Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 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. |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 12 | * |
| 13 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| 14 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| 15 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| 16 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 17 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 18 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 19 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 20 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 21 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| 22 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 23 | */ |
| 24 | |
| 25 | #include "includes.h" |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 26 | RCSID("$OpenBSD: sshconnect2.c,v 1.18 2000/09/07 20:27:55 deraadt Exp $"); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 27 | |
| 28 | #include <openssl/bn.h> |
| 29 | #include <openssl/rsa.h> |
| 30 | #include <openssl/dsa.h> |
| 31 | #include <openssl/md5.h> |
| 32 | #include <openssl/dh.h> |
| 33 | #include <openssl/hmac.h> |
| 34 | |
| 35 | #include "ssh.h" |
| 36 | #include "xmalloc.h" |
| 37 | #include "rsa.h" |
| 38 | #include "buffer.h" |
| 39 | #include "packet.h" |
| 40 | #include "cipher.h" |
| 41 | #include "uidswap.h" |
| 42 | #include "compat.h" |
| 43 | #include "readconf.h" |
| 44 | #include "bufaux.h" |
| 45 | #include "ssh2.h" |
| 46 | #include "kex.h" |
| 47 | #include "myproposal.h" |
| 48 | #include "key.h" |
| 49 | #include "dsa.h" |
| 50 | #include "sshconnect.h" |
| 51 | #include "authfile.h" |
Damien Miller | ad833b3 | 2000-08-23 10:46:23 +1000 | [diff] [blame] | 52 | #include "authfd.h" |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 53 | |
| 54 | /* import */ |
| 55 | extern char *client_version_string; |
| 56 | extern char *server_version_string; |
| 57 | extern Options options; |
| 58 | |
| 59 | /* |
| 60 | * SSH2 key exchange |
| 61 | */ |
| 62 | |
| 63 | unsigned char *session_id2 = NULL; |
| 64 | int session_id2_len = 0; |
| 65 | |
| 66 | void |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 67 | ssh_kex_dh(Kex *kex, char *host, struct sockaddr *hostaddr, |
| 68 | Buffer *client_kexinit, Buffer *server_kexinit) |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 69 | { |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 70 | int plen, dlen; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 71 | unsigned int klen, kout; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 72 | char *signature = NULL; |
| 73 | unsigned int slen; |
| 74 | char *server_host_key_blob = NULL; |
| 75 | Key *server_host_key; |
| 76 | unsigned int sbloblen; |
| 77 | DH *dh; |
| 78 | BIGNUM *dh_server_pub = 0; |
| 79 | BIGNUM *shared_secret = 0; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 80 | unsigned char *kbuf; |
| 81 | unsigned char *hash; |
| 82 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 83 | debug("Sending SSH2_MSG_KEXDH_INIT."); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 84 | /* generate and send 'e', client DH public key */ |
| 85 | dh = dh_new_group1(); |
| 86 | packet_start(SSH2_MSG_KEXDH_INIT); |
| 87 | packet_put_bignum2(dh->pub_key); |
| 88 | packet_send(); |
| 89 | packet_write_wait(); |
| 90 | |
| 91 | #ifdef DEBUG_KEXDH |
| 92 | fprintf(stderr, "\np= "); |
| 93 | bignum_print(dh->p); |
| 94 | fprintf(stderr, "\ng= "); |
| 95 | bignum_print(dh->g); |
| 96 | fprintf(stderr, "\npub= "); |
| 97 | bignum_print(dh->pub_key); |
