8df7a775 |
1 | #include <windows.h> |
374330e2 |
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 | |
765c4200 |
18 | /* uncomment this for packet level debugging */ |
19 | /* #define DUMP_PACKETS */ |
20 | |
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21 | #define logevent(s) { logevent(s); \ |
67779be7 |
22 | if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \ |
b4453f49 |
23 | { fprintf(stderr, "%s\n", s); fflush(stderr); } } |
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24 | |
3cd52910 |
25 | #define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \ |
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26 | (s ? sk_close(s), s = NULL : 0), \ |
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27 | connection_fatal msg ) |
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28 | |
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29 | #define SSH1_MSG_DISCONNECT 1 /* 0x1 */ |
30 | #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */ |
31 | #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */ |
32 | #define SSH1_CMSG_USER 4 /* 0x4 */ |
33 | #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */ |
34 | #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */ |
35 | #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */ |
36 | #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */ |
37 | #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */ |
38 | #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */ |
39 | #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */ |
40 | #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */ |
41 | #define SSH1_SMSG_SUCCESS 14 /* 0xe */ |
42 | #define SSH1_SMSG_FAILURE 15 /* 0xf */ |
43 | #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */ |
44 | #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */ |
45 | #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */ |
46 | #define SSH1_CMSG_EOF 19 /* 0x13 */ |
47 | #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */ |
48 | #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */ |
49 | #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */ |
50 | #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */ |
51 | #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */ |
52 | #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */ |
9c964e85 |
53 | #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */ |
54 | #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */ |
55 | #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */ |
d211621f |
56 | #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */ |
57 | #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */ |
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58 | #define SSH1_MSG_IGNORE 32 /* 0x20 */ |
9c964e85 |
59 | #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */ |
60 | #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */ |
61 | #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */ |
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62 | #define SSH1_MSG_DEBUG 36 /* 0x24 */ |
4ba9b64b |
63 | #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */ |
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64 | #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */ |
65 | #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */ |
66 | #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */ |
67 | #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */ |
68 | #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */ |
69 | #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */ |
70 | |
71 | #define SSH1_AUTH_TIS 5 /* 0x5 */ |
72 | #define SSH1_AUTH_CCARD 16 /* 0x10 */ |
73 | |
b96dc54c |
74 | #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */ |
75 | /* Mask for protoflags we will echo back to server if seen */ |
76 | #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */ |
77 | |
d211621f |
78 | #define SSH2_MSG_DISCONNECT 1 /* 0x1 */ |
79 | #define SSH2_MSG_IGNORE 2 /* 0x2 */ |
80 | #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */ |
81 | #define SSH2_MSG_DEBUG 4 /* 0x4 */ |
82 | #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */ |
83 | #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */ |
84 | #define SSH2_MSG_KEXINIT 20 /* 0x14 */ |
85 | #define SSH2_MSG_NEWKEYS 21 /* 0x15 */ |
86 | #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */ |
87 | #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */ |
a92dd380 |
88 | #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */ |
89 | #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */ |
90 | #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */ |
91 | #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */ |
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92 | #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */ |
93 | #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */ |
94 | #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */ |
95 | #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */ |
96 | #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */ |
97 | #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */ |
98 | #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */ |
99 | #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */ |
100 | #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */ |
101 | #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */ |
102 | #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */ |
103 | #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */ |
104 | #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */ |
105 | #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */ |
106 | #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */ |
107 | #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */ |
108 | #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */ |
109 | #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */ |
110 | #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */ |
111 | #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */ |
112 | |
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113 | #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */ |
114 | #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */ |
115 | #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */ |
116 | #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */ |
117 | #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */ |
118 | #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */ |
119 | #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */ |
120 | #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */ |
121 | #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */ |
122 | #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */ |
123 | #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */ |
38c4a8da |
124 | #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */ |
125 | #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */ |
126 | #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */ |
127 | #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */ |
128 | |
129 | static const char *const ssh2_disconnect_reasons[] = { |
130 | NULL, |
131 | "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT", |
132 | "SSH_DISCONNECT_PROTOCOL_ERROR", |
133 | "SSH_DISCONNECT_KEY_EXCHANGE_FAILED", |
134 | "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED", |
135 | "SSH_DISCONNECT_MAC_ERROR", |
136 | "SSH_DISCONNECT_COMPRESSION_ERROR", |
137 | "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE", |
138 | "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED", |
139 | "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE", |
140 | "SSH_DISCONNECT_CONNECTION_LOST", |
141 | "SSH_DISCONNECT_BY_APPLICATION", |
142 | "SSH_DISCONNECT_TOO_MANY_CONNECTIONS", |
143 | "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER", |
144 | "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE", |
145 | "SSH_DISCONNECT_ILLEGAL_USER_NAME", |
146 | }; |
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147 | |
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148 | #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */ |
149 | #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */ |
150 | #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */ |
151 | #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */ |
152 | |
153 | #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */ |
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154 | |
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155 | /* |
156 | * Various remote-bug flags. |
157 | */ |
158 | #define BUG_CHOKES_ON_SSH1_IGNORE 1 |
159 | #define BUG_SSH2_HMAC 2 |
160 | |
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161 | #define GET_32BIT(cp) \ |
162 | (((unsigned long)(unsigned char)(cp)[0] << 24) | \ |
163 | ((unsigned long)(unsigned char)(cp)[1] << 16) | \ |
164 | ((unsigned long)(unsigned char)(cp)[2] << 8) | \ |
165 | ((unsigned long)(unsigned char)(cp)[3])) |
166 | |
167 | #define PUT_32BIT(cp, value) { \ |
168 | (cp)[0] = (unsigned char)((value) >> 24); \ |
169 | (cp)[1] = (unsigned char)((value) >> 16); \ |
170 | (cp)[2] = (unsigned char)((value) >> 8); \ |
171 | (cp)[3] = (unsigned char)(value); } |
172 | |
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173 | enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM }; |
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174 | |
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175 | /* Coroutine mechanics for the sillier bits of the code */ |
176 | #define crBegin1 static int crLine = 0; |
177 | #define crBegin2 switch(crLine) { case 0:; |
178 | #define crBegin crBegin1; crBegin2; |
179 | #define crFinish(z) } crLine = 0; return (z) |
180 | #define crFinishV } crLine = 0; return |
181 | #define crReturn(z) \ |
182 | do {\ |
183 | crLine=__LINE__; return (z); case __LINE__:;\ |
184 | } while (0) |
185 | #define crReturnV \ |
186 | do {\ |
187 | crLine=__LINE__; return; case __LINE__:;\ |
188 | } while (0) |
189 | #define crStop(z) do{ crLine = 0; return (z); }while(0) |
190 | #define crStopV do{ crLine = 0; return; }while(0) |
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191 | #define crWaitUntil(c) do { crReturn(0); } while (!(c)) |
7cca0d81 |
192 | #define crWaitUntilV(c) do { crReturnV; } while (!(c)) |
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193 | |
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194 | extern char *x11_init (Socket *, char *, void *); |
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195 | extern void x11_close (Socket); |
196 | extern void x11_send (Socket , char *, int); |
197 | extern void x11_invent_auth(char *, int, char *, int); |
198 | |
5e8358ad |
199 | /* |
200 | * Ciphers for SSH2. We miss out single-DES because it isn't |
201 | * supported; also 3DES and Blowfish are both done differently from |
202 | * SSH1. (3DES uses outer chaining; Blowfish has the opposite |
203 | * endianness and different-sized keys.) |
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204 | */ |
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205 | const static struct ssh2_ciphers *ciphers[] = { |
206 | &ssh2_aes, |
207 | &ssh2_blowfish, |
208 | &ssh2_3des, |
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209 | }; |
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210 | |
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211 | const static struct ssh_kex *kex_algs[] = { |
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212 | &ssh_diffiehellman_gex, |
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213 | &ssh_diffiehellman }; |
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214 | |
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215 | const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss }; |
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216 | |
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217 | static void nullmac_key(unsigned char *key) { } |
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218 | static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { } |
219 | static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; } |
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220 | const static struct ssh_mac ssh_mac_none = { |
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221 | nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0 |
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222 | }; |
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223 | const static struct ssh_mac *macs[] = { |
224 | &ssh_sha1, &ssh_md5, &ssh_mac_none }; |
225 | const static struct ssh_mac *buggymacs[] = { |
226 | &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none }; |
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227 | |
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228 | static void ssh_comp_none_init(void) { } |
229 | static int ssh_comp_none_block(unsigned char *block, int len, |
230 | unsigned char **outblock, int *outlen) { |
231 | return 0; |
232 | } |
63b00c83 |
233 | static int ssh_comp_none_disable(void) { return 0; } |
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234 | const static struct ssh_compress ssh_comp_none = { |
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235 | "none", |
236 | ssh_comp_none_init, ssh_comp_none_block, |
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237 | ssh_comp_none_init, ssh_comp_none_block, |
238 | ssh_comp_none_disable |
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239 | }; |
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240 | extern const struct ssh_compress ssh_zlib; |
241 | const static struct ssh_compress *compressions[] = { |
242 | &ssh_zlib, &ssh_comp_none }; |
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243 | |
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244 | enum { /* channel types */ |
245 | CHAN_MAINSESSION, |
246 | CHAN_X11, |
247 | CHAN_AGENT, |
248 | }; |
249 | |
dacbd0e8 |
250 | /* |
251 | * 2-3-4 tree storing channels. |
252 | */ |
253 | struct ssh_channel { |
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254 | unsigned remoteid, localid; |
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255 | int type; |
256 | int closes; |
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257 | struct ssh2_data_channel { |
258 | unsigned char *outbuffer; |
259 | unsigned outbuflen, outbufsize; |
260 | unsigned remwindow, remmaxpkt; |
261 | } v2; |
dacbd0e8 |
262 | union { |
263 | struct ssh_agent_channel { |
264 | unsigned char *message; |
265 | unsigned char msglen[4]; |
266 | int lensofar, totallen; |
267 | } a; |
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268 | struct ssh_x11_channel { |
269 | Socket s; |
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270 | } x11; |
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271 | } u; |
272 | }; |
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273 | |
274 | struct Packet { |
275 | long length; |
276 | int type; |
277 | unsigned char *data; |
278 | unsigned char *body; |
279 | long savedpos; |
280 | long maxlen; |
281 | }; |
282 | |
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283 | static SHA_State exhash, exhashbase; |
57476f6b |
284 | |
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285 | static Socket s = NULL; |
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286 | |
287 | static unsigned char session_key[32]; |
4ba9b64b |
288 | static int ssh1_compressing; |
b96dc54c |
289 | static int ssh1_remote_protoflags; |
290 | static int ssh1_local_protoflags; |
db7d555c |
291 | static int ssh_agentfwd_enabled; |
9c964e85 |
292 | static int ssh_X11_fwd_enabled; |
7d503c31 |
293 | static int ssh_remote_bugs; |
57476f6b |
294 | static const struct ssh_cipher *cipher = NULL; |
0a3f1d48 |
295 | static const struct ssh2_cipher *cscipher = NULL; |
296 | static const struct ssh2_cipher *sccipher = NULL; |
57476f6b |
297 | static const struct ssh_mac *csmac = NULL; |
298 | static const struct ssh_mac *scmac = NULL; |
299 | static const struct ssh_compress *cscomp = NULL; |
300 | static const struct ssh_compress *sccomp = NULL; |
301 | static const struct ssh_kex *kex = NULL; |
e055a386 |
302 | static const struct ssh_signkey *hostkey = NULL; |
65a22376 |
303 | static unsigned char ssh2_session_id[20]; |
fa17a66e |
304 | int (*ssh_get_line)(const char *prompt, char *str, int maxlen, |
305 | int is_pw) = NULL; |
57476f6b |
306 | |
307 | static char *savedhost; |
308 | static int savedport; |
309 | static int ssh_send_ok; |
0965bee0 |
310 | static int ssh_echoing, ssh_editing; |
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311 | |
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312 | static tree234 *ssh_channels; /* indexed by local id */ |
57476f6b |
313 | static struct ssh_channel *mainchan; /* primary session channel */ |
314 | |
315 | static enum { |
3687d221 |
316 | SSH_STATE_PREPACKET, |
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317 | SSH_STATE_BEFORE_SIZE, |
318 | SSH_STATE_INTERMED, |
319 | SSH_STATE_SESSION, |
320 | SSH_STATE_CLOSED |
3687d221 |
321 | } ssh_state = SSH_STATE_PREPACKET; |
57476f6b |
322 | |
3687d221 |
323 | static int size_needed = FALSE, eof_needed = FALSE; |
57476f6b |
324 | |
325 | static struct Packet pktin = { 0, 0, NULL, NULL, 0 }; |
326 | static struct Packet pktout = { 0, 0, NULL, NULL, 0 }; |
b185170a |
327 | static unsigned char *deferred_send_data = NULL; |
328 | static int deferred_len = 0, deferred_size = 0; |
57476f6b |
329 | |
330 | static int ssh_version; |
331 | static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt); |
332 | static void ssh1_protocol(unsigned char *in, int inlen, int ispkt); |
333 | static void ssh2_protocol(unsigned char *in, int inlen, int ispkt); |
334 | static void ssh_size(void); |
3687d221 |
335 | static void ssh_special (Telnet_Special); |
783415f8 |
336 | static void ssh2_try_send(struct ssh_channel *c); |
337 | static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len); |
57476f6b |
338 | |
339 | static int (*s_rdpkt)(unsigned char **data, int *datalen); |
340 | |
341 | static struct rdpkt1_state_tag { |
342 | long len, pad, biglen, to_read; |
343 | unsigned long realcrc, gotcrc; |
344 | unsigned char *p; |
345 | int i; |
346 | int chunk; |
347 | } rdpkt1_state; |
348 | |
960e736a |
349 | static struct rdpkt2_state_tag { |
350 | long len, pad, payload, packetlen, maclen; |
351 | int i; |
352 | int cipherblk; |
353 | unsigned long incoming_sequence; |
354 | } rdpkt2_state; |
355 | |
dacbd0e8 |
356 | static int ssh_channelcmp(void *av, void *bv) { |
357 | struct ssh_channel *a = (struct ssh_channel *)av; |
358 | struct ssh_channel *b = (struct ssh_channel *)bv; |
359 | if (a->localid < b->localid) return -1; |
360 | if (a->localid > b->localid) return +1; |
361 | return 0; |
362 | } |
363 | static int ssh_channelfind(void *av, void *bv) { |
d211621f |
364 | unsigned *a = (unsigned *)av; |
dacbd0e8 |
365 | struct ssh_channel *b = (struct ssh_channel *)bv; |
366 | if (*a < b->localid) return -1; |
367 | if (*a > b->localid) return +1; |
368 | return 0; |
369 | } |
370 | |
d2371c81 |
371 | static int alloc_channel_id(void) { |
260f3dec |
372 | const unsigned CHANNEL_NUMBER_OFFSET = 256; |
373 | unsigned low, high, mid; |
d2371c81 |
374 | int tsize; |
375 | struct ssh_channel *c; |
376 | |
377 | /* |
378 | * First-fit allocation of channel numbers: always pick the |
379 | * lowest unused one. To do this, binary-search using the |
380 | * counted B-tree to find the largest channel ID which is in a |
