Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
| 3 | * All rights reserved |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 4 | * |
| 5 | * As far as I am concerned, the code I have written for this software |
| 6 | * can be used freely for any purpose. Any derived versions of this |
| 7 | * software must be clearly marked as such, and if the derived work is |
| 8 | * incompatible with the protocol description in the RFC file, it must be |
| 9 | * called by a name other than "ssh" or "Secure Shell". |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 10 | */ |
| 11 | |
| 12 | #include "includes.h" |
Damien Miller | aef7a09 | 2002-01-22 23:07:52 +1100 | [diff] [blame] | 13 | RCSID("$OpenBSD: auth1.c,v 1.28 2001/12/25 18:53:00 markus Exp $"); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 14 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 15 | #include "xmalloc.h" |
| 16 | #include "rsa.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 17 | #include "ssh1.h" |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 18 | #include "packet.h" |
| 19 | #include "buffer.h" |
| 20 | #include "mpaux.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 21 | #include "log.h" |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 22 | #include "servconf.h" |
| 23 | #include "compat.h" |
| 24 | #include "auth.h" |
| 25 | #include "session.h" |
Ben Lindstrom | 086cf21 | 2001-03-05 05:56:40 +0000 | [diff] [blame] | 26 | #include "misc.h" |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 27 | #include "uidswap.h" |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 28 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 29 | /* import */ |
| 30 | extern ServerOptions options; |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 31 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 32 | /* |
| 33 | * convert ssh auth msg type into description |
| 34 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 35 | static char * |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 36 | get_authname(int type) |
| 37 | { |
| 38 | static char buf[1024]; |
| 39 | switch (type) { |
| 40 | case SSH_CMSG_AUTH_PASSWORD: |
| 41 | return "password"; |
| 42 | case SSH_CMSG_AUTH_RSA: |
| 43 | return "rsa"; |
| 44 | case SSH_CMSG_AUTH_RHOSTS_RSA: |
| 45 | return "rhosts-rsa"; |
| 46 | case SSH_CMSG_AUTH_RHOSTS: |
| 47 | return "rhosts"; |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 48 | case SSH_CMSG_AUTH_TIS: |
| 49 | case SSH_CMSG_AUTH_TIS_RESPONSE: |
| 50 | return "challenge-response"; |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 51 | #if defined(KRB4) || defined(KRB5) |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 52 | case SSH_CMSG_AUTH_KERBEROS: |
| 53 | return "kerberos"; |
| 54 | #endif |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 55 | } |
| 56 | snprintf(buf, sizeof buf, "bad-auth-msg-%d", type); |
| 57 | return buf; |
| 58 | } |
| 59 | |
| 60 | /* |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 61 | * read packets, try to authenticate the user and |
| 62 | * return only if authentication is successful |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 63 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 64 | static void |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 65 | do_authloop(Authctxt *authctxt) |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 66 | { |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 67 | int authenticated = 0; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 68 | u_int bits; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 69 | RSA *client_host_key; |
| 70 | BIGNUM *n; |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 71 | char *client_user, *password; |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 72 | char info[1024]; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 73 | u_int dlen; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 74 | int plen, nlen, elen; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 75 | u_int ulen; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 76 | int type = 0; |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 77 | struct passwd *pw = authctxt->pw; |
| 78 | |
| 79 | debug("Attempting authentication for %s%.100s.", |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 80 | authctxt->valid ? "" : "illegal user ", authctxt->user); |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 81 | |
| 82 | /* If the user has no password, accept authentication immediately. */ |
| 83 | if (options.password_authentication && |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 84 | #if defined(KRB4) || defined(KRB5) |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 85 | (!options.kerberos_authentication || options.kerberos_or_local_passwd) && |
