diff options
author | Damien Miller <djm@mindrot.org> | 2000-04-29 23:57:08 +1000 |
---|---|---|
committer | Damien Miller <djm@mindrot.org> | 2000-04-29 23:57:08 +1000 |
commit | eba71bab9bf01c0d688f829a8971f902732558df (patch) | |
tree | a9d5b50568bfc10cc50291fd3604debfaf3e3783 /sshconnect2.c | |
parent | 8117111a3c1360727e3c54aad31aa045e7a7871b (diff) |
- Merge big update to OpenSSH-2.0 from OpenBSD CVS
[README.openssh2]
- interop w/ F-secure windows client
- sync documentation
- ssh_host_dsa_key not ssh_dsa_key
[auth-rsa.c]
- missing fclose
[auth.c authfile.c compat.c dsa.c dsa.h hostfile.c key.c key.h radix.c]
[readconf.c readconf.h ssh-add.c ssh-keygen.c ssh.c ssh.h sshconnect.c]
[sshd.c uuencode.c uuencode.h authfile.h]
- add DSA pubkey auth and other SSH2 fixes. use ssh-keygen -[xX]
for trading keys with the real and the original SSH, directly from the
people who invented the SSH protocol.
[auth.c auth.h authfile.c sshconnect.c auth1.c auth2.c sshconnect.h]
[sshconnect1.c sshconnect2.c]
- split auth/sshconnect in one file per protocol version
[sshconnect2.c]
- remove debug
[uuencode.c]
- add trailing =
[version.h]
- OpenSSH-2.0
[ssh-keygen.1 ssh-keygen.c]
- add -R flag: exit code indicates if RSA is alive
[sshd.c]
- remove unused
silent if -Q is specified
[ssh.h]
- host key becomes /etc/ssh_host_dsa_key
[readconf.c servconf.c ]
- ssh/sshd default to proto 1 and 2
[uuencode.c]
- remove debug
[auth2.c ssh-keygen.c sshconnect2.c sshd.c]
- xfree DSA blobs
[auth2.c serverloop.c session.c]
- cleanup logging for sshd/2, respect PasswordAuth no
[sshconnect2.c]
- less debug, respect .ssh/config
[README.openssh2 channels.c channels.h]
- clientloop.c session.c ssh.c
- support for x11-fwding, client+server
Diffstat (limited to 'sshconnect2.c')
-rw-r--r-- | sshconnect2.c | 449 |
1 files changed, 449 insertions, 0 deletions
diff --git a/sshconnect2.c b/sshconnect2.c new file mode 100644 index 000000000..31ef3084c --- /dev/null +++ b/sshconnect2.c | |||
@@ -0,0 +1,449 @@ | |||
1 | /* | ||
2 | * Copyright (c) 2000 Markus Friedl. All rights reserved. | ||
3 | * | ||
4 | * Redistribution and use in source and binary forms, with or without | ||
5 | * modification, are permitted provided that the following conditions | ||
6 | * are met: | ||
7 | * 1. Redistributions of source code must retain the above copyright | ||
8 | * notice, this list of conditions and the following disclaimer. | ||
9 | * 2. Redistributions in binary form must reproduce the above copyright | ||
10 | * notice, this list of conditions and the following disclaimer in the | ||
11 | * documentation and/or other materials provided with the distribution. | ||
12 | * 3. All advertising materials mentioning features or use of this software | ||
13 | * must display the following acknowledgement: | ||
14 | * This product includes software developed by Markus Friedl. | ||
15 | * 4. The name of the author may not be used to endorse or promote products | ||
16 | * derived from this software without specific prior written permission. | ||
17 | * | ||
18 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | ||
19 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | ||
20 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | ||
21 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | ||
22 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | ||
23 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | ||
24 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | ||
25 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | ||
26 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | ||
27 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | ||
