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 | 30d1f84 | 2004-07-21 20:48:53 +1000 | [diff] [blame] | 13 | RCSID("$OpenBSD: auth1.c,v 1.58 2004/07/21 10:33:31 djm 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" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 20 | #include "log.h" |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 21 | #include "servconf.h" |
| 22 | #include "compat.h" |
| 23 | #include "auth.h" |
Damien Miller | c7ef63d | 2002-02-05 12:21:42 +1100 | [diff] [blame] | 24 | #include "channels.h" |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 25 | #include "session.h" |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 26 | #include "uidswap.h" |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 27 | #include "monitor_wrap.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"; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 51 | } |
| 52 | snprintf(buf, sizeof buf, "bad-auth-msg-%d", type); |
| 53 | return buf; |
| 54 | } |
| 55 | |
| 56 | /* |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 57 | * read packets, try to authenticate the user and |
| 58 | * return only if authentication is successful |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 59 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 60 | static void |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 61 | do_authloop(Authctxt *authctxt) |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 62 | { |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 63 | int authenticated = 0; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 64 | u_int bits; |
Damien Miller | da75516 | 2002-01-22 23:09:22 +1100 | [diff] [blame] | 65 | Key *client_host_key; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 66 | BIGNUM *n; |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 67 | char *client_user, *password; |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 68 | char info[1024]; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 69 | u_int dlen; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 70 | u_int ulen; |
Damien Miller | 4f9f42a | 2003-05-10 19:28:02 +1000 | [diff] [blame] | 71 | int prev, type = 0; |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 72 | |
| 73 | debug("Attempting authentication for %s%.100s.", |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 74 | authctxt->valid ? "" : "illegal user ", authctxt->user); |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 75 | |
| 76 | /* If the user has no password, accept authentication immediately. */ |
| 77 | if (options.password_authentication && |
Darren Tucker | 6aaa58c | 2003-08-02 22:24:49 +1000 | [diff] [blame] | 78 | #ifdef KRB5 |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 79 | (!options.kerberos_authentication || options.kerberos_or_local_passwd) && |
| 80 | #endif |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 81 | PRIVSEP(auth_password(authctxt, ""))) { |
Darren Tucker | a8c73d3 | 2004-06-23 09:17:54 +1000 | [diff] [blame] | 82 | #ifdef USE_PAM |
| 83 | if (options.use_pam && (PRIVSEP(do_pam_account()))) |
| 84 | #endif |
| 85 | { |
| 86 | auth_log(authctxt, 1, "without authentication", ""); |
| 87 | return; |
| 88 | } |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 89 | } |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 90 | |
| 91 | /* Indicate that authentication is needed. */ |
| 92 | packet_start(SSH_SMSG_FAILURE); |
| 93 | packet_send(); |
| 94 | packet_write_wait(); |
| 95 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 96 | client_user = NULL; |
| 97 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 98 | for (;;) { |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 99 | /* default to fail */ |
| 100 | authenticated = 0; |
| 101 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 102 | info[0] = '\0'; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 103 | |
| 104 | /* Get a packet from the client. */ |
Damien Miller | 4f9f42a | 2003-05-10 19:28:02 +1000 | [diff] [blame] | 105 | prev = type; |
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 | |
Damien Miller | 4f9f42a | 2003-05-10 19:28:02 +1000 | [diff] [blame] | 108 | /* |
| 109 | * If we started challenge-response authentication but the |
| 110 | * next packet is not a response to our challenge, release |
| 111 | * the resources allocated by get_challenge() (which would |
| 112 | * normally have been released by verify_response() had we |
| 113 | * received such a response) |
| 114 | */ |
| 115 | if (prev == SSH_CMSG_AUTH_TIS && |