| 86 | #endif |
Ben Lindstrom | b100ec9 | 2001-01-19 05:37:32 +0000 | [diff] [blame] | 87 | #ifdef USE_PAM |
Kevin Steves | bca8c8f | 2001-02-13 11:26:21 +0000 | [diff] [blame] | 88 | auth_pam_password(pw, "")) { |
Damien Miller | 92ddb7d | 2001-02-14 01:25:23 +1100 | [diff] [blame] | 89 | #elif defined(HAVE_OSF_SIA) |
| 90 | 0) { |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 91 | #else |
Damien Miller | 60396b0 | 2001-02-18 17:01:00 +1100 | [diff] [blame] | 92 | auth_password(authctxt, "")) { |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 93 | #endif |
| 94 | auth_log(authctxt, 1, "without authentication", ""); |
| 95 | return; |
| 96 | } |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 97 | |
| 98 | /* Indicate that authentication is needed. */ |
| 99 | packet_start(SSH_SMSG_FAILURE); |
| 100 | packet_send(); |
| 101 | packet_write_wait(); |
| 102 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 103 | client_user = NULL; |
| 104 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 105 | for (;;) { |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 106 | /* default to fail */ |
| 107 | authenticated = 0; |
| 108 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 109 | info[0] = '\0'; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 110 | |
| 111 | /* Get a packet from the client. */ |
| 112 | type = packet_read(&plen); |
| 113 | |
| 114 | /* Process the packet. */ |
| 115 | switch (type) { |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 116 | |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 117 | #if defined(KRB4) || defined(KRB5) |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 118 | case SSH_CMSG_AUTH_KERBEROS: |
| 119 | if (!options.kerberos_authentication) { |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 120 | verbose("Kerberos authentication disabled."); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 121 | } else { |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 122 | char *kdata = packet_get_string(&dlen); |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 123 | |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 124 | packet_integrity_check(plen, 4 + dlen, type); |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 125 | |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 126 | if (kdata[0] == 4) { /* KRB_PROT_VERSION */ |
| 127 | #ifdef KRB4 |
| 128 | KTEXT_ST tkt; |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 129 | |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 130 | tkt.length = dlen; |
| 131 | if (tkt.length < MAX_KTXT_LEN) |
| 132 | memcpy(tkt.dat, kdata, tkt.length); |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 133 | |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 134 | if (auth_krb4(authctxt, &tkt, &client_user)) { |
| 135 | authenticated = 1; |
| 136 | snprintf(info, sizeof(info), |
| 137 | " tktuser %.100s", |
| 138 | client_user); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 139 | } |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 140 | #endif /* KRB4 */ |
| 141 | } else { |
| 142 | #ifdef KRB5 |
| 143 | krb5_data tkt; |
| 144 | tkt.length = dlen; |
| 145 | tkt.data = kdata; |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 146 | |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 147 | if (auth_krb5(authctxt, &tkt, &client_user)) { |
| 148 | authenticated = 1; |
| 149 | snprintf(info, sizeof(info), |
| 150 | " tktuser %.100s", |
| 151 | client_user); |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 152 | } |
| 153 | #endif /* KRB5 */ |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 154 | } |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 155 | xfree(kdata); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 156 | } |
| 157 | break; |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 158 | #endif /* KRB4 || KRB5 */ |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 159 | |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 160 | #if defined(AFS) || defined(KRB5) |
| 161 | /* XXX - punt on backward compatibility here. */ |
| 162 | case SSH_CMSG_HAVE_KERBEROS_TGT: |
| 163 | packet_send_debug("Kerberos TGT passing disabled before authentication."); |
| 164 | break; |
| 165 | #ifdef AFS |
| 166 | case SSH_CMSG_HAVE_AFS_TOKEN: |
| 167 | packet_send_debug("AFS token passing disabled before authentication."); |
| 168 | break; |
| 169 | #endif /* AFS */ |
| 170 | #endif /* AFS || KRB5 */ |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 171 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 172 | case SSH_CMSG_AUTH_RHOSTS: |
| 173 | if (!options.rhosts_authentication) { |
| 174 | verbose("Rhosts authentication disabled."); |
| 175 | break; |
| 176 | } |
| 177 | /* |
| 178 | * Get client user name. Note that we just have to |
