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Damien Millereba71ba2000-04-29 23:57:08 +10001/*
2 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
3 * All rights reserved
Damien Millere4340be2000-09-16 13:29:08 +11004 *
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 Millereba71ba2000-04-29 23:57:08 +100010 */
11
12#include "includes.h"
Damien Millerd5580922003-05-14 13:40:06 +100013RCSID("$OpenBSD: auth1.c,v 1.48 2003/04/08 20:21:28 itojun Exp $");
Damien Millereba71ba2000-04-29 23:57:08 +100014
Damien Miller874d77b2000-10-14 16:23:11 +110015#include "xmalloc.h"
16#include "rsa.h"
Ben Lindstrom226cfa02001-01-22 05:34:40 +000017#include "ssh1.h"
Damien Miller874d77b2000-10-14 16:23:11 +110018#include "packet.h"
19#include "buffer.h"
20#include "mpaux.h"
Ben Lindstrom226cfa02001-01-22 05:34:40 +000021#include "log.h"
Damien Miller874d77b2000-10-14 16:23:11 +110022#include "servconf.h"
23#include "compat.h"
24#include "auth.h"
Damien Millerc7ef63d2002-02-05 12:21:42 +110025#include "channels.h"
Damien Miller874d77b2000-10-14 16:23:11 +110026#include "session.h"
Ben Lindstromec95ed92001-07-04 04:21:14 +000027#include "uidswap.h"
Ben Lindstrom7a2073c2002-03-22 02:30:41 +000028#include "monitor_wrap.h"
Damien Miller874d77b2000-10-14 16:23:11 +110029
Damien Millereba71ba2000-04-29 23:57:08 +100030/* import */
31extern ServerOptions options;
Damien Miller874d77b2000-10-14 16:23:11 +110032
Damien Millereba71ba2000-04-29 23:57:08 +100033/*
34 * convert ssh auth msg type into description
35 */
Ben Lindstrombba81212001-06-25 05:01:22 +000036static char *
Damien Millereba71ba2000-04-29 23:57:08 +100037get_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 Lindstromdb65e8f2001-01-19 04:26:52 +000049 case SSH_CMSG_AUTH_TIS:
50 case SSH_CMSG_AUTH_TIS_RESPONSE:
51 return "challenge-response";
Ben Lindstromec95ed92001-07-04 04:21:14 +000052#if defined(KRB4) || defined(KRB5)
Damien Millereba71ba2000-04-29 23:57:08 +100053 case SSH_CMSG_AUTH_KERBEROS:
54 return "kerberos";
55#endif
Damien Millereba71ba2000-04-29 23:57:08 +100056 }
57 snprintf(buf, sizeof buf, "bad-auth-msg-%d", type);
58 return buf;
59}
60
61/*
Ben Lindstromdb65e8f2001-01-19 04:26:52 +000062 * read packets, try to authenticate the user and
63 * return only if authentication is successful
Damien Millereba71ba2000-04-29 23:57:08 +100064 */
Ben Lindstrombba81212001-06-25 05:01:22 +000065static void
Ben Lindstromdb65e8f2001-01-19 04:26:52 +000066do_authloop(Authctxt *authctxt)
Damien Millereba71ba2000-04-29 23:57:08 +100067{
Damien Miller874d77b2000-10-14 16:23:11 +110068 int authenticated = 0;
Ben Lindstrom46c16222000-12-22 01:43:59 +000069 u_int bits;
Damien Millerda755162002-01-22 23:09:22 +110070 Key *client_host_key;
Damien Millereba71ba2000-04-29 23:57:08 +100071 BIGNUM *n;
Damien Miller874d77b2000-10-14 16:23:11 +110072 char *client_user, *password;
Ben Lindstromdb65e8f2001-01-19 04:26:52 +000073 char info[1024];
Ben Lindstrom46c16222000-12-22 01:43:59 +000074 u_int dlen;
Ben Lindstrom46c16222000-12-22 01:43:59 +000075 u_int ulen;
Damien Miller4f9f42a2003-05-10 19:28:02 +100076 int prev, type = 0;
Ben Lindstromdb65e8f2001-01-19 04:26:52 +000077 struct passwd *pw = authctxt->pw;
78
79 debug("Attempting authentication for %s%.100s.",
