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" |
Ben Lindstrom | d0fca42 | 2001-03-26 13:44:06 +0000 | [diff] [blame^] | 26 | RCSID("$OpenBSD: sshconnect2.c,v 1.56 2001/03/26 08:07:09 markus Exp $"); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 27 | |
| 28 | #include <openssl/bn.h> |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 29 | #include <openssl/md5.h> |
| 30 | #include <openssl/dh.h> |
| 31 | #include <openssl/hmac.h> |
| 32 | |
| 33 | #include "ssh.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 34 | #include "ssh2.h" |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 35 | #include "xmalloc.h" |
| 36 | #include "rsa.h" |
| 37 | #include "buffer.h" |
| 38 | #include "packet.h" |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 39 | #include "uidswap.h" |
| 40 | #include "compat.h" |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 41 | #include "bufaux.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 42 | #include "cipher.h" |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 43 | #include "kex.h" |
| 44 | #include "myproposal.h" |
| 45 | #include "key.h" |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 46 | #include "sshconnect.h" |
| 47 | #include "authfile.h" |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 48 | #include "cli.h" |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 49 | #include "dispatch.h" |
Damien Miller | ad833b3 | 2000-08-23 10:46:23 +1000 | [diff] [blame] | 50 | #include "authfd.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 51 | #include "log.h" |
| 52 | #include "readconf.h" |
| 53 | #include "readpass.h" |
Ben Lindstrom | b9be60a | 2001-03-11 01:49:19 +0000 | [diff] [blame] | 54 | #include "match.h" |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 55 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 56 | void ssh_dh1_client(Kex *, char *, struct sockaddr *, Buffer *, Buffer *); |
| 57 | void ssh_dhgex_client(Kex *, char *, struct sockaddr *, Buffer *, Buffer *); |
| 58 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 59 | /* import */ |
| 60 | extern char *client_version_string; |
| 61 | extern char *server_version_string; |
| 62 | extern Options options; |
| 63 | |
| 64 | /* |
| 65 | * SSH2 key exchange |
| 66 | */ |
| 67 | |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 68 | u_char *session_id2 = NULL; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 69 | int session_id2_len = 0; |
| 70 | |
| 71 | void |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 72 | ssh_kex2(char *host, struct sockaddr *hostaddr) |
| 73 | { |
| 74 | int i, plen; |
| 75 | Kex *kex; |
| 76 | Buffer *client_kexinit, *server_kexinit; |
| 77 | char *sprop[PROPOSAL_MAX]; |
| 78 | |
Damien Miller | e39cacc | 2000-11-29 12:18:44 +1100 | [diff] [blame] | 79 | if (options.ciphers == (char *)-1) { |
| 80 | log("No valid ciphers for protocol version 2 given, using defaults."); |
| 81 | options.ciphers = NULL; |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 82 | } |
| 83 | if (options.ciphers != NULL) { |
| 84 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = |
| 85 | myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers; |
| 86 | } |
| 87 | if (options.compression) { |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 88 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 89 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib"; |
| 90 | } else { |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 91 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 92 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "none"; |
| 93 | } |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 94 | if (options.macs != NULL) { |
| 95 | myproposal[PROPOSAL_MAC_ALGS_CTOS] = |
| 96 | myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs; |
| 97 | } |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 98 | |
Ben Lindstrom | c8530c7 | 2001-03-24 00:35:19 +0000 | [diff] [blame] | 99 | myproposal[PROPOSAL_ENC_ALGS_STOC] = |
| 100 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]); |
| 101 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 102 | /* buffers with raw kexinit messages */ |
| 103 | server_kexinit = xmalloc(sizeof(*server_kexinit)); |
| 104 | buffer_init(server_kexinit); |
| 105 | client_kexinit = kex_init(myproposal); |
| 106 | |
| 107 | /* algorithm negotiation */ |
| 108 | kex_exchange_kexinit(client_kexinit, server_kexinit, sprop); |
| 109 | kex = kex_choose_conf(myproposal, sprop, 0); |
| 110 | for (i = 0; i < PROPOSAL_MAX; i++) |
| 111 | xfree(sprop[i]); |
| 112 | |
| 113 | /* server authentication and session key agreement */ |
| 114 | switch(kex->kex_type) { |
| 115 | case DH_GRP1_SHA1: |
| 116 | ssh_dh1_client(kex, host, hostaddr, |
| 117 | client_kexinit, server_kexinit); |
| 118 | break; |
| 119 | case DH_GEX_SHA1: |
| 120 | ssh_dhgex_client(kex, host, hostaddr, client_kexinit, |
| 121 | server_kexinit); |
| 122 | break; |
| 123 | default: |
| 124 | fatal("Unsupported key exchange %d", kex->kex_type); |
| 125 | } |
| 126 | |
| 127 | buffer_free(client_kexinit); |
| 128 | buffer_free(server_kexinit); |
| 129 | xfree(client_kexinit); |
| 130 | xfree(server_kexinit); |
| 131 | |
| 132 | debug("Wait SSH2_MSG_NEWKEYS."); |
| 133 | packet_read_expect(&plen, SSH2_MSG_NEWKEYS); |
| 134 | packet_done(); |
| 135 | debug("GOT SSH2_MSG_NEWKEYS."); |
| 136 | |
| 137 | debug("send SSH2_MSG_NEWKEYS."); |
| 138 | packet_start(SSH2_MSG_NEWKEYS); |
| 139 | packet_send(); |
| 140 | packet_write_wait(); |
| 141 | debug("done: send SSH2_MSG_NEWKEYS."); |
| 142 | |
| 143 | #ifdef DEBUG_KEXDH |
| 144 | /* send 1st encrypted/maced/compressed message */ |
| 145 | packet_start(SSH2_MSG_IGNORE); |
| 146 | packet_put_cstring("markus"); |
| 147 | packet_send(); |
| 148 | packet_write_wait(); |
| 149 | #endif |
| 150 | debug("done: KEX2."); |
| 151 | } |
| 152 | |
| 153 | /* diffie-hellman-group1-sha1 */ |
| 154 | |
| 155 | void |
Kevin Steves | ef4eea9 | 2001-02-05 12:42:17 +0000 | [diff] [blame] | 156 | ssh_dh1_client(Kex *kex, char *host, struct sockaddr *hostaddr, |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 157 | Buffer *client_kexinit, Buffer *server_kexinit) |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 158 | { |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 159 | #ifdef DEBUG_KEXDH |
| 160 | int i; |
| 161 | #endif |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 162 | int plen, dlen; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 163 | u_int klen, kout; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 164 | char *signature = NULL; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 165 | u_int slen; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 166 | char *server_host_key_blob = NULL; |
| 167 | Key *server_host_key; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 168 | u_int sbloblen; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 169 | DH *dh; |
| 170 | BIGNUM *dh_server_pub = 0; |
| 171 | BIGNUM *shared_secret = 0; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 172 | u_char *kbuf; |
| 173 | u_char *hash; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 174 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 175 | debug("Sending SSH2_MSG_KEXDH_INIT."); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 176 | /* generate and send 'e', client DH public key */ |
| 177 | dh = dh_new_group1(); |
Ben Lindstrom | 4c4f05e | 2001-03-06 01:09:20 +0000 | [diff] [blame] | 178 | dh_gen_key(dh, kex->we_need * 8); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 179 | packet_start(SSH2_MSG_KEXDH_INIT); |