| 179 | * trust the client; this is one reason why rhosts |
| 180 | * authentication is insecure. (Another is |
| 181 | * IP-spoofing on a local network.) |
| 182 | */ |
| 183 | client_user = packet_get_string(&ulen); |
| 184 | packet_integrity_check(plen, 4 + ulen, type); |
| 185 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 186 | /* Try to authenticate using /etc/hosts.equiv and .rhosts. */ |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 187 | authenticated = auth_rhosts(pw, client_user); |
| 188 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 189 | snprintf(info, sizeof info, " ruser %.100s", client_user); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 190 | break; |
| 191 | |
| 192 | case SSH_CMSG_AUTH_RHOSTS_RSA: |
| 193 | if (!options.rhosts_rsa_authentication) { |
| 194 | verbose("Rhosts with RSA authentication disabled."); |
| 195 | break; |
| 196 | } |
| 197 | /* |
| 198 | * Get client user name. Note that we just have to |
| 199 | * trust the client; root on the client machine can |
| 200 | * claim to be any user. |
| 201 | */ |
| 202 | client_user = packet_get_string(&ulen); |
| 203 | |
| 204 | /* Get the client host key. */ |
| 205 | client_host_key = RSA_new(); |
| 206 | if (client_host_key == NULL) |
| 207 | fatal("RSA_new failed"); |
| 208 | client_host_key->e = BN_new(); |
| 209 | client_host_key->n = BN_new(); |
| 210 | if (client_host_key->e == NULL || client_host_key->n == NULL) |
| 211 | fatal("BN_new failed"); |
| 212 | bits = packet_get_int(); |
| 213 | packet_get_bignum(client_host_key->e, &elen); |
| 214 | packet_get_bignum(client_host_key->n, &nlen); |
| 215 | |
| 216 | if (bits != BN_num_bits(client_host_key->n)) |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 217 | verbose("Warning: keysize mismatch for client_host_key: " |
Damien Miller | bd483e7 | 2000-04-30 10:00:53 +1000 | [diff] [blame] | 218 | "actual %d, announced %d", BN_num_bits(client_host_key->n), bits); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 219 | packet_integrity_check(plen, (4 + ulen) + 4 + elen + nlen, type); |
| 220 | |
| 221 | authenticated = auth_rhosts_rsa(pw, client_user, client_host_key); |
| 222 | RSA_free(client_host_key); |
| 223 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 224 | snprintf(info, sizeof info, " ruser %.100s", client_user); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 225 | break; |
| 226 | |
| 227 | case SSH_CMSG_AUTH_RSA: |
| 228 | if (!options.rsa_authentication) { |
| 229 | verbose("RSA authentication disabled."); |
| 230 | break; |
| 231 | } |
| 232 | /* RSA authentication requested. */ |
| 233 | n = BN_new(); |
Damien Miller | aef7a09 | 2002-01-22 23:07:52 +1100 | [diff] [blame] | 234 | if (n == NULL) |
| 235 | fatal("BN_new failed"); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 236 | packet_get_bignum(n, &nlen); |
| 237 | packet_integrity_check(plen, nlen, type); |
| 238 | authenticated = auth_rsa(pw, n); |
| 239 | BN_clear_free(n); |
| 240 | break; |
| 241 | |
| 242 | case SSH_CMSG_AUTH_PASSWORD: |
| 243 | if (!options.password_authentication) { |
| 244 | verbose("Password authentication disabled."); |
| 245 | break; |
| 246 | } |
| 247 | /* |
| 248 | * Read user password. It is in plain text, but was |
| 249 | * transmitted over the encrypted channel so it is |
| 250 | * not visible to an outside observer. |
| 251 | */ |
| 252 | password = packet_get_string(&dlen); |
| 253 | packet_integrity_check(plen, 4 + dlen, type); |
| 254 | |
| 255 | #ifdef USE_PAM |
| 256 | /* Do PAM auth with password */ |
| 257 | authenticated = auth_pam_password(pw, password); |
Damien Miller | b8c656e | 2000-06-28 15:22:41 +1000 | [diff] [blame] | 258 | #elif defined(HAVE_OSF_SIA) |
| 259 | /* Do SIA auth with password */ |
Damien Miller | 92ddb7d | 2001-02-14 01:25:23 +1100 | [diff] [blame] | 260 | authenticated = auth_sia_password(authctxt->user, |
| 261 | password); |
Damien Miller | b8c656e | 2000-06-28 15:22:41 +1000 | [diff] [blame] | 262 | #else /* !USE_PAM && !HAVE_OSF_SIA */ |
Kevin Steves | 12aaa04 | 2001-01-24 21:23:39 +0000 | [diff] [blame] | 263 | /* Try authentication with the password. */ |
Damien Miller | 60396b0 | 2001-02-18 17:01:00 +1100 | [diff] [blame] | 264 | authenticated = auth_password(authctxt, password); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 265 | #endif /* USE_PAM */ |
| 266 | |
| 267 | memset(password, 0, strlen(password)); |
| 268 | xfree(password); |
| 269 | break; |
| 270 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 271 | case SSH_CMSG_AUTH_TIS: |
| 272 | debug("rcvd SSH_CMSG_AUTH_TIS"); |
Ben Lindstrom | 551ea37 | 2001-06-05 18:56:16 +0000 | [diff] [blame] | 273 | if (options.challenge_response_authentication == 1) { |