Damien Miller9f0f5c62001-12-21 14:45:46 +110080 authctxt->valid ? "" : "illegal user ", authctxt->user);
Ben Lindstromdb65e8f2001-01-19 04:26:52 +000081
82 /* If the user has no password, accept authentication immediately. */
83 if (options.password_authentication &&
Ben Lindstromec95ed92001-07-04 04:21:14 +000084#if defined(KRB4) || defined(KRB5)
Ben Lindstromdb65e8f2001-01-19 04:26:52 +000085 (!options.kerberos_authentication || options.kerberos_or_local_passwd) &&
86#endif
Ben Lindstrom7a2073c2002-03-22 02:30:41 +000087 PRIVSEP(auth_password(authctxt, ""))) {
Ben Lindstromdb65e8f2001-01-19 04:26:52 +000088 auth_log(authctxt, 1, "without authentication", "");
89 return;
90 }
Damien Millereba71ba2000-04-29 23:57:08 +100091
92 /* Indicate that authentication is needed. */
93 packet_start(SSH_SMSG_FAILURE);
94 packet_send();
95 packet_write_wait();
96
Damien Miller874d77b2000-10-14 16:23:11 +110097 client_user = NULL;
98
Ben Lindstromdb65e8f2001-01-19 04:26:52 +000099 for (;;) {
Damien Miller874d77b2000-10-14 16:23:11 +1100100 /* default to fail */
101 authenticated = 0;
102
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000103 info[0] = '\0';
Damien Millereba71ba2000-04-29 23:57:08 +1000104
105 /* Get a packet from the client. */
Damien Miller4f9f42a2003-05-10 19:28:02 +1000106 prev = type;
Damien Millerdff50992002-01-22 23:16:32 +1100107 type = packet_read();
Damien Millereba71ba2000-04-29 23:57:08 +1000108
Damien Miller4f9f42a2003-05-10 19:28:02 +1000109 /*
110 * If we started challenge-response authentication but the
111 * next packet is not a response to our challenge, release
112 * the resources allocated by get_challenge() (which would
113 * normally have been released by verify_response() had we
114 * received such a response)
115 */
116 if (prev == SSH_CMSG_AUTH_TIS &&
117 type != SSH_CMSG_AUTH_TIS_RESPONSE)
118 abandon_challenge_response(authctxt);
119
Damien Millereba71ba2000-04-29 23:57:08 +1000120 /* Process the packet. */
121 switch (type) {
Damien Millereba71ba2000-04-29 23:57:08 +1000122
Ben Lindstromec95ed92001-07-04 04:21:14 +0000123#if defined(KRB4) || defined(KRB5)
Damien Millereba71ba2000-04-29 23:57:08 +1000124 case SSH_CMSG_AUTH_KERBEROS:
125 if (!options.kerberos_authentication) {
Damien Millereba71ba2000-04-29 23:57:08 +1000126 verbose("Kerberos authentication disabled.");
Damien Millereba71ba2000-04-29 23:57:08 +1000127 } else {
Ben Lindstromec95ed92001-07-04 04:21:14 +0000128 char *kdata = packet_get_string(&dlen);
Damien Miller48b03fc2002-01-22 23:11:40 +1100129 packet_check_eom();
Damien Miller9f0f5c62001-12-21 14:45:46 +1100130
Ben Lindstromec95ed92001-07-04 04:21:14 +0000131 if (kdata[0] == 4) { /* KRB_PROT_VERSION */
132#ifdef KRB4
Damien Millerd94e5492002-09-27 13:25:58 +1000133 KTEXT_ST tkt, reply;
Ben Lindstromec95ed92001-07-04 04:21:14 +0000134 tkt.length = dlen;
135 if (tkt.length < MAX_KTXT_LEN)
136 memcpy(tkt.dat, kdata, tkt.length);
Damien Miller9f0f5c62001-12-21 14:45:46 +1100137
Damien Millerd94e5492002-09-27 13:25:58 +1000138 if (PRIVSEP(auth_krb4(authctxt, &tkt,
139 &client_user, &reply))) {
Ben Lindstromec95ed92001-07-04 04:21:14 +0000140 authenticated = 1;
141 snprintf(info, sizeof(info),
142 " tktuser %.100s",
143 client_user);
