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 | 556f931 | 2003-02-24 11:59:26 +1100 | [diff] [blame] | 13 | RCSID("$OpenBSD: auth1.c,v 1.47 2003/02/06 21:22:42 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" |
Damien Miller | c7ef63d | 2002-02-05 12:21:42 +1100 | [diff] [blame] | 25 | #include "channels.h" |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 26 | #include "session.h" |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 27 | #include "uidswap.h" |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 28 | #include "monitor_wrap.h" |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 29 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 30 | /* import */ |
| 31 | extern ServerOptions options; |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 32 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 33 | /* |
| 34 | * convert ssh auth msg type into description |
| 35 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 36 | static char * |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 37 | get_authname(int type) |
| 38 | { |
| 39 | static char buf[1024]; |
| 40 | switch (type) { |
| 41 | case SSH_CMSG_AUTH_PASSWORD: |
| 42 | return "password"; |
| 43 | case SSH_CMSG_AUTH_RSA: |
| 44 | return "rsa"; |
| 45 | case SSH_CMSG_AUTH_RHOSTS_RSA: |
| 46 | return "rhosts-rsa"; |
| 47 | case SSH_CMSG_AUTH_RHOSTS: |
| 48 | return "rhosts"; |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 49 | case SSH_CMSG_AUTH_TIS: |
| 50 | case SSH_CMSG_AUTH_TIS_RESPONSE: |
| 51 | return "challenge-response"; |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 52 | #if defined(KRB4) || defined(KRB5) |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 53 | case SSH_CMSG_AUTH_KERBEROS: |
| 54 | return "kerberos"; |
| 55 | #endif |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 56 | } |
| 57 | snprintf(buf, sizeof buf, "bad-auth-msg-%d", type); |
| 58 | return buf; |
| 59 | } |
| 60 | |
| 61 | /* |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 62 | * read packets, try to authenticate the user and |
| 63 | * return only if authentication is successful |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 64 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 65 | static void |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 66 | do_authloop(Authctxt *authctxt) |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 67 | { |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 68 | int authenticated = 0; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 69 | u_int bits; |
Damien Miller | da75516 | 2002-01-22 23:09:22 +1100 | [diff] [blame] | 70 | Key *client_host_key; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 71 | BIGNUM *n; |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 72 | char *client_user, *password; |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 73 | char info[1024]; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 74 | u_int dlen; |
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 | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 87 | PRIVSEP(auth_password(authctxt, ""))) { |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 88 | auth_log(authctxt, 1, "without authentication", ""); |
| 89 | return; |
| 90 | } |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 91 | |
| 92 | /* Indicate that authentication is needed. */ |
| 93 | packet_start(SSH_SMSG_FAILURE); |
| 94 | packet_send(); |
| 95 | packet_write_wait(); |
| 96 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 97 | client_user = NULL; |
| 98 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 99 | for (;;) { |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 100 | /* default to fail */ |
| 101 | authenticated = 0; |
| 102 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 103 | info[0] = '\0'; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 104 | |
| 105 | /* Get a packet from the client. */ |
Damien Miller | dff5099 | 2002-01-22 23:16:32 +1100 | [diff] [blame] | 106 | type = packet_read(); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 107 | |
| 108 | /* Process the packet. */ |
| 109 | switch (type) { |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 110 | |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 111 | #if defined(KRB4) || defined(KRB5) |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 112 | case SSH_CMSG_AUTH_KERBEROS: |
| 113 | if (!options.kerberos_authentication) { |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 114 | verbose("Kerberos authentication disabled."); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 115 | } else { |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 116 | char *kdata = packet_get_string(&dlen); |
