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1 | #include <windows.h> |
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2 | #include <stdio.h> |
3 | #include <stdlib.h> |
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4 | #include <stdarg.h> |
5 | #include <assert.h> |
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6 | |
7 | #include "putty.h" |
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8 | #include "tree234.h" |
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9 | #include "ssh.h" |
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10 | |
11 | #ifndef FALSE |
12 | #define FALSE 0 |
13 | #endif |
14 | #ifndef TRUE |
15 | #define TRUE 1 |
16 | #endif |
17 | |
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18 | #define logevent(s) { logevent(s); \ |
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19 | if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \ |
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20 | fprintf(stderr, "%s\n", s); } |
21 | |
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22 | #define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, sk_close(s), \ |
23 | s = NULL, connection_fatal msg ) |
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24 | |
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25 | #define SSH1_MSG_DISCONNECT 1 /* 0x1 */ |
26 | #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */ |
27 | #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */ |
28 | #define SSH1_CMSG_USER 4 /* 0x4 */ |
29 | #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */ |
30 | #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */ |
31 | #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */ |
32 | #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */ |
33 | #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */ |
34 | #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */ |
35 | #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */ |
36 | #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */ |
37 | #define SSH1_SMSG_SUCCESS 14 /* 0xe */ |
38 | #define SSH1_SMSG_FAILURE 15 /* 0xf */ |
39 | #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */ |
40 | #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */ |
41 | #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */ |
42 | #define SSH1_CMSG_EOF 19 /* 0x13 */ |
43 | #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */ |
44 | #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */ |
45 | #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */ |
46 | #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */ |
47 | #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */ |
48 | #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */ |
49 | #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */ |
50 | #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */ |
51 | #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */ |
52 | #define SSH1_MSG_IGNORE 32 /* 0x20 */ |
53 | #define SSH1_MSG_DEBUG 36 /* 0x24 */ |
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54 | #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */ |
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55 | #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */ |
56 | #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */ |
57 | #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */ |
58 | #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */ |
59 | #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */ |
60 | #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */ |
61 | |
62 | #define SSH1_AUTH_TIS 5 /* 0x5 */ |
63 | #define SSH1_AUTH_CCARD 16 /* 0x10 */ |
64 | |
65 | #define SSH_AGENTC_REQUEST_RSA_IDENTITIES 1 /* 0x1 */ |
66 | #define SSH_AGENT_RSA_IDENTITIES_ANSWER 2 /* 0x2 */ |
67 | #define SSH_AGENTC_RSA_CHALLENGE 3 /* 0x3 */ |
68 | #define SSH_AGENT_RSA_RESPONSE 4 /* 0x4 */ |
69 | #define SSH_AGENT_FAILURE 5 /* 0x5 */ |
70 | #define SSH_AGENT_SUCCESS 6 /* 0x6 */ |
71 | #define SSH_AGENTC_ADD_RSA_IDENTITY 7 /* 0x7 */ |
72 | #define SSH_AGENTC_REMOVE_RSA_IDENTITY 8 /* 0x8 */ |
73 | |
74 | #define SSH2_MSG_DISCONNECT 1 /* 0x1 */ |
75 | #define SSH2_MSG_IGNORE 2 /* 0x2 */ |
76 | #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */ |
77 | #define SSH2_MSG_DEBUG 4 /* 0x4 */ |
78 | #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */ |
79 | #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */ |
80 | #define SSH2_MSG_KEXINIT 20 /* 0x14 */ |
81 | #define SSH2_MSG_NEWKEYS 21 /* 0x15 */ |
82 | #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */ |
83 | #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */ |
84 | #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */ |
85 | #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */ |
86 | #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */ |
87 | #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */ |
88 | #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */ |
89 | #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */ |
90 | #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */ |
91 | #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */ |
92 | #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */ |
93 | #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */ |
94 | #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */ |
95 | #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */ |
96 | #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */ |
97 | #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */ |
98 | #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */ |
99 | #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */ |
100 | #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */ |
101 | #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */ |
102 | #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */ |
103 | #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */ |
104 | |
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105 | #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */ |
106 | #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */ |
107 | #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */ |
108 | #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */ |
109 | #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */ |
110 | #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */ |
111 | #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */ |
112 | #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */ |
113 | #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */ |
114 | #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */ |
115 | #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */ |
116 | |
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117 | #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */ |
118 | #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */ |
119 | #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */ |
120 | #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */ |
121 | |
122 | #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */ |
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123 | |
124 | #define GET_32BIT(cp) \ |
125 | (((unsigned long)(unsigned char)(cp)[0] << 24) | \ |
126 | ((unsigned long)(unsigned char)(cp)[1] << 16) | \ |
127 | ((unsigned long)(unsigned char)(cp)[2] << 8) | \ |
128 | ((unsigned long)(unsigned char)(cp)[3])) |
129 | |
130 | #define PUT_32BIT(cp, value) { \ |
131 | (cp)[0] = (unsigned char)((value) >> 24); \ |
132 | (cp)[1] = (unsigned char)((value) >> 16); \ |
133 | (cp)[2] = (unsigned char)((value) >> 8); \ |
134 | (cp)[3] = (unsigned char)(value); } |
135 | |
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136 | enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM }; |
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137 | |
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138 | /* Coroutine mechanics for the sillier bits of the code */ |
139 | #define crBegin1 static int crLine = 0; |
140 | #define crBegin2 switch(crLine) { case 0:; |
141 | #define crBegin crBegin1; crBegin2; |
142 | #define crFinish(z) } crLine = 0; return (z) |
143 | #define crFinishV } crLine = 0; return |
144 | #define crReturn(z) \ |
145 | do {\ |
146 | crLine=__LINE__; return (z); case __LINE__:;\ |
147 | } while (0) |
148 | #define crReturnV \ |
149 | do {\ |
150 | crLine=__LINE__; return; case __LINE__:;\ |
151 | } while (0) |
152 | #define crStop(z) do{ crLine = 0; return (z); }while(0) |
153 | #define crStopV do{ crLine = 0; return; }while(0) |
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154 | #define crWaitUntil(c) do { crReturn(0); } while (!(c)) |
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155 | #define crWaitUntilV(c) do { crReturnV; } while (!(c)) |
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156 | |
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157 | extern const struct ssh_cipher ssh_3des; |
158 | extern const struct ssh_cipher ssh_3des_ssh2; |
159 | extern const struct ssh_cipher ssh_des; |
160 | extern const struct ssh_cipher ssh_blowfish_ssh1; |
161 | extern const struct ssh_cipher ssh_blowfish_ssh2; |
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162 | |
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163 | /* |
164 | * Ciphers for SSH2. We miss out single-DES because it isn't |
165 | * supported; also 3DES and Blowfish are both done differently from |
166 | * SSH1. (3DES uses outer chaining; Blowfish has the opposite |
167 | * endianness and different-sized keys.) |
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168 | */ |
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169 | const static struct ssh_cipher *ciphers[] = { &ssh_blowfish_ssh2, &ssh_3des_ssh2 }; |
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170 | |
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171 | extern const struct ssh_kex ssh_diffiehellman; |
172 | const static struct ssh_kex *kex_algs[] = { &ssh_diffiehellman }; |
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173 | |
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174 | extern const struct ssh_signkey ssh_dss; |
175 | const static struct ssh_signkey *hostkey_algs[] = { &ssh_dss }; |
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176 | |
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177 | extern const struct ssh_mac ssh_md5, ssh_sha1, ssh_sha1_buggy; |
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178 | |
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179 | static void nullmac_key(unsigned char *key) { } |
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180 | static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { } |
181 | static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; } |
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182 | const static struct ssh_mac ssh_mac_none = { |
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183 | nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0 |
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184 | }; |
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185 | const static struct ssh_mac *macs[] = { |
186 | &ssh_sha1, &ssh_md5, &ssh_mac_none }; |
187 | const static struct ssh_mac *buggymacs[] = { |
188 | &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none }; |
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189 | |
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190 | static void ssh_comp_none_init(void) { } |
191 | static int ssh_comp_none_block(unsigned char *block, int len, |
192 | unsigned char **outblock, int *outlen) { |
193 | return 0; |
194 | } |
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195 | const static struct ssh_compress ssh_comp_none = { |
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196 | "none", |
197 | ssh_comp_none_init, ssh_comp_none_block, |
198 | ssh_comp_none_init, ssh_comp_none_block |
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199 | }; |
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200 | extern const struct ssh_compress ssh_zlib; |
201 | const static struct ssh_compress *compressions[] = { |
202 | &ssh_zlib, &ssh_comp_none }; |
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203 | |
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204 | /* |
205 | * 2-3-4 tree storing channels. |
206 | */ |
207 | struct ssh_channel { |
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208 | unsigned remoteid, localid; |
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209 | int type; |
210 | int closes; |
211 | union { |
212 | struct ssh_agent_channel { |
213 | unsigned char *message; |
214 | unsigned char msglen[4]; |
215 | int lensofar, totallen; |
216 | } a; |
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217 | struct ssh2_data_channel { |
218 | unsigned char *outbuffer; |
219 | unsigned outbuflen, outbufsize; |
220 | unsigned remwindow, remmaxpkt; |
221 | } v2; |
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222 | } u; |
223 | }; |
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224 | |
225 | struct Packet { |
226 | long length; |
227 | int type; |
228 | unsigned char *data; |
229 | unsigned char *body; |
230 | long savedpos; |
231 | long maxlen; |
232 | }; |
233 | |
234 | static SHA_State exhash; |
235 | |
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236 | static Socket s = NULL; |
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237 | |
238 | static unsigned char session_key[32]; |
