
3744 | static int num_prompts, echo; |
65a22376 |
3745 | static char username[100]; |
3746 | static char pwprompt[200]; |
3747 | static char password[100]; |
7cca0d81 |
3748 | |
e5574168 |
3749 | crBegin; |
3750 | |
7cca0d81 |
3751 | /* |
3752 | * Request userauth protocol, and await a response to it. |
3753 | */ |
3754 | ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST); |
3755 | ssh2_pkt_addstring("ssh-userauth"); |
3756 | ssh2_pkt_send(); |
3757 | crWaitUntilV(ispkt); |
8d5de777 |
3758 | if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) { |
32874aea |
3759 | bombout(("Server refused user authentication protocol")); |
3760 | crReturnV; |
8d5de777 |
3761 | } |
7cca0d81 |
3762 | |
3763 | /* |
1408a877 |
3764 | * We repeat this whole loop, including the username prompt, |
3765 | * until we manage a successful authentication. If the user |
3766 | * types the wrong _password_, they are sent back to the |
3767 | * beginning to try another username. (If they specify a |
3768 | * username in the config, they are never asked, even if they |
3769 | * do give a wrong password.) |
3770 | * |
3771 | * I think this best serves the needs of |
3772 | * |
3773 | * - the people who have no configuration, no keys, and just |
3774 | * want to try repeated (username,password) pairs until they |
3775 | * type both correctly |
3776 | * |
3777 | * - people who have keys and configuration but occasionally |
3778 | * need to fall back to passwords |
3779 | * |
3780 | * - people with a key held in Pageant, who might not have |
3781 | * logged in to a particular machine before; so they want to |
3782 | * type a username, and then _either_ their key will be |
3783 | * accepted, _or_ they will type a password. If they mistype |
3784 | * the username they will want to be able to get back and |
3785 | * retype it! |
7cca0d81 |
3786 | */ |
5bb641e1 |
3787 | username[0] = '\0'; |
1408a877 |
3788 | do { |
3789 | static int pos; |
7cca0d81 |
3790 | static char c; |
e5574168 |
3791 | |
1408a877 |
3792 | /* |
3793 | * Get a username. |
3794 | */ |
3795 | pos = 0; |
5bb641e1 |
3796 | if (*username && !cfg.change_username) { |
3797 | /* |
3798 | * We got a username last time round this loop, and |
3799 | * with change_username turned off we don't try to get |
3800 | * it again. |
3801 | */ |
3802 | } else if ((flags & FLAG_INTERACTIVE) && !*cfg.username) { |
32874aea |
3803 | if (ssh_get_line) { |
3804 | if (!ssh_get_line("login as: ", |
3805 | username, sizeof(username), FALSE)) { |
3806 | /* |
3807 | * get_line failed to get a username. |
3808 | * Terminate. |
3809 | */ |
3810 | logevent("No username provided. Abandoning session."); |
3811 | ssh_state = SSH_STATE_CLOSED; |
3812 | crReturnV; |
3813 | } |
3814 | } else { |
3815 | c_write_str("login as: "); |
3816 | ssh_send_ok = 1; |
3817 | while (pos >= 0) { |
3818 | crWaitUntilV(!ispkt); |
3819 | while (inlen--) |
3820 | switch (c = *in++) { |
3821 | case 10: |
3822 | case 13: |
3823 | username[pos] = 0; |
3824 | pos = -1; |
3825 | break; |
3826 | case 8: |
3827 | case 127: |
3828 | if (pos > 0) { |
3829 | c_write_str("\b \b"); |
3830 | pos--; |
3831 | } |
3832 | break; |
3833 | case 21: |
3834 | case 27: |
3835 | while (pos > 0) { |
3836 | c_write_str("\b \b"); |
3837 | pos--; |
3838 | } |
3839 | break; |
3840 | case 3: |
3841 | case 4: |
3842 | random_save_seed(); |
3843 | exit(0); |
3844 | break; |
3845 | default: |
3846 | if (((c >= ' ' && c <= '~') || |
51b2fb65 |
3847 | ((unsigned char) c >= 160)) |
3848 | && pos < sizeof(username)-1) { |
32874aea |
3849 | username[pos++] = c; |
3850 | c_write(&c, 1); |
3851 | } |
3852 | break; |
3853 | } |
3854 | } |
3855 | } |
1408a877 |
3856 | c_write_str("\r\n"); |
7cca0d81 |
3857 | username[strcspn(username, "\n\r")] = '\0'; |
3858 | } else { |
3859 | char stuff[200]; |
3860 | strncpy(username, cfg.username, 99); |
3861 | username[99] = '\0'; |
65a22376 |
3862 | if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) { |
7cca0d81 |
3863 | sprintf(stuff, "Using username \"%s\".\r\n", username); |
1408a877 |
3864 | c_write_str(stuff); |
7cca0d81 |
3865 | } |
3866 | } |
3867 | |
65a22376 |
3868 | /* |
1408a877 |
3869 | * Send an authentication request using method "none": (a) |
3870 | * just in case it succeeds, and (b) so that we know what |
3871 | * authentication methods we can usefully try next. |
65a22376 |
3872 | */ |
00db133f |
3873 | ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; |
3874 | |
1408a877 |
3875 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
3876 | ssh2_pkt_addstring(username); |
32874aea |
3877 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
1408a877 |
3878 | ssh2_pkt_addstring("none"); /* method */ |
3879 | ssh2_pkt_send(); |
3880 | type = AUTH_TYPE_NONE; |
3881 | gotit = FALSE; |
3882 | we_are_in = FALSE; |
7cca0d81 |
3883 | |
1408a877 |
3884 | tried_pubkey_config = FALSE; |
1983e559 |
3885 | tried_agent = FALSE; |
b3186d64 |
3886 | tried_keyb_inter = FALSE; |
3887 | kbd_inter_running = FALSE; |
65a22376 |
3888 | |
1408a877 |
3889 | while (1) { |
3890 | /* |
3891 | * Wait for the result of the last authentication request. |
3892 | */ |
3893 | if (!gotit) |
3894 | crWaitUntilV(ispkt); |
3895 | while (pktin.type == SSH2_MSG_USERAUTH_BANNER) { |
32874aea |
3896 | char *banner; |
3897 | int size; |
3898 | /* |
3899 | * Don't show the banner if we're operating in |
3900 | * non-verbose non-interactive mode. (It's probably |
3901 | * a script, which means nobody will read the |
3902 | * banner _anyway_, and moreover the printing of |
3903 | * the banner will screw up processing on the |
3904 | * output of (say) plink.) |
3905 | */ |
3906 | if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) { |
3907 | ssh2_pkt_getstring(&banner, &size); |
3908 | if (banner) |
3909 | c_write_untrusted(banner, size); |
3910 | } |
1408a877 |
3911 | crWaitUntilV(ispkt); |
3912 | } |
3913 | if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) { |
3914 | logevent("Access granted"); |
3915 | we_are_in = TRUE; |
3916 | break; |
3917 | } |
65a22376 |
3918 | |
b3186d64 |
3919 | if (kbd_inter_running && |
3920 | pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) { |
3921 | /* |
3922 | * This is a further prompt in keyboard-interactive |
3923 | * authentication. Do nothing. |
3924 | */ |
6bb26b30 |
3925 | } else if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) { |
b3186d64 |
3926 | bombout(("Strange packet received during authentication: type %d", |
1408a877 |
3927 | pktin.type)); |
38c4a8da |
3928 | crReturnV; |
65a22376 |
3929 | } |
3930 | |
1408a877 |
3931 | gotit = FALSE; |
65a22376 |
3932 | |
1408a877 |
3933 | /* |
3934 | * OK, we're now sitting on a USERAUTH_FAILURE message, so |
3935 | * we can look at the string in it and know what we can |
3936 | * helpfully try next. |
3937 | */ |
b3186d64 |
3938 | if (pktin.type == SSH2_MSG_USERAUTH_FAILURE) { |
1408a877 |
3939 | char *methods; |
3940 | int methlen; |
3941 | ssh2_pkt_getstring(&methods, &methlen); |
b3186d64 |
3942 | kbd_inter_running = FALSE; |
1408a877 |
3943 | if (!ssh2_pkt_getbool()) { |
3944 | /* |
3945 | * We have received an unequivocal Access |
3946 | * Denied. This can translate to a variety of |
3947 | * messages: |
3948 | * |
3949 | * - if we'd just tried "none" authentication, |
3950 | * it's not worth printing anything at all |
3951 | * |
3952 | * - if we'd just tried a public key _offer_, |
3953 | * the message should be "Server refused our |
3954 | * key" (or no message at all if the key |
3955 | * came from Pageant) |
3956 | * |
3957 | * - if we'd just tried anything else, the |
3958 | * message really should be "Access denied". |
3959 | * |
3960 | * Additionally, if we'd just tried password |
3961 | * authentication, we should break out of this |