| 180 | packet_put_bignum2(dh->pub_key); |
| 181 | packet_send(); |
| 182 | packet_write_wait(); |
| 183 | |
| 184 | #ifdef DEBUG_KEXDH |
| 185 | fprintf(stderr, "\np= "); |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 186 | BN_print_fp(stderr, dh->p); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 187 | fprintf(stderr, "\ng= "); |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 188 | BN_print_fp(stderr, dh->g); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 189 | fprintf(stderr, "\npub= "); |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 190 | BN_print_fp(stderr, dh->pub_key); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 191 | fprintf(stderr, "\n"); |
| 192 | DHparams_print_fp(stderr, dh); |
| 193 | #endif |
| 194 | |
| 195 | debug("Wait SSH2_MSG_KEXDH_REPLY."); |
| 196 | |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 197 | packet_read_expect(&plen, SSH2_MSG_KEXDH_REPLY); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 198 | |
| 199 | debug("Got SSH2_MSG_KEXDH_REPLY."); |
| 200 | |
| 201 | /* key, cert */ |
| 202 | server_host_key_blob = packet_get_string(&sbloblen); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 203 | server_host_key = key_from_blob(server_host_key_blob, sbloblen); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 204 | if (server_host_key == NULL) |
| 205 | fatal("cannot decode server_host_key_blob"); |
| 206 | |
| 207 | check_host_key(host, hostaddr, server_host_key, |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 208 | options.user_hostfile2, options.system_hostfile2); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 209 | |
| 210 | /* DH paramter f, server public DH key */ |
| 211 | dh_server_pub = BN_new(); |
| 212 | if (dh_server_pub == NULL) |
| 213 | fatal("dh_server_pub == NULL"); |
| 214 | packet_get_bignum2(dh_server_pub, &dlen); |
| 215 | |
| 216 | #ifdef DEBUG_KEXDH |
| 217 | fprintf(stderr, "\ndh_server_pub= "); |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 218 | BN_print_fp(stderr, dh_server_pub); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 219 | fprintf(stderr, "\n"); |
| 220 | debug("bits %d", BN_num_bits(dh_server_pub)); |
| 221 | #endif |
| 222 | |
| 223 | /* signed H */ |
| 224 | signature = packet_get_string(&slen); |
| 225 | packet_done(); |
| 226 | |
| 227 | if (!dh_pub_is_valid(dh, dh_server_pub)) |
| 228 | packet_disconnect("bad server public DH value"); |
| 229 | |
| 230 | klen = DH_size(dh); |
| 231 | kbuf = xmalloc(klen); |
| 232 | kout = DH_compute_key(kbuf, dh_server_pub, dh); |
| 233 | #ifdef DEBUG_KEXDH |
| 234 | debug("shared secret: len %d/%d", klen, kout); |
| 235 | fprintf(stderr, "shared secret == "); |
| 236 | for (i = 0; i< kout; i++) |
| 237 | fprintf(stderr, "%02x", (kbuf[i])&0xff); |
| 238 | fprintf(stderr, "\n"); |
| 239 | #endif |
| 240 | shared_secret = BN_new(); |
| 241 | |
| 242 | BN_bin2bn(kbuf, kout, shared_secret); |
| 243 | memset(kbuf, 0, klen); |
| 244 | xfree(kbuf); |
| 245 | |
| 246 | /* calc and verify H */ |
| 247 | hash = kex_hash( |
| 248 | client_version_string, |
| 249 | server_version_string, |
| 250 | buffer_ptr(client_kexinit), buffer_len(client_kexinit), |
| 251 | buffer_ptr(server_kexinit), buffer_len(server_kexinit), |
| 252 | server_host_key_blob, sbloblen, |
| 253 | dh->pub_key, |
| 254 | dh_server_pub, |
| 255 | shared_secret |
| 256 | ); |
| 257 | xfree(server_host_key_blob); |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 258 | DH_free(dh); |
Ben Lindstrom | b1985f7 | 2001-01-23 00:19:15 +0000 | [diff] [blame] | 259 | BN_free(dh_server_pub); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 260 | #ifdef DEBUG_KEXDH |
| 261 | fprintf(stderr, "hash == "); |
| 262 | for (i = 0; i< 20; i++) |
| 263 | fprintf(stderr, "%02x", (hash[i])&0xff); |
| 264 | fprintf(stderr, "\n"); |
| 265 | #endif |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 266 | if (key_verify(server_host_key, (u_char *)signature, slen, hash, 20) != 1) |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 267 | fatal("key_verify failed for server_host_key"); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 268 | key_free(server_host_key); |
Ben Lindstrom | b1985f7 | 2001-01-23 00:19:15 +0000 | [diff] [blame] | 269 | xfree(signature); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 270 | |
| 271 | kex_derive_keys(kex, hash, shared_secret); |
Ben Lindstrom | b1985f7 | 2001-01-23 00:19:15 +0000 | [diff] [blame] | 272 | BN_clear_free(shared_secret); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 273 | packet_set_kex(kex); |
| 274 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 275 | /* save session id */ |
| 276 | session_id2_len = 20; |
| 277 | session_id2 = xmalloc(session_id2_len); |
| 278 | memcpy(session_id2, hash, session_id2_len); |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 279 | } |
| 280 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 281 | /* diffie-hellman-group-exchange-sha1 */ |
| 282 | |
| 283 | /* |
| 284 | * Estimates the group order for a Diffie-Hellman group that has an |
| 285 | * attack complexity approximately the same as O(2**bits). Estimate |
| 286 | * with: O(exp(1.9223 * (ln q)^(1/3) (ln ln q)^(2/3))) |
| 287 | */ |
| 288 | |
| 289 | int |
| 290 | dh_estimate(int bits) |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 291 | { |
Kevin Steves | ef4eea9 | 2001-02-05 12:42:17 +0000 | [diff] [blame] | 292 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 293 | if (bits < 64) |
| 294 | return (512); /* O(2**63) */ |
| 295 | if (bits < 128) |
| 296 | return (1024); /* O(2**86) */ |
| 297 | if (bits < 192) |
| 298 | return (2048); /* O(2**116) */ |
| 299 | return (4096); /* O(2**156) */ |
| 300 | } |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 301 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 302 | void |
| 303 | ssh_dhgex_client(Kex *kex, char *host, struct sockaddr *hostaddr, |
| 304 | Buffer *client_kexinit, Buffer *server_kexinit) |
| 305 | { |
| 306 | #ifdef DEBUG_KEXDH |
| 307 | int i; |
| 308 | #endif |
| 309 | int plen, dlen; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 310 | u_int klen, kout; |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 311 | char *signature = NULL; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 312 | u_int slen, nbits; |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 313 | char *server_host_key_blob = NULL; |
| 314 | Key *server_host_key; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 315 | u_int sbloblen; |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 316 | DH *dh; |
| 317 | BIGNUM *dh_server_pub = 0; |
| 318 | BIGNUM *shared_secret = 0; |
| 319 | BIGNUM *p = 0, *g = 0; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 320 | u_char *kbuf; |
| 321 | u_char *hash; |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 322 | |
Ben Lindstrom | 4c4f05e | 2001-03-06 01:09:20 +0000 | [diff] [blame] | 323 | nbits = dh_estimate(kex->we_need * 8); |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 324 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 325 | debug("Sending SSH2_MSG_KEX_DH_GEX_REQUEST."); |
| 326 | packet_start(SSH2_MSG_KEX_DH_GEX_REQUEST); |
| 327 | packet_put_int(nbits); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 328 | packet_send(); |
| 329 | packet_write_wait(); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 330 | |
| 331 | #ifdef DEBUG_KEXDH |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 332 | fprintf(stderr, "\nnbits = %d", nbits); |
| 333 | #endif |
| 334 | |