28 | */ | ||
29 | |||
30 | #include "includes.h" | ||
31 | RCSID("$OpenBSD: sshconnect2.c,v 1.4 2000/04/27 17:54:01 markus Exp $"); | ||
32 | |||
33 | #include <openssl/bn.h> | ||
34 | #include <openssl/rsa.h> | ||
35 | #include <openssl/dsa.h> | ||
36 | #include <openssl/md5.h> | ||
37 | #include <openssl/dh.h> | ||
38 | #include <openssl/hmac.h> | ||
39 | |||
40 | #include "ssh.h" | ||
41 | #include "xmalloc.h" | ||
42 | #include "rsa.h" | ||
43 | #include "buffer.h" | ||
44 | #include "packet.h" | ||
45 | #include "cipher.h" | ||
46 | #include "uidswap.h" | ||
47 | #include "compat.h" | ||
48 | #include "readconf.h" | ||
49 | #include "bufaux.h" | ||
50 | #include "ssh2.h" | ||
51 | #include "kex.h" | ||
52 | #include "myproposal.h" | ||
53 | #include "key.h" | ||
54 | #include "dsa.h" | ||
55 | #include "sshconnect.h" | ||
56 | #include "authfile.h" | ||
57 | |||
58 | /* import */ | ||
59 | extern char *client_version_string; | ||
60 | extern char *server_version_string; | ||
61 | extern Options options; | ||
62 | |||
63 | /* | ||
64 | * SSH2 key exchange | ||
65 | */ | ||
66 | |||
67 | unsigned char *session_id2 = NULL; | ||
68 | int session_id2_len = 0; | ||
69 | |||
70 | void | ||
71 | ssh_kex2(char *host, struct sockaddr *hostaddr) | ||
72 | { | ||
73 | Kex *kex; | ||
74 | char *cprop[PROPOSAL_MAX]; | ||
75 | char *sprop[PROPOSAL_MAX]; | ||
76 | Buffer *client_kexinit; | ||
77 | Buffer *server_kexinit; | ||
78 | int payload_len, dlen; | ||
79 | unsigned int klen, kout; | ||
80 | char *ptr; | ||
81 | char *signature = NULL; | ||
82 | unsigned int slen; | ||
83 | char *server_host_key_blob = NULL; | ||
84 | Key *server_host_key; | ||
85 | unsigned int sbloblen; | ||
86 | DH *dh; | ||
87 | BIGNUM *dh_server_pub = 0; | ||
88 | BIGNUM *shared_secret = 0; | ||
89 | int i; | ||
90 | unsigned char *kbuf; | ||
91 | unsigned char *hash; | ||
92 | |||
93 | /* KEXINIT */ | ||
94 | |||
95 | debug("Sending KEX init."); | ||
96 | if (options.ciphers != NULL) { | ||
97 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = | ||
98 | myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers; | ||
99 | } else if ( | ||
100 | options.cipher == SSH_CIPHER_ARCFOUR || | ||
101 | options.cipher == SSH_CIPHER_3DES_CBC || | ||
102 | options.cipher == SSH_CIPHER_CAST128_CBC || | ||
103 | options.cipher == SSH_CIPHER_BLOWFISH_CBC) { | ||
104 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = | ||
105 | myproposal[PROPOSAL_ENC_ALGS_STOC] = cipher_name(options.cipher); | ||
106 | } | ||
107 | if (options.compression) { | ||
108 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = "zlib"; | ||
109 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib"; | ||
110 | } else { | ||
111 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = "none"; | ||
112 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "none"; | ||
113 | } | ||
114 | for (i = 0; i < PROPOSAL_MAX; i++) | ||
115 | cprop[i] = xstrdup(myproposal[i]); | ||
116 | |||
117 | client_kexinit = kex_init(cprop); | ||
118 | packet_start(SSH2_MSG_KEXINIT); | ||
119 | packet_put_raw(buffer_ptr(client_kexinit), buffer_len(client_kexinit)); | ||
120 | packet_send(); | ||
121 | packet_write_wait(); | ||
122 | |||
123 | debug("done"); | ||
124 | |||
125 | packet_read_expect(&payload_len, SSH2_MSG_KEXINIT); | ||
126 | |||
127 | /* save payload for session_id */ | ||
128 | server_kexinit = xmalloc(sizeof(*server_kexinit)); | ||
129 | buffer_init(server_kexinit); | ||
130 | ptr = packet_get_raw(&payload_len); | ||
131 | buffer_append(server_kexinit, ptr, payload_len); | ||
132 | |||
133 | /* skip cookie */ | ||
134 | for (i = 0; i < 16; i++) | ||
