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 | 25162f2 | 2002-09-12 09:47:29 +1000 | [diff] [blame^] | 13 | RCSID("$OpenBSD: auth1.c,v 1.43 2002/09/09 06:48:06 itojun 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 |
| 121 | KTEXT_ST tkt; |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 122 | |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 123 | tkt.length = dlen; |
| 124 | if (tkt.length < MAX_KTXT_LEN) |
| 125 | memcpy(tkt.dat, kdata, tkt.length); |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 126 | |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 127 | if (auth_krb4(authctxt, &tkt, &client_user)) { |
| 128 | authenticated = 1; |
| 129 | snprintf(info, sizeof(info), |
| 130 | " tktuser %.100s", |
| 131 | client_user); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 132 | } |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 133 | #endif /* KRB4 */ |
| 134 | } else { |
| 135 | #ifdef KRB5 |
Damien Miller | 25162f2 | 2002-09-12 09:47:29 +1000 | [diff] [blame^] | 136 | krb5_data tkt, reply; |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 137 | tkt.length = dlen; |
| 138 | tkt.data = kdata; |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 139 | |
Damien Miller | 25162f2 | 2002-09-12 09:47:29 +1000 | [diff] [blame^] | 140 | if (PRIVSEP(auth_krb5(authctxt, &tkt, |
| 141 | &client_user, &reply))) { |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 142 | authenticated = 1; |
| 143 | snprintf(info, sizeof(info), |
| 144 | " tktuser %.100s", |
| 145 | client_user); |
Damien Miller | 25162f2 | 2002-09-12 09:47:29 +1000 | [diff] [blame^] | 146 | |
| 147 | /* Send response to client */ |
| 148 | packet_start( |
| 149 | SSH_SMSG_AUTH_KERBEROS_RESPONSE); |
| 150 | packet_put_string((char *) |
| 151 | reply.data, reply.length); |
| 152 | packet_send(); |
| 153 | packet_write_wait(); |
| 154 | |
| 155 | if (reply.length) |
| 156 | xfree(reply.data); |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 157 | } |
| 158 | #endif /* KRB5 */ |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 159 | } |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 160 | xfree(kdata); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 161 | } |
| 162 | break; |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 163 | #endif /* KRB4 || KRB5 */ |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 164 | |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 165 | #if defined(AFS) || defined(KRB5) |
| 166 | /* XXX - punt on backward compatibility here. */ |
| 167 | case SSH_CMSG_HAVE_KERBEROS_TGT: |
| 168 | packet_send_debug("Kerberos TGT passing disabled before authentication."); |
| 169 | break; |
| 170 | #ifdef AFS |
| 171 | case SSH_CMSG_HAVE_AFS_TOKEN: |
| 172 | packet_send_debug("AFS token passing disabled before authentication."); |
| 173 | break; |
| 174 | #endif /* AFS */ |
| 175 | #endif /* AFS || KRB5 */ |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 176 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 177 | case SSH_CMSG_AUTH_RHOSTS: |
| 178 | if (!options.rhosts_authentication) { |
| 179 | verbose("Rhosts authentication disabled."); |
| 180 | break; |
| 181 | } |
| 182 | /* |
| 183 | * Get client user name. Note that we just have to |
| 184 | * trust the client; this is one reason why rhosts |
| 185 | * authentication is insecure. (Another is |
| 186 | * IP-spoofing on a local network.) |
| 187 | */ |
| 188 | client_user = packet_get_string(&ulen); |
Damien Miller | 48b03fc | 2002-01-22 23:11:40 +1100 | [diff] [blame] | 189 | packet_check_eom(); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 190 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 191 | /* Try to authenticate using /etc/hosts.equiv and .rhosts. */ |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 192 | authenticated = auth_rhosts(pw, client_user); |
| 193 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 194 | snprintf(info, sizeof info, " ruser %.100s", client_user); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 195 | break; |
| 196 | |
| 197 | case SSH_CMSG_AUTH_RHOSTS_RSA: |
| 198 | if (!options.rhosts_rsa_authentication) { |
| 199 | verbose("Rhosts with RSA authentication disabled."); |
| 200 | break; |
| 201 | } |
| 202 | /* |
| 203 | * Get client user name. Note that we just have to |