| 335 | debug("Wait SSH2_MSG_KEX_DH_GEX_GROUP."); |
| 336 | |
| 337 | packet_read_expect(&plen, SSH2_MSG_KEX_DH_GEX_GROUP); |
| 338 | |
| 339 | debug("Got SSH2_MSG_KEX_DH_GEX_GROUP."); |
| 340 | |
| 341 | if ((p = BN_new()) == NULL) |
| 342 | fatal("BN_new"); |
| 343 | packet_get_bignum2(p, &dlen); |
| 344 | if ((g = BN_new()) == NULL) |
| 345 | fatal("BN_new"); |
| 346 | packet_get_bignum2(g, &dlen); |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 347 | dh = dh_new_group(g, p); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 348 | |
Ben Lindstrom | 4c4f05e | 2001-03-06 01:09:20 +0000 | [diff] [blame] | 349 | dh_gen_key(dh, kex->we_need * 8); |
Kevin Steves | 6b87586 | 2000-12-15 23:31:01 +0000 | [diff] [blame] | 350 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 351 | #ifdef DEBUG_KEXDH |
| 352 | fprintf(stderr, "\np= "); |
| 353 | BN_print_fp(stderr, dh->p); |
| 354 | fprintf(stderr, "\ng= "); |
| 355 | BN_print_fp(stderr, dh->g); |
| 356 | fprintf(stderr, "\npub= "); |
| 357 | BN_print_fp(stderr, dh->pub_key); |
| 358 | fprintf(stderr, "\n"); |
| 359 | DHparams_print_fp(stderr, dh); |
| 360 | #endif |
| 361 | |
| 362 | debug("Sending SSH2_MSG_KEX_DH_GEX_INIT."); |
| 363 | /* generate and send 'e', client DH public key */ |
| 364 | packet_start(SSH2_MSG_KEX_DH_GEX_INIT); |
| 365 | packet_put_bignum2(dh->pub_key); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 366 | packet_send(); |
| 367 | packet_write_wait(); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 368 | |
| 369 | debug("Wait SSH2_MSG_KEX_DH_GEX_REPLY."); |
| 370 | |
| 371 | packet_read_expect(&plen, SSH2_MSG_KEX_DH_GEX_REPLY); |
| 372 | |
| 373 | debug("Got SSH2_MSG_KEXDH_REPLY."); |
| 374 | |
| 375 | /* key, cert */ |
| 376 | server_host_key_blob = packet_get_string(&sbloblen); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 377 | server_host_key = key_from_blob(server_host_key_blob, sbloblen); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 378 | if (server_host_key == NULL) |
| 379 | fatal("cannot decode server_host_key_blob"); |
| 380 | |
| 381 | check_host_key(host, hostaddr, server_host_key, |
| 382 | options.user_hostfile2, options.system_hostfile2); |
| 383 | |
| 384 | /* DH paramter f, server public DH key */ |
| 385 | dh_server_pub = BN_new(); |
| 386 | if (dh_server_pub == NULL) |
| 387 | fatal("dh_server_pub == NULL"); |
| 388 | packet_get_bignum2(dh_server_pub, &dlen); |
| 389 | |
| 390 | #ifdef DEBUG_KEXDH |
| 391 | fprintf(stderr, "\ndh_server_pub= "); |
| 392 | BN_print_fp(stderr, dh_server_pub); |
| 393 | fprintf(stderr, "\n"); |
| 394 | debug("bits %d", BN_num_bits(dh_server_pub)); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 395 | #endif |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 396 | |
| 397 | /* signed H */ |
| 398 | signature = packet_get_string(&slen); |
| 399 | packet_done(); |
| 400 | |
| 401 | if (!dh_pub_is_valid(dh, dh_server_pub)) |
| 402 | packet_disconnect("bad server public DH value"); |
| 403 | |
| 404 | klen = DH_size(dh); |
| 405 | kbuf = xmalloc(klen); |
| 406 | kout = DH_compute_key(kbuf, dh_server_pub, dh); |
| 407 | #ifdef DEBUG_KEXDH |
| 408 | debug("shared secret: len %d/%d", klen, kout); |
| 409 | fprintf(stderr, "shared secret == "); |
| 410 | for (i = 0; i< kout; i++) |
| 411 | fprintf(stderr, "%02x", (kbuf[i])&0xff); |
| 412 | fprintf(stderr, "\n"); |
| 413 | #endif |
| 414 | shared_secret = BN_new(); |
| 415 | |
| 416 | BN_bin2bn(kbuf, kout, shared_secret); |
| 417 | memset(kbuf, 0, klen); |
| 418 | xfree(kbuf); |
| 419 | |
| 420 | /* calc and verify H */ |
| 421 | hash = kex_hash_gex( |
| 422 | client_version_string, |
| 423 | server_version_string, |
| 424 | buffer_ptr(client_kexinit), buffer_len(client_kexinit), |
| 425 | buffer_ptr(server_kexinit), buffer_len(server_kexinit), |
| 426 | server_host_key_blob, sbloblen, |
Kevin Steves | ef4eea9 | 2001-02-05 12:42:17 +0000 | [diff] [blame] | 427 | nbits, dh->p, dh->g, |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 428 | dh->pub_key, |
| 429 | dh_server_pub, |
| 430 | shared_secret |
| 431 | ); |
| 432 | xfree(server_host_key_blob); |
| 433 | DH_free(dh); |
Ben Lindstrom | b1985f7 | 2001-01-23 00:19:15 +0000 | [diff] [blame] | 434 | BN_free(dh_server_pub); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 435 | #ifdef DEBUG_KEXDH |
| 436 | fprintf(stderr, "hash == "); |
| 437 | for (i = 0; i< 20; i++) |
| 438 | fprintf(stderr, "%02x", (hash[i])&0xff); |
| 439 | fprintf(stderr, "\n"); |
| 440 | #endif |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 441 | if (key_verify(server_host_key, (u_char *)signature, slen, hash, 20) != 1) |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 442 | fatal("key_verify failed for server_host_key"); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 443 | key_free(server_host_key); |
Ben Lindstrom | b1985f7 | 2001-01-23 00:19:15 +0000 | [diff] [blame] | 444 | xfree(signature); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 445 | |
| 446 | kex_derive_keys(kex, hash, shared_secret); |
Ben Lindstrom | b1985f7 | 2001-01-23 00:19:15 +0000 | [diff] [blame] | 447 | BN_clear_free(shared_secret); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 448 | packet_set_kex(kex); |
| 449 | |
| 450 | /* save session id */ |
| 451 | session_id2_len = 20; |
| 452 | session_id2 = xmalloc(session_id2_len); |
| 453 | memcpy(session_id2, hash, session_id2_len); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 454 | } |
Damien Miller | b1715dc | 2000-05-30 13:44:51 +1000 | [diff] [blame] | 455 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 456 | /* |
| 457 | * Authenticate user |
| 458 | */ |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 459 | |
| 460 | typedef struct Authctxt Authctxt; |
| 461 | typedef struct Authmethod Authmethod; |
| 462 | |
| 463 | typedef int sign_cb_fn( |
| 464 | Authctxt *authctxt, Key *key, |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 465 | u_char **sigp, int *lenp, u_char *data, int datalen); |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 466 | |
| 467 | struct Authctxt { |
| 468 | const char *server_user; |
| 469 | const char *host; |
| 470 | const char *service; |
| 471 | AuthenticationConnection *agent; |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 472 | Authmethod *method; |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 473 | int success; |
Ben Lindstrom | 266dfdf | 2001-03-09 00:12:22 +0000 | [diff] [blame] | 474 | char *authlist; |
| 475 | Key *last_key; |
| 476 | sign_cb_fn *last_key_sign; |
| 477 | int last_key_hint; |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 478 | }; |
| 479 | struct Authmethod { |
| 480 | char *name; /* string to compare against server's list */ |
| 481 | int (*userauth)(Authctxt *authctxt); |
| 482 | int *enabled; /* flag in option struct that enables method */ |
| 483 | int *batch_flag; /* flag in option struct that disables method */ |
| 484 | }; |
| 485 | |
| 486 | void input_userauth_success(int type, int plen, void *ctxt); |
| 487 | void input_userauth_failure(int type, int plen, void *ctxt); |
Ben Lindstrom | d26dcf3 | 2001-01-06 15:18:16 +0000 | [diff] [blame] | 488 | void input_userauth_banner(int type, int plen, void *ctxt); |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 489 | void input_userauth_error(int type, int plen, void *ctxt); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 490 | void input_userauth_info_req(int type, int plen, void *ctxt); |
Ben Lindstrom | 266dfdf | 2001-03-09 00:12:22 +0000 | [diff] [blame] | 491 | void input_userauth_pk_ok(int type, int plen, void *ctxt); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 492 | |