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239 | static int ssh1_compressing; |
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240 | static int ssh_agentfwd_enabled; |
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241 | static const struct ssh_cipher *cipher = NULL; |
242 | static const struct ssh_cipher *cscipher = NULL; |
243 | static const struct ssh_cipher *sccipher = NULL; |
244 | static const struct ssh_mac *csmac = NULL; |
245 | static const struct ssh_mac *scmac = NULL; |
246 | static const struct ssh_compress *cscomp = NULL; |
247 | static const struct ssh_compress *sccomp = NULL; |
248 | static const struct ssh_kex *kex = NULL; |
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249 | static const struct ssh_signkey *hostkey = NULL; |
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250 | int (*ssh_get_password)(const char *prompt, char *str, int maxlen) = NULL; |
251 | |
252 | static char *savedhost; |
253 | static int savedport; |
254 | static int ssh_send_ok; |
255 | |
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256 | static tree234 *ssh_channels; /* indexed by local id */ |
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257 | static struct ssh_channel *mainchan; /* primary session channel */ |
258 | |
259 | static enum { |
260 | SSH_STATE_BEFORE_SIZE, |
261 | SSH_STATE_INTERMED, |
262 | SSH_STATE_SESSION, |
263 | SSH_STATE_CLOSED |
264 | } ssh_state = SSH_STATE_BEFORE_SIZE; |
265 | |
266 | static int size_needed = FALSE; |
267 | |
268 | static struct Packet pktin = { 0, 0, NULL, NULL, 0 }; |
269 | static struct Packet pktout = { 0, 0, NULL, NULL, 0 }; |
270 | |
271 | static int ssh_version; |
272 | static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt); |
273 | static void ssh1_protocol(unsigned char *in, int inlen, int ispkt); |
274 | static void ssh2_protocol(unsigned char *in, int inlen, int ispkt); |
275 | static void ssh_size(void); |
276 | |
277 | static int (*s_rdpkt)(unsigned char **data, int *datalen); |
278 | |
279 | static struct rdpkt1_state_tag { |
280 | long len, pad, biglen, to_read; |
281 | unsigned long realcrc, gotcrc; |
282 | unsigned char *p; |
283 | int i; |
284 | int chunk; |
285 | } rdpkt1_state; |
286 | |
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287 | static struct rdpkt2_state_tag { |
288 | long len, pad, payload, packetlen, maclen; |
289 | int i; |
290 | int cipherblk; |
291 | unsigned long incoming_sequence; |
292 | } rdpkt2_state; |
293 | |
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294 | static int ssh_channelcmp(void *av, void *bv) { |
295 | struct ssh_channel *a = (struct ssh_channel *)av; |
296 | struct ssh_channel *b = (struct ssh_channel *)bv; |
297 | if (a->localid < b->localid) return -1; |
298 | if (a->localid > b->localid) return +1; |
299 | return 0; |
300 | } |
301 | static int ssh_channelfind(void *av, void *bv) { |
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302 | unsigned *a = (unsigned *)av; |
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303 | struct ssh_channel *b = (struct ssh_channel *)bv; |
304 | if (*a < b->localid) return -1; |
305 | if (*a > b->localid) return +1; |
306 | return 0; |
307 | } |
308 | |
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309 | static void c_write (char *buf, int len) { |
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310 | if ((flags & FLAG_STDERR)) { |
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311 | int i; |
312 | for (i = 0; i < len; i++) |
313 | if (buf[i] != '\r') |
314 | fputc(buf[i], stderr); |
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315 | return; |
316 | } |
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317 | from_backend(1, buf, len); |
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318 | } |
319 | |
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320 | /* |
321 | * Collect incoming data in the incoming packet buffer. |
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322 | * Decipher and verify the packet when it is completely read. |
323 | * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets. |
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324 | * Update the *data and *datalen variables. |
325 | * Return the additional nr of bytes needed, or 0 when |
326 | * a complete packet is available. |
327 | */ |
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328 | static int ssh1_rdpkt(unsigned char **data, int *datalen) |
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329 | { |
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330 | struct rdpkt1_state_tag *st = &rdpkt1_state; |
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331 | |
332 | crBegin; |
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333 | |
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334 | next_packet: |
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335 | |
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336 | pktin.type = 0; |
337 | pktin.length = 0; |
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338 | |
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339 | for (st->i = st->len = 0; st->i < 4; st->i++) { |
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340 | while ((*datalen) == 0) |
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341 | crReturn(4-st->i); |
342 | st->len = (st->len << 8) + **data; |
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343 | (*data)++, (*datalen)--; |
344 | } |
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345 | |
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346 | #ifdef FWHACK |
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347 | if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */ |
348 | st->len = 0x300; /* big enough to carry to end */ |
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349 | } |
350 | #endif |
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351 | |
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352 | st->pad = 8 - (st->len % 8); |
353 | st->biglen = st->len + st->pad; |
354 | pktin.length = st->len - 5; |
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355 | |
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356 | if (pktin.maxlen < st->biglen) { |
357 | pktin.maxlen = st->biglen; |
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358 | pktin.data = (pktin.data == NULL ? smalloc(st->biglen+APIEXTRA) : |
359 | srealloc(pktin.data, st->biglen+APIEXTRA)); |
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360 | if (!pktin.data) |
361 | fatalbox("Out of memory"); |
362 | } |
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363 | |
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364 | st->to_read = st->biglen; |
365 | st->p = pktin.data; |
366 | while (st->to_read > 0) { |
367 | st->chunk = st->to_read; |
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368 | while ((*datalen) == 0) |
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369 | crReturn(st->to_read); |
370 | if (st->chunk > (*datalen)) |
371 | st->chunk = (*datalen); |
372 | memcpy(st->p, *data, st->chunk); |
373 | *data += st->chunk; |
374 | *datalen -= st->chunk; |
375 | st->p += st->chunk; |
376 | st->to_read -= st->chunk; |
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377 | } |
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378 | |
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379 | if (cipher) |
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380 | cipher->decrypt(pktin.data, st->biglen); |
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381 | #if 0 |
382 | debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad)); |
383 | for (st->i = 0; st->i < st->biglen; st->i++) |
384 | debug((" %02x", (unsigned char)pktin.data[st->i])); |
385 | debug(("\r\n")); |
386 | #endif |
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387 | |
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388 | st->realcrc = crc32(pktin.data, st->biglen-4); |
389 | st->gotcrc = GET_32BIT(pktin.data+st->biglen-4); |
390 | if (st->gotcrc != st->realcrc) { |
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391 | bombout(("Incorrect CRC received on packet")); |
392 | crReturn(0); |
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393 | } |
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394 | |
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395 | pktin.body = pktin.data + st->pad + 1; |
396 | |
397 | if (ssh1_compressing) { |
398 | unsigned char *decompblk; |
399 | int decomplen; |
400 | #if 0 |
401 | int i; |
402 | debug(("Packet payload pre-decompression:\n")); |
403 | for (i = -1; i < pktin.length; i++) |
404 | debug((" %02x", (unsigned char)pktin.body[i])); |
405 | debug(("\r\n")); |
406 | #endif |
407 | zlib_decompress_block(pktin.body-1, pktin.length+1, |
408 | &decompblk, &decomplen); |
409 | |
410 | if (pktin.maxlen < st->pad + decomplen) { |
411 | pktin.maxlen = st->pad + decomplen; |
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412 | pktin.data = srealloc(pktin.data, pktin.maxlen+APIEXTRA); |
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413 | pktin.body = pktin.data + st->pad + 1; |
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414 | if (!pktin.data) |
415 | fatalbox("Out of memory"); |
416 | } |
417 | |
418 | memcpy(pktin.body-1, decompblk, decomplen); |
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419 | sfree(decompblk); |
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420 | pktin.length = decomplen-1; |
421 | #if 0 |
422 | debug(("Packet payload post-decompression:\n")); |
423 | for (i = -1; i < pktin.length; i++) |
424 | debug((" %02x", (unsigned char)pktin.body[i])); |
425 | debug(("\r\n")); |
426 | #endif |
427 | } |
428 | |
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429 | if (pktin.type == SSH1_SMSG_STDOUT_DATA || |
430 | pktin.type == SSH1_SMSG_STDERR_DATA || |
431 | pktin.type == SSH1_MSG_DEBUG || |
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432 | pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE || |
433 | pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) { |
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434 | long strlen = GET_32BIT(pktin.body); |
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435 | if (strlen + 4 != pktin.length) { |
436 | bombout(("Received data packet with bogus string length")); |
437 | crReturn(0); |
438 | } |
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439 | } |
440 | |
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441 | pktin.type = pktin.body[-1]; |
442 | |
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443 | if (pktin.type == SSH1_MSG_DEBUG) { |
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444 | /* log debug message */ |
445 | char buf[80]; |
446 | int strlen = GET_32BIT(pktin.body); |
447 | strcpy(buf, "Remote: "); |
448 | if (strlen > 70) strlen = 70; |
449 | memcpy(buf+8, pktin.body+4, strlen); |
450 | buf[8+strlen] = '\0'; |
451 | logevent(buf); |
452 | goto next_packet; |
e5574168 |
453 | } else if (pktin.type == SSH1_MSG_IGNORE) { |
fb09bf1c |
454 | /* do nothing */ |
455 | goto next_packet; |
456 | } |
457 | |
458 | crFinish(0); |
459 | } |
460 | |
e5574168 |
461 | static int ssh2_rdpkt(unsigned char **data, int *datalen) |
462 | { |
960e736a |
463 | struct rdpkt2_state_tag *st = &rdpkt2_state; |
e5574168 |
464 | |
465 | crBegin; |
466 | |
467 | next_packet: |
e5574168 |
468 | pktin.type = 0; |
469 | pktin.length = 0; |
960e736a |
470 | if (sccipher) |
471 | st->cipherblk = sccipher->blksize; |
e5574168 |
472 | else |
960e736a |
473 | st->cipherblk = 8; |
474 | if (st->cipherblk < 8) |
475 | st->cipherblk = 8; |
476 | |
477 | if (pktin.maxlen < st->cipherblk) { |
478 | pktin.maxlen = st->cipherblk; |
dcbde236 |
479 | pktin.data = (pktin.data == NULL ? smalloc(st->cipherblk+APIEXTRA) : |
480 | srealloc(pktin.data, st->cipherblk+APIEXTRA)); |
e5574168 |
481 | if (!pktin.data) |
482 | fatalbox("Out of memory"); |
483 | } |
484 | |
485 | /* |
486 | * Acquire and decrypt the first block of the packet. This will |
487 | * contain the length and padding details. |
488 | */ |
960e736a |
489 | for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) { |
e5574168 |
490 | while ((*datalen) == 0) |
960e736a |
491 | crReturn(st->cipherblk-st->i); |
492 | pktin.data[st->i] = *(*data)++; |
e5574168 |
493 | (*datalen)--; |
494 | } |
495 | #ifdef FWHACK |
496 | if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */ |
497 | /* FIXME */ |
498 | } |
499 | #endif |
500 | if (sccipher) |
960e736a |
501 | sccipher->decrypt(pktin.data, st->cipherblk); |
e5574168 |
502 | |
503 | /* |
504 | * Now get the length and padding figures. |
505 | */ |
960e736a |
506 | st->len = GET_32BIT(pktin.data); |
507 | st->pad = pktin.data[4]; |
e5574168 |
508 | |
509 | /* |
510 | * This enables us to deduce the payload length. |
511 | */ |
960e736a |
512 | st->payload = st->len - st->pad - 1; |
e5574168 |
513 | |
960e736a |
514 | pktin.length = st->payload + 5; |
e5574168 |
515 | |
516 | /* |
517 | * So now we can work out the total packet length. |
518 | */ |
960e736a |
519 | st->packetlen = st->len + 4; |
520 | st->maclen = scmac ? scmac->len : 0; |
e5574168 |
521 | |
522 | /* |
523 | * Adjust memory allocation if packet is too big. |
524 | */ |
960e736a |
525 | if (pktin.maxlen < st->packetlen+st->maclen) { |
526 | pktin.maxlen = st->packetlen+st->maclen; |
dcbde236 |
527 | pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) : |
528 | srealloc(pktin.data, pktin.maxlen+APIEXTRA)); |
e5574168 |