381 | * contiguous sequence from the beginning. (Precisely |
382 | * everything in that sequence must have ID equal to its tree |
383 | * index plus CHANNEL_NUMBER_OFFSET.) |
384 | */ |
385 | tsize = count234(ssh_channels); |
386 | |
387 | low = -1; high = tsize; |
388 | while (high - low > 1) { |
389 | mid = (high + low) / 2; |
390 | c = index234(ssh_channels, mid); |
391 | if (c->localid == mid + CHANNEL_NUMBER_OFFSET) |
392 | low = mid; /* this one is fine */ |
393 | else |
394 | high = mid; /* this one is past it */ |
395 | } |
396 | /* |
397 | * Now low points to either -1, or the tree index of the |
398 | * largest ID in the initial sequence. |
399 | */ |
400 | { |
401 | unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET; |
402 | assert(NULL == find234(ssh_channels, &i, ssh_channelfind)); |
403 | } |
404 | return low + 1 + CHANNEL_NUMBER_OFFSET; |
405 | } |
406 | |
374330e2 |
407 | static void c_write (char *buf, int len) { |
67779be7 |
408 | if ((flags & FLAG_STDERR)) { |
4017be6d |
409 | int i; |
410 | for (i = 0; i < len; i++) |
411 | if (buf[i] != '\r') |
412 | fputc(buf[i], stderr); |
fb09bf1c |
413 | return; |
414 | } |
fe50e814 |
415 | from_backend(1, buf, len); |
3bdaf79d |
416 | } |
417 | |
a209e957 |
418 | static void c_write_untrusted(char *buf, int len) { |
419 | int i; |
420 | for (i = 0; i < len; i++) { |
421 | if (buf[i] == '\n') |
422 | c_write("\r\n", 2); |
423 | else if ((buf[i] & 0x60) || (buf[i] == '\r')) |
424 | c_write(buf+i, 1); |
425 | } |
426 | } |
427 | |
1408a877 |
428 | static void c_write_str (char *buf) { |
429 | c_write(buf, strlen(buf)); |
430 | } |
431 | |
fb09bf1c |
432 | /* |
433 | * Collect incoming data in the incoming packet buffer. |
e5574168 |
434 | * Decipher and verify the packet when it is completely read. |
435 | * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets. |
fb09bf1c |
436 | * Update the *data and *datalen variables. |
437 | * Return the additional nr of bytes needed, or 0 when |
438 | * a complete packet is available. |
439 | */ |
e5574168 |
440 | static int ssh1_rdpkt(unsigned char **data, int *datalen) |
fb09bf1c |
441 | { |
57476f6b |
442 | struct rdpkt1_state_tag *st = &rdpkt1_state; |
374330e2 |
443 | |
444 | crBegin; |
374330e2 |
445 | |
fb09bf1c |
446 | next_packet: |
37508af4 |
447 | |
fb09bf1c |
448 | pktin.type = 0; |
449 | pktin.length = 0; |
374330e2 |
450 | |
57476f6b |
451 | for (st->i = st->len = 0; st->i < 4; st->i++) { |
fb09bf1c |
452 | while ((*datalen) == 0) |
57476f6b |
453 | crReturn(4-st->i); |
454 | st->len = (st->len << 8) + **data; |
fb09bf1c |
455 | (*data)++, (*datalen)--; |
456 | } |
374330e2 |
457 | |
fb09bf1c |
458 | #ifdef FWHACK |
57476f6b |
459 | if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */ |
460 | st->len = 0x300; /* big enough to carry to end */ |
fb09bf1c |
461 | } |
462 | #endif |
374330e2 |
463 | |
57476f6b |
464 | st->pad = 8 - (st->len % 8); |
465 | st->biglen = st->len + st->pad; |
466 | pktin.length = st->len - 5; |
fb09bf1c |
467 | |
57476f6b |
468 | if (pktin.maxlen < st->biglen) { |
469 | pktin.maxlen = st->biglen; |
dcbde236 |
470 | pktin.data = (pktin.data == NULL ? smalloc(st->biglen+APIEXTRA) : |
471 | srealloc(pktin.data, st->biglen+APIEXTRA)); |
fb09bf1c |
472 | if (!pktin.data) |
473 | fatalbox("Out of memory"); |
474 | } |
374330e2 |
475 | |
57476f6b |
476 | st->to_read = st->biglen; |
477 | st->p = pktin.data; |
478 | while (st->to_read > 0) { |
479 | st->chunk = st->to_read; |
fb09bf1c |
480 | while ((*datalen) == 0) |
57476f6b |
481 | crReturn(st->to_read); |
482 | if (st->chunk > (*datalen)) |
483 | st->chunk = (*datalen); |
484 | memcpy(st->p, *data, st->chunk); |
485 | *data += st->chunk; |
486 | *datalen -= st->chunk; |
487 | st->p += st->chunk; |
488 | st->to_read -= st->chunk; |
fb09bf1c |
489 | } |
374330e2 |
490 | |
fb09bf1c |
491 | if (cipher) |
57476f6b |
492 | cipher->decrypt(pktin.data, st->biglen); |
765c4200 |
493 | #ifdef DUMP_PACKETS |
494 | debug(("Got packet len=%d pad=%d\n", st->len, st->pad)); |
495 | dmemdump(pktin.data, st->biglen); |
698a5108 |
496 | #endif |
374330e2 |
497 | |
57476f6b |
498 | st->realcrc = crc32(pktin.data, st->biglen-4); |
499 | st->gotcrc = GET_32BIT(pktin.data+st->biglen-4); |
500 | if (st->gotcrc != st->realcrc) { |
8d5de777 |
501 | bombout(("Incorrect CRC received on packet")); |
502 | crReturn(0); |
fb09bf1c |
503 | } |
572f871e |
504 | |
4ba9b64b |
505 | pktin.body = pktin.data + st->pad + 1; |
506 | |
507 | if (ssh1_compressing) { |
508 | unsigned char *decompblk; |
509 | int decomplen; |
765c4200 |
510 | #ifdef DUMP_PACKETS |
511 | debug(("Packet payload pre-decompression:\n")); |
512 | dmemdump(pktin.body-1, pktin.length+1); |
4ba9b64b |
513 | #endif |
514 | zlib_decompress_block(pktin.body-1, pktin.length+1, |
515 | &decompblk, &decomplen); |
516 | |
517 | if (pktin.maxlen < st->pad + decomplen) { |
518 | pktin.maxlen = st->pad + decomplen; |
dcbde236 |
519 | pktin.data = srealloc(pktin.data, pktin.maxlen+APIEXTRA); |
58298665 |
520 | pktin.body = pktin.data + st->pad + 1; |
4ba9b64b |
521 | if (!pktin.data) |
522 | fatalbox("Out of memory"); |
523 | } |
524 | |
525 | memcpy(pktin.body-1, decompblk, decomplen); |
dcbde236 |
526 | sfree(decompblk); |
4ba9b64b |
527 | pktin.length = decomplen-1; |
765c4200 |
528 | #ifdef DUMP_PACKETS |
529 | debug(("Packet payload post-decompression:\n")); |
530 | dmemdump(pktin.body-1, pktin.length+1); |
4ba9b64b |
531 | #endif |
532 | } |
533 | |
e5574168 |
534 | if (pktin.type == SSH1_SMSG_STDOUT_DATA || |
535 | pktin.type == SSH1_SMSG_STDERR_DATA || |
536 | pktin.type == SSH1_MSG_DEBUG || |
18515c51 |
537 | pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE || |
538 | pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) { |
fb09bf1c |
539 | long strlen = GET_32BIT(pktin.body); |
8d5de777 |
540 | if (strlen + 4 != pktin.length) { |
541 | bombout(("Received data packet with bogus string length")); |
542 | crReturn(0); |
543 | } |
fb09bf1c |
544 | } |
545 | |
4ba9b64b |
546 | pktin.type = pktin.body[-1]; |
547 | |
e5574168 |
548 | if (pktin.type == SSH1_MSG_DEBUG) { |
fb09bf1c |
549 | /* log debug message */ |
550 | char buf[80]; |
551 | int strlen = GET_32BIT(pktin.body); |
552 | strcpy(buf, "Remote: "); |
553 | if (strlen > 70) strlen = 70; |
554 | memcpy(buf+8, pktin.body+4, strlen); |
555 | buf[8+strlen] = '\0'; |
556 | logevent(buf); |
557 | goto next_packet; |
e5574168 |
558 | } else if (pktin.type == SSH1_MSG_IGNORE) { |
fb09bf1c |
559 | /* do nothing */ |
560 | goto next_packet; |
561 | } |
562 | |
38c4a8da |
563 | if (pktin.type == SSH1_MSG_DISCONNECT) { |
564 | /* log reason code in disconnect message */ |
565 | char buf[256]; |
260f3dec |
566 | unsigned msglen = GET_32BIT(pktin.body); |
567 | unsigned nowlen; |
38c4a8da |
568 | strcpy(buf, "Remote sent disconnect: "); |
569 | nowlen = strlen(buf); |
570 | if (msglen > sizeof(buf)-nowlen-1) |
571 | msglen = sizeof(buf)-nowlen-1; |
572 | memcpy(buf+nowlen, pktin.body+4, msglen); |
573 | buf[nowlen+msglen] = '\0'; |
574 | logevent(buf); |
575 | } |
576 | |
fb09bf1c |
577 | crFinish(0); |
578 | } |
579 | |
e5574168 |
580 | static int ssh2_rdpkt(unsigned char **data, int *datalen) |
581 | { |
960e736a |
582 | struct rdpkt2_state_tag *st = &rdpkt2_state; |
e5574168 |
583 | |
584 | crBegin; |
585 | |
586 | next_packet: |
e5574168 |
587 | pktin.type = 0; |
588 | pktin.length = 0; |
960e736a |
589 | if (sccipher) |
590 | st->cipherblk = sccipher->blksize; |
e5574168 |
591 | else |
960e736a |
592 | st->cipherblk = 8; |
593 | if (st->cipherblk < 8) |
594 | st->cipherblk = 8; |
595 | |
596 | if (pktin.maxlen < st->cipherblk) { |
597 | pktin.maxlen = st->cipherblk; |
dcbde236 |
598 | pktin.data = (pktin.data == NULL ? smalloc(st->cipherblk+APIEXTRA) : |
599 | srealloc(pktin.data, st->cipherblk+APIEXTRA)); |
e5574168 |
600 | if (!pktin.data) |
601 | fatalbox("Out of memory"); |
602 | } |
603 | |
604 | /* |
605 | * Acquire and decrypt the first block of the packet. This will |
606 | * contain the length and padding details. |
607 | */ |
960e736a |
608 | for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) { |
e5574168 |
609 | while ((*datalen) == 0) |
960e736a |
610 | crReturn(st->cipherblk-st->i); |
611 | pktin.data[st->i] = *(*data)++; |
e5574168 |
612 | (*datalen)--; |
613 | } |
614 | #ifdef FWHACK |
615 | if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */ |
616 | /* FIXME */ |
617 | } |
618 | #endif |
619 | if (sccipher) |
960e736a |
620 | sccipher->decrypt(pktin.data, st->cipherblk); |
e5574168 |
621 | |
622 | /* |
623 | * Now get the length and padding figures. |
624 | */ |
960e736a |
625 | st->len = GET_32BIT(pktin.data); |
626 | st->pad = pktin.data[4]; |
e5574168 |
627 | |
628 | /* |
629 | * This enables us to deduce the payload length. |
630 | */ |
960e736a |
631 | st->payload = st->len - st->pad - 1; |
e5574168 |
632 | |
960e736a |
633 | pktin.length = st->payload + 5; |
e5574168 |
634 | |
635 | /* |
636 | * So now we can work out the total packet length. |
637 | */ |
960e736a |
638 | st->packetlen = st->len + 4; |
639 | st->maclen = scmac ? scmac->len : 0; |
e5574168 |
640 | |
641 | /* |
642 | * Adjust memory allocation if packet is too big. |
643 | */ |
960e736a |
644 | if (pktin.maxlen < st->packetlen+st->maclen) { |
645 | pktin.maxlen = st->packetlen+st->maclen; |
dcbde236 |
646 | pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) : |
647 | srealloc(pktin.data, pktin.maxlen+APIEXTRA)); |
e5574168 |
648 | if (!pktin.data) |
649 | fatalbox("Out of memory"); |
650 | } |
651 | |
652 | /* |
653 | * Read and decrypt the remainder of the packet. |
654 | */ |
960e736a |
655 | for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; st->i++) { |
e5574168 |
656 | while ((*datalen) == 0) |
960e736a |
657 | crReturn(st->packetlen + st->maclen - st->i); |
658 | pktin.data[st->i] = *(*data)++; |
e5574168 |
659 | (*datalen)--; |
660 | } |
661 | /* Decrypt everything _except_ the MAC. */ |
662 | if (sccipher) |
960e736a |
663 | sccipher->decrypt(pktin.data + st->cipherblk, |
664 | st->packetlen - st->cipherblk); |
e5574168 |
665 | |
765c4200 |
666 | #ifdef DUMP_PACKETS |
667 | debug(("Got packet len=%d pad=%d\n", st->len, st->pad)); |
668 | dmemdump(pktin.data, st->packetlen); |
7cca0d81 |
669 | #endif |
d39f364a |
670 | |
e5574168 |
671 | /* |
672 | * Check the MAC. |
673 | */ |
960e736a |
674 | if (scmac && !scmac->verify(pktin.data, st->len+4, st->incoming_sequence)) { |
8d5de777 |
675 | bombout(("Incorrect MAC received on packet")); |
676 | crReturn(0); |
677 | } |
960e736a |
678 | st->incoming_sequence++; /* whether or not we MACed */ |
e5574168 |
679 | |
4ba9b64b |
680 | /* |
681 | * Decompress packet payload. |
682 | */ |
683 | { |
684 | unsigned char *newpayload; |
685 | int newlen; |
686 | if (sccomp && sccomp->decompress(pktin.data+5, pktin.length-5, |
687 | &newpayload, &newlen)) { |
688 | if (pktin.maxlen < newlen+5) { |
689 | pktin.maxlen = newlen+5; |
dcbde236 |
690 | pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) : |
691 | srealloc(pktin.data, pktin.maxlen+APIEXTRA)); |
4ba9b64b |
692 | if (!pktin.data) |
693 | fatalbox("Out of memory"); |
694 | } |
695 | pktin.length = 5 + newlen; |
696 | memcpy(pktin.data+5, newpayload, newlen); |
765c4200 |
697 | #ifdef DUMP_PACKETS |
698 | debug(("Post-decompression payload:\n")); |
699 | dmemdump(pktin.data+5, newlen); |
4ba9b64b |
700 | #endif |
701 | |
dcbde236 |
702 | sfree(newpayload); |
4ba9b64b |
703 | } |
704 | } |
705 | |
e5574168 |
706 | pktin.savedpos = 6; |
707 | pktin.type = pktin.data[5]; |
e5574168 |
708 | |
7cca0d81 |
709 | if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG) |
710 | goto next_packet; /* FIXME: print DEBUG message */ |
e5574168 |
711 | |
38c4a8da |
712 | if (pktin.type == SSH2_MSG_DISCONNECT) { |
713 | /* log reason code in disconnect message */ |
714 | char buf[256]; |
715 | int reason = GET_32BIT(pktin.data+6); |
260f3dec |
716 | unsigned msglen = GET_32BIT(pktin.data+10); |
717 | unsigned nowlen; |
38c4a8da |
718 | if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) { |
719 | sprintf(buf, "Received disconnect message (%s)", |
720 | ssh2_disconnect_reasons[reason]); |
721 | } else { |
722 | sprintf(buf, "Received disconnect message (unknown type %d)", reason); |
723 | } |
724 | logevent(buf); |
725 | strcpy(buf, "Disconnection message text: "); |
726 | nowlen = strlen(buf); |
727 | if (msglen > sizeof(buf)-nowlen-1) |
728 | msglen = sizeof(buf)-nowlen-1; |
729 | memcpy(buf+nowlen, pktin.data+14, msglen); |
730 | buf[nowlen+msglen] = '\0'; |
731 | logevent(buf); |
732 | } |
733 | |
e5574168 |
734 | crFinish(0); |
735 | } |
736 | |
4ba9b64b |
737 | static void ssh1_pktout_size(int len) { |
374330e2 |
738 | int pad, biglen; |
739 | |
740 | len += 5; /* type and CRC */ |
741 | pad = 8 - (len%8); |
742 | biglen = len + pad; |
743 | |
744 | pktout.length = len-5; |
745 | if (pktout.maxlen < biglen) { |
746 | pktout.maxlen = biglen; |
8f203108 |
747 | #ifdef MSCRYPTOAPI |
fb09bf1c |
748 | /* Allocate enough buffer space for extra block |
8f203108 |
749 | * for MS CryptEncrypt() */ |
dcbde236 |
750 | pktout.data = (pktout.data == NULL ? smalloc(biglen+12) : |
751 | srealloc(pktout.data, biglen+12)); |
8f203108 |
752 | #else |
dcbde236 |
753 | pktout.data = (pktout.data == NULL ? smalloc(biglen+4) : |
754 | srealloc(pktout.data, biglen+4)); |
8f203108 |
755 | #endif |
374330e2 |
756 | if (!pktout.data) |
757 | fatalbox("Out of memory"); |
758 | } |
4ba9b64b |
759 | pktout.body = pktout.data+4+pad+1; |
760 | } |
374330e2 |
761 | |
4ba9b64b |
762 | static void s_wrpkt_start(int type, int len) { |
763 | ssh1_pktout_size(len); |
374330e2 |
764 | pktout.type = type; |
374330e2 |
765 | } |
766 | |
39065bed |
767 | static int s_wrpkt_prepare(void) { |
374330e2 |
768 | int pad, len, biglen, i; |
769 | unsigned long crc; |
770 | |
4ba9b64b |
771 | pktout.body[-1] = pktout.type; |
772 | |
765c4200 |
773 | #ifdef DUMP_PACKETS |
7d503c31 |
774 | debug(("Packet payload pre-compression:\n")); |
765c4200 |
775 | dmemdump(pktout.body-1, pktout.length+1); |
7d503c31 |
776 | #endif |
777 | |
4ba9b64b |
778 | if (ssh1_compressing) { |
779 | unsigned char *compblk; |
780 | int complen; |
4ba9b64b |
781 | zlib_compress_block(pktout.body-1, pktout.length+1, |
782 | &compblk, &complen); |
783 | ssh1_pktout_size(complen-1); |
784 | memcpy(pktout.body-1, compblk, complen); |
dcbde236 |
785 | sfree(compblk); |
765c4200 |
786 | #ifdef DUMP_PACKETS |
4ba9b64b |
787 | debug(("Packet payload post-compression:\n")); |
765c4200 |
788 | dmemdump(pktout.body-1, pktout.length+1); |
4ba9b64b |
789 | #endif |
790 | } |
791 | |
374330e2 |
792 | len = pktout.length + 5; /* type and CRC */ |
793 | pad = 8 - (len%8); |
794 | biglen = len + pad; |
795 | |
374330e2 |
796 | for (i=0; i<pad; i++) |
797 | pktout.data[i+4] = random_byte(); |
798 | crc = crc32(pktout.data+4, biglen-4); |
fb09bf1c |
799 | PUT_32BIT(pktout.data+biglen, crc); |
800 | PUT_32BIT(pktout.data, len); |
374330e2 |
801 | |
765c4200 |
802 | #ifdef DUMP_PACKETS |
803 | debug(("Sending packet len=%d\n", biglen+4)); |
804 | dmemdump(pktout.data, biglen+4); |
698a5108 |
805 | #endif |
374330e2 |
806 | if (cipher) |
807 | cipher->encrypt(pktout.data+4, biglen); |
808 | |
39065bed |
809 | return biglen+4; |
810 | } |
811 | |
812 | static void s_wrpkt(void) { |
813 | int len; |
814 | len = s_wrpkt_prepare(); |
815 | sk_write(s, pktout.data, len); |
816 | } |
817 | |
818 | static void s_wrpkt_defer(void) { |
819 | int len; |
820 | len = s_wrpkt_prepare(); |
821 | if (deferred_len + len > deferred_size) { |
822 | deferred_size = deferred_len + len + 128; |
823 | deferred_send_data = srealloc(deferred_send_data, deferred_size); |
824 | } |
825 | memcpy(deferred_send_data+deferred_len, pktout.data, len); |
826 | deferred_len += len; |
374330e2 |
827 | } |
828 | |
fb09bf1c |
829 | /* |
39065bed |
830 | * Construct a packet with the specified contents. |
fb09bf1c |
831 | */ |
39065bed |
832 | static void construct_packet(int pkttype, va_list ap1, va_list ap2) |
fb09bf1c |
833 | { |
fb09bf1c |
834 | unsigned char *p, *argp, argchar; |
835 | unsigned long argint; |
836 | int pktlen, argtype, arglen; |
7cca0d81 |
837 | Bignum bn; |
fb09bf1c |
838 | |
839 | pktlen = 0; |
39065bed |
840 | while ((argtype = va_arg(ap1, int)) != PKT_END) { |
fb09bf1c |
841 | switch (argtype) { |
842 | case PKT_INT: |
39065bed |
843 | (void) va_arg(ap1, int); |
fb09bf1c |
844 | pktlen += 4; |
845 | break; |
846 | case PKT_CHAR: |
39065bed |
847 | (void) va_arg(ap1, char); |
fb09bf1c |
848 | pktlen++; |
849 | break; |
850 | case PKT_DATA: |
39065bed |
851 | (void) va_arg(ap1, unsigned char *); |
852 | arglen = va_arg(ap1, int); |
fb09bf1c |
853 | pktlen += arglen; |
854 | break; |
855 | case PKT_STR: |
39065bed |
856 | argp = va_arg(ap1, unsigned char *); |
fb09bf1c |
857 | arglen = strlen(argp); |
858 | pktlen += 4 + arglen; |
859 | break; |
7cca0d81 |
860 | case PKT_BIGNUM: |
39065bed |
861 | bn = va_arg(ap1, Bignum); |
5c58ad2d |
862 | pktlen += ssh1_bignum_length(bn); |
7cca0d81 |
863 | break; |
fb09bf1c |
864 | default: |
865 | assert(0); |
866 | } |
867 | } |
fb09bf1c |
868 | |
869 | s_wrpkt_start(pkttype, pktlen); |
870 | p = pktout.body; |
871 | |
39065bed |
872 | while ((argtype = va_arg(ap2, int)) != PKT_END) { |
fb09bf1c |
873 | switch (argtype) { |
874 | case PKT_INT: |
39065bed |
875 | argint = va_arg(ap2, int); |
fb09bf1c |
876 | PUT_32BIT(p, argint); |
877 | p += 4; |
878 | break; |
879 | case PKT_CHAR: |
39065bed |
880 | argchar = va_arg(ap2, unsigned char); |
fb09bf1c |
881 | *p = argchar; |
882 | p++; |
883 | break; |
884 | case PKT_DATA: |
39065bed |
885 | argp = va_arg(ap2, unsigned char *); |
886 | arglen = va_arg(ap2, int); |
fb09bf1c |
887 | memcpy(p, argp, arglen); |
888 | p += arglen; |
889 | break; |
890 | case PKT_STR: |
39065bed |
891 | argp = va_arg(ap2, unsigned char *); |
fb09bf1c |
892 | arglen = strlen(argp); |
893 | PUT_32BIT(p, arglen); |
894 | memcpy(p + 4, argp, arglen); |
895 | p += 4 + arglen; |
896 | break; |
7cca0d81 |
897 | case PKT_BIGNUM: |
39065bed |
898 | bn = va_arg(ap2, Bignum); |
5c58ad2d |
899 | p += ssh1_write_bignum(p, bn); |
7cca0d81 |
900 | break; |
fb09bf1c |
901 | } |
902 | } |
39065bed |
903 | } |
fb09bf1c |
904 | |
39065bed |
905 | static void send_packet(int pkttype, ...) { |
906 | va_list ap1, ap2; |
907 | va_start(ap1, pkttype); |
908 | va_start(ap2, pkttype); |
909 | construct_packet(pkttype, ap1, ap2); |
fb09bf1c |
910 | s_wrpkt(); |
911 | } |
912 | |
39065bed |
913 | static void defer_packet(int pkttype, ...) { |
914 | va_list ap1, ap2; |
915 | va_start(ap1, pkttype); |
916 | va_start(ap2, pkttype); |
917 | construct_packet(pkttype, ap1, ap2); |
918 | s_wrpkt_defer(); |
919 | } |
920 | |
9697bfd2 |
921 | static int ssh_versioncmp(char *a, char *b) { |
922 | char *ae, *be; |
923 | unsigned long av, bv; |
924 | |
43aa02a7 |
925 | av = strtoul(a, &ae, 10); |
926 | bv = strtoul(b, &be, 10); |
9697bfd2 |
927 | if (av != bv) return (av < bv ? -1 : +1); |
928 | if (*ae == '.') ae++; |
929 | if (*be == '.') be++; |
43aa02a7 |
930 | av = strtoul(ae, &ae, 10); |
931 | bv = strtoul(be, &be, 10); |
9697bfd2 |
932 | if (av != bv) return (av < bv ? -1 : +1); |
933 | return 0; |
934 | } |
935 | |
e5574168 |
936 | |
937 | /* |
a92dd380 |
938 | * Utility routines for putting an SSH-protocol `string' and |
939 | * `uint32' into a SHA state. |
e5574168 |
940 | */ |
941 | #include <stdio.h> |
75cab814 |
942 | static void sha_string(SHA_State *s, void *str, int len) { |
e5574168 |
943 | unsigned char lenblk[4]; |
e5574168 |
944 | PUT_32BIT(lenblk, len); |