Damien Miller | 48b03fc | 2002-01-22 23:11:40 +1100 | [diff] [blame] | 117 | packet_check_eom(); |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 118 | |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 119 | if (kdata[0] == 4) { /* KRB_PROT_VERSION */ |
| 120 | #ifdef KRB4 |
Damien Miller | d94e549 | 2002-09-27 13:25:58 +1000 | [diff] [blame] | 121 | KTEXT_ST tkt, reply; |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 122 | tkt.length = dlen; |
| 123 | if (tkt.length < MAX_KTXT_LEN) |
| 124 | memcpy(tkt.dat, kdata, tkt.length); |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 125 | |
Damien Miller | d94e549 | 2002-09-27 13:25:58 +1000 | [diff] [blame] | 126 | if (PRIVSEP(auth_krb4(authctxt, &tkt, |
| 127 | &client_user, &reply))) { |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 128 | authenticated = 1; |
| 129 | snprintf(info, sizeof(info), |
| 130 | " tktuser %.100s", |
| 131 | client_user); |
Damien Miller | d94e549 | 2002-09-27 13:25:58 +1000 | [diff] [blame] | 132 | |
| 133 | packet_start( |
| 134 | SSH_SMSG_AUTH_KERBEROS_RESPONSE); |
| 135 | packet_put_string((char *) |
| 136 | reply.dat, reply.length); |
| 137 | packet_send(); |
| 138 | packet_write_wait(); |
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 |
Damien Miller | 25162f2 | 2002-09-12 09:47:29 +1000 | [diff] [blame] | 143 | krb5_data tkt, reply; |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 144 | tkt.length = dlen; |
| 145 | tkt.data = kdata; |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 146 | |
Damien Miller | 25162f2 | 2002-09-12 09:47:29 +1000 | [diff] [blame] | 147 | if (PRIVSEP(auth_krb5(authctxt, &tkt, |
| 148 | &client_user, &reply))) { |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 149 | authenticated = 1; |
| 150 | snprintf(info, sizeof(info), |
| 151 | " tktuser %.100s", |
| 152 | client_user); |
Ben Lindstrom | 93576d9 | 2002-12-23 02:06:19 +0000 | [diff] [blame] | 153 | |
Damien Miller | 25162f2 | 2002-09-12 09:47:29 +1000 | [diff] [blame] | 154 | /* Send response to client */ |
| 155 | packet_start( |
| 156 | SSH_SMSG_AUTH_KERBEROS_RESPONSE); |
| 157 | packet_put_string((char *) |
| 158 | reply.data, reply.length); |
| 159 | packet_send(); |
| 160 | packet_write_wait(); |
| 161 | |
| 162 | if (reply.length) |
| 163 | xfree(reply.data); |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 164 | } |
| 165 | #endif /* KRB5 */ |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 166 | } |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 167 | xfree(kdata); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 168 | } |
| 169 | break; |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 170 | #endif /* KRB4 || KRB5 */ |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 171 | |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 172 | #if defined(AFS) || defined(KRB5) |
| 173 | /* XXX - punt on backward compatibility here. */ |
| 174 | case SSH_CMSG_HAVE_KERBEROS_TGT: |
| 175 | packet_send_debug("Kerberos TGT passing disabled before authentication."); |
| 176 | break; |
| 177 | #ifdef AFS |
| 178 | case SSH_CMSG_HAVE_AFS_TOKEN: |
| 179 | packet_send_debug("AFS token passing disabled before authentication."); |
| 180 | break; |
| 181 | #endif /* AFS */ |
| 182 | #endif /* AFS || KRB5 */ |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 183 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 184 | case SSH_CMSG_AUTH_RHOSTS: |
| 185 | if (!options.rhosts_authentication) { |
| 186 | verbose("Rhosts authentication disabled."); |
| 187 | break; |
| 188 | } |
| 189 | /* |
| 190 | * Get client user name. Note that we just have to |
| 191 | * trust the client; this is one reason why rhosts |
| 192 | * authentication is insecure. (Another is |
| 193 | * IP-spoofing on a local network.) |
| 194 | */ |
| 195 | client_user = packet_get_string(&ulen); |
Damien Miller | 48b03fc | 2002-01-22 23:11:40 +1100 | [diff] [blame] | 196 | packet_check_eom(); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 197 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 198 | /* Try to authenticate using /etc/hosts.equiv and .rhosts. */ |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 199 | authenticated = auth_rhosts(pw, client_user); |
| 200 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 201 | snprintf(info, sizeof info, " ruser %.100s", client_user); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 202 | break; |
| 203 | |
| 204 | case SSH_CMSG_AUTH_RHOSTS_RSA: |