529 | if (!pktin.data) |
530 | fatalbox("Out of memory"); |
531 | } |
532 | |
533 | /* |
534 | * Read and decrypt the remainder of the packet. |
535 | */ |
960e736a |
536 | for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; st->i++) { |
e5574168 |
537 | while ((*datalen) == 0) |
960e736a |
538 | crReturn(st->packetlen + st->maclen - st->i); |
539 | pktin.data[st->i] = *(*data)++; |
e5574168 |
540 | (*datalen)--; |
541 | } |
542 | /* Decrypt everything _except_ the MAC. */ |
543 | if (sccipher) |
960e736a |
544 | sccipher->decrypt(pktin.data + st->cipherblk, |
545 | st->packetlen - st->cipherblk); |
e5574168 |
546 | |
7cca0d81 |
547 | #if 0 |
960e736a |
548 | debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad)); |
549 | for (st->i = 0; st->i < st->packetlen; st->i++) |
550 | debug((" %02x", (unsigned char)pktin.data[st->i])); |
d39f364a |
551 | debug(("\r\n")); |
7cca0d81 |
552 | #endif |
d39f364a |
553 | |
e5574168 |
554 | /* |
555 | * Check the MAC. |
556 | */ |
960e736a |
557 | if (scmac && !scmac->verify(pktin.data, st->len+4, st->incoming_sequence)) { |
8d5de777 |
558 | bombout(("Incorrect MAC received on packet")); |
559 | crReturn(0); |
560 | } |
960e736a |
561 | st->incoming_sequence++; /* whether or not we MACed */ |
e5574168 |
562 | |
4ba9b64b |
563 | /* |
564 | * Decompress packet payload. |
565 | */ |
566 | { |
567 | unsigned char *newpayload; |
568 | int newlen; |
569 | if (sccomp && sccomp->decompress(pktin.data+5, pktin.length-5, |
570 | &newpayload, &newlen)) { |
571 | if (pktin.maxlen < newlen+5) { |
572 | pktin.maxlen = newlen+5; |
dcbde236 |
573 | pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) : |
574 | srealloc(pktin.data, pktin.maxlen+APIEXTRA)); |
4ba9b64b |
575 | if (!pktin.data) |
576 | fatalbox("Out of memory"); |
577 | } |
578 | pktin.length = 5 + newlen; |
579 | memcpy(pktin.data+5, newpayload, newlen); |
580 | #if 0 |
581 | debug(("Post-decompression payload:\r\n")); |
582 | for (st->i = 0; st->i < newlen; st->i++) |
583 | debug((" %02x", (unsigned char)pktin.data[5+st->i])); |
584 | debug(("\r\n")); |
585 | #endif |
586 | |
dcbde236 |
587 | sfree(newpayload); |
4ba9b64b |
588 | } |
589 | } |
590 | |
e5574168 |
591 | pktin.savedpos = 6; |
592 | pktin.type = pktin.data[5]; |
e5574168 |
593 | |
7cca0d81 |
594 | if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG) |
595 | goto next_packet; /* FIXME: print DEBUG message */ |
e5574168 |
596 | |
597 | crFinish(0); |
598 | } |
599 | |
4ba9b64b |
600 | static void ssh1_pktout_size(int len) { |
374330e2 |
601 | int pad, biglen; |
602 | |
603 | len += 5; /* type and CRC */ |
604 | pad = 8 - (len%8); |
605 | biglen = len + pad; |
606 | |
607 | pktout.length = len-5; |
608 | if (pktout.maxlen < biglen) { |
609 | pktout.maxlen = biglen; |
8f203108 |
610 | #ifdef MSCRYPTOAPI |
fb09bf1c |
611 | /* Allocate enough buffer space for extra block |
8f203108 |
612 | * for MS CryptEncrypt() */ |
dcbde236 |
613 | pktout.data = (pktout.data == NULL ? smalloc(biglen+12) : |
614 | srealloc(pktout.data, biglen+12)); |
8f203108 |
615 | #else |
dcbde236 |
616 | pktout.data = (pktout.data == NULL ? smalloc(biglen+4) : |
617 | srealloc(pktout.data, biglen+4)); |
8f203108 |
618 | #endif |
374330e2 |
619 | if (!pktout.data) |
620 | fatalbox("Out of memory"); |
621 | } |
4ba9b64b |
622 | pktout.body = pktout.data+4+pad+1; |
623 | } |
374330e2 |
624 | |
4ba9b64b |
625 | static void s_wrpkt_start(int type, int len) { |
626 | ssh1_pktout_size(len); |
374330e2 |
627 | pktout.type = type; |
374330e2 |
628 | } |
629 | |
630 | static void s_wrpkt(void) { |
631 | int pad, len, biglen, i; |
632 | unsigned long crc; |
633 | |
4ba9b64b |
634 | pktout.body[-1] = pktout.type; |
635 | |
636 | if (ssh1_compressing) { |
637 | unsigned char *compblk; |
638 | int complen; |
639 | #if 0 |
640 | debug(("Packet payload pre-compression:\n")); |
641 | for (i = -1; i < pktout.length; i++) |
642 | debug((" %02x", (unsigned char)pktout.body[i])); |
643 | debug(("\r\n")); |
644 | #endif |
645 | zlib_compress_block(pktout.body-1, pktout.length+1, |
646 | &compblk, &complen); |
647 | ssh1_pktout_size(complen-1); |
648 | memcpy(pktout.body-1, compblk, complen); |
dcbde236 |
649 | sfree(compblk); |
4ba9b64b |
650 | #if 0 |
651 | debug(("Packet payload post-compression:\n")); |
652 | for (i = -1; i < pktout.length; i++) |
653 | debug((" %02x", (unsigned char)pktout.body[i])); |
654 | debug(("\r\n")); |
655 | #endif |
656 | } |
657 | |
374330e2 |
658 | len = pktout.length + 5; /* type and CRC */ |
659 | pad = 8 - (len%8); |
660 | biglen = len + pad; |
661 | |
374330e2 |
662 | for (i=0; i<pad; i++) |
663 | pktout.data[i+4] = random_byte(); |
664 | crc = crc32(pktout.data+4, biglen-4); |
fb09bf1c |
665 | PUT_32BIT(pktout.data+biglen, crc); |
666 | PUT_32BIT(pktout.data, len); |
374330e2 |
667 | |
698a5108 |
668 | #if 0 |
669 | debug(("Sending packet len=%d\r\n", biglen+4)); |
670 | for (i = 0; i < biglen+4; i++) |
671 | debug((" %02x", (unsigned char)pktout.data[i])); |
672 | debug(("\r\n")); |
673 | #endif |
374330e2 |
674 | if (cipher) |
675 | cipher->encrypt(pktout.data+4, biglen); |
676 | |
8df7a775 |
677 | sk_write(s, pktout.data, biglen+4); |
374330e2 |
678 | } |
679 | |
fb09bf1c |
680 | /* |
681 | * Construct a packet with the specified contents and |
682 | * send it to the server. |
683 | */ |
684 | static void send_packet(int pkttype, ...) |
685 | { |
686 | va_list args; |
687 | unsigned char *p, *argp, argchar; |
688 | unsigned long argint; |
689 | int pktlen, argtype, arglen; |
7cca0d81 |
690 | Bignum bn; |
fb09bf1c |
691 | |
692 | pktlen = 0; |
693 | va_start(args, pkttype); |
694 | while ((argtype = va_arg(args, int)) != PKT_END) { |
695 | switch (argtype) { |
696 | case PKT_INT: |
697 | (void) va_arg(args, int); |
698 | pktlen += 4; |
699 | break; |
700 | case PKT_CHAR: |
701 | (void) va_arg(args, char); |
702 | pktlen++; |
703 | break; |
704 | case PKT_DATA: |
705 | (void) va_arg(args, unsigned char *); |
706 | arglen = va_arg(args, int); |
707 | pktlen += arglen; |
708 | break; |
709 | case PKT_STR: |
710 | argp = va_arg(args, unsigned char *); |
711 | arglen = strlen(argp); |
712 | pktlen += 4 + arglen; |
713 | break; |
7cca0d81 |
714 | case PKT_BIGNUM: |
715 | bn = va_arg(args, Bignum); |
5c58ad2d |
716 | pktlen += ssh1_bignum_length(bn); |
7cca0d81 |
717 | break; |
fb09bf1c |
718 | default: |
719 | assert(0); |
720 | } |
721 | } |
722 | va_end(args); |
723 | |
724 | s_wrpkt_start(pkttype, pktlen); |
725 | p = pktout.body; |
726 | |
727 | va_start(args, pkttype); |
728 | while ((argtype = va_arg(args, int)) != PKT_END) { |
729 | switch (argtype) { |
730 | case PKT_INT: |
731 | argint = va_arg(args, int); |
732 | PUT_32BIT(p, argint); |
733 | p += 4; |
734 | break; |
735 | case PKT_CHAR: |
736 | argchar = va_arg(args, unsigned char); |
737 | *p = argchar; |
738 | p++; |
739 | break; |
740 | case PKT_DATA: |
741 | argp = va_arg(args, unsigned char *); |
742 | arglen = va_arg(args, int); |
743 | memcpy(p, argp, arglen); |
744 | p += arglen; |
745 | break; |
746 | case PKT_STR: |
747 | argp = va_arg(args, unsigned char *); |
748 | arglen = strlen(argp); |
749 | PUT_32BIT(p, arglen); |
750 | memcpy(p + 4, argp, arglen); |
751 | p += 4 + arglen; |
752 | break; |
7cca0d81 |
753 | case PKT_BIGNUM: |
754 | bn = va_arg(args, Bignum); |
5c58ad2d |
755 | p += ssh1_write_bignum(p, bn); |
7cca0d81 |
756 | break; |
fb09bf1c |
757 | } |
758 | } |
759 | va_end(args); |
760 | |
761 | s_wrpkt(); |
762 | } |
763 | |
9697bfd2 |
764 | static int ssh_versioncmp(char *a, char *b) { |
765 | char *ae, *be; |
766 | unsigned long av, bv; |
767 | |
43aa02a7 |
768 | av = strtoul(a, &ae, 10); |
769 | bv = strtoul(b, &be, 10); |
9697bfd2 |
770 | if (av != bv) return (av < bv ? -1 : +1); |
771 | if (*ae == '.') ae++; |
772 | if (*be == '.') be++; |
43aa02a7 |
773 | av = strtoul(ae, &ae, 10); |
774 | bv = strtoul(be, &be, 10); |
9697bfd2 |
775 | if (av != bv) return (av < bv ? -1 : +1); |
776 | return 0; |
777 | } |
778 | |
e5574168 |
779 | |
780 | /* |
781 | * Utility routine for putting an SSH-protocol `string' into a SHA |
782 | * state. |
783 | */ |
784 | #include <stdio.h> |
75cab814 |
785 | static void sha_string(SHA_State *s, void *str, int len) { |
e5574168 |
786 | unsigned char lenblk[4]; |
e5574168 |
787 | PUT_32BIT(lenblk, len); |
e5574168 |
788 | SHA_Bytes(s, lenblk, 4); |
e5574168 |
789 | SHA_Bytes(s, str, len); |
790 | } |
791 | |
7cca0d81 |
792 | /* |
793 | * SSH2 packet construction functions. |
794 | */ |
75cab814 |
795 | static void ssh2_pkt_adddata(void *data, int len) { |
7cca0d81 |
796 | pktout.length += len; |
797 | if (pktout.maxlen < pktout.length) { |
798 | pktout.maxlen = pktout.length + 256; |
dcbde236 |
799 | pktout.data = (pktout.data == NULL ? smalloc(pktout.maxlen+APIEXTRA) : |
800 | srealloc(pktout.data, pktout.maxlen+APIEXTRA)); |
7cca0d81 |
801 | if (!pktout.data) |
802 | fatalbox("Out of memory"); |
803 | } |
804 | memcpy(pktout.data+pktout.length-len, data, len); |
805 | } |
75cab814 |
806 | static void ssh2_pkt_addbyte(unsigned char byte) { |
7cca0d81 |
807 | ssh2_pkt_adddata(&byte, 1); |
808 | } |
75cab814 |
809 | static void ssh2_pkt_init(int pkt_type) { |
7cca0d81 |
810 | pktout.length = 5; |
811 | ssh2_pkt_addbyte((unsigned char)pkt_type); |
812 | } |
75cab814 |
813 | static void ssh2_pkt_addbool(unsigned char value) { |
7cca0d81 |
814 | ssh2_pkt_adddata(&value, 1); |
815 | } |
75cab814 |
816 | static void ssh2_pkt_adduint32(unsigned long value) { |
7cca0d81 |
817 | unsigned char x[4]; |
818 | PUT_32BIT(x, value); |
819 | ssh2_pkt_adddata(x, 4); |
820 | } |
75cab814 |
821 | static void ssh2_pkt_addstring_start(void) { |
7cca0d81 |
822 | ssh2_pkt_adduint32(0); |
823 | pktout.savedpos = pktout.length; |
824 | } |
75cab814 |
825 | static void ssh2_pkt_addstring_str(char *data) { |
7cca0d81 |
826 | ssh2_pkt_adddata(data, strlen(data)); |
827 | PUT_32BIT(pktout.data + pktout.savedpos - 4, |
828 | pktout.length - pktout.savedpos); |
829 | } |
75cab814 |
830 | static void ssh2_pkt_addstring_data(char *data, int len) { |
7cca0d81 |
831 | ssh2_pkt_adddata(data, len); |
832 | PUT_32BIT(pktout.data + pktout.savedpos - 4, |
833 | pktout.length - pktout.savedpos); |
834 | } |
75cab814 |
835 | static void ssh2_pkt_addstring(char *data) { |
7cca0d81 |
836 | ssh2_pkt_addstring_start(); |
837 | ssh2_pkt_addstring_str(data); |
838 | } |
75cab814 |
839 | static char *ssh2_mpint_fmt(Bignum b, int *len) { |
7cca0d81 |
840 | unsigned char *p; |
841 | int i, n = b[0]; |
dcbde236 |
842 | p = smalloc(n * 2 + 1); |
7cca0d81 |
843 | if (!p) |
844 | fatalbox("out of memory"); |
845 | p[0] = 0; |
846 | for (i = 0; i < n; i++) { |
847 | p[i*2+1] = (b[n-i] >> 8) & 0xFF; |
848 | p[i*2+2] = (b[n-i] ) & 0xFF; |
849 | } |
850 | i = 0; |
851 | while (p[i] == 0 && (p[i+1] & 0x80) == 0) |
852 | i++; |
853 | memmove(p, p+i, n*2+1-i); |
854 | *len = n*2+1-i; |
855 | return p; |
856 | } |
75cab814 |
857 | static void ssh2_pkt_addmp(Bignum b) { |
7cca0d81 |
858 | unsigned char *p; |
859 | int len; |
860 | p = ssh2_mpint_fmt(b, &len); |
861 | ssh2_pkt_addstring_start(); |
862 | ssh2_pkt_addstring_data(p, len); |
dcbde236 |
863 | sfree(p); |
7cca0d81 |
864 | } |
75cab814 |
865 | static void ssh2_pkt_send(void) { |
7cca0d81 |
866 | int cipherblk, maclen, padding, i; |
867 | static unsigned long outgoing_sequence = 0; |
868 | |
869 | /* |
4ba9b64b |
870 | * Compress packet payload. |
871 | */ |
872 | #if 0 |
873 | debug(("Pre-compression payload:\r\n")); |
874 | for (i = 5; i < pktout.length; i++) |
875 | debug((" %02x", (unsigned char)pktout.data[i])); |
876 | debug(("\r\n")); |
877 | #endif |
878 | { |
879 | unsigned char *newpayload; |
880 | int newlen; |
881 | if (cscomp && cscomp->compress(pktout.data+5, pktout.length-5, |
882 | &newpayload, &newlen)) { |
883 | pktout.length = 5; |
884 | ssh2_pkt_adddata(newpayload, newlen); |
dcbde236 |
885 | sfree(newpayload); |
4ba9b64b |
886 | } |
887 | } |
888 | |
889 | /* |
7cca0d81 |
890 | * Add padding. At least four bytes, and must also bring total |
891 | * length (minus MAC) up to a multiple of the block size. |
892 | */ |
893 | cipherblk = cipher ? cipher->blksize : 8; /* block size */ |
894 | cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */ |
895 | padding = 4; |
896 | padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk; |
897 | pktout.data[4] = padding; |
898 | for (i = 0; i < padding; i++) |
899 | pktout.data[pktout.length + i] = random_byte(); |
900 | PUT_32BIT(pktout.data, pktout.length + padding - 4); |
901 | if (csmac) |
902 | csmac->generate(pktout.data, pktout.length + padding, |
903 | outgoing_sequence); |
904 | outgoing_sequence++; /* whether or not we MACed */ |
905 | |
906 | #if 0 |
907 | debug(("Sending packet len=%d\r\n", pktout.length+padding)); |
908 | for (i = 0; i < pktout.length+padding; i++) |
909 | debug((" %02x", (unsigned char)pktout.data[i])); |
910 | debug(("\r\n")); |
911 | #endif |
912 | |
913 | if (cscipher) |
914 | cscipher->encrypt(pktout.data, pktout.length + padding); |
915 | maclen = csmac ? csmac->len : 0; |
916 | |
8df7a775 |
917 | sk_write(s, pktout.data, pktout.length + padding + maclen); |
7cca0d81 |
918 | } |
919 | |
920 | #if 0 |
921 | void bndebug(char *string, Bignum b) { |
922 | unsigned char *p; |
923 | int i, len; |
924 | p = ssh2_mpint_fmt(b, &len); |
925 | debug(("%s", string)); |
926 | for (i = 0; i < len; i++) |
927 | debug((" %02x", p[i])); |
928 | debug(("\r\n")); |
dcbde236 |
929 | sfree(p); |
7cca0d81 |
930 | } |
931 | #endif |
932 | |
75cab814 |