| 116 | type != SSH_CMSG_AUTH_TIS_RESPONSE) |
| 117 | abandon_challenge_response(authctxt); |
| 118 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 119 | /* Process the packet. */ |
| 120 | switch (type) { |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 121 | case SSH_CMSG_AUTH_RHOSTS_RSA: |
| 122 | if (!options.rhosts_rsa_authentication) { |
| 123 | verbose("Rhosts with RSA authentication disabled."); |
| 124 | break; |
| 125 | } |
| 126 | /* |
| 127 | * Get client user name. Note that we just have to |
| 128 | * trust the client; root on the client machine can |
| 129 | * claim to be any user. |
| 130 | */ |
| 131 | client_user = packet_get_string(&ulen); |
| 132 | |
| 133 | /* Get the client host key. */ |
Damien Miller | da75516 | 2002-01-22 23:09:22 +1100 | [diff] [blame] | 134 | client_host_key = key_new(KEY_RSA1); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 135 | bits = packet_get_int(); |
Damien Miller | d432ccf | 2002-01-22 23:14:44 +1100 | [diff] [blame] | 136 | packet_get_bignum(client_host_key->rsa->e); |
| 137 | packet_get_bignum(client_host_key->rsa->n); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 138 | |
Damien Miller | da75516 | 2002-01-22 23:09:22 +1100 | [diff] [blame] | 139 | if (bits != BN_num_bits(client_host_key->rsa->n)) |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 140 | verbose("Warning: keysize mismatch for client_host_key: " |
Damien Miller | da75516 | 2002-01-22 23:09:22 +1100 | [diff] [blame] | 141 | "actual %d, announced %d", |
Ben Lindstrom | cb72e4f | 2002-06-21 00:41:51 +0000 | [diff] [blame] | 142 | BN_num_bits(client_host_key->rsa->n), bits); |
Damien Miller | 48b03fc | 2002-01-22 23:11:40 +1100 | [diff] [blame] | 143 | packet_check_eom(); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 144 | |
Damien Miller | 3e3b514 | 2003-11-17 21:13:40 +1100 | [diff] [blame] | 145 | authenticated = auth_rhosts_rsa(authctxt, client_user, |
Damien Miller | d221ca6 | 2002-01-22 23:11:00 +1100 | [diff] [blame] | 146 | client_host_key); |
Damien Miller | da75516 | 2002-01-22 23:09:22 +1100 | [diff] [blame] | 147 | key_free(client_host_key); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 148 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 149 | snprintf(info, sizeof info, " ruser %.100s", client_user); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 150 | break; |
| 151 | |
| 152 | case SSH_CMSG_AUTH_RSA: |
| 153 | if (!options.rsa_authentication) { |
| 154 | verbose("RSA authentication disabled."); |
| 155 | break; |
| 156 | } |
| 157 | /* RSA authentication requested. */ |
Damien Miller | da75516 | 2002-01-22 23:09:22 +1100 | [diff] [blame] | 158 | if ((n = BN_new()) == NULL) |
| 159 | fatal("do_authloop: BN_new failed"); |
Damien Miller | d432ccf | 2002-01-22 23:14:44 +1100 | [diff] [blame] | 160 | packet_get_bignum(n); |
Damien Miller | 48b03fc | 2002-01-22 23:11:40 +1100 | [diff] [blame] | 161 | packet_check_eom(); |
Damien Miller | 3e3b514 | 2003-11-17 21:13:40 +1100 | [diff] [blame] | 162 | authenticated = auth_rsa(authctxt, n); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 163 | BN_clear_free(n); |
| 164 | break; |
| 165 | |
| 166 | case SSH_CMSG_AUTH_PASSWORD: |
| 167 | if (!options.password_authentication) { |
| 168 | verbose("Password authentication disabled."); |
| 169 | break; |
| 170 | } |
| 171 | /* |
| 172 | * Read user password. It is in plain text, but was |
| 173 | * transmitted over the encrypted channel so it is |
| 174 | * not visible to an outside observer. |
| 175 | */ |
| 176 | password = packet_get_string(&dlen); |
Damien Miller | 48b03fc | 2002-01-22 23:11:40 +1100 | [diff] [blame] | 177 | packet_check_eom(); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 178 | |
Kevin Steves | 12aaa04 | 2001-01-24 21:23:39 +0000 | [diff] [blame] | 179 | /* Try authentication with the password. */ |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 180 | authenticated = PRIVSEP(auth_password(authctxt, password)); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 181 | |
| 182 | memset(password, 0, strlen(password)); |
| 183 | xfree(password); |
| 184 | break; |
| 185 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 186 | case SSH_CMSG_AUTH_TIS: |
| 187 | debug("rcvd SSH_CMSG_AUTH_TIS"); |
Ben Lindstrom | 551ea37 | 2001-06-05 18:56:16 +0000 | [diff] [blame] | 188 | if (options.challenge_response_authentication == 1) { |
| 189 | char *challenge = get_challenge(authctxt); |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 190 | if (challenge != NULL) { |