135 | (void) packet_get_char(); | ||
136 | /* kex init proposal strings */ | ||
137 | for (i = 0; i < PROPOSAL_MAX; i++) { | ||
138 | sprop[i] = packet_get_string(NULL); | ||
139 | debug("got kexinit string: %s", sprop[i]); | ||
140 | } | ||
141 | i = (int) packet_get_char(); | ||
142 | debug("first kex follow == %d", i); | ||
143 | i = packet_get_int(); | ||
144 | debug("reserved == %d", i); | ||
145 | packet_done(); | ||
146 | |||
147 | debug("done read kexinit"); | ||
148 | kex = kex_choose_conf(cprop, sprop, 0); | ||
149 | |||
150 | /* KEXDH */ | ||
151 | |||
152 | debug("Sending SSH2_MSG_KEXDH_INIT."); | ||
153 | |||
154 | /* generate and send 'e', client DH public key */ | ||
155 | dh = dh_new_group1(); | ||
156 | packet_start(SSH2_MSG_KEXDH_INIT); | ||
157 | packet_put_bignum2(dh->pub_key); | ||
158 | packet_send(); | ||
159 | packet_write_wait(); | ||
160 | |||
161 | #ifdef DEBUG_KEXDH | ||
162 | fprintf(stderr, "\np= "); | ||
163 | bignum_print(dh->p); | ||
164 | fprintf(stderr, "\ng= "); | ||
165 | bignum_print(dh->g); | ||
166 | fprintf(stderr, "\npub= "); | ||
167 | bignum_print(dh->pub_key); | ||
168 | fprintf(stderr, "\n"); | ||
169 | DHparams_print_fp(stderr, dh); | ||
170 | #endif | ||
171 | |||
172 | debug("Wait SSH2_MSG_KEXDH_REPLY."); | ||
173 | |||
174 | packet_read_expect(&payload_len, SSH2_MSG_KEXDH_REPLY); | ||
175 | |||
176 | debug("Got SSH2_MSG_KEXDH_REPLY."); | ||
177 | |||
178 | /* key, cert */ | ||
179 | server_host_key_blob = packet_get_string(&sbloblen); | ||
180 | server_host_key = dsa_key_from_blob(server_host_key_blob, sbloblen); | ||
181 | if (server_host_key == NULL) | ||
182 | fatal("cannot decode server_host_key_blob"); | ||
183 | |||
184 | check_host_key(host, hostaddr, server_host_key, | ||
185 | options.user_hostfile2, options.system_hostfile2); | ||
186 | |||
187 | /* DH paramter f, server public DH key */ | ||
188 | dh_server_pub = BN_new(); | ||
189 | if (dh_server_pub == NULL) | ||
190 | fatal("dh_server_pub == NULL"); | ||
191 | packet_get_bignum2(dh_server_pub, &dlen); | ||
192 | |||
193 | #ifdef DEBUG_KEXDH | ||
194 | fprintf(stderr, "\ndh_server_pub= "); | ||
195 | bignum_print(dh_server_pub); | ||
196 | fprintf(stderr, "\n"); | ||
197 | debug("bits %d", BN_num_bits(dh_server_pub)); | ||
198 | #endif | ||
199 | |||
200 | /* signed H */ | ||
201 | signature = packet_get_string(&slen); | ||
202 | packet_done(); | ||
203 | |||
204 | if (!dh_pub_is_valid(dh, dh_server_pub)) | ||
205 | packet_disconnect("bad server public DH value"); | ||
206 | |||
207 | klen = DH_size(dh); | ||
208 | kbuf = xmalloc(klen); | ||
209 | kout = DH_compute_key(kbuf, dh_server_pub, dh); | ||
210 | #ifdef DEBUG_KEXDH | ||
211 | debug("shared secret: len %d/%d", klen, kout); | ||
212 | fprintf(stderr, "shared secret == "); | ||
213 | for (i = 0; i< kout; i++) | ||
214 | fprintf(stderr, "%02x", (kbuf[i])&0xff); | ||
215 | fprintf(stderr, "\n"); | ||
216 | #endif | ||
217 | shared_secret = BN_new(); | ||
218 | |||
219 | BN_bin2bn(kbuf, kout, shared_secret); | ||
220 | memset(kbuf, 0, klen); | ||
221 | xfree(kbuf); | ||
222 | |||
223 | /* calc and verify H */ | ||
224 | hash = kex_hash( | ||
225 | client_version_string, | ||
226 | server_version_string, | ||
227 | buffer_ptr(client_kexinit), buffer_len(client_kexinit), | ||
228 | buffer_ptr(server_kexinit), buffer_len(server_kexinit), | ||
229 | server_host_key_blob, sbloblen, | ||
230 | dh->pub_key, | ||
231 | dh_server_pub, | ||
232 | shared_secret | ||
233 | ); | ||
234 | xfree(server_host_key_blob); | ||
235 | buffer_free(client_kexinit); | ||
236 | buffer_free(server_kexinit); | ||
237 | xfree(client_kexinit); | ||
238 | xfree(server_kexinit); | ||