| 274 | char *challenge = get_challenge(authctxt); |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 275 | if (challenge != NULL) { |
| 276 | debug("sending challenge '%s'", challenge); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 277 | packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE); |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 278 | packet_put_cstring(challenge); |
Ben Lindstrom | 551ea37 | 2001-06-05 18:56:16 +0000 | [diff] [blame] | 279 | xfree(challenge); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 280 | packet_send(); |
| 281 | packet_write_wait(); |
| 282 | continue; |
| 283 | } |
| 284 | } |
| 285 | break; |
| 286 | case SSH_CMSG_AUTH_TIS_RESPONSE: |
| 287 | debug("rcvd SSH_CMSG_AUTH_TIS_RESPONSE"); |
Ben Lindstrom | 551ea37 | 2001-06-05 18:56:16 +0000 | [diff] [blame] | 288 | if (options.challenge_response_authentication == 1) { |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 289 | char *response = packet_get_string(&dlen); |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 290 | debug("got response '%s'", response); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 291 | packet_integrity_check(plen, 4 + dlen, type); |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 292 | authenticated = verify_response(authctxt, response); |
| 293 | memset(response, 'r', dlen); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 294 | xfree(response); |
| 295 | } |
| 296 | break; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 297 | |
| 298 | default: |
| 299 | /* |
| 300 | * Any unknown messages will be ignored (and failure |
| 301 | * returned) during authentication. |
| 302 | */ |
| 303 | log("Unknown message during authentication: type %d", type); |
| 304 | break; |
| 305 | } |
Damien Miller | 60396b0 | 2001-02-18 17:01:00 +1100 | [diff] [blame] | 306 | #ifdef BSD_AUTH |
| 307 | if (authctxt->as) { |
| 308 | auth_close(authctxt->as); |
| 309 | authctxt->as = NULL; |
| 310 | } |
| 311 | #endif |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 312 | if (!authctxt->valid && authenticated) |
| 313 | fatal("INTERNAL ERROR: authenticated invalid user %s", |
| 314 | authctxt->user); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 315 | |
Kevin Steves | ef4eea9 | 2001-02-05 12:42:17 +0000 | [diff] [blame] | 316 | #ifdef HAVE_CYGWIN |
| 317 | if (authenticated && |
Damien Miller | 0dea79d | 2001-12-29 14:08:28 +1100 | [diff] [blame] | 318 | !check_nt_auth(type == SSH_CMSG_AUTH_PASSWORD, pw)) { |
Damien Miller | bac2d8a | 2000-09-05 16:13:06 +1100 | [diff] [blame] | 319 | packet_disconnect("Authentication rejected for uid %d.", |
Damien Miller | 0dea79d | 2001-12-29 14:08:28 +1100 | [diff] [blame] | 320 | pw == NULL ? -1 : pw->pw_uid); |
Damien Miller | bac2d8a | 2000-09-05 16:13:06 +1100 | [diff] [blame] | 321 | authenticated = 0; |
| 322 | } |
Ben Lindstrom | 5dc8150 | 2001-01-19 06:10:29 +0000 | [diff] [blame] | 323 | #else |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 324 | /* Special handling for root */ |
Ben Lindstrom | d8a9021 | 2001-02-15 03:08:27 +0000 | [diff] [blame] | 325 | if (authenticated && authctxt->pw->pw_uid == 0 && |
| 326 | !auth_root_allowed(get_authname(type))) |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 327 | authenticated = 0; |
Ben Lindstrom | 5dc8150 | 2001-01-19 06:10:29 +0000 | [diff] [blame] | 328 | #endif |
Kevin Steves | ef4eea9 | 2001-02-05 12:42:17 +0000 | [diff] [blame] | 329 | #ifdef USE_PAM |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 330 | if (authenticated && !do_pam_account(pw->pw_name, client_user)) |
| 331 | authenticated = 0; |
| 332 | #endif |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 333 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 334 | /* Log before sending the reply */ |
| 335 | auth_log(authctxt, authenticated, get_authname(type), info); |
| 336 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 337 | if (client_user != NULL) { |
| 338 | xfree(client_user); |
| 339 | client_user = NULL; |
| 340 | } |
| 341 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 342 | if (authenticated) |
| 343 | return; |
| 344 | |
Kevin Steves | 12aaa04 | 2001-01-24 21:23:39 +0000 | [diff] [blame] | 345 | if (authctxt->failures++ > AUTH_FAIL_MAX) { |
Kevin Steves | ef4eea9 | 2001-02-05 12:42:17 +0000 | [diff] [blame] | 346 | #ifdef WITH_AIXAUTHENTICATE |
| 347 | loginfailed(authctxt->user, |
| 348 | get_canonical_hostname(options.reverse_mapping_check), |
Damien Miller | 3380426 | 2001-02-04 23:20:18 +1100 | [diff] [blame] | 349 | "ssh"); |
Damien Miller | d2c208a | 2000-05-17 22:00:02 +1000 | [diff] [blame] | 350 | #endif /* WITH_AIXAUTHENTICATE */ |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 351 | packet_disconnect(AUTH_FAIL_MSG, authctxt->user); |