933 | static void sha_mpint(SHA_State *s, Bignum b) { |
7cca0d81 |
934 | unsigned char *p; |
935 | int len; |
936 | p = ssh2_mpint_fmt(b, &len); |
937 | sha_string(s, p, len); |
dcbde236 |
938 | sfree(p); |
7cca0d81 |
939 | } |
940 | |
941 | /* |
942 | * SSH2 packet decode functions. |
943 | */ |
75cab814 |
944 | static unsigned long ssh2_pkt_getuint32(void) { |
7cca0d81 |
945 | unsigned long value; |
946 | if (pktin.length - pktin.savedpos < 4) |
947 | return 0; /* arrgh, no way to decline (FIXME?) */ |
948 | value = GET_32BIT(pktin.data+pktin.savedpos); |
949 | pktin.savedpos += 4; |
950 | return value; |
951 | } |
75cab814 |
952 | static void ssh2_pkt_getstring(char **p, int *length) { |
7cca0d81 |
953 | *p = NULL; |
954 | if (pktin.length - pktin.savedpos < 4) |
955 | return; |
956 | *length = GET_32BIT(pktin.data+pktin.savedpos); |
957 | pktin.savedpos += 4; |
958 | if (pktin.length - pktin.savedpos < *length) |
959 | return; |
960 | *p = pktin.data+pktin.savedpos; |
961 | pktin.savedpos += *length; |
962 | } |
75cab814 |
963 | static Bignum ssh2_pkt_getmp(void) { |
7cca0d81 |
964 | char *p; |
965 | int i, j, length; |
966 | Bignum b; |
967 | |
968 | ssh2_pkt_getstring(&p, &length); |
969 | if (!p) |
970 | return NULL; |
8d5de777 |
971 | if (p[0] & 0x80) { |
972 | bombout(("internal error: Can't handle negative mpints")); |
973 | return NULL; |
974 | } |
7cca0d81 |
975 | b = newbn((length+1)/2); |
976 | for (i = 0; i < length; i++) { |
977 | j = length - 1 - i; |
978 | if (j & 1) |
979 | b[j/2+1] |= ((unsigned char)p[i]) << 8; |
980 | else |
981 | b[j/2+1] |= ((unsigned char)p[i]); |
982 | } |
6b4e00ee |
983 | while (b[0] > 1 && b[b[0]] == 0) b[0]--; |
7cca0d81 |
984 | return b; |
985 | } |
986 | |
8df7a775 |
987 | static int do_ssh_init(unsigned char c) { |
988 | static char *vsp; |
989 | static char version[10]; |
990 | static char vstring[80]; |
991 | static char vlog[sizeof(vstring)+20]; |
992 | static int i; |
374330e2 |
993 | |
8df7a775 |
994 | crBegin; |
995 | |
996 | /* Search for the string "SSH-" in the input. */ |
374330e2 |
997 | i = 0; |
8df7a775 |
998 | while (1) { |
999 | static const int transS[] = { 1, 2, 2, 1 }; |
1000 | static const int transH[] = { 0, 0, 3, 0 }; |
1001 | static const int transminus[] = { 0, 0, 0, -1 }; |
1002 | if (c == 'S') i = transS[i]; |
1003 | else if (c == 'H') i = transH[i]; |
1004 | else if (c == '-') i = transminus[i]; |
374330e2 |
1005 | else i = 0; |
8df7a775 |
1006 | if (i < 0) |
1007 | break; |
1008 | crReturn(1); /* get another character */ |
374330e2 |
1009 | } |
8df7a775 |
1010 | |
c5e9c988 |
1011 | strcpy(vstring, "SSH-"); |
1012 | vsp = vstring+4; |
374330e2 |
1013 | i = 0; |
1014 | while (1) { |
8df7a775 |
1015 | crReturn(1); /* get another char */ |
c5e9c988 |
1016 | if (vsp < vstring+sizeof(vstring)-1) |
1017 | *vsp++ = c; |
374330e2 |
1018 | if (i >= 0) { |
1019 | if (c == '-') { |
1020 | version[i] = '\0'; |
1021 | i = -1; |
1022 | } else if (i < sizeof(version)-1) |
1023 | version[i++] = c; |
1024 | } |
1025 | else if (c == '\n') |
1026 | break; |
1027 | } |
1028 | |
db7d555c |
1029 | ssh_agentfwd_enabled = FALSE; |
960e736a |
1030 | rdpkt2_state.incoming_sequence = 0; |
1031 | |
c5e9c988 |
1032 | *vsp = 0; |
1033 | sprintf(vlog, "Server version: %s", vstring); |
1034 | vlog[strcspn(vlog, "\r\n")] = '\0'; |
1035 | logevent(vlog); |
1036 | |
adf799dd |
1037 | /* |
1038 | * Server version "1.99" means we can choose whether we use v1 |
1039 | * or v2 protocol. Choice is based on cfg.sshprot. |
1040 | */ |
1041 | if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) { |
e5574168 |
1042 | /* |
1043 | * This is a v2 server. Begin v2 protocol. |
1044 | */ |
1045 | char *verstring = "SSH-2.0-PuTTY"; |
1046 | SHA_Init(&exhash); |
1047 | /* |
1048 | * Hash our version string and their version string. |
1049 | */ |
1050 | sha_string(&exhash, verstring, strlen(verstring)); |
1051 | sha_string(&exhash, vstring, strcspn(vstring, "\r\n")); |
1052 | sprintf(vstring, "%s\n", verstring); |
1053 | sprintf(vlog, "We claim version: %s", verstring); |
1054 | logevent(vlog); |
1055 | logevent("Using SSH protocol version 2"); |
8df7a775 |
1056 | sk_write(s, vstring, strlen(vstring)); |
e5574168 |
1057 | ssh_protocol = ssh2_protocol; |
6abbf9e3 |
1058 | ssh_version = 2; |
e5574168 |
1059 | s_rdpkt = ssh2_rdpkt; |
1060 | } else { |
1061 | /* |
1062 | * This is a v1 server. Begin v1 protocol. |
1063 | */ |
1064 | sprintf(vstring, "SSH-%s-PuTTY\n", |
1065 | (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5")); |
1066 | sprintf(vlog, "We claim version: %s", vstring); |
1067 | vlog[strcspn(vlog, "\r\n")] = '\0'; |
1068 | logevent(vlog); |
1069 | logevent("Using SSH protocol version 1"); |
8df7a775 |
1070 | sk_write(s, vstring, strlen(vstring)); |
e5574168 |
1071 | ssh_protocol = ssh1_protocol; |
6abbf9e3 |
1072 | ssh_version = 1; |
e5574168 |
1073 | s_rdpkt = ssh1_rdpkt; |
1074 | } |
8df7a775 |
1075 | |
1076 | crFinish(0); |
1077 | } |
1078 | |
1079 | static void ssh_gotdata(unsigned char *data, int datalen) |
1080 | { |
1081 | crBegin; |
1082 | |
1083 | /* |
1084 | * To begin with, feed the characters one by one to the |
1085 | * protocol initialisation / selection function do_ssh_init(). |
1086 | * When that returns 0, we're done with the initial greeting |
1087 | * exchange and can move on to packet discipline. |
1088 | */ |
1089 | while (1) { |
1090 | int ret; |
1091 | if (datalen == 0) |
1092 | crReturnV; /* more data please */ |
1093 | ret = do_ssh_init(*data); |
1094 | data++; datalen--; |
1095 | if (ret == 0) |
1096 | break; |
1097 | } |
1098 | |
1099 | /* |
1100 | * We emerge from that loop when the initial negotiation is |
1101 | * over and we have selected an s_rdpkt function. Now pass |
1102 | * everything to s_rdpkt, and then pass the resulting packets |
1103 | * to the proper protocol handler. |
1104 | */ |
1105 | if (datalen == 0) |
1106 | crReturnV; |
1107 | while (1) { |
1108 | while (datalen > 0) { |
1109 | if ( s_rdpkt(&data, &datalen) == 0 ) { |
1110 | ssh_protocol(NULL, 0, 1); |
1111 | if (ssh_state == SSH_STATE_CLOSED) { |
1112 | return; |
1113 | } |
1114 | } |
1115 | } |
1116 | crReturnV; |
1117 | } |
1118 | crFinishV; |
1119 | } |
1120 | |
340cf649 |
1121 | static int ssh_receive(Socket skt, int urgent, char *data, int len) { |
8df7a775 |
1122 | if (!len) { |
1123 | /* Connection has closed. */ |
1124 | sk_close(s); |
1125 | s = NULL; |
1126 | return 0; |
1127 | } |
1128 | ssh_gotdata (data, len); |
3257deae |
1129 | if (ssh_state == SSH_STATE_CLOSED) { |
1130 | if (s) { |
1131 | sk_close(s); |
1132 | s = NULL; |
1133 | } |
1134 | return 0; |
1135 | } |
fef97f43 |
1136 | return 1; |
374330e2 |
1137 | } |
1138 | |
fb09bf1c |
1139 | /* |
8df7a775 |
1140 | * Connect to specified host and port. |
1141 | * Returns an error message, or NULL on success. |
1142 | * Also places the canonical host name into `realhost'. |
1143 | */ |
1144 | static char *connect_to_host(char *host, int port, char **realhost) |
1145 | { |
1146 | SockAddr addr; |
1147 | char *err; |
1148 | #ifdef FWHACK |
1149 | char *FWhost; |
1150 | int FWport; |
1151 | #endif |
1152 | |
dcbde236 |
1153 | savedhost = smalloc(1+strlen(host)); |
8df7a775 |
1154 | if (!savedhost) |
1155 | fatalbox("Out of memory"); |
1156 | strcpy(savedhost, host); |
1157 | |
1158 | if (port < 0) |
1159 | port = 22; /* default ssh port */ |
1160 | savedport = port; |
1161 | |
1162 | #ifdef FWHACK |
1163 | FWhost = host; |
1164 | FWport = port; |
1165 | host = FWSTR; |
1166 | port = 23; |
1167 | #endif |
1168 | |
1169 | /* |
1170 | * Try to find host. |
1171 | */ |
1172 | addr = sk_namelookup(host, realhost); |
1173 | if ( (err = sk_addr_error(addr)) ) |
1174 | return err; |
1175 | |
1176 | #ifdef FWHACK |
1177 | *realhost = FWhost; |
1178 | #endif |
1179 | |
1180 | /* |
1181 | * Open socket. |
1182 | */ |
1183 | s = sk_new(addr, port, ssh_receive); |
1184 | if ( (err = sk_socket_error(s)) ) |
1185 | return err; |
1186 | |
1187 | #ifdef FWHACK |
1188 | sk_write(s, "connect ", 8); |
1189 | sk_write(s, FWhost, strlen(FWhost)); |
1190 | { |
1191 | char buf[20]; |
1192 | sprintf(buf, " %d\n", FWport); |
1193 | sk_write(s, buf, strlen(buf)); |
1194 | } |
1195 | #endif |
1196 | |
1197 | return NULL; |
1198 | } |
1199 | |
1200 | /* |
fb09bf1c |
1201 | * Handle the key exchange and user authentication phases. |
1202 | */ |
e5574168 |
1203 | static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) |
fb09bf1c |
1204 | { |
374330e2 |
1205 | int i, j, len; |
374330e2 |
1206 | unsigned char *rsabuf, *keystr1, *keystr2; |
1207 | unsigned char cookie[8]; |
1208 | struct RSAKey servkey, hostkey; |
1209 | struct MD5Context md5c; |
ccbfb941 |
1210 | static unsigned long supported_ciphers_mask, supported_auths_mask; |
7cca0d81 |
1211 | static int tried_publickey; |
1212 | static unsigned char session_id[16]; |
bea1ef5f |
1213 | int cipher_type; |
b585ec46 |
1214 | static char username[100]; |
374330e2 |
1215 | |
374330e2 |
1216 | crBegin; |
1217 | |
fb09bf1c |
1218 | if (!ispkt) crWaitUntil(ispkt); |
374330e2 |
1219 | |
8d5de777 |
1220 | if (pktin.type != SSH1_SMSG_PUBLIC_KEY) { |
1221 | bombout(("Public key packet not received")); |
1222 | crReturn(0); |
1223 | } |
374330e2 |
1224 | |
c5e9c988 |
1225 | logevent("Received public keys"); |
374330e2 |
1226 | |
c5e9c988 |
1227 | memcpy(cookie, pktin.body, 8); |
374330e2 |
1228 | |
7cca0d81 |
1229 | i = makekey(pktin.body+8, &servkey, &keystr1, 0); |
1230 | j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0); |
374330e2 |
1231 | |
c5e9c988 |
1232 | /* |
1c2a93c4 |
1233 | * Log the host key fingerprint. |
c5e9c988 |
1234 | */ |
c5e9c988 |
1235 | { |
1236 | char logmsg[80]; |
1c2a93c4 |
1237 | logevent("Host key fingerprint is:"); |
c5e9c988 |
1238 | strcpy(logmsg, " "); |
1c2a93c4 |
1239 | hostkey.comment = NULL; |
1240 | rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg), |
1241 | &hostkey); |
c5e9c988 |
1242 | logevent(logmsg); |
1243 | } |
1244 | |
fb09bf1c |
1245 | supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j); |
1246 | supported_auths_mask = GET_32BIT(pktin.body+16+i+j); |
bea1ef5f |
1247 | |
c5e9c988 |
1248 | MD5Init(&md5c); |
374330e2 |
1249 | MD5Update(&md5c, keystr2, hostkey.bytes); |
1250 | MD5Update(&md5c, keystr1, servkey.bytes); |
1251 | MD5Update(&md5c, pktin.body, 8); |
374330e2 |
1252 | MD5Final(session_id, &md5c); |
1253 | |
1254 | for (i=0; i<32; i++) |
1255 | session_key[i] = random_byte(); |
1256 | |
1257 | len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes); |
1258 | |
dcbde236 |
1259 | rsabuf = smalloc(len); |
374330e2 |
1260 | if (!rsabuf) |
1261 | fatalbox("Out of memory"); |
1262 | |
89ee5268 |
1263 | /* |
1264 | * Verify the host key. |
1265 | */ |
1266 | { |
1267 | /* |
1268 | * First format the key into a string. |
1269 | */ |
1270 | int len = rsastr_len(&hostkey); |
d5859615 |
1271 | char fingerprint[100]; |
dcbde236 |
1272 | char *keystr = smalloc(len); |
89ee5268 |
1273 | if (!keystr) |
1274 | fatalbox("Out of memory"); |
1275 | rsastr_fmt(keystr, &hostkey); |
d5859615 |
1276 | rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey); |
d4857987 |
1277 | verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint); |
dcbde236 |
1278 | sfree(keystr); |
89ee5268 |
1279 | } |
374330e2 |
1280 | |
1281 | for (i=0; i<32; i++) { |
1282 | rsabuf[i] = session_key[i]; |
1283 | if (i < 16) |
1284 | rsabuf[i] ^= session_id[i]; |
1285 | } |
1286 | |
1287 | if (hostkey.bytes > servkey.bytes) { |
1288 | rsaencrypt(rsabuf, 32, &servkey); |
1289 | rsaencrypt(rsabuf, servkey.bytes, &hostkey); |
1290 | } else { |
1291 | rsaencrypt(rsabuf, 32, &hostkey); |
1292 | rsaencrypt(rsabuf, hostkey.bytes, &servkey); |
1293 | } |
1294 | |
c5e9c988 |
1295 | logevent("Encrypted session key"); |
1296 | |
bea1ef5f |
1297 | cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH : |
9697bfd2 |
1298 | cfg.cipher == CIPHER_DES ? SSH_CIPHER_DES : |
bea1ef5f |
1299 | SSH_CIPHER_3DES; |
1300 | if ((supported_ciphers_mask & (1 << cipher_type)) == 0) { |
1301 | c_write("Selected cipher not supported, falling back to 3DES\r\n", 53); |
1302 | cipher_type = SSH_CIPHER_3DES; |
1303 | } |
c5e9c988 |
1304 | switch (cipher_type) { |
1305 | case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break; |
1306 | case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break; |
1307 | case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break; |
1308 | } |
bea1ef5f |
1309 | |
e5574168 |
1310 | send_packet(SSH1_CMSG_SESSION_KEY, |
fb09bf1c |
1311 | PKT_CHAR, cipher_type, |
1312 | PKT_DATA, cookie, 8, |
1313 | PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF, |
1314 | PKT_DATA, rsabuf, len, |
1315 | PKT_INT, 0, |
1316 | PKT_END); |
1317 | |
c5e9c988 |
1318 | logevent("Trying to enable encryption..."); |
374330e2 |
1319 | |
dcbde236 |
1320 | sfree(rsabuf); |
374330e2 |
1321 | |
5e8358ad |
1322 | cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 : |
9697bfd2 |
1323 | cipher_type == SSH_CIPHER_DES ? &ssh_des : |
bea1ef5f |
1324 | &ssh_3des; |
374330e2 |
1325 | cipher->sesskey(session_key); |
1326 | |
fb09bf1c |
1327 | crWaitUntil(ispkt); |
374330e2 |
1328 | |
8d5de777 |
1329 | if (pktin.type != SSH1_SMSG_SUCCESS) { |
1330 | bombout(("Encryption not successfully enabled")); |
1331 | crReturn(0); |
1332 | } |
374330e2 |
1333 | |
c5e9c988 |
1334 | logevent("Successfully started encryption"); |
1335 | |
374330e2 |
1336 | fflush(stdout); |
1337 | { |
374330e2 |
1338 | static int pos = 0; |
1339 | static char c; |
67779be7 |
1340 | if ((flags & FLAG_INTERACTIVE) && !*cfg.username) { |