Damien Millerd94e5492002-09-27 13:25:58 +1000144
145 packet_start(
146 SSH_SMSG_AUTH_KERBEROS_RESPONSE);
147 packet_put_string((char *)
148 reply.dat, reply.length);
149 packet_send();
150 packet_write_wait();
Damien Miller874d77b2000-10-14 16:23:11 +1100151 }
Ben Lindstromec95ed92001-07-04 04:21:14 +0000152#endif /* KRB4 */
153 } else {
154#ifdef KRB5
Damien Miller25162f22002-09-12 09:47:29 +1000155 krb5_data tkt, reply;
Ben Lindstromec95ed92001-07-04 04:21:14 +0000156 tkt.length = dlen;
157 tkt.data = kdata;
Damien Miller9f0f5c62001-12-21 14:45:46 +1100158
Damien Miller25162f22002-09-12 09:47:29 +1000159 if (PRIVSEP(auth_krb5(authctxt, &tkt,
160 &client_user, &reply))) {
Ben Lindstromec95ed92001-07-04 04:21:14 +0000161 authenticated = 1;
162 snprintf(info, sizeof(info),
163 " tktuser %.100s",
164 client_user);
Ben Lindstrom93576d92002-12-23 02:06:19 +0000165
Damien Miller25162f22002-09-12 09:47:29 +1000166 /* Send response to client */
167 packet_start(
168 SSH_SMSG_AUTH_KERBEROS_RESPONSE);
169 packet_put_string((char *)
170 reply.data, reply.length);
171 packet_send();
172 packet_write_wait();
173
174 if (reply.length)
175 xfree(reply.data);
Ben Lindstromec95ed92001-07-04 04:21:14 +0000176 }
177#endif /* KRB5 */
Damien Millereba71ba2000-04-29 23:57:08 +1000178 }
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000179 xfree(kdata);
Damien Millereba71ba2000-04-29 23:57:08 +1000180 }
181 break;
Ben Lindstromec95ed92001-07-04 04:21:14 +0000182#endif /* KRB4 || KRB5 */
Damien Miller9f0f5c62001-12-21 14:45:46 +1100183
Ben Lindstromec95ed92001-07-04 04:21:14 +0000184#if defined(AFS) || defined(KRB5)
185 /* XXX - punt on backward compatibility here. */
186 case SSH_CMSG_HAVE_KERBEROS_TGT:
187 packet_send_debug("Kerberos TGT passing disabled before authentication.");
188 break;
189#ifdef AFS
190 case SSH_CMSG_HAVE_AFS_TOKEN:
191 packet_send_debug("AFS token passing disabled before authentication.");
192 break;
193#endif /* AFS */
194#endif /* AFS || KRB5 */
Damien Miller9f0f5c62001-12-21 14:45:46 +1100195
Damien Millereba71ba2000-04-29 23:57:08 +1000196 case SSH_CMSG_AUTH_RHOSTS:
197 if (!options.rhosts_authentication) {
198 verbose("Rhosts authentication disabled.");
199 break;
200 }
201 /*
202 * Get client user name. Note that we just have to
203 * trust the client; this is one reason why rhosts
204 * authentication is insecure. (Another is
205 * IP-spoofing on a local network.)
206 */
207 client_user = packet_get_string(&ulen);
Damien Miller48b03fc2002-01-22 23:11:40 +1100208 packet_check_eom();
Damien Millereba71ba2000-04-29 23:57:08 +1000209
Damien Miller874d77b2000-10-14 16:23:11 +1100210 /* Try to authenticate using /etc/hosts.equiv and .rhosts. */
Damien Millereba71ba2000-04-29 23:57:08 +1000211 authenticated = auth_rhosts(pw, client_user);
212
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000213 snprintf(info, sizeof info, " ruser %.100s", client_user);
Damien Millereba71ba2000-04-29 23:57:08 +1000214 break;
215
216 case SSH_CMSG_AUTH_RHOSTS_RSA:
217 if (!options.rhosts_rsa_authentication) {
218 verbose("Rhosts with RSA authentication disabled.");
219 break;
220 }
221 /*
222 * Get client user name. Note that we just have to
223 * trust the client; root on the client machine can
224 * claim to be any user.