| 205 | if (!options.rhosts_rsa_authentication) { |
| 206 | verbose("Rhosts with RSA authentication disabled."); |
| 207 | break; |
| 208 | } |
| 209 | /* |
| 210 | * Get client user name. Note that we just have to |
| 211 | * trust the client; root on the client machine can |
| 212 | * claim to be any user. |
| 213 | */ |
| 214 | client_user = packet_get_string(&ulen); |
| 215 | |
| 216 | /* Get the client host key. */ |
Damien Miller | da75516 | 2002-01-22 23:09:22 +1100 | [diff] [blame] | 217 | client_host_key = key_new(KEY_RSA1); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 218 | bits = packet_get_int(); |
Damien Miller | d432ccf | 2002-01-22 23:14:44 +1100 | [diff] [blame] | 219 | packet_get_bignum(client_host_key->rsa->e); |
| 220 | packet_get_bignum(client_host_key->rsa->n); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 221 | |
Damien Miller | da75516 | 2002-01-22 23:09:22 +1100 | [diff] [blame] | 222 | if (bits != BN_num_bits(client_host_key->rsa->n)) |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 223 | verbose("Warning: keysize mismatch for client_host_key: " |
Damien Miller | da75516 | 2002-01-22 23:09:22 +1100 | [diff] [blame] | 224 | "actual %d, announced %d", |
Ben Lindstrom | cb72e4f | 2002-06-21 00:41:51 +0000 | [diff] [blame] | 225 | BN_num_bits(client_host_key->rsa->n), bits); |
Damien Miller | 48b03fc | 2002-01-22 23:11:40 +1100 | [diff] [blame] | 226 | packet_check_eom(); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 227 | |
Damien Miller | da75516 | 2002-01-22 23:09:22 +1100 | [diff] [blame] | 228 | authenticated = auth_rhosts_rsa(pw, client_user, |
Damien Miller | d221ca6 | 2002-01-22 23:11:00 +1100 | [diff] [blame] | 229 | client_host_key); |
Damien Miller | da75516 | 2002-01-22 23:09:22 +1100 | [diff] [blame] | 230 | key_free(client_host_key); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 231 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 232 | snprintf(info, sizeof info, " ruser %.100s", client_user); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 233 | break; |
| 234 | |
| 235 | case SSH_CMSG_AUTH_RSA: |
| 236 | if (!options.rsa_authentication) { |
| 237 | verbose("RSA authentication disabled."); |
| 238 | break; |
| 239 | } |
| 240 | /* RSA authentication requested. */ |
Damien Miller | da75516 | 2002-01-22 23:09:22 +1100 | [diff] [blame] | 241 | if ((n = BN_new()) == NULL) |
| 242 | fatal("do_authloop: BN_new failed"); |
Damien Miller | d432ccf | 2002-01-22 23:14:44 +1100 | [diff] [blame] | 243 | packet_get_bignum(n); |
Damien Miller | 48b03fc | 2002-01-22 23:11:40 +1100 | [diff] [blame] | 244 | packet_check_eom(); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 245 | authenticated = auth_rsa(pw, n); |
| 246 | BN_clear_free(n); |
| 247 | break; |
| 248 | |
| 249 | case SSH_CMSG_AUTH_PASSWORD: |
| 250 | if (!options.password_authentication) { |
| 251 | verbose("Password authentication disabled."); |
| 252 | break; |
| 253 | } |
| 254 | /* |
| 255 | * Read user password. It is in plain text, but was |
| 256 | * transmitted over the encrypted channel so it is |
| 257 | * not visible to an outside observer. |
| 258 | */ |
| 259 | password = packet_get_string(&dlen); |
Damien Miller | 48b03fc | 2002-01-22 23:11:40 +1100 | [diff] [blame] | 260 | packet_check_eom(); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 261 | |
Kevin Steves | 12aaa04 | 2001-01-24 21:23:39 +0000 | [diff] [blame] | 262 | /* Try authentication with the password. */ |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 263 | authenticated = PRIVSEP(auth_password(authctxt, password)); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 264 | |
| 265 | memset(password, 0, strlen(password)); |
| 266 | xfree(password); |
| 267 | break; |
| 268 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 269 | case SSH_CMSG_AUTH_TIS: |
| 270 | debug("rcvd SSH_CMSG_AUTH_TIS"); |
Ben Lindstrom | 551ea37 | 2001-06-05 18:56:16 +0000 | [diff] [blame] | 271 | if (options.challenge_response_authentication == 1) { |
| 272 | char *challenge = get_challenge(authctxt); |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 273 | if (challenge != NULL) { |
| 274 | debug("sending challenge '%s'", challenge); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 275 | packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE); |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 276 | packet_put_cstring(challenge); |
Ben Lindstrom | 551ea37 | 2001-06-05 18:56:16 +0000 | [diff] [blame] | 277 | xfree(challenge); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 278 | packet_send(); |
| 279 | packet_write_wait(); |