374330e2 |
1341 | c_write("login as: ", 10); |
67779be7 |
1342 | ssh_send_ok = 1; |
374330e2 |
1343 | while (pos >= 0) { |
fb09bf1c |
1344 | crWaitUntil(!ispkt); |
374330e2 |
1345 | while (inlen--) switch (c = *in++) { |
1346 | case 10: case 13: |
1347 | username[pos] = 0; |
1348 | pos = -1; |
1349 | break; |
1350 | case 8: case 127: |
1351 | if (pos > 0) { |
1352 | c_write("\b \b", 3); |
1353 | pos--; |
1354 | } |
1355 | break; |
1356 | case 21: case 27: |
1357 | while (pos > 0) { |
1358 | c_write("\b \b", 3); |
1359 | pos--; |
1360 | } |
1361 | break; |
1362 | case 3: case 4: |
1363 | random_save_seed(); |
1364 | exit(0); |
1365 | break; |
1366 | default: |
40d24aa6 |
1367 | if (((c >= ' ' && c <= '~') || |
1368 | ((unsigned char)c >= 160)) && pos < 40) { |
374330e2 |
1369 | username[pos++] = c; |
1370 | c_write(&c, 1); |
1371 | } |
1372 | break; |
1373 | } |
1374 | } |
1375 | c_write("\r\n", 2); |
1376 | username[strcspn(username, "\n\r")] = '\0'; |
1377 | } else { |
374330e2 |
1378 | strncpy(username, cfg.username, 99); |
1379 | username[99] = '\0'; |
374330e2 |
1380 | } |
fb09bf1c |
1381 | |
e5574168 |
1382 | send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END); |
c5e9c988 |
1383 | { |
3c8e959b |
1384 | char userlog[22+sizeof(username)]; |
c5e9c988 |
1385 | sprintf(userlog, "Sent username \"%s\"", username); |
1386 | logevent(userlog); |
3c8e959b |
1387 | if (flags & FLAG_INTERACTIVE && |
1388 | (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) { |
1389 | strcat(userlog, "\r\n"); |
1390 | c_write(userlog, strlen(userlog)); |
1391 | } |
c5e9c988 |
1392 | } |
374330e2 |
1393 | } |
1394 | |
fb09bf1c |
1395 | crWaitUntil(ispkt); |
374330e2 |
1396 | |
7cca0d81 |
1397 | tried_publickey = 0; |
1398 | |
e5574168 |
1399 | while (pktin.type == SSH1_SMSG_FAILURE) { |
374330e2 |
1400 | static char password[100]; |
a52f067e |
1401 | static char prompt[200]; |
374330e2 |
1402 | static int pos; |
1403 | static char c; |
ccbfb941 |
1404 | static int pwpkt_type; |
ccbfb941 |
1405 | /* |
1406 | * Show password prompt, having first obtained it via a TIS |
18515c51 |
1407 | * or CryptoCard exchange if we're doing TIS or CryptoCard |
1408 | * authentication. |
ccbfb941 |
1409 | */ |
e5574168 |
1410 | pwpkt_type = SSH1_CMSG_AUTH_PASSWORD; |
5c58ad2d |
1411 | if (agent_exists()) { |
1412 | /* |
1413 | * Attempt RSA authentication using Pageant. |
1414 | */ |
1415 | static unsigned char request[5], *response, *p; |
1416 | static int responselen; |
1417 | static int i, nkeys; |
1418 | static int authed = FALSE; |
1419 | void *r; |
1420 | |
1421 | logevent("Pageant is running. Requesting keys."); |
1422 | |
1423 | /* Request the keys held by the agent. */ |
1424 | PUT_32BIT(request, 1); |
1425 | request[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES; |
1426 | agent_query(request, 5, &r, &responselen); |
1427 | response = (unsigned char *)r; |
1428 | if (response) { |
1429 | p = response + 5; |
1430 | nkeys = GET_32BIT(p); p += 4; |
1431 | { char buf[64]; sprintf(buf, "Pageant has %d keys", nkeys); |
1432 | logevent(buf); } |
1433 | for (i = 0; i < nkeys; i++) { |
1434 | static struct RSAKey key; |
1435 | static Bignum challenge; |
b8bb811a |
1436 | static char *commentp; |
1437 | static int commentlen; |
5c58ad2d |
1438 | |
1439 | { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i); |
1440 | logevent(buf); } |
1441 | p += 4; |
1442 | p += ssh1_read_bignum(p, &key.exponent); |
1443 | p += ssh1_read_bignum(p, &key.modulus); |
b8bb811a |
1444 | commentlen = GET_32BIT(p); p += 4; |
1445 | commentp = p; p += commentlen; |
5c58ad2d |
1446 | send_packet(SSH1_CMSG_AUTH_RSA, |
1447 | PKT_BIGNUM, key.modulus, PKT_END); |
1448 | crWaitUntil(ispkt); |
1449 | if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { |
1450 | logevent("Key refused"); |
1451 | continue; |
1452 | } |
1453 | logevent("Received RSA challenge"); |
1454 | ssh1_read_bignum(pktin.body, &challenge); |
1455 | { |
1456 | char *agentreq, *q, *ret; |
1457 | int len, retlen; |
1458 | len = 1 + 4; /* message type, bit count */ |
1459 | len += ssh1_bignum_length(key.exponent); |
1460 | len += ssh1_bignum_length(key.modulus); |
1461 | len += ssh1_bignum_length(challenge); |
1462 | len += 16; /* session id */ |
1463 | len += 4; /* response format */ |
dcbde236 |
1464 | agentreq = smalloc(4 + len); |
5c58ad2d |
1465 | PUT_32BIT(agentreq, len); |
1466 | q = agentreq + 4; |
1467 | *q++ = SSH_AGENTC_RSA_CHALLENGE; |
1468 | PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus)); |
1469 | q += 4; |
1470 | q += ssh1_write_bignum(q, key.exponent); |
1471 | q += ssh1_write_bignum(q, key.modulus); |
1472 | q += ssh1_write_bignum(q, challenge); |
1473 | memcpy(q, session_id, 16); q += 16; |
1474 | PUT_32BIT(q, 1); /* response format */ |
1475 | agent_query(agentreq, len+4, &ret, &retlen); |
dcbde236 |
1476 | sfree(agentreq); |
5c58ad2d |
1477 | if (ret) { |
1478 | if (ret[4] == SSH_AGENT_RSA_RESPONSE) { |
1479 | logevent("Sending Pageant's response"); |
1480 | send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE, |
1481 | PKT_DATA, ret+5, 16, PKT_END); |
dcbde236 |
1482 | sfree(ret); |
5c58ad2d |
1483 | crWaitUntil(ispkt); |
1484 | if (pktin.type == SSH1_SMSG_SUCCESS) { |
1485 | logevent("Pageant's response accepted"); |
c4fa2fce |
1486 | if (flags & FLAG_VERBOSE) { |
1487 | c_write("Authenticated using RSA key \"", |
1488 | 29); |
1489 | c_write(commentp, commentlen); |
1490 | c_write("\" from agent\r\n", 14); |
1491 | } |
5c58ad2d |
1492 | authed = TRUE; |
1493 | } else |
1494 | logevent("Pageant's response not accepted"); |
1495 | } else { |
1496 | logevent("Pageant failed to answer challenge"); |
dcbde236 |
1497 | sfree(ret); |
5c58ad2d |
1498 | } |
1499 | } else { |
1500 | logevent("No reply received from Pageant"); |
1501 | } |
1502 | } |
1503 | freebn(key.exponent); |
1504 | freebn(key.modulus); |
1505 | freebn(challenge); |
1506 | if (authed) |
1507 | break; |
1508 | } |
1509 | } |
1510 | if (authed) |
1511 | break; |
1512 | } |
7cca0d81 |
1513 | if (*cfg.keyfile && !tried_publickey) |
1514 | pwpkt_type = SSH1_CMSG_AUTH_RSA; |
fb09bf1c |
1515 | |
a52f067e |
1516 | if (pktin.type == SSH1_SMSG_FAILURE && |
1517 | cfg.try_tis_auth && |
1518 | (supported_auths_mask & (1<<SSH1_AUTH_TIS))) { |
1519 | pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE; |
1520 | logevent("Requested TIS authentication"); |
1521 | send_packet(SSH1_CMSG_AUTH_TIS, PKT_END); |
1522 | crWaitUntil(ispkt); |
1523 | if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) { |
1524 | logevent("TIS authentication declined"); |
1525 | if (flags & FLAG_INTERACTIVE) |
1526 | c_write("TIS authentication refused.\r\n", 29); |
1527 | } else { |
1528 | int challengelen = ((pktin.body[0] << 24) | |
1529 | (pktin.body[1] << 16) | |
1530 | (pktin.body[2] << 8) | |
1531 | (pktin.body[3])); |
1532 | logevent("Received TIS challenge"); |
1533 | if (challengelen > sizeof(prompt)-1) |
1534 | challengelen = sizeof(prompt)-1; /* prevent overrun */ |
1535 | memcpy(prompt, pktin.body+4, challengelen); |
1536 | prompt[challengelen] = '\0'; |
1537 | } |
1538 | } |
1539 | if (pktin.type == SSH1_SMSG_FAILURE && |
1540 | cfg.try_tis_auth && |
1541 | (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) { |
1542 | pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE; |
1543 | logevent("Requested CryptoCard authentication"); |
1544 | send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END); |
1545 | crWaitUntil(ispkt); |
1546 | if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) { |
1547 | logevent("CryptoCard authentication declined"); |
1548 | c_write("CryptoCard authentication refused.\r\n", 29); |
1549 | } else { |
1550 | int challengelen = ((pktin.body[0] << 24) | |
1551 | (pktin.body[1] << 16) | |
1552 | (pktin.body[2] << 8) | |
1553 | (pktin.body[3])); |
1554 | logevent("Received CryptoCard challenge"); |
1555 | if (challengelen > sizeof(prompt)-1) |
1556 | challengelen = sizeof(prompt)-1; /* prevent overrun */ |
1557 | memcpy(prompt, pktin.body+4, challengelen); |
1558 | strncpy(prompt + challengelen, "\r\nResponse : ", |
1559 | sizeof(prompt)-challengelen); |
1560 | prompt[sizeof(prompt)-1] = '\0'; |
1561 | } |
1562 | } |
1563 | if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) { |
1564 | sprintf(prompt, "%.90s@%.90s's password: ", |
b585ec46 |
1565 | username, savedhost); |
a52f067e |
1566 | } |
1567 | if (pwpkt_type == SSH1_CMSG_AUTH_RSA) { |
1568 | char *comment = NULL; |
1569 | if (flags & FLAG_VERBOSE) |
1570 | c_write("Trying public key authentication.\r\n", 35); |
1571 | if (!rsakey_encrypted(cfg.keyfile, &comment)) { |
1572 | if (flags & FLAG_VERBOSE) |
1573 | c_write("No passphrase required.\r\n", 25); |
1574 | goto tryauth; |
1575 | } |
1576 | sprintf(prompt, "Passphrase for key \"%.100s\": ", comment); |
dcbde236 |
1577 | sfree(comment); |
a52f067e |
1578 | } |
1579 | |
d8426c54 |
1580 | if (ssh_get_password) { |
85ee8208 |
1581 | if (!ssh_get_password(prompt, password, sizeof(password))) { |
1582 | /* |
1583 | * get_password failed to get a password (for |
1584 | * example because one was supplied on the command |
1585 | * line which has already failed to work). |
1586 | * Terminate. |
1587 | */ |
1588 | logevent("No more passwords to try"); |
1589 | ssh_state = SSH_STATE_CLOSED; |
1590 | crReturn(1); |
1591 | } |
fb09bf1c |
1592 | } else { |
a52f067e |
1593 | c_write(prompt, strlen(prompt)); |
7cca0d81 |
1594 | pos = 0; |
67779be7 |
1595 | ssh_send_ok = 1; |
7cca0d81 |
1596 | while (pos >= 0) { |
1597 | crWaitUntil(!ispkt); |
1598 | while (inlen--) switch (c = *in++) { |
1599 | case 10: case 13: |
1600 | password[pos] = 0; |
1601 | pos = -1; |
1602 | break; |
1603 | case 8: case 127: |
1604 | if (pos > 0) |
1605 | pos--; |
1606 | break; |
1607 | case 21: case 27: |
1608 | pos = 0; |
1609 | break; |
1610 | case 3: case 4: |
1611 | random_save_seed(); |
1612 | exit(0); |
1613 | break; |
1614 | default: |
1615 | if (((c >= ' ' && c <= '~') || |
1616 | ((unsigned char)c >= 160)) && pos < sizeof(password)) |
1617 | password[pos++] = c; |
1618 | break; |
1619 | } |
1620 | } |
1621 | c_write("\r\n", 2); |
a52f067e |
1622 | } |
fb09bf1c |
1623 | |
7cca0d81 |
1624 | tryauth: |
1625 | if (pwpkt_type == SSH1_CMSG_AUTH_RSA) { |
1626 | /* |
1627 | * Try public key authentication with the specified |
1628 | * key file. |
1629 | */ |
1630 | static struct RSAKey pubkey; |
1631 | static Bignum challenge, response; |
1632 | static int i; |
1633 | static unsigned char buffer[32]; |
1634 | |
1635 | tried_publickey = 1; |
6e522441 |
1636 | i = loadrsakey(cfg.keyfile, &pubkey, NULL, password); |
7cca0d81 |
1637 | if (i == 0) { |
1638 | c_write("Couldn't load public key from ", 30); |
1639 | c_write(cfg.keyfile, strlen(cfg.keyfile)); |
1640 | c_write(".\r\n", 3); |
1641 | continue; /* go and try password */ |
1642 | } |
1643 | if (i == -1) { |
1644 | c_write("Wrong passphrase.\r\n", 19); |
1645 | tried_publickey = 0; |
1646 | continue; /* try again */ |
1647 | } |
1648 | |
1649 | /* |
1650 | * Send a public key attempt. |
1651 | */ |
1652 | send_packet(SSH1_CMSG_AUTH_RSA, |
1653 | PKT_BIGNUM, pubkey.modulus, PKT_END); |
1654 | |
1655 | crWaitUntil(ispkt); |
1656 | if (pktin.type == SSH1_SMSG_FAILURE) { |
a52f067e |
1657 | c_write("Server refused our public key.\r\n", 32); |
7cca0d81 |
1658 | continue; /* go and try password */ |
1659 | } |
8d5de777 |
1660 | if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { |
1661 | bombout(("Bizarre response to offer of public key")); |
1662 | crReturn(0); |
1663 | } |
7cca0d81 |
1664 | ssh1_read_bignum(pktin.body, &challenge); |
1665 | response = rsadecrypt(challenge, &pubkey); |
1666 | freebn(pubkey.private_exponent); /* burn the evidence */ |
1667 | |
1668 | for (i = 0; i < 32; i += 2) { |
1669 | buffer[i] = response[16-i/2] >> 8; |
1670 | buffer[i+1] = response[16-i/2] & 0xFF; |
1671 | } |
1672 | |
1673 | MD5Init(&md5c); |
1674 | MD5Update(&md5c, buffer, 32); |
1675 | MD5Update(&md5c, session_id, 16); |
1676 | MD5Final(buffer, &md5c); |
1677 | |
1678 | send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE, |
1679 | PKT_DATA, buffer, 16, PKT_END); |
1680 | |
1681 | crWaitUntil(ispkt); |
1682 | if (pktin.type == SSH1_SMSG_FAILURE) { |
4017be6d |
1683 | if (flags & FLAG_VERBOSE) |
1684 | c_write("Failed to authenticate with our public key.\r\n", |
1685 | 45); |
7cca0d81 |
1686 | continue; /* go and try password */ |
1687 | } else if (pktin.type != SSH1_SMSG_SUCCESS) { |
8d5de777 |
1688 | bombout(("Bizarre response to RSA authentication response")); |
1689 | crReturn(0); |
7cca0d81 |
1690 | } |
1691 | |
1692 | break; /* we're through! */ |
1693 | } else { |
1694 | send_packet(pwpkt_type, PKT_STR, password, PKT_END); |
1695 | } |
c5e9c988 |
1696 | logevent("Sent password"); |
374330e2 |
1697 | memset(password, 0, strlen(password)); |
fb09bf1c |
1698 | crWaitUntil(ispkt); |
e5574168 |
1699 | if (pktin.type == SSH1_SMSG_FAILURE) { |
4017be6d |
1700 | if (flags & FLAG_VERBOSE) |
1701 | c_write("Access denied\r\n", 15); |
c5e9c988 |
1702 | logevent("Authentication refused"); |
e5574168 |
1703 | } else if (pktin.type == SSH1_MSG_DISCONNECT) { |
fb09bf1c |
1704 | logevent("Received disconnect request"); |
85ee8208 |
1705 | ssh_state = SSH_STATE_CLOSED; |
1706 | crReturn(1); |
e5574168 |
1707 | } else if (pktin.type != SSH1_SMSG_SUCCESS) { |
8d5de777 |
1708 | bombout(("Strange packet received, type %d", pktin.type)); |
1709 | crReturn(0); |
374330e2 |
1710 | } |
1711 | } |
1712 | |
c5e9c988 |
1713 | logevent("Authentication successful"); |