225 */
226 client_user = packet_get_string(&ulen);
227
228 /* Get the client host key. */
Damien Millerda755162002-01-22 23:09:22 +1100229 client_host_key = key_new(KEY_RSA1);
Damien Millereba71ba2000-04-29 23:57:08 +1000230 bits = packet_get_int();
Damien Millerd432ccf2002-01-22 23:14:44 +1100231 packet_get_bignum(client_host_key->rsa->e);
232 packet_get_bignum(client_host_key->rsa->n);
Damien Millereba71ba2000-04-29 23:57:08 +1000233
Damien Millerda755162002-01-22 23:09:22 +1100234 if (bits != BN_num_bits(client_host_key->rsa->n))
Damien Miller874d77b2000-10-14 16:23:11 +1100235 verbose("Warning: keysize mismatch for client_host_key: "
Damien Millerda755162002-01-22 23:09:22 +1100236 "actual %d, announced %d",
Ben Lindstromcb72e4f2002-06-21 00:41:51 +0000237 BN_num_bits(client_host_key->rsa->n), bits);
Damien Miller48b03fc2002-01-22 23:11:40 +1100238 packet_check_eom();
Damien Millereba71ba2000-04-29 23:57:08 +1000239
Damien Millerda755162002-01-22 23:09:22 +1100240 authenticated = auth_rhosts_rsa(pw, client_user,
Damien Millerd221ca62002-01-22 23:11:00 +1100241 client_host_key);
Damien Millerda755162002-01-22 23:09:22 +1100242 key_free(client_host_key);
Damien Millereba71ba2000-04-29 23:57:08 +1000243
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000244 snprintf(info, sizeof info, " ruser %.100s", client_user);
Damien Millereba71ba2000-04-29 23:57:08 +1000245 break;
246
247 case SSH_CMSG_AUTH_RSA:
248 if (!options.rsa_authentication) {
249 verbose("RSA authentication disabled.");
250 break;
251 }
252 /* RSA authentication requested. */
Damien Millerda755162002-01-22 23:09:22 +1100253 if ((n = BN_new()) == NULL)
254 fatal("do_authloop: BN_new failed");
Damien Millerd432ccf2002-01-22 23:14:44 +1100255 packet_get_bignum(n);
Damien Miller48b03fc2002-01-22 23:11:40 +1100256 packet_check_eom();
Damien Millereba71ba2000-04-29 23:57:08 +1000257 authenticated = auth_rsa(pw, n);
258 BN_clear_free(n);
259 break;
260
261 case SSH_CMSG_AUTH_PASSWORD:
262 if (!options.password_authentication) {
263 verbose("Password authentication disabled.");
264 break;
265 }
266 /*
267 * Read user password. It is in plain text, but was
268 * transmitted over the encrypted channel so it is
269 * not visible to an outside observer.
270 */
271 password = packet_get_string(&dlen);
Damien Miller48b03fc2002-01-22 23:11:40 +1100272 packet_check_eom();
Damien Millereba71ba2000-04-29 23:57:08 +1000273
Kevin Steves12aaa042001-01-24 21:23:39 +0000274 /* Try authentication with the password. */
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000275 authenticated = PRIVSEP(auth_password(authctxt, password));
Damien Millereba71ba2000-04-29 23:57:08 +1000276
277 memset(password, 0, strlen(password));
278 xfree(password);
279 break;
280
Damien Millereba71ba2000-04-29 23:57:08 +1000281 case SSH_CMSG_AUTH_TIS:
282 debug("rcvd SSH_CMSG_AUTH_TIS");
Ben Lindstrom551ea372001-06-05 18:56:16 +0000283 if (options.challenge_response_authentication == 1) {
284 char *challenge = get_challenge(authctxt);
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000285 if (challenge != NULL) {
286 debug("sending challenge '%s'", challenge);
Damien Millereba71ba2000-04-29 23:57:08 +1000287 packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE);
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000288 packet_put_cstring(challenge);
Ben Lindstrom551ea372001-06-05 18:56:16 +0000289 xfree(challenge);
Damien Millereba71ba2000-04-29 23:57:08 +1000290 packet_send();
291 packet_write_wait();
292 continue;
293 }
294 }
295 break;
296 case SSH_CMSG_AUTH_TIS_RESPONSE:
297 debug("rcvd SSH_CMSG_AUTH_TIS_RESPONSE");
Ben Lindstrom551ea372001-06-05 18:56:16 +0000298 if (options.challenge_response_authentication == 1) {
Damien Millereba71ba2000-04-29 23:57:08 +1000299 char *response = packet_get_string(&dlen);
Damien Miller48b03fc2002-01-22 23:11:40 +1100300 packet_check_eom();
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000301 authenticated = verify_response(authctxt, response);
302 memset(response, 'r', dlen);
Damien Millereba71ba2000-04-29 23:57:08 +1000303 xfree(response);
304 }
305 break;
Damien Millereba71ba2000-04-29 23:57:08 +1000306
307 default:
308 /*
309 * Any unknown messages will be ignored (and failure
310 * returned) during authentication.