239 | #ifdef DEBUG_KEXDH | ||
240 | fprintf(stderr, "hash == "); | ||
241 | for (i = 0; i< 20; i++) | ||
242 | fprintf(stderr, "%02x", (hash[i])&0xff); | ||
243 | fprintf(stderr, "\n"); | ||
244 | #endif | ||
245 | if (dsa_verify(server_host_key, (unsigned char *)signature, slen, hash, 20) != 1) | ||
246 | fatal("dsa_verify failed for server_host_key"); | ||
247 | key_free(server_host_key); | ||
248 | |||
249 | kex_derive_keys(kex, hash, shared_secret); | ||
250 | packet_set_kex(kex); | ||
251 | |||
252 | /* have keys, free DH */ | ||
253 | DH_free(dh); | ||
254 | |||
255 | /* save session id */ | ||
256 | session_id2_len = 20; | ||
257 | session_id2 = xmalloc(session_id2_len); | ||
258 | memcpy(session_id2, hash, session_id2_len); | ||
259 | |||
260 | debug("Wait SSH2_MSG_NEWKEYS."); | ||
261 | packet_read_expect(&payload_len, SSH2_MSG_NEWKEYS); | ||
262 | packet_done(); | ||
263 | debug("GOT SSH2_MSG_NEWKEYS."); | ||
264 | |||
265 | debug("send SSH2_MSG_NEWKEYS."); | ||
266 | packet_start(SSH2_MSG_NEWKEYS); | ||
267 | packet_send(); | ||
268 | packet_write_wait(); | ||
269 | debug("done: send SSH2_MSG_NEWKEYS."); | ||
270 | |||
271 | #ifdef DEBUG_KEXDH | ||
272 | /* send 1st encrypted/maced/compressed message */ | ||
273 | packet_start(SSH2_MSG_IGNORE); | ||
274 | packet_put_cstring("markus"); | ||
275 | packet_send(); | ||
276 | packet_write_wait(); | ||
277 | #endif | ||
278 | debug("done: KEX2."); | ||
279 | } | ||
280 | /* | ||
281 | * Authenticate user | ||
282 | */ | ||
283 | int | ||
284 | ssh2_try_passwd(const char *server_user, const char *host, const char *service) | ||
285 | { | ||
286 | char prompt[80]; | ||
287 | char *password; | ||
288 | |||
289 | snprintf(prompt, sizeof(prompt), "%.30s@%.40s's password: ", | ||
290 | server_user, host); | ||
291 | password = read_passphrase(prompt, 0); | ||
292 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | ||
293 | packet_put_cstring(server_user); | ||
294 | packet_put_cstring(service); | ||
295 | packet_put_cstring("password"); | ||
296 | packet_put_char(0); | ||
297 | packet_put_cstring(password); | ||
298 | memset(password, 0, strlen(password)); | ||
299 | xfree(password); | ||
300 | packet_send(); | ||
301 | packet_write_wait(); | ||
302 | return 1; | ||
303 | } | ||
304 | |||
305 | int | ||
306 | ssh2_try_pubkey(char *filename, | ||
307 | const char *server_user, const char *host, const char *service) | ||
308 | { | ||
309 | Buffer b; | ||
310 | Key *k; | ||
311 | unsigned char *blob, *signature; | ||
312 | int bloblen, slen; | ||
313 | |||
314 | debug("try pubkey: %s", filename); | ||
315 | |||
316 | k = key_new(KEY_DSA); | ||
317 | if (!load_private_key(filename, "", k, NULL)) { | ||
318 | int success = 0; | ||
319 | char *passphrase; | ||
320 | char prompt[300]; | ||
321 | snprintf(prompt, sizeof prompt, | ||
322 | "Enter passphrase for DSA key '%.100s': ", | ||
323 | filename); | ||
324 | passphrase = read_passphrase(prompt, 0); | ||
325 | success = load_private_key(filename, passphrase, k, NULL); | ||
326 | memset(passphrase, 0, strlen(passphrase)); | ||
327 | xfree(passphrase); | ||
328 | if (!success) | ||
329 | return 0; | ||
330 | } | ||
331 | dsa_make_key_blob(k, &blob, &bloblen); | ||
332 | |||
333 | /* data to be signed */ | ||
334 | buffer_init(&b); | ||
335 | buffer_append(&b, session_id2, session_id2_len); | ||
336 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); | ||
337 | buffer_put_cstring(&b, server_user); | ||
338 | buffer_put_cstring(&b, service); | ||
339 | buffer_put_cstring(&b, "publickey"); | ||
340 | buffer_put_char(&b, 1); | ||
341 | buffer_put_cstring(&b, KEX_DSS); | ||
