1 /*
2 * TODO
3 *
4 * - deal with overlap between this and sys_auth_allowed_user
5 * sys_auth_record_login and record_failed_login.
6 */
7
8 /*
9 * Copyright 1988-2002 Sun Microsystems, Inc. All rights reserved.
10 * Use is subject to license terms.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 *
32 */
33 /* #pragma ident "@(#)bsmaudit.c 1.1 01/09/17 SMI" */
34
35 #include "includes.h"
36 #if defined(USE_BSM_AUDIT)
37
38 #include <sys/types.h>
39
40 #include <errno.h>
41 #include <netdb.h>
42 #include <stdarg.h>
43 #include <string.h>
44 #include <unistd.h>
45
46 #ifdef BROKEN_BSM_API
47 #include <libscf.h>
48 #endif
49
50 #include "ssh.h"
51 #include "log.h"
52 #include "hostfile.h"
53 #include "auth.h"
54 #include "xmalloc.h"
55
56 #ifndef AUE_openssh
57 # define AUE_openssh 32800
58 #endif
59 #include <bsm/audit.h>
60 #include <bsm/libbsm.h>
61 #include <bsm/audit_uevents.h>
62 #include <bsm/audit_record.h>
63 #include <locale.h>
64
65 #if defined(HAVE_GETAUDIT_ADDR)
66 #define AuditInfoStruct auditinfo_addr
67 #define AuditInfoTermID au_tid_addr_t
68 #define SetAuditFunc(a,b) setaudit_addr((a),(b))
69 #define SetAuditFuncText "setaudit_addr"
70 #define AUToSubjectFunc au_to_subject_ex
71 #define AUToReturnFunc(a,b) au_to_return32((a), (int32_t)(b))
72 #else
73 #define AuditInfoStruct auditinfo
74 #define AuditInfoTermID au_tid_t
75 #define SetAuditFunc(a,b) setaudit(a)
76 #define SetAuditFuncText "setaudit"
77 #define AUToSubjectFunc au_to_subject
78 #define AUToReturnFunc(a,b) au_to_return((a), (u_int)(b))
79 #endif
80
81 #ifndef cannot_audit
82 extern int cannot_audit(int);
83 #endif
84 extern void aug_init(void);
85 extern void aug_save_auid(au_id_t);
86 extern void aug_save_uid(uid_t);
87 extern void aug_save_euid(uid_t);
88 extern void aug_save_gid(gid_t);
89 extern void aug_save_egid(gid_t);
90 extern void aug_save_pid(pid_t);
91 extern void aug_save_asid(au_asid_t);
92 extern void aug_save_tid(dev_t, unsigned int);
93 extern void aug_save_tid_ex(dev_t, u_int32_t *, u_int32_t);
94 extern int aug_save_me(void);
95 extern int aug_save_namask(void);
96 extern void aug_save_event(au_event_t);
97 extern void aug_save_sorf(int);
98 extern void aug_save_text(char *);
99 extern void aug_save_text1(char *);
100 extern void aug_save_text2(char *);
101 extern void aug_save_na(int);
102 extern void aug_save_user(char *);
103 extern void aug_save_path(char *);
104 extern int aug_save_policy(void);
105 extern void aug_save_afunc(int (*)(int));
106 extern int aug_audit(void);
107 extern int aug_na_selected(void);
108 extern int aug_selected(void);
109 extern int aug_daemon_session(void);
110
111 #ifndef HAVE_GETTEXT
112 # define gettext(a) (a)
113 #endif
114
115 extern Authctxt *the_authctxt;
116 static AuditInfoTermID ssh_bsm_tid;
117
118 #ifdef BROKEN_BSM_API
119 /* For some reason this constant is no longer defined
120 in Solaris 11. */
121 #define BSM_TEXTBUFSZ 256
122 #endif
123
124 /* Below is the low-level BSM interface code */
125
126 /*
127 * aug_get_machine is only required on IPv6 capable machines, we use a
128 * different mechanism in audit_connection_from() for IPv4-only machines.
129 * getaudit_addr() is only present on IPv6 capable machines.