e5574168 |
945 | SHA_Bytes(s, lenblk, 4); |
e5574168 |
946 | SHA_Bytes(s, str, len); |
947 | } |
948 | |
a92dd380 |
949 | static void sha_uint32(SHA_State *s, unsigned i) { |
950 | unsigned char intblk[4]; |
951 | PUT_32BIT(intblk, i); |
952 | SHA_Bytes(s, intblk, 4); |
953 | } |
954 | |
7cca0d81 |
955 | /* |
956 | * SSH2 packet construction functions. |
957 | */ |
783415f8 |
958 | static void ssh2_pkt_ensure(int length) { |
959 | if (pktout.maxlen < length) { |
960 | pktout.maxlen = length + 256; |
dcbde236 |
961 | pktout.data = (pktout.data == NULL ? smalloc(pktout.maxlen+APIEXTRA) : |
962 | srealloc(pktout.data, pktout.maxlen+APIEXTRA)); |
7cca0d81 |
963 | if (!pktout.data) |
964 | fatalbox("Out of memory"); |
965 | } |
783415f8 |
966 | } |
967 | static void ssh2_pkt_adddata(void *data, int len) { |
968 | pktout.length += len; |
969 | ssh2_pkt_ensure(pktout.length); |
7cca0d81 |
970 | memcpy(pktout.data+pktout.length-len, data, len); |
971 | } |
75cab814 |
972 | static void ssh2_pkt_addbyte(unsigned char byte) { |
7cca0d81 |
973 | ssh2_pkt_adddata(&byte, 1); |
974 | } |
75cab814 |
975 | static void ssh2_pkt_init(int pkt_type) { |
7cca0d81 |
976 | pktout.length = 5; |
977 | ssh2_pkt_addbyte((unsigned char)pkt_type); |
978 | } |
75cab814 |
979 | static void ssh2_pkt_addbool(unsigned char value) { |
7cca0d81 |
980 | ssh2_pkt_adddata(&value, 1); |
981 | } |
75cab814 |
982 | static void ssh2_pkt_adduint32(unsigned long value) { |
7cca0d81 |
983 | unsigned char x[4]; |
984 | PUT_32BIT(x, value); |
985 | ssh2_pkt_adddata(x, 4); |
986 | } |
75cab814 |
987 | static void ssh2_pkt_addstring_start(void) { |
7cca0d81 |
988 | ssh2_pkt_adduint32(0); |
989 | pktout.savedpos = pktout.length; |
990 | } |
75cab814 |
991 | static void ssh2_pkt_addstring_str(char *data) { |
7cca0d81 |
992 | ssh2_pkt_adddata(data, strlen(data)); |
993 | PUT_32BIT(pktout.data + pktout.savedpos - 4, |
994 | pktout.length - pktout.savedpos); |
995 | } |
75cab814 |
996 | static void ssh2_pkt_addstring_data(char *data, int len) { |
7cca0d81 |
997 | ssh2_pkt_adddata(data, len); |
998 | PUT_32BIT(pktout.data + pktout.savedpos - 4, |
999 | pktout.length - pktout.savedpos); |
1000 | } |
75cab814 |
1001 | static void ssh2_pkt_addstring(char *data) { |
7cca0d81 |
1002 | ssh2_pkt_addstring_start(); |
1003 | ssh2_pkt_addstring_str(data); |
1004 | } |
75cab814 |
1005 | static char *ssh2_mpint_fmt(Bignum b, int *len) { |
7cca0d81 |
1006 | unsigned char *p; |
ddecd643 |
1007 | int i, n = (bignum_bitcount(b)+7)/8; |
3709bfe9 |
1008 | p = smalloc(n + 1); |
7cca0d81 |
1009 | if (!p) |
1010 | fatalbox("out of memory"); |
1011 | p[0] = 0; |
3709bfe9 |
1012 | for (i = 1; i <= n; i++) |
1013 | p[i] = bignum_byte(b, n-i); |
7cca0d81 |
1014 | i = 0; |
3709bfe9 |
1015 | while (i <= n && p[i] == 0 && (p[i+1] & 0x80) == 0) |
7cca0d81 |
1016 | i++; |
3709bfe9 |
1017 | memmove(p, p+i, n+1-i); |
1018 | *len = n+1-i; |
7cca0d81 |
1019 | return p; |
1020 | } |
75cab814 |
1021 | static void ssh2_pkt_addmp(Bignum b) { |
7cca0d81 |
1022 | unsigned char *p; |
1023 | int len; |
1024 | p = ssh2_mpint_fmt(b, &len); |
1025 | ssh2_pkt_addstring_start(); |
1026 | ssh2_pkt_addstring_data(p, len); |
dcbde236 |
1027 | sfree(p); |
7cca0d81 |
1028 | } |
b185170a |
1029 | |
1030 | /* |
1031 | * Construct an SSH2 final-form packet: compress it, encrypt it, |
1032 | * put the MAC on it. Final packet, ready to be sent, is stored in |
1033 | * pktout.data. Total length is returned. |
1034 | */ |
1035 | static int ssh2_pkt_construct(void) { |
7cca0d81 |
1036 | int cipherblk, maclen, padding, i; |
1037 | static unsigned long outgoing_sequence = 0; |
1038 | |
1039 | /* |
4ba9b64b |
1040 | * Compress packet payload. |
1041 | */ |
765c4200 |
1042 | #ifdef DUMP_PACKETS |
1043 | debug(("Pre-compression payload:\n")); |
1044 | dmemdump(pktout.data+5, pktout.length-5); |
4ba9b64b |
1045 | #endif |
1046 | { |
1047 | unsigned char *newpayload; |
1048 | int newlen; |
1049 | if (cscomp && cscomp->compress(pktout.data+5, pktout.length-5, |
1050 | &newpayload, &newlen)) { |
1051 | pktout.length = 5; |
1052 | ssh2_pkt_adddata(newpayload, newlen); |
dcbde236 |
1053 | sfree(newpayload); |
4ba9b64b |
1054 | } |
1055 | } |
1056 | |
1057 | /* |
7cca0d81 |
1058 | * Add padding. At least four bytes, and must also bring total |
1059 | * length (minus MAC) up to a multiple of the block size. |
1060 | */ |
8479e33c |
1061 | cipherblk = cscipher ? cscipher->blksize : 8; /* block size */ |
7cca0d81 |
1062 | cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */ |
1063 | padding = 4; |
1064 | padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk; |
783415f8 |
1065 | maclen = csmac ? csmac->len : 0; |
1066 | ssh2_pkt_ensure(pktout.length + padding + maclen); |
7cca0d81 |
1067 | pktout.data[4] = padding; |
1068 | for (i = 0; i < padding; i++) |
1069 | pktout.data[pktout.length + i] = random_byte(); |
1070 | PUT_32BIT(pktout.data, pktout.length + padding - 4); |
1071 | if (csmac) |
1072 | csmac->generate(pktout.data, pktout.length + padding, |
1073 | outgoing_sequence); |
1074 | outgoing_sequence++; /* whether or not we MACed */ |
1075 | |
765c4200 |
1076 | #ifdef DUMP_PACKETS |
1077 | debug(("Sending packet len=%d\n", pktout.length+padding)); |
1078 | dmemdump(pktout.data, pktout.length+padding); |
7cca0d81 |
1079 | #endif |
1080 | |
1081 | if (cscipher) |
1082 | cscipher->encrypt(pktout.data, pktout.length + padding); |
7cca0d81 |
1083 | |
b185170a |
1084 | /* Ready-to-send packet starts at pktout.data. We return length. */ |
1085 | return pktout.length + padding + maclen; |
1086 | } |
1087 | |
1088 | /* |
1089 | * Construct and send an SSH2 packet immediately. |
1090 | */ |
1091 | static void ssh2_pkt_send(void) { |
1092 | int len = ssh2_pkt_construct(); |
1093 | sk_write(s, pktout.data, len); |
1094 | } |
1095 | |
1096 | /* |
1097 | * Construct an SSH2 packet and add it to a deferred data block. |
1098 | * Useful for sending multiple packets in a single sk_write() call, |
1099 | * to prevent a traffic-analysing listener from being able to work |
1100 | * out the length of any particular packet (such as the password |
1101 | * packet). |
1102 | * |
1103 | * Note that because SSH2 sequence-numbers its packets, this can |
1104 | * NOT be used as an m4-style `defer' allowing packets to be |
1105 | * constructed in one order and sent in another. |
1106 | */ |
1107 | static void ssh2_pkt_defer(void) { |
1108 | int len = ssh2_pkt_construct(); |
1109 | if (deferred_len + len > deferred_size) { |
1110 | deferred_size = deferred_len + len + 128; |
1111 | deferred_send_data = srealloc(deferred_send_data, deferred_size); |
1112 | } |
1113 | memcpy(deferred_send_data+deferred_len, pktout.data, len); |
1114 | deferred_len += len; |
1115 | } |
1116 | |
1117 | /* |
1118 | * Send the whole deferred data block constructed by |
39065bed |
1119 | * ssh2_pkt_defer() or SSH1's defer_packet(). |
b185170a |
1120 | */ |
39065bed |
1121 | static void ssh_pkt_defersend(void) { |
b185170a |
1122 | sk_write(s, deferred_send_data, deferred_len); |
1123 | deferred_len = deferred_size = 0; |
1124 | sfree(deferred_send_data); |
1125 | deferred_send_data = NULL; |
7cca0d81 |
1126 | } |
1127 | |
1128 | #if 0 |
1129 | void bndebug(char *string, Bignum b) { |
1130 | unsigned char *p; |
1131 | int i, len; |
1132 | p = ssh2_mpint_fmt(b, &len); |
1133 | debug(("%s", string)); |
1134 | for (i = 0; i < len; i++) |
1135 | debug((" %02x", p[i])); |
765c4200 |
1136 | debug(("\n")); |
dcbde236 |
1137 | sfree(p); |
7cca0d81 |
1138 | } |
1139 | #endif |
1140 | |
75cab814 |
1141 | static void sha_mpint(SHA_State *s, Bignum b) { |
7cca0d81 |
1142 | unsigned char *p; |
1143 | int len; |
1144 | p = ssh2_mpint_fmt(b, &len); |
1145 | sha_string(s, p, len); |
dcbde236 |
1146 | sfree(p); |
7cca0d81 |
1147 | } |
1148 | |
1149 | /* |
1150 | * SSH2 packet decode functions. |
1151 | */ |
75cab814 |
1152 | static unsigned long ssh2_pkt_getuint32(void) { |
7cca0d81 |
1153 | unsigned long value; |
1154 | if (pktin.length - pktin.savedpos < 4) |
1155 | return 0; /* arrgh, no way to decline (FIXME?) */ |
1156 | value = GET_32BIT(pktin.data+pktin.savedpos); |
1157 | pktin.savedpos += 4; |
1158 | return value; |
1159 | } |
65a22376 |
1160 | static int ssh2_pkt_getbool(void) { |
1161 | unsigned long value; |
1162 | if (pktin.length - pktin.savedpos < 1) |
1163 | return 0; /* arrgh, no way to decline (FIXME?) */ |
1164 | value = pktin.data[pktin.savedpos] != 0; |
1165 | pktin.savedpos++; |
1166 | return value; |
1167 | } |
75cab814 |
1168 | static void ssh2_pkt_getstring(char **p, int *length) { |
7cca0d81 |
1169 | *p = NULL; |
1170 | if (pktin.length - pktin.savedpos < 4) |
1171 | return; |
1172 | *length = GET_32BIT(pktin.data+pktin.savedpos); |
1173 | pktin.savedpos += 4; |
1174 | if (pktin.length - pktin.savedpos < *length) |
1175 | return; |
1176 | *p = pktin.data+pktin.savedpos; |
1177 | pktin.savedpos += *length; |
1178 | } |
75cab814 |
1179 | static Bignum ssh2_pkt_getmp(void) { |
7cca0d81 |
1180 | char *p; |
3709bfe9 |
1181 | int length; |
7cca0d81 |
1182 | Bignum b; |
1183 | |
1184 | ssh2_pkt_getstring(&p, &length); |
1185 | if (!p) |
1186 | return NULL; |
8d5de777 |
1187 | if (p[0] & 0x80) { |
1188 | bombout(("internal error: Can't handle negative mpints")); |
1189 | return NULL; |
1190 | } |
3709bfe9 |
1191 | b = bignum_from_bytes(p, length); |
7cca0d81 |
1192 | return b; |
1193 | } |
1194 | |
7d503c31 |
1195 | /* |
1196 | * Examine the remote side's version string and compare it against |
1197 | * a list of known buggy implementations. |
1198 | */ |
1199 | static void ssh_detect_bugs(char *vstring) { |
1200 | char *imp; /* pointer to implementation part */ |
1201 | imp = vstring; |
1202 | imp += strcspn(imp, "-"); |
620f0caf |
1203 | if (*imp) imp++; |
7d503c31 |
1204 | imp += strcspn(imp, "-"); |
620f0caf |
1205 | if (*imp) imp++; |
7d503c31 |
1206 | |
1207 | ssh_remote_bugs = 0; |
1208 | |
1209 | if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") || |
1210 | !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") || |
1211 | !strcmp(imp, "1.2.22")) { |
1212 | /* |
1213 | * These versions don't support SSH1_MSG_IGNORE, so we have |
1214 | * to use a different defence against password length |
1215 | * sniffing. |
1216 | */ |
1217 | ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE; |
1218 | logevent("We believe remote version has SSH1 ignore bug"); |
1219 | } |
1220 | |
1221 | if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) || |
1222 | !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) || |
1223 | !strncmp(imp, "2.1 ", 4)) { |
1224 | /* |
1225 | * These versions have the HMAC bug. |
1226 | */ |
1227 | ssh_remote_bugs |= BUG_SSH2_HMAC; |
1228 | logevent("We believe remote version has SSH2 HMAC bug"); |
1229 | } |
1230 | } |
1231 | |
8df7a775 |
1232 | static int do_ssh_init(unsigned char c) { |
50526e47 |
1233 | static char vslen; |
8df7a775 |
1234 | static char version[10]; |
50526e47 |
1235 | static char *vstring; |
1236 | static int vstrsize; |
1237 | static char *vlog; |
8df7a775 |
1238 | static int i; |
374330e2 |
1239 | |
8df7a775 |
1240 | crBegin; |
1241 | |
1242 | /* Search for the string "SSH-" in the input. */ |
374330e2 |
1243 | i = 0; |
8df7a775 |
1244 | while (1) { |
1245 | static const int transS[] = { 1, 2, 2, 1 }; |
1246 | static const int transH[] = { 0, 0, 3, 0 }; |
1247 | static const int transminus[] = { 0, 0, 0, -1 }; |
1248 | if (c == 'S') i = transS[i]; |
1249 | else if (c == 'H') i = transH[i]; |
1250 | else if (c == '-') i = transminus[i]; |
374330e2 |
1251 | else i = 0; |
8df7a775 |
1252 | if (i < 0) |
1253 | break; |
1254 | crReturn(1); /* get another character */ |
374330e2 |
1255 | } |
8df7a775 |
1256 | |
50526e47 |
1257 | vstring = smalloc(16); |
1258 | vstrsize = 16; |
c5e9c988 |
1259 | strcpy(vstring, "SSH-"); |
50526e47 |
1260 | vslen = 4; |
374330e2 |
1261 | i = 0; |
1262 | while (1) { |
8df7a775 |
1263 | crReturn(1); /* get another char */ |
50526e47 |
1264 | if (vslen >= vstrsize-1) { |
1265 | vstrsize += 16; |
1266 | vstring = srealloc(vstring, vstrsize); |
1267 | } |
1268 | vstring[vslen++] = c; |
374330e2 |
1269 | if (i >= 0) { |
1270 | if (c == '-') { |
1271 | version[i] = '\0'; |
1272 | i = -1; |
1273 | } else if (i < sizeof(version)-1) |
1274 | version[i++] = c; |
1275 | } |
1276 | else if (c == '\n') |
1277 | break; |
1278 | } |
1279 | |
db7d555c |
1280 | ssh_agentfwd_enabled = FALSE; |
960e736a |
1281 | rdpkt2_state.incoming_sequence = 0; |
1282 | |
50526e47 |
1283 | vstring[vslen] = 0; |
9275ca8a |
1284 | vlog = smalloc(20 + vslen); |
c5e9c988 |
1285 | sprintf(vlog, "Server version: %s", vstring); |
7d503c31 |
1286 | ssh_detect_bugs(vstring); |
c5e9c988 |
1287 | vlog[strcspn(vlog, "\r\n")] = '\0'; |
1288 | logevent(vlog); |
9275ca8a |
1289 | sfree(vlog); |
c5e9c988 |
1290 | |
adf799dd |
1291 | /* |
1292 | * Server version "1.99" means we can choose whether we use v1 |
1293 | * or v2 protocol. Choice is based on cfg.sshprot. |
1294 | */ |
1295 | if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) { |
e5574168 |
1296 | /* |
1297 | * This is a v2 server. Begin v2 protocol. |
1298 | */ |
9275ca8a |
1299 | char verstring[80], vlog[100]; |
900a4ee6 |
1300 | sprintf(verstring, "SSH-2.0-%s", sshver); |
0db56f73 |
1301 | SHA_Init(&exhashbase); |
e5574168 |
1302 | /* |
1303 | * Hash our version string and their version string. |
1304 | */ |
0db56f73 |
1305 | sha_string(&exhashbase, verstring, strlen(verstring)); |
1306 | sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n")); |
e5574168 |
1307 | sprintf(vlog, "We claim version: %s", verstring); |
1308 | logevent(vlog); |
9275ca8a |
1309 | strcat(verstring, "\n"); |
e5574168 |
1310 | logevent("Using SSH protocol version 2"); |
9275ca8a |
1311 | sk_write(s, verstring, strlen(verstring)); |
e5574168 |
1312 | ssh_protocol = ssh2_protocol; |
6abbf9e3 |
1313 | ssh_version = 2; |
e5574168 |
1314 | s_rdpkt = ssh2_rdpkt; |
1315 | } else { |
1316 | /* |
1317 | * This is a v1 server. Begin v1 protocol. |
1318 | */ |
9275ca8a |
1319 | char verstring[80], vlog[100]; |
1320 | sprintf(verstring, "SSH-%s-%s", |
900a4ee6 |
1321 | (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"), |
1322 | sshver); |
9275ca8a |
1323 | sprintf(vlog, "We claim version: %s", verstring); |
e5574168 |
1324 | logevent(vlog); |
9275ca8a |
1325 | strcat(verstring, "\n"); |
e5574168 |
1326 | logevent("Using SSH protocol version 1"); |
9275ca8a |
1327 | sk_write(s, verstring, strlen(verstring)); |
e5574168 |
1328 | ssh_protocol = ssh1_protocol; |
6abbf9e3 |
1329 | ssh_version = 1; |
e5574168 |
1330 | s_rdpkt = ssh1_rdpkt; |
1331 | } |
3687d221 |
1332 | ssh_state = SSH_STATE_BEFORE_SIZE; |
8df7a775 |
1333 | |
50526e47 |
1334 | sfree(vstring); |
50526e47 |
1335 | |
8df7a775 |
1336 | crFinish(0); |
1337 | } |
1338 | |
1339 | static void ssh_gotdata(unsigned char *data, int datalen) |
1340 | { |
1341 | crBegin; |
1342 | |
1343 | /* |
1344 | * To begin with, feed the characters one by one to the |
1345 | * protocol initialisation / selection function do_ssh_init(). |
1346 | * When that returns 0, we're done with the initial greeting |
1347 | * exchange and can move on to packet discipline. |
1348 | */ |
1349 | while (1) { |
1350 | int ret; |
1351 | if (datalen == 0) |
1352 | crReturnV; /* more data please */ |
1353 | ret = do_ssh_init(*data); |
1354 | data++; datalen--; |
1355 | if (ret == 0) |
1356 | break; |
1357 | } |
1358 | |
1359 | /* |
1360 | * We emerge from that loop when the initial negotiation is |
1361 | * over and we have selected an s_rdpkt function. Now pass |
1362 | * everything to s_rdpkt, and then pass the resulting packets |
1363 | * to the proper protocol handler. |
1364 | */ |
1365 | if (datalen == 0) |
1366 | crReturnV; |
1367 | while (1) { |
1368 | while (datalen > 0) { |
1369 | if ( s_rdpkt(&data, &datalen) == 0 ) { |
1370 | ssh_protocol(NULL, 0, 1); |
1371 | if (ssh_state == SSH_STATE_CLOSED) { |
1372 | return; |
1373 | } |
1374 | } |
1375 | } |
1376 | crReturnV; |
1377 | } |
1378 | crFinishV; |
1379 | } |
1380 | |
7e78000d |
1381 | static int ssh_closing (Plug plug, char *error_msg, int error_code, int calling_back) { |
1382 | ssh_state = SSH_STATE_CLOSED; |
1383 | sk_close(s); |
1384 | s = NULL; |
1385 | if (error_msg) { |
2c94fd1c |
1386 | /* A socket error has occurred. */ |
7e78000d |
1387 | connection_fatal (error_msg); |
1388 | } else { |
1389 | /* Otherwise, the remote side closed the connection normally. */ |
8df7a775 |
1390 | } |
7e78000d |
1391 | return 0; |
1392 | } |
1393 | |
1394 | static int ssh_receive(Plug plug, int urgent, char *data, int len) { |
8df7a775 |
1395 | ssh_gotdata (data, len); |
3257deae |
1396 | if (ssh_state == SSH_STATE_CLOSED) { |
1397 | if (s) { |
1398 | sk_close(s); |
1399 | s = NULL; |
1400 | } |
1401 | return 0; |
1402 | } |
fef97f43 |
1403 | return 1; |
374330e2 |
1404 | } |
1405 | |
fb09bf1c |
1406 | /* |
8df7a775 |
1407 | * Connect to specified host and port. |
1408 | * Returns an error message, or NULL on success. |
1409 | * Also places the canonical host name into `realhost'. |
1410 | */ |
1411 | static char *connect_to_host(char *host, int port, char **realhost) |
1412 | { |
7e78000d |
1413 | static struct plug_function_table fn_table = { |
1414 | ssh_closing, |
1415 | ssh_receive |
1416 | }, *fn_table_ptr = &fn_table; |
1417 | |
8df7a775 |
1418 | SockAddr addr; |
1419 | char *err; |
1420 | #ifdef FWHACK |
1421 | char *FWhost; |
1422 | int FWport; |
1423 | #endif |
1424 | |
dcbde236 |
1425 | savedhost = smalloc(1+strlen(host)); |
8df7a775 |
1426 | if (!savedhost) |
1427 | fatalbox("Out of memory"); |
1428 | strcpy(savedhost, host); |
1429 | |
1430 | if (port < 0) |
1431 | port = 22; /* default ssh port */ |
1432 | savedport = port; |
1433 | |
1434 | #ifdef FWHACK |
1435 | FWhost = host; |
1436 | FWport = port; |
1437 | host = FWSTR; |
1438 | port = 23; |
1439 | #endif |
1440 | |
1441 | /* |
1442 | * Try to find host. |
1443 | */ |
1444 | addr = sk_namelookup(host, realhost); |
1445 | if ( (err = sk_addr_error(addr)) ) |
1446 | return err; |
1447 | |
1448 | #ifdef FWHACK |
1449 | *realhost = FWhost; |
1450 | #endif |
1451 | |
1452 | /* |
1453 | * Open socket. |
1454 | */ |
7e78000d |
1455 | s = sk_new(addr, port, 0, 1, &fn_table_ptr); |
8df7a775 |
1456 | if ( (err = sk_socket_error(s)) ) |
1457 | return err; |
1458 | |
1459 | #ifdef FWHACK |
1460 | sk_write(s, "connect ", 8); |
1461 | sk_write(s, FWhost, strlen(FWhost)); |
1462 | { |
1463 | char buf[20]; |
1464 | sprintf(buf, " %d\n", FWport); |
1465 | sk_write(s, buf, strlen(buf)); |
1466 | } |
1467 | #endif |
1468 | |
1469 | return NULL; |
1470 | } |
1471 | |
1472 | /* |
fb09bf1c |
1473 | * Handle the key exchange and user authentication phases. |
1474 | */ |
e5574168 |
1475 | static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) |
fb09bf1c |
1476 | { |
374330e2 |
1477 | int i, j, len; |
374330e2 |
1478 | unsigned char *rsabuf, *keystr1, *keystr2; |
1479 | unsigned char cookie[8]; |
1480 | struct RSAKey servkey, hostkey; |
1481 | struct MD5Context md5c; |
ccbfb941 |
1482 | static unsigned long supported_ciphers_mask, supported_auths_mask; |
7cca0d81 |
1483 | static int tried_publickey; |
1484 | static unsigned char session_id[16]; |
bea1ef5f |
1485 | int cipher_type; |
b585ec46 |
1486 | static char username[100]; |
374330e2 |
1487 | |
374330e2 |
1488 | crBegin; |
1489 | |
fb09bf1c |
1490 | if (!ispkt) crWaitUntil(ispkt); |
374330e2 |
1491 | |
8d5de777 |
1492 | if (pktin.type != SSH1_SMSG_PUBLIC_KEY) { |
1493 | bombout(("Public key packet not received")); |
1494 | crReturn(0); |
1495 | } |
374330e2 |
1496 | |
c5e9c988 |