| 98 | fprintf(stderr, "\n"); |
| 99 | DHparams_print_fp(stderr, dh); |
| 100 | #endif |
| 101 | |
| 102 | debug("Wait SSH2_MSG_KEXDH_REPLY."); |
| 103 | |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 104 | packet_read_expect(&plen, SSH2_MSG_KEXDH_REPLY); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 105 | |
| 106 | debug("Got SSH2_MSG_KEXDH_REPLY."); |
| 107 | |
| 108 | /* key, cert */ |
| 109 | server_host_key_blob = packet_get_string(&sbloblen); |
| 110 | server_host_key = dsa_key_from_blob(server_host_key_blob, sbloblen); |
| 111 | if (server_host_key == NULL) |
| 112 | fatal("cannot decode server_host_key_blob"); |
| 113 | |
| 114 | check_host_key(host, hostaddr, server_host_key, |
| 115 | options.user_hostfile2, options.system_hostfile2); |
| 116 | |
| 117 | /* DH paramter f, server public DH key */ |
| 118 | dh_server_pub = BN_new(); |
| 119 | if (dh_server_pub == NULL) |
| 120 | fatal("dh_server_pub == NULL"); |
| 121 | packet_get_bignum2(dh_server_pub, &dlen); |
| 122 | |
| 123 | #ifdef DEBUG_KEXDH |
| 124 | fprintf(stderr, "\ndh_server_pub= "); |
| 125 | bignum_print(dh_server_pub); |
| 126 | fprintf(stderr, "\n"); |
| 127 | debug("bits %d", BN_num_bits(dh_server_pub)); |
| 128 | #endif |
| 129 | |
| 130 | /* signed H */ |
| 131 | signature = packet_get_string(&slen); |
| 132 | packet_done(); |
| 133 | |
| 134 | if (!dh_pub_is_valid(dh, dh_server_pub)) |
| 135 | packet_disconnect("bad server public DH value"); |
| 136 | |
| 137 | klen = DH_size(dh); |
| 138 | kbuf = xmalloc(klen); |
| 139 | kout = DH_compute_key(kbuf, dh_server_pub, dh); |
| 140 | #ifdef DEBUG_KEXDH |
| 141 | debug("shared secret: len %d/%d", klen, kout); |
| 142 | fprintf(stderr, "shared secret == "); |
| 143 | for (i = 0; i< kout; i++) |
| 144 | fprintf(stderr, "%02x", (kbuf[i])&0xff); |
| 145 | fprintf(stderr, "\n"); |
| 146 | #endif |
| 147 | shared_secret = BN_new(); |
| 148 | |
| 149 | BN_bin2bn(kbuf, kout, shared_secret); |
| 150 | memset(kbuf, 0, klen); |
| 151 | xfree(kbuf); |
| 152 | |
| 153 | /* calc and verify H */ |
| 154 | hash = kex_hash( |
| 155 | client_version_string, |
| 156 | server_version_string, |
| 157 | buffer_ptr(client_kexinit), buffer_len(client_kexinit), |
| 158 | buffer_ptr(server_kexinit), buffer_len(server_kexinit), |
| 159 | server_host_key_blob, sbloblen, |
| 160 | dh->pub_key, |
| 161 | dh_server_pub, |
| 162 | shared_secret |
| 163 | ); |
| 164 | xfree(server_host_key_blob); |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 165 | DH_free(dh); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 166 | #ifdef DEBUG_KEXDH |
| 167 | fprintf(stderr, "hash == "); |
| 168 | for (i = 0; i< 20; i++) |
| 169 | fprintf(stderr, "%02x", (hash[i])&0xff); |
| 170 | fprintf(stderr, "\n"); |
| 171 | #endif |
| 172 | if (dsa_verify(server_host_key, (unsigned char *)signature, slen, hash, 20) != 1) |
| 173 | fatal("dsa_verify failed for server_host_key"); |
| 174 | key_free(server_host_key); |
| 175 | |
| 176 | kex_derive_keys(kex, hash, shared_secret); |
| 177 | packet_set_kex(kex); |
| 178 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 179 | /* save session id */ |
| 180 | session_id2_len = 20; |
| 181 | session_id2 = xmalloc(session_id2_len); |
| 182 | memcpy(session_id2, hash, session_id2_len); |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 183 | } |
| 184 | |
| 185 | void |
| 186 | ssh_kex2(char *host, struct sockaddr *hostaddr) |
| 187 | { |
| 188 | int i, plen; |
| 189 | Kex *kex; |
| 190 | Buffer *client_kexinit, *server_kexinit; |
| 191 | char *sprop[PROPOSAL_MAX]; |
| 192 | |
| 193 | if (options.ciphers != NULL) { |