3962 | * whole loop so as to go back to the username |
3963 | * prompt. |
3964 | */ |
3965 | if (type == AUTH_TYPE_NONE) { |
3966 | /* do nothing */ |
3967 | } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD || |
3968 | type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) { |
3969 | if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD) |
3970 | c_write_str("Server refused our key\r\n"); |
3971 | logevent("Server refused public key"); |
4bdf7c46 |
3972 | } else if (type == AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) { |
3973 | /* server declined keyboard-interactive; ignore */ |
1408a877 |
3974 | } else { |
3975 | c_write_str("Access denied\r\n"); |
3976 | logevent("Access denied"); |
3977 | if (type == AUTH_TYPE_PASSWORD) { |
3978 | we_are_in = FALSE; |
3979 | break; |
3980 | } |
3981 | } |
3982 | } else { |
3983 | c_write_str("Further authentication required\r\n"); |
3984 | logevent("Further authentication required"); |
3985 | } |
65a22376 |
3986 | |
32874aea |
3987 | can_pubkey = |
3988 | in_commasep_string("publickey", methods, methlen); |
3989 | can_passwd = |
3990 | in_commasep_string("password", methods, methlen); |
f091e308 |
3991 | can_keyb_inter = cfg.try_ki_auth && |
761187b6 |
3992 | in_commasep_string("keyboard-interactive", methods, methlen); |
1408a877 |
3993 | } |
65a22376 |
3994 | |
1408a877 |
3995 | method = 0; |
00db133f |
3996 | ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; |
65a22376 |
3997 | |
78afa559 |
3998 | if (!method && can_pubkey && agent_exists() && !tried_agent) { |
1983e559 |
3999 | /* |
4000 | * Attempt public-key authentication using Pageant. |
4001 | */ |
4002 | static unsigned char request[5], *response, *p; |
4003 | static int responselen; |
4004 | static int i, nkeys; |
4005 | static int authed = FALSE; |
4006 | void *r; |
4007 | |
00db133f |
4008 | ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY; |
4009 | |
1983e559 |
4010 | tried_agent = TRUE; |
4011 | |
4012 | logevent("Pageant is running. Requesting keys."); |
4013 | |
4014 | /* Request the keys held by the agent. */ |
4015 | PUT_32BIT(request, 1); |
4016 | request[4] = SSH2_AGENTC_REQUEST_IDENTITIES; |
4017 | agent_query(request, 5, &r, &responselen); |
32874aea |
4018 | response = (unsigned char *) r; |
95797139 |
4019 | if (response && responselen >= 5 && |
32874aea |
4020 | response[4] == SSH2_AGENT_IDENTITIES_ANSWER) { |
1983e559 |
4021 | p = response + 5; |
32874aea |
4022 | nkeys = GET_32BIT(p); |
4023 | p += 4; |
4024 | { |
4025 | char buf[64]; |
4026 | sprintf(buf, "Pageant has %d SSH2 keys", nkeys); |
4027 | logevent(buf); |
4028 | } |
1983e559 |
4029 | for (i = 0; i < nkeys; i++) { |
4030 | static char *pkblob, *alg, *commentp; |
4031 | static int pklen, alglen, commentlen; |
4032 | static int siglen, retlen, len; |
4033 | static char *q, *agentreq, *ret; |
2d466ffd |
4034 | void *vret; |
1983e559 |
4035 | |
32874aea |
4036 | { |
4037 | char buf[64]; |
4038 | sprintf(buf, "Trying Pageant key #%d", i); |
4039 | logevent(buf); |
4040 | } |
4041 | pklen = GET_32BIT(p); |
4042 | p += 4; |
4043 | pkblob = p; |
4044 | p += pklen; |
1983e559 |
4045 | alglen = GET_32BIT(pkblob); |
4046 | alg = pkblob + 4; |
32874aea |
4047 | commentlen = GET_32BIT(p); |
4048 | p += 4; |
4049 | commentp = p; |
4050 | p += commentlen; |
1983e559 |
4051 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
4052 | ssh2_pkt_addstring(username); |
32874aea |
4053 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
4054 | ssh2_pkt_addstring("publickey"); /* method */ |
4055 | ssh2_pkt_addbool(FALSE); /* no signature included */ |
1983e559 |
4056 | ssh2_pkt_addstring_start(); |
4057 | ssh2_pkt_addstring_data(alg, alglen); |
4058 | ssh2_pkt_addstring_start(); |
4059 | ssh2_pkt_addstring_data(pkblob, pklen); |
4060 | ssh2_pkt_send(); |
4061 | |
4062 | crWaitUntilV(ispkt); |
4063 | if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) { |
4064 | logevent("Key refused"); |
4065 | continue; |
4066 | } |
4067 | |
32874aea |
4068 | if (flags & FLAG_VERBOSE) { |
4069 | c_write_str |
4070 | ("Authenticating with public key \""); |
4071 | c_write(commentp, commentlen); |
4072 | c_write_str("\" from agent\r\n"); |
4073 | } |
1983e559 |
4074 | |
4075 | /* |
4076 | * Server is willing to accept the key. |
4077 | * Construct a SIGN_REQUEST. |
4078 | */ |
4079 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
4080 | ssh2_pkt_addstring(username); |
32874aea |
4081 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
4082 | ssh2_pkt_addstring("publickey"); /* method */ |
1983e559 |
4083 | ssh2_pkt_addbool(TRUE); |
4084 | ssh2_pkt_addstring_start(); |
4085 | ssh2_pkt_addstring_data(alg, alglen); |
4086 | ssh2_pkt_addstring_start(); |
4087 | ssh2_pkt_addstring_data(pkblob, pklen); |
4088 | |
4089 | siglen = pktout.length - 5 + 4 + 20; |
32874aea |
4090 | len = 1; /* message type */ |
4091 | len += 4 + pklen; /* key blob */ |
4092 | len += 4 + siglen; /* data to sign */ |
4093 | len += 4; /* flags */ |
1983e559 |
4094 | agentreq = smalloc(4 + len); |
4095 | PUT_32BIT(agentreq, len); |
4096 | q = agentreq + 4; |
4097 | *q++ = SSH2_AGENTC_SIGN_REQUEST; |
32874aea |
4098 | PUT_32BIT(q, pklen); |
4099 | q += 4; |
4100 | memcpy(q, pkblob, pklen); |
4101 | q += pklen; |
4102 | PUT_32BIT(q, siglen); |
4103 | q += 4; |
1983e559 |
4104 | /* Now the data to be signed... */ |
32874aea |
4105 | PUT_32BIT(q, 20); |
4106 | q += 4; |
4107 | memcpy(q, ssh2_session_id, 20); |
4108 | q += 20; |
4109 | memcpy(q, pktout.data + 5, pktout.length - 5); |
4110 | q += pktout.length - 5; |
1983e559 |
4111 | /* And finally the (zero) flags word. */ |
4112 | PUT_32BIT(q, 0); |
2d466ffd |
4113 | agent_query(agentreq, len + 4, &vret, &retlen); |
4114 | ret = vret; |
1983e559 |
4115 | sfree(agentreq); |
4116 | if (ret) { |
4117 | if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) { |
4118 | logevent("Sending Pageant's response"); |
4119 | ssh2_pkt_addstring_start(); |
32874aea |
4120 | ssh2_pkt_addstring_data(ret + 9, |
4121 | GET_32BIT(ret + |
4122 | 5)); |
1983e559 |
4123 | ssh2_pkt_send(); |
4124 | authed = TRUE; |
4125 | break; |
4126 | } else { |
32874aea |
4127 | logevent |
4128 | ("Pageant failed to answer challenge"); |
1983e559 |
4129 | sfree(ret); |
4130 | } |
4131 | } |
4132 | } |
4133 | if (authed) |
4134 | continue; |
4135 | } |
4136 | } |
4137 | |
32874aea |
4138 | if (!method && can_pubkey && *cfg.keyfile |
4139 | && !tried_pubkey_config) { |
1408a877 |
4140 | unsigned char *pub_blob; |
4141 | char *algorithm, *comment; |
4142 | int pub_blob_len; |
65a22376 |
4143 | |
1408a877 |
4144 | tried_pubkey_config = TRUE; |
65a22376 |
4145 | |
00db133f |
4146 | ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY; |
4147 | |
65a22376 |
4148 | /* |
1408a877 |
4149 | * Try the public key supplied in the configuration. |
4150 | * |
4151 | * First, offer the public blob to see if the server is |
4152 | * willing to accept it. |
65a22376 |
4153 | */ |
1408a877 |
4154 | pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm, |
4155 | &pub_blob_len); |
4156 | if (pub_blob) { |
4157 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
4158 | ssh2_pkt_addstring(username); |
32874aea |
4159 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
4160 | ssh2_pkt_addstring("publickey"); /* method */ |
4161 | ssh2_pkt_addbool(FALSE); /* no signature included */ |
1408a877 |
4162 | ssh2_pkt_addstring(algorithm); |
4163 | ssh2_pkt_addstring_start(); |
4164 | ssh2_pkt_addstring_data(pub_blob, pub_blob_len); |
4165 | ssh2_pkt_send(); |
32874aea |
4166 | logevent("Offered public key"); /* FIXME */ |
1408a877 |
4167 | |
4168 | crWaitUntilV(ispkt); |
4169 | if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) { |