1497 | logevent("Received public keys"); |
374330e2 |
1498 | |
c5e9c988 |
1499 | memcpy(cookie, pktin.body, 8); |
374330e2 |
1500 | |
7cca0d81 |
1501 | i = makekey(pktin.body+8, &servkey, &keystr1, 0); |
1502 | j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0); |
374330e2 |
1503 | |
c5e9c988 |
1504 | /* |
1c2a93c4 |
1505 | * Log the host key fingerprint. |
c5e9c988 |
1506 | */ |
c5e9c988 |
1507 | { |
1508 | char logmsg[80]; |
1c2a93c4 |
1509 | logevent("Host key fingerprint is:"); |
c5e9c988 |
1510 | strcpy(logmsg, " "); |
1c2a93c4 |
1511 | hostkey.comment = NULL; |
1512 | rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg), |
1513 | &hostkey); |
c5e9c988 |
1514 | logevent(logmsg); |
1515 | } |
1516 | |
b96dc54c |
1517 | ssh1_remote_protoflags = GET_32BIT(pktin.body+8+i+j); |
fb09bf1c |
1518 | supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j); |
1519 | supported_auths_mask = GET_32BIT(pktin.body+16+i+j); |
bea1ef5f |
1520 | |
b96dc54c |
1521 | ssh1_local_protoflags = ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED; |
1522 | ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER; |
1523 | |
c5e9c988 |
1524 | MD5Init(&md5c); |
374330e2 |
1525 | MD5Update(&md5c, keystr2, hostkey.bytes); |
1526 | MD5Update(&md5c, keystr1, servkey.bytes); |
1527 | MD5Update(&md5c, pktin.body, 8); |
374330e2 |
1528 | MD5Final(session_id, &md5c); |
1529 | |
1530 | for (i=0; i<32; i++) |
1531 | session_key[i] = random_byte(); |
1532 | |
1533 | len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes); |
1534 | |
dcbde236 |
1535 | rsabuf = smalloc(len); |
374330e2 |
1536 | if (!rsabuf) |
1537 | fatalbox("Out of memory"); |
1538 | |
89ee5268 |
1539 | /* |
1540 | * Verify the host key. |
1541 | */ |
1542 | { |
1543 | /* |
1544 | * First format the key into a string. |
1545 | */ |
1546 | int len = rsastr_len(&hostkey); |
d5859615 |
1547 | char fingerprint[100]; |
dcbde236 |
1548 | char *keystr = smalloc(len); |
89ee5268 |
1549 | if (!keystr) |
1550 | fatalbox("Out of memory"); |
1551 | rsastr_fmt(keystr, &hostkey); |
d5859615 |
1552 | rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey); |
d4857987 |
1553 | verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint); |
dcbde236 |
1554 | sfree(keystr); |
89ee5268 |
1555 | } |
374330e2 |
1556 | |
1557 | for (i=0; i<32; i++) { |
1558 | rsabuf[i] = session_key[i]; |
1559 | if (i < 16) |
1560 | rsabuf[i] ^= session_id[i]; |
1561 | } |
1562 | |
1563 | if (hostkey.bytes > servkey.bytes) { |
1564 | rsaencrypt(rsabuf, 32, &servkey); |
1565 | rsaencrypt(rsabuf, servkey.bytes, &hostkey); |
1566 | } else { |
1567 | rsaencrypt(rsabuf, 32, &hostkey); |
1568 | rsaencrypt(rsabuf, hostkey.bytes, &servkey); |
1569 | } |
1570 | |
c5e9c988 |
1571 | logevent("Encrypted session key"); |
1572 | |
0a3f1d48 |
1573 | switch (cfg.cipher) { |
1574 | case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH; break; |
1575 | case CIPHER_DES: cipher_type = SSH_CIPHER_DES; break; |
1576 | case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES; break; |
1577 | case CIPHER_AES: |
1408a877 |
1578 | c_write_str("AES not supported in SSH1, falling back to 3DES\r\n"); |
0a3f1d48 |
1579 | cipher_type = SSH_CIPHER_3DES; |
1580 | break; |
1581 | } |
bea1ef5f |
1582 | if ((supported_ciphers_mask & (1 << cipher_type)) == 0) { |
1408a877 |
1583 | c_write_str("Selected cipher not supported, falling back to 3DES\r\n"); |
bea1ef5f |
1584 | cipher_type = SSH_CIPHER_3DES; |
a99a05c0 |
1585 | if ((supported_ciphers_mask & (1 << cipher_type)) == 0) { |
1586 | bombout(("Server violates SSH 1 protocol by " |
1587 | "not supporting 3DES encryption")); |
1588 | crReturn(0); |
1589 | } |
bea1ef5f |
1590 | } |
c5e9c988 |
1591 | switch (cipher_type) { |
1592 | case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break; |
1593 | case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break; |
1594 | case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break; |
1595 | } |
bea1ef5f |
1596 | |
e5574168 |
1597 | send_packet(SSH1_CMSG_SESSION_KEY, |
fb09bf1c |
1598 | PKT_CHAR, cipher_type, |
1599 | PKT_DATA, cookie, 8, |
1600 | PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF, |
1601 | PKT_DATA, rsabuf, len, |
b96dc54c |
1602 | PKT_INT, ssh1_local_protoflags, |
fb09bf1c |
1603 | PKT_END); |
1604 | |
c5e9c988 |
1605 | logevent("Trying to enable encryption..."); |
374330e2 |
1606 | |
dcbde236 |
1607 | sfree(rsabuf); |
374330e2 |
1608 | |
5e8358ad |
1609 | cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 : |
9697bfd2 |
1610 | cipher_type == SSH_CIPHER_DES ? &ssh_des : |
bea1ef5f |
1611 | &ssh_3des; |
374330e2 |
1612 | cipher->sesskey(session_key); |
1613 | |
fb09bf1c |
1614 | crWaitUntil(ispkt); |
374330e2 |
1615 | |
8d5de777 |
1616 | if (pktin.type != SSH1_SMSG_SUCCESS) { |
1617 | bombout(("Encryption not successfully enabled")); |
1618 | crReturn(0); |
1619 | } |
374330e2 |
1620 | |
c5e9c988 |
1621 | logevent("Successfully started encryption"); |
1622 | |
374330e2 |
1623 | fflush(stdout); |
1624 | { |
374330e2 |
1625 | static int pos = 0; |
1626 | static char c; |
67779be7 |
1627 | if ((flags & FLAG_INTERACTIVE) && !*cfg.username) { |
fa17a66e |
1628 | if (ssh_get_line) { |
1629 | if (!ssh_get_line("login as: ", |
1630 | username, sizeof(username), FALSE)) { |
1631 | /* |
1632 | * get_line failed to get a username. |
1633 | * Terminate. |
1634 | */ |
1635 | logevent("No username provided. Abandoning session."); |
1636 | ssh_state = SSH_STATE_CLOSED; |
1637 | crReturn(1); |
1638 | } |
1639 | } else { |
1640 | c_write_str("login as: "); |
1641 | ssh_send_ok = 1; |
1642 | while (pos >= 0) { |
1643 | crWaitUntil(!ispkt); |
1644 | while (inlen--) switch (c = *in++) { |
1645 | case 10: case 13: |
1646 | username[pos] = 0; |
1647 | pos = -1; |
1648 | break; |
1649 | case 8: case 127: |
1650 | if (pos > 0) { |
1651 | c_write_str("\b \b"); |
1652 | pos--; |
1653 | } |
1654 | break; |
1655 | case 21: case 27: |
1656 | while (pos > 0) { |
1657 | c_write_str("\b \b"); |
1658 | pos--; |
1659 | } |
1660 | break; |
1661 | case 3: case 4: |
1662 | random_save_seed(); |
1663 | exit(0); |
1664 | break; |
1665 | default: |
1666 | if (((c >= ' ' && c <= '~') || |
1667 | ((unsigned char)c >= 160)) && pos < 40) { |
1668 | username[pos++] = c; |
1669 | c_write(&c, 1); |
1670 | } |
1671 | break; |
1672 | } |
1673 | } |
1674 | c_write_str("\r\n"); |
1675 | username[strcspn(username, "\n\r")] = '\0'; |
1676 | } |
1677 | } else { |
374330e2 |
1678 | strncpy(username, cfg.username, 99); |
1679 | username[99] = '\0'; |
374330e2 |
1680 | } |
fb09bf1c |
1681 | |
e5574168 |
1682 | send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END); |
c5e9c988 |
1683 | { |
3c8e959b |
1684 | char userlog[22+sizeof(username)]; |
c5e9c988 |
1685 | sprintf(userlog, "Sent username \"%s\"", username); |
1686 | logevent(userlog); |
3c8e959b |
1687 | if (flags & FLAG_INTERACTIVE && |
1688 | (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) { |
1689 | strcat(userlog, "\r\n"); |
1408a877 |
1690 | c_write_str(userlog); |
3c8e959b |
1691 | } |
c5e9c988 |
1692 | } |
374330e2 |
1693 | } |
1694 | |
fb09bf1c |
1695 | crWaitUntil(ispkt); |
374330e2 |
1696 | |
7cca0d81 |
1697 | tried_publickey = 0; |
1698 | |
e5574168 |
1699 | while (pktin.type == SSH1_SMSG_FAILURE) { |
374330e2 |
1700 | static char password[100]; |
a52f067e |
1701 | static char prompt[200]; |
374330e2 |
1702 | static int pos; |
1703 | static char c; |
ccbfb941 |
1704 | static int pwpkt_type; |
ccbfb941 |
1705 | /* |
1706 | * Show password prompt, having first obtained it via a TIS |
18515c51 |
1707 | * or CryptoCard exchange if we're doing TIS or CryptoCard |
1708 | * authentication. |
ccbfb941 |
1709 | */ |
e5574168 |
1710 | pwpkt_type = SSH1_CMSG_AUTH_PASSWORD; |
5c58ad2d |
1711 | if (agent_exists()) { |
1712 | /* |
1713 | * Attempt RSA authentication using Pageant. |
1714 | */ |
1715 | static unsigned char request[5], *response, *p; |
1716 | static int responselen; |
1717 | static int i, nkeys; |
1718 | static int authed = FALSE; |
1719 | void *r; |
1720 | |
1721 | logevent("Pageant is running. Requesting keys."); |
1722 | |
1723 | /* Request the keys held by the agent. */ |
1724 | PUT_32BIT(request, 1); |
1983e559 |
1725 | request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES; |
5c58ad2d |
1726 | agent_query(request, 5, &r, &responselen); |
1727 | response = (unsigned char *)r; |
95797139 |
1728 | if (response && responselen >= 5 && |
1729 | response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) { |
5c58ad2d |
1730 | p = response + 5; |
1731 | nkeys = GET_32BIT(p); p += 4; |
6328ea7a |
1732 | { char buf[64]; sprintf(buf, "Pageant has %d SSH1 keys", nkeys); |
5c58ad2d |
1733 | logevent(buf); } |
1734 | for (i = 0; i < nkeys; i++) { |
1735 | static struct RSAKey key; |
1736 | static Bignum challenge; |
b8bb811a |
1737 | static char *commentp; |
1738 | static int commentlen; |
5c58ad2d |
1739 | |
1740 | { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i); |
1741 | logevent(buf); } |
1742 | p += 4; |
1743 | p += ssh1_read_bignum(p, &key.exponent); |
1744 | p += ssh1_read_bignum(p, &key.modulus); |
b8bb811a |
1745 | commentlen = GET_32BIT(p); p += 4; |
1746 | commentp = p; p += commentlen; |
5c58ad2d |
1747 | send_packet(SSH1_CMSG_AUTH_RSA, |
1748 | PKT_BIGNUM, key.modulus, PKT_END); |
1749 | crWaitUntil(ispkt); |
1750 | if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { |
1751 | logevent("Key refused"); |
1752 | continue; |
1753 | } |
1754 | logevent("Received RSA challenge"); |
1755 | ssh1_read_bignum(pktin.body, &challenge); |
1756 | { |
1757 | char *agentreq, *q, *ret; |
1758 | int len, retlen; |
1759 | len = 1 + 4; /* message type, bit count */ |
1760 | len += ssh1_bignum_length(key.exponent); |
1761 | len += ssh1_bignum_length(key.modulus); |
1762 | len += ssh1_bignum_length(challenge); |
1763 | len += 16; /* session id */ |
1764 | len += 4; /* response format */ |
dcbde236 |
1765 | agentreq = smalloc(4 + len); |
5c58ad2d |
1766 | PUT_32BIT(agentreq, len); |
1767 | q = agentreq + 4; |
1983e559 |
1768 | *q++ = SSH1_AGENTC_RSA_CHALLENGE; |
ddecd643 |
1769 | PUT_32BIT(q, bignum_bitcount(key.modulus)); |
5c58ad2d |
1770 | q += 4; |
1771 | q += ssh1_write_bignum(q, key.exponent); |
1772 | q += ssh1_write_bignum(q, key.modulus); |
1773 | q += ssh1_write_bignum(q, challenge); |
1774 | memcpy(q, session_id, 16); q += 16; |
1775 | PUT_32BIT(q, 1); /* response format */ |
1776 | agent_query(agentreq, len+4, &ret, &retlen); |
dcbde236 |
1777 | sfree(agentreq); |
5c58ad2d |
1778 | if (ret) { |
1983e559 |
1779 | if (ret[4] == SSH1_AGENT_RSA_RESPONSE) { |
5c58ad2d |
1780 | logevent("Sending Pageant's response"); |
1781 | send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE, |
1782 | PKT_DATA, ret+5, 16, PKT_END); |
dcbde236 |
1783 | sfree(ret); |
5c58ad2d |
1784 | crWaitUntil(ispkt); |
1785 | if (pktin.type == SSH1_SMSG_SUCCESS) { |
1786 | logevent("Pageant's response accepted"); |
c4fa2fce |
1787 | if (flags & FLAG_VERBOSE) { |
1408a877 |
1788 | c_write_str("Authenticated using RSA key \""); |
c4fa2fce |
1789 | c_write(commentp, commentlen); |
1408a877 |
1790 | c_write_str("\" from agent\r\n"); |
c4fa2fce |
1791 | } |
5c58ad2d |
1792 | authed = TRUE; |
1793 | } else |
1794 | logevent("Pageant's response not accepted"); |
1795 | } else { |
1796 | logevent("Pageant failed to answer challenge"); |
dcbde236 |
1797 | sfree(ret); |
5c58ad2d |
1798 | } |
1799 | } else { |
1800 | logevent("No reply received from Pageant"); |
1801 | } |
1802 | } |
1803 | freebn(key.exponent); |
1804 | freebn(key.modulus); |
1805 | freebn(challenge); |
1806 | if (authed) |
1807 | break; |
1808 | } |
1809 | } |
1810 | if (authed) |
1811 | break; |
1812 | } |
7cca0d81 |
1813 | if (*cfg.keyfile && !tried_publickey) |
1814 | pwpkt_type = SSH1_CMSG_AUTH_RSA; |
fb09bf1c |
1815 | |
a52f067e |
1816 | if (pktin.type == SSH1_SMSG_FAILURE && |
1817 | cfg.try_tis_auth && |
1818 | (supported_auths_mask & (1<<SSH1_AUTH_TIS))) { |
1819 | pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE; |
1820 | logevent("Requested TIS authentication"); |
1821 | send_packet(SSH1_CMSG_AUTH_TIS, PKT_END); |
1822 | crWaitUntil(ispkt); |
1823 | if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) { |
1824 | logevent("TIS authentication declined"); |
1825 | if (flags & FLAG_INTERACTIVE) |
1408a877 |
1826 | c_write_str("TIS authentication refused.\r\n"); |
a52f067e |
1827 | } else { |
1828 | int challengelen = ((pktin.body[0] << 24) | |
1829 | (pktin.body[1] << 16) | |
1830 | (pktin.body[2] << 8) | |
1831 | (pktin.body[3])); |
1832 | logevent("Received TIS challenge"); |
1833 | if (challengelen > sizeof(prompt)-1) |
1834 | challengelen = sizeof(prompt)-1; /* prevent overrun */ |
1835 | memcpy(prompt, pktin.body+4, challengelen); |
1836 | prompt[challengelen] = '\0'; |
1837 | } |
1838 | } |
1839 | if (pktin.type == SSH1_SMSG_FAILURE && |
1840 | cfg.try_tis_auth && |
1841 | (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) { |
1842 | pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE; |
1843 | logevent("Requested CryptoCard authentication"); |
1844 | send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END); |
1845 | crWaitUntil(ispkt); |
1846 | if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) { |
1847 | logevent("CryptoCard authentication declined"); |
1408a877 |
1848 | c_write_str("CryptoCard authentication refused.\r\n"); |
a52f067e |
1849 | } else { |
1850 | int challengelen = ((pktin.body[0] << 24) | |
1851 | (pktin.body[1] << 16) | |
1852 | (pktin.body[2] << 8) | |
1853 | (pktin.body[3])); |
1854 | logevent("Received CryptoCard challenge"); |
1855 | if (challengelen > sizeof(prompt)-1) |
1856 | challengelen = sizeof(prompt)-1; /* prevent overrun */ |
1857 | memcpy(prompt, pktin.body+4, challengelen); |
1858 | strncpy(prompt + challengelen, "\r\nResponse : ", |
1859 | sizeof(prompt)-challengelen); |
1860 | prompt[sizeof(prompt)-1] = '\0'; |
1861 | } |
1862 | } |
1863 | if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) { |
1864 | sprintf(prompt, "%.90s@%.90s's password: ", |
b585ec46 |
1865 | username, savedhost); |
a52f067e |
1866 | } |
1867 | if (pwpkt_type == SSH1_CMSG_AUTH_RSA) { |
1868 | char *comment = NULL; |
1869 | if (flags & FLAG_VERBOSE) |
1408a877 |
1870 | c_write_str("Trying public key authentication.\r\n"); |
a52f067e |
1871 | if (!rsakey_encrypted(cfg.keyfile, &comment)) { |
1872 | if (flags & FLAG_VERBOSE) |
1408a877 |
1873 | c_write_str("No passphrase required.\r\n"); |
a52f067e |
1874 | goto tryauth; |
1875 | } |
1876 | sprintf(prompt, "Passphrase for key \"%.100s\": ", comment); |
dcbde236 |
1877 | sfree(comment); |
a52f067e |
1878 | } |
1879 | |
fa17a66e |
1880 | if (ssh_get_line) { |
1881 | if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) { |
85ee8208 |
1882 | /* |
fa17a66e |
1883 | * get_line failed to get a password (for example |
1884 | * because one was supplied on the command line |
1885 | * which has already failed to work). Terminate. |
85ee8208 |
1886 | */ |
1887 | logevent("No more passwords to try"); |
1888 | ssh_state = SSH_STATE_CLOSED; |
1889 | crReturn(1); |
1890 | } |
fb09bf1c |
1891 | } else { |
1408a877 |
1892 | c_write_str(prompt); |
7cca0d81 |
1893 | pos = 0; |
67779be7 |
1894 | ssh_send_ok = 1; |
7cca0d81 |
1895 | while (pos >= 0) { |
1896 | crWaitUntil(!ispkt); |
1897 | while (inlen--) switch (c = *in++) { |
1898 | case 10: case 13: |
1899 | password[pos] = 0; |
1900 | pos = -1; |
1901 | break; |
1902 | case 8: case 127: |
1903 | if (pos > 0) |
1904 | pos--; |
1905 | break; |
1906 | case 21: case 27: |
1907 | pos = 0; |
1908 | break; |
1909 | case 3: case 4: |
1910 | random_save_seed(); |
1911 | exit(0); |
1912 | break; |
1913 | default: |
1914 | if (((c >= ' ' && c <= '~') || |
1915 | ((unsigned char)c >= 160)) && pos < sizeof(password)) |
1916 | password[pos++] = c; |
1917 | break; |
1918 | } |
1919 | } |
1408a877 |
1920 | c_write_str("\r\n"); |
a52f067e |
1921 | } |
fb09bf1c |
1922 | |
7cca0d81 |
1923 | tryauth: |
1924 | if (pwpkt_type == SSH1_CMSG_AUTH_RSA) { |
1925 | /* |
1926 | * Try public key authentication with the specified |
1927 | * key file. |
1928 | */ |
1929 | static struct RSAKey pubkey; |
1930 | static Bignum challenge, response; |
1931 | static int i; |
1932 | static unsigned char buffer[32]; |
1933 | |
1934 | tried_publickey = 1; |
65a22376 |
1935 | i = loadrsakey(cfg.keyfile, &pubkey, password); |
7cca0d81 |
1936 | if (i == 0) { |
1408a877 |
1937 | c_write_str("Couldn't load public key from "); |
1938 | c_write_str(cfg.keyfile); |
1939 | c_write_str(".\r\n"); |
7cca0d81 |
1940 | continue; /* go and try password */ |
1941 | } |
1942 | if (i == -1) { |
1408a877 |
1943 | c_write_str("Wrong passphrase.\r\n"); |
7cca0d81 |
1944 | tried_publickey = 0; |
1945 | continue; /* try again */ |
1946 | } |
1947 | |
1948 | /* |
1949 | * Send a public key attempt. |
1950 | */ |
1951 | send_packet(SSH1_CMSG_AUTH_RSA, |
1952 | PKT_BIGNUM, pubkey.modulus, PKT_END); |
1953 | |
1954 | crWaitUntil(ispkt); |
1955 | if (pktin.type == SSH1_SMSG_FAILURE) { |
1408a877 |
1956 | c_write_str("Server refused our public key.\r\n"); |
7cca0d81 |
1957 | continue; /* go and try password */ |
1958 | } |
8d5de777 |
1959 | if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { |
1960 | bombout(("Bizarre response to offer of public key")); |
1961 | crReturn(0); |
1962 | } |
7cca0d81 |
1963 | ssh1_read_bignum(pktin.body, &challenge); |
1964 | response = rsadecrypt(challenge, &pubkey); |
1965 | freebn(pubkey.private_exponent); /* burn the evidence */ |
1966 | |
3709bfe9 |
1967 | for (i = 0; i < 32; i++) { |
1968 | buffer[i] = bignum_byte(response, 31-i); |
7cca0d81 |
1969 | } |
1970 | |
1971 | MD5Init(&md5c); |
1972 | MD5Update(&md5c, buffer, 32); |
1973 | MD5Update(&md5c, session_id, 16); |
1974 | MD5Final(buffer, &md5c); |
1975 | |
1976 | send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE, |
1977 | PKT_DATA, buffer, 16, PKT_END); |
1978 | |
1979 | crWaitUntil(ispkt); |
1980 | if (pktin.type == SSH1_SMSG_FAILURE) { |
4017be6d |
1981 | if (flags & FLAG_VERBOSE) |
1408a877 |
1982 | c_write_str("Failed to authenticate with our public key.\r\n"); |
7cca0d81 |
1983 | continue; /* go and try password */ |
1984 | } else if (pktin.type != SSH1_SMSG_SUCCESS) { |
8d5de777 |
1985 | bombout(("Bizarre response to RSA authentication response")); |
1986 | crReturn(0); |
7cca0d81 |
1987 | } |
1988 | |
1989 | break; /* we're through! */ |
1990 | } else { |
39065bed |
1991 | if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) { |
1992 | /* |
1993 | * Defence against traffic analysis: we send a |
1994 | * whole bunch of packets containing strings of |
1995 | * different lengths. One of these strings is the |
1996 | * password, in a SSH1_CMSG_AUTH_PASSWORD packet. |
1997 | * The others are all random data in |
1998 | * SSH1_MSG_IGNORE packets. This way a passive |
1999 | * listener can't tell which is the password, and |
2000 | * hence can't deduce the password length. |
2001 | * |
2002 | * Anybody with a password length greater than 16 |
2003 | * bytes is going to have enough entropy in their |
2004 | * password that a listener won't find it _that_ |
2005 | * much help to know how long it is. So what we'll |
2006 | * do is: |
2007 | * |
2008 | * - if password length < 16, we send 15 packets |
2009 | * containing string lengths 1 through 15 |
2010 | * |
2011 | * - otherwise, we let N be the nearest multiple |
2012 | * of 8 below the password length, and send 8 |
2013 | * packets containing string lengths N through |
2014 | * N+7. This won't obscure the order of |
2015 | * magnitude of the password length, but it will |