| 194 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = |
| 195 | myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers; |
| 196 | } else if (options.cipher == SSH_CIPHER_3DES) { |
| 197 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = |
| 198 | myproposal[PROPOSAL_ENC_ALGS_STOC] = |
| 199 | (char *) cipher_name(SSH_CIPHER_3DES_CBC); |
| 200 | } else if (options.cipher == SSH_CIPHER_BLOWFISH) { |
| 201 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = |
| 202 | myproposal[PROPOSAL_ENC_ALGS_STOC] = |
| 203 | (char *) cipher_name(SSH_CIPHER_BLOWFISH_CBC); |
| 204 | } |
| 205 | if (options.compression) { |
| 206 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = "zlib"; |
| 207 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib"; |
| 208 | } else { |
| 209 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = "none"; |
| 210 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "none"; |
| 211 | } |
| 212 | |
| 213 | /* buffers with raw kexinit messages */ |
| 214 | server_kexinit = xmalloc(sizeof(*server_kexinit)); |
| 215 | buffer_init(server_kexinit); |
| 216 | client_kexinit = kex_init(myproposal); |
| 217 | |
| 218 | /* algorithm negotiation */ |
| 219 | kex_exchange_kexinit(client_kexinit, server_kexinit, sprop); |
| 220 | kex = kex_choose_conf(myproposal, sprop, 0); |
| 221 | for (i = 0; i < PROPOSAL_MAX; i++) |
| 222 | xfree(sprop[i]); |
| 223 | |
| 224 | /* server authentication and session key agreement */ |
| 225 | ssh_kex_dh(kex, host, hostaddr, client_kexinit, server_kexinit); |
| 226 | |
| 227 | buffer_free(client_kexinit); |
| 228 | buffer_free(server_kexinit); |
| 229 | xfree(client_kexinit); |
| 230 | xfree(server_kexinit); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 231 | |
| 232 | debug("Wait SSH2_MSG_NEWKEYS."); |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 233 | packet_read_expect(&plen, SSH2_MSG_NEWKEYS); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 234 | packet_done(); |
| 235 | debug("GOT SSH2_MSG_NEWKEYS."); |
| 236 | |
| 237 | debug("send SSH2_MSG_NEWKEYS."); |
| 238 | packet_start(SSH2_MSG_NEWKEYS); |
| 239 | packet_send(); |
| 240 | packet_write_wait(); |
| 241 | debug("done: send SSH2_MSG_NEWKEYS."); |
| 242 | |
| 243 | #ifdef DEBUG_KEXDH |
| 244 | /* send 1st encrypted/maced/compressed message */ |
| 245 | packet_start(SSH2_MSG_IGNORE); |
| 246 | packet_put_cstring("markus"); |
| 247 | packet_send(); |
| 248 | packet_write_wait(); |
| 249 | #endif |
| 250 | debug("done: KEX2."); |
| 251 | } |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 252 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 253 | /* |
| 254 | * Authenticate user |
| 255 | */ |
| 256 | int |
| 257 | ssh2_try_passwd(const char *server_user, const char *host, const char *service) |
| 258 | { |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 259 | static int attempt = 0; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 260 | char prompt[80]; |
| 261 | char *password; |
| 262 | |
Damien Miller | d3a1857 | 2000-06-07 19:55:44 +1000 | [diff] [blame] | 263 | if (attempt++ >= options.number_of_password_prompts) |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 264 | return 0; |
| 265 | |
Damien Miller | d3a1857 | 2000-06-07 19:55:44 +1000 | [diff] [blame] | 266 | if(attempt != 1) |
| 267 | error("Permission denied, please try again."); |
| 268 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 269 | snprintf(prompt, sizeof(prompt), "%.30s@%.40s's password: ", |
| 270 | server_user, host); |
| 271 | password = read_passphrase(prompt, 0); |