| 191 | debug("sending challenge '%s'", challenge); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 192 | packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE); |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 193 | packet_put_cstring(challenge); |
Ben Lindstrom | 551ea37 | 2001-06-05 18:56:16 +0000 | [diff] [blame] | 194 | xfree(challenge); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 195 | packet_send(); |
| 196 | packet_write_wait(); |
| 197 | continue; |
| 198 | } |
| 199 | } |
| 200 | break; |
| 201 | case SSH_CMSG_AUTH_TIS_RESPONSE: |
| 202 | debug("rcvd SSH_CMSG_AUTH_TIS_RESPONSE"); |
Ben Lindstrom | 551ea37 | 2001-06-05 18:56:16 +0000 | [diff] [blame] | 203 | if (options.challenge_response_authentication == 1) { |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 204 | char *response = packet_get_string(&dlen); |
Damien Miller | 48b03fc | 2002-01-22 23:11:40 +1100 | [diff] [blame] | 205 | packet_check_eom(); |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 206 | authenticated = verify_response(authctxt, response); |
| 207 | memset(response, 'r', dlen); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 208 | xfree(response); |
| 209 | } |
| 210 | break; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 211 | |
| 212 | default: |
| 213 | /* |
| 214 | * Any unknown messages will be ignored (and failure |
| 215 | * returned) during authentication. |
| 216 | */ |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 217 | logit("Unknown message during authentication: type %d", type); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 218 | break; |
| 219 | } |
Damien Miller | 60396b0 | 2001-02-18 17:01:00 +1100 | [diff] [blame] | 220 | #ifdef BSD_AUTH |
| 221 | if (authctxt->as) { |
| 222 | auth_close(authctxt->as); |
| 223 | authctxt->as = NULL; |
| 224 | } |
| 225 | #endif |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 226 | if (!authctxt->valid && authenticated) |
| 227 | fatal("INTERNAL ERROR: authenticated invalid user %s", |
| 228 | authctxt->user); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 229 | |
Tim Rice | 81ed518 | 2002-09-25 17:38:46 -0700 | [diff] [blame] | 230 | #ifdef _UNICOS |
Tim Rice | 81ed518 | 2002-09-25 17:38:46 -0700 | [diff] [blame] | 231 | if (authenticated && cray_access_denied(authctxt->user)) { |
| 232 | authenticated = 0; |
| 233 | fatal("Access denied for user %s.",authctxt->user); |
| 234 | } |
| 235 | #endif /* _UNICOS */ |
| 236 | |
Kevin Steves | ef4eea9 | 2001-02-05 12:42:17 +0000 | [diff] [blame] | 237 | #ifdef HAVE_CYGWIN |
| 238 | if (authenticated && |
Ben Lindstrom | e35bf12 | 2004-06-22 03:37:11 +0000 | [diff] [blame] | 239 | !check_nt_auth(type == SSH_CMSG_AUTH_PASSWORD, |
| 240 | authctxt->pw)) { |
Damien Miller | bac2d8a | 2000-09-05 16:13:06 +1100 | [diff] [blame] | 241 | packet_disconnect("Authentication rejected for uid %d.", |
Ben Lindstrom | e35bf12 | 2004-06-22 03:37:11 +0000 | [diff] [blame] | 242 | authctxt->pw == NULL ? -1 : authctxt->pw->pw_uid); |
Damien Miller | bac2d8a | 2000-09-05 16:13:06 +1100 | [diff] [blame] | 243 | authenticated = 0; |
| 244 | } |
Ben Lindstrom | 5dc8150 | 2001-01-19 06:10:29 +0000 | [diff] [blame] | 245 | #else |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 246 | /* Special handling for root */ |
Damien Miller | 556f931 | 2003-02-24 11:59:26 +1100 | [diff] [blame] | 247 | if (authenticated && authctxt->pw->pw_uid == 0 && |
Ben Lindstrom | d8a9021 | 2001-02-15 03:08:27 +0000 | [diff] [blame] | 248 | !auth_root_allowed(get_authname(type))) |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 249 | authenticated = 0; |
Ben Lindstrom | 5dc8150 | 2001-01-19 06:10:29 +0000 | [diff] [blame] | 250 | #endif |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 251 | |
Damien Miller | 1f499fd | 2003-08-25 13:08:49 +1000 | [diff] [blame] | 252 | #ifdef USE_PAM |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 253 | if (options.use_pam && authenticated && |
Damien Miller | 1f499fd | 2003-08-25 13:08:49 +1000 | [diff] [blame] | 254 | !PRIVSEP(do_pam_account())) |
| 255 | authenticated = 0; |
| 256 | #endif |
| 257 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 258 | /* Log before sending the reply */ |
| 259 | auth_log(authctxt, authenticated, get_authname(type), info); |
| 260 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 261 | if (client_user != NULL) { |
| 262 | xfree(client_user); |
| 263 | client_user = NULL; |
| 264 | } |
| 265 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 266 | if (authenticated) |
| 267 | return; |
| 268 | |