2016 | * introduce a bit of extra uncertainty. |
7d503c31 |
2017 | * |
2018 | * A few servers (the old 1.2.18 through 1.2.22) |
2019 | * can't deal with SSH1_MSG_IGNORE. For these |
2020 | * servers, we need an alternative defence. We make |
2021 | * use of the fact that the password is interpreted |
2022 | * as a C string: so we can append a NUL, then some |
2023 | * random data. |
39065bed |
2024 | */ |
7d503c31 |
2025 | if (ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) { |
2026 | char string[64]; |
2027 | char *s; |
2028 | int len; |
2029 | |
2030 | len = strlen(password); |
2031 | if (len < sizeof(string)) { |
2032 | s = string; |
2033 | strcpy(string, password); |
2034 | len++; /* cover the zero byte */ |
2035 | while (len < sizeof(string)) { |
2036 | string[len++] = (char)random_byte(); |
2037 | } |
2038 | } else { |
2039 | s = password; |
2040 | } |
2041 | send_packet(pwpkt_type, PKT_INT, len, |
2042 | PKT_DATA, s, len, PKT_END); |
39065bed |
2043 | } else { |
7d503c31 |
2044 | int bottom, top, pwlen, i; |
2045 | char *randomstr; |
2046 | |
2047 | pwlen = strlen(password); |
2048 | if (pwlen < 16) { |
98c84eb4 |
2049 | bottom = 0; /* zero length passwords are OK! :-) */ |
7d503c31 |
2050 | top = 15; |
2051 | } else { |
2052 | bottom = pwlen &~ 7; |
2053 | top = bottom + 7; |
2054 | } |
39065bed |
2055 | |
7d503c31 |
2056 | assert(pwlen >= bottom && pwlen <= top); |
39065bed |
2057 | |
7d503c31 |
2058 | randomstr = smalloc(top+1); |
39065bed |
2059 | |
7d503c31 |
2060 | for (i = bottom; i <= top; i++) { |
2061 | if (i == pwlen) |
2062 | defer_packet(pwpkt_type, PKT_STR, password, PKT_END); |
2063 | else { |
2064 | for (j = 0; j < i; j++) { |
2065 | do { |
2066 | randomstr[j] = random_byte(); |
2067 | } while (randomstr[j] == '\0'); |
2068 | } |
2069 | randomstr[i] = '\0'; |
2070 | defer_packet(SSH1_MSG_IGNORE, |
2071 | PKT_STR, randomstr, PKT_END); |
39065bed |
2072 | } |
39065bed |
2073 | } |
7d503c31 |
2074 | ssh_pkt_defersend(); |
39065bed |
2075 | } |
39065bed |
2076 | } else { |
2077 | send_packet(pwpkt_type, PKT_STR, password, PKT_END); |
2078 | } |
7cca0d81 |
2079 | } |
c5e9c988 |
2080 | logevent("Sent password"); |
374330e2 |
2081 | memset(password, 0, strlen(password)); |
fb09bf1c |
2082 | crWaitUntil(ispkt); |
e5574168 |
2083 | if (pktin.type == SSH1_SMSG_FAILURE) { |
4017be6d |
2084 | if (flags & FLAG_VERBOSE) |
1408a877 |
2085 | c_write_str("Access denied\r\n"); |
c5e9c988 |
2086 | logevent("Authentication refused"); |
e5574168 |
2087 | } else if (pktin.type == SSH1_MSG_DISCONNECT) { |
fb09bf1c |
2088 | logevent("Received disconnect request"); |
85ee8208 |
2089 | ssh_state = SSH_STATE_CLOSED; |
2090 | crReturn(1); |
e5574168 |
2091 | } else if (pktin.type != SSH1_SMSG_SUCCESS) { |
8d5de777 |
2092 | bombout(("Strange packet received, type %d", pktin.type)); |
2093 | crReturn(0); |
374330e2 |
2094 | } |
2095 | } |
2096 | |
c5e9c988 |
2097 | logevent("Authentication successful"); |
2098 | |
fb09bf1c |
2099 | crFinish(1); |
2100 | } |
2101 | |
9c964e85 |
2102 | void sshfwd_close(struct ssh_channel *c) { |
80e48603 |
2103 | if (c && !c->closes) { |
783415f8 |
2104 | if (ssh_version == 1) { |
2105 | send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, PKT_END); |
2106 | } else { |
2107 | ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); |
2108 | ssh2_pkt_adduint32(c->remoteid); |
2109 | ssh2_pkt_send(); |
2110 | } |
2111 | c->closes = 1; |
2112 | if (c->type == CHAN_X11) { |
2113 | c->u.x11.s = NULL; |
2114 | logevent("X11 connection terminated"); |
2115 | } |
2116 | } |
9c964e85 |
2117 | } |
2118 | |
2119 | void sshfwd_write(struct ssh_channel *c, char *buf, int len) { |
783415f8 |
2120 | if (ssh_version == 1) { |
2121 | send_packet(SSH1_MSG_CHANNEL_DATA, |
2122 | PKT_INT, c->remoteid, |
2123 | PKT_INT, len, |
2124 | PKT_DATA, buf, len, |
2125 | PKT_END); |
2126 | } else { |
2127 | ssh2_add_channel_data(c, buf, len); |
2128 | ssh2_try_send(c); |
2129 | } |
9c964e85 |
2130 | } |
2131 | |
e5574168 |
2132 | static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) { |
fb09bf1c |
2133 | crBegin; |
2134 | |
2135 | random_init(); |
2136 | |
e5574168 |
2137 | while (!do_ssh1_login(in, inlen, ispkt)) { |
fb09bf1c |
2138 | crReturnV; |
85ee8208 |
2139 | } |
2140 | if (ssh_state == SSH_STATE_CLOSED) |
2141 | crReturnV; |
fb09bf1c |
2142 | |
979310f1 |
2143 | if (cfg.agentfwd && agent_exists()) { |
dacbd0e8 |
2144 | logevent("Requesting agent forwarding"); |
2145 | send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END); |
2146 | do { crReturnV; } while (!ispkt); |
2147 | if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) { |
8d5de777 |
2148 | bombout(("Protocol confusion")); |
2149 | crReturnV; |
dacbd0e8 |
2150 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
2151 | logevent("Agent forwarding refused"); |
db7d555c |
2152 | } else { |
dacbd0e8 |
2153 | logevent("Agent forwarding enabled"); |
db7d555c |
2154 | ssh_agentfwd_enabled = TRUE; |
2155 | } |
dacbd0e8 |
2156 | } |
2157 | |
9c964e85 |
2158 | if (cfg.x11_forward) { |
2159 | char proto[20], data[64]; |
2160 | logevent("Requesting X11 forwarding"); |
2161 | x11_invent_auth(proto, sizeof(proto), data, sizeof(data)); |
b96dc54c |
2162 | if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) { |
2163 | send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING, |
2164 | PKT_STR, proto, PKT_STR, data, |
2165 | PKT_INT, 0, |
2166 | PKT_END); |
2167 | } else { |
2168 | send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING, |
2169 | PKT_STR, proto, PKT_STR, data, |
2170 | PKT_END); |
2171 | } |
9c964e85 |
2172 | do { crReturnV; } while (!ispkt); |
2173 | if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) { |
2174 | bombout(("Protocol confusion")); |
2175 | crReturnV; |
2176 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
2177 | logevent("X11 forwarding refused"); |
2178 | } else { |
2179 | logevent("X11 forwarding enabled"); |
2180 | ssh_X11_fwd_enabled = TRUE; |
2181 | } |
2182 | } |
2183 | |
fef97f43 |
2184 | if (!cfg.nopty) { |
e5574168 |
2185 | send_packet(SSH1_CMSG_REQUEST_PTY, |
fb09bf1c |
2186 | PKT_STR, cfg.termtype, |
2187 | PKT_INT, rows, PKT_INT, cols, |
2188 | PKT_INT, 0, PKT_INT, 0, |
2189 | PKT_CHAR, 0, |
2190 | PKT_END); |
fef97f43 |
2191 | ssh_state = SSH_STATE_INTERMED; |
2192 | do { crReturnV; } while (!ispkt); |
e5574168 |
2193 | if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) { |
8d5de777 |
2194 | bombout(("Protocol confusion")); |
2195 | crReturnV; |
e5574168 |
2196 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
1408a877 |
2197 | c_write_str("Server refused to allocate pty\r\n"); |
0965bee0 |
2198 | ssh_editing = ssh_echoing = 1; |
fef97f43 |
2199 | } |
c5e9c988 |
2200 | logevent("Allocated pty"); |
0965bee0 |
2201 | } else { |
2202 | ssh_editing = ssh_echoing = 1; |
374330e2 |
2203 | } |
2204 | |
4ba9b64b |
2205 | if (cfg.compression) { |
2206 | send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END); |
2207 | do { crReturnV; } while (!ispkt); |
2208 | if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) { |
2209 | bombout(("Protocol confusion")); |
2210 | crReturnV; |
2211 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
1408a877 |
2212 | c_write_str("Server refused to compress\r\n"); |
4ba9b64b |
2213 | } |
2214 | logevent("Started compression"); |
2215 | ssh1_compressing = TRUE; |
2216 | zlib_compress_init(); |
2217 | zlib_decompress_init(); |
2218 | } |
2219 | |
96621a84 |
2220 | if (*cfg.remote_cmd_ptr) |
2221 | send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd_ptr, PKT_END); |
6abbf9e3 |
2222 | else |
2223 | send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END); |
c5e9c988 |
2224 | logevent("Started session"); |
374330e2 |
2225 | |
2226 | ssh_state = SSH_STATE_SESSION; |
2227 | if (size_needed) |
2228 | ssh_size(); |
3687d221 |
2229 | if (eof_needed) |
2230 | ssh_special(TS_EOF); |
374330e2 |
2231 | |
0965bee0 |
2232 | ldisc_send(NULL, 0); /* cause ldisc to notice changes */ |
8ccc75b0 |
2233 | ssh_send_ok = 1; |
dacbd0e8 |
2234 | ssh_channels = newtree234(ssh_channelcmp); |
374330e2 |
2235 | while (1) { |
2236 | crReturnV; |
2237 | if (ispkt) { |
e5574168 |
2238 | if (pktin.type == SSH1_SMSG_STDOUT_DATA || |
2239 | pktin.type == SSH1_SMSG_STDERR_DATA) { |
fb09bf1c |
2240 | long len = GET_32BIT(pktin.body); |
fe50e814 |
2241 | from_backend(pktin.type == SSH1_SMSG_STDERR_DATA, |
2242 | pktin.body+4, len); |
e5574168 |
2243 | } else if (pktin.type == SSH1_MSG_DISCONNECT) { |
21248260 |
2244 | ssh_state = SSH_STATE_CLOSED; |
c5e9c988 |
2245 | logevent("Received disconnect request"); |
3257deae |
2246 | crReturnV; |
9c964e85 |
2247 | } else if (pktin.type == SSH1_SMSG_X11_OPEN) { |
2248 | /* Remote side is trying to open a channel to talk to our |
2249 | * X-Server. Give them back a local channel number. */ |
260f3dec |
2250 | struct ssh_channel *c; |
9c964e85 |
2251 | |
2252 | logevent("Received X11 connect request"); |
2253 | /* Refuse if X11 forwarding is disabled. */ |
2254 | if (!ssh_X11_fwd_enabled) { |
2255 | send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE, |
2256 | PKT_INT, GET_32BIT(pktin.body), |
2257 | PKT_END); |
2258 | logevent("Rejected X11 connect request"); |
2259 | } else { |
9c964e85 |
2260 | c = smalloc(sizeof(struct ssh_channel)); |
2261 | |
0c6c9a70 |
2262 | if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) { |
9c964e85 |
2263 | logevent("opening X11 forward connection failed"); |
2264 | sfree(c); |
2265 | send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE, |
2266 | PKT_INT, GET_32BIT(pktin.body), |
2267 | PKT_END); |
2268 | } else { |
2269 | logevent("opening X11 forward connection succeeded"); |
9c964e85 |
2270 | c->remoteid = GET_32BIT(pktin.body); |
d2371c81 |
2271 | c->localid = alloc_channel_id(); |
9c964e85 |
2272 | c->closes = 0; |
783415f8 |
2273 | c->type = CHAN_X11; /* identify channel type */ |
9c964e85 |
2274 | add234(ssh_channels, c); |
2275 | send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, |
2276 | PKT_INT, c->remoteid, PKT_INT, c->localid, |
2277 | PKT_END); |
2278 | logevent("Opened X11 forward channel"); |
2279 | } |
2280 | } |
dacbd0e8 |
2281 | } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) { |
2282 | /* Remote side is trying to open a channel to talk to our |
2283 | * agent. Give them back a local channel number. */ |
dacbd0e8 |
2284 | struct ssh_channel *c; |
db7d555c |
2285 | |
2286 | /* Refuse if agent forwarding is disabled. */ |
2287 | if (!ssh_agentfwd_enabled) { |
2288 | send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE, |
2289 | PKT_INT, GET_32BIT(pktin.body), |
2290 | PKT_END); |
2291 | } else { |
dcbde236 |
2292 | c = smalloc(sizeof(struct ssh_channel)); |
db7d555c |
2293 | c->remoteid = GET_32BIT(pktin.body); |
d2371c81 |
2294 | c->localid = alloc_channel_id(); |
db7d555c |
2295 | c->closes = 0; |
783415f8 |
2296 | c->type = CHAN_AGENT; /* identify channel type */ |
db7d555c |
2297 | c->u.a.lensofar = 0; |
2298 | add234(ssh_channels, c); |
2299 | send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, |
2300 | PKT_INT, c->remoteid, PKT_INT, c->localid, |
2301 | PKT_END); |
2302 | } |
2303 | } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE || |
2304 | pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) { |
dacbd0e8 |
2305 | /* Remote side closes a channel. */ |
d211621f |
2306 | unsigned i = GET_32BIT(pktin.body); |
dacbd0e8 |
2307 | struct ssh_channel *c; |
2308 | c = find234(ssh_channels, &i, ssh_channelfind); |
2309 | if (c) { |
2310 | int closetype; |
2311 | closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2); |
824e9f94 |
2312 | if (!(c->closes & closetype)) |
2313 | send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END); |
783415f8 |
2314 | if ((c->closes == 0) && (c->type == CHAN_X11)) { |
9c964e85 |
2315 | logevent("X11 connection closed"); |
2316 | assert(c->u.x11.s != NULL); |
2317 | x11_close(c->u.x11.s); |
2318 | c->u.x11.s = NULL; |
2319 | } |
dacbd0e8 |
2320 | c->closes |= closetype; |
2321 | if (c->closes == 3) { |
2322 | del234(ssh_channels, c); |
dcbde236 |
2323 | sfree(c); |
dacbd0e8 |
2324 | } |
2325 | } |
2326 | } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) { |
2327 | /* Data sent down one of our channels. */ |
2328 | int i = GET_32BIT(pktin.body); |
2329 | int len = GET_32BIT(pktin.body+4); |
2330 | unsigned char *p = pktin.body+8; |
2331 | struct ssh_channel *c; |
2332 | c = find234(ssh_channels, &i, ssh_channelfind); |
2333 | if (c) { |
2334 | switch(c->type) { |
783415f8 |
2335 | case CHAN_X11: |
9c964e85 |
2336 | x11_send(c->u.x11.s, p, len); |
2337 | break; |
783415f8 |
2338 | case CHAN_AGENT: |
dacbd0e8 |
2339 | /* Data for an agent message. Buffer it. */ |
2340 | while (len > 0) { |
2341 | if (c->u.a.lensofar < 4) { |
2342 | int l = min(4 - c->u.a.lensofar, len); |
2343 | memcpy(c->u.a.msglen + c->u.a.lensofar, p, l); |
2344 | p += l; len -= l; c->u.a.lensofar += l; |
2345 | } |
2346 | if (c->u.a.lensofar == 4) { |
2347 | c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen); |
dcbde236 |
2348 | c->u.a.message = smalloc(c->u.a.totallen); |
dacbd0e8 |
2349 | memcpy(c->u.a.message, c->u.a.msglen, 4); |
2350 | } |
2351 | if (c->u.a.lensofar >= 4 && len > 0) { |
2352 | int l = min(c->u.a.totallen - c->u.a.lensofar, len); |
2353 | memcpy(c->u.a.message + c->u.a.lensofar, p, l); |
2354 | p += l; len -= l; c->u.a.lensofar += l; |
2355 | } |
2356 | if (c->u.a.lensofar == c->u.a.totallen) { |
2357 | void *reply, *sentreply; |
2358 | int replylen; |
2359 | agent_query(c->u.a.message, c->u.a.totallen, |
2360 | &reply, &replylen); |
2361 | if (reply) |
2362 | sentreply = reply; |
2363 | else { |
2364 | /* Fake SSH_AGENT_FAILURE. */ |
2365 | sentreply = "\0\0\0\1\5"; |
2366 | replylen = 5; |
2367 | } |
2368 | send_packet(SSH1_MSG_CHANNEL_DATA, |
2369 | PKT_INT, c->remoteid, |
2370 | PKT_INT, replylen, |
2371 | PKT_DATA, sentreply, replylen, |
2372 | PKT_END); |
2373 | if (reply) |
dcbde236 |
2374 | sfree(reply); |
2375 | sfree(c->u.a.message); |
dacbd0e8 |
2376 | c->u.a.lensofar = 0; |
2377 | } |
2378 | } |
2379 | break; |
2380 | } |
2381 | } |
e5574168 |
2382 | } else if (pktin.type == SSH1_SMSG_SUCCESS) { |
972a41c8 |
2383 | /* may be from EXEC_SHELL on some servers */ |
e5574168 |
2384 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
972a41c8 |
2385 | /* may be from EXEC_SHELL on some servers |
374330e2 |
2386 | * if no pty is available or in other odd cases. Ignore */ |
e5574168 |
2387 | } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) { |
2388 | send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END); |
374330e2 |
2389 | } else { |
8d5de777 |
2390 | bombout(("Strange packet received: type %d", pktin.type)); |
2391 | crReturnV; |
374330e2 |
2392 | } |
2393 | } else { |
8df7a775 |
2394 | while (inlen > 0) { |
2395 | int len = min(inlen, 512); |
2396 | send_packet(SSH1_CMSG_STDIN_DATA, |
2397 | PKT_INT, len, PKT_DATA, in, len, PKT_END); |
2398 | in += len; |
2399 | inlen -= len; |
2400 | } |
374330e2 |
2401 | } |
2402 | } |
2403 | |
2404 | crFinishV; |
2405 | } |
2406 | |
2407 | /* |
e5574168 |
2408 | * Utility routine for decoding comma-separated strings in KEXINIT. |
2409 | */ |
75cab814 |
2410 | static int in_commasep_string(char *needle, char *haystack, int haylen) { |
e5574168 |
2411 | int needlen = strlen(needle); |
2412 | while (1) { |
2413 | /* |
2414 | * Is it at the start of the string? |
2415 | */ |
2416 | if (haylen >= needlen && /* haystack is long enough */ |
2417 | !memcmp(needle, haystack, needlen) && /* initial match */ |
2418 | (haylen == needlen || haystack[needlen] == ',') |
2419 | /* either , or EOS follows */ |
2420 | ) |
2421 | return 1; |
2422 | /* |
2423 | * If not, search for the next comma and resume after that. |
2424 | * If no comma found, terminate. |
2425 | */ |
2426 | while (haylen > 0 && *haystack != ',') |
2427 | haylen--, haystack++; |
2428 | if (haylen == 0) |
2429 | return 0; |
2430 | haylen--, haystack++; /* skip over comma itself */ |
2431 | } |
2432 | } |
2433 | |
2434 | /* |
d39f364a |
2435 | * SSH2 key creation method. |
2436 | */ |
5e0d7cb8 |
2437 | static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr, char *keyspace) { |
d39f364a |
2438 | SHA_State s; |
2439 | /* First 20 bytes. */ |
2440 | SHA_Init(&s); |
2441 | sha_mpint(&s, K); |
2442 | SHA_Bytes(&s, H, 20); |
2443 | SHA_Bytes(&s, &chr, 1); |
5e0d7cb8 |
2444 | SHA_Bytes(&s, sessid, 20); |
d39f364a |
2445 | SHA_Final(&s, keyspace); |
2446 | /* Next 20 bytes. */ |
2447 | SHA_Init(&s); |
2448 | sha_mpint(&s, K); |
2449 | SHA_Bytes(&s, H, 20); |
2450 | SHA_Bytes(&s, keyspace, 20); |
2451 | SHA_Final(&s, keyspace+20); |
2452 | } |
2453 | |
2454 | /* |
7cca0d81 |
2455 | * Handle the SSH2 transport layer. |
e5574168 |
2456 | */ |
7cca0d81 |
2457 | static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt) |
e5574168 |
2458 | { |
7bd5a860 |
2459 | static int i, j, len, nbits, pbits; |
e5574168 |
2460 | static char *str; |
a92dd380 |
2461 | static Bignum p, g, e, f, K; |
2462 | static int kex_init_value, kex_reply_value; |
7591b9ff |
2463 | static const struct ssh_mac **maclist; |
8b2715b2 |
2464 | static int nmacs; |
0a3f1d48 |
2465 | static const struct ssh2_cipher *cscipher_tobe = NULL; |
2466 | static const struct ssh2_cipher *sccipher_tobe = NULL; |
57476f6b |
2467 | static const struct ssh_mac *csmac_tobe = NULL; |
2468 | static const struct ssh_mac *scmac_tobe = NULL; |
2469 | static const struct ssh_compress *cscomp_tobe = NULL; |
2470 | static const struct ssh_compress *sccomp_tobe = NULL; |
d5859615 |
2471 | static char *hostkeydata, *sigdata, *keystr, *fingerprint; |
e5574168 |
2472 | static int hostkeylen, siglen; |
e055a386 |
2473 | static void *hkey; /* actual host key */ |
e5574168 |
2474 | static unsigned char exchange_hash[20]; |
d39f364a |
2475 | static unsigned char keyspace[40]; |
0a3f1d48 |
2476 | static const struct ssh2_ciphers *preferred_cipher; |
4ba9b64b |
2477 | static const struct ssh_compress *preferred_comp; |
0db56f73 |
2478 | static int first_kex; |
e5574168 |
2479 | |
2480 | crBegin; |
7cca0d81 |
2481 | random_init(); |
0db56f73 |
2482 | first_kex = 1; |
e5574168 |
2483 | |
5e8358ad |
2484 | /* |
4ba9b64b |
2485 | * Set up the preferred cipher and compression. |
5e8358ad |
2486 | */ |
2487 | if (cfg.cipher == CIPHER_BLOWFISH) { |
0a3f1d48 |
2488 | preferred_cipher = &ssh2_blowfish; |
5e8358ad |
2489 | } else if (cfg.cipher == CIPHER_DES) { |
2490 | logevent("Single DES not supported in SSH2; using 3DES"); |
0a3f1d48 |
2491 | preferred_cipher = &ssh2_3des; |
5e8358ad |
2492 | } else if (cfg.cipher == CIPHER_3DES) { |
0a3f1d48 |
2493 | preferred_cipher = &ssh2_3des; |
2494 | } else if (cfg.cipher == CIPHER_AES) { |
2495 | preferred_cipher = &ssh2_aes; |
5e8358ad |
2496 | } else { |
2497 | /* Shouldn't happen, but we do want to initialise to _something_. */ |
0a3f1d48 |
2498 | preferred_cipher = &ssh2_3des; |
5e8358ad |
2499 | } |
4ba9b64b |
2500 | if (cfg.compression) |
2501 | preferred_comp = &ssh_zlib; |
2502 | else |
2503 | preferred_comp = &ssh_comp_none; |
5e8358ad |
2504 | |
7591b9ff |
2505 | /* |
2506 | * Be prepared to work around the buggy MAC problem. |
2507 | */ |
7d503c31 |
2508 | if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC)) |
8b2715b2 |
2509 | maclist = buggymacs, nmacs = lenof(buggymacs); |
7591b9ff |
2510 | else |
8b2715b2 |
2511 | maclist = macs, nmacs = lenof(macs); |
7591b9ff |
2512 | |
7cca0d81 |
2513 | begin_key_exchange: |
e5574168 |
2514 | /* |
2515 | * Construct and send our key exchange packet. |
2516 | */ |