4170 | gotit = TRUE; |
4171 | type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD; |
32874aea |
4172 | continue; /* key refused; give up on it */ |
1408a877 |
4173 | } |
65a22376 |
4174 | |
1408a877 |
4175 | logevent("Offer of public key accepted"); |
65a22376 |
4176 | /* |
1408a877 |
4177 | * Actually attempt a serious authentication using |
4178 | * the key. |
65a22376 |
4179 | */ |
1408a877 |
4180 | if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) { |
32874aea |
4181 | sprintf(pwprompt, |
4182 | "Passphrase for key \"%.100s\": ", |
4183 | comment); |
1408a877 |
4184 | need_pw = TRUE; |
4185 | } else { |
4186 | need_pw = FALSE; |
4187 | } |
4188 | c_write_str("Authenticating with public key \""); |
4189 | c_write_str(comment); |
4190 | c_write_str("\"\r\n"); |
4191 | method = AUTH_PUBLICKEY_FILE; |
65a22376 |
4192 | } |
1408a877 |
4193 | } |
4194 | |
af659722 |
4195 | if (!method && can_keyb_inter && !tried_keyb_inter) { |
4196 | method = AUTH_KEYBOARD_INTERACTIVE; |
4197 | type = AUTH_TYPE_KEYBOARD_INTERACTIVE; |
4198 | tried_keyb_inter = TRUE; |
4199 | |
00db133f |
4200 | ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER; |
4201 | |
af659722 |
4202 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
4203 | ssh2_pkt_addstring(username); |
4204 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
4205 | ssh2_pkt_addstring("keyboard-interactive"); /* method */ |
4206 | ssh2_pkt_addstring(""); /* lang */ |
4207 | ssh2_pkt_addstring(""); |
4208 | ssh2_pkt_send(); |
4209 | |
4210 | crWaitUntilV(ispkt); |
4211 | if (pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) { |
4212 | if (pktin.type == SSH2_MSG_USERAUTH_FAILURE) |
4213 | gotit = TRUE; |
4214 | logevent("Keyboard-interactive authentication refused"); |
4215 | type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET; |
4216 | continue; |
4217 | } |
4218 | |
4219 | kbd_inter_running = TRUE; |
4220 | } |
4221 | |
4222 | if (kbd_inter_running) { |
4223 | method = AUTH_KEYBOARD_INTERACTIVE; |
4224 | type = AUTH_TYPE_KEYBOARD_INTERACTIVE; |
4225 | tried_keyb_inter = TRUE; |
4226 | |
00db133f |
4227 | ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER; |
4228 | |
af659722 |
4229 | /* We've got packet with that "interactive" info |
4230 | dump banners, and set its prompt as ours */ |
4231 | { |
4232 | char *name, *inst, *lang, *prompt; |
4233 | int name_len, inst_len, lang_len, prompt_len; |
4234 | ssh2_pkt_getstring(&name, &name_len); |
4235 | ssh2_pkt_getstring(&inst, &inst_len); |
4236 | ssh2_pkt_getstring(&lang, &lang_len); |
4237 | if (name_len > 0) |
4238 | c_write_untrusted(name, name_len); |
4239 | if (inst_len > 0) |
4240 | c_write_untrusted(inst, inst_len); |
4241 | num_prompts = ssh2_pkt_getuint32(); |
4242 | |
4243 | ssh2_pkt_getstring(&prompt, &prompt_len); |
4244 | strncpy(pwprompt, prompt, sizeof(pwprompt)); |
2c2f4dba |
4245 | pwprompt[prompt_len < sizeof(pwprompt) ? |
4246 | prompt_len : sizeof(pwprompt)-1] = '\0'; |
af659722 |
4247 | need_pw = TRUE; |
4248 | |
4249 | echo = ssh2_pkt_getbool(); |
4250 | } |
4251 | } |
4252 | |
1408a877 |
4253 | if (!method && can_passwd) { |
4254 | method = AUTH_PASSWORD; |
00db133f |
4255 | ssh_pkt_ctx |= SSH2_PKTCTX_PASSWORD; |
32874aea |
4256 | sprintf(pwprompt, "%.90s@%.90s's password: ", username, |
4257 | savedhost); |
1408a877 |
4258 | need_pw = TRUE; |
4259 | } |
4260 | |
4261 | if (need_pw) { |
fa17a66e |
4262 | if (ssh_get_line) { |
4263 | if (!ssh_get_line(pwprompt, password, |
32874aea |
4264 | sizeof(password), TRUE)) { |
1408a877 |
4265 | /* |
fa17a66e |
4266 | * get_line failed to get a password (for |
4267 | * example because one was supplied on the |
4268 | * command line which has already failed to |
4269 | * work). Terminate. |
1408a877 |
4270 | */ |
2bc6a386 |
4271 | ssh2_pkt_init(SSH2_MSG_DISCONNECT); |
4272 | ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION); |
4273 | ssh2_pkt_addstring |
4274 | ("No more passwords available to try"); |
4275 | ssh2_pkt_addstring("en"); /* language tag */ |
4276 | ssh2_pkt_send(); |
4277 | connection_fatal("Unable to authenticate"); |
1408a877 |
4278 | ssh_state = SSH_STATE_CLOSED; |
4279 | crReturnV; |
4280 | } |
4281 | } else { |
4282 | static int pos = 0; |
4283 | static char c; |
4284 | |
761187b6 |
4285 | c_write_untrusted(pwprompt, strlen(pwprompt)); |
1408a877 |
4286 | ssh_send_ok = 1; |
4287 | |
4288 | pos = 0; |
4289 | while (pos >= 0) { |
4290 | crWaitUntilV(!ispkt); |
32874aea |
4291 | while (inlen--) |
4292 | switch (c = *in++) { |
4293 | case 10: |
4294 | case 13: |
4295 | password[pos] = 0; |
4296 | pos = -1; |
4297 | break; |
4298 | case 8: |
4299 | case 127: |
4300 | if (pos > 0) |
4301 | pos--; |
4302 | break; |
4303 | case 21: |
4304 | case 27: |
4305 | pos = 0; |
4306 | break; |
4307 | case 3: |
4308 | case 4: |
4309 | random_save_seed(); |
4310 | exit(0); |
4311 | break; |
4312 | default: |
51b2fb65 |
4313 | if (pos < sizeof(password)-1) |
32874aea |
4314 | password[pos++] = c; |
4315 | break; |
4316 | } |
65a22376 |
4317 | } |
1408a877 |
4318 | c_write_str("\r\n"); |
65a22376 |
4319 | } |
65a22376 |
4320 | } |
65a22376 |
4321 | |
1408a877 |
4322 | if (method == AUTH_PUBLICKEY_FILE) { |
4323 | /* |
4324 | * We have our passphrase. Now try the actual authentication. |
4325 | */ |
4326 | struct ssh2_userkey *key; |
65a22376 |
4327 | |
1408a877 |
4328 | key = ssh2_load_userkey(cfg.keyfile, password); |
4329 | if (key == SSH2_WRONG_PASSPHRASE || key == NULL) { |
4330 | if (key == SSH2_WRONG_PASSPHRASE) { |
4331 | c_write_str("Wrong passphrase\r\n"); |
4332 | tried_pubkey_config = FALSE; |
4333 | } else { |
4334 | c_write_str("Unable to load private key\r\n"); |
4335 | tried_pubkey_config = TRUE; |
4336 | } |
4337 | /* Send a spurious AUTH_NONE to return to the top. */ |
4338 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
4339 | ssh2_pkt_addstring(username); |
32874aea |
4340 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
4341 | ssh2_pkt_addstring("none"); /* method */ |
1408a877 |
4342 | ssh2_pkt_send(); |
4343 | type = AUTH_TYPE_NONE; |
4344 | } else { |
4345 | unsigned char *blob, *sigdata; |
4346 | int blob_len, sigdata_len; |
65a22376 |
4347 | |
1408a877 |
4348 | /* |
4349 | * We have loaded the private key and the server |
4350 | * has announced that it's willing to accept it. |
4351 | * Hallelujah. Generate a signature and send it. |
4352 | */ |
4353 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
4354 | ssh2_pkt_addstring(username); |
32874aea |
4355 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
4356 | ssh2_pkt_addstring("publickey"); /* method */ |
1408a877 |
4357 | ssh2_pkt_addbool(TRUE); |
4358 | ssh2_pkt_addstring(key->alg->name); |
4359 | blob = key->alg->public_blob(key->data, &blob_len); |
4360 | ssh2_pkt_addstring_start(); |
4361 | ssh2_pkt_addstring_data(blob, blob_len); |
4362 | sfree(blob); |
4363 | |
4364 | /* |
4365 | * The data to be signed is: |
4366 | * |
4367 | * string session-id |
4368 | * |
4369 | * followed by everything so far placed in the |
4370 | * outgoing packet. |
4371 | */ |
4372 | sigdata_len = pktout.length - 5 + 4 + 20; |
4373 | sigdata = smalloc(sigdata_len); |
4374 | PUT_32BIT(sigdata, 20); |
32874aea |
4375 | memcpy(sigdata + 4, ssh2_session_id, 20); |
4376 | memcpy(sigdata + 24, pktout.data + 5, |
4377 | pktout.length - 5); |
4378 | blob = |
4379 | key->alg->sign(key->data, sigdata, sigdata_len, |
4380 | &blob_len); |
1408a877 |
4381 | ssh2_pkt_addstring_start(); |
4382 | ssh2_pkt_addstring_data(blob, blob_len); |
4383 | sfree(blob); |
4384 | sfree(sigdata); |
4385 | |
4386 | ssh2_pkt_send(); |
4387 | type = AUTH_TYPE_PUBLICKEY; |
4388 | } |
4389 | } else if (method == AUTH_PASSWORD) { |
65a22376 |
4390 | /* |
1408a877 |
