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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 Millerc7ef63d2002-02-05 12:21:42 +110013RCSID("$OpenBSD: auth1.c,v 1.35 2002/02/03 17:53:25 markus 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 Lindstrom086cf212001-03-05 05:56:40 +000027#include "misc.h"
Ben Lindstromec95ed92001-07-04 04:21:14 +000028#include "uidswap.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 Millereba71ba2000-04-29 23:57:08 +100076 int 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 Lindstromb100ec92001-01-19 05:37:32 +000087#ifdef USE_PAM
Kevin Stevesbca8c8f2001-02-13 11:26:21 +000088 auth_pam_password(pw, "")) {
Damien Miller92ddb7d2001-02-14 01:25:23 +110089#elif defined(HAVE_OSF_SIA)
90 0) {
Ben Lindstromdb65e8f2001-01-19 04:26:52 +000091#else
Damien Miller60396b02001-02-18 17:01:00 +110092 auth_password(authctxt, "")) {
Ben Lindstromdb65e8f2001-01-19 04:26:52 +000093#endif
94 auth_log(authctxt, 1, "without authentication", "");
95 return;
96 }
Damien Millereba71ba2000-04-29 23:57:08 +100097
98 /* Indicate that authentication is needed. */
99 packet_start(SSH_SMSG_FAILURE);
100 packet_send();
101 packet_write_wait();
102
Damien Miller874d77b2000-10-14 16:23:11 +1100103 client_user = NULL;
104
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000105 for (;;) {
Damien Miller874d77b2000-10-14 16:23:11 +1100106 /* default to fail */
107 authenticated = 0;
108
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000109 info[0] = '\0';
Damien Millereba71ba2000-04-29 23:57:08 +1000110
111 /* Get a packet from the client. */
Damien Millerdff50992002-01-22 23:16:32 +1100112 type = packet_read();
Damien Millereba71ba2000-04-29 23:57:08 +1000113
114 /* Process the packet. */
115 switch (type) {
Damien Millereba71ba2000-04-29 23:57:08 +1000116
Ben Lindstromec95ed92001-07-04 04:21:14 +0000117#if defined(KRB4) || defined(KRB5)
Damien Millereba71ba2000-04-29 23:57:08 +1000118 case SSH_CMSG_AUTH_KERBEROS:
119 if (!options.kerberos_authentication) {
Damien Millereba71ba2000-04-29 23:57:08 +1000120 verbose("Kerberos authentication disabled.");
Damien Millereba71ba2000-04-29 23:57:08 +1000121 } else {
Ben Lindstromec95ed92001-07-04 04:21:14 +0000122 char *kdata = packet_get_string(&dlen);
Damien Miller48b03fc2002-01-22 23:11:40 +1100123 packet_check_eom();
Damien Miller9f0f5c62001-12-21 14:45:46 +1100124
Ben Lindstromec95ed92001-07-04 04:21:14 +0000125 if (kdata[0] == 4) { /* KRB_PROT_VERSION */
126#ifdef KRB4
127 KTEXT_ST tkt;
Damien Miller9f0f5c62001-12-21 14:45:46 +1100128
Ben Lindstromec95ed92001-07-04 04:21:14 +0000129 tkt.length = dlen;
130 if (tkt.length < MAX_KTXT_LEN)
131 memcpy(tkt.dat, kdata, tkt.length);
Damien Miller9f0f5c62001-12-21 14:45:46 +1100132
Ben Lindstromec95ed92001-07-04 04:21:14 +0000133 if (auth_krb4(authctxt, &tkt, &client_user)) {
134 authenticated = 1;
135 snprintf(info, sizeof(info),
136 " tktuser %.100s",
137 client_user);
Damien Miller874d77b2000-10-14 16:23:11 +1100138 }
Ben Lindstromec95ed92001-07-04 04:21:14 +0000139#endif /* KRB4 */
140 } else {
141#ifdef KRB5
142 krb5_data tkt;
143 tkt.length = dlen;
144 tkt.data = kdata;
Damien Miller9f0f5c62001-12-21 14:45:46 +1100145
Ben Lindstromec95ed92001-07-04 04:21:14 +0000146 if (auth_krb5(authctxt, &tkt, &client_user)) {
147 authenticated = 1;
148 snprintf(info, sizeof(info),
149 " tktuser %.100s",
150 client_user);
Ben Lindstromec95ed92001-07-04 04:21:14 +0000151 }