2517 | ssh2_pkt_init(SSH2_MSG_KEXINIT); |
2518 | for (i = 0; i < 16; i++) |
2519 | ssh2_pkt_addbyte((unsigned char)random_byte()); |
2520 | /* List key exchange algorithms. */ |
2521 | ssh2_pkt_addstring_start(); |
2522 | for (i = 0; i < lenof(kex_algs); i++) { |
2523 | ssh2_pkt_addstring_str(kex_algs[i]->name); |
2524 | if (i < lenof(kex_algs)-1) |
2525 | ssh2_pkt_addstring_str(","); |
2526 | } |
2527 | /* List server host key algorithms. */ |
2528 | ssh2_pkt_addstring_start(); |
2529 | for (i = 0; i < lenof(hostkey_algs); i++) { |
2530 | ssh2_pkt_addstring_str(hostkey_algs[i]->name); |
2531 | if (i < lenof(hostkey_algs)-1) |
2532 | ssh2_pkt_addstring_str(","); |
2533 | } |
2534 | /* List client->server encryption algorithms. */ |
2535 | ssh2_pkt_addstring_start(); |
729e54b4 |
2536 | for (i = 0; i < lenof(ciphers)+1; i++) { |
0a3f1d48 |
2537 | const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1]; |
2538 | for (j = 0; j < c->nciphers; j++) { |
2539 | ssh2_pkt_addstring_str(c->list[j]->name); |
2540 | if (i < lenof(ciphers) || j < c->nciphers-1) |
2541 | ssh2_pkt_addstring_str(","); |
2542 | } |
e5574168 |
2543 | } |
2544 | /* List server->client encryption algorithms. */ |
2545 | ssh2_pkt_addstring_start(); |
729e54b4 |
2546 | for (i = 0; i < lenof(ciphers)+1; i++) { |
0a3f1d48 |
2547 | const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1]; |
2548 | for (j = 0; j < c->nciphers; j++) { |
2549 | ssh2_pkt_addstring_str(c->list[j]->name); |
2550 | if (i < lenof(ciphers) || j < c->nciphers-1) |
2551 | ssh2_pkt_addstring_str(","); |
2552 | } |
e5574168 |
2553 | } |
2554 | /* List client->server MAC algorithms. */ |
2555 | ssh2_pkt_addstring_start(); |
8b2715b2 |
2556 | for (i = 0; i < nmacs; i++) { |
7591b9ff |
2557 | ssh2_pkt_addstring_str(maclist[i]->name); |
8b2715b2 |
2558 | if (i < nmacs-1) |
e5574168 |
2559 | ssh2_pkt_addstring_str(","); |
2560 | } |
2561 | /* List server->client MAC algorithms. */ |
2562 | ssh2_pkt_addstring_start(); |
8b2715b2 |
2563 | for (i = 0; i < nmacs; i++) { |
7591b9ff |
2564 | ssh2_pkt_addstring_str(maclist[i]->name); |
8b2715b2 |
2565 | if (i < nmacs-1) |
e5574168 |
2566 | ssh2_pkt_addstring_str(","); |
2567 | } |
2568 | /* List client->server compression algorithms. */ |
2569 | ssh2_pkt_addstring_start(); |
4ba9b64b |
2570 | for (i = 0; i < lenof(compressions)+1; i++) { |
2571 | const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1]; |
2572 | ssh2_pkt_addstring_str(c->name); |
2573 | if (i < lenof(compressions)) |
e5574168 |
2574 | ssh2_pkt_addstring_str(","); |
2575 | } |
2576 | /* List server->client compression algorithms. */ |
2577 | ssh2_pkt_addstring_start(); |
4ba9b64b |
2578 | for (i = 0; i < lenof(compressions)+1; i++) { |
2579 | const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1]; |
2580 | ssh2_pkt_addstring_str(c->name); |
2581 | if (i < lenof(compressions)) |
e5574168 |
2582 | ssh2_pkt_addstring_str(","); |
2583 | } |
2584 | /* List client->server languages. Empty list. */ |
2585 | ssh2_pkt_addstring_start(); |
2586 | /* List server->client languages. Empty list. */ |
2587 | ssh2_pkt_addstring_start(); |
2588 | /* First KEX packet does _not_ follow, because we're not that brave. */ |
2589 | ssh2_pkt_addbool(FALSE); |
2590 | /* Reserved. */ |
2591 | ssh2_pkt_adduint32(0); |
0db56f73 |
2592 | |
2593 | exhash = exhashbase; |
e5574168 |
2594 | sha_string(&exhash, pktout.data+5, pktout.length-5); |
0db56f73 |
2595 | |
e5574168 |
2596 | ssh2_pkt_send(); |
2597 | |
2598 | if (!ispkt) crWaitUntil(ispkt); |
2599 | sha_string(&exhash, pktin.data+5, pktin.length-5); |
2600 | |
2601 | /* |
2602 | * Now examine the other side's KEXINIT to see what we're up |
2603 | * to. |
2604 | */ |
7cca0d81 |
2605 | if (pktin.type != SSH2_MSG_KEXINIT) { |
8d5de777 |
2606 | bombout(("expected key exchange packet from server")); |
2607 | crReturn(0); |
7cca0d81 |
2608 | } |
e5574168 |
2609 | kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL; |
2610 | csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL; |
2611 | pktin.savedpos += 16; /* skip garbage cookie */ |
2612 | ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */ |
2613 | for (i = 0; i < lenof(kex_algs); i++) { |
2614 | if (in_commasep_string(kex_algs[i]->name, str, len)) { |
2615 | kex = kex_algs[i]; |
2616 | break; |
2617 | } |
2618 | } |
2619 | ssh2_pkt_getstring(&str, &len); /* host key algorithms */ |
2620 | for (i = 0; i < lenof(hostkey_algs); i++) { |
2621 | if (in_commasep_string(hostkey_algs[i]->name, str, len)) { |
2622 | hostkey = hostkey_algs[i]; |
2623 | break; |
2624 | } |
2625 | } |
2626 | ssh2_pkt_getstring(&str, &len); /* client->server cipher */ |
729e54b4 |
2627 | for (i = 0; i < lenof(ciphers)+1; i++) { |
0a3f1d48 |
2628 | const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1]; |
2629 | for (j = 0; j < c->nciphers; j++) { |
2630 | if (in_commasep_string(c->list[j]->name, str, len)) { |
2631 | cscipher_tobe = c->list[j]; |
2632 | break; |
2633 | } |
e5574168 |
2634 | } |
0a3f1d48 |
2635 | if (cscipher_tobe) |
2636 | break; |
e5574168 |
2637 | } |
2638 | ssh2_pkt_getstring(&str, &len); /* server->client cipher */ |
729e54b4 |
2639 | for (i = 0; i < lenof(ciphers)+1; i++) { |
0a3f1d48 |
2640 | const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1]; |
2641 | for (j = 0; j < c->nciphers; j++) { |
2642 | if (in_commasep_string(c->list[j]->name, str, len)) { |
2643 | sccipher_tobe = c->list[j]; |
2644 | break; |
2645 | } |
e5574168 |
2646 | } |
0a3f1d48 |
2647 | if (sccipher_tobe) |
2648 | break; |
e5574168 |
2649 | } |
2650 | ssh2_pkt_getstring(&str, &len); /* client->server mac */ |
8b2715b2 |
2651 | for (i = 0; i < nmacs; i++) { |
7591b9ff |
2652 | if (in_commasep_string(maclist[i]->name, str, len)) { |
2653 | csmac_tobe = maclist[i]; |
e5574168 |
2654 | break; |
2655 | } |
2656 | } |
2657 | ssh2_pkt_getstring(&str, &len); /* server->client mac */ |
8b2715b2 |
2658 | for (i = 0; i < nmacs; i++) { |
7591b9ff |
2659 | if (in_commasep_string(maclist[i]->name, str, len)) { |
2660 | scmac_tobe = maclist[i]; |
e5574168 |
2661 | break; |
2662 | } |
2663 | } |
2664 | ssh2_pkt_getstring(&str, &len); /* client->server compression */ |
4ba9b64b |
2665 | for (i = 0; i < lenof(compressions)+1; i++) { |
2666 | const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1]; |
2667 | if (in_commasep_string(c->name, str, len)) { |
2668 | cscomp_tobe = c; |
e5574168 |
2669 | break; |
2670 | } |
2671 | } |
2672 | ssh2_pkt_getstring(&str, &len); /* server->client compression */ |
4ba9b64b |
2673 | for (i = 0; i < lenof(compressions)+1; i++) { |
2674 | const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1]; |
2675 | if (in_commasep_string(c->name, str, len)) { |
2676 | sccomp_tobe = c; |
e5574168 |
2677 | break; |
2678 | } |
2679 | } |
e5574168 |
2680 | |
2681 | /* |
7bd5a860 |
2682 | * Work out the number of bits of key we will need from the key |
2683 | * exchange. We start with the maximum key length of either |
2684 | * cipher... |
2685 | */ |
2686 | { |
2687 | int csbits, scbits; |
2688 | |
2689 | csbits = cscipher_tobe->keylen; |
2690 | scbits = sccipher_tobe->keylen; |
2691 | nbits = (csbits > scbits ? csbits : scbits); |
2692 | } |
2693 | /* The keys only have 160-bit entropy, since they're based on |
2694 | * a SHA-1 hash. So cap the key size at 160 bits. */ |
2695 | if (nbits > 160) nbits = 160; |
2696 | |
2697 | /* |
a92dd380 |
2698 | * If we're doing Diffie-Hellman group exchange, start by |
2699 | * requesting a group. |
e5574168 |
2700 | */ |
a92dd380 |
2701 | if (kex == &ssh_diffiehellman_gex) { |
a92dd380 |
2702 | logevent("Doing Diffie-Hellman group exchange"); |
2703 | /* |
7bd5a860 |
2704 | * Work out how big a DH group we will need to allow that |
2705 | * much data. |
2706 | */ |
2707 | pbits = 512 << ((nbits-1) / 64); |
a92dd380 |
2708 | ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST); |
7bd5a860 |
2709 | ssh2_pkt_adduint32(pbits); |
a92dd380 |
2710 | ssh2_pkt_send(); |
2711 | |
2712 | crWaitUntil(ispkt); |
2713 | if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) { |
2714 | bombout(("expected key exchange group packet from server")); |
2715 | crReturn(0); |
2716 | } |
2717 | p = ssh2_pkt_getmp(); |
2718 | g = ssh2_pkt_getmp(); |
2719 | dh_setup_group(p, g); |
2720 | kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT; |
2721 | kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY; |
2722 | } else { |
2723 | dh_setup_group1(); |
2724 | kex_init_value = SSH2_MSG_KEXDH_INIT; |
2725 | kex_reply_value = SSH2_MSG_KEXDH_REPLY; |
8d5de777 |
2726 | } |
e5574168 |
2727 | |
a92dd380 |
2728 | logevent("Doing Diffie-Hellman key exchange"); |
e5574168 |
2729 | /* |
a92dd380 |
2730 | * Now generate and send e for Diffie-Hellman. |
e5574168 |
2731 | */ |
7bd5a860 |
2732 | e = dh_create_e(nbits*2); |
a92dd380 |
2733 | ssh2_pkt_init(kex_init_value); |
e5574168 |
2734 | ssh2_pkt_addmp(e); |
2735 | ssh2_pkt_send(); |
2736 | |
2737 | crWaitUntil(ispkt); |
a92dd380 |
2738 | if (pktin.type != kex_reply_value) { |
2739 | bombout(("expected key exchange reply packet from server")); |
8d5de777 |
2740 | crReturn(0); |
7cca0d81 |
2741 | } |
e5574168 |
2742 | ssh2_pkt_getstring(&hostkeydata, &hostkeylen); |
2743 | f = ssh2_pkt_getmp(); |
e5574168 |
2744 | ssh2_pkt_getstring(&sigdata, &siglen); |
2745 | |
2746 | K = dh_find_K(f); |
e5574168 |
2747 | |
2748 | sha_string(&exhash, hostkeydata, hostkeylen); |
a92dd380 |
2749 | if (kex == &ssh_diffiehellman_gex) { |
7bd5a860 |
2750 | sha_uint32(&exhash, pbits); |
a92dd380 |
2751 | sha_mpint(&exhash, p); |
2752 | sha_mpint(&exhash, g); |
2753 | } |
e5574168 |
2754 | sha_mpint(&exhash, e); |
2755 | sha_mpint(&exhash, f); |
2756 | sha_mpint(&exhash, K); |
2757 | SHA_Final(&exhash, exchange_hash); |
2758 | |
3709bfe9 |
2759 | dh_cleanup(); |
2760 | |
7cca0d81 |
2761 | #if 0 |
765c4200 |
2762 | debug(("Exchange hash is:\n")); |
2763 | dmemdump(exchange_hash, 20); |
7cca0d81 |
2764 | #endif |
2765 | |
e055a386 |
2766 | hkey = hostkey->newkey(hostkeydata, hostkeylen); |
2767 | if (!hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) { |
8d5de777 |
2768 | bombout(("Server failed host key check")); |
2769 | crReturn(0); |
2770 | } |
e5574168 |
2771 | |
2772 | /* |
7cca0d81 |
2773 | * Expect SSH2_MSG_NEWKEYS from server. |
d39f364a |
2774 | */ |
7cca0d81 |
2775 | crWaitUntil(ispkt); |
8d5de777 |
2776 | if (pktin.type != SSH2_MSG_NEWKEYS) { |
2777 | bombout(("expected new-keys packet from server")); |
2778 | crReturn(0); |
2779 | } |
d39f364a |
2780 | |
2781 | /* |
7cca0d81 |
2782 | * Authenticate remote host: verify host key. (We've already |
2783 | * checked the signature of the exchange hash.) |
e5574168 |
2784 | */ |
e055a386 |
2785 | keystr = hostkey->fmtkey(hkey); |
2786 | fingerprint = hostkey->fingerprint(hkey); |
d4857987 |
2787 | verify_ssh_host_key(savedhost, savedport, hostkey->keytype, |
2788 | keystr, fingerprint); |
a92dd380 |
2789 | if (first_kex) { /* don't bother logging this in rekeys */ |
5e0d7cb8 |
2790 | logevent("Host key fingerprint is:"); |
2791 | logevent(fingerprint); |
2792 | } |
dcbde236 |
2793 | sfree(fingerprint); |
2794 | sfree(keystr); |
e055a386 |
2795 | hostkey->freekey(hkey); |
d39f364a |
2796 | |
2797 | /* |
7cca0d81 |
2798 | * Send SSH2_MSG_NEWKEYS. |
d39f364a |
2799 | */ |
2800 | ssh2_pkt_init(SSH2_MSG_NEWKEYS); |
2801 | ssh2_pkt_send(); |
d39f364a |
2802 | |
2803 | /* |
2804 | * Create and initialise session keys. |
2805 | */ |
2806 | cscipher = cscipher_tobe; |
2807 | sccipher = sccipher_tobe; |
2808 | csmac = csmac_tobe; |
2809 | scmac = scmac_tobe; |
2810 | cscomp = cscomp_tobe; |
2811 | sccomp = sccomp_tobe; |
4ba9b64b |
2812 | cscomp->compress_init(); |
2813 | sccomp->decompress_init(); |
d39f364a |
2814 | /* |
5e0d7cb8 |
2815 | * Set IVs after keys. Here we use the exchange hash from the |
2816 | * _first_ key exchange. |
d39f364a |
2817 | */ |
5e0d7cb8 |
2818 | if (first_kex) |
65a22376 |
2819 | memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash)); |
2820 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace); |
5e0d7cb8 |
2821 | cscipher->setcskey(keyspace); |
65a22376 |
2822 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace); |
5e0d7cb8 |
2823 | sccipher->setsckey(keyspace); |
65a22376 |
2824 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace); |
5e0d7cb8 |
2825 | cscipher->setcsiv(keyspace); |
65a22376 |
2826 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace); |
5e0d7cb8 |
2827 | sccipher->setsciv(keyspace); |
65a22376 |
2828 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace); |
5e0d7cb8 |
2829 | csmac->setcskey(keyspace); |
65a22376 |
2830 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace); |
5e0d7cb8 |
2831 | scmac->setsckey(keyspace); |
d39f364a |
2832 | |
033b4cef |
2833 | /* |
0db56f73 |
2834 | * If this is the first key exchange phase, we must pass the |
2835 | * SSH2_MSG_NEWKEYS packet to the next layer, not because it |
2836 | * wants to see it but because it will need time to initialise |
2837 | * itself before it sees an actual packet. In subsequent key |
2838 | * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because |
2839 | * it would only confuse the layer above. |
2840 | */ |
2841 | if (!first_kex) { |
2842 | crReturn(0); |
2843 | } |
2844 | first_kex = 0; |
2845 | |
2846 | /* |
7cca0d81 |
2847 | * Now we're encrypting. Begin returning 1 to the protocol main |
2848 | * function so that other things can run on top of the |
2849 | * transport. If we ever see a KEXINIT, we must go back to the |
2850 | * start. |
033b4cef |
2851 | */ |
e96adf72 |
2852 | while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) { |
7cca0d81 |
2853 | crReturn(1); |
e96adf72 |
2854 | } |
5e0d7cb8 |
2855 | logevent("Server initiated key re-exchange"); |
7cca0d81 |
2856 | goto begin_key_exchange; |
e5574168 |
2857 | |
2858 | crFinish(1); |
2859 | } |
2860 | |
7cca0d81 |
2861 | /* |
783415f8 |
2862 | * Add data to an SSH2 channel output buffer. |
2863 | */ |
2864 | static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len) { |
2865 | if (c->v2.outbufsize < |
2866 | c->v2.outbuflen + len) { |
2867 | c->v2.outbufsize = |
2868 | c->v2.outbuflen + len + 1024; |
2869 | c->v2.outbuffer = srealloc(c->v2.outbuffer, |
2870 | c->v2.outbufsize); |
2871 | } |
2872 | memcpy(c->v2.outbuffer + c->v2.outbuflen, |
2873 | buf, len); |
2874 | c->v2.outbuflen += len; |
2875 | } |
2876 | |
2877 | /* |
2878 | * Attempt to send data on an SSH2 channel. |
2879 | */ |
2880 | static void ssh2_try_send(struct ssh_channel *c) { |
2881 | while (c->v2.remwindow > 0 && |
2882 | c->v2.outbuflen > 0) { |
2883 | unsigned len = c->v2.remwindow; |
2884 | if (len > c->v2.outbuflen) |
2885 | len = c->v2.outbuflen; |
2886 | if (len > c->v2.remmaxpkt) |
2887 | len = c->v2.remmaxpkt; |
2888 | ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA); |
2889 | ssh2_pkt_adduint32(c->remoteid); |
2890 | ssh2_pkt_addstring_start(); |
2891 | ssh2_pkt_addstring_data(c->v2.outbuffer, len); |
2892 | ssh2_pkt_send(); |
2893 | c->v2.outbuflen -= len; |
2894 | memmove(c->v2.outbuffer, c->v2.outbuffer+len, |
2895 | c->v2.outbuflen); |
2896 | c->v2.remwindow -= len; |
2897 | } |
2898 | } |
2899 | |
2900 | /* |
7cca0d81 |
2901 | * Handle the SSH2 userauth and connection layers. |
2902 | */ |
2903 | static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) |
2904 | { |
7cca0d81 |
2905 | static unsigned long remote_winsize; |
2906 | static unsigned long remote_maxpkt; |
65a22376 |
2907 | static enum { |
2908 | AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE, AUTH_PASSWORD |
2909 | } method; |
1408a877 |
2910 | static enum { |
2911 | AUTH_TYPE_NONE, |
2912 | AUTH_TYPE_PUBLICKEY, |
2913 | AUTH_TYPE_PUBLICKEY_OFFER_LOUD, |
2914 | AUTH_TYPE_PUBLICKEY_OFFER_QUIET, |
2915 | AUTH_TYPE_PASSWORD |
2916 | } type; |
1983e559 |
2917 | static int gotit, need_pw, can_pubkey, can_passwd; |
2918 | static int tried_pubkey_config, tried_agent; |
1408a877 |
2919 | static int we_are_in; |
65a22376 |
2920 | static char username[100]; |
2921 | static char pwprompt[200]; |
2922 | static char password[100]; |
7cca0d81 |
2923 | |
e5574168 |
2924 | crBegin; |
2925 | |
7cca0d81 |
2926 | /* |
2927 | * Request userauth protocol, and await a response to it. |
2928 | */ |
2929 | ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST); |
2930 | ssh2_pkt_addstring("ssh-userauth"); |
2931 | ssh2_pkt_send(); |
2932 | crWaitUntilV(ispkt); |
8d5de777 |
2933 | if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) { |
2934 | bombout(("Server refused user authentication protocol")); |
2935 | crReturnV; |
2936 | } |
7cca0d81 |
2937 | |
2938 | /* |
1408a877 |
2939 | * We repeat this whole loop, including the username prompt, |
2940 | * until we manage a successful authentication. If the user |
2941 | * types the wrong _password_, they are sent back to the |
2942 | * beginning to try another username. (If they specify a |
2943 | * username in the config, they are never asked, even if they |
2944 | * do give a wrong password.) |
2945 | * |
2946 | * I think this best serves the needs of |
2947 | * |
2948 | * - the people who have no configuration, no keys, and just |
2949 | * want to try repeated (username,password) pairs until they |
2950 | * type both correctly |
2951 | * |
2952 | * - people who have keys and configuration but occasionally |
2953 | * need to fall back to passwords |
2954 | * |
2955 | * - people with a key held in Pageant, who might not have |
2956 | * logged in to a particular machine before; so they want to |
2957 | * type a username, and then _either_ their key will be |
2958 | * accepted, _or_ they will type a password. If they mistype |
2959 | * the username they will want to be able to get back and |
2960 | * retype it! |
7cca0d81 |
2961 | */ |
1408a877 |
2962 | do { |
2963 | static int pos; |
7cca0d81 |
2964 | static char c; |
e5574168 |
2965 | |
1408a877 |
2966 | /* |
2967 | * Get a username. |
2968 | */ |
2969 | pos = 0; |
67779be7 |
2970 | if ((flags & FLAG_INTERACTIVE) && !*cfg.username) { |
fa17a66e |
2971 | if (ssh_get_line) { |
2972 | if (!ssh_get_line("login as: ", |
2973 | username, sizeof(username), FALSE)) { |
2974 | /* |
2975 | * get_line failed to get a username. |
2976 | * Terminate. |
2977 | */ |
2978 | logevent("No username provided. Abandoning session."); |
2979 | ssh_state = SSH_STATE_CLOSED; |
dae2b91f |
2980 | crReturnV; |
fa17a66e |
2981 | } |
2982 | } else { |
2983 | c_write_str("login as: "); |
2984 | ssh_send_ok = 1; |
2985 | while (pos >= 0) { |
2986 | crWaitUntilV(!ispkt); |
2987 | while (inlen--) switch (c = *in++) { |
2988 | case 10: case 13: |
2989 | username[pos] = 0; |
2990 | pos = -1; |
2991 | break; |
2992 | case 8: case 127: |
2993 | if (pos > 0) { |
2994 | c_write_str("\b \b"); |
2995 | pos--; |
2996 | } |
2997 | break; |
2998 | case 21: case 27: |
2999 | while (pos > 0) { |
3000 | c_write_str("\b \b"); |
3001 | pos--; |
3002 | } |
3003 | break; |
3004 | case 3: case 4: |
3005 | random_save_seed(); |
3006 | exit(0); |
3007 | break; |
3008 | default: |
3009 | if (((c >= ' ' && c <= '~') || |
3010 | ((unsigned char)c >= 160)) && pos < 40) { |
3011 | username[pos++] = c; |
3012 | c_write(&c, 1); |
3013 | } |
3014 | break; |
3015 | } |
3016 | } |
3017 | } |
1408a877 |
3018 | c_write_str("\r\n"); |
7cca0d81 |
3019 | username[strcspn(username, "\n\r")] = '\0'; |
3020 | } else { |
3021 | char stuff[200]; |
3022 | strncpy(username, cfg.username, 99); |
3023 | username[99] = '\0'; |
65a22376 |
3024 | if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) { |
7cca0d81 |
3025 | sprintf(stuff, "Using username \"%s\".\r\n", username); |