Darren Tucker | 89413db | 2004-05-24 10:36:23 +1000 | [diff] [blame] | 269 | if (authctxt->failures++ > options.max_authtries) |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 270 | packet_disconnect(AUTH_FAIL_MSG, authctxt->user); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 271 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 272 | packet_start(SSH_SMSG_FAILURE); |
| 273 | packet_send(); |
| 274 | packet_write_wait(); |
| 275 | } |
| 276 | } |
| 277 | |
| 278 | /* |
| 279 | * Performs authentication of an incoming connection. Session key has already |
| 280 | * been exchanged and encryption is enabled. |
| 281 | */ |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 282 | void |
| 283 | do_authentication(Authctxt *authctxt) |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 284 | { |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 285 | u_int ulen; |
Ben Lindstrom | c822638 | 2002-04-10 16:22:09 +0000 | [diff] [blame] | 286 | char *user, *style = NULL; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 287 | |
| 288 | /* 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] | 289 | packet_read_expect(SSH_CMSG_USER); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 290 | |
| 291 | /* Get the user name. */ |
| 292 | user = packet_get_string(&ulen); |
Damien Miller | 48b03fc | 2002-01-22 23:11:40 +1100 | [diff] [blame] | 293 | packet_check_eom(); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 294 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 295 | if ((style = strchr(user, ':')) != NULL) |
Ben Lindstrom | ec95ed9 | 2001-07-04 04:21:14 +0000 | [diff] [blame] | 296 | *style++ = '\0'; |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 297 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 298 | authctxt->user = user; |
| 299 | authctxt->style = style; |
| 300 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 301 | /* Verify that the user is a valid user. */ |
Ben Lindstrom | 7ebb635 | 2002-03-22 03:04:08 +0000 | [diff] [blame] | 302 | if ((authctxt->pw = PRIVSEP(getpwnamallow(user))) != NULL) |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 303 | authctxt->valid = 1; |
Damien Miller | 856f0be | 2003-09-03 07:32:45 +1000 | [diff] [blame] | 304 | else { |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 305 | debug("do_authentication: illegal user %s", user); |
Damien Miller | 856f0be | 2003-09-03 07:32:45 +1000 | [diff] [blame] | 306 | authctxt->pw = fakepw(); |
| 307 | } |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 308 | |
Damien Miller | 30d1f84 | 2004-07-21 20:48:53 +1000 | [diff] [blame] | 309 | setproctitle("%s%s", authctxt->valid ? user : "unknown", |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 310 | use_privsep ? " [net]" : ""); |
Ben Lindstrom | c1ba31f | 2001-02-15 03:14:11 +0000 | [diff] [blame] | 311 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 312 | #ifdef USE_PAM |
Damien Miller | 4e448a3 | 2003-05-14 15:11:48 +1000 | [diff] [blame] | 313 | if (options.use_pam) |
Darren Tucker | dbf7a74 | 2004-03-08 23:04:06 +1100 | [diff] [blame] | 314 | PRIVSEP(start_pam(authctxt)); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 315 | #endif |
| 316 | |
| 317 | /* |
| 318 | * 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] | 319 | * the server. (Unless you are running Windows) |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 320 | */ |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 321 | #ifndef HAVE_CYGWIN |
Ben Lindstrom | 7ebb635 | 2002-03-22 03:04:08 +0000 | [diff] [blame] | 322 | if (!use_privsep && getuid() != 0 && authctxt->pw && |
| 323 | authctxt->pw->pw_uid != getuid()) |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 324 | packet_disconnect("Cannot change user when server not running as root."); |
Damien Miller | bac2d8a | 2000-09-05 16:13:06 +1100 | [diff] [blame] | 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 | /* |
Kevin Steves | 12aaa04 | 2001-01-24 21:23:39 +0000 | [diff] [blame] | 328 | * Loop until the user has been authenticated or the connection is |
| 329 | * closed, do_authloop() returns only if authentication is successful |
| 330 | */ |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 331 | do_authloop(authctxt); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 332 | |
| 333 | /* The user has been authenticated and accepted. */ |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 334 | packet_start(SSH_SMSG_SUCCESS); |
| 335 | packet_send(); |
| 336 | packet_write_wait(); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 337 | } |