152#endif /* KRB5 */
Damien Millereba71ba2000-04-29 23:57:08 +1000153 }
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000154 xfree(kdata);
Damien Millereba71ba2000-04-29 23:57:08 +1000155 }
156 break;
Ben Lindstromec95ed92001-07-04 04:21:14 +0000157#endif /* KRB4 || KRB5 */
Damien Miller9f0f5c62001-12-21 14:45:46 +1100158
Ben Lindstromec95ed92001-07-04 04:21:14 +0000159#if defined(AFS) || defined(KRB5)
160 /* XXX - punt on backward compatibility here. */
161 case SSH_CMSG_HAVE_KERBEROS_TGT:
162 packet_send_debug("Kerberos TGT passing disabled before authentication.");
163 break;
164#ifdef AFS
165 case SSH_CMSG_HAVE_AFS_TOKEN:
166 packet_send_debug("AFS token passing disabled before authentication.");
167 break;
168#endif /* AFS */
169#endif /* AFS || KRB5 */
Damien Miller9f0f5c62001-12-21 14:45:46 +1100170
Damien Millereba71ba2000-04-29 23:57:08 +1000171 case SSH_CMSG_AUTH_RHOSTS:
172 if (!options.rhosts_authentication) {
173 verbose("Rhosts authentication disabled.");
174 break;
175 }
176 /*
177 * Get client user name. Note that we just have to
178 * trust the client; this is one reason why rhosts
179 * authentication is insecure. (Another is
180 * IP-spoofing on a local network.)
181 */
182 client_user = packet_get_string(&ulen);
Damien Miller48b03fc2002-01-22 23:11:40 +1100183 packet_check_eom();
Damien Millereba71ba2000-04-29 23:57:08 +1000184
Damien Miller874d77b2000-10-14 16:23:11 +1100185 /* Try to authenticate using /etc/hosts.equiv and .rhosts. */
Damien Millereba71ba2000-04-29 23:57:08 +1000186 authenticated = auth_rhosts(pw, client_user);
187
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000188 snprintf(info, sizeof info, " ruser %.100s", client_user);
Damien Millereba71ba2000-04-29 23:57:08 +1000189 break;
190
191 case SSH_CMSG_AUTH_RHOSTS_RSA:
192 if (!options.rhosts_rsa_authentication) {
193 verbose("Rhosts with RSA authentication disabled.");
194 break;
195 }
196 /*
197 * Get client user name. Note that we just have to
198 * trust the client; root on the client machine can
199 * claim to be any user.
200 */
201 client_user = packet_get_string(&ulen);
202
203 /* Get the client host key. */
Damien Millerda755162002-01-22 23:09:22 +1100204 client_host_key = key_new(KEY_RSA1);
Damien Millereba71ba2000-04-29 23:57:08 +1000205 bits = packet_get_int();
Damien Millerd432ccf2002-01-22 23:14:44 +1100206 packet_get_bignum(client_host_key->rsa->e);
207 packet_get_bignum(client_host_key->rsa->n);
Damien Millereba71ba2000-04-29 23:57:08 +1000208
Damien Millerda755162002-01-22 23:09:22 +1100209 if (bits != BN_num_bits(client_host_key->rsa->n))
Damien Miller874d77b2000-10-14 16:23:11 +1100210 verbose("Warning: keysize mismatch for client_host_key: "
Damien Millerda755162002-01-22 23:09:22 +1100211 "actual %d, announced %d",
212 BN_num_bits(client_host_key->rsa->n), bits);
Damien Miller48b03fc2002-01-22 23:11:40 +1100213 packet_check_eom();
Damien Millereba71ba2000-04-29 23:57:08 +1000214
Damien Millerda755162002-01-22 23:09:22 +1100215 authenticated = auth_rhosts_rsa(pw, client_user,
Damien Millerd221ca62002-01-22 23:11:00 +1100216 client_host_key);
Damien Millerda755162002-01-22 23:09:22 +1100217 key_free(client_host_key);
Damien Millereba71ba2000-04-29 23:57:08 +1000218
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000219 snprintf(info, sizeof info, " ruser %.100s", client_user);
Damien Millereba71ba2000-04-29 23:57:08 +1000220 break;