1408a877 |
3026 | c_write_str(stuff); |
7cca0d81 |
3027 | } |
3028 | } |
3029 | |
65a22376 |
3030 | /* |
1408a877 |
3031 | * Send an authentication request using method "none": (a) |
3032 | * just in case it succeeds, and (b) so that we know what |
3033 | * authentication methods we can usefully try next. |
65a22376 |
3034 | */ |
1408a877 |
3035 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
3036 | ssh2_pkt_addstring(username); |
3037 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
3038 | ssh2_pkt_addstring("none"); /* method */ |
3039 | ssh2_pkt_send(); |
3040 | type = AUTH_TYPE_NONE; |
3041 | gotit = FALSE; |
3042 | we_are_in = FALSE; |
7cca0d81 |
3043 | |
1408a877 |
3044 | tried_pubkey_config = FALSE; |
1983e559 |
3045 | tried_agent = FALSE; |
65a22376 |
3046 | |
1408a877 |
3047 | while (1) { |
3048 | /* |
3049 | * Wait for the result of the last authentication request. |
3050 | */ |
3051 | if (!gotit) |
3052 | crWaitUntilV(ispkt); |
3053 | while (pktin.type == SSH2_MSG_USERAUTH_BANNER) { |
a209e957 |
3054 | char *banner; |
3055 | int size; |
10446215 |
3056 | /* |
3057 | * Don't show the banner if we're operating in |
3058 | * non-verbose non-interactive mode. (It's probably |
3059 | * a script, which means nobody will read the |
3060 | * banner _anyway_, and moreover the printing of |
3061 | * the banner will screw up processing on the |
3062 | * output of (say) plink.) |
3063 | */ |
3064 | if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) { |
3065 | ssh2_pkt_getstring(&banner, &size); |
3066 | if (banner) |
3067 | c_write_untrusted(banner, size); |
3068 | } |
1408a877 |
3069 | crWaitUntilV(ispkt); |
3070 | } |
3071 | if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) { |
3072 | logevent("Access granted"); |
3073 | we_are_in = TRUE; |
3074 | break; |
3075 | } |
65a22376 |
3076 | |
1408a877 |
3077 | if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) { |
3078 | bombout(("Strange packet received during authentication: type %d", |
3079 | pktin.type)); |
38c4a8da |
3080 | crReturnV; |
65a22376 |
3081 | } |
3082 | |
1408a877 |
3083 | gotit = FALSE; |
65a22376 |
3084 | |
1408a877 |
3085 | /* |
3086 | * OK, we're now sitting on a USERAUTH_FAILURE message, so |
3087 | * we can look at the string in it and know what we can |
3088 | * helpfully try next. |
3089 | */ |
3090 | { |
3091 | char *methods; |
3092 | int methlen; |
3093 | ssh2_pkt_getstring(&methods, &methlen); |
3094 | if (!ssh2_pkt_getbool()) { |
3095 | /* |
3096 | * We have received an unequivocal Access |
3097 | * Denied. This can translate to a variety of |
3098 | * messages: |
3099 | * |
3100 | * - if we'd just tried "none" authentication, |
3101 | * it's not worth printing anything at all |
3102 | * |
3103 | * - if we'd just tried a public key _offer_, |
3104 | * the message should be "Server refused our |
3105 | * key" (or no message at all if the key |
3106 | * came from Pageant) |
3107 | * |
3108 | * - if we'd just tried anything else, the |
3109 | * message really should be "Access denied". |
3110 | * |
3111 | * Additionally, if we'd just tried password |
3112 | * authentication, we should break out of this |
3113 | * whole loop so as to go back to the username |
3114 | * prompt. |
3115 | */ |
3116 | if (type == AUTH_TYPE_NONE) { |
3117 | /* do nothing */ |
3118 | } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD || |
3119 | type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) { |
3120 | if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD) |
3121 | c_write_str("Server refused our key\r\n"); |
3122 | logevent("Server refused public key"); |
3123 | } else { |
3124 | c_write_str("Access denied\r\n"); |
3125 | logevent("Access denied"); |
3126 | if (type == AUTH_TYPE_PASSWORD) { |
3127 | we_are_in = FALSE; |
3128 | break; |
3129 | } |
3130 | } |
3131 | } else { |
3132 | c_write_str("Further authentication required\r\n"); |
3133 | logevent("Further authentication required"); |
3134 | } |
65a22376 |
3135 | |
1408a877 |
3136 | can_pubkey = in_commasep_string("publickey", methods, methlen); |
3137 | can_passwd = in_commasep_string("password", methods, methlen); |
3138 | } |
65a22376 |
3139 | |
1408a877 |
3140 | method = 0; |
65a22376 |
3141 | |
78afa559 |
3142 | if (!method && can_pubkey && agent_exists() && !tried_agent) { |
1983e559 |
3143 | /* |
3144 | * Attempt public-key authentication using Pageant. |
3145 | */ |
3146 | static unsigned char request[5], *response, *p; |
3147 | static int responselen; |
3148 | static int i, nkeys; |
3149 | static int authed = FALSE; |
3150 | void *r; |
3151 | |
3152 | tried_agent = TRUE; |
3153 | |
3154 | logevent("Pageant is running. Requesting keys."); |
3155 | |
3156 | /* Request the keys held by the agent. */ |
3157 | PUT_32BIT(request, 1); |
3158 | request[4] = SSH2_AGENTC_REQUEST_IDENTITIES; |
3159 | agent_query(request, 5, &r, &responselen); |
3160 | response = (unsigned char *)r; |
95797139 |
3161 | if (response && responselen >= 5 && |
3162 | response[4] == SSH2_AGENT_IDENTITIES_ANSWER) { |
1983e559 |
3163 | p = response + 5; |
3164 | nkeys = GET_32BIT(p); p += 4; |
6328ea7a |
3165 | { char buf[64]; sprintf(buf, "Pageant has %d SSH2 keys", nkeys); |
1983e559 |
3166 | logevent(buf); } |
3167 | for (i = 0; i < nkeys; i++) { |
3168 | static char *pkblob, *alg, *commentp; |
3169 | static int pklen, alglen, commentlen; |
3170 | static int siglen, retlen, len; |
3171 | static char *q, *agentreq, *ret; |
3172 | |
3173 | { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i); |
3174 | logevent(buf); } |
3175 | pklen = GET_32BIT(p); p += 4; |
3176 | pkblob = p; p += pklen; |
3177 | alglen = GET_32BIT(pkblob); |
3178 | alg = pkblob + 4; |
3179 | commentlen = GET_32BIT(p); p += 4; |
3180 | commentp = p; p += commentlen; |
3181 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
3182 | ssh2_pkt_addstring(username); |
3183 | ssh2_pkt_addstring("ssh-connection");/* service requested */ |
3184 | ssh2_pkt_addstring("publickey");/* method */ |
3185 | ssh2_pkt_addbool(FALSE); /* no signature included */ |
3186 | ssh2_pkt_addstring_start(); |
3187 | ssh2_pkt_addstring_data(alg, alglen); |
3188 | ssh2_pkt_addstring_start(); |
3189 | ssh2_pkt_addstring_data(pkblob, pklen); |
3190 | ssh2_pkt_send(); |
3191 | |
3192 | crWaitUntilV(ispkt); |
3193 | if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) { |
3194 | logevent("Key refused"); |
3195 | continue; |
3196 | } |
3197 | |
10446215 |
3198 | if (flags & FLAG_VERBOSE) { |
3199 | c_write_str("Authenticating with public key \""); |
3200 | c_write(commentp, commentlen); |
3201 | c_write_str("\" from agent\r\n"); |
3202 | } |
1983e559 |
3203 | |
3204 | /* |
3205 | * Server is willing to accept the key. |
3206 | * Construct a SIGN_REQUEST. |
3207 | */ |
3208 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
3209 | ssh2_pkt_addstring(username); |
3210 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
3211 | ssh2_pkt_addstring("publickey"); /* method */ |
3212 | ssh2_pkt_addbool(TRUE); |
3213 | ssh2_pkt_addstring_start(); |
3214 | ssh2_pkt_addstring_data(alg, alglen); |
3215 | ssh2_pkt_addstring_start(); |
3216 | ssh2_pkt_addstring_data(pkblob, pklen); |
3217 | |
3218 | siglen = pktout.length - 5 + 4 + 20; |
3219 | len = 1; /* message type */ |
3220 | len += 4 + pklen; /* key blob */ |
3221 | len += 4 + siglen; /* data to sign */ |
3222 | len += 4; /* flags */ |
3223 | agentreq = smalloc(4 + len); |
3224 | PUT_32BIT(agentreq, len); |
3225 | q = agentreq + 4; |
3226 | *q++ = SSH2_AGENTC_SIGN_REQUEST; |
3227 | PUT_32BIT(q, pklen); q += 4; |
3228 | memcpy(q, pkblob, pklen); q += pklen; |
3229 | PUT_32BIT(q, siglen); q += 4; |
3230 | /* Now the data to be signed... */ |
3231 | PUT_32BIT(q, 20); q += 4; |
3232 | memcpy(q, ssh2_session_id, 20); q += 20; |
3233 | memcpy(q, pktout.data+5, pktout.length-5); |
3234 | q += pktout.length-5; |
3235 | /* And finally the (zero) flags word. */ |
3236 | PUT_32BIT(q, 0); |
3237 | agent_query(agentreq, len+4, &ret, &retlen); |
3238 | sfree(agentreq); |
3239 | if (ret) { |
3240 | if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) { |
3241 | logevent("Sending Pageant's response"); |
3242 | ssh2_pkt_addstring_start(); |
3243 | ssh2_pkt_addstring_data(ret+9, GET_32BIT(ret+5)); |
3244 | ssh2_pkt_send(); |
3245 | authed = TRUE; |
3246 | break; |
3247 | } else { |
3248 | logevent("Pageant failed to answer challenge"); |
3249 | sfree(ret); |
3250 | } |
3251 | } |
3252 | } |
3253 | if (authed) |
3254 | continue; |
3255 | } |
3256 | } |
3257 | |
1408a877 |
3258 | if (!method && can_pubkey && *cfg.keyfile && !tried_pubkey_config) { |
3259 | unsigned char *pub_blob; |
3260 | char *algorithm, *comment; |
3261 | int pub_blob_len; |
65a22376 |
3262 | |
1408a877 |
3263 | tried_pubkey_config = TRUE; |
65a22376 |
3264 | |
65a22376 |
3265 | /* |
1408a877 |
3266 | * Try the public key supplied in the configuration. |
3267 | * |
3268 | * First, offer the public blob to see if the server is |
3269 | * willing to accept it. |
65a22376 |
3270 | */ |
1408a877 |
3271 | pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm, |
3272 | &pub_blob_len); |
3273 | if (pub_blob) { |
3274 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
3275 | ssh2_pkt_addstring(username); |
3276 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
3277 | ssh2_pkt_addstring("publickey");/* method */ |
3278 | ssh2_pkt_addbool(FALSE); /* no signature included */ |
3279 | ssh2_pkt_addstring(algorithm); |
3280 | ssh2_pkt_addstring_start(); |
3281 | ssh2_pkt_addstring_data(pub_blob, pub_blob_len); |
3282 | ssh2_pkt_send(); |
3283 | logevent("Offered public key"); /* FIXME */ |
3284 | |
3285 | crWaitUntilV(ispkt); |
3286 | if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) { |
3287 | gotit = TRUE; |
3288 | type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD; |
3289 | continue; /* key refused; give up on it */ |
3290 | } |
65a22376 |
3291 | |
1408a877 |
3292 | logevent("Offer of public key accepted"); |
65a22376 |
3293 | /* |
1408a877 |
3294 | * Actually attempt a serious authentication using |
3295 | * the key. |
65a22376 |
3296 | */ |
1408a877 |
3297 | if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) { |
3298 | sprintf(pwprompt, "Passphrase for key \"%.100s\": ", comment); |
3299 | need_pw = TRUE; |
3300 | } else { |
3301 | need_pw = FALSE; |
3302 | } |
3303 | c_write_str("Authenticating with public key \""); |
3304 | c_write_str(comment); |
3305 | c_write_str("\"\r\n"); |
3306 | method = AUTH_PUBLICKEY_FILE; |
65a22376 |
3307 | } |
1408a877 |
3308 | } |
3309 | |
3310 | if (!method && can_passwd) { |
3311 | method = AUTH_PASSWORD; |
3312 | sprintf(pwprompt, "%.90s@%.90s's password: ", username, savedhost); |
3313 | need_pw = TRUE; |
3314 | } |
3315 | |
3316 | if (need_pw) { |
fa17a66e |
3317 | if (ssh_get_line) { |
3318 | if (!ssh_get_line(pwprompt, password, |
3319 | sizeof(password), TRUE)) { |
1408a877 |
3320 | /* |
fa17a66e |
3321 | * get_line failed to get a password (for |
3322 | * example because one was supplied on the |
3323 | * command line which has already failed to |
3324 | * work). Terminate. |
1408a877 |
3325 | */ |
3326 | logevent("No more passwords to try"); |
3327 | ssh_state = SSH_STATE_CLOSED; |
3328 | crReturnV; |
3329 | } |
3330 | } else { |
3331 | static int pos = 0; |
3332 | static char c; |
3333 | |
3334 | c_write_str(pwprompt); |
3335 | ssh_send_ok = 1; |
3336 | |
3337 | pos = 0; |
3338 | while (pos >= 0) { |
3339 | crWaitUntilV(!ispkt); |
3340 | while (inlen--) switch (c = *in++) { |
3341 | case 10: case 13: |
3342 | password[pos] = 0; |
3343 | pos = -1; |
3344 | break; |
3345 | case 8: case 127: |
3346 | if (pos > 0) |
3347 | pos--; |
3348 | break; |
3349 | case 21: case 27: |
3350 | pos = 0; |
3351 | break; |
3352 | case 3: case 4: |
3353 | random_save_seed(); |
3354 | exit(0); |
3355 | break; |
3356 | default: |
3357 | if (((c >= ' ' && c <= '~') || |
3358 | ((unsigned char)c >= 160)) && pos < 40) |
3359 | password[pos++] = c; |
3360 | break; |
3361 | } |
65a22376 |
3362 | } |
1408a877 |
3363 | c_write_str("\r\n"); |
65a22376 |
3364 | } |
65a22376 |
3365 | } |
65a22376 |
3366 | |
1408a877 |
3367 | if (method == AUTH_PUBLICKEY_FILE) { |
3368 | /* |
3369 | * We have our passphrase. Now try the actual authentication. |
3370 | */ |
3371 | struct ssh2_userkey *key; |
65a22376 |
3372 | |
1408a877 |
3373 | key = ssh2_load_userkey(cfg.keyfile, password); |
3374 | if (key == SSH2_WRONG_PASSPHRASE || key == NULL) { |
3375 | if (key == SSH2_WRONG_PASSPHRASE) { |
3376 | c_write_str("Wrong passphrase\r\n"); |
3377 | tried_pubkey_config = FALSE; |
3378 | } else { |
3379 | c_write_str("Unable to load private key\r\n"); |
3380 | tried_pubkey_config = TRUE; |
3381 | } |
3382 | /* Send a spurious AUTH_NONE to return to the top. */ |
3383 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
3384 | ssh2_pkt_addstring(username); |
3385 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
3386 | ssh2_pkt_addstring("none"); /* method */ |
3387 | ssh2_pkt_send(); |
3388 | type = AUTH_TYPE_NONE; |
3389 | } else { |
3390 | unsigned char *blob, *sigdata; |
3391 | int blob_len, sigdata_len; |
65a22376 |
3392 | |
1408a877 |
3393 | /* |
3394 | * We have loaded the private key and the server |
3395 | * has announced that it's willing to accept it. |
3396 | * Hallelujah. Generate a signature and send it. |
3397 | */ |
3398 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
3399 | ssh2_pkt_addstring(username); |
3400 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
3401 | ssh2_pkt_addstring("publickey"); /* method */ |
3402 | ssh2_pkt_addbool(TRUE); |
3403 | ssh2_pkt_addstring(key->alg->name); |
3404 | blob = key->alg->public_blob(key->data, &blob_len); |
3405 | ssh2_pkt_addstring_start(); |
3406 | ssh2_pkt_addstring_data(blob, blob_len); |
3407 | sfree(blob); |
3408 | |
3409 | /* |
3410 | * The data to be signed is: |
3411 | * |
3412 | * string session-id |
3413 | * |
3414 | * followed by everything so far placed in the |
3415 | * outgoing packet. |
3416 | */ |
3417 | sigdata_len = pktout.length - 5 + 4 + 20; |
3418 | sigdata = smalloc(sigdata_len); |
3419 | PUT_32BIT(sigdata, 20); |
3420 | memcpy(sigdata+4, ssh2_session_id, 20); |
3421 | memcpy(sigdata+24, pktout.data+5, pktout.length-5); |
3422 | blob = key->alg->sign(key->data, sigdata, sigdata_len, &blob_len); |
3423 | ssh2_pkt_addstring_start(); |
3424 | ssh2_pkt_addstring_data(blob, blob_len); |
3425 | sfree(blob); |
3426 | sfree(sigdata); |
3427 | |
3428 | ssh2_pkt_send(); |
3429 | type = AUTH_TYPE_PUBLICKEY; |
3430 | } |
3431 | } else if (method == AUTH_PASSWORD) { |
65a22376 |
3432 | /* |
1408a877 |
3433 | * We send the password packet lumped tightly together with |
3434 | * an SSH_MSG_IGNORE packet. The IGNORE packet contains a |
3435 | * string long enough to make the total length of the two |
3436 | * packets constant. This should ensure that a passive |
3437 | * listener doing traffic analyis can't work out the length |
3438 | * of the password. |
3439 | * |
3440 | * For this to work, we need an assumption about the |
3441 | * maximum length of the password packet. I think 256 is |
3442 | * pretty conservative. Anyone using a password longer than |
3443 | * that probably doesn't have much to worry about from |
3444 | * people who find out how long their password is! |
65a22376 |
3445 | */ |
3446 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
3447 | ssh2_pkt_addstring(username); |
3448 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
1408a877 |
3449 | ssh2_pkt_addstring("password"); |
3450 | ssh2_pkt_addbool(FALSE); |
3451 | ssh2_pkt_addstring(password); |
3452 | ssh2_pkt_defer(); |
65a22376 |
3453 | /* |
1408a877 |
3454 | * We'll include a string that's an exact multiple of the |
3455 | * cipher block size. If the cipher is NULL for some |
3456 | * reason, we don't do this trick at all because we gain |
3457 | * nothing by it. |
65a22376 |
3458 | */ |
6e9e9520 |
3459 | if (cscipher) { |
3460 | int stringlen, i; |
3461 | |
3462 | stringlen = (256 - deferred_len); |
3463 | stringlen += cscipher->blksize - 1; |
3464 | stringlen -= (stringlen % cscipher->blksize); |
3465 | if (cscomp) { |
3466 | /* |
3467 | * Temporarily disable actual compression, |
3468 | * so we can guarantee to get this string |
3469 | * exactly the length we want it. The |
3470 | * compression-disabling routine should |
3471 | * return an integer indicating how many |
3472 | * bytes we should adjust our string length |
3473 | * by. |
3474 | */ |
3475 | stringlen -= cscomp->disable_compression(); |
3476 | } |
1408a877 |
3477 | ssh2_pkt_init(SSH2_MSG_IGNORE); |
3478 | ssh2_pkt_addstring_start(); |
6e9e9520 |
3479 | for (i = 0; i < stringlen; i++) { |
3480 | char c = (char)random_byte(); |
3481 | ssh2_pkt_addstring_data(&c, 1); |
65a22376 |
3482 | } |
1408a877 |
3483 | ssh2_pkt_defer(); |
65a22376 |
3484 | } |
39065bed |
3485 | ssh_pkt_defersend(); |
0d43337a |
3486 | logevent("Sent password"); |
1408a877 |
3487 | type = AUTH_TYPE_PASSWORD; |
3488 | } else { |
3489 | c_write_str("No supported authentication methods left to try!\r\n"); |
3490 | logevent("No supported authentications offered. Disconnecting"); |
3491 | ssh2_pkt_init(SSH2_MSG_DISCONNECT); |
3492 | ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION); |
3493 | ssh2_pkt_addstring("No supported authentication methods available"); |
3494 | ssh2_pkt_addstring("en"); /* language tag */ |
3495 | ssh2_pkt_send(); |
3496 | ssh_state = SSH_STATE_CLOSED; |
3497 | crReturnV; |
65a22376 |
3498 | } |
65a22376 |
3499 | } |
1408a877 |
3500 | } while (!we_are_in); |
7cca0d81 |
3501 | |
3502 | /* |
3503 | * Now we're authenticated for the connection protocol. The |
3504 | * connection protocol will automatically have started at this |
3505 | * point; there's no need to send SERVICE_REQUEST. |
3506 | */ |
3507 | |
3508 | /* |
3509 | * So now create a channel with a session in it. |
3510 | */ |
d2371c81 |
3511 | ssh_channels = newtree234(ssh_channelcmp); |
dcbde236 |
3512 | mainchan = smalloc(sizeof(struct ssh_channel)); |
d2371c81 |
3513 | mainchan->localid = alloc_channel_id(); |
7cca0d81 |
3514 | ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN); |
3515 | ssh2_pkt_addstring("session"); |
d211621f |
3516 | ssh2_pkt_adduint32(mainchan->localid); |
cf6e59d6 |
3517 | ssh2_pkt_adduint32(0x8000UL); /* our window size */ |
d211621f |
3518 | ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */ |
7cca0d81 |
3519 | ssh2_pkt_send(); |
3520 | crWaitUntilV(ispkt); |
3521 | if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) { |
8d5de777 |
3522 | bombout(("Server refused to open a session")); |
3523 | crReturnV; |
7cca0d81 |
3524 | /* FIXME: error data comes back in FAILURE packet */ |
3525 | } |
d211621f |
3526 | if (ssh2_pkt_getuint32() != mainchan->localid) { |
8d5de777 |
3527 | bombout(("Server's channel confirmation cited wrong channel")); |
3528 | crReturnV; |
7cca0d81 |
3529 | } |
d211621f |
3530 | mainchan->remoteid = ssh2_pkt_getuint32(); |
783415f8 |
3531 | mainchan->type = CHAN_MAINSESSION; |
3532 | mainchan->closes = 0; |
3533 | mainchan->v2.remwindow = ssh2_pkt_getuint32(); |
3534 | mainchan->v2.remmaxpkt = ssh2_pkt_getuint32(); |
3535 | mainchan->v2.outbuffer = NULL; |
3536 | mainchan->v2.outbuflen = mainchan->v2.outbufsize = 0; |
783415f8 |
3537 | add234(ssh_channels, mainchan); |
7cca0d81 |
3538 | logevent("Opened channel for session"); |
3539 | |
3540 | /* |
783415f8 |
3541 | * Potentially enable X11 forwarding. |
3542 | */ |
3543 | if (cfg.x11_forward) { |
3544 | char proto[20], data[64]; |
3545 | logevent("Requesting X11 forwarding"); |