| 280 | continue; |
| 281 | } |
| 282 | } |
| 283 | break; |
| 284 | case SSH_CMSG_AUTH_TIS_RESPONSE: |
| 285 | debug("rcvd SSH_CMSG_AUTH_TIS_RESPONSE"); |
Ben Lindstrom | 551ea37 | 2001-06-05 18:56:16 +0000 | [diff] [blame] | 286 | if (options.challenge_response_authentication == 1) { |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 287 | char *response = packet_get_string(&dlen); |
Damien Miller | 48b03fc | 2002-01-22 23:11:40 +1100 | [diff] [blame] | 288 | packet_check_eom(); |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 289 | authenticated = verify_response(authctxt, response); |
| 290 | memset(response, 'r', dlen); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 291 | xfree(response); |
| 292 | } |
| 293 | break; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 294 | |
| 295 | default: |
| 296 | /* |
| 297 | * Any unknown messages will be ignored (and failure |
| 298 | * returned) during authentication. |
| 299 | */ |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 300 | logit("Unknown message during authentication: type %d", type); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 301 | break; |
| 302 | } |
Damien Miller | 60396b0 | 2001-02-18 17:01:00 +1100 | [diff] [blame] | 303 | #ifdef BSD_AUTH |
| 304 | if (authctxt->as) { |
| 305 | auth_close(authctxt->as); |
| 306 | authctxt->as = NULL; |
| 307 | } |
| 308 | #endif |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 309 | if (!authctxt->valid && authenticated) |
| 310 | fatal("INTERNAL ERROR: authenticated invalid user %s", |
| 311 | authctxt->user); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 312 | |
Tim Rice | 81ed518 | 2002-09-25 17:38:46 -0700 | [diff] [blame] | 313 | #ifdef _UNICOS |
| 314 | if (type == SSH_CMSG_AUTH_PASSWORD && !authenticated) |
| 315 | cray_login_failure(authctxt->user, IA_UDBERR); |
| 316 | if (authenticated && cray_access_denied(authctxt->user)) { |
| 317 | authenticated = 0; |
| 318 | fatal("Access denied for user %s.",authctxt->user); |
| 319 | } |
| 320 | #endif /* _UNICOS */ |
| 321 | |
Kevin Steves | ef4eea9 | 2001-02-05 12:42:17 +0000 | [diff] [blame] | 322 | #ifdef HAVE_CYGWIN |
| 323 | if (authenticated && |
Damien Miller | 0dea79d | 2001-12-29 14:08:28 +1100 | [diff] [blame] | 324 | !check_nt_auth(type == SSH_CMSG_AUTH_PASSWORD, pw)) { |
Damien Miller | bac2d8a | 2000-09-05 16:13:06 +1100 | [diff] [blame] | 325 | packet_disconnect("Authentication rejected for uid %d.", |
Damien Miller | 0dea79d | 2001-12-29 14:08:28 +1100 | [diff] [blame] | 326 | pw == NULL ? -1 : pw->pw_uid); |
Damien Miller | bac2d8a | 2000-09-05 16:13:06 +1100 | [diff] [blame] | 327 | authenticated = 0; |
| 328 | } |
Ben Lindstrom | 5dc8150 | 2001-01-19 06:10:29 +0000 | [diff] [blame] | 329 | #else |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 330 | /* Special handling for root */ |
Damien Miller | 556f931 | 2003-02-24 11:59:26 +1100 | [diff] [blame] | 331 | if (authenticated && authctxt->pw->pw_uid == 0 && |
Ben Lindstrom | d8a9021 | 2001-02-15 03:08:27 +0000 | [diff] [blame] | 332 | !auth_root_allowed(get_authname(type))) |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 333 | authenticated = 0; |
Ben Lindstrom | 5dc8150 | 2001-01-19 06:10:29 +0000 | [diff] [blame] | 334 | #endif |
Kevin Steves | ef4eea9 | 2001-02-05 12:42:17 +0000 | [diff] [blame] | 335 | #ifdef USE_PAM |
Damien Miller | 7941855 | 2002-04-23 20:28:48 +1000 | [diff] [blame] | 336 | if (!use_privsep && authenticated && |
| 337 | !do_pam_account(pw->pw_name, client_user)) |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 338 | authenticated = 0; |
| 339 | #endif |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 340 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 341 | /* Log before sending the reply */ |
| 342 | auth_log(authctxt, authenticated, get_authname(type), info); |
| 343 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 344 | if (client_user != NULL) { |
| 345 | xfree(client_user); |
| 346 | client_user = NULL; |
| 347 | } |
| 348 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 349 | if (authenticated) |
| 350 | return; |
| 351 | |
Ben Lindstrom | 683036e | 2003-04-27 18:41:30 +0000 | [diff] [blame^] | 352 | if (authctxt->failures++ > AUTH_FAIL_MAX) |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 353 | packet_disconnect(AUTH_FAIL_MSG, authctxt->user); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 354 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 355 | packet_start(SSH_SMSG_FAILURE); |
| 356 | packet_send(); |
| 357 | packet_write_wait(); |
| 358 | } |
| 359 | } |
| 360 | |