221
222 case SSH_CMSG_AUTH_RSA:
223 if (!options.rsa_authentication) {
224 verbose("RSA authentication disabled.");
225 break;
226 }
227 /* RSA authentication requested. */
Damien Millerda755162002-01-22 23:09:22 +1100228 if ((n = BN_new()) == NULL)
229 fatal("do_authloop: BN_new failed");
Damien Millerd432ccf2002-01-22 23:14:44 +1100230 packet_get_bignum(n);
Damien Miller48b03fc2002-01-22 23:11:40 +1100231 packet_check_eom();
Damien Millereba71ba2000-04-29 23:57:08 +1000232 authenticated = auth_rsa(pw, n);
233 BN_clear_free(n);
234 break;
235
236 case SSH_CMSG_AUTH_PASSWORD:
237 if (!options.password_authentication) {
238 verbose("Password authentication disabled.");
239 break;
240 }
241 /*
242 * Read user password. It is in plain text, but was
243 * transmitted over the encrypted channel so it is
244 * not visible to an outside observer.
245 */
246 password = packet_get_string(&dlen);
Damien Miller48b03fc2002-01-22 23:11:40 +1100247 packet_check_eom();
Damien Millereba71ba2000-04-29 23:57:08 +1000248
249#ifdef USE_PAM
250 /* Do PAM auth with password */
251 authenticated = auth_pam_password(pw, password);
Damien Millerb8c656e2000-06-28 15:22:41 +1000252#elif defined(HAVE_OSF_SIA)
253 /* Do SIA auth with password */
Damien Miller92ddb7d2001-02-14 01:25:23 +1100254 authenticated = auth_sia_password(authctxt->user,
255 password);
Damien Millerb8c656e2000-06-28 15:22:41 +1000256#else /* !USE_PAM && !HAVE_OSF_SIA */
Kevin Steves12aaa042001-01-24 21:23:39 +0000257 /* Try authentication with the password. */
Damien Miller60396b02001-02-18 17:01:00 +1100258 authenticated = auth_password(authctxt, password);
Damien Millereba71ba2000-04-29 23:57:08 +1000259#endif /* USE_PAM */
260
261 memset(password, 0, strlen(password));
262 xfree(password);
263 break;
264
Damien Millereba71ba2000-04-29 23:57:08 +1000265 case SSH_CMSG_AUTH_TIS:
266 debug("rcvd SSH_CMSG_AUTH_TIS");
Ben Lindstrom551ea372001-06-05 18:56:16 +0000267 if (options.challenge_response_authentication == 1) {
268 char *challenge = get_challenge(authctxt);
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000269 if (challenge != NULL) {
270 debug("sending challenge '%s'", challenge);
Damien Millereba71ba2000-04-29 23:57:08 +1000271 packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE);
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000272 packet_put_cstring(challenge);
Ben Lindstrom551ea372001-06-05 18:56:16 +0000273 xfree(challenge);
Damien Millereba71ba2000-04-29 23:57:08 +1000274 packet_send();
275 packet_write_wait();
276 continue;
277 }
278 }
279 break;
280 case SSH_CMSG_AUTH_TIS_RESPONSE:
281 debug("rcvd SSH_CMSG_AUTH_TIS_RESPONSE");
Ben Lindstrom551ea372001-06-05 18:56:16 +0000282 if (options.challenge_response_authentication == 1) {
Damien Millereba71ba2000-04-29 23:57:08 +1000283 char *response = packet_get_string(&dlen);
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000284 debug("got response '%s'", response);
Damien Miller48b03fc2002-01-22 23:11:40 +1100285 packet_check_eom();
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000286 authenticated = verify_response(authctxt, response);
287 memset(response, 'r', dlen);
Damien Millereba71ba2000-04-29 23:57:08 +1000288 xfree(response);
289 }
290 break;
Damien Millereba71ba2000-04-29 23:57:08 +1000291
292 default:
293 /*
294 * Any unknown messages will be ignored (and failure
295 * returned) during authentication.