| 272 | packet_start(SSH2_MSG_USERAUTH_REQUEST); |
| 273 | packet_put_cstring(server_user); |
| 274 | packet_put_cstring(service); |
| 275 | packet_put_cstring("password"); |
| 276 | packet_put_char(0); |
| 277 | packet_put_cstring(password); |
| 278 | memset(password, 0, strlen(password)); |
| 279 | xfree(password); |
| 280 | packet_send(); |
| 281 | packet_write_wait(); |
| 282 | return 1; |
| 283 | } |
| 284 | |
Damien Miller | 994cf14 | 2000-07-21 10:19:44 +1000 | [diff] [blame] | 285 | typedef int sign_fn( |
| 286 | Key *key, |
| 287 | unsigned char **sigp, int *lenp, |
| 288 | unsigned char *data, int datalen); |
| 289 | |
Damien Miller | ad833b3 | 2000-08-23 10:46:23 +1000 | [diff] [blame] | 290 | int |
Damien Miller | 994cf14 | 2000-07-21 10:19:44 +1000 | [diff] [blame] | 291 | ssh2_sign_and_send_pubkey(Key *k, sign_fn *do_sign, |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 292 | const char *server_user, const char *host, const char *service) |
| 293 | { |
| 294 | Buffer b; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 295 | unsigned char *blob, *signature; |
| 296 | int bloblen, slen; |
Damien Miller | 6536c7d | 2000-06-22 21:32:31 +1000 | [diff] [blame] | 297 | int skip = 0; |
Damien Miller | ad833b3 | 2000-08-23 10:46:23 +1000 | [diff] [blame] | 298 | int ret = -1; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 299 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 300 | dsa_make_key_blob(k, &blob, &bloblen); |
| 301 | |
| 302 | /* data to be signed */ |
| 303 | buffer_init(&b); |
Damien Miller | 6536c7d | 2000-06-22 21:32:31 +1000 | [diff] [blame] | 304 | if (datafellows & SSH_COMPAT_SESSIONID_ENCODING) { |
| 305 | buffer_put_string(&b, session_id2, session_id2_len); |
| 306 | skip = buffer_len(&b); |
| 307 | } else { |
| 308 | buffer_append(&b, session_id2, session_id2_len); |
| 309 | skip = session_id2_len; |
| 310 | } |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 311 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); |
| 312 | buffer_put_cstring(&b, server_user); |
Damien Miller | 30c3d42 | 2000-05-09 11:02:59 +1000 | [diff] [blame] | 313 | buffer_put_cstring(&b, |
| 314 | datafellows & SSH_BUG_PUBKEYAUTH ? |
| 315 | "ssh-userauth" : |
| 316 | service); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 317 | buffer_put_cstring(&b, "publickey"); |
| 318 | buffer_put_char(&b, 1); |
| 319 | buffer_put_cstring(&b, KEX_DSS); |
| 320 | buffer_put_string(&b, blob, bloblen); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 321 | |
| 322 | /* generate signature */ |
Damien Miller | ad833b3 | 2000-08-23 10:46:23 +1000 | [diff] [blame] | 323 | ret = do_sign(k, &signature, &slen, buffer_ptr(&b), buffer_len(&b)); |
| 324 | if (ret == -1) { |
| 325 | xfree(blob); |
| 326 | buffer_free(&b); |
| 327 | return 0; |
| 328 | } |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 329 | #ifdef DEBUG_DSS |
| 330 | buffer_dump(&b); |
| 331 | #endif |
Damien Miller | 30c3d42 | 2000-05-09 11:02:59 +1000 | [diff] [blame] | 332 | if (datafellows & SSH_BUG_PUBKEYAUTH) { |
Damien Miller | 30c3d42 | 2000-05-09 11:02:59 +1000 | [diff] [blame] | 333 | buffer_clear(&b); |
| 334 | buffer_append(&b, session_id2, session_id2_len); |
| 335 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); |
| 336 | buffer_put_cstring(&b, server_user); |
| 337 | buffer_put_cstring(&b, service); |
| 338 | buffer_put_cstring(&b, "publickey"); |
| 339 | buffer_put_char(&b, 1); |
| 340 | buffer_put_cstring(&b, KEX_DSS); |
| 341 | buffer_put_string(&b, blob, bloblen); |
| 342 | } |
| 343 | xfree(blob); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 344 | /* append signature */ |