| 493 | int userauth_none(Authctxt *authctxt); |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 494 | int userauth_pubkey(Authctxt *authctxt); |
| 495 | int userauth_passwd(Authctxt *authctxt); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 496 | int userauth_kbdint(Authctxt *authctxt); |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 497 | |
Ben Lindstrom | 266dfdf | 2001-03-09 00:12:22 +0000 | [diff] [blame] | 498 | void userauth(Authctxt *authctxt, char *authlist); |
| 499 | |
| 500 | int |
| 501 | sign_and_send_pubkey(Authctxt *authctxt, Key *k, |
| 502 | sign_cb_fn *sign_callback); |
| 503 | void clear_auth_state(Authctxt *authctxt); |
| 504 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 505 | Authmethod *authmethod_get(char *authlist); |
| 506 | Authmethod *authmethod_lookup(const char *name); |
Ben Lindstrom | b9be60a | 2001-03-11 01:49:19 +0000 | [diff] [blame] | 507 | char *authmethods_get(void); |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 508 | |
| 509 | Authmethod authmethods[] = { |
| 510 | {"publickey", |
| 511 | userauth_pubkey, |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 512 | &options.pubkey_authentication, |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 513 | NULL}, |
| 514 | {"password", |
| 515 | userauth_passwd, |
| 516 | &options.password_authentication, |
| 517 | &options.batch_mode}, |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 518 | {"keyboard-interactive", |
| 519 | userauth_kbdint, |
| 520 | &options.kbd_interactive_authentication, |
| 521 | &options.batch_mode}, |
| 522 | {"none", |
| 523 | userauth_none, |
| 524 | NULL, |
| 525 | NULL}, |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 526 | {NULL, NULL, NULL, NULL} |
| 527 | }; |
| 528 | |
| 529 | void |
| 530 | ssh_userauth2(const char *server_user, char *host) |
| 531 | { |
| 532 | Authctxt authctxt; |
| 533 | int type; |
| 534 | int plen; |
| 535 | |
Ben Lindstrom | 95fb2dd | 2001-01-23 03:12:10 +0000 | [diff] [blame] | 536 | if (options.challenge_reponse_authentication) |
| 537 | options.kbd_interactive_authentication = 1; |
| 538 | |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 539 | debug("send SSH2_MSG_SERVICE_REQUEST"); |
| 540 | packet_start(SSH2_MSG_SERVICE_REQUEST); |
| 541 | packet_put_cstring("ssh-userauth"); |
| 542 | packet_send(); |
| 543 | packet_write_wait(); |
| 544 | type = packet_read(&plen); |
| 545 | if (type != SSH2_MSG_SERVICE_ACCEPT) { |
| 546 | fatal("denied SSH2_MSG_SERVICE_ACCEPT: %d", type); |
| 547 | } |
| 548 | if (packet_remaining() > 0) { |
| 549 | char *reply = packet_get_string(&plen); |
| 550 | debug("service_accept: %s", reply); |
| 551 | xfree(reply); |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 552 | } else { |
| 553 | debug("buggy server: service_accept w/o service"); |
| 554 | } |
| 555 | packet_done(); |
| 556 | debug("got SSH2_MSG_SERVICE_ACCEPT"); |
| 557 | |
Ben Lindstrom | b9be60a | 2001-03-11 01:49:19 +0000 | [diff] [blame] | 558 | if (options.preferred_authentications == NULL) |
| 559 | options.preferred_authentications = authmethods_get(); |
| 560 | |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 561 | /* setup authentication context */ |
| 562 | authctxt.agent = ssh_get_authentication_connection(); |
| 563 | authctxt.server_user = server_user; |
| 564 | authctxt.host = host; |
| 565 | authctxt.service = "ssh-connection"; /* service name */ |
| 566 | authctxt.success = 0; |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 567 | authctxt.method = authmethod_lookup("none"); |
Ben Lindstrom | 266dfdf | 2001-03-09 00:12:22 +0000 | [diff] [blame] | 568 | authctxt.authlist = NULL; |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 569 | if (authctxt.method == NULL) |
| 570 | fatal("ssh_userauth2: internal error: cannot send userauth none request"); |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 571 | |
| 572 | /* initial userauth request */ |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 573 | userauth_none(&authctxt); |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 574 | |
| 575 | dispatch_init(&input_userauth_error); |
| 576 | dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success); |
| 577 | dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure); |
Ben Lindstrom | d26dcf3 | 2001-01-06 15:18:16 +0000 | [diff] [blame] | 578 | dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner); |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 579 | dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */ |
| 580 | |
| 581 | if (authctxt.agent != NULL) |
| 582 | ssh_close_authentication_connection(authctxt.agent); |
| 583 | |
Ben Lindstrom | 4dccfa5 | 2000-12-28 16:40:05 +0000 | [diff] [blame] | 584 | debug("ssh-userauth2 successful: method %s", authctxt.method->name); |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 585 | } |
| 586 | void |
Ben Lindstrom | 266dfdf | 2001-03-09 00:12:22 +0000 | [diff] [blame] | 587 | userauth(Authctxt *authctxt, char *authlist) |
| 588 | { |
| 589 | if (authlist == NULL) { |
| 590 | authlist = authctxt->authlist; |
| 591 | } else { |
| 592 | if (authctxt->authlist) |
| 593 | xfree(authctxt->authlist); |
| 594 | authctxt->authlist = authlist; |
| 595 | } |
| 596 | for (;;) { |
| 597 | Authmethod *method = authmethod_get(authlist); |
| 598 | if (method == NULL) |
| 599 | fatal("Permission denied (%s).", authlist); |
| 600 | authctxt->method = method; |
| 601 | if (method->userauth(authctxt) != 0) { |
| 602 | debug2("we sent a %s packet, wait for reply", method->name); |
| 603 | break; |
| 604 | } else { |
| 605 | debug2("we did not send a packet, disable method"); |
| 606 | method->enabled = NULL; |
| 607 | } |
| 608 | } |
| 609 | } |
| 610 | void |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 611 | input_userauth_error(int type, int plen, void *ctxt) |
| 612 | { |
Ben Lindstrom | d26dcf3 | 2001-01-06 15:18:16 +0000 | [diff] [blame] | 613 | fatal("input_userauth_error: bad message during authentication: " |
| 614 | "type %d", type); |
| 615 | } |
| 616 | void |
| 617 | input_userauth_banner(int type, int plen, void *ctxt) |
| 618 | { |
| 619 | char *msg, *lang; |
| 620 | debug3("input_userauth_banner"); |
| 621 | msg = packet_get_string(NULL); |
| 622 | lang = packet_get_string(NULL); |
| 623 | fprintf(stderr, "%s", msg); |
| 624 | xfree(msg); |
| 625 | xfree(lang); |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 626 | } |
| 627 | void |
| 628 | input_userauth_success(int type, int plen, void *ctxt) |
| 629 | { |
| 630 | Authctxt *authctxt = ctxt; |
| 631 | if (authctxt == NULL) |
| 632 | fatal("input_userauth_success: no authentication context"); |
Ben Lindstrom | 266dfdf | 2001-03-09 00:12:22 +0000 | [diff] [blame] | 633 | if (authctxt->authlist) |
| 634 | xfree(authctxt->authlist); |
| 635 | clear_auth_state(authctxt); |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 636 | authctxt->success = 1; /* break out */ |
| 637 | } |
| 638 | void |
| 639 | input_userauth_failure(int type, int plen, void *ctxt) |
| 640 | { |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 641 | Authctxt *authctxt = ctxt; |
| 642 | char *authlist = NULL; |
| 643 | int partial; |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 644 | |
| 645 | if (authctxt == NULL) |
| 646 | fatal("input_userauth_failure: no authentication context"); |
| 647 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 648 | authlist = packet_get_string(NULL); |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 649 | partial = packet_get_char(); |