296 */
297 log("Unknown message during authentication: type %d", type);
298 break;
299 }
Damien Miller60396b02001-02-18 17:01:00 +1100300#ifdef BSD_AUTH
301 if (authctxt->as) {
302 auth_close(authctxt->as);
303 authctxt->as = NULL;
304 }
305#endif
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000306 if (!authctxt->valid && authenticated)
307 fatal("INTERNAL ERROR: authenticated invalid user %s",
308 authctxt->user);
Damien Millereba71ba2000-04-29 23:57:08 +1000309
Kevin Stevesef4eea92001-02-05 12:42:17 +0000310#ifdef HAVE_CYGWIN
311 if (authenticated &&
Damien Miller0dea79d2001-12-29 14:08:28 +1100312 !check_nt_auth(type == SSH_CMSG_AUTH_PASSWORD, pw)) {
Damien Millerbac2d8a2000-09-05 16:13:06 +1100313 packet_disconnect("Authentication rejected for uid %d.",
Damien Miller0dea79d2001-12-29 14:08:28 +1100314 pw == NULL ? -1 : pw->pw_uid);
Damien Millerbac2d8a2000-09-05 16:13:06 +1100315 authenticated = 0;
316 }
Ben Lindstrom5dc81502001-01-19 06:10:29 +0000317#else
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000318 /* Special handling for root */
Ben Lindstromd8a90212001-02-15 03:08:27 +0000319 if (authenticated && authctxt->pw->pw_uid == 0 &&
320 !auth_root_allowed(get_authname(type)))
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000321 authenticated = 0;
Ben Lindstrom5dc81502001-01-19 06:10:29 +0000322#endif
Kevin Stevesef4eea92001-02-05 12:42:17 +0000323#ifdef USE_PAM
Damien Miller874d77b2000-10-14 16:23:11 +1100324 if (authenticated && !do_pam_account(pw->pw_name, client_user))
325 authenticated = 0;
326#endif
Damien Millereba71ba2000-04-29 23:57:08 +1000327
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000328 /* Log before sending the reply */
329 auth_log(authctxt, authenticated, get_authname(type), info);
330
Damien Millereba71ba2000-04-29 23:57:08 +1000331 if (client_user != NULL) {
332 xfree(client_user);
333 client_user = NULL;
334 }
335
Damien Miller874d77b2000-10-14 16:23:11 +1100336 if (authenticated)
337 return;
338
Kevin Steves12aaa042001-01-24 21:23:39 +0000339 if (authctxt->failures++ > AUTH_FAIL_MAX) {
Kevin Stevesef4eea92001-02-05 12:42:17 +0000340#ifdef WITH_AIXAUTHENTICATE
341 loginfailed(authctxt->user,
Damien Millerf3451a22002-02-05 12:40:46 +1100342 get_canonical_hostname(options.verify_reverse_mapping),
Damien Miller33804262001-02-04 23:20:18 +1100343 "ssh");
Damien Millerd2c208a2000-05-17 22:00:02 +1000344#endif /* WITH_AIXAUTHENTICATE */
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000345 packet_disconnect(AUTH_FAIL_MSG, authctxt->user);
Damien Millerd2c208a2000-05-17 22:00:02 +1000346 }
Damien Millereba71ba2000-04-29 23:57:08 +1000347
Damien Millereba71ba2000-04-29 23:57:08 +1000348 packet_start(SSH_SMSG_FAILURE);
349 packet_send();
350 packet_write_wait();
351 }
352}
353
354/*
355 * Performs authentication of an incoming connection. Session key has already
356 * been exchanged and encryption is enabled.