| 204 | * trust the client; root on the client machine can |
| 205 | * claim to be any user. |
| 206 | */ |
| 207 | client_user = packet_get_string(&ulen); |
| 208 | |
| 209 | /* Get the client host key. */ |
Damien Miller | da75516 | 2002-01-22 23:09:22 +1100 | [diff] [blame] | 210 | client_host_key = key_new(KEY_RSA1); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 211 | bits = packet_get_int(); |
Damien Miller | d432ccf | 2002-01-22 23:14:44 +1100 | [diff] [blame] | 212 | packet_get_bignum(client_host_key->rsa->e); |
| 213 | packet_get_bignum(client_host_key->rsa->n); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 214 | |
Damien Miller | da75516 | 2002-01-22 23:09:22 +1100 | [diff] [blame] | 215 | if (bits != BN_num_bits(client_host_key->rsa->n)) |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 216 | verbose("Warning: keysize mismatch for client_host_key: " |
Damien Miller | da75516 | 2002-01-22 23:09:22 +1100 | [diff] [blame] | 217 | "actual %d, announced %d", |
Ben Lindstrom | cb72e4f | 2002-06-21 00:41:51 +0000 | [diff] [blame] | 218 | BN_num_bits(client_host_key->rsa->n), bits); |
Damien Miller | 48b03fc | 2002-01-22 23:11:40 +1100 | [diff] [blame] | 219 | packet_check_eom(); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 220 | |
Damien Miller | da75516 | 2002-01-22 23:09:22 +1100 | [diff] [blame] | 221 | authenticated = auth_rhosts_rsa(pw, client_user, |
Damien Miller | d221ca6 | 2002-01-22 23:11:00 +1100 | [diff] [blame] | 222 | client_host_key); |
Damien Miller | da75516 | 2002-01-22 23:09:22 +1100 | [diff] [blame] | 223 | key_free(client_host_key); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 224 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 225 | snprintf(info, sizeof info, " ruser %.100s", client_user); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 226 | break; |
| 227 | |
| 228 | case SSH_CMSG_AUTH_RSA: |
| 229 | if (!options.rsa_authentication) { |
| 230 | verbose("RSA authentication disabled."); |
| 231 | break; |
| 232 | } |
| 233 | /* RSA authentication requested. */ |
Damien Miller | da75516 | 2002-01-22 23:09:22 +1100 | [diff] [blame] | 234 | if ((n = BN_new()) == NULL) |
| 235 | fatal("do_authloop: BN_new failed"); |
Damien Miller | d432ccf | 2002-01-22 23:14:44 +1100 | [diff] [blame] | 236 | packet_get_bignum(n); |
Damien Miller | 48b03fc | 2002-01-22 23:11:40 +1100 | [diff] [blame] | 237 | packet_check_eom(); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 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); |
Damien Miller | 48b03fc | 2002-01-22 23:11:40 +1100 | [diff] [blame] | 253 | packet_check_eom(); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 254 | |
Kevin Steves | 12aaa04 | 2001-01-24 21:23:39 +0000 | [diff] [blame] | 255 | /* Try authentication with the password. */ |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 256 | authenticated = PRIVSEP(auth_password(authctxt, password)); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 257 | |
| 258 | memset(password, 0, strlen(password)); |
| 259 | xfree(password); |
| 260 | break; |
| 261 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 262 | case SSH_CMSG_AUTH_TIS: |
| 263 | debug("rcvd SSH_CMSG_AUTH_TIS"); |
Ben Lindstrom | 551ea37 | 2001-06-05 18:56:16 +0000 | [diff] [blame] | 264 | if (options.challenge_response_authentication == 1) { |
| 265 | char *challenge = get_challenge(authctxt); |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 266 | if (challenge != NULL) { |
| 267 | debug("sending challenge '%s'", challenge); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 268 | packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE); |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 269 | packet_put_cstring(challenge); |
Ben Lindstrom | 551ea37 | 2001-06-05 18:56:16 +0000 | [diff] [blame] | 270 | xfree(challenge); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 271 | packet_send(); |
| 272 | packet_write_wait(); |
| 273 | continue; |
| 274 | } |
| 275 | } |
| 276 | break; |
| 277 | case SSH_CMSG_AUTH_TIS_RESPONSE: |
| 278 | debug("rcvd SSH_CMSG_AUTH_TIS_RESPONSE"); |
Ben Lindstrom | 551ea37 | 2001-06-05 18:56:16 +0000 | [diff] [blame] | 279 | if (options.challenge_response_authentication == 1) { |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 280 | char *response = packet_get_string(&dlen); |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 281 | debug("got response '%s'", response); |