1714 | |
fb09bf1c |
1715 | crFinish(1); |
1716 | } |
1717 | |
e5574168 |
1718 | static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) { |
fb09bf1c |
1719 | crBegin; |
1720 | |
1721 | random_init(); |
1722 | |
e5574168 |
1723 | while (!do_ssh1_login(in, inlen, ispkt)) { |
fb09bf1c |
1724 | crReturnV; |
85ee8208 |
1725 | } |
1726 | if (ssh_state == SSH_STATE_CLOSED) |
1727 | crReturnV; |
fb09bf1c |
1728 | |
979310f1 |
1729 | if (cfg.agentfwd && agent_exists()) { |
dacbd0e8 |
1730 | logevent("Requesting agent forwarding"); |
1731 | send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END); |
1732 | do { crReturnV; } while (!ispkt); |
1733 | if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) { |
8d5de777 |
1734 | bombout(("Protocol confusion")); |
1735 | crReturnV; |
dacbd0e8 |
1736 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
1737 | logevent("Agent forwarding refused"); |
db7d555c |
1738 | } else { |
dacbd0e8 |
1739 | logevent("Agent forwarding enabled"); |
db7d555c |
1740 | ssh_agentfwd_enabled = TRUE; |
1741 | } |
dacbd0e8 |
1742 | } |
1743 | |
fef97f43 |
1744 | if (!cfg.nopty) { |
e5574168 |
1745 | send_packet(SSH1_CMSG_REQUEST_PTY, |
fb09bf1c |
1746 | PKT_STR, cfg.termtype, |
1747 | PKT_INT, rows, PKT_INT, cols, |
1748 | PKT_INT, 0, PKT_INT, 0, |
1749 | PKT_CHAR, 0, |
1750 | PKT_END); |
fef97f43 |
1751 | ssh_state = SSH_STATE_INTERMED; |
1752 | do { crReturnV; } while (!ispkt); |
e5574168 |
1753 | if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) { |
8d5de777 |
1754 | bombout(("Protocol confusion")); |
1755 | crReturnV; |
e5574168 |
1756 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
fef97f43 |
1757 | c_write("Server refused to allocate pty\r\n", 32); |
1758 | } |
c5e9c988 |
1759 | logevent("Allocated pty"); |
374330e2 |
1760 | } |
1761 | |
4ba9b64b |
1762 | if (cfg.compression) { |
1763 | send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END); |
1764 | do { crReturnV; } while (!ispkt); |
1765 | if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) { |
1766 | bombout(("Protocol confusion")); |
1767 | crReturnV; |
1768 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
1769 | c_write("Server refused to compress\r\n", 32); |
1770 | } |
1771 | logevent("Started compression"); |
1772 | ssh1_compressing = TRUE; |
1773 | zlib_compress_init(); |
1774 | zlib_decompress_init(); |
1775 | } |
1776 | |
6abbf9e3 |
1777 | if (*cfg.remote_cmd) |
1778 | send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END); |
1779 | else |
1780 | send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END); |
c5e9c988 |
1781 | logevent("Started session"); |
374330e2 |
1782 | |
1783 | ssh_state = SSH_STATE_SESSION; |
1784 | if (size_needed) |
1785 | ssh_size(); |
1786 | |
8ccc75b0 |
1787 | ssh_send_ok = 1; |
dacbd0e8 |
1788 | ssh_channels = newtree234(ssh_channelcmp); |
6f34e365 |
1789 | begin_session(); |
374330e2 |
1790 | while (1) { |
1791 | crReturnV; |
1792 | if (ispkt) { |
e5574168 |
1793 | if (pktin.type == SSH1_SMSG_STDOUT_DATA || |
1794 | pktin.type == SSH1_SMSG_STDERR_DATA) { |
fb09bf1c |
1795 | long len = GET_32BIT(pktin.body); |
fe50e814 |
1796 | from_backend(pktin.type == SSH1_SMSG_STDERR_DATA, |
1797 | pktin.body+4, len); |
e5574168 |
1798 | } else if (pktin.type == SSH1_MSG_DISCONNECT) { |
21248260 |
1799 | ssh_state = SSH_STATE_CLOSED; |
c5e9c988 |
1800 | logevent("Received disconnect request"); |
3257deae |
1801 | crReturnV; |
dacbd0e8 |
1802 | } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) { |
1803 | /* Remote side is trying to open a channel to talk to our |
1804 | * agent. Give them back a local channel number. */ |
db7d555c |
1805 | unsigned i; |
dacbd0e8 |
1806 | struct ssh_channel *c; |
1807 | enum234 e; |
db7d555c |
1808 | |
1809 | /* Refuse if agent forwarding is disabled. */ |
1810 | if (!ssh_agentfwd_enabled) { |
1811 | send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE, |
1812 | PKT_INT, GET_32BIT(pktin.body), |
1813 | PKT_END); |
1814 | } else { |
1815 | i = 1; |
1816 | for (c = first234(ssh_channels, &e); c; c = next234(&e)) { |
1817 | if (c->localid > i) |
1818 | break; /* found a free number */ |
1819 | i = c->localid + 1; |
1820 | } |
dcbde236 |
1821 | c = smalloc(sizeof(struct ssh_channel)); |
db7d555c |
1822 | c->remoteid = GET_32BIT(pktin.body); |
1823 | c->localid = i; |
1824 | c->closes = 0; |
1825 | c->type = SSH1_SMSG_AGENT_OPEN;/* identify channel type */ |
1826 | c->u.a.lensofar = 0; |
1827 | add234(ssh_channels, c); |
1828 | send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, |
1829 | PKT_INT, c->remoteid, PKT_INT, c->localid, |
1830 | PKT_END); |
1831 | } |
1832 | } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE || |
1833 | pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) { |
dacbd0e8 |
1834 | /* Remote side closes a channel. */ |
d211621f |
1835 | unsigned i = GET_32BIT(pktin.body); |
dacbd0e8 |
1836 | struct ssh_channel *c; |
1837 | c = find234(ssh_channels, &i, ssh_channelfind); |
1838 | if (c) { |
1839 | int closetype; |
1840 | closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2); |
1841 | send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END); |
1842 | c->closes |= closetype; |
1843 | if (c->closes == 3) { |
1844 | del234(ssh_channels, c); |
dcbde236 |
1845 | sfree(c); |
dacbd0e8 |
1846 | } |
1847 | } |
1848 | } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) { |
1849 | /* Data sent down one of our channels. */ |
1850 | int i = GET_32BIT(pktin.body); |
1851 | int len = GET_32BIT(pktin.body+4); |
1852 | unsigned char *p = pktin.body+8; |
1853 | struct ssh_channel *c; |
1854 | c = find234(ssh_channels, &i, ssh_channelfind); |
1855 | if (c) { |
1856 | switch(c->type) { |
1857 | case SSH1_SMSG_AGENT_OPEN: |
1858 | /* Data for an agent message. Buffer it. */ |
1859 | while (len > 0) { |
1860 | if (c->u.a.lensofar < 4) { |
1861 | int l = min(4 - c->u.a.lensofar, len); |
1862 | memcpy(c->u.a.msglen + c->u.a.lensofar, p, l); |
1863 | p += l; len -= l; c->u.a.lensofar += l; |
1864 | } |
1865 | if (c->u.a.lensofar == 4) { |
1866 | c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen); |
dcbde236 |
1867 | c->u.a.message = smalloc(c->u.a.totallen); |
dacbd0e8 |
1868 | memcpy(c->u.a.message, c->u.a.msglen, 4); |
1869 | } |
1870 | if (c->u.a.lensofar >= 4 && len > 0) { |
1871 | int l = min(c->u.a.totallen - c->u.a.lensofar, len); |
1872 | memcpy(c->u.a.message + c->u.a.lensofar, p, l); |
1873 | p += l; len -= l; c->u.a.lensofar += l; |
1874 | } |
1875 | if (c->u.a.lensofar == c->u.a.totallen) { |
1876 | void *reply, *sentreply; |
1877 | int replylen; |
1878 | agent_query(c->u.a.message, c->u.a.totallen, |
1879 | &reply, &replylen); |
1880 | if (reply) |
1881 | sentreply = reply; |
1882 | else { |
1883 | /* Fake SSH_AGENT_FAILURE. */ |
1884 | sentreply = "\0\0\0\1\5"; |
1885 | replylen = 5; |
1886 | } |
1887 | send_packet(SSH1_MSG_CHANNEL_DATA, |
1888 | PKT_INT, c->remoteid, |
1889 | PKT_INT, replylen, |
1890 | PKT_DATA, sentreply, replylen, |
1891 | PKT_END); |
1892 | if (reply) |
dcbde236 |
1893 | sfree(reply); |
1894 | sfree(c->u.a.message); |
dacbd0e8 |
1895 | c->u.a.lensofar = 0; |
1896 | } |
1897 | } |
1898 | break; |
1899 | } |
1900 | } |
e5574168 |
1901 | } else if (pktin.type == SSH1_SMSG_SUCCESS) { |
972a41c8 |
1902 | /* may be from EXEC_SHELL on some servers */ |
e5574168 |
1903 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
972a41c8 |
1904 | /* may be from EXEC_SHELL on some servers |
374330e2 |
1905 | * if no pty is available or in other odd cases. Ignore */ |
e5574168 |
1906 | } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) { |
1907 | send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END); |
374330e2 |
1908 | } else { |
8d5de777 |
1909 | bombout(("Strange packet received: type %d", pktin.type)); |
1910 | crReturnV; |
374330e2 |
1911 | } |
1912 | } else { |
8df7a775 |
1913 | while (inlen > 0) { |
1914 | int len = min(inlen, 512); |
1915 | send_packet(SSH1_CMSG_STDIN_DATA, |
1916 | PKT_INT, len, PKT_DATA, in, len, PKT_END); |
1917 | in += len; |
1918 | inlen -= len; |
1919 | } |
374330e2 |
1920 | } |
1921 | } |
1922 | |
1923 | crFinishV; |
1924 | } |
1925 | |
1926 | /* |
e5574168 |
1927 | * Utility routine for decoding comma-separated strings in KEXINIT. |
1928 | */ |
75cab814 |
1929 | static int in_commasep_string(char *needle, char *haystack, int haylen) { |
e5574168 |
1930 | int needlen = strlen(needle); |
1931 | while (1) { |
1932 | /* |
1933 | * Is it at the start of the string? |
1934 | */ |
1935 | if (haylen >= needlen && /* haystack is long enough */ |
1936 | !memcmp(needle, haystack, needlen) && /* initial match */ |
1937 | (haylen == needlen || haystack[needlen] == ',') |
1938 | /* either , or EOS follows */ |
1939 | ) |
1940 | return 1; |
1941 | /* |
1942 | * If not, search for the next comma and resume after that. |
1943 | * If no comma found, terminate. |
1944 | */ |
1945 | while (haylen > 0 && *haystack != ',') |
1946 | haylen--, haystack++; |
1947 | if (haylen == 0) |
1948 | return 0; |
1949 | haylen--, haystack++; /* skip over comma itself */ |
1950 | } |
1951 | } |
1952 | |
1953 | /* |
d39f364a |
1954 | * SSH2 key creation method. |
1955 | */ |
75cab814 |
1956 | static void ssh2_mkkey(Bignum K, char *H, char chr, char *keyspace) { |
d39f364a |
1957 | SHA_State s; |
1958 | /* First 20 bytes. */ |
1959 | SHA_Init(&s); |
1960 | sha_mpint(&s, K); |
1961 | SHA_Bytes(&s, H, 20); |
1962 | SHA_Bytes(&s, &chr, 1); |
1963 | SHA_Bytes(&s, H, 20); |
1964 | SHA_Final(&s, keyspace); |
1965 | /* Next 20 bytes. */ |
1966 | SHA_Init(&s); |
1967 | sha_mpint(&s, K); |
1968 | SHA_Bytes(&s, H, 20); |
1969 | SHA_Bytes(&s, keyspace, 20); |
1970 | SHA_Final(&s, keyspace+20); |
1971 | } |
1972 | |
1973 | /* |
7cca0d81 |
1974 | * Handle the SSH2 transport layer. |
e5574168 |
1975 | */ |
7cca0d81 |
1976 | static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt) |
e5574168 |
1977 | { |
1978 | static int i, len; |
1979 | static char *str; |
1980 | static Bignum e, f, K; |
7591b9ff |
1981 | static const struct ssh_mac **maclist; |
8b2715b2 |
1982 | static int nmacs; |
57476f6b |
1983 | static const struct ssh_cipher *cscipher_tobe = NULL; |
1984 | static const struct ssh_cipher *sccipher_tobe = NULL; |
1985 | static const struct ssh_mac *csmac_tobe = NULL; |
1986 | static const struct ssh_mac *scmac_tobe = NULL; |
1987 | static const struct ssh_compress *cscomp_tobe = NULL; |
1988 | static const struct ssh_compress *sccomp_tobe = NULL; |
d5859615 |
1989 | static char *hostkeydata, *sigdata, *keystr, *fingerprint; |
e5574168 |
1990 | static int hostkeylen, siglen; |
e055a386 |
1991 | static void *hkey; /* actual host key */ |
e5574168 |
1992 | static unsigned char exchange_hash[20]; |
d39f364a |
1993 | static unsigned char keyspace[40]; |
57476f6b |
1994 | static const struct ssh_cipher *preferred_cipher; |
4ba9b64b |
1995 | static const struct ssh_compress *preferred_comp; |
e5574168 |
1996 | |
1997 | crBegin; |
7cca0d81 |
1998 | random_init(); |
e5574168 |
1999 | |
5e8358ad |
2000 | /* |
4ba9b64b |
2001 | * Set up the preferred cipher and compression. |
5e8358ad |
2002 | */ |
2003 | if (cfg.cipher == CIPHER_BLOWFISH) { |
57476f6b |
2004 | preferred_cipher = &ssh_blowfish_ssh2; |
5e8358ad |
2005 | } else if (cfg.cipher == CIPHER_DES) { |
2006 | logevent("Single DES not supported in SSH2; using 3DES"); |
57476f6b |
2007 | preferred_cipher = &ssh_3des_ssh2; |
5e8358ad |
2008 | } else if (cfg.cipher == CIPHER_3DES) { |
57476f6b |
2009 | preferred_cipher = &ssh_3des_ssh2; |
5e8358ad |
2010 | } else { |
2011 | /* Shouldn't happen, but we do want to initialise to _something_. */ |
57476f6b |
2012 | preferred_cipher = &ssh_3des_ssh2; |
5e8358ad |
2013 | } |
4ba9b64b |
2014 | if (cfg.compression) |
2015 | preferred_comp = &ssh_zlib; |
2016 | else |
2017 | preferred_comp = &ssh_comp_none; |
5e8358ad |
2018 | |
7591b9ff |
2019 | /* |
2020 | * Be prepared to work around the buggy MAC problem. |
2021 | */ |
2022 | if (cfg.buggymac) |
8b2715b2 |
2023 | maclist = buggymacs, nmacs = lenof(buggymacs); |
7591b9ff |
2024 | else |
8b2715b2 |
2025 | maclist = macs, nmacs = lenof(macs); |
7591b9ff |
2026 | |
7cca0d81 |
2027 | begin_key_exchange: |
e5574168 |
2028 | /* |
2029 | * Construct and send our key exchange packet. |
2030 | */ |
2031 | ssh2_pkt_init(SSH2_MSG_KEXINIT); |
2032 | for (i = 0; i < 16; i++) |
2033 | ssh2_pkt_addbyte((unsigned char)random_byte()); |
2034 | /* List key exchange algorithms. */ |
2035 | ssh2_pkt_addstring_start(); |
2036 | for (i = 0; i < lenof(kex_algs); i++) { |
2037 | ssh2_pkt_addstring_str(kex_algs[i]->name); |
2038 | if (i < lenof(kex_algs)-1) |
2039 | ssh2_pkt_addstring_str(","); |
2040 | } |
2041 | /* List server host key algorithms. */ |
2042 | ssh2_pkt_addstring_start(); |
2043 | for (i = 0; i < lenof(hostkey_algs); i++) { |
2044 | ssh2_pkt_addstring_str(hostkey_algs[i]->name); |
2045 | if (i < lenof(hostkey_algs)-1) |
2046 | ssh2_pkt_addstring_str(","); |
2047 | } |
2048 | /* List client->server encryption algorithms. */ |
2049 | ssh2_pkt_addstring_start(); |
729e54b4 |
2050 | for (i = 0; i < lenof(ciphers)+1; i++) { |
2051 | const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1]; |
57476f6b |
2052 | ssh2_pkt_addstring_str(c->name); |
729e54b4 |
2053 | if (i < lenof(ciphers)) |
e5574168 |
2054 | ssh2_pkt_addstring_str(","); |
2055 | } |
2056 | /* List server->client encryption algorithms. */ |
2057 | ssh2_pkt_addstring_start(); |
729e54b4 |
2058 | for (i = 0; i < lenof(ciphers)+1; i++) { |