4391 | * We send the password packet lumped tightly together with |
4392 | * an SSH_MSG_IGNORE packet. The IGNORE packet contains a |
4393 | * string long enough to make the total length of the two |
4394 | * packets constant. This should ensure that a passive |
4395 | * listener doing traffic analyis can't work out the length |
4396 | * of the password. |
4397 | * |
4398 | * For this to work, we need an assumption about the |
4399 | * maximum length of the password packet. I think 256 is |
4400 | * pretty conservative. Anyone using a password longer than |
4401 | * that probably doesn't have much to worry about from |
4402 | * people who find out how long their password is! |
65a22376 |
4403 | */ |
4404 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
4405 | ssh2_pkt_addstring(username); |
32874aea |
4406 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
1408a877 |
4407 | ssh2_pkt_addstring("password"); |
4408 | ssh2_pkt_addbool(FALSE); |
4409 | ssh2_pkt_addstring(password); |
4410 | ssh2_pkt_defer(); |
65a22376 |
4411 | /* |
1408a877 |
4412 | * We'll include a string that's an exact multiple of the |
4413 | * cipher block size. If the cipher is NULL for some |
4414 | * reason, we don't do this trick at all because we gain |
4415 | * nothing by it. |
65a22376 |
4416 | */ |
32874aea |
4417 | if (cscipher) { |
4418 | int stringlen, i; |
4419 | |
4420 | stringlen = (256 - deferred_len); |
4421 | stringlen += cscipher->blksize - 1; |
4422 | stringlen -= (stringlen % cscipher->blksize); |
4423 | if (cscomp) { |
4424 | /* |
4425 | * Temporarily disable actual compression, |
4426 | * so we can guarantee to get this string |
4427 | * exactly the length we want it. The |
4428 | * compression-disabling routine should |
4429 | * return an integer indicating how many |
4430 | * bytes we should adjust our string length |
4431 | * by. |
4432 | */ |
4433 | stringlen -= cscomp->disable_compression(); |
4434 | } |
1408a877 |
4435 | ssh2_pkt_init(SSH2_MSG_IGNORE); |
4436 | ssh2_pkt_addstring_start(); |
6e9e9520 |
4437 | for (i = 0; i < stringlen; i++) { |
32874aea |
4438 | char c = (char) random_byte(); |
4439 | ssh2_pkt_addstring_data(&c, 1); |
65a22376 |
4440 | } |
1408a877 |
4441 | ssh2_pkt_defer(); |
65a22376 |
4442 | } |
39065bed |
4443 | ssh_pkt_defersend(); |
0d43337a |
4444 | logevent("Sent password"); |
1408a877 |
4445 | type = AUTH_TYPE_PASSWORD; |
761187b6 |
4446 | } else if (method == AUTH_KEYBOARD_INTERACTIVE) { |
4447 | ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE); |
4448 | ssh2_pkt_adduint32(num_prompts); |
4449 | ssh2_pkt_addstring(password); |
4450 | memset(password, 0, sizeof(password)); |
4451 | ssh2_pkt_send(); |
4452 | type = AUTH_TYPE_KEYBOARD_INTERACTIVE; |
1408a877 |
4453 | } else { |
32874aea |
4454 | c_write_str |
4455 | ("No supported authentication methods left to try!\r\n"); |
4456 | logevent |
4457 | ("No supported authentications offered. Disconnecting"); |
1408a877 |
4458 | ssh2_pkt_init(SSH2_MSG_DISCONNECT); |
4459 | ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION); |
32874aea |
4460 | ssh2_pkt_addstring |
4461 | ("No supported authentication methods available"); |
4462 | ssh2_pkt_addstring("en"); /* language tag */ |
1408a877 |
4463 | ssh2_pkt_send(); |
4464 | ssh_state = SSH_STATE_CLOSED; |
4465 | crReturnV; |
65a22376 |
4466 | } |
65a22376 |
4467 | } |
1408a877 |
4468 | } while (!we_are_in); |
7cca0d81 |
4469 | |
4470 | /* |
4471 | * Now we're authenticated for the connection protocol. The |
4472 | * connection protocol will automatically have started at this |
4473 | * point; there's no need to send SERVICE_REQUEST. |
4474 | */ |
4475 | |
4476 | /* |
4477 | * So now create a channel with a session in it. |
4478 | */ |
d2371c81 |
4479 | ssh_channels = newtree234(ssh_channelcmp); |
dcbde236 |
4480 | mainchan = smalloc(sizeof(struct ssh_channel)); |
d2371c81 |
4481 | mainchan->localid = alloc_channel_id(); |
7cca0d81 |
4482 | ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN); |
4483 | ssh2_pkt_addstring("session"); |
d211621f |
4484 | ssh2_pkt_adduint32(mainchan->localid); |
5471d09a |
4485 | mainchan->v.v2.locwindow = OUR_V2_WINSIZE; |
4486 | ssh2_pkt_adduint32(mainchan->v.v2.locwindow); /* our window size */ |
32874aea |
4487 | ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */ |
7cca0d81 |
4488 | ssh2_pkt_send(); |
4489 | crWaitUntilV(ispkt); |
4490 | if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) { |
32874aea |
4491 | bombout(("Server refused to open a session")); |
4492 | crReturnV; |
4493 | /* FIXME: error data comes back in FAILURE packet */ |
7cca0d81 |
4494 | } |
d211621f |
4495 | if (ssh2_pkt_getuint32() != mainchan->localid) { |
32874aea |
4496 | bombout(("Server's channel confirmation cited wrong channel")); |
4497 | crReturnV; |
7cca0d81 |
4498 | } |
d211621f |
4499 | mainchan->remoteid = ssh2_pkt_getuint32(); |
783415f8 |
4500 | mainchan->type = CHAN_MAINSESSION; |
4501 | mainchan->closes = 0; |
5471d09a |
4502 | mainchan->v.v2.remwindow = ssh2_pkt_getuint32(); |
4503 | mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32(); |
4504 | bufchain_init(&mainchan->v.v2.outbuffer); |
783415f8 |
4505 | add234(ssh_channels, mainchan); |
7cca0d81 |
4506 | logevent("Opened channel for session"); |
4507 | |
4508 | /* |
783415f8 |
4509 | * Potentially enable X11 forwarding. |
4510 | */ |
4511 | if (cfg.x11_forward) { |
32874aea |
4512 | char proto[20], data[64]; |
4513 | logevent("Requesting X11 forwarding"); |
4514 | x11_invent_auth(proto, sizeof(proto), data, sizeof(data)); |
4515 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
4516 | ssh2_pkt_adduint32(mainchan->remoteid); |
4517 | ssh2_pkt_addstring("x11-req"); |
4518 | ssh2_pkt_addbool(1); /* want reply */ |
4519 | ssh2_pkt_addbool(0); /* many connections */ |
4520 | ssh2_pkt_addstring(proto); |
4521 | ssh2_pkt_addstring(data); |
4522 | ssh2_pkt_adduint32(0); /* screen number */ |
4523 | ssh2_pkt_send(); |
4524 | |
4525 | do { |
4526 | crWaitUntilV(ispkt); |
4527 | if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
4528 | unsigned i = ssh2_pkt_getuint32(); |
4529 | struct ssh_channel *c; |
4530 | c = find234(ssh_channels, &i, ssh_channelfind); |
4531 | if (!c) |
4532 | continue; /* nonexistent channel */ |
5471d09a |
4533 | c->v.v2.remwindow += ssh2_pkt_getuint32(); |
32874aea |
4534 | } |
4535 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
4536 | |
4537 | if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
4538 | if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
c9886e66 |
4539 | bombout(("Unexpected response to X11 forwarding request:" |
4540 | " packet type %d", pktin.type)); |
32874aea |
4541 | crReturnV; |
4542 | } |
4543 | logevent("X11 forwarding refused"); |
4544 | } else { |
4545 | logevent("X11 forwarding enabled"); |
783415f8 |
4546 | ssh_X11_fwd_enabled = TRUE; |
32874aea |
4547 | } |
783415f8 |
4548 | } |
4549 | |
4550 | /* |
bc240b21 |
4551 | * Enable port forwardings. |
4552 | */ |
4553 | { |
4554 | static char *e; /* preserve across crReturn */ |
4555 | char type; |
4556 | int n; |
4557 | int sport,dport; |
4558 | char sports[256], dports[256], host[256]; |
4559 | char buf[1024]; |
4560 | |
4561 | ssh_rportfwds = newtree234(ssh_rportcmp_ssh2); |
4562 | /* Add port forwardings. */ |
4563 | e = cfg.portfwd; |
4564 | while (*e) { |
4565 | type = *e++; |
4566 | n = 0; |
4567 | while (*e && *e != '\t') |
4568 | sports[n++] = *e++; |
4569 | sports[n] = 0; |
4570 | if (*e == '\t') |
4571 | e++; |
4572 | n = 0; |
4573 | while (*e && *e != ':') |
4574 | host[n++] = *e++; |
4575 | host[n] = 0; |
4576 | if (*e == ':') |
4577 | e++; |
4578 | n = 0; |
4579 | while (*e) |
4580 | dports[n++] = *e++; |
4581 | dports[n] = 0; |
4582 | e++; |
4583 | dport = atoi(dports); |