357 */
Damien Miller3a5b0232002-03-13 13:19:42 +1100358void
Ben Lindstrom3c36bb22001-12-06 17:55:26 +0000359do_authentication(void)
Damien Millereba71ba2000-04-29 23:57:08 +1000360{
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000361 Authctxt *authctxt;
Damien Miller3a5b0232002-03-13 13:19:42 +1100362 struct passwd *pw;
Ben Lindstrom46c16222000-12-22 01:43:59 +0000363 u_int ulen;
Ben Lindstromec95ed92001-07-04 04:21:14 +0000364 char *p, *user, *style = NULL;
Damien Millereba71ba2000-04-29 23:57:08 +1000365
366 /* Get the name of the user that we wish to log in as. */
Damien Millerdff50992002-01-22 23:16:32 +1100367 packet_read_expect(SSH_CMSG_USER);
Damien Millereba71ba2000-04-29 23:57:08 +1000368
369 /* Get the user name. */
370 user = packet_get_string(&ulen);
Damien Miller48b03fc2002-01-22 23:11:40 +1100371 packet_check_eom();
Damien Millereba71ba2000-04-29 23:57:08 +1000372
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000373 if ((style = strchr(user, ':')) != NULL)
Ben Lindstromec95ed92001-07-04 04:21:14 +0000374 *style++ = '\0';
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000375
Ben Lindstromec95ed92001-07-04 04:21:14 +0000376 /* XXX - SSH.com Kerberos v5 braindeath. */
377 if ((p = strchr(user, '@')) != NULL)
378 *p = '\0';
Damien Miller9f0f5c62001-12-21 14:45:46 +1100379
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000380 authctxt = authctxt_new();
381 authctxt->user = user;
382 authctxt->style = style;
383
Damien Millereba71ba2000-04-29 23:57:08 +1000384 /* Verify that the user is a valid user. */
Damien Miller3a5b0232002-03-13 13:19:42 +1100385 pw = getpwnam(user);
386 if (pw && allowed_user(pw)) {
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000387 authctxt->valid = 1;
Damien Miller3a5b0232002-03-13 13:19:42 +1100388 pw = pwcopy(pw);
Damien Miller874d77b2000-10-14 16:23:11 +1100389 } else {
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000390 debug("do_authentication: illegal user %s", user);
Damien Miller874d77b2000-10-14 16:23:11 +1100391 pw = NULL;
392 }
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000393 authctxt->pw = pw;
Damien Millereba71ba2000-04-29 23:57:08 +1000394
Damien Miller3a5b0232002-03-13 13:19:42 +1100395 setproctitle("%s", pw ? user : "unknown");
Ben Lindstromc1ba31f2001-02-15 03:14:11 +0000396
Damien Millereba71ba2000-04-29 23:57:08 +1000397#ifdef USE_PAM
Damien Miller72476d42002-02-14 20:39:49 +1100398 start_pam(pw == NULL ? "NOUSER" : user);
Damien Millereba71ba2000-04-29 23:57:08 +1000399#endif
400
401 /*
402 * If we are not running as root, the user must have the same uid as
Damien Miller874d77b2000-10-14 16:23:11 +1100403 * the server. (Unless you are running Windows)
Damien Millereba71ba2000-04-29 23:57:08 +1000404 */
Damien Miller874d77b2000-10-14 16:23:11 +1100405#ifndef HAVE_CYGWIN
406 if (getuid() != 0 && pw && pw->pw_uid != getuid())
Damien Millereba71ba2000-04-29 23:57:08 +1000407 packet_disconnect("Cannot change user when server not running as root.");
Damien Millerbac2d8a2000-09-05 16:13:06 +1100408#endif
Damien Millereba71ba2000-04-29 23:57:08 +1000409
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000410 /*
Kevin Steves12aaa042001-01-24 21:23:39 +0000411 * Loop until the user has been authenticated or the connection is
412 * closed, do_authloop() returns only if authentication is successful
413 */
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000414 do_authloop(authctxt);
Damien Millereba71ba2000-04-29 23:57:08 +1000415
416 /* The user has been authenticated and accepted. */
Damien Miller874d77b2000-10-14 16:23:11 +1100417 packet_start(SSH_SMSG_SUCCESS);
418 packet_send();
419 packet_write_wait();
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000420
Damien Miller3a5b0232002-03-13 13:19:42 +1100421 /* Perform session preparation. */
422 do_authenticated(authctxt);
Damien Millereba71ba2000-04-29 23:57:08 +1000423}