342 | buffer_put_string(&b, blob, bloblen); | ||
343 | xfree(blob); | ||
344 | |||
345 | /* generate signature */ | ||
346 | dsa_sign(k, &signature, &slen, buffer_ptr(&b), buffer_len(&b)); | ||
347 | key_free(k); | ||
348 | #ifdef DEBUG_DSS | ||
349 | buffer_dump(&b); | ||
350 | #endif | ||
351 | /* append signature */ | ||
352 | buffer_put_string(&b, signature, slen); | ||
353 | xfree(signature); | ||
354 | |||
355 | /* skip session id and packet type */ | ||
356 | if (buffer_len(&b) < session_id2_len + 1) | ||
357 | fatal("ssh2_try_pubkey: internal error"); | ||
358 | buffer_consume(&b, session_id2_len + 1); | ||
359 | |||
360 | /* put remaining data from buffer into packet */ | ||
361 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | ||
362 | packet_put_raw(buffer_ptr(&b), buffer_len(&b)); | ||
363 | buffer_free(&b); | ||
364 | |||
365 | /* send */ | ||
366 | packet_send(); | ||
367 | packet_write_wait(); | ||
368 | return 1; | ||
369 | } | ||
370 | |||
371 | void | ||
372 | ssh_userauth2(const char *server_user, char *host) | ||
373 | { | ||
374 | int type; | ||
375 | int plen; | ||
376 | int sent; | ||
377 | unsigned int dlen; | ||
378 | int partial; | ||
379 | int i = 0; | ||
380 | char *auths; | ||
381 | char *service = "ssh-connection"; /* service name */ | ||
382 | |||
383 | debug("send SSH2_MSG_SERVICE_REQUEST"); | ||
384 | packet_start(SSH2_MSG_SERVICE_REQUEST); | ||
385 | packet_put_cstring("ssh-userauth"); | ||
386 | packet_send(); | ||
387 | packet_write_wait(); | ||
388 | |||
389 | type = packet_read(&plen); | ||
390 | if (type != SSH2_MSG_SERVICE_ACCEPT) { | ||
391 | fatal("denied SSH2_MSG_SERVICE_ACCEPT: %d", type); | ||
392 | } | ||
393 | if (packet_remaining() > 0) { | ||
394 | char *reply = packet_get_string(&plen); | ||
395 | debug("service_accept: %s", reply); | ||
396 | xfree(reply); | ||
397 | } else { | ||
398 | /* payload empty for ssh-2.0.13 ?? */ | ||
399 | log("buggy server: service_accept w/o service"); | ||
400 | } | ||
401 | packet_done(); | ||
402 | debug("got SSH2_MSG_SERVICE_ACCEPT"); | ||
403 | |||
404 | /* INITIAL request for auth */ | ||
405 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | ||
406 | packet_put_cstring(server_user); | ||
407 | packet_put_cstring(service); | ||
408 | packet_put_cstring("none"); | ||
409 | packet_send(); | ||
410 | packet_write_wait(); | ||
411 | |||
412 | for (;;) { | ||
413 | sent = 0; | ||
414 | type = packet_read(&plen); | ||
415 | if (type == SSH2_MSG_USERAUTH_SUCCESS) | ||
416 | break; | ||
417 | if (type != SSH2_MSG_USERAUTH_FAILURE) | ||
418 | fatal("access denied: %d", type); | ||
419 | /* SSH2_MSG_USERAUTH_FAILURE means: try again */ | ||
420 | auths = packet_get_string(&dlen); | ||
421 | debug("authentications that can continue: %s", auths); | ||
422 | partial = packet_get_char(); | ||
423 | packet_done(); | ||
424 | if (partial) | ||
425 | debug("partial success"); | ||
426 | if (options.rsa_authentication && | ||
427 | strstr(auths, "publickey") != NULL) { | ||
428 | while (i < options.num_identity_files2) { | ||
429 | sent = ssh2_try_pubkey( | ||
430 | options.identity_files2[i++], | ||
431 | server_user, host, service); | ||
432 | if (sent) | ||
433 | break; | ||
434 | } | ||
435 | } | ||
436 | if (!sent) { | ||
437 | if (options.password_authentication && | ||
438 | !options.batch_mode && | ||
439 | strstr(auths, "password") != NULL) { | ||
440 | sent = ssh2_try_passwd(server_user, host, service); | ||
441 | } | ||
442 | } | ||
443 | if (!sent) | ||
444 | fatal("Permission denied (%s).", auths); | ||
445 | xfree(auths); | ||
446 | } | ||
447 | packet_done(); | ||
448 | debug("ssh-userauth2 successfull"); | ||
449 | } | ||