Damien Miller | 48b03fc | 2002-01-22 23:11:40 +1100 | [diff] [blame] | 282 | packet_check_eom(); |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 283 | authenticated = verify_response(authctxt, response); |
| 284 | memset(response, 'r', dlen); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 285 | xfree(response); |
| 286 | } |
| 287 | break; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 288 | |
| 289 | default: |
| 290 | /* |
| 291 | * Any unknown messages will be ignored (and failure |
| 292 | * returned) during authentication. |
| 293 | */ |
| 294 | log("Unknown message during authentication: type %d", type); |
| 295 | break; |
| 296 | } |
Damien Miller | 60396b0 | 2001-02-18 17:01:00 +1100 | [diff] [blame] | 297 | #ifdef BSD_AUTH |
| 298 | if (authctxt->as) { |
| 299 | auth_close(authctxt->as); |
| 300 | authctxt->as = NULL; |
| 301 | } |
| 302 | #endif |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 303 | if (!authctxt->valid && authenticated) |
| 304 | fatal("INTERNAL ERROR: authenticated invalid user %s", |
| 305 | authctxt->user); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 306 | |
Kevin Steves | ef4eea9 | 2001-02-05 12:42:17 +0000 | [diff] [blame] | 307 | #ifdef HAVE_CYGWIN |
| 308 | if (authenticated && |
Damien Miller | 0dea79d | 2001-12-29 14:08:28 +1100 | [diff] [blame] | 309 | !check_nt_auth(type == SSH_CMSG_AUTH_PASSWORD, pw)) { |
Damien Miller | bac2d8a | 2000-09-05 16:13:06 +1100 | [diff] [blame] | 310 | packet_disconnect("Authentication rejected for uid %d.", |
Damien Miller | 0dea79d | 2001-12-29 14:08:28 +1100 | [diff] [blame] | 311 | pw == NULL ? -1 : pw->pw_uid); |
Damien Miller | bac2d8a | 2000-09-05 16:13:06 +1100 | [diff] [blame] | 312 | authenticated = 0; |
| 313 | } |
Ben Lindstrom | 5dc8150 | 2001-01-19 06:10:29 +0000 | [diff] [blame] | 314 | #else |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 315 | /* Special handling for root */ |
Damien Miller | de6f2de | 2002-09-04 16:37:26 +1000 | [diff] [blame] | 316 | if (!use_privsep && |
| 317 | authenticated && authctxt->pw->pw_uid == 0 && |
Ben Lindstrom | d8a9021 | 2001-02-15 03:08:27 +0000 | [diff] [blame] | 318 | !auth_root_allowed(get_authname(type))) |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 319 | authenticated = 0; |
Ben Lindstrom | 5dc8150 | 2001-01-19 06:10:29 +0000 | [diff] [blame] | 320 | #endif |
Kevin Steves | ef4eea9 | 2001-02-05 12:42:17 +0000 | [diff] [blame] | 321 | #ifdef USE_PAM |
Damien Miller | 7941855 | 2002-04-23 20:28:48 +1000 | [diff] [blame] | 322 | if (!use_privsep && authenticated && |
| 323 | !do_pam_account(pw->pw_name, client_user)) |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 324 | authenticated = 0; |
| 325 | #endif |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 326 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 327 | /* Log before sending the reply */ |
| 328 | auth_log(authctxt, authenticated, get_authname(type), info); |
| 329 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 330 | if (client_user != NULL) { |
| 331 | xfree(client_user); |
| 332 | client_user = NULL; |
| 333 | } |
| 334 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 335 | if (authenticated) |
| 336 | return; |
| 337 | |
Kevin Steves | 12aaa04 | 2001-01-24 21:23:39 +0000 | [diff] [blame] | 338 | if (authctxt->failures++ > AUTH_FAIL_MAX) { |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 339 | packet_disconnect(AUTH_FAIL_MSG, authctxt->user); |
Damien Miller | d2c208a | 2000-05-17 22:00:02 +1000 | [diff] [blame] | 340 | } |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 341 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 342 | packet_start(SSH_SMSG_FAILURE); |
| 343 | packet_send(); |
| 344 | packet_write_wait(); |
| 345 | } |
| 346 | } |
| 347 | |
| 348 | /* |
| 349 | * Performs authentication of an incoming connection. Session key has already |
| 350 | * been exchanged and encryption is enabled. |
| 351 | */ |
Ben Lindstrom | 73ab9ba | 2002-03-22 01:27:35 +0000 | [diff] [blame] | 352 | Authctxt * |
Ben Lindstrom | 3c36bb2 | 2001-12-06 17:55:26 +0000 | [diff] [blame] | 353 | do_authentication(void) |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 354 | { |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 355 | Authctxt *authctxt; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 356 | u_int ulen; |