| 650 | packet_done(); |
| 651 | |
| 652 | if (partial != 0) |
Ben Lindstrom | 03df5bd | 2001-02-10 22:16:41 +0000 | [diff] [blame] | 653 | log("Authenticated with partial success."); |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 654 | debug("authentications that can continue: %s", authlist); |
| 655 | |
Ben Lindstrom | 266dfdf | 2001-03-09 00:12:22 +0000 | [diff] [blame] | 656 | clear_auth_state(authctxt); |
| 657 | userauth(authctxt, authlist); |
| 658 | } |
| 659 | void |
| 660 | input_userauth_pk_ok(int type, int plen, void *ctxt) |
| 661 | { |
| 662 | Authctxt *authctxt = ctxt; |
| 663 | Key *key = NULL; |
| 664 | Buffer b; |
| 665 | int alen, blen, pktype, sent = 0; |
Ben Lindstrom | cfccef9 | 2001-03-13 04:57:58 +0000 | [diff] [blame] | 666 | char *pkalg, *pkblob, *fp; |
Ben Lindstrom | 266dfdf | 2001-03-09 00:12:22 +0000 | [diff] [blame] | 667 | |
| 668 | if (authctxt == NULL) |
| 669 | fatal("input_userauth_pk_ok: no authentication context"); |
| 670 | if (datafellows & SSH_BUG_PKOK) { |
| 671 | /* this is similar to SSH_BUG_PKAUTH */ |
| 672 | debug2("input_userauth_pk_ok: SSH_BUG_PKOK"); |
| 673 | pkblob = packet_get_string(&blen); |
| 674 | buffer_init(&b); |
| 675 | buffer_append(&b, pkblob, blen); |
| 676 | pkalg = buffer_get_string(&b, &alen); |
| 677 | buffer_free(&b); |
| 678 | } else { |
| 679 | pkalg = packet_get_string(&alen); |
| 680 | pkblob = packet_get_string(&blen); |
Kevin Steves | ef4eea9 | 2001-02-05 12:42:17 +0000 | [diff] [blame] | 681 | } |
Ben Lindstrom | 266dfdf | 2001-03-09 00:12:22 +0000 | [diff] [blame] | 682 | packet_done(); |
| 683 | |
| 684 | debug("input_userauth_pk_ok: pkalg %s blen %d lastkey %p hint %d", |
| 685 | pkalg, blen, authctxt->last_key, authctxt->last_key_hint); |
| 686 | |
| 687 | do { |
| 688 | if (authctxt->last_key == NULL || |
| 689 | authctxt->last_key_sign == NULL) { |
| 690 | debug("no last key or no sign cb"); |
| 691 | break; |
| 692 | } |
Ben Lindstrom | 266dfdf | 2001-03-09 00:12:22 +0000 | [diff] [blame] | 693 | if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) { |
| 694 | debug("unknown pkalg %s", pkalg); |
| 695 | break; |
| 696 | } |
| 697 | if ((key = key_from_blob(pkblob, blen)) == NULL) { |
| 698 | debug("no key from blob. pkalg %s", pkalg); |
| 699 | break; |
| 700 | } |
Ben Lindstrom | cfccef9 | 2001-03-13 04:57:58 +0000 | [diff] [blame] | 701 | fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX); |
| 702 | debug2("input_userauth_pk_ok: fp %s", fp); |
| 703 | xfree(fp); |
Ben Lindstrom | 266dfdf | 2001-03-09 00:12:22 +0000 | [diff] [blame] | 704 | if (!key_equal(key, authctxt->last_key)) { |
| 705 | debug("key != last_key"); |
| 706 | break; |
| 707 | } |
| 708 | sent = sign_and_send_pubkey(authctxt, key, |
| 709 | authctxt->last_key_sign); |
| 710 | } while(0); |
| 711 | |
| 712 | if (key != NULL) |
| 713 | key_free(key); |
| 714 | xfree(pkalg); |
| 715 | xfree(pkblob); |
| 716 | |
| 717 | /* unregister */ |
| 718 | clear_auth_state(authctxt); |
| 719 | dispatch_set(SSH2_MSG_USERAUTH_PK_OK, NULL); |
| 720 | |
| 721 | /* try another method if we did not send a packet*/ |
| 722 | if (sent == 0) |
| 723 | userauth(authctxt, NULL); |
| 724 | |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 725 | } |
| 726 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 727 | int |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 728 | userauth_none(Authctxt *authctxt) |
| 729 | { |
| 730 | /* initial userauth request */ |
| 731 | packet_start(SSH2_MSG_USERAUTH_REQUEST); |
| 732 | packet_put_cstring(authctxt->server_user); |
| 733 | packet_put_cstring(authctxt->service); |
| 734 | packet_put_cstring(authctxt->method->name); |
| 735 | packet_send(); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 736 | return 1; |
| 737 | } |
| 738 | |
| 739 | int |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 740 | userauth_passwd(Authctxt *authctxt) |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 741 | { |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 742 | static int attempt = 0; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 743 | char prompt[80]; |
| 744 | char *password; |
| 745 | |
Damien Miller | d3a1857 | 2000-06-07 19:55:44 +1000 | [diff] [blame] | 746 | if (attempt++ >= options.number_of_password_prompts) |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 747 | return 0; |
| 748 | |
Damien Miller | d3a1857 | 2000-06-07 19:55:44 +1000 | [diff] [blame] | 749 | if(attempt != 1) |
| 750 | error("Permission denied, please try again."); |
| 751 | |
Ben Lindstrom | 03df5bd | 2001-02-10 22:16:41 +0000 | [diff] [blame] | 752 | snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ", |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 753 | authctxt->server_user, authctxt->host); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 754 | password = read_passphrase(prompt, 0); |
| 755 | packet_start(SSH2_MSG_USERAUTH_REQUEST); |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 756 | packet_put_cstring(authctxt->server_user); |
| 757 | packet_put_cstring(authctxt->service); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 758 | packet_put_cstring(authctxt->method->name); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 759 | packet_put_char(0); |
Ben Lindstrom | 5699c5f | 2001-03-05 06:17:49 +0000 | [diff] [blame] | 760 | packet_put_cstring(password); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 761 | memset(password, 0, strlen(password)); |
| 762 | xfree(password); |
Ben Lindstrom | 5699c5f | 2001-03-05 06:17:49 +0000 | [diff] [blame] | 763 | packet_inject_ignore(64); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 764 | packet_send(); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 765 | return 1; |
| 766 | } |
| 767 | |
Ben Lindstrom | 266dfdf | 2001-03-09 00:12:22 +0000 | [diff] [blame] | 768 | void |
| 769 | clear_auth_state(Authctxt *authctxt) |
| 770 | { |
| 771 | /* XXX clear authentication state */ |
| 772 | if (authctxt->last_key != NULL && authctxt->last_key_hint == -1) { |
| 773 | debug3("clear_auth_state: key_free %p", authctxt->last_key); |
| 774 | key_free(authctxt->last_key); |
| 775 | } |
| 776 | authctxt->last_key = NULL; |
| 777 | authctxt->last_key_hint = -2; |
| 778 | authctxt->last_key_sign = NULL; |
| 779 | } |
| 780 | |
Damien Miller | ad833b3 | 2000-08-23 10:46:23 +1000 | [diff] [blame] | 781 | int |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 782 | sign_and_send_pubkey(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback) |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 783 | { |
| 784 | Buffer b; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 785 | u_char *blob, *signature; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 786 | int bloblen, slen; |
Damien Miller | 6536c7d | 2000-06-22 21:32:31 +1000 | [diff] [blame] | 787 | int skip = 0; |
Damien Miller | ad833b3 | 2000-08-23 10:46:23 +1000 | [diff] [blame] | 788 | int ret = -1; |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 789 | int have_sig = 1; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 790 | |
Ben Lindstrom | d121f61 | 2000-12-03 17:00:47 +0000 | [diff] [blame] | 791 | debug3("sign_and_send_pubkey"); |
Ben Lindstrom | 266dfdf | 2001-03-09 00:12:22 +0000 | [diff] [blame] | 792 | |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 793 | if (key_to_blob(k, &blob, &bloblen) == 0) { |
| 794 | /* we cannot handle this key */ |
Ben Lindstrom | d121f61 | 2000-12-03 17:00:47 +0000 | [diff] [blame] | 795 | debug3("sign_and_send_pubkey: cannot handle key"); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 796 | return 0; |