| 361 | /* |
| 362 | * Performs authentication of an incoming connection. Session key has already |
| 363 | * been exchanged and encryption is enabled. |
| 364 | */ |
Ben Lindstrom | 73ab9ba | 2002-03-22 01:27:35 +0000 | [diff] [blame] | 365 | Authctxt * |
Ben Lindstrom | 3c36bb2 | 2001-12-06 17:55:26 +0000 | [diff] [blame] | 366 | do_authentication(void) |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 367 | { |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 368 | Authctxt *authctxt; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 369 | u_int ulen; |
Ben Lindstrom | c822638 | 2002-04-10 16:22:09 +0000 | [diff] [blame] | 370 | char *user, *style = NULL; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 371 | |
| 372 | /* Get the name of the user that we wish to log in as. */ |
Damien Miller | dff5099 | 2002-01-22 23:16:32 +1100 | [diff] [blame] | 373 | packet_read_expect(SSH_CMSG_USER); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 374 | |
| 375 | /* Get the user name. */ |
| 376 | user = packet_get_string(&ulen); |
Damien Miller | 48b03fc | 2002-01-22 23:11:40 +1100 | [diff] [blame] | 377 | packet_check_eom(); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 378 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 379 | if ((style = strchr(user, ':')) != NULL) |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 380 | *style++ = '\0'; |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 381 | |
Ben Lindstrom | c822638 | 2002-04-10 16:22:09 +0000 | [diff] [blame] | 382 | #ifdef KRB5 |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 383 | /* XXX - SSH.com Kerberos v5 braindeath. */ |
Ben Lindstrom | c822638 | 2002-04-10 16:22:09 +0000 | [diff] [blame] | 384 | if ((datafellows & SSH_BUG_K5USER) && |
| 385 | options.kerberos_authentication) { |
| 386 | char *p; |
| 387 | if ((p = strchr(user, '@')) != NULL) |
| 388 | *p = '\0'; |
| 389 | } |
| 390 | #endif |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 391 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 392 | authctxt = authctxt_new(); |
| 393 | authctxt->user = user; |
| 394 | authctxt->style = style; |
| 395 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 396 | /* Verify that the user is a valid user. */ |
Ben Lindstrom | 7ebb635 | 2002-03-22 03:04:08 +0000 | [diff] [blame] | 397 | if ((authctxt->pw = PRIVSEP(getpwnamallow(user))) != NULL) |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 398 | authctxt->valid = 1; |
Ben Lindstrom | 7ebb635 | 2002-03-22 03:04:08 +0000 | [diff] [blame] | 399 | else |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 400 | debug("do_authentication: illegal user %s", user); |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 401 | |
Ben Lindstrom | 7ebb635 | 2002-03-22 03:04:08 +0000 | [diff] [blame] | 402 | setproctitle("%s%s", authctxt->pw ? user : "unknown", |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 403 | use_privsep ? " [net]" : ""); |
Ben Lindstrom | c1ba31f | 2001-02-15 03:14:11 +0000 | [diff] [blame] | 404 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 405 | #ifdef USE_PAM |
Damien Miller | 7941855 | 2002-04-23 20:28:48 +1000 | [diff] [blame] | 406 | PRIVSEP(start_pam(authctxt->pw == NULL ? "NOUSER" : 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 |
Ben Lindstrom | 7ebb635 | 2002-03-22 03:04:08 +0000 | [diff] [blame] | 414 | if (!use_privsep && getuid() != 0 && authctxt->pw && |
| 415 | authctxt->pw->pw_uid != getuid()) |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 416 | packet_disconnect("Cannot change user when server not running as root."); |
Damien Miller | bac2d8a | 2000-09-05 16:13:06 +1100 | [diff] [blame] | 417 | #endif |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 418 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 419 | /* |
Kevin Steves | 12aaa04 | 2001-01-24 21:23:39 +0000 | [diff] [blame] | 420 | * Loop until the user has been authenticated or the connection is |
| 421 | * closed, do_authloop() returns only if authentication is successful |
| 422 | */ |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 423 | do_authloop(authctxt); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 424 | |
| 425 | /* The user has been authenticated and accepted. */ |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 426 | packet_start(SSH_SMSG_SUCCESS); |
| 427 | packet_send(); |
| 428 | packet_write_wait(); |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 429 | |
Ben Lindstrom | 73ab9ba | 2002-03-22 01:27:35 +0000 | [diff] [blame] | 430 | return (authctxt); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 431 | } |