Ben Lindstrom | c822638 | 2002-04-10 16:22:09 +0000 | [diff] [blame] | 357 | char *user, *style = NULL; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 358 | |
| 359 | /* 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] | 360 | packet_read_expect(SSH_CMSG_USER); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 361 | |
| 362 | /* Get the user name. */ |
| 363 | user = packet_get_string(&ulen); |
Damien Miller | 48b03fc | 2002-01-22 23:11:40 +1100 | [diff] [blame] | 364 | packet_check_eom(); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 365 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 366 | if ((style = strchr(user, ':')) != NULL) |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 367 | *style++ = '\0'; |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 368 | |
Ben Lindstrom | c822638 | 2002-04-10 16:22:09 +0000 | [diff] [blame] | 369 | #ifdef KRB5 |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 370 | /* XXX - SSH.com Kerberos v5 braindeath. */ |
Ben Lindstrom | c822638 | 2002-04-10 16:22:09 +0000 | [diff] [blame] | 371 | if ((datafellows & SSH_BUG_K5USER) && |
| 372 | options.kerberos_authentication) { |
| 373 | char *p; |
| 374 | if ((p = strchr(user, '@')) != NULL) |
| 375 | *p = '\0'; |
| 376 | } |
| 377 | #endif |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 378 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 379 | authctxt = authctxt_new(); |
| 380 | authctxt->user = user; |
| 381 | authctxt->style = style; |
| 382 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 383 | /* Verify that the user is a valid user. */ |
Ben Lindstrom | 7ebb635 | 2002-03-22 03:04:08 +0000 | [diff] [blame] | 384 | if ((authctxt->pw = PRIVSEP(getpwnamallow(user))) != NULL) |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 385 | authctxt->valid = 1; |
Ben Lindstrom | 7ebb635 | 2002-03-22 03:04:08 +0000 | [diff] [blame] | 386 | else |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 387 | debug("do_authentication: illegal user %s", user); |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 388 | |
Ben Lindstrom | 7ebb635 | 2002-03-22 03:04:08 +0000 | [diff] [blame] | 389 | setproctitle("%s%s", authctxt->pw ? user : "unknown", |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 390 | use_privsep ? " [net]" : ""); |
Ben Lindstrom | c1ba31f | 2001-02-15 03:14:11 +0000 | [diff] [blame] | 391 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 392 | #ifdef USE_PAM |
Damien Miller | 7941855 | 2002-04-23 20:28:48 +1000 | [diff] [blame] | 393 | PRIVSEP(start_pam(authctxt->pw == NULL ? "NOUSER" : user)); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 394 | #endif |
| 395 | |
| 396 | /* |
| 397 | * 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] | 398 | * the server. (Unless you are running Windows) |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 399 | */ |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 400 | #ifndef HAVE_CYGWIN |
Ben Lindstrom | 7ebb635 | 2002-03-22 03:04:08 +0000 | [diff] [blame] | 401 | if (!use_privsep && getuid() != 0 && authctxt->pw && |
| 402 | authctxt->pw->pw_uid != getuid()) |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 403 | packet_disconnect("Cannot change user when server not running as root."); |
Damien Miller | bac2d8a | 2000-09-05 16:13:06 +1100 | [diff] [blame] | 404 | #endif |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 405 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 406 | /* |
Kevin Steves | 12aaa04 | 2001-01-24 21:23:39 +0000 | [diff] [blame] | 407 | * Loop until the user has been authenticated or the connection is |
| 408 | * closed, do_authloop() returns only if authentication is successful |
| 409 | */ |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 410 | do_authloop(authctxt); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 411 | |
| 412 | /* The user has been authenticated and accepted. */ |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 413 | packet_start(SSH_SMSG_SUCCESS); |
| 414 | packet_send(); |
| 415 | packet_write_wait(); |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 416 | |
Ben Lindstrom | 73ab9ba | 2002-03-22 01:27:35 +0000 | [diff] [blame] | 417 | return (authctxt); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 418 | } |