3546 | x11_invent_auth(proto, sizeof(proto), data, sizeof(data)); |
3547 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
3548 | ssh2_pkt_adduint32(mainchan->remoteid); |
3549 | ssh2_pkt_addstring("x11-req"); |
3550 | ssh2_pkt_addbool(1); /* want reply */ |
3551 | ssh2_pkt_addbool(0); /* many connections */ |
3552 | ssh2_pkt_addstring(proto); |
3553 | ssh2_pkt_addstring(data); |
3554 | ssh2_pkt_adduint32(0); /* screen number */ |
3555 | ssh2_pkt_send(); |
3556 | |
3557 | do { |
3558 | crWaitUntilV(ispkt); |
3559 | if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
3560 | unsigned i = ssh2_pkt_getuint32(); |
3561 | struct ssh_channel *c; |
3562 | c = find234(ssh_channels, &i, ssh_channelfind); |
3563 | if (!c) |
3564 | continue; /* nonexistent channel */ |
3565 | c->v2.remwindow += ssh2_pkt_getuint32(); |
3566 | } |
3567 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
3568 | |
3569 | if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
3570 | if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
3571 | bombout(("Server got confused by X11 forwarding request")); |
3572 | crReturnV; |
3573 | } |
3574 | logevent("X11 forwarding refused"); |
3575 | } else { |
3576 | logevent("X11 forwarding enabled"); |
3577 | ssh_X11_fwd_enabled = TRUE; |
3578 | } |
3579 | } |
3580 | |
3581 | /* |
36c2a3e9 |
3582 | * Potentially enable agent forwarding. |
3583 | */ |
3584 | if (cfg.agentfwd && agent_exists()) { |
36c2a3e9 |
3585 | logevent("Requesting OpenSSH-style agent forwarding"); |
36c2a3e9 |
3586 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
3587 | ssh2_pkt_adduint32(mainchan->remoteid); |
3588 | ssh2_pkt_addstring("auth-agent-req@openssh.com"); |
3589 | ssh2_pkt_addbool(1); /* want reply */ |
3590 | ssh2_pkt_send(); |
3591 | |
3592 | do { |
3593 | crWaitUntilV(ispkt); |
3594 | if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
3595 | unsigned i = ssh2_pkt_getuint32(); |
3596 | struct ssh_channel *c; |
3597 | c = find234(ssh_channels, &i, ssh_channelfind); |
3598 | if (!c) |
3599 | continue; /* nonexistent channel */ |
3600 | c->v2.remwindow += ssh2_pkt_getuint32(); |
3601 | } |
3602 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
3603 | |
3604 | if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
3605 | if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
3606 | bombout(("Server got confused by agent forwarding request")); |
3607 | crReturnV; |
3608 | } |
3609 | logevent("Agent forwarding refused"); |
3610 | } else { |
3611 | logevent("Agent forwarding enabled"); |
3612 | ssh_agentfwd_enabled = TRUE; |
3613 | } |
3614 | } |
3615 | |
3616 | /* |
7cca0d81 |
3617 | * Now allocate a pty for the session. |
3618 | */ |
67779be7 |
3619 | if (!cfg.nopty) { |
3620 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
3621 | ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */ |
3622 | ssh2_pkt_addstring("pty-req"); |
3623 | ssh2_pkt_addbool(1); /* want reply */ |
3624 | ssh2_pkt_addstring(cfg.termtype); |
3625 | ssh2_pkt_adduint32(cols); |
3626 | ssh2_pkt_adduint32(rows); |
3627 | ssh2_pkt_adduint32(0); /* pixel width */ |
3628 | ssh2_pkt_adduint32(0); /* pixel height */ |
3629 | ssh2_pkt_addstring_start(); |
3630 | ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */ |
3631 | ssh2_pkt_send(); |
6e48c3fe |
3632 | ssh_state = SSH_STATE_INTERMED; |
7cca0d81 |
3633 | |
67779be7 |
3634 | do { |
3635 | crWaitUntilV(ispkt); |
3636 | if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
783415f8 |
3637 | unsigned i = ssh2_pkt_getuint32(); |
3638 | struct ssh_channel *c; |
3639 | c = find234(ssh_channels, &i, ssh_channelfind); |
3640 | if (!c) |
3641 | continue; /* nonexistent channel */ |
3642 | c->v2.remwindow += ssh2_pkt_getuint32(); |
67779be7 |
3643 | } |
3644 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
7cca0d81 |
3645 | |
67779be7 |
3646 | if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
3647 | if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
8d5de777 |
3648 | bombout(("Server got confused by pty request")); |
3649 | crReturnV; |
67779be7 |
3650 | } |
1408a877 |
3651 | c_write_str("Server refused to allocate pty\r\n"); |
0965bee0 |
3652 | ssh_editing = ssh_echoing = 1; |
67779be7 |
3653 | } else { |
3654 | logevent("Allocated pty"); |
7cca0d81 |
3655 | } |
0965bee0 |
3656 | } else { |
3657 | ssh_editing = ssh_echoing = 1; |
7cca0d81 |
3658 | } |
3659 | |
3660 | /* |
67779be7 |
3661 | * Start a shell or a remote command. |
7cca0d81 |
3662 | */ |
3663 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
d211621f |
3664 | ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */ |
4a8fc3c4 |
3665 | if (cfg.ssh_subsys) { |
3666 | ssh2_pkt_addstring("subsystem"); |
3667 | ssh2_pkt_addbool(1); /* want reply */ |
96621a84 |
3668 | ssh2_pkt_addstring(cfg.remote_cmd_ptr); |
3669 | } else if (*cfg.remote_cmd_ptr) { |
67779be7 |
3670 | ssh2_pkt_addstring("exec"); |
3671 | ssh2_pkt_addbool(1); /* want reply */ |
96621a84 |
3672 | ssh2_pkt_addstring(cfg.remote_cmd_ptr); |
67779be7 |
3673 | } else { |
3674 | ssh2_pkt_addstring("shell"); |
3675 | ssh2_pkt_addbool(1); /* want reply */ |
3676 | } |
7cca0d81 |
3677 | ssh2_pkt_send(); |
d211621f |
3678 | do { |
7cca0d81 |
3679 | crWaitUntilV(ispkt); |
d211621f |
3680 | if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
783415f8 |
3681 | unsigned i = ssh2_pkt_getuint32(); |
3682 | struct ssh_channel *c; |
3683 | c = find234(ssh_channels, &i, ssh_channelfind); |
3684 | if (!c) |
3685 | continue; /* nonexistent channel */ |
3686 | c->v2.remwindow += ssh2_pkt_getuint32(); |
d211621f |
3687 | } |
7cca0d81 |
3688 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
3689 | if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
3690 | if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
8d5de777 |
3691 | bombout(("Server got confused by shell/command request")); |
3692 | crReturnV; |
7cca0d81 |
3693 | } |
8d5de777 |
3694 | bombout(("Server refused to start a shell/command")); |
3695 | crReturnV; |
7cca0d81 |
3696 | } else { |
8d5de777 |
3697 | logevent("Started a shell/command"); |
7cca0d81 |
3698 | } |
3699 | |
6e48c3fe |
3700 | ssh_state = SSH_STATE_SESSION; |
3701 | if (size_needed) |
3702 | ssh_size(); |
3687d221 |
3703 | if (eof_needed) |
3704 | ssh_special(TS_EOF); |
6e48c3fe |
3705 | |
7cca0d81 |
3706 | /* |
3707 | * Transfer data! |
3708 | */ |
0965bee0 |
3709 | ldisc_send(NULL, 0); /* cause ldisc to notice changes */ |
8ccc75b0 |
3710 | ssh_send_ok = 1; |
7cca0d81 |
3711 | while (1) { |
d211621f |
3712 | static int try_send; |
e5574168 |
3713 | crReturnV; |
d211621f |
3714 | try_send = FALSE; |
7cca0d81 |
3715 | if (ispkt) { |
3716 | if (pktin.type == SSH2_MSG_CHANNEL_DATA || |
3717 | pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) { |
3718 | char *data; |
3719 | int length; |
783415f8 |
3720 | unsigned i = ssh2_pkt_getuint32(); |
3721 | struct ssh_channel *c; |
3722 | c = find234(ssh_channels, &i, ssh_channelfind); |
3723 | if (!c) |
3724 | continue; /* nonexistent channel */ |
7cca0d81 |
3725 | if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA && |
3726 | ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR) |
3727 | continue; /* extended but not stderr */ |
3728 | ssh2_pkt_getstring(&data, &length); |
d211621f |
3729 | if (data) { |
783415f8 |
3730 | switch (c->type) { |
3731 | case CHAN_MAINSESSION: |
3732 | from_backend(pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA, |
3733 | data, length); |
3734 | break; |
3735 | case CHAN_X11: |
3736 | x11_send(c->u.x11.s, data, length); |
3737 | break; |
36c2a3e9 |
3738 | case CHAN_AGENT: |
3739 | while (length > 0) { |
3740 | if (c->u.a.lensofar < 4) { |
3741 | int l = min(4 - c->u.a.lensofar, length); |
3742 | memcpy(c->u.a.msglen + c->u.a.lensofar, data, l); |
3743 | data += l; length -= l; c->u.a.lensofar += l; |
3744 | } |
3745 | if (c->u.a.lensofar == 4) { |
3746 | c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen); |
3747 | c->u.a.message = smalloc(c->u.a.totallen); |
3748 | memcpy(c->u.a.message, c->u.a.msglen, 4); |
3749 | } |
3750 | if (c->u.a.lensofar >= 4 && length > 0) { |
3751 | int l = min(c->u.a.totallen - c->u.a.lensofar, |
3752 | length); |
3753 | memcpy(c->u.a.message + c->u.a.lensofar, data, l); |
3754 | data += l; length -= l; c->u.a.lensofar += l; |
3755 | } |
3756 | if (c->u.a.lensofar == c->u.a.totallen) { |
3757 | void *reply, *sentreply; |
3758 | int replylen; |
3759 | agent_query(c->u.a.message, c->u.a.totallen, |
3760 | &reply, &replylen); |
3761 | if (reply) |
3762 | sentreply = reply; |
3763 | else { |
3764 | /* Fake SSH_AGENT_FAILURE. */ |
3765 | sentreply = "\0\0\0\1\5"; |
3766 | replylen = 5; |
3767 | } |
3768 | ssh2_add_channel_data(c, sentreply, replylen); |
3769 | try_send = TRUE; |
3770 | if (reply) |
3771 | sfree(reply); |
3772 | sfree(c->u.a.message); |
3773 | c->u.a.lensofar = 0; |
3774 | } |
3775 | } |
3776 | break; |
783415f8 |
3777 | } |
d211621f |
3778 | /* |
783415f8 |
3779 | * Enlarge the window again at the remote |
3780 | * side, just in case it ever runs down and |
3781 | * they fail to send us any more data. |
d211621f |
3782 | */ |
3783 | ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
783415f8 |
3784 | ssh2_pkt_adduint32(c->remoteid); |
d211621f |
3785 | ssh2_pkt_adduint32(length); |
3786 | ssh2_pkt_send(); |
3787 | } |
7cca0d81 |
3788 | } else if (pktin.type == SSH2_MSG_DISCONNECT) { |
3789 | ssh_state = SSH_STATE_CLOSED; |
d211621f |
3790 | logevent("Received disconnect message"); |
3257deae |
3791 | crReturnV; |
7cca0d81 |
3792 | } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) { |
3793 | continue; /* exit status et al; ignore (FIXME?) */ |
d211621f |
3794 | } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) { |
783415f8 |
3795 | unsigned i = ssh2_pkt_getuint32(); |
3796 | struct ssh_channel *c; |
3797 | |
3798 | c = find234(ssh_channels, &i, ssh_channelfind); |
3799 | if (!c) |
3800 | continue; /* nonexistent channel */ |
3801 | |
3802 | if (c->type == CHAN_X11) { |
3803 | /* |
3804 | * Remote EOF on an X11 channel means we should |
3805 | * wrap up and close the channel ourselves. |
3806 | */ |
3807 | x11_close(c->u.x11.s); |
3808 | sshfwd_close(c); |
36c2a3e9 |
3809 | } else if (c->type == CHAN_AGENT) { |
3810 | sshfwd_close(c); |
3811 | } |
d211621f |
3812 | } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) { |
783415f8 |
3813 | unsigned i = ssh2_pkt_getuint32(); |
3814 | struct ssh_channel *c; |
783415f8 |
3815 | |
3816 | c = find234(ssh_channels, &i, ssh_channelfind); |
3817 | if (!c) |
3818 | continue; /* nonexistent channel */ |
3819 | if (c->closes == 0) { |
3820 | ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); |
3821 | ssh2_pkt_adduint32(c->remoteid); |
3822 | ssh2_pkt_send(); |
3823 | } |
3824 | /* Do pre-close processing on the channel. */ |
3825 | switch (c->type) { |
3826 | case CHAN_MAINSESSION: |
3827 | break; /* nothing to see here, move along */ |
3828 | case CHAN_X11: |
3829 | break; |
36c2a3e9 |
3830 | case CHAN_AGENT: |
3831 | break; |
783415f8 |
3832 | } |
3833 | del234(ssh_channels, c); |
3834 | sfree(c->v2.outbuffer); |
3835 | sfree(c); |
3836 | |
3837 | /* |
3838 | * See if that was the last channel left open. |
3839 | */ |
d2371c81 |
3840 | if (count234(ssh_channels) == 0) { |
d211621f |
3841 | logevent("All channels closed. Disconnecting"); |
3842 | ssh2_pkt_init(SSH2_MSG_DISCONNECT); |
9005f3ba |
3843 | ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION); |
3844 | ssh2_pkt_addstring("All open channels closed"); |
3845 | ssh2_pkt_addstring("en"); /* language tag */ |
d211621f |
3846 | ssh2_pkt_send(); |
cf6e59d6 |
3847 | ssh_state = SSH_STATE_CLOSED; |
3257deae |
3848 | crReturnV; |
d211621f |
3849 | } |
3850 | continue; /* remote sends close; ignore (FIXME) */ |
7cca0d81 |
3851 | } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
783415f8 |
3852 | unsigned i = ssh2_pkt_getuint32(); |
3853 | struct ssh_channel *c; |
3854 | c = find234(ssh_channels, &i, ssh_channelfind); |
3855 | if (!c) |
3856 | continue; /* nonexistent channel */ |
0993479d |
3857 | c->v2.remwindow += ssh2_pkt_getuint32(); |
d211621f |
3858 | try_send = TRUE; |
783415f8 |
3859 | } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) { |
3860 | char *type; |
3861 | int typelen; |
3862 | char *error = NULL; |
3863 | struct ssh_channel *c; |
3864 | ssh2_pkt_getstring(&type, &typelen); |
3865 | c = smalloc(sizeof(struct ssh_channel)); |
3866 | |
3867 | if (typelen == 3 && !memcmp(type, "x11", 3)) { |
783415f8 |
3868 | if (!ssh_X11_fwd_enabled) |
3869 | error = "X11 forwarding is not enabled"; |
0c6c9a70 |
3870 | else if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) { |
783415f8 |
3871 | error = "Unable to open an X11 connection"; |
3872 | } else { |
3873 | c->type = CHAN_X11; |
3874 | } |
36c2a3e9 |
3875 | } else if (typelen == 22 && |
3876 | !memcmp(type, "auth-agent@openssh.com", 3)) { |
3877 | if (!ssh_agentfwd_enabled) |
3878 | error = "Agent forwarding is not enabled"; |
3879 | else { |
3880 | c->type = CHAN_AGENT; /* identify channel type */ |
3881 | c->u.a.lensofar = 0; |
3882 | } |
783415f8 |
3883 | } else { |
3884 | error = "Unsupported channel type requested"; |
3885 | } |
3886 | |
3887 | c->remoteid = ssh2_pkt_getuint32(); |
3888 | if (error) { |
3889 | ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE); |
3890 | ssh2_pkt_adduint32(c->remoteid); |
3891 | ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED); |
3892 | ssh2_pkt_addstring(error); |
3893 | ssh2_pkt_addstring("en"); /* language tag */ |
3894 | ssh2_pkt_send(); |
3895 | sfree(c); |
3896 | } else { |
d2371c81 |
3897 | c->localid = alloc_channel_id(); |
783415f8 |
3898 | c->closes = 0; |
3899 | c->v2.remwindow = ssh2_pkt_getuint32(); |
3900 | c->v2.remmaxpkt = ssh2_pkt_getuint32(); |
3901 | c->v2.outbuffer = NULL; |
3902 | c->v2.outbuflen = c->v2.outbufsize = 0; |
3903 | add234(ssh_channels, c); |
3904 | ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); |
3905 | ssh2_pkt_adduint32(c->remoteid); |
3906 | ssh2_pkt_adduint32(c->localid); |
3907 | ssh2_pkt_adduint32(0x8000UL); /* our window size */ |
3908 | ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */ |
3909 | ssh2_pkt_send(); |
3910 | } |
7cca0d81 |
3911 | } else { |
8d5de777 |
3912 | bombout(("Strange packet received: type %d", pktin.type)); |
3913 | crReturnV; |
7cca0d81 |
3914 | } |
3915 | } else { |
d211621f |
3916 | /* |
3917 | * We have spare data. Add it to the channel buffer. |
3918 | */ |
783415f8 |
3919 | ssh2_add_channel_data(mainchan, in, inlen); |
d211621f |
3920 | try_send = TRUE; |
7cca0d81 |
3921 | } |
d211621f |
3922 | if (try_send) { |
d2371c81 |
3923 | int i; |
783415f8 |
3924 | struct ssh_channel *c; |
d211621f |
3925 | /* |
783415f8 |
3926 | * Try to send data on all channels if we can. |
d211621f |
3927 | */ |
d2371c81 |
3928 | for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) |
783415f8 |
3929 | ssh2_try_send(c); |
d211621f |
3930 | } |
e5574168 |
3931 | } |
3932 | |
3933 | crFinishV; |
3934 | } |
3935 | |
3936 | /* |
7cca0d81 |
3937 | * Handle the top-level SSH2 protocol. |
3938 | */ |
3939 | static void ssh2_protocol(unsigned char *in, int inlen, int ispkt) |
3940 | { |
3941 | if (do_ssh2_transport(in, inlen, ispkt) == 0) |
3942 | return; |
3943 | do_ssh2_authconn(in, inlen, ispkt); |
3944 | } |
3945 | |
3946 | /* |
8df7a775 |
3947 | * Called to set up the connection. |
374330e2 |
3948 | * |
3949 | * Returns an error message, or NULL on success. |
374330e2 |
3950 | */ |
8df7a775 |
3951 | static char *ssh_init (char *host, int port, char **realhost) { |
fb09bf1c |
3952 | char *p; |
8f203108 |
3953 | |
3954 | #ifdef MSCRYPTOAPI |
3955 | if(crypto_startup() == 0) |
3956 | return "Microsoft high encryption pack not installed!"; |
3957 | #endif |
374330e2 |
3958 | |
8df7a775 |
3959 | ssh_send_ok = 0; |
0965bee0 |
3960 | ssh_editing = 0; |
3961 | ssh_echoing = 0; |
8df7a775 |
3962 | |
fb09bf1c |
3963 | p = connect_to_host(host, port, realhost); |
3964 | if (p != NULL) |
3965 | return p; |
374330e2 |
3966 | |
374330e2 |
3967 | return NULL; |
3968 | } |
3969 | |
3970 | /* |
374330e2 |
3971 | * Called to send data down the Telnet connection. |
3972 | */ |
3973 | static void ssh_send (char *buf, int len) { |
f78051a1 |
3974 | if (s == NULL || ssh_protocol == NULL) |
374330e2 |
3975 | return; |
3976 | |
3977 | ssh_protocol(buf, len, 0); |
3978 | } |
3979 | |
3980 | /* |
6e48c3fe |
3981 | * Called to set the size of the window from SSH's POV. |
374330e2 |
3982 | */ |
3983 | static void ssh_size(void) { |
3984 | switch (ssh_state) { |
3985 | case SSH_STATE_BEFORE_SIZE: |
3687d221 |
3986 | case SSH_STATE_PREPACKET: |
21248260 |
3987 | case SSH_STATE_CLOSED: |
374330e2 |
3988 | break; /* do nothing */ |
3989 | case SSH_STATE_INTERMED: |
3990 | size_needed = TRUE; /* buffer for later */ |
3991 | break; |
3992 | case SSH_STATE_SESSION: |
fef97f43 |
3993 | if (!cfg.nopty) { |
6e48c3fe |
3994 | if (ssh_version == 1) { |
3995 | send_packet(SSH1_CMSG_WINDOW_SIZE, |
3996 | PKT_INT, rows, PKT_INT, cols, |
3997 | PKT_INT, 0, PKT_INT, 0, PKT_END); |
3998 | } else { |
3999 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
4000 | ssh2_pkt_adduint32(mainchan->remoteid); |
4001 | ssh2_pkt_addstring("window-change"); |
4002 | ssh2_pkt_addbool(0); |
4003 | ssh2_pkt_adduint32(cols); |
4004 | ssh2_pkt_adduint32(rows); |
4005 | ssh2_pkt_adduint32(0); |
4006 | ssh2_pkt_adduint32(0); |
4007 | ssh2_pkt_send(); |
4008 | } |
fef97f43 |
4009 | } |
3687d221 |
4010 | break; |
374330e2 |
4011 | } |
4012 | } |
4013 | |
4014 | /* |
6abbf9e3 |
4015 | * Send Telnet special codes. TS_EOF is useful for `plink', so you |
4016 | * can send an EOF and collect resulting output (e.g. `plink |
4017 | * hostname sort'). |
374330e2 |
4018 | */ |
4019 | static void ssh_special (Telnet_Special code) { |
6abbf9e3 |
4020 | if (code == TS_EOF) { |
3687d221 |
4021 | if (ssh_state != SSH_STATE_SESSION) { |
4022 | /* |
4023 | * Buffer the EOF in case we are pre-SESSION, so we can |
4024 | * send it as soon as we reach SESSION. |
4025 | */ |
4026 | if (code == TS_EOF) |
4027 | eof_needed = TRUE; |
4028 | return; |
4029 | } |
67779be7 |
4030 | if (ssh_version == 1) { |
6abbf9e3 |
4031 | send_packet(SSH1_CMSG_EOF, PKT_END); |
4032 | } else { |
4033 | ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF); |
d211621f |
4034 | ssh2_pkt_adduint32(mainchan->remoteid); |
6abbf9e3 |
4035 | ssh2_pkt_send(); |
4036 | } |
67779be7 |
4037 | logevent("Sent EOF message"); |
ec55b220 |
4038 | } else if (code == TS_PING) { |
3687d221 |
4039 | if (ssh_state == SSH_STATE_CLOSED || ssh_state == SSH_STATE_PREPACKET) |
4040 | return; |
ec55b220 |
4041 | if (ssh_version == 1) { |
4042 | send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END); |
4043 | } else { |
4044 | ssh2_pkt_init(SSH2_MSG_IGNORE); |
4045 | ssh2_pkt_addstring_start(); |
4046 | ssh2_pkt_send(); |
4047 | } |
6abbf9e3 |
4048 | } else { |
4049 | /* do nothing */ |
4050 | } |
374330e2 |
4051 | } |
4052 | |
8df7a775 |
4053 | static Socket ssh_socket(void) { return s; } |
8ccc75b0 |
4054 | |
4055 | static int ssh_sendok(void) { return ssh_send_ok; } |
fb09bf1c |
4056 | |
0965bee0 |
4057 | static int ssh_ldisc(int option) { |
4058 | if (option == LD_ECHO) return ssh_echoing; |
4059 | if (option == LD_EDIT) return ssh_editing; |
4060 | return FALSE; |
4061 | } |
4062 | |
374330e2 |
4063 | Backend ssh_backend = { |
4064 | ssh_init, |
374330e2 |
4065 | ssh_send, |
4066 | ssh_size, |
4017be6d |
4067 | ssh_special, |
8ccc75b0 |
4068 | ssh_socket, |
97db3be4 |
4069 | ssh_sendok, |
0965bee0 |
4070 | ssh_ldisc, |
97db3be4 |
4071 | 22 |
374330e2 |
4072 | }; |