| 797 | } |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 798 | /* data to be signed */ |
| 799 | buffer_init(&b); |
Damien Miller | 50a41ed | 2000-10-16 12:14:42 +1100 | [diff] [blame] | 800 | if (datafellows & SSH_OLD_SESSIONID) { |
Damien Miller | 6536c7d | 2000-06-22 21:32:31 +1000 | [diff] [blame] | 801 | buffer_append(&b, session_id2, session_id2_len); |
Kevin Steves | ef4eea9 | 2001-02-05 12:42:17 +0000 | [diff] [blame] | 802 | skip = session_id2_len; |
Damien Miller | 50a41ed | 2000-10-16 12:14:42 +1100 | [diff] [blame] | 803 | } else { |
| 804 | buffer_put_string(&b, session_id2, session_id2_len); |
| 805 | skip = buffer_len(&b); |
Damien Miller | 6536c7d | 2000-06-22 21:32:31 +1000 | [diff] [blame] | 806 | } |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 807 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 808 | buffer_put_cstring(&b, authctxt->server_user); |
Damien Miller | 30c3d42 | 2000-05-09 11:02:59 +1000 | [diff] [blame] | 809 | buffer_put_cstring(&b, |
Ben Lindstrom | d121f61 | 2000-12-03 17:00:47 +0000 | [diff] [blame] | 810 | datafellows & SSH_BUG_PKSERVICE ? |
Damien Miller | 30c3d42 | 2000-05-09 11:02:59 +1000 | [diff] [blame] | 811 | "ssh-userauth" : |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 812 | authctxt->service); |
Ben Lindstrom | d121f61 | 2000-12-03 17:00:47 +0000 | [diff] [blame] | 813 | if (datafellows & SSH_BUG_PKAUTH) { |
| 814 | buffer_put_char(&b, have_sig); |
| 815 | } else { |
| 816 | buffer_put_cstring(&b, authctxt->method->name); |
| 817 | buffer_put_char(&b, have_sig); |
Kevin Steves | ef4eea9 | 2001-02-05 12:42:17 +0000 | [diff] [blame] | 818 | buffer_put_cstring(&b, key_ssh_name(k)); |
Ben Lindstrom | d121f61 | 2000-12-03 17:00:47 +0000 | [diff] [blame] | 819 | } |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 820 | buffer_put_string(&b, blob, bloblen); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 821 | |
| 822 | /* generate signature */ |
Ben Lindstrom | 266dfdf | 2001-03-09 00:12:22 +0000 | [diff] [blame] | 823 | ret = (*sign_callback)(authctxt, k, &signature, &slen, |
| 824 | buffer_ptr(&b), buffer_len(&b)); |
Damien Miller | ad833b3 | 2000-08-23 10:46:23 +1000 | [diff] [blame] | 825 | if (ret == -1) { |
| 826 | xfree(blob); |
| 827 | buffer_free(&b); |
| 828 | return 0; |
| 829 | } |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 830 | #ifdef DEBUG_PK |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 831 | buffer_dump(&b); |
| 832 | #endif |
Ben Lindstrom | d121f61 | 2000-12-03 17:00:47 +0000 | [diff] [blame] | 833 | if (datafellows & SSH_BUG_PKSERVICE) { |
Damien Miller | 30c3d42 | 2000-05-09 11:02:59 +1000 | [diff] [blame] | 834 | buffer_clear(&b); |
| 835 | buffer_append(&b, session_id2, session_id2_len); |
Ben Lindstrom | 266dfdf | 2001-03-09 00:12:22 +0000 | [diff] [blame] | 836 | skip = session_id2_len; |
Damien Miller | 30c3d42 | 2000-05-09 11:02:59 +1000 | [diff] [blame] | 837 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 838 | buffer_put_cstring(&b, authctxt->server_user); |
| 839 | buffer_put_cstring(&b, authctxt->service); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 840 | buffer_put_cstring(&b, authctxt->method->name); |
| 841 | buffer_put_char(&b, have_sig); |
Ben Lindstrom | d121f61 | 2000-12-03 17:00:47 +0000 | [diff] [blame] | 842 | if (!(datafellows & SSH_BUG_PKAUTH)) |
Kevin Steves | ef4eea9 | 2001-02-05 12:42:17 +0000 | [diff] [blame] | 843 | buffer_put_cstring(&b, key_ssh_name(k)); |
Damien Miller | 30c3d42 | 2000-05-09 11:02:59 +1000 | [diff] [blame] | 844 | buffer_put_string(&b, blob, bloblen); |
| 845 | } |
| 846 | xfree(blob); |
Ben Lindstrom | 266dfdf | 2001-03-09 00:12:22 +0000 | [diff] [blame] | 847 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 848 | /* append signature */ |
| 849 | buffer_put_string(&b, signature, slen); |
| 850 | xfree(signature); |
| 851 | |
| 852 | /* skip session id and packet type */ |
Damien Miller | 6536c7d | 2000-06-22 21:32:31 +1000 | [diff] [blame] | 853 | if (buffer_len(&b) < skip + 1) |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 854 | fatal("userauth_pubkey: internal error"); |
Damien Miller | 6536c7d | 2000-06-22 21:32:31 +1000 | [diff] [blame] | 855 | buffer_consume(&b, skip + 1); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 856 | |
| 857 | /* put remaining data from buffer into packet */ |
| 858 | packet_start(SSH2_MSG_USERAUTH_REQUEST); |
| 859 | packet_put_raw(buffer_ptr(&b), buffer_len(&b)); |
| 860 | buffer_free(&b); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 861 | packet_send(); |
Damien Miller | ad833b3 | 2000-08-23 10:46:23 +1000 | [diff] [blame] | 862 | |
| 863 | return 1; |
Damien Miller | 994cf14 | 2000-07-21 10:19:44 +1000 | [diff] [blame] | 864 | } |
| 865 | |
| 866 | int |
Ben Lindstrom | 266dfdf | 2001-03-09 00:12:22 +0000 | [diff] [blame] | 867 | send_pubkey_test(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback, |
| 868 | int hint) |
Damien Miller | 994cf14 | 2000-07-21 10:19:44 +1000 | [diff] [blame] | 869 | { |
Ben Lindstrom | 266dfdf | 2001-03-09 00:12:22 +0000 | [diff] [blame] | 870 | u_char *blob; |
| 871 | int bloblen, have_sig = 0; |
Damien Miller | 994cf14 | 2000-07-21 10:19:44 +1000 | [diff] [blame] | 872 | |
Ben Lindstrom | 266dfdf | 2001-03-09 00:12:22 +0000 | [diff] [blame] | 873 | debug3("send_pubkey_test"); |
| 874 | |
| 875 | if (key_to_blob(k, &blob, &bloblen) == 0) { |
| 876 | /* we cannot handle this key */ |
| 877 | debug3("send_pubkey_test: cannot handle key"); |
Damien Miller | 994cf14 | 2000-07-21 10:19:44 +1000 | [diff] [blame] | 878 | return 0; |
| 879 | } |
Ben Lindstrom | 266dfdf | 2001-03-09 00:12:22 +0000 | [diff] [blame] | 880 | /* register callback for USERAUTH_PK_OK message */ |
| 881 | authctxt->last_key_sign = sign_callback; |
| 882 | authctxt->last_key_hint = hint; |
| 883 | authctxt->last_key = k; |
| 884 | dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok); |
Damien Miller | 994cf14 | 2000-07-21 10:19:44 +1000 | [diff] [blame] | 885 | |
Ben Lindstrom | 266dfdf | 2001-03-09 00:12:22 +0000 | [diff] [blame] | 886 | packet_start(SSH2_MSG_USERAUTH_REQUEST); |
| 887 | packet_put_cstring(authctxt->server_user); |
| 888 | packet_put_cstring(authctxt->service); |
| 889 | packet_put_cstring(authctxt->method->name); |
| 890 | packet_put_char(have_sig); |
| 891 | if (!(datafellows & SSH_BUG_PKAUTH)) |
| 892 | packet_put_cstring(key_ssh_name(k)); |
| 893 | packet_put_string(blob, bloblen); |
| 894 | xfree(blob); |
| 895 | packet_send(); |
| 896 | return 1; |
| 897 | } |
| 898 | |
| 899 | Key * |
| 900 | load_identity_file(char *filename) |
| 901 | { |
| 902 | Key *private; |
| 903 | char prompt[300], *passphrase; |
Ben Lindstrom | d0fca42 | 2001-03-26 13:44:06 +0000 | [diff] [blame^] | 904 | int quit, i; |
Ben Lindstrom | 329782e | 2001-03-10 17:08:59 +0000 | [diff] [blame] | 905 | struct stat st; |
Ben Lindstrom | 266dfdf | 2001-03-09 00:12:22 +0000 | [diff] [blame] | 906 | |
Ben Lindstrom | 329782e | 2001-03-10 17:08:59 +0000 | [diff] [blame] | 907 | if (stat(filename, &st) < 0) { |
| 908 | debug3("no such identity: %s", filename); |
| 909 | return NULL; |
| 910 | } |
Ben Lindstrom | d0fca42 | 2001-03-26 13:44:06 +0000 | [diff] [blame^] | 911 | private = key_load_private_type(KEY_UNSPEC, filename, "", NULL); |
| 912 | if (private == NULL) { |
| 913 | if (options.batch_mode) |
Ben Lindstrom | 266dfdf | 2001-03-09 00:12:22 +0000 | [diff] [blame] | 914 | return NULL; |