4584 | sport = atoi(sports); |
4585 | if (sport && dport) { |
4586 | if (type == 'L') { |
4587 | pfd_addforward(host, dport, sport); |
4588 | sprintf(buf, "Local port %d forwarding to %s:%d", |
4589 | sport, host, dport); |
4590 | logevent(buf); |
4591 | } else { |
4592 | struct ssh_rportfwd *pf; |
4593 | pf = smalloc(sizeof(*pf)); |
4594 | strcpy(pf->dhost, host); |
4595 | pf->dport = dport; |
4596 | pf->sport = sport; |
4597 | if (add234(ssh_rportfwds, pf) != pf) { |
4598 | sprintf(buf, |
95bc8819 |
4599 | "Duplicate remote port forwarding to %s:%d", |
bc240b21 |
4600 | host, dport); |
4601 | logevent(buf); |
4602 | sfree(pf); |
4603 | } else { |
4604 | sprintf(buf, "Requesting remote port %d (forwarded to %s:%d)", |
4605 | sport, host, dport); |
4606 | logevent(buf); |
4607 | ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST); |
4608 | ssh2_pkt_addstring("tcpip-forward"); |
4609 | ssh2_pkt_addbool(1);/* want reply */ |
beefa433 |
4610 | if (cfg.rport_acceptall) |
4611 | ssh2_pkt_addstring("0.0.0.0"); |
4612 | else |
4613 | ssh2_pkt_addstring("127.0.0.1"); |
bc240b21 |
4614 | ssh2_pkt_adduint32(sport); |
4615 | ssh2_pkt_send(); |
4616 | |
4617 | do { |
4618 | crWaitUntilV(ispkt); |
4619 | if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
4620 | unsigned i = ssh2_pkt_getuint32(); |
4621 | struct ssh_channel *c; |
4622 | c = find234(ssh_channels, &i, ssh_channelfind); |
4623 | if (!c) |
4624 | continue;/* nonexistent channel */ |
5471d09a |
4625 | c->v.v2.remwindow += ssh2_pkt_getuint32(); |
bc240b21 |
4626 | } |
4627 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
4628 | |
4629 | if (pktin.type != SSH2_MSG_REQUEST_SUCCESS) { |
4630 | if (pktin.type != SSH2_MSG_REQUEST_FAILURE) { |
c9886e66 |
4631 | bombout(("Unexpected response to port " |
4632 | "forwarding request: packet type %d", |
4633 | pktin.type)); |
bc240b21 |
4634 | crReturnV; |
4635 | } |
4636 | logevent("Server refused this port forwarding"); |
4637 | } else { |
4638 | logevent("Remote port forwarding enabled"); |
4639 | } |
4640 | } |
4641 | } |
4642 | } |
4643 | } |
4644 | } |
4645 | |
4646 | /* |
36c2a3e9 |
4647 | * Potentially enable agent forwarding. |
4648 | */ |
4649 | if (cfg.agentfwd && agent_exists()) { |
32874aea |
4650 | logevent("Requesting OpenSSH-style agent forwarding"); |
4651 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
4652 | ssh2_pkt_adduint32(mainchan->remoteid); |
4653 | ssh2_pkt_addstring("auth-agent-req@openssh.com"); |
4654 | ssh2_pkt_addbool(1); /* want reply */ |
4655 | ssh2_pkt_send(); |
4656 | |
4657 | do { |
4658 | crWaitUntilV(ispkt); |
4659 | if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
4660 | unsigned i = ssh2_pkt_getuint32(); |
4661 | struct ssh_channel *c; |
4662 | c = find234(ssh_channels, &i, ssh_channelfind); |
4663 | if (!c) |
4664 | continue; /* nonexistent channel */ |
5471d09a |
4665 | c->v.v2.remwindow += ssh2_pkt_getuint32(); |
32874aea |
4666 | } |
4667 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
4668 | |
4669 | if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
4670 | if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
c9886e66 |
4671 | bombout(("Unexpected response to agent forwarding request:" |
4672 | " packet type %d", pktin.type)); |
32874aea |
4673 | crReturnV; |
4674 | } |
4675 | logevent("Agent forwarding refused"); |
4676 | } else { |
4677 | logevent("Agent forwarding enabled"); |
36c2a3e9 |
4678 | ssh_agentfwd_enabled = TRUE; |
32874aea |
4679 | } |
36c2a3e9 |
4680 | } |
4681 | |
4682 | /* |
7cca0d81 |
4683 | * Now allocate a pty for the session. |
4684 | */ |
67779be7 |
4685 | if (!cfg.nopty) { |
32874aea |
4686 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
4687 | ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */ |
4688 | ssh2_pkt_addstring("pty-req"); |
4689 | ssh2_pkt_addbool(1); /* want reply */ |
4690 | ssh2_pkt_addstring(cfg.termtype); |
4691 | ssh2_pkt_adduint32(cols); |
4692 | ssh2_pkt_adduint32(rows); |
4693 | ssh2_pkt_adduint32(0); /* pixel width */ |
4694 | ssh2_pkt_adduint32(0); /* pixel height */ |
4695 | ssh2_pkt_addstring_start(); |
4696 | ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */ |
4697 | ssh2_pkt_send(); |
4698 | ssh_state = SSH_STATE_INTERMED; |
4699 | |
4700 | do { |
4701 | crWaitUntilV(ispkt); |
4702 | if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
4703 | unsigned i = ssh2_pkt_getuint32(); |
4704 | struct ssh_channel *c; |
4705 | c = find234(ssh_channels, &i, ssh_channelfind); |
4706 | if (!c) |
4707 | continue; /* nonexistent channel */ |
5471d09a |
4708 | c->v.v2.remwindow += ssh2_pkt_getuint32(); |
32874aea |
4709 | } |
4710 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
4711 | |
4712 | if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
4713 | if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
c9886e66 |
4714 | bombout(("Unexpected response to pty request:" |
4715 | " packet type %d", pktin.type)); |
32874aea |
4716 | crReturnV; |
4717 | } |
4718 | c_write_str("Server refused to allocate pty\r\n"); |
4719 | ssh_editing = ssh_echoing = 1; |
4720 | } else { |
4721 | logevent("Allocated pty"); |
4722 | } |
0965bee0 |
4723 | } else { |
32874aea |
4724 | ssh_editing = ssh_echoing = 1; |
7cca0d81 |
4725 | } |
4726 | |
4727 | /* |
fd5e5847 |
4728 | * Start a shell or a remote command. We may have to attempt |
4729 | * this twice if the config data has provided a second choice |
4730 | * of command. |
7cca0d81 |
4731 | */ |
fd5e5847 |
4732 | while (1) { |
4733 | int subsys; |
4734 | char *cmd; |
4735 | |
4736 | if (ssh_fallback_cmd) { |
4737 | subsys = cfg.ssh_subsys2; |
4738 | cmd = cfg.remote_cmd_ptr2; |
4739 | } else { |
4740 | subsys = cfg.ssh_subsys; |
4741 | cmd = cfg.remote_cmd_ptr; |
4742 | } |
4743 | |
4744 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
4745 | ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */ |
4746 | if (subsys) { |
4747 | ssh2_pkt_addstring("subsystem"); |
4748 | ssh2_pkt_addbool(1); /* want reply */ |
4749 | ssh2_pkt_addstring(cmd); |
4750 | } else if (*cmd) { |
4751 | ssh2_pkt_addstring("exec"); |
4752 | ssh2_pkt_addbool(1); /* want reply */ |
4753 | ssh2_pkt_addstring(cmd); |
4754 | } else { |
4755 | ssh2_pkt_addstring("shell"); |
4756 | ssh2_pkt_addbool(1); /* want reply */ |
32874aea |
4757 | } |
fd5e5847 |
4758 | ssh2_pkt_send(); |
4759 | do { |
4760 | crWaitUntilV(ispkt); |
4761 | if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
4762 | unsigned i = ssh2_pkt_getuint32(); |
4763 | struct ssh_channel *c; |
4764 | c = find234(ssh_channels, &i, ssh_channelfind); |
4765 | if (!c) |
4766 | continue; /* nonexistent channel */ |
4767 | c->v.v2.remwindow += ssh2_pkt_getuint32(); |
4768 | } |
4769 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
4770 | if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
4771 | if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
c9886e66 |
4772 | bombout(("Unexpected response to shell/command request:" |
4773 | " packet type %d", pktin.type)); |
fd5e5847 |
4774 | crReturnV; |
4775 | } |
4776 | /* |
4777 | * We failed to start the command. If this is the |
4778 | * fallback command, we really are finished; if it's |
4779 | * not, and if the fallback command exists, try falling |
4780 | * back to it before complaining. |
4781 | */ |
4782 | if (!ssh_fallback_cmd && cfg.remote_cmd_ptr2 != NULL) { |
4783 | logevent("Primary command failed; attempting fallback"); |
4784 | ssh_fallback_cmd = TRUE; |
4785 | continue; |
4786 | } |
4787 | bombout(("Server refused to start a shell/command")); |
32874aea |
4788 | crReturnV; |
fd5e5847 |
4789 | } else { |
4790 | logevent("Started a shell/command"); |
32874aea |
4791 | } |
fd5e5847 |
4792 | break; |
7cca0d81 |
4793 | } |
4794 | |
6e48c3fe |