| 345 | buffer_put_string(&b, signature, slen); |
| 346 | xfree(signature); |
| 347 | |
| 348 | /* skip session id and packet type */ |
Damien Miller | 6536c7d | 2000-06-22 21:32:31 +1000 | [diff] [blame] | 349 | if (buffer_len(&b) < skip + 1) |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 350 | fatal("ssh2_try_pubkey: internal error"); |
Damien Miller | 6536c7d | 2000-06-22 21:32:31 +1000 | [diff] [blame] | 351 | buffer_consume(&b, skip + 1); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 352 | |
| 353 | /* put remaining data from buffer into packet */ |
| 354 | packet_start(SSH2_MSG_USERAUTH_REQUEST); |
| 355 | packet_put_raw(buffer_ptr(&b), buffer_len(&b)); |
| 356 | buffer_free(&b); |
| 357 | |
| 358 | /* send */ |
| 359 | packet_send(); |
| 360 | packet_write_wait(); |
Damien Miller | ad833b3 | 2000-08-23 10:46:23 +1000 | [diff] [blame] | 361 | |
| 362 | return 1; |
Damien Miller | 994cf14 | 2000-07-21 10:19:44 +1000 | [diff] [blame] | 363 | } |
| 364 | |
| 365 | int |
| 366 | ssh2_try_pubkey(char *filename, |
| 367 | const char *server_user, const char *host, const char *service) |
| 368 | { |
| 369 | Key *k; |
Damien Miller | ad833b3 | 2000-08-23 10:46:23 +1000 | [diff] [blame] | 370 | int ret = 0; |
Damien Miller | 994cf14 | 2000-07-21 10:19:44 +1000 | [diff] [blame] | 371 | struct stat st; |
| 372 | |
| 373 | if (stat(filename, &st) != 0) { |
| 374 | debug("key does not exist: %s", filename); |
| 375 | return 0; |
| 376 | } |
| 377 | debug("try pubkey: %s", filename); |
| 378 | |
| 379 | k = key_new(KEY_DSA); |
| 380 | if (!load_private_key(filename, "", k, NULL)) { |
| 381 | int success = 0; |
| 382 | char *passphrase; |
| 383 | char prompt[300]; |
| 384 | snprintf(prompt, sizeof prompt, |
| 385 | "Enter passphrase for DSA key '%.100s': ", |
| 386 | filename); |
| 387 | passphrase = read_passphrase(prompt, 0); |
| 388 | success = load_private_key(filename, passphrase, k, NULL); |
| 389 | memset(passphrase, 0, strlen(passphrase)); |
| 390 | xfree(passphrase); |
| 391 | if (!success) { |
| 392 | key_free(k); |
| 393 | return 0; |
| 394 | } |
| 395 | } |
Damien Miller | ad833b3 | 2000-08-23 10:46:23 +1000 | [diff] [blame] | 396 | ret = ssh2_sign_and_send_pubkey(k, dsa_sign, server_user, host, service); |
| 397 | key_free(k); |
| 398 | return ret; |
| 399 | } |
| 400 | |
| 401 | int agent_sign( |
| 402 | Key *key, |
| 403 | unsigned char **sigp, int *lenp, |
| 404 | unsigned char *data, int datalen) |
| 405 | { |
| 406 | int ret = -1; |
| 407 | AuthenticationConnection *ac = ssh_get_authentication_connection(); |
| 408 | if (ac != NULL) { |
| 409 | ret = ssh_agent_sign(ac, key, sigp, lenp, data, datalen); |
| 410 | ssh_close_authentication_connection(ac); |
| 411 | } |
| 412 | return ret; |
| 413 | } |
| 414 | |
| 415 | int |
| 416 | ssh2_try_agent(AuthenticationConnection *ac, |
| 417 | const char *server_user, const char *host, const char *service) |
| 418 | { |
| 419 | static int called = 0; |
| 420 | char *comment; |
| 421 | Key *k; |
| 422 | int ret; |
| 423 | |
| 424 | if (called == 0) { |
| 425 | k = ssh_get_first_identity(ac, &comment, 2); |
| 426 | called ++; |
| 427 | } else { |
| 428 | k = ssh_get_next_identity(ac, &comment, 2); |
| 429 | } |
| 430 | if (k == NULL) |
| 431 | return 0; |
| 432 | debug("trying DSA agent key %s", comment); |
| 433 | xfree(comment); |
| 434 | ret = ssh2_sign_and_send_pubkey(k, agent_sign, server_user, host, service); |
| 435 | key_free(k); |
| 436 | return ret; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 437 | } |
| 438 | |