Damien Miller | d2c208a | 2000-05-17 22:00:02 +1000 | [diff] [blame] | 352 | } |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 353 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 354 | packet_start(SSH_SMSG_FAILURE); |
| 355 | packet_send(); |
| 356 | packet_write_wait(); |
| 357 | } |
| 358 | } |
| 359 | |
| 360 | /* |
| 361 | * Performs authentication of an incoming connection. Session key has already |
| 362 | * been exchanged and encryption is enabled. |
| 363 | */ |
| 364 | void |
Ben Lindstrom | 3c36bb2 | 2001-12-06 17:55:26 +0000 | [diff] [blame] | 365 | do_authentication(void) |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 366 | { |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 367 | Authctxt *authctxt; |
| 368 | struct passwd *pw; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 369 | int plen; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 370 | u_int ulen; |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 371 | char *p, *user, *style = NULL; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 372 | |
| 373 | /* Get the name of the user that we wish to log in as. */ |
| 374 | packet_read_expect(&plen, SSH_CMSG_USER); |
| 375 | |
| 376 | /* Get the user name. */ |
| 377 | user = packet_get_string(&ulen); |
| 378 | packet_integrity_check(plen, (4 + ulen), SSH_CMSG_USER); |
| 379 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 380 | if ((style = strchr(user, ':')) != NULL) |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 381 | *style++ = '\0'; |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 382 | |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 383 | /* XXX - SSH.com Kerberos v5 braindeath. */ |
| 384 | if ((p = strchr(user, '@')) != NULL) |
| 385 | *p = '\0'; |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 386 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 387 | authctxt = authctxt_new(); |
| 388 | authctxt->user = user; |
| 389 | authctxt->style = style; |
| 390 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 391 | /* Verify that the user is a valid user. */ |
| 392 | pw = getpwnam(user); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 393 | if (pw && allowed_user(pw)) { |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 394 | authctxt->valid = 1; |
| 395 | pw = pwcopy(pw); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 396 | } else { |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 397 | debug("do_authentication: illegal user %s", user); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 398 | pw = NULL; |
| 399 | } |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 400 | authctxt->pw = pw; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 401 | |
Ben Lindstrom | c1ba31f | 2001-02-15 03:14:11 +0000 | [diff] [blame] | 402 | setproctitle("%s", pw ? user : "unknown"); |
| 403 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 404 | #ifdef USE_PAM |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 405 | if (pw) |
Damien Miller | 22e22bf | 2001-01-19 15:46:38 +1100 | [diff] [blame] | 406 | start_pam(user); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 407 | #endif |
| 408 | |
| 409 | /* |
| 410 | * If we are not running as root, the user must have the same uid as |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 411 | * the server. (Unless you are running Windows) |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 412 | */ |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 413 | #ifndef HAVE_CYGWIN |
| 414 | if (getuid() != 0 && pw && pw->pw_uid != getuid()) |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 415 | packet_disconnect("Cannot change user when server not running as root."); |
Damien Miller | bac2d8a | 2000-09-05 16:13:06 +1100 | [diff] [blame] | 416 | #endif |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 417 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 418 | /* |
Kevin Steves | 12aaa04 | 2001-01-24 21:23:39 +0000 | [diff] [blame] | 419 | * Loop until the user has been authenticated or the connection is |
| 420 | * closed, do_authloop() returns only if authentication is successful |
| 421 | */ |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 422 | do_authloop(authctxt); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 423 | |
| 424 | /* The user has been authenticated and accepted. */ |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 425 | packet_start(SSH_SMSG_SUCCESS); |
| 426 | packet_send(); |
| 427 | packet_write_wait(); |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 428 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 429 | /* Perform session preparation. */ |
Ben Lindstrom | b31783d | 2001-03-22 02:02:12 +0000 | [diff] [blame] | 430 | do_authenticated(authctxt); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 431 | } |