2 * Copyright (c) 2000 Markus Friedl. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 RCSID("$OpenBSD: auth2.c,v 1.95 2002/08/22 21:33:58 markus Exp $");
27 RCSID("$FreeBSD: src/crypto/openssh/auth2.c,v 1.2.2.9 2003/02/03 17:31:06 des Exp $");
28 RCSID("$DragonFly: src/crypto/openssh/Attic/auth2.c,v 1.2 2003/06/17 04:24:36 dillon Exp $");
39 #include "pathnames.h"
40 #include "monitor_wrap.h"
43 extern ServerOptions options;
44 extern u_char *session_id2;
45 extern int session_id2_len;
47 Authctxt *x_authctxt = NULL;
51 extern Authmethod method_none;
52 extern Authmethod method_pubkey;
53 extern Authmethod method_passwd;
54 extern Authmethod method_kbdint;
55 extern Authmethod method_hostbased;
57 Authmethod *authmethods[] = {
68 static void input_service_request(int, u_int32_t, void *);
69 static void input_userauth_request(int, u_int32_t, void *);
72 static Authmethod *authmethod_lookup(const char *);
73 static char *authmethods_get(void);
74 int user_key_allowed(struct passwd *, Key *);
75 int hostbased_key_allowed(struct passwd *, const char *, char *, Key *);
78 * loop until authctxt->success == TRUE
82 do_authentication2(void)
84 Authctxt *authctxt = authctxt_new();
86 x_authctxt = authctxt; /*XXX*/
88 /* challenge-response is implemented via keyboard interactive */
89 if (options.challenge_response_authentication)
90 options.kbd_interactive_authentication = 1;
91 if (options.pam_authentication_via_kbd_int)
92 options.kbd_interactive_authentication = 1;
94 options.pam_authentication_via_kbd_int = 0;
96 dispatch_init(&dispatch_protocol_error);
97 dispatch_set(SSH2_MSG_SERVICE_REQUEST, &input_service_request);
98 dispatch_run(DISPATCH_BLOCK, &authctxt->success, authctxt);
104 input_service_request(int type, u_int32_t seq, void *ctxt)
106 Authctxt *authctxt = ctxt;
109 char *service = packet_get_string(&len);
112 if (authctxt == NULL)
113 fatal("input_service_request: no authctxt");
115 if (strcmp(service, "ssh-userauth") == 0) {
116 if (!authctxt->success) {
118 /* now we can handle user-auth requests */
119 dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &input_userauth_request);
122 /* XXX all other service requests are denied */
125 packet_start(SSH2_MSG_SERVICE_ACCEPT);
126 packet_put_cstring(service);
130 debug("bad service request %s", service);
131 packet_disconnect("bad service request %s", service);
137 input_userauth_request(int type, u_int32_t seq, void *ctxt)
139 Authctxt *authctxt = ctxt;
140 Authmethod *m = NULL;
141 char *user, *service, *method, *style = NULL;
142 int authenticated = 0;
143 #ifdef HAVE_LOGIN_CAP
145 const char *from_host, *from_ip;
147 from_host = get_canonical_hostname(options.verify_reverse_mapping);
148 from_ip = get_remote_ipaddr();
151 if (authctxt == NULL)
152 fatal("input_userauth_request: no authctxt");
154 user = packet_get_string(NULL);
155 service = packet_get_string(NULL);
156 method = packet_get_string(NULL);
157 debug("userauth-request for user %s service %s method %s", user, service, method);
158 debug("attempt %d failures %d", authctxt->attempt, authctxt->failures);
160 if ((style = strchr(user, ':')) != NULL)
163 if (authctxt->attempt++ == 0) {
164 /* setup auth context */
165 authctxt->pw = PRIVSEP(getpwnamallow(user));
166 if (authctxt->pw && strcmp(service, "ssh-connection")==0) {
168 debug2("input_userauth_request: setting up authctxt for %s", user);
170 PRIVSEP(start_pam(authctxt->pw->pw_name));
173 log("input_userauth_request: illegal user %s", user);
175 PRIVSEP(start_pam("NOUSER"));