Damien Miller | 994cf14 | 2000-07-21 10:19:44 +1000 | [diff] [blame] | 915 | snprintf(prompt, sizeof prompt, |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 916 | "Enter passphrase for key '%.100s': ", filename); |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 917 | for (i = 0; i < options.number_of_password_prompts; i++) { |
| 918 | passphrase = read_passphrase(prompt, 0); |
| 919 | if (strcmp(passphrase, "") != 0) { |
Ben Lindstrom | d0fca42 | 2001-03-26 13:44:06 +0000 | [diff] [blame^] | 920 | private = key_load_private_type(KEY_UNSPEC, filename, |
| 921 | passphrase, NULL); |
Ben Lindstrom | 266dfdf | 2001-03-09 00:12:22 +0000 | [diff] [blame] | 922 | quit = 0; |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 923 | } else { |
| 924 | debug2("no passphrase given, try next key"); |
Ben Lindstrom | 266dfdf | 2001-03-09 00:12:22 +0000 | [diff] [blame] | 925 | quit = 1; |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 926 | } |
| 927 | memset(passphrase, 0, strlen(passphrase)); |
| 928 | xfree(passphrase); |
Ben Lindstrom | d0fca42 | 2001-03-26 13:44:06 +0000 | [diff] [blame^] | 929 | if (private != NULL || quit) |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 930 | break; |
| 931 | debug2("bad passphrase given, try again..."); |
| 932 | } |
Damien Miller | 994cf14 | 2000-07-21 10:19:44 +1000 | [diff] [blame] | 933 | } |
Ben Lindstrom | 266dfdf | 2001-03-09 00:12:22 +0000 | [diff] [blame] | 934 | return private; |
| 935 | } |
| 936 | |
| 937 | int |
| 938 | identity_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, int *lenp, |
| 939 | u_char *data, int datalen) |
| 940 | { |
| 941 | Key *private; |
| 942 | int idx, ret; |
| 943 | |
| 944 | idx = authctxt->last_key_hint; |
| 945 | if (idx < 0) |
| 946 | return -1; |
| 947 | private = load_identity_file(options.identity_files[idx]); |
| 948 | if (private == NULL) |
| 949 | return -1; |
| 950 | ret = key_sign(private, sigp, lenp, data, datalen); |
| 951 | key_free(private); |
Damien Miller | ad833b3 | 2000-08-23 10:46:23 +1000 | [diff] [blame] | 952 | return ret; |
| 953 | } |
| 954 | |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 955 | int agent_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, int *lenp, |
| 956 | u_char *data, int datalen) |
Damien Miller | ad833b3 | 2000-08-23 10:46:23 +1000 | [diff] [blame] | 957 | { |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 958 | return ssh_agent_sign(authctxt->agent, key, sigp, lenp, data, datalen); |
Damien Miller | ad833b3 | 2000-08-23 10:46:23 +1000 | [diff] [blame] | 959 | } |
| 960 | |
Ben Lindstrom | 266dfdf | 2001-03-09 00:12:22 +0000 | [diff] [blame] | 961 | int key_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, int *lenp, |
| 962 | u_char *data, int datalen) |
| 963 | { |
| 964 | return key_sign(key, sigp, lenp, data, datalen); |
| 965 | } |
| 966 | |
Damien Miller | ad833b3 | 2000-08-23 10:46:23 +1000 | [diff] [blame] | 967 | int |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 968 | userauth_pubkey_agent(Authctxt *authctxt) |
Damien Miller | ad833b3 | 2000-08-23 10:46:23 +1000 | [diff] [blame] | 969 | { |
| 970 | static int called = 0; |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 971 | int ret = 0; |
Damien Miller | ad833b3 | 2000-08-23 10:46:23 +1000 | [diff] [blame] | 972 | char *comment; |
| 973 | Key *k; |
Damien Miller | ad833b3 | 2000-08-23 10:46:23 +1000 | [diff] [blame] | 974 | |
| 975 | if (called == 0) { |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 976 | if (ssh_get_num_identities(authctxt->agent, 2) == 0) |
| 977 | debug2("userauth_pubkey_agent: no keys at all"); |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 978 | called = 1; |
Damien Miller | ad833b3 | 2000-08-23 10:46:23 +1000 | [diff] [blame] | 979 | } |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 980 | k = ssh_get_next_identity(authctxt->agent, &comment, 2); |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 981 | if (k == NULL) { |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 982 | debug2("userauth_pubkey_agent: no more keys"); |
| 983 | } else { |
Ben Lindstrom | 266dfdf | 2001-03-09 00:12:22 +0000 | [diff] [blame] | 984 | debug("userauth_pubkey_agent: testing agent key %s", comment); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 985 | xfree(comment); |
Ben Lindstrom | 266dfdf | 2001-03-09 00:12:22 +0000 | [diff] [blame] | 986 | ret = send_pubkey_test(authctxt, k, agent_sign_cb, -1); |
| 987 | if (ret == 0) |
| 988 | key_free(k); |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 989 | } |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 990 | if (ret == 0) |
| 991 | debug2("userauth_pubkey_agent: no message sent"); |
Damien Miller | ad833b3 | 2000-08-23 10:46:23 +1000 | [diff] [blame] | 992 | return ret; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 993 | } |
| 994 | |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 995 | int |
| 996 | userauth_pubkey(Authctxt *authctxt) |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 997 | { |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 998 | static int idx = 0; |
| 999 | int sent = 0; |
Ben Lindstrom | 266dfdf | 2001-03-09 00:12:22 +0000 | [diff] [blame] | 1000 | Key *key; |
| 1001 | char *filename; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1002 | |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1003 | if (authctxt->agent != NULL) { |
| 1004 | do { |
| 1005 | sent = userauth_pubkey_agent(authctxt); |
| 1006 | } while(!sent && authctxt->agent->howmany > 0); |
| 1007 | } |
| 1008 | while (!sent && idx < options.num_identity_files) { |
Ben Lindstrom | 266dfdf | 2001-03-09 00:12:22 +0000 | [diff] [blame] | 1009 | key = options.identity_keys[idx]; |
| 1010 | filename = options.identity_files[idx]; |
| 1011 | if (key == NULL) { |
| 1012 | debug("try privkey: %s", filename); |
| 1013 | key = load_identity_file(filename); |
| 1014 | if (key != NULL) { |
| 1015 | sent = sign_and_send_pubkey(authctxt, key, |
| 1016 | key_sign_cb); |
| 1017 | key_free(key); |
| 1018 | } |
| 1019 | } else if (key->type != KEY_RSA1) { |
| 1020 | debug("try pubkey: %s", filename); |
| 1021 | sent = send_pubkey_test(authctxt, key, |
| 1022 | identity_sign_cb, idx); |
| 1023 | } |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1024 | idx++; |
| 1025 | } |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 1026 | return sent; |
| 1027 | } |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1028 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 1029 | /* |
| 1030 | * Send userauth request message specifying keyboard-interactive method. |
| 1031 | */ |
| 1032 | int |
| 1033 | userauth_kbdint(Authctxt *authctxt) |
| 1034 | { |
| 1035 | static int attempt = 0; |
| 1036 | |
| 1037 | if (attempt++ >= options.number_of_password_prompts) |
| 1038 | return 0; |
| 1039 | |
| 1040 | debug2("userauth_kbdint"); |
| 1041 | packet_start(SSH2_MSG_USERAUTH_REQUEST); |
| 1042 | packet_put_cstring(authctxt->server_user); |
| 1043 | packet_put_cstring(authctxt->service); |
| 1044 | packet_put_cstring(authctxt->method->name); |
| 1045 | packet_put_cstring(""); /* lang */ |
| 1046 | packet_put_cstring(options.kbd_interactive_devices ? |
| 1047 | options.kbd_interactive_devices : ""); |
| 1048 | packet_send(); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 1049 | |
| 1050 | dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req); |
| 1051 | return 1; |
| 1052 | } |
| 1053 | |
| 1054 | /* |
Ben Lindstrom | 03df5bd | 2001-02-10 22:16:41 +0000 | [diff] [blame] | 1055 | * parse INFO_REQUEST, prompt user and send INFO_RESPONSE |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 1056 | */ |