2059 | const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1]; |
57476f6b |
2060 | ssh2_pkt_addstring_str(c->name); |
729e54b4 |
2061 | if (i < lenof(ciphers)) |
e5574168 |
2062 | ssh2_pkt_addstring_str(","); |
2063 | } |
2064 | /* List client->server MAC algorithms. */ |
2065 | ssh2_pkt_addstring_start(); |
8b2715b2 |
2066 | for (i = 0; i < nmacs; i++) { |
7591b9ff |
2067 | ssh2_pkt_addstring_str(maclist[i]->name); |
8b2715b2 |
2068 | if (i < nmacs-1) |
e5574168 |
2069 | ssh2_pkt_addstring_str(","); |
2070 | } |
2071 | /* List server->client MAC algorithms. */ |
2072 | ssh2_pkt_addstring_start(); |
8b2715b2 |
2073 | for (i = 0; i < nmacs; i++) { |
7591b9ff |
2074 | ssh2_pkt_addstring_str(maclist[i]->name); |
8b2715b2 |
2075 | if (i < nmacs-1) |
e5574168 |
2076 | ssh2_pkt_addstring_str(","); |
2077 | } |
2078 | /* List client->server compression algorithms. */ |
2079 | ssh2_pkt_addstring_start(); |
4ba9b64b |
2080 | for (i = 0; i < lenof(compressions)+1; i++) { |
2081 | const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1]; |
2082 | ssh2_pkt_addstring_str(c->name); |
2083 | if (i < lenof(compressions)) |
e5574168 |
2084 | ssh2_pkt_addstring_str(","); |
2085 | } |
2086 | /* List server->client compression algorithms. */ |
2087 | ssh2_pkt_addstring_start(); |
4ba9b64b |
2088 | for (i = 0; i < lenof(compressions)+1; i++) { |
2089 | const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1]; |
2090 | ssh2_pkt_addstring_str(c->name); |
2091 | if (i < lenof(compressions)) |
e5574168 |
2092 | ssh2_pkt_addstring_str(","); |
2093 | } |
2094 | /* List client->server languages. Empty list. */ |
2095 | ssh2_pkt_addstring_start(); |
2096 | /* List server->client languages. Empty list. */ |
2097 | ssh2_pkt_addstring_start(); |
2098 | /* First KEX packet does _not_ follow, because we're not that brave. */ |
2099 | ssh2_pkt_addbool(FALSE); |
2100 | /* Reserved. */ |
2101 | ssh2_pkt_adduint32(0); |
2102 | sha_string(&exhash, pktout.data+5, pktout.length-5); |
2103 | ssh2_pkt_send(); |
2104 | |
2105 | if (!ispkt) crWaitUntil(ispkt); |
2106 | sha_string(&exhash, pktin.data+5, pktin.length-5); |
2107 | |
2108 | /* |
2109 | * Now examine the other side's KEXINIT to see what we're up |
2110 | * to. |
2111 | */ |
7cca0d81 |
2112 | if (pktin.type != SSH2_MSG_KEXINIT) { |
8d5de777 |
2113 | bombout(("expected key exchange packet from server")); |
2114 | crReturn(0); |
7cca0d81 |
2115 | } |
e5574168 |
2116 | kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL; |
2117 | csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL; |
2118 | pktin.savedpos += 16; /* skip garbage cookie */ |
2119 | ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */ |
2120 | for (i = 0; i < lenof(kex_algs); i++) { |
2121 | if (in_commasep_string(kex_algs[i]->name, str, len)) { |
2122 | kex = kex_algs[i]; |
2123 | break; |
2124 | } |
2125 | } |
2126 | ssh2_pkt_getstring(&str, &len); /* host key algorithms */ |
2127 | for (i = 0; i < lenof(hostkey_algs); i++) { |
2128 | if (in_commasep_string(hostkey_algs[i]->name, str, len)) { |
2129 | hostkey = hostkey_algs[i]; |
2130 | break; |
2131 | } |
2132 | } |
2133 | ssh2_pkt_getstring(&str, &len); /* client->server cipher */ |
729e54b4 |
2134 | for (i = 0; i < lenof(ciphers)+1; i++) { |
2135 | const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1]; |
57476f6b |
2136 | if (in_commasep_string(c->name, str, len)) { |
729e54b4 |
2137 | cscipher_tobe = c; |
e5574168 |
2138 | break; |
2139 | } |
2140 | } |
2141 | ssh2_pkt_getstring(&str, &len); /* server->client cipher */ |
729e54b4 |
2142 | for (i = 0; i < lenof(ciphers)+1; i++) { |
2143 | const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1]; |
57476f6b |
2144 | if (in_commasep_string(c->name, str, len)) { |
729e54b4 |
2145 | sccipher_tobe = c; |
e5574168 |
2146 | break; |
2147 | } |
2148 | } |
2149 | ssh2_pkt_getstring(&str, &len); /* client->server mac */ |
8b2715b2 |
2150 | for (i = 0; i < nmacs; i++) { |
7591b9ff |
2151 | if (in_commasep_string(maclist[i]->name, str, len)) { |
2152 | csmac_tobe = maclist[i]; |
e5574168 |
2153 | break; |
2154 | } |
2155 | } |
2156 | ssh2_pkt_getstring(&str, &len); /* server->client mac */ |
8b2715b2 |
2157 | for (i = 0; i < nmacs; i++) { |
7591b9ff |
2158 | if (in_commasep_string(maclist[i]->name, str, len)) { |
2159 | scmac_tobe = maclist[i]; |
e5574168 |
2160 | break; |
2161 | } |
2162 | } |
2163 | ssh2_pkt_getstring(&str, &len); /* client->server compression */ |
4ba9b64b |
2164 | for (i = 0; i < lenof(compressions)+1; i++) { |
2165 | const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1]; |
2166 | if (in_commasep_string(c->name, str, len)) { |
2167 | cscomp_tobe = c; |
e5574168 |
2168 | break; |
2169 | } |
2170 | } |
2171 | ssh2_pkt_getstring(&str, &len); /* server->client compression */ |
4ba9b64b |
2172 | for (i = 0; i < lenof(compressions)+1; i++) { |
2173 | const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1]; |
2174 | if (in_commasep_string(c->name, str, len)) { |
2175 | sccomp_tobe = c; |
e5574168 |
2176 | break; |
2177 | } |
2178 | } |
e5574168 |
2179 | |
2180 | /* |
2181 | * Currently we only support Diffie-Hellman and DSS, so let's |
2182 | * bomb out if those aren't selected. |
2183 | */ |
8d5de777 |
2184 | if (kex != &ssh_diffiehellman || hostkey != &ssh_dss) { |
2185 | bombout(("internal fault: chaos in SSH 2 transport layer")); |
2186 | crReturn(0); |
2187 | } |
e5574168 |
2188 | |
2189 | /* |
2190 | * Now we begin the fun. Generate and send e for Diffie-Hellman. |
2191 | */ |
2192 | e = dh_create_e(); |
e5574168 |
2193 | ssh2_pkt_init(SSH2_MSG_KEXDH_INIT); |
2194 | ssh2_pkt_addmp(e); |
2195 | ssh2_pkt_send(); |
2196 | |
2197 | crWaitUntil(ispkt); |
7cca0d81 |
2198 | if (pktin.type != SSH2_MSG_KEXDH_REPLY) { |
8d5de777 |
2199 | bombout(("expected key exchange packet from server")); |
2200 | crReturn(0); |
7cca0d81 |
2201 | } |
e5574168 |
2202 | ssh2_pkt_getstring(&hostkeydata, &hostkeylen); |
2203 | f = ssh2_pkt_getmp(); |
e5574168 |
2204 | ssh2_pkt_getstring(&sigdata, &siglen); |
2205 | |
2206 | K = dh_find_K(f); |
e5574168 |
2207 | |
2208 | sha_string(&exhash, hostkeydata, hostkeylen); |
2209 | sha_mpint(&exhash, e); |
2210 | sha_mpint(&exhash, f); |
2211 | sha_mpint(&exhash, K); |
2212 | SHA_Final(&exhash, exchange_hash); |
2213 | |
7cca0d81 |
2214 | #if 0 |
e5574168 |
2215 | debug(("Exchange hash is:\r\n")); |
2216 | for (i = 0; i < 20; i++) |
2217 | debug((" %02x", exchange_hash[i])); |
2218 | debug(("\r\n")); |
7cca0d81 |
2219 | #endif |
2220 | |
e055a386 |
2221 | hkey = hostkey->newkey(hostkeydata, hostkeylen); |
2222 | if (!hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) { |
8d5de777 |
2223 | bombout(("Server failed host key check")); |
2224 | crReturn(0); |
2225 | } |
e5574168 |
2226 | |
2227 | /* |
7cca0d81 |
2228 | * Expect SSH2_MSG_NEWKEYS from server. |
d39f364a |
2229 | */ |
7cca0d81 |
2230 | crWaitUntil(ispkt); |
8d5de777 |
2231 | if (pktin.type != SSH2_MSG_NEWKEYS) { |
2232 | bombout(("expected new-keys packet from server")); |
2233 | crReturn(0); |
2234 | } |
d39f364a |
2235 | |
2236 | /* |
7cca0d81 |
2237 | * Authenticate remote host: verify host key. (We've already |
2238 | * checked the signature of the exchange hash.) |
e5574168 |
2239 | */ |
e055a386 |
2240 | keystr = hostkey->fmtkey(hkey); |
2241 | fingerprint = hostkey->fingerprint(hkey); |
d4857987 |
2242 | verify_ssh_host_key(savedhost, savedport, hostkey->keytype, |
2243 | keystr, fingerprint); |
d5859615 |
2244 | logevent("Host key fingerprint is:"); |
2245 | logevent(fingerprint); |
dcbde236 |
2246 | sfree(fingerprint); |
2247 | sfree(keystr); |
e055a386 |
2248 | hostkey->freekey(hkey); |
d39f364a |
2249 | |
2250 | /* |
7cca0d81 |
2251 | * Send SSH2_MSG_NEWKEYS. |
d39f364a |
2252 | */ |
2253 | ssh2_pkt_init(SSH2_MSG_NEWKEYS); |
2254 | ssh2_pkt_send(); |
d39f364a |
2255 | |
2256 | /* |
2257 | * Create and initialise session keys. |
2258 | */ |
2259 | cscipher = cscipher_tobe; |
2260 | sccipher = sccipher_tobe; |
2261 | csmac = csmac_tobe; |
2262 | scmac = scmac_tobe; |
2263 | cscomp = cscomp_tobe; |
2264 | sccomp = sccomp_tobe; |
4ba9b64b |
2265 | cscomp->compress_init(); |
2266 | sccomp->decompress_init(); |
d39f364a |
2267 | /* |
2268 | * Set IVs after keys. |
2269 | */ |
2270 | ssh2_mkkey(K, exchange_hash, 'C', keyspace); cscipher->setcskey(keyspace); |
2271 | ssh2_mkkey(K, exchange_hash, 'D', keyspace); cscipher->setsckey(keyspace); |
2272 | ssh2_mkkey(K, exchange_hash, 'A', keyspace); cscipher->setcsiv(keyspace); |
2273 | ssh2_mkkey(K, exchange_hash, 'B', keyspace); sccipher->setsciv(keyspace); |
2274 | ssh2_mkkey(K, exchange_hash, 'E', keyspace); csmac->setcskey(keyspace); |
2275 | ssh2_mkkey(K, exchange_hash, 'F', keyspace); scmac->setsckey(keyspace); |
2276 | |
033b4cef |
2277 | /* |
7cca0d81 |
2278 | * Now we're encrypting. Begin returning 1 to the protocol main |
2279 | * function so that other things can run on top of the |
2280 | * transport. If we ever see a KEXINIT, we must go back to the |
2281 | * start. |
033b4cef |
2282 | */ |
7cca0d81 |
2283 | do { |
2284 | crReturn(1); |
2285 | } while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)); |
2286 | goto begin_key_exchange; |
e5574168 |
2287 | |
2288 | crFinish(1); |
2289 | } |
2290 | |
7cca0d81 |
2291 | /* |
2292 | * Handle the SSH2 userauth and connection layers. |
2293 | */ |
2294 | static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) |
2295 | { |
7cca0d81 |
2296 | static unsigned long remote_winsize; |
2297 | static unsigned long remote_maxpkt; |
2298 | |
e5574168 |
2299 | crBegin; |
2300 | |
7cca0d81 |
2301 | /* |
2302 | * Request userauth protocol, and await a response to it. |
2303 | */ |
2304 | ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST); |
2305 | ssh2_pkt_addstring("ssh-userauth"); |
2306 | ssh2_pkt_send(); |
2307 | crWaitUntilV(ispkt); |
8d5de777 |
2308 | if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) { |
2309 | bombout(("Server refused user authentication protocol")); |
2310 | crReturnV; |
2311 | } |
7cca0d81 |
2312 | |
2313 | /* |
2314 | * FIXME: currently we support only password authentication. |
2315 | * (This places us technically in violation of the SSH2 spec. |
2316 | * We must fix this.) |
2317 | */ |
2318 | while (1) { |
2319 | /* |
2320 | * Get a username and a password. |
2321 | */ |
2322 | static char username[100]; |
2323 | static char password[100]; |
2324 | static int pos = 0; |
2325 | static char c; |
e5574168 |
2326 | |
67779be7 |
2327 | if ((flags & FLAG_INTERACTIVE) && !*cfg.username) { |
7cca0d81 |
2328 | c_write("login as: ", 10); |
67779be7 |
2329 | ssh_send_ok = 1; |
7cca0d81 |
2330 | while (pos >= 0) { |
2331 | crWaitUntilV(!ispkt); |
2332 | while (inlen--) switch (c = *in++) { |
2333 | case 10: case 13: |
2334 | username[pos] = 0; |
2335 | pos = -1; |
2336 | break; |
2337 | case 8: case 127: |
2338 | if (pos > 0) { |
2339 | c_write("\b \b", 3); |
2340 | pos--; |
2341 | } |
2342 | break; |
2343 | case 21: case 27: |
2344 | while (pos > 0) { |
2345 | c_write("\b \b", 3); |
2346 | pos--; |
2347 | } |
2348 | break; |
2349 | case 3: case 4: |
2350 | random_save_seed(); |
2351 | exit(0); |
2352 | break; |
2353 | default: |
2354 | if (((c >= ' ' && c <= '~') || |
2355 | ((unsigned char)c >= 160)) && pos < 40) { |
2356 | username[pos++] = c; |
2357 | c_write(&c, 1); |
2358 | } |
2359 | break; |
2360 | } |
2361 | } |
2362 | c_write("\r\n", 2); |
2363 | username[strcspn(username, "\n\r")] = '\0'; |
2364 | } else { |
2365 | char stuff[200]; |
2366 | strncpy(username, cfg.username, 99); |
2367 | username[99] = '\0'; |
67779be7 |
2368 | if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) { |
7cca0d81 |
2369 | sprintf(stuff, "Using username \"%s\".\r\n", username); |
2370 | c_write(stuff, strlen(stuff)); |
2371 | } |
2372 | } |
2373 | |
d8426c54 |
2374 | if (ssh_get_password) { |
7cca0d81 |
2375 | char prompt[200]; |
b585ec46 |
2376 | sprintf(prompt, "%.90s@%.90s's password: ", username, savedhost); |
7cca0d81 |
2377 | if (!ssh_get_password(prompt, password, sizeof(password))) { |
2378 | /* |
2379 | * get_password failed to get a password (for |
2380 | * example because one was supplied on the command |
2381 | * line which has already failed to work). |
2382 | * Terminate. |
2383 | */ |
2384 | logevent("No more passwords to try"); |
2385 | ssh_state = SSH_STATE_CLOSED; |
2386 | crReturnV; |
2387 | } |
2388 | } else { |
2389 | c_write("password: ", 10); |
67779be7 |
2390 | ssh_send_ok = 1; |
7cca0d81 |
2391 | |
2392 | pos = 0; |
2393 | while (pos >= 0) { |
2394 | crWaitUntilV(!ispkt); |
2395 | while (inlen--) switch (c = *in++) { |
2396 | case 10: case 13: |
2397 | password[pos] = 0; |
2398 | pos = -1; |
2399 | break; |
2400 | case 8: case 127: |
2401 | if (pos > 0) |
2402 | pos--; |
2403 | break; |
2404 | case 21: case 27: |
2405 | pos = 0; |
2406 | break; |
2407 | case 3: case 4: |
2408 | random_save_seed(); |
2409 | exit(0); |
2410 | break; |
2411 | default: |
2412 | if (((c >= ' ' && c <= '~') || |
2413 | ((unsigned char)c >= 160)) && pos < 40) |
2414 | password[pos++] = c; |
2415 | break; |
2416 | } |
2417 | } |
2418 | c_write("\r\n", 2); |
2419 | } |
2420 | |
2421 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
2422 | ssh2_pkt_addstring(username); |
2423 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
2424 | ssh2_pkt_addstring("password"); |
2425 | ssh2_pkt_addbool(FALSE); |
2426 | ssh2_pkt_addstring(password); |
2427 | ssh2_pkt_send(); |
2428 | |
2429 | crWaitUntilV(ispkt); |
2430 | if (pktin.type != SSH2_MSG_USERAUTH_SUCCESS) { |
2431 | c_write("Access denied\r\n", 15); |