| 439 | void |
| 440 | ssh_userauth2(const char *server_user, char *host) |
| 441 | { |
Damien Miller | ad833b3 | 2000-08-23 10:46:23 +1000 | [diff] [blame] | 442 | AuthenticationConnection *ac = ssh_get_authentication_connection(); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 443 | int type; |
| 444 | int plen; |
| 445 | int sent; |
| 446 | unsigned int dlen; |
| 447 | int partial; |
| 448 | int i = 0; |
| 449 | char *auths; |
| 450 | char *service = "ssh-connection"; /* service name */ |
| 451 | |
| 452 | debug("send SSH2_MSG_SERVICE_REQUEST"); |
| 453 | packet_start(SSH2_MSG_SERVICE_REQUEST); |
| 454 | packet_put_cstring("ssh-userauth"); |
| 455 | packet_send(); |
| 456 | packet_write_wait(); |
| 457 | |
| 458 | type = packet_read(&plen); |
| 459 | if (type != SSH2_MSG_SERVICE_ACCEPT) { |
| 460 | fatal("denied SSH2_MSG_SERVICE_ACCEPT: %d", type); |
| 461 | } |
| 462 | if (packet_remaining() > 0) { |
| 463 | char *reply = packet_get_string(&plen); |
| 464 | debug("service_accept: %s", reply); |
| 465 | xfree(reply); |
| 466 | } else { |
| 467 | /* payload empty for ssh-2.0.13 ?? */ |
Damien Miller | 6d48871 | 2000-05-08 13:44:52 +1000 | [diff] [blame] | 468 | debug("buggy server: service_accept w/o service"); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 469 | } |
| 470 | packet_done(); |
| 471 | debug("got SSH2_MSG_SERVICE_ACCEPT"); |
| 472 | |
| 473 | /* INITIAL request for auth */ |
| 474 | packet_start(SSH2_MSG_USERAUTH_REQUEST); |
| 475 | packet_put_cstring(server_user); |
| 476 | packet_put_cstring(service); |
| 477 | packet_put_cstring("none"); |
| 478 | packet_send(); |
| 479 | packet_write_wait(); |
| 480 | |
| 481 | for (;;) { |
| 482 | sent = 0; |
| 483 | type = packet_read(&plen); |
| 484 | if (type == SSH2_MSG_USERAUTH_SUCCESS) |
| 485 | break; |
| 486 | if (type != SSH2_MSG_USERAUTH_FAILURE) |
| 487 | fatal("access denied: %d", type); |
| 488 | /* SSH2_MSG_USERAUTH_FAILURE means: try again */ |
| 489 | auths = packet_get_string(&dlen); |
| 490 | debug("authentications that can continue: %s", auths); |
| 491 | partial = packet_get_char(); |
| 492 | packet_done(); |
| 493 | if (partial) |
| 494 | debug("partial success"); |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 495 | if (options.dsa_authentication && |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 496 | strstr(auths, "publickey") != NULL) { |
Damien Miller | ad833b3 | 2000-08-23 10:46:23 +1000 | [diff] [blame] | 497 | if (ac != NULL) |
| 498 | sent = ssh2_try_agent(ac, |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 499 | server_user, host, service); |
Damien Miller | ad833b3 | 2000-08-23 10:46:23 +1000 | [diff] [blame] | 500 | if (!sent) { |
| 501 | while (i < options.num_identity_files2) { |
| 502 | sent = ssh2_try_pubkey( |
| 503 | options.identity_files2[i++], |
| 504 | server_user, host, service); |
| 505 | if (sent) |
| 506 | break; |
| 507 | } |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 508 | } |
| 509 | } |
| 510 | if (!sent) { |
| 511 | if (options.password_authentication && |
| 512 | !options.batch_mode && |
| 513 | strstr(auths, "password") != NULL) { |
| 514 | sent = ssh2_try_passwd(server_user, host, service); |
| 515 | } |
| 516 | } |
| 517 | if (!sent) |
| 518 | fatal("Permission denied (%s).", auths); |
| 519 | xfree(auths); |
| 520 | } |
Damien Miller | ad833b3 | 2000-08-23 10:46:23 +1000 | [diff] [blame] | 521 | if (ac != NULL) |
| 522 | ssh_close_authentication_connection(ac); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 523 | packet_done(); |
| 524 | debug("ssh-userauth2 successfull"); |
| 525 | } |