4795 | ssh_state = SSH_STATE_SESSION; |
4796 | if (size_needed) |
4797 | ssh_size(); |
3687d221 |
4798 | if (eof_needed) |
32874aea |
4799 | ssh_special(TS_EOF); |
6e48c3fe |
4800 | |
7cca0d81 |
4801 | /* |
4802 | * Transfer data! |
4803 | */ |
760e88b2 |
4804 | ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */ |
8ccc75b0 |
4805 | ssh_send_ok = 1; |
7cca0d81 |
4806 | while (1) { |
32874aea |
4807 | static int try_send; |
e5574168 |
4808 | crReturnV; |
32874aea |
4809 | try_send = FALSE; |
7cca0d81 |
4810 | if (ispkt) { |
4811 | if (pktin.type == SSH2_MSG_CHANNEL_DATA || |
32874aea |
4812 | pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) { |
4813 | char *data; |
4814 | int length; |
4815 | unsigned i = ssh2_pkt_getuint32(); |
4816 | struct ssh_channel *c; |
4817 | c = find234(ssh_channels, &i, ssh_channelfind); |
4818 | if (!c) |
4819 | continue; /* nonexistent channel */ |
4820 | if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA && |
4821 | ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR) |
4822 | continue; /* extended but not stderr */ |
4823 | ssh2_pkt_getstring(&data, &length); |
4824 | if (data) { |
5471d09a |
4825 | int bufsize; |
4826 | c->v.v2.locwindow -= length; |
32874aea |
4827 | switch (c->type) { |
4828 | case CHAN_MAINSESSION: |
5471d09a |
4829 | bufsize = |
4830 | from_backend(pktin.type == |
4831 | SSH2_MSG_CHANNEL_EXTENDED_DATA, |
4832 | data, length); |
32874aea |
4833 | break; |
4834 | case CHAN_X11: |
5471d09a |
4835 | bufsize = x11_send(c->u.x11.s, data, length); |
32874aea |
4836 | break; |
d74d141c |
4837 | case CHAN_SOCKDATA: |
5471d09a |
4838 | bufsize = pfd_send(c->u.pfd.s, data, length); |
bc240b21 |
4839 | break; |
36c2a3e9 |
4840 | case CHAN_AGENT: |
32874aea |
4841 | while (length > 0) { |
4842 | if (c->u.a.lensofar < 4) { |
4843 | int l = min(4 - c->u.a.lensofar, length); |
4844 | memcpy(c->u.a.msglen + c->u.a.lensofar, |
4845 | data, l); |
4846 | data += l; |
4847 | length -= l; |
4848 | c->u.a.lensofar += l; |
4849 | } |
4850 | if (c->u.a.lensofar == 4) { |
4851 | c->u.a.totallen = |
4852 | 4 + GET_32BIT(c->u.a.msglen); |
4853 | c->u.a.message = smalloc(c->u.a.totallen); |
4854 | memcpy(c->u.a.message, c->u.a.msglen, 4); |
4855 | } |
4856 | if (c->u.a.lensofar >= 4 && length > 0) { |
4857 | int l = |
4858 | min(c->u.a.totallen - c->u.a.lensofar, |
4859 | length); |
4860 | memcpy(c->u.a.message + c->u.a.lensofar, |
4861 | data, l); |
4862 | data += l; |
4863 | length -= l; |
4864 | c->u.a.lensofar += l; |
4865 | } |
4866 | if (c->u.a.lensofar == c->u.a.totallen) { |
4867 | void *reply, *sentreply; |
4868 | int replylen; |
4869 | agent_query(c->u.a.message, |
4870 | c->u.a.totallen, &reply, |
4871 | &replylen); |
4872 | if (reply) |
4873 | sentreply = reply; |
4874 | else { |
4875 | /* Fake SSH_AGENT_FAILURE. */ |
4876 | sentreply = "\0\0\0\1\5"; |
4877 | replylen = 5; |
4878 | } |
4879 | ssh2_add_channel_data(c, sentreply, |
4880 | replylen); |
36c2a3e9 |
4881 | try_send = TRUE; |
32874aea |
4882 | if (reply) |
4883 | sfree(reply); |
4884 | sfree(c->u.a.message); |
4885 | c->u.a.lensofar = 0; |
4886 | } |
4887 | } |
5471d09a |
4888 | bufsize = 0; |
32874aea |
4889 | break; |
4890 | } |
4891 | /* |
5471d09a |
4892 | * If we are not buffering too much data, |
4893 | * enlarge the window again at the remote side. |
32874aea |
4894 | */ |
5471d09a |
4895 | if (bufsize < OUR_V2_WINSIZE) |
4896 | ssh2_set_window(c, OUR_V2_WINSIZE - bufsize); |
32874aea |
4897 | } |
7cca0d81 |
4898 | } else if (pktin.type == SSH2_MSG_DISCONNECT) { |
32874aea |
4899 | ssh_state = SSH_STATE_CLOSED; |
d211621f |
4900 | logevent("Received disconnect message"); |
32874aea |
4901 | crReturnV; |
d211621f |
4902 | } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) { |
32874aea |
4903 | unsigned i = ssh2_pkt_getuint32(); |
4904 | struct ssh_channel *c; |
4905 | |
4906 | c = find234(ssh_channels, &i, ssh_channelfind); |
4907 | if (!c) |
4908 | continue; /* nonexistent channel */ |
4909 | |
4910 | if (c->type == CHAN_X11) { |
4911 | /* |
4912 | * Remote EOF on an X11 channel means we should |
4913 | * wrap up and close the channel ourselves. |
4914 | */ |
4915 | x11_close(c->u.x11.s); |
4916 | sshfwd_close(c); |
4917 | } else if (c->type == CHAN_AGENT) { |
36c2a3e9 |
4918 | sshfwd_close(c); |
d74d141c |
4919 | } else if (c->type == CHAN_SOCKDATA) { |
bc240b21 |
4920 | pfd_close(c->u.pfd.s); |
4921 | sshfwd_close(c); |
36c2a3e9 |
4922 | } |
d211621f |
4923 | } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) { |
32874aea |
4924 | unsigned i = ssh2_pkt_getuint32(); |
4925 | struct ssh_channel *c; |
4926 | |
4927 | c = find234(ssh_channels, &i, ssh_channelfind); |
4928 | if (!c) |
4929 | continue; /* nonexistent channel */ |
32874aea |
4930 | /* Do pre-close processing on the channel. */ |
4931 | switch (c->type) { |
4932 | case CHAN_MAINSESSION: |
4933 | break; /* nothing to see here, move along */ |
4934 | case CHAN_X11: |
92f157bd |
4935 | if (c->u.x11.s != NULL) |
4936 | x11_close(c->u.x11.s); |
4937 | sshfwd_close(c); |
32874aea |
4938 | break; |
4939 | case CHAN_AGENT: |
92f157bd |
4940 | sshfwd_close(c); |
32874aea |
4941 | break; |
d74d141c |
4942 | case CHAN_SOCKDATA: |
92f157bd |
4943 | if (c->u.pfd.s != NULL) |
4944 | pfd_close(c->u.pfd.s); |
4945 | sshfwd_close(c); |
bc240b21 |
4946 | break; |
32874aea |
4947 | } |
92f157bd |
4948 | if (c->closes == 0) { |
4949 | ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); |
4950 | ssh2_pkt_adduint32(c->remoteid); |
4951 | ssh2_pkt_send(); |
4952 | } |
32874aea |
4953 | del234(ssh_channels, c); |
5471d09a |
4954 | bufchain_clear(&c->v.v2.outbuffer); |
32874aea |
4955 | sfree(c); |
4956 | |
4957 | /* |
4958 | * See if that was the last channel left open. |
4959 | */ |
4960 | if (count234(ssh_channels) == 0) { |
ca2914d1 |
4961 | #if 0 |
4962 | /* |
4963 | * We used to send SSH_MSG_DISCONNECT here, |
4964 | * because I'd believed that _every_ conforming |
4965 | * SSH2 connection had to end with a disconnect |
4966 | * being sent by at least one side; apparently |
4967 | * I was wrong and it's perfectly OK to |
4968 | * unceremoniously slam the connection shut |
4969 | * when you're done, and indeed OpenSSH feels |
4970 | * this is more polite than sending a |
4971 | * DISCONNECT. So now we don't. |
4972 | */ |
32874aea |
4973 | logevent("All channels closed. Disconnecting"); |
4974 | ssh2_pkt_init(SSH2_MSG_DISCONNECT); |
4975 | ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION); |
4976 | ssh2_pkt_addstring("All open channels closed"); |
4977 | ssh2_pkt_addstring("en"); /* language tag */ |
4978 | ssh2_pkt_send(); |
ca2914d1 |
4979 | #endif |
32874aea |
4980 | ssh_state = SSH_STATE_CLOSED; |
4981 | crReturnV; |
4982 | } |
4983 | continue; /* remote sends close; ignore (FIXME) */ |
7cca0d81 |
4984 | } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
32874aea |
4985 | unsigned i = ssh2_pkt_getuint32(); |
4986 | struct ssh_channel *c; |
4987 | c = find234(ssh_channels, &i, ssh_channelfind); |
4988 | if (!c) |
4989 | continue; /* nonexistent channel */ |
5471d09a |
4990 | c->v.v2.remwindow += ssh2_pkt_getuint32(); |
32874aea |
4991 | try_send = TRUE; |
bc240b21 |
4992 | } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) { |
4993 | unsigned i = ssh2_pkt_getuint32(); |
4994 | struct ssh_channel *c; |
4995 | c = find234(ssh_channels, &i, ssh_channelfind); |
4996 | if (!c) |
4997 | continue; /* nonexistent channel */ |
4998 | if (c->type != CHAN_SOCKDATA_DORMANT) |
4999 | continue; /* dunno why they're confirming this */ |
5000 | c->remoteid = ssh2_pkt_getuint32(); |
5001 | c->type = CHAN_SOCKDATA; |
5471d09a |
5002 | c->v.v2.remwindow = ssh2_pkt_getuint32(); |
5003 | c->v.v2.remmaxpkt = ssh2_pkt_getuint32(); |