311 */
Damien Miller996acd22003-04-09 20:59:48 +1000312 logit("Unknown message during authentication: type %d", type);
Damien Millereba71ba2000-04-29 23:57:08 +1000313 break;
314 }
Damien Miller60396b02001-02-18 17:01:00 +1100315#ifdef BSD_AUTH
316 if (authctxt->as) {
317 auth_close(authctxt->as);
318 authctxt->as = NULL;
319 }
320#endif
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000321 if (!authctxt->valid && authenticated)
322 fatal("INTERNAL ERROR: authenticated invalid user %s",
323 authctxt->user);
Damien Millereba71ba2000-04-29 23:57:08 +1000324
Tim Rice81ed5182002-09-25 17:38:46 -0700325#ifdef _UNICOS
Tim Rice81ed5182002-09-25 17:38:46 -0700326 if (authenticated && cray_access_denied(authctxt->user)) {
327 authenticated = 0;
328 fatal("Access denied for user %s.",authctxt->user);
329 }
330#endif /* _UNICOS */
331
Kevin Stevesef4eea92001-02-05 12:42:17 +0000332#ifdef HAVE_CYGWIN
333 if (authenticated &&
Damien Miller0dea79d2001-12-29 14:08:28 +1100334 !check_nt_auth(type == SSH_CMSG_AUTH_PASSWORD, pw)) {
Damien Millerbac2d8a2000-09-05 16:13:06 +1100335 packet_disconnect("Authentication rejected for uid %d.",
Damien Miller0dea79d2001-12-29 14:08:28 +1100336 pw == NULL ? -1 : pw->pw_uid);
Damien Millerbac2d8a2000-09-05 16:13:06 +1100337 authenticated = 0;
338 }
Ben Lindstrom5dc81502001-01-19 06:10:29 +0000339#else
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000340 /* Special handling for root */
Damien Miller556f9312003-02-24 11:59:26 +1100341 if (authenticated && authctxt->pw->pw_uid == 0 &&
Ben Lindstromd8a90212001-02-15 03:08:27 +0000342 !auth_root_allowed(get_authname(type)))
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000343 authenticated = 0;
Ben Lindstrom5dc81502001-01-19 06:10:29 +0000344#endif
Damien Millereba71ba2000-04-29 23:57:08 +1000345
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000346 /* Log before sending the reply */
347 auth_log(authctxt, authenticated, get_authname(type), info);
348
Damien Millereba71ba2000-04-29 23:57:08 +1000349 if (client_user != NULL) {
350 xfree(client_user);
351 client_user = NULL;
352 }
353
Damien Miller874d77b2000-10-14 16:23:11 +1100354 if (authenticated)
355 return;
356
Ben Lindstrom683036e2003-04-27 18:41:30 +0000357 if (authctxt->failures++ > AUTH_FAIL_MAX)
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000358 packet_disconnect(AUTH_FAIL_MSG, authctxt->user);
Damien Millereba71ba2000-04-29 23:57:08 +1000359
Damien Millereba71ba2000-04-29 23:57:08 +1000360 packet_start(SSH_SMSG_FAILURE);
361 packet_send();
362 packet_write_wait();
363 }
364}
365
366/*
367 * Performs authentication of an incoming connection. Session key has already
368 * been exchanged and encryption is enabled.