178 setproctitle("%s%s", authctxt->pw ? user : "unknown",
179 use_privsep ? " [net]" : "");
180 authctxt->user = xstrdup(user);
181 authctxt->service = xstrdup(service);
182 authctxt->style = style ? xstrdup(style) : NULL;
184 mm_inform_authserv(service, style);
185 } else if (strcmp(user, authctxt->user) != 0 ||
186 strcmp(service, authctxt->service) != 0) {
187 packet_disconnect("Change of username or service not allowed: "
188 "(%s,%s) -> (%s,%s)",
189 authctxt->user, authctxt->service, user, service);
192 #ifdef HAVE_LOGIN_CAP
193 if (authctxt->pw != NULL) {
194 lc = login_getpwclass(authctxt->pw);
196 lc = login_getclassbyname(NULL, authctxt->pw);
197 if (!auth_hostok(lc, from_host, from_ip)) {
198 log("Denied connection for %.200s from %.200s [%.200s].",
199 authctxt->pw->pw_name, from_host, from_ip);
200 packet_disconnect("Sorry, you are not allowed to connect.");
202 if (!auth_timeok(lc, time(NULL))) {
203 log("LOGIN %.200s REFUSED (TIME) FROM %.200s",
204 authctxt->pw->pw_name, from_host);
205 packet_disconnect("Logins not available right now.");
210 #endif /* HAVE_LOGIN_CAP */
213 auth2_challenge_stop(authctxt);
214 authctxt->postponed = 0;
216 /* try to authenticate user */
217 m = authmethod_lookup(method);
219 debug2("input_userauth_request: try method %s", method);
220 authenticated = m->userauth(authctxt);
222 userauth_finish(authctxt, authenticated, method);
230 userauth_finish(Authctxt *authctxt, int authenticated, char *method)
234 if (!authctxt->valid && authenticated)
235 fatal("INTERNAL ERROR: authenticated invalid user %s",
238 /* Special handling for root */
240 authenticated && authctxt->pw->pw_uid == 0 &&
241 !auth_root_allowed(method))
245 if (!use_privsep && authenticated && authctxt->user &&
246 !do_pam_account(authctxt->user, NULL))
251 if (authenticated && cray_access_denied(authctxt->user)) {
253 fatal("Access denied for user %s.",authctxt->user);
257 /* Log before sending the reply */
258 auth_log(authctxt, authenticated, method, " ssh2");
260 if (authctxt->postponed)
263 /* XXX todo: check if multiple auth methods are needed */
264 if (authenticated == 1) {
265 /* turn off userauth */
266 dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &dispatch_protocol_ignore);
267 packet_start(SSH2_MSG_USERAUTH_SUCCESS);
270 /* now we can break out */
271 authctxt->success = 1;
273 if (authctxt->failures++ > AUTH_FAIL_MAX) {
274 packet_disconnect(AUTH_FAIL_MSG, authctxt->user);
277 if (strcmp(method, "password") == 0)
278 cray_login_failure(authctxt->user, IA_UDBERR);
280 methods = authmethods_get();
281 packet_start(SSH2_MSG_USERAUTH_FAILURE);
282 packet_put_cstring(methods);
283 packet_put_char(0); /* XXX partial success, unused */
290 /* get current user */
295 return (x_authctxt != NULL && x_authctxt->valid) ? x_authctxt->pw : NULL;
301 authmethods_get(void)
308 for (i = 0; authmethods[i] != NULL; i++) {
309 if (strcmp(authmethods[i]->name, "none") == 0)
311 if (authmethods[i]->enabled != NULL &&
312 *(authmethods[i]->enabled) != 0) {
313 if (buffer_len(&b) > 0)
314 buffer_append(&b, ",", 1);
315 buffer_append(&b, authmethods[i]->name,
316 strlen(authmethods[i]->name));
319 buffer_append(&b, "\0", 1);
320 list = xstrdup(buffer_ptr(&b));
326 authmethod_lookup(const char *name)
331 for (i = 0; authmethods[i] != NULL; i++)
332 if (authmethods[i]->enabled != NULL &&
333 *(authmethods[i]->enabled) != 0 &&
334 strcmp(name, authmethods[i]->name) == 0)
335 return authmethods[i];
336 debug2("Unrecognized authentication method name: %s",
337 name ? name : "NULL");