5004 | bufchain_init(&c->v.v2.outbuffer); |
4ed34d25 |
5005 | if (c->u.pfd.s) |
5006 | pfd_confirm(c->u.pfd.s); |
5007 | if (c->closes) { |
5008 | /* |
5009 | * We have a pending close on this channel, |
5010 | * which we decided on before the server acked |
5011 | * the channel open. So now we know the |
5012 | * remoteid, we can close it again. |
5013 | */ |
5014 | ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); |
5015 | ssh2_pkt_adduint32(c->remoteid); |
5016 | ssh2_pkt_send(); |
5017 | } |
724cface |
5018 | } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) { |
5019 | unsigned i = ssh2_pkt_getuint32(); |
5020 | struct ssh_channel *c; |
5021 | c = find234(ssh_channels, &i, ssh_channelfind); |
5022 | if (!c) |
5023 | continue; /* nonexistent channel */ |
5024 | if (c->type != CHAN_SOCKDATA_DORMANT) |
5025 | continue; /* dunno why they're failing this */ |
5026 | |
5027 | logevent("Forwarded connection refused by server"); |
5028 | |
5029 | pfd_close(c->u.pfd.s); |
5030 | |
5031 | del234(ssh_channels, c); |
5032 | sfree(c); |
ebb0a590 |
5033 | } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) { |
5034 | unsigned localid; |
5035 | char *type; |
5036 | int typelen, want_reply; |
5037 | struct ssh_channel *c; |
5038 | |
5039 | localid = ssh2_pkt_getuint32(); |
5040 | ssh2_pkt_getstring(&type, &typelen); |
5041 | want_reply = ssh2_pkt_getbool(); |
5042 | |
5043 | /* |
5044 | * First, check that the channel exists. Otherwise, |
5045 | * we can instantly disconnect with a rude message. |
5046 | */ |
5047 | c = find234(ssh_channels, &localid, ssh_channelfind); |
5048 | if (!c) { |
5049 | char buf[80]; |
5050 | sprintf(buf, "Received channel request for nonexistent" |
5051 | " channel %d", localid); |
5052 | logevent(buf); |
5053 | ssh2_pkt_init(SSH2_MSG_DISCONNECT); |
5054 | ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION); |
5055 | ssh2_pkt_addstring(buf); |
5056 | ssh2_pkt_addstring("en"); /* language tag */ |
5057 | ssh2_pkt_send(); |
5058 | connection_fatal(buf); |
5059 | ssh_state = SSH_STATE_CLOSED; |
5060 | crReturnV; |
5061 | } |
5062 | |
5063 | /* |
5064 | * We don't recognise any form of channel request, |
5065 | * so we now either ignore the request or respond |
5066 | * with CHANNEL_FAILURE, depending on want_reply. |
5067 | */ |
5068 | if (want_reply) { |
5069 | ssh2_pkt_init(SSH2_MSG_CHANNEL_FAILURE); |
5070 | ssh2_pkt_adduint32(c->remoteid); |
5071 | ssh2_pkt_send(); |
5072 | } |
783415f8 |
5073 | } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) { |
32874aea |
5074 | char *type; |
5075 | int typelen; |
5076 | char *error = NULL; |
5077 | struct ssh_channel *c; |
bc240b21 |
5078 | unsigned remid, winsize, pktsize; |
32874aea |
5079 | ssh2_pkt_getstring(&type, &typelen); |
5080 | c = smalloc(sizeof(struct ssh_channel)); |
5081 | |
bc240b21 |
5082 | remid = ssh2_pkt_getuint32(); |
5083 | winsize = ssh2_pkt_getuint32(); |
5084 | pktsize = ssh2_pkt_getuint32(); |
5085 | |
32874aea |
5086 | if (typelen == 3 && !memcmp(type, "x11", 3)) { |
5087 | if (!ssh_X11_fwd_enabled) |
5088 | error = "X11 forwarding is not enabled"; |
5089 | else if (x11_init(&c->u.x11.s, cfg.x11_display, c) != |
5090 | NULL) { |
5091 | error = "Unable to open an X11 connection"; |
5092 | } else { |
5093 | c->type = CHAN_X11; |
5094 | } |
bc240b21 |
5095 | } else if (typelen == 15 && |
5096 | !memcmp(type, "forwarded-tcpip", 15)) { |
5097 | struct ssh_rportfwd pf, *realpf; |
5098 | char *dummy; |
5099 | int dummylen; |
5100 | ssh2_pkt_getstring(&dummy, &dummylen);/* skip address */ |
5101 | pf.sport = ssh2_pkt_getuint32(); |
5102 | realpf = find234(ssh_rportfwds, &pf, NULL); |
5103 | if (realpf == NULL) { |
5104 | error = "Remote port is not recognised"; |
5105 | } else { |
5106 | char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost, |
5107 | realpf->dport, c); |
5108 | char buf[1024]; |
5109 | sprintf(buf, "Received remote port open request for %s:%d", |
5110 | realpf->dhost, realpf->dport); |
5111 | logevent(buf); |
5112 | if (e != NULL) { |
5113 | sprintf(buf, "Port open failed: %s", e); |
5114 | logevent(buf); |
5115 | error = "Port open failed"; |
5116 | } else { |
5117 | logevent("Forwarded port opened successfully"); |
5118 | c->type = CHAN_SOCKDATA; |
5119 | } |
5120 | } |
32874aea |
5121 | } else if (typelen == 22 && |
36c2a3e9 |
5122 | !memcmp(type, "auth-agent@openssh.com", 3)) { |
32874aea |
5123 | if (!ssh_agentfwd_enabled) |
5124 | error = "Agent forwarding is not enabled"; |
36c2a3e9 |
5125 | else { |
32874aea |
5126 | c->type = CHAN_AGENT; /* identify channel type */ |
36c2a3e9 |
5127 | c->u.a.lensofar = 0; |
32874aea |
5128 | } |
5129 | } else { |
5130 | error = "Unsupported channel type requested"; |
5131 | } |
5132 | |
bc240b21 |
5133 | c->remoteid = remid; |
32874aea |
5134 | if (error) { |
5135 | ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE); |
5136 | ssh2_pkt_adduint32(c->remoteid); |
5137 | ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED); |
5138 | ssh2_pkt_addstring(error); |
5139 | ssh2_pkt_addstring("en"); /* language tag */ |
5140 | ssh2_pkt_send(); |
5141 | sfree(c); |
5142 | } else { |
5143 | c->localid = alloc_channel_id(); |
5144 | c->closes = 0; |
5471d09a |
5145 | c->v.v2.locwindow = OUR_V2_WINSIZE; |
5146 | c->v.v2.remwindow = winsize; |
5147 | c->v.v2.remmaxpkt = pktsize; |
5148 | bufchain_init(&c->v.v2.outbuffer); |
32874aea |
5149 | add234(ssh_channels, c); |
5150 | ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); |
5151 | ssh2_pkt_adduint32(c->remoteid); |
5152 | ssh2_pkt_adduint32(c->localid); |
5471d09a |
5153 | ssh2_pkt_adduint32(c->v.v2.locwindow); |
32874aea |
5154 | ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */ |
5155 | ssh2_pkt_send(); |
5156 | } |
7cca0d81 |
5157 | } else { |
8d5de777 |
5158 | bombout(("Strange packet received: type %d", pktin.type)); |
32874aea |
5159 | crReturnV; |
7cca0d81 |
5160 | } |
5161 | } else { |
32874aea |
5162 | /* |
5163 | * We have spare data. Add it to the channel buffer. |
5164 | */ |
5165 | ssh2_add_channel_data(mainchan, in, inlen); |
5166 | try_send = TRUE; |
5167 | } |
5168 | if (try_send) { |
5169 | int i; |
5170 | struct ssh_channel *c; |
5171 | /* |
5172 | * Try to send data on all channels if we can. |
5173 | */ |
5471d09a |
5174 | for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) { |
5175 | int bufsize = ssh2_try_send(c); |
5176 | if (bufsize == 0) { |
5177 | switch (c->type) { |
5178 | case CHAN_MAINSESSION: |
5179 | /* stdin need not receive an unthrottle |
5180 | * notification since it will be polled */ |
5181 | break; |
5182 | case CHAN_X11: |
5183 | x11_unthrottle(c->u.x11.s); |
5184 | break; |
5185 | case CHAN_AGENT: |
5186 | /* agent sockets are request/response and need no |
5187 | * buffer management */ |
5188 | break; |
5189 | case CHAN_SOCKDATA: |
5190 | pfd_unthrottle(c->u.pfd.s); |
5191 | break; |
5192 | } |
5193 | } |
5194 | } |
7cca0d81 |
5195 | } |
e5574168 |
5196 | } |
5197 | |
5198 | crFinishV; |
5199 | } |
5200 | |
5201 | /* |
7cca0d81 |
5202 | * Handle the top-level SSH2 protocol. |
5203 | */ |
5204 | static void ssh2_protocol(unsigned char *in, int inlen, int ispkt) |
5205 | { |
5206 | if (do_ssh2_transport(in, inlen, ispkt) == 0) |
32874aea |
5207 | return; |
7cca0d81 |
5208 | do_ssh2_authconn(in, inlen, ispkt); |
5209 | } |
5210 | |
5211 | /* |
8df7a775 |
5212 | * Called to set up the connection. |
374330e2 |
5213 | * |
5214 | * Returns an error message, or NULL on success. |
374330e2 |
5215 | */ |
2184a5d9 |
5216 | static char *ssh_init(char *host, int port, char **realhost, int nodelay) |
32874aea |
5217 | { |
fb09bf1c |
5218 | char *p; |
32874aea |
5219 | |
8f203108 |
5220 | #ifdef MSCRYPTOAPI |
32874aea |
5221 | if (crypto_startup() == 0) |