| 1057 | void |
| 1058 | input_userauth_info_req(int type, int plen, void *ctxt) |
| 1059 | { |
| 1060 | Authctxt *authctxt = ctxt; |
Ben Lindstrom | 03df5bd | 2001-02-10 22:16:41 +0000 | [diff] [blame] | 1061 | char *name, *inst, *lang, *prompt, *response; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 1062 | u_int num_prompts, i; |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 1063 | int echo = 0; |
| 1064 | |
| 1065 | debug2("input_userauth_info_req"); |
| 1066 | |
| 1067 | if (authctxt == NULL) |
| 1068 | fatal("input_userauth_info_req: no authentication context"); |
| 1069 | |
| 1070 | name = packet_get_string(NULL); |
| 1071 | inst = packet_get_string(NULL); |
| 1072 | lang = packet_get_string(NULL); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 1073 | if (strlen(name) > 0) |
| 1074 | cli_mesg(name); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 1075 | if (strlen(inst) > 0) |
| 1076 | cli_mesg(inst); |
Ben Lindstrom | 03df5bd | 2001-02-10 22:16:41 +0000 | [diff] [blame] | 1077 | xfree(name); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 1078 | xfree(inst); |
Ben Lindstrom | 03df5bd | 2001-02-10 22:16:41 +0000 | [diff] [blame] | 1079 | xfree(lang); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 1080 | |
| 1081 | num_prompts = packet_get_int(); |
| 1082 | /* |
| 1083 | * Begin to build info response packet based on prompts requested. |
| 1084 | * We commit to providing the correct number of responses, so if |
| 1085 | * further on we run into a problem that prevents this, we have to |
| 1086 | * be sure and clean this up and send a correct error response. |
| 1087 | */ |
| 1088 | packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE); |
| 1089 | packet_put_int(num_prompts); |
| 1090 | |
| 1091 | for (i = 0; i < num_prompts; i++) { |
| 1092 | prompt = packet_get_string(NULL); |
| 1093 | echo = packet_get_char(); |
| 1094 | |
| 1095 | response = cli_prompt(prompt, echo); |
| 1096 | |
Ben Lindstrom | 5699c5f | 2001-03-05 06:17:49 +0000 | [diff] [blame] | 1097 | packet_put_cstring(response); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 1098 | memset(response, 0, strlen(response)); |
| 1099 | xfree(response); |
| 1100 | xfree(prompt); |
| 1101 | } |
| 1102 | packet_done(); /* done with parsing incoming message. */ |
| 1103 | |
Ben Lindstrom | 5699c5f | 2001-03-05 06:17:49 +0000 | [diff] [blame] | 1104 | packet_inject_ignore(64); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 1105 | packet_send(); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 1106 | } |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 1107 | |
| 1108 | /* find auth method */ |
| 1109 | |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 1110 | /* |
| 1111 | * given auth method name, if configurable options permit this method fill |
| 1112 | * in auth_ident field and return true, otherwise return false. |
| 1113 | */ |
| 1114 | int |
| 1115 | authmethod_is_enabled(Authmethod *method) |
| 1116 | { |
| 1117 | if (method == NULL) |
| 1118 | return 0; |
| 1119 | /* return false if options indicate this method is disabled */ |
| 1120 | if (method->enabled == NULL || *method->enabled == 0) |
| 1121 | return 0; |
| 1122 | /* return false if batch mode is enabled but method needs interactive mode */ |
| 1123 | if (method->batch_flag != NULL && *method->batch_flag != 0) |
| 1124 | return 0; |
| 1125 | return 1; |
| 1126 | } |
| 1127 | |
| 1128 | Authmethod * |
| 1129 | authmethod_lookup(const char *name) |
| 1130 | { |
| 1131 | Authmethod *method = NULL; |
| 1132 | if (name != NULL) |
| 1133 | for (method = authmethods; method->name != NULL; method++) |
| 1134 | if (strcmp(name, method->name) == 0) |
| 1135 | return method; |
| 1136 | debug2("Unrecognized authentication method name: %s", name ? name : "NULL"); |
| 1137 | return NULL; |
| 1138 | } |
| 1139 | |
Ben Lindstrom | b9be60a | 2001-03-11 01:49:19 +0000 | [diff] [blame] | 1140 | /* XXX internal state */ |
| 1141 | static Authmethod *current = NULL; |
| 1142 | static char *supported = NULL; |
| 1143 | static char *preferred = NULL; |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 1144 | /* |
| 1145 | * Given the authentication method list sent by the server, return the |
| 1146 | * next method we should try. If the server initially sends a nil list, |
Ben Lindstrom | b9be60a | 2001-03-11 01:49:19 +0000 | [diff] [blame] | 1147 | * use a built-in default list. |
Kevin Steves | ef4eea9 | 2001-02-05 12:42:17 +0000 | [diff] [blame] | 1148 | */ |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 1149 | Authmethod * |
| 1150 | authmethod_get(char *authlist) |
| 1151 | { |
Ben Lindstrom | b9be60a | 2001-03-11 01:49:19 +0000 | [diff] [blame] | 1152 | |
| 1153 | char *name = NULL; |
| 1154 | int next; |
Kevin Steves | ef4eea9 | 2001-02-05 12:42:17 +0000 | [diff] [blame] | 1155 | |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 1156 | /* Use a suitable default if we're passed a nil list. */ |
| 1157 | if (authlist == NULL || strlen(authlist) == 0) |
Ben Lindstrom | b9be60a | 2001-03-11 01:49:19 +0000 | [diff] [blame] | 1158 | authlist = options.preferred_authentications; |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 1159 | |
Ben Lindstrom | b9be60a | 2001-03-11 01:49:19 +0000 | [diff] [blame] | 1160 | if (supported == NULL || strcmp(authlist, supported) != 0) { |
| 1161 | debug3("start over, passed a different list %s", authlist); |
| 1162 | if (supported != NULL) |
| 1163 | xfree(supported); |
| 1164 | supported = xstrdup(authlist); |
| 1165 | preferred = options.preferred_authentications; |
| 1166 | debug3("preferred %s", preferred); |
| 1167 | current = NULL; |
| 1168 | } else if (current != NULL && authmethod_is_enabled(current)) |
| 1169 | return current; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1170 | |
Ben Lindstrom | b9be60a | 2001-03-11 01:49:19 +0000 | [diff] [blame] | 1171 | for (;;) { |
| 1172 | if ((name = match_list(preferred, supported, &next)) == NULL) { |
| 1173 | debug("no more auth methods to try"); |
| 1174 | current = NULL; |
| 1175 | return NULL; |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 1176 | } |
Ben Lindstrom | b9be60a | 2001-03-11 01:49:19 +0000 | [diff] [blame] | 1177 | preferred += next; |
| 1178 | debug3("authmethod_lookup %s", name); |
| 1179 | debug3("remaining preferred: %s", preferred); |
| 1180 | if ((current = authmethod_lookup(name)) != NULL && |
| 1181 | authmethod_is_enabled(current)) { |
| 1182 | debug3("authmethod_is_enabled %s", name); |
| 1183 | debug("next auth method to try is %s", name); |
| 1184 | return current; |
| 1185 | } |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1186 | } |
Ben Lindstrom | b9be60a | 2001-03-11 01:49:19 +0000 | [diff] [blame] | 1187 | } |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 1188 | |
Ben Lindstrom | b9be60a | 2001-03-11 01:49:19 +0000 | [diff] [blame] | 1189 | |
| 1190 | #define DELIM "," |
| 1191 | char * |
| 1192 | authmethods_get(void) |
| 1193 | { |
| 1194 | Authmethod *method = NULL; |
| 1195 | char buf[1024]; |
| 1196 | |
| 1197 | buf[0] = '\0'; |
| 1198 | for (method = authmethods; method->name != NULL; method++) { |
| 1199 | if (authmethod_is_enabled(method)) { |
| 1200 | if (buf[0] != '\0') |
| 1201 | strlcat(buf, DELIM, sizeof buf); |
| 1202 | strlcat(buf, method->name, sizeof buf); |
| 1203 | } |
Damien Miller | 62cee00 | 2000-09-23 17:15:56 +1100 | [diff] [blame] | 1204 | } |
Ben Lindstrom | b9be60a | 2001-03-11 01:49:19 +0000 | [diff] [blame] | 1205 | return xstrdup(buf); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1206 | } |