369 */
Ben Lindstrom73ab9ba2002-03-22 01:27:35 +0000370Authctxt *
Ben Lindstrom3c36bb22001-12-06 17:55:26 +0000371do_authentication(void)
Damien Millereba71ba2000-04-29 23:57:08 +1000372{
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000373 Authctxt *authctxt;
Ben Lindstrom46c16222000-12-22 01:43:59 +0000374 u_int ulen;
Ben Lindstromc8226382002-04-10 16:22:09 +0000375 char *user, *style = NULL;
Damien Millereba71ba2000-04-29 23:57:08 +1000376
377 /* Get the name of the user that we wish to log in as. */
Damien Millerdff50992002-01-22 23:16:32 +1100378 packet_read_expect(SSH_CMSG_USER);
Damien Millereba71ba2000-04-29 23:57:08 +1000379
380 /* Get the user name. */
381 user = packet_get_string(&ulen);
Damien Miller48b03fc2002-01-22 23:11:40 +1100382 packet_check_eom();
Damien Millereba71ba2000-04-29 23:57:08 +1000383
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000384 if ((style = strchr(user, ':')) != NULL)
Ben Lindstromec95ed92001-07-04 04:21:14 +0000385 *style++ = '\0';
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000386
Ben Lindstromc8226382002-04-10 16:22:09 +0000387#ifdef KRB5
Ben Lindstromec95ed92001-07-04 04:21:14 +0000388 /* XXX - SSH.com Kerberos v5 braindeath. */
Ben Lindstromc8226382002-04-10 16:22:09 +0000389 if ((datafellows & SSH_BUG_K5USER) &&
390 options.kerberos_authentication) {
391 char *p;
392 if ((p = strchr(user, '@')) != NULL)
393 *p = '\0';
394 }
395#endif
Damien Miller9f0f5c62001-12-21 14:45:46 +1100396
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000397 authctxt = authctxt_new();
398 authctxt->user = user;
399 authctxt->style = style;
400
Damien Millereba71ba2000-04-29 23:57:08 +1000401 /* Verify that the user is a valid user. */
Ben Lindstrom7ebb6352002-03-22 03:04:08 +0000402 if ((authctxt->pw = PRIVSEP(getpwnamallow(user))) != NULL)
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000403 authctxt->valid = 1;
Ben Lindstrom7ebb6352002-03-22 03:04:08 +0000404 else
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000405 debug("do_authentication: illegal user %s", user);
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000406
Ben Lindstrom7ebb6352002-03-22 03:04:08 +0000407 setproctitle("%s%s", authctxt->pw ? user : "unknown",
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000408 use_privsep ? " [net]" : "");
Ben Lindstromc1ba31f2001-02-15 03:14:11 +0000409
Damien Millereba71ba2000-04-29 23:57:08 +1000410#ifdef USE_PAM
Damien Miller4e448a32003-05-14 15:11:48 +1000411 if (options.use_pam)
412 PRIVSEP(start_pam(user));
Damien Millereba71ba2000-04-29 23:57:08 +1000413#endif
414
415 /*
416 * If we are not running as root, the user must have the same uid as
Damien Miller874d77b2000-10-14 16:23:11 +1100417 * the server. (Unless you are running Windows)
Damien Millereba71ba2000-04-29 23:57:08 +1000418 */
Damien Miller874d77b2000-10-14 16:23:11 +1100419#ifndef HAVE_CYGWIN
Ben Lindstrom7ebb6352002-03-22 03:04:08 +0000420 if (!use_privsep && getuid() != 0 && authctxt->pw &&
421 authctxt->pw->pw_uid != getuid())
Damien Millereba71ba2000-04-29 23:57:08 +1000422 packet_disconnect("Cannot change user when server not running as root.");
Damien Millerbac2d8a2000-09-05 16:13:06 +1100423#endif
Damien Millereba71ba2000-04-29 23:57:08 +1000424
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000425 /*
Kevin Steves12aaa042001-01-24 21:23:39 +0000426 * Loop until the user has been authenticated or the connection is
427 * closed, do_authloop() returns only if authentication is successful
428 */
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000429 do_authloop(authctxt);
Damien Millereba71ba2000-04-29 23:57:08 +1000430
431 /* The user has been authenticated and accepted. */
Damien Miller874d77b2000-10-14 16:23:11 +1100432 packet_start(SSH_SMSG_SUCCESS);
433 packet_send();
434 packet_write_wait();
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000435
Ben Lindstrom73ab9ba2002-03-22 01:27:35 +0000436 return (authctxt);
Damien Millereba71ba2000-04-29 23:57:08 +1000437}