8f203108 |
5222 | return "Microsoft high encryption pack not installed!"; |
5223 | #endif |
374330e2 |
5224 | |
8df7a775 |
5225 | ssh_send_ok = 0; |
0965bee0 |
5226 | ssh_editing = 0; |
5227 | ssh_echoing = 0; |
5471d09a |
5228 | ssh1_throttle_count = 0; |
5229 | ssh_overall_bufsize = 0; |
fd5e5847 |
5230 | ssh_fallback_cmd = 0; |
8df7a775 |
5231 | |
2184a5d9 |
5232 | p = connect_to_host(host, port, realhost, nodelay); |
fb09bf1c |
5233 | if (p != NULL) |
5234 | return p; |
374330e2 |
5235 | |
374330e2 |
5236 | return NULL; |
5237 | } |
5238 | |
5239 | /* |
374330e2 |
5240 | * Called to send data down the Telnet connection. |
5241 | */ |
5471d09a |
5242 | static int ssh_send(char *buf, int len) |
32874aea |
5243 | { |
f78051a1 |
5244 | if (s == NULL || ssh_protocol == NULL) |
5471d09a |
5245 | return 0; |
374330e2 |
5246 | |
5247 | ssh_protocol(buf, len, 0); |
5471d09a |
5248 | |
5249 | return ssh_sendbuffer(); |
5250 | } |
5251 | |
5252 | /* |
5253 | * Called to query the current amount of buffered stdin data. |
5254 | */ |
5255 | static int ssh_sendbuffer(void) |
5256 | { |
5257 | int override_value; |
5258 | |
5259 | if (s == NULL || ssh_protocol == NULL) |
5260 | return 0; |
5261 | |
5262 | /* |
5263 | * If the SSH socket itself has backed up, add the total backup |
5264 | * size on that to any individual buffer on the stdin channel. |
5265 | */ |
5266 | override_value = 0; |
5267 | if (ssh_throttled_all) |
5268 | override_value = ssh_overall_bufsize; |
5269 | |
5270 | if (ssh_version == 1) { |
5271 | return override_value; |
5272 | } else if (ssh_version == 2) { |
5273 | if (!mainchan || mainchan->closes > 0) |
5274 | return override_value; |
5275 | else |
5276 | return override_value + bufchain_size(&mainchan->v.v2.outbuffer); |
5277 | } |
5278 | |
5279 | return 0; |
374330e2 |
5280 | } |
5281 | |
5282 | /* |
6e48c3fe |
5283 | * Called to set the size of the window from SSH's POV. |
374330e2 |
5284 | */ |
32874aea |
5285 | static void ssh_size(void) |
5286 | { |
374330e2 |
5287 | switch (ssh_state) { |
5288 | case SSH_STATE_BEFORE_SIZE: |
3687d221 |
5289 | case SSH_STATE_PREPACKET: |
21248260 |
5290 | case SSH_STATE_CLOSED: |
374330e2 |
5291 | break; /* do nothing */ |
5292 | case SSH_STATE_INTERMED: |
5293 | size_needed = TRUE; /* buffer for later */ |
5294 | break; |
5295 | case SSH_STATE_SESSION: |
32874aea |
5296 | if (!cfg.nopty) { |
5297 | if (ssh_version == 1) { |
5298 | send_packet(SSH1_CMSG_WINDOW_SIZE, |
5299 | PKT_INT, rows, PKT_INT, cols, |
5300 | PKT_INT, 0, PKT_INT, 0, PKT_END); |
5301 | } else { |
5302 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
5303 | ssh2_pkt_adduint32(mainchan->remoteid); |
5304 | ssh2_pkt_addstring("window-change"); |
5305 | ssh2_pkt_addbool(0); |
5306 | ssh2_pkt_adduint32(cols); |
5307 | ssh2_pkt_adduint32(rows); |
5308 | ssh2_pkt_adduint32(0); |
5309 | ssh2_pkt_adduint32(0); |
5310 | ssh2_pkt_send(); |
5311 | } |
5312 | } |
5313 | break; |
374330e2 |
5314 | } |
5315 | } |
5316 | |
5317 | /* |
6abbf9e3 |
5318 | * Send Telnet special codes. TS_EOF is useful for `plink', so you |
5319 | * can send an EOF and collect resulting output (e.g. `plink |
5320 | * hostname sort'). |
374330e2 |
5321 | */ |
32874aea |
5322 | static void ssh_special(Telnet_Special code) |
5323 | { |
6abbf9e3 |
5324 | if (code == TS_EOF) { |
32874aea |
5325 | if (ssh_state != SSH_STATE_SESSION) { |
5326 | /* |
5327 | * Buffer the EOF in case we are pre-SESSION, so we can |
5328 | * send it as soon as we reach SESSION. |
5329 | */ |
5330 | if (code == TS_EOF) |
5331 | eof_needed = TRUE; |
5332 | return; |
5333 | } |
5334 | if (ssh_version == 1) { |
5335 | send_packet(SSH1_CMSG_EOF, PKT_END); |
5336 | } else { |
5337 | ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF); |
5338 | ssh2_pkt_adduint32(mainchan->remoteid); |
5339 | ssh2_pkt_send(); |
5340 | } |
5341 | logevent("Sent EOF message"); |
ec55b220 |
5342 | } else if (code == TS_PING) { |
32874aea |
5343 | if (ssh_state == SSH_STATE_CLOSED |
5344 | || ssh_state == SSH_STATE_PREPACKET) return; |
5345 | if (ssh_version == 1) { |
5346 | send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END); |
5347 | } else { |
5348 | ssh2_pkt_init(SSH2_MSG_IGNORE); |
5349 | ssh2_pkt_addstring_start(); |
5350 | ssh2_pkt_send(); |
5351 | } |
6abbf9e3 |
5352 | } else { |
32874aea |
5353 | /* do nothing */ |
6abbf9e3 |
5354 | } |
374330e2 |
5355 | } |
5356 | |
d74d141c |
5357 | void *new_sock_channel(Socket s) |
5358 | { |
5359 | struct ssh_channel *c; |
5360 | c = smalloc(sizeof(struct ssh_channel)); |
5361 | |
5362 | if (c) { |
bc240b21 |
5363 | c->remoteid = -1; /* to be set when open confirmed */ |
d74d141c |
5364 | c->localid = alloc_channel_id(); |
5365 | c->closes = 0; |
bc240b21 |
5366 | c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */ |
d74d141c |
5367 | c->u.pfd.s = s; |
5368 | add234(ssh_channels, c); |
5369 | } |
5370 | return c; |
5371 | } |
5372 | |
5471d09a |
5373 | /* |
5374 | * This is called when stdout/stderr (the entity to which |
5375 | * from_backend sends data) manages to clear some backlog. |
5376 | */ |
5377 | void ssh_unthrottle(int bufsize) |
5378 | { |
5379 | if (ssh_version == 1) { |
90347b95 |
5380 | if (ssh1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) { |
5471d09a |
5381 | ssh1_stdout_throttling = 0; |
5382 | ssh1_throttle(-1); |
5383 | } |
5384 | } else { |
5385 | if (mainchan && mainchan->closes == 0) |
5386 | ssh2_set_window(mainchan, OUR_V2_WINSIZE - bufsize); |
5387 | } |
5388 | } |
5389 | |
d74d141c |
5390 | void ssh_send_port_open(void *channel, char *hostname, int port, char *org) |
5391 | { |
5392 | struct ssh_channel *c = (struct ssh_channel *)channel; |
5393 | char buf[1024]; |
5394 | |
5395 | sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port); |
5396 | logevent(buf); |
5397 | |
bc240b21 |
5398 | if (ssh_version == 1) { |
5399 | send_packet(SSH1_MSG_PORT_OPEN, |
5400 | PKT_INT, c->localid, |
5401 | PKT_STR, hostname, |
5402 | PKT_INT, port, |
5403 | //PKT_STR, <org:orgport>, |
5404 | PKT_END); |
5405 | } else { |
5406 | ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN); |
5407 | ssh2_pkt_addstring("direct-tcpip"); |
5408 | ssh2_pkt_adduint32(c->localid); |
5471d09a |
5409 | c->v.v2.locwindow = OUR_V2_WINSIZE; |
5410 | ssh2_pkt_adduint32(c->v.v2.locwindow);/* our window size */ |
bc240b21 |
5411 | ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */ |
5412 | ssh2_pkt_addstring(hostname); |
5413 | ssh2_pkt_adduint32(port); |
5414 | /* |
5415 | * We make up values for the originator data; partly it's |
5416 | * too much hassle to keep track, and partly I'm not |
5417 | * convinced the server should be told details like that |
5418 | * about my local network configuration. |
5419 | */ |
5420 | ssh2_pkt_addstring("client-side-connection"); |
5421 | ssh2_pkt_adduint32(0); |
5422 | ssh2_pkt_send(); |
5423 | } |
d74d141c |
5424 | } |
5425 | |
5426 | |
32874aea |
5427 | static Socket ssh_socket(void) |
5428 | { |
5429 | return s; |
5430 | } |
8ccc75b0 |
5431 | |
32874aea |
5432 | static int ssh_sendok(void) |
5433 | { |
5434 | return ssh_send_ok; |
5435 | } |
fb09bf1c |
5436 | |
32874aea |
5437 | static int ssh_ldisc(int option) |
5438 | { |
5439 | if (option == LD_ECHO) |
5440 | return ssh_echoing; |
5441 | if (option == LD_EDIT) |
5442 | return ssh_editing; |
0965bee0 |
5443 | return FALSE; |
5444 | } |
5445 | |
374330e2 |
5446 | Backend ssh_backend = { |
5447 | ssh_init, |
374330e2 |
5448 | ssh_send, |
5471d09a |
5449 | ssh_sendbuffer, |
374330e2 |
5450 | ssh_size, |
4017be6d |
5451 | ssh_special, |
8ccc75b0 |
5452 | ssh_socket, |
97db3be4 |
5453 | ssh_sendok, |
0965bee0 |
5454 | ssh_ldisc, |
5471d09a |
5455 | ssh_unthrottle, |
97db3be4 |
5456 | 22 |
bc240b21 |
5457 | }; |