2432 | logevent("Authentication refused"); |
2433 | } else |
2434 | break; |
2435 | } |
2436 | |
2437 | /* |
2438 | * Now we're authenticated for the connection protocol. The |
2439 | * connection protocol will automatically have started at this |
2440 | * point; there's no need to send SERVICE_REQUEST. |
2441 | */ |
2442 | |
2443 | /* |
2444 | * So now create a channel with a session in it. |
2445 | */ |
dcbde236 |
2446 | mainchan = smalloc(sizeof(struct ssh_channel)); |
d211621f |
2447 | mainchan->localid = 100; /* as good as any */ |
7cca0d81 |
2448 | ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN); |
2449 | ssh2_pkt_addstring("session"); |
d211621f |
2450 | ssh2_pkt_adduint32(mainchan->localid); |
cf6e59d6 |
2451 | ssh2_pkt_adduint32(0x8000UL); /* our window size */ |
d211621f |
2452 | ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */ |
7cca0d81 |
2453 | ssh2_pkt_send(); |
2454 | crWaitUntilV(ispkt); |
2455 | if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) { |
8d5de777 |
2456 | bombout(("Server refused to open a session")); |
2457 | crReturnV; |
7cca0d81 |
2458 | /* FIXME: error data comes back in FAILURE packet */ |
2459 | } |
d211621f |
2460 | if (ssh2_pkt_getuint32() != mainchan->localid) { |
8d5de777 |
2461 | bombout(("Server's channel confirmation cited wrong channel")); |
2462 | crReturnV; |
7cca0d81 |
2463 | } |
d211621f |
2464 | mainchan->remoteid = ssh2_pkt_getuint32(); |
2465 | mainchan->u.v2.remwindow = ssh2_pkt_getuint32(); |
2466 | mainchan->u.v2.remmaxpkt = ssh2_pkt_getuint32(); |
2467 | mainchan->u.v2.outbuffer = NULL; |
2468 | mainchan->u.v2.outbuflen = mainchan->u.v2.outbufsize = 0; |
7cca0d81 |
2469 | logevent("Opened channel for session"); |
2470 | |
2471 | /* |
2472 | * Now allocate a pty for the session. |
2473 | */ |
67779be7 |
2474 | if (!cfg.nopty) { |
2475 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
2476 | ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */ |
2477 | ssh2_pkt_addstring("pty-req"); |
2478 | ssh2_pkt_addbool(1); /* want reply */ |
2479 | ssh2_pkt_addstring(cfg.termtype); |
2480 | ssh2_pkt_adduint32(cols); |
2481 | ssh2_pkt_adduint32(rows); |
2482 | ssh2_pkt_adduint32(0); /* pixel width */ |
2483 | ssh2_pkt_adduint32(0); /* pixel height */ |
2484 | ssh2_pkt_addstring_start(); |
2485 | ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */ |
2486 | ssh2_pkt_send(); |
6e48c3fe |
2487 | ssh_state = SSH_STATE_INTERMED; |
7cca0d81 |
2488 | |
67779be7 |
2489 | do { |
2490 | crWaitUntilV(ispkt); |
2491 | if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
2492 | /* FIXME: be able to handle other channels here */ |
2493 | if (ssh2_pkt_getuint32() != mainchan->localid) |
2494 | continue; /* wrong channel */ |
2495 | mainchan->u.v2.remwindow += ssh2_pkt_getuint32(); |
2496 | } |
2497 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
7cca0d81 |
2498 | |
67779be7 |
2499 | if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
2500 | if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
8d5de777 |
2501 | bombout(("Server got confused by pty request")); |
2502 | crReturnV; |
67779be7 |
2503 | } |
2504 | c_write("Server refused to allocate pty\r\n", 32); |
2505 | } else { |
2506 | logevent("Allocated pty"); |
7cca0d81 |
2507 | } |
7cca0d81 |
2508 | } |
2509 | |
2510 | /* |
67779be7 |
2511 | * Start a shell or a remote command. |
7cca0d81 |
2512 | */ |
2513 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
d211621f |
2514 | ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */ |
67779be7 |
2515 | if (*cfg.remote_cmd) { |
2516 | ssh2_pkt_addstring("exec"); |
2517 | ssh2_pkt_addbool(1); /* want reply */ |
2518 | ssh2_pkt_addstring(cfg.remote_cmd); |
2519 | } else { |
2520 | ssh2_pkt_addstring("shell"); |
2521 | ssh2_pkt_addbool(1); /* want reply */ |
2522 | } |
7cca0d81 |
2523 | ssh2_pkt_send(); |
d211621f |
2524 | do { |
7cca0d81 |
2525 | crWaitUntilV(ispkt); |
d211621f |
2526 | if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
2527 | /* FIXME: be able to handle other channels here */ |
2528 | if (ssh2_pkt_getuint32() != mainchan->localid) |
2529 | continue; /* wrong channel */ |
2530 | mainchan->u.v2.remwindow += ssh2_pkt_getuint32(); |
2531 | } |
7cca0d81 |
2532 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
2533 | if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
2534 | if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
8d5de777 |
2535 | bombout(("Server got confused by shell/command request")); |
2536 | crReturnV; |
7cca0d81 |
2537 | } |
8d5de777 |
2538 | bombout(("Server refused to start a shell/command")); |
2539 | crReturnV; |
7cca0d81 |
2540 | } else { |
8d5de777 |
2541 | logevent("Started a shell/command"); |
7cca0d81 |
2542 | } |
2543 | |
6e48c3fe |
2544 | ssh_state = SSH_STATE_SESSION; |
2545 | if (size_needed) |
2546 | ssh_size(); |
2547 | |
7cca0d81 |
2548 | /* |
2549 | * Transfer data! |
2550 | */ |
8ccc75b0 |
2551 | ssh_send_ok = 1; |
6f34e365 |
2552 | begin_session(); |
7cca0d81 |
2553 | while (1) { |
d211621f |
2554 | static int try_send; |
e5574168 |
2555 | crReturnV; |
d211621f |
2556 | try_send = FALSE; |
7cca0d81 |
2557 | if (ispkt) { |
2558 | if (pktin.type == SSH2_MSG_CHANNEL_DATA || |
2559 | pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) { |
2560 | char *data; |
2561 | int length; |
d211621f |
2562 | /* FIXME: be able to handle other channels here */ |
2563 | if (ssh2_pkt_getuint32() != mainchan->localid) |
7cca0d81 |
2564 | continue; /* wrong channel */ |
2565 | if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA && |
2566 | ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR) |
2567 | continue; /* extended but not stderr */ |
2568 | ssh2_pkt_getstring(&data, &length); |
d211621f |
2569 | if (data) { |
fe50e814 |
2570 | from_backend(pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA, |
2571 | data, length); |
d211621f |
2572 | /* |
2573 | * Enlarge the window again at the remote side, |
2574 | * just in case it ever runs down and they fail |
2575 | * to send us any more data. |
2576 | */ |
2577 | ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
2578 | ssh2_pkt_adduint32(mainchan->remoteid); |
2579 | ssh2_pkt_adduint32(length); |
2580 | ssh2_pkt_send(); |
2581 | } |
7cca0d81 |
2582 | } else if (pktin.type == SSH2_MSG_DISCONNECT) { |
2583 | ssh_state = SSH_STATE_CLOSED; |
d211621f |
2584 | logevent("Received disconnect message"); |
3257deae |
2585 | crReturnV; |
7cca0d81 |
2586 | } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) { |
2587 | continue; /* exit status et al; ignore (FIXME?) */ |
d211621f |
2588 | } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) { |
2589 | continue; /* remote sends EOF; ignore */ |
2590 | } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) { |
2591 | /* FIXME: be able to handle other channels here */ |
2592 | if (ssh2_pkt_getuint32() != mainchan->localid) |
2593 | continue; /* wrong channel */ |
2594 | ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); |
2595 | ssh2_pkt_adduint32(mainchan->remoteid); |
2596 | ssh2_pkt_send(); |
2597 | /* FIXME: mark the channel as closed */ |
2598 | if (1 /* FIXME: "all channels are closed" */) { |
2599 | logevent("All channels closed. Disconnecting"); |
2600 | ssh2_pkt_init(SSH2_MSG_DISCONNECT); |
9005f3ba |
2601 | ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION); |
2602 | ssh2_pkt_addstring("All open channels closed"); |
2603 | ssh2_pkt_addstring("en"); /* language tag */ |
d211621f |
2604 | ssh2_pkt_send(); |
cf6e59d6 |
2605 | ssh_state = SSH_STATE_CLOSED; |
3257deae |
2606 | crReturnV; |
d211621f |
2607 | } |
2608 | continue; /* remote sends close; ignore (FIXME) */ |
7cca0d81 |
2609 | } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
d211621f |
2610 | /* FIXME: be able to handle other channels here */ |
2611 | if (ssh2_pkt_getuint32() != mainchan->localid) |
2612 | continue; /* wrong channel */ |
2613 | mainchan->u.v2.remwindow += ssh2_pkt_getuint32(); |
2614 | try_send = TRUE; |
7cca0d81 |
2615 | } else { |
8d5de777 |
2616 | bombout(("Strange packet received: type %d", pktin.type)); |
2617 | crReturnV; |
7cca0d81 |
2618 | } |
2619 | } else { |
d211621f |
2620 | /* |
2621 | * We have spare data. Add it to the channel buffer. |
2622 | */ |
2623 | if (mainchan->u.v2.outbufsize < |
2624 | mainchan->u.v2.outbuflen + inlen) { |
2625 | mainchan->u.v2.outbufsize = |
2626 | mainchan->u.v2.outbuflen + inlen + 1024; |
2627 | mainchan->u.v2.outbuffer = srealloc(mainchan->u.v2.outbuffer, |
2628 | mainchan->u.v2.outbufsize); |
2629 | } |
2630 | memcpy(mainchan->u.v2.outbuffer + mainchan->u.v2.outbuflen, |
2631 | in, inlen); |
2632 | mainchan->u.v2.outbuflen += inlen; |
2633 | try_send = TRUE; |
7cca0d81 |
2634 | } |
d211621f |
2635 | if (try_send) { |
2636 | /* |
2637 | * Try to send data on the channel if we can. (FIXME: |
2638 | * on _all_ channels.) |
2639 | */ |
2640 | while (mainchan->u.v2.remwindow > 0 && |
2641 | mainchan->u.v2.outbuflen > 0) { |
2642 | unsigned len = mainchan->u.v2.remwindow; |
2643 | if (len > mainchan->u.v2.outbuflen) |
2644 | len = mainchan->u.v2.outbuflen; |
2645 | if (len > mainchan->u.v2.remmaxpkt) |
2646 | len = mainchan->u.v2.remmaxpkt; |
2647 | ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA); |
2648 | ssh2_pkt_adduint32(mainchan->remoteid); |
2649 | ssh2_pkt_addstring_start(); |
2650 | ssh2_pkt_addstring_data(mainchan->u.v2.outbuffer, len); |
2651 | ssh2_pkt_send(); |
2652 | mainchan->u.v2.outbuflen -= len; |
2653 | memmove(mainchan->u.v2.outbuffer, mainchan->u.v2.outbuffer+len, |
2654 | mainchan->u.v2.outbuflen); |
2655 | mainchan->u.v2.remwindow -= len; |
2656 | } |
2657 | } |
e5574168 |
2658 | } |
2659 | |
2660 | crFinishV; |
2661 | } |
2662 | |
2663 | /* |
7cca0d81 |
2664 | * Handle the top-level SSH2 protocol. |
2665 | */ |
2666 | static void ssh2_protocol(unsigned char *in, int inlen, int ispkt) |
2667 | { |
2668 | if (do_ssh2_transport(in, inlen, ispkt) == 0) |
2669 | return; |
2670 | do_ssh2_authconn(in, inlen, ispkt); |
2671 | } |
2672 | |
2673 | /* |
8df7a775 |
2674 | * Called to set up the connection. |
374330e2 |
2675 | * |
2676 | * Returns an error message, or NULL on success. |
374330e2 |
2677 | */ |
8df7a775 |
2678 | static char *ssh_init (char *host, int port, char **realhost) { |
fb09bf1c |
2679 | char *p; |
8f203108 |
2680 | |
2681 | #ifdef MSCRYPTOAPI |
2682 | if(crypto_startup() == 0) |
2683 | return "Microsoft high encryption pack not installed!"; |
2684 | #endif |
374330e2 |
2685 | |
8df7a775 |
2686 | ssh_send_ok = 0; |
2687 | |
fb09bf1c |
2688 | p = connect_to_host(host, port, realhost); |
2689 | if (p != NULL) |
2690 | return p; |
374330e2 |
2691 | |
374330e2 |
2692 | return NULL; |
2693 | } |
2694 | |
2695 | /* |
374330e2 |
2696 | * Called to send data down the Telnet connection. |
2697 | */ |
2698 | static void ssh_send (char *buf, int len) { |
f78051a1 |
2699 | if (s == NULL || ssh_protocol == NULL) |
374330e2 |
2700 | return; |
2701 | |
2702 | ssh_protocol(buf, len, 0); |
2703 | } |
2704 | |
2705 | /* |
6e48c3fe |
2706 | * Called to set the size of the window from SSH's POV. |
374330e2 |
2707 | */ |
2708 | static void ssh_size(void) { |
2709 | switch (ssh_state) { |
2710 | case SSH_STATE_BEFORE_SIZE: |
21248260 |
2711 | case SSH_STATE_CLOSED: |
374330e2 |
2712 | break; /* do nothing */ |
2713 | case SSH_STATE_INTERMED: |
2714 | size_needed = TRUE; /* buffer for later */ |
2715 | break; |
2716 | case SSH_STATE_SESSION: |
fef97f43 |
2717 | if (!cfg.nopty) { |
6e48c3fe |
2718 | if (ssh_version == 1) { |
2719 | send_packet(SSH1_CMSG_WINDOW_SIZE, |
2720 | PKT_INT, rows, PKT_INT, cols, |
2721 | PKT_INT, 0, PKT_INT, 0, PKT_END); |
2722 | } else { |
2723 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
2724 | ssh2_pkt_adduint32(mainchan->remoteid); |
2725 | ssh2_pkt_addstring("window-change"); |
2726 | ssh2_pkt_addbool(0); |
2727 | ssh2_pkt_adduint32(cols); |
2728 | ssh2_pkt_adduint32(rows); |
2729 | ssh2_pkt_adduint32(0); |
2730 | ssh2_pkt_adduint32(0); |
2731 | ssh2_pkt_send(); |
2732 | } |
fef97f43 |
2733 | } |
374330e2 |
2734 | } |
2735 | } |
2736 | |
2737 | /* |
6abbf9e3 |
2738 | * Send Telnet special codes. TS_EOF is useful for `plink', so you |
2739 | * can send an EOF and collect resulting output (e.g. `plink |
2740 | * hostname sort'). |
374330e2 |
2741 | */ |
2742 | static void ssh_special (Telnet_Special code) { |
6abbf9e3 |
2743 | if (code == TS_EOF) { |
67779be7 |
2744 | if (ssh_version == 1) { |
6abbf9e3 |
2745 | send_packet(SSH1_CMSG_EOF, PKT_END); |
2746 | } else { |
2747 | ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF); |
d211621f |
2748 | ssh2_pkt_adduint32(mainchan->remoteid); |
6abbf9e3 |
2749 | ssh2_pkt_send(); |
2750 | } |
67779be7 |
2751 | logevent("Sent EOF message"); |
ec55b220 |
2752 | } else if (code == TS_PING) { |
2753 | if (ssh_version == 1) { |
2754 | send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END); |
2755 | } else { |
2756 | ssh2_pkt_init(SSH2_MSG_IGNORE); |
2757 | ssh2_pkt_addstring_start(); |
2758 | ssh2_pkt_send(); |
2759 | } |
6abbf9e3 |
2760 | } else { |
2761 | /* do nothing */ |
2762 | } |
374330e2 |
2763 | } |
2764 | |
8df7a775 |
2765 | static Socket ssh_socket(void) { return s; } |
8ccc75b0 |
2766 | |
2767 | static int ssh_sendok(void) { return ssh_send_ok; } |
fb09bf1c |
2768 | |
374330e2 |
2769 | Backend ssh_backend = { |
2770 | ssh_init, |
374330e2 |
2771 | ssh_send, |
2772 | ssh_size, |
4017be6d |
2773 | ssh_special, |
8ccc75b0 |
2774 | ssh_socket, |
97db3be4 |
2775 | ssh_sendok, |
2776 | 22 |
374330e2 |
2777 | }; |