130 */
131 #if defined(HAVE_AUG_GET_MACHINE) || !defined(HAVE_GETAUDIT_ADDR)
132 extern int aug_get_machine(char *, u_int32_t *, u_int32_t *);
133 #else
134 static int
aug_get_machine(char * host,u_int32_t * addr,u_int32_t * type)135 aug_get_machine(char *host, u_int32_t *addr, u_int32_t *type)
136 {
137 struct addrinfo *ai;
138 struct sockaddr_in *in4;
139 struct sockaddr_in6 *in6;
140 int ret = 0, r;
141
142 if ((r = getaddrinfo(host, NULL, NULL, &ai)) != 0) {
143 error("BSM audit: getaddrinfo failed for %.100s: %.100s", host,
144 r == EAI_SYSTEM ? strerror(errno) : gai_strerror(r));
145 return -1;
146 }
147
148 switch (ai->ai_family) {
149 case AF_INET:
150 in4 = (struct sockaddr_in *)ai->ai_addr;
151 *type = AU_IPv4;
152 memcpy(addr, &in4->sin_addr, sizeof(struct in_addr));
153 break;
154 #ifdef AU_IPv6
155 case AF_INET6:
156 in6 = (struct sockaddr_in6 *)ai->ai_addr;
157 *type = AU_IPv6;
158 memcpy(addr, &in6->sin6_addr, sizeof(struct in6_addr));
159 break;
160 #endif
161 default:
162 error("BSM audit: unknown address family for %.100s: %d",
163 host, ai->ai_family);
164 ret = -1;
165 }
166 freeaddrinfo(ai);
167 return ret;
168 }
169 #endif
170
171 #ifdef BROKEN_BSM_API
172 /*
173 In Solaris 11 the audit daemon has been moved to SMF. In the process
174 they simply dropped getacna() from the API, since it read from a now
175 non-existent config file. This function re-implements getacna() to
176 read from the SMF repository instead.
177 */
178 int
getacna(char * auditstring,int len)179 getacna(char *auditstring, int len)
180 {
181 scf_handle_t *handle = NULL;
182 scf_property_t *property = NULL;
183 scf_value_t *value = NULL;
184 int ret = 0;
185
186 /*
187 * The man page for getacna on Solaris 10 states we should return -2
188 * in case of error and set errno to indicate the error. We don't
189 * bother with errno here, though, since the only use of this function
190 * below doesn't check for errors anyway.
191 */
192 handle = scf_handle_create(SCF_VERSION);
193 if (handle == NULL)
194 return -2;
195
196 ret = scf_handle_bind(handle);
197 if (ret == -1)
198 return -2;
199
200 property = scf_property_create(handle);
201 if (property == NULL)
202 return -2;
203
204 ret = scf_handle_decode_fmri(handle,
205 "svc:/system/auditd:default/:properties/preselection/naflags",
206 NULL, NULL, NULL, NULL, property, 0);
207 if (ret == -1)
208 return -2;
209
210 value = scf_value_create(handle);
211 if (value == NULL)
212 return -2;
213
214 ret = scf_property_get_value(property, value);
215 if (ret == -1)
216 return -2;
217
218 ret = scf_value_get_astring(value, auditstring, len);
219 if (ret == -1)
220 return -2;
221
222 scf_value_destroy(value);
223 scf_property_destroy(property);
224 scf_handle_destroy(handle);
225
226 return 0;
227 }
228 #endif
229
230 /*
231 * Check if the specified event is selected (enabled) for auditing.
232 * Returns 1 if the event is selected, 0 if not and -1 on failure.
233 */
234 static int
selected(char * username,uid_t uid,au_event_t event,int sf)235 selected(char *username, uid_t uid, au_event_t event, int sf)
236 {
237 int rc, sorf;
238 char naflags[512];
239 struct au_mask mask;
240
241 mask.am_success = mask.am_failure = 0;
242 if (uid < 0) {
243 /* get flags for non-attributable (to a real user) events */
244 rc = getacna(naflags, sizeof(naflags));
245 if (rc == 0)
246 (void) getauditflagsbin(naflags, &mask);
247 } else
248 rc = au_user_mask(username, &mask);
249
250 sorf = (sf == 0) ? AU_PRS_SUCCESS : AU_PRS_FAILURE;
251 return(au_preselect(event, &mask, sorf, AU_PRS_REREAD));
252 }
253
254 static void
bsm_audit_record(int typ,char * string,au_event_t event_no)255 bsm_audit_record(int typ, char *string, au_event_t event_no)
256 {
257 int ad, rc, sel;
258 uid_t uid = -1;
259 gid_t gid = -1;
260 pid_t pid = getpid();
261 AuditInfoTermID tid = ssh_bsm_tid;
262
263 if (the_authctxt != NULL && the_authctxt->valid) {
264 uid = the_authctxt->pw->pw_uid;
265 gid = the_authctxt->pw->pw_gid;
266 }
267
268 rc = (typ == 0) ? 0 : -1;
269 sel = selected(the_authctxt->user, uid, event_no, rc);
270 debug3("BSM audit: typ %d rc %d \"%s\"", typ, rc, string);
271 if (!sel)
272 return; /* audit event does not match mask, do not write */
273
274 debug3("BSM audit: writing audit new record");
275 ad = au_open();
276
277 (void) au_write(ad, AUToSubjectFunc(uid, uid, gid, uid, gid,
278 pid, pid, &tid));
279 (void) au_write(ad, au_to_text(string));
280 (void) au_write(ad, AUToReturnFunc(typ, rc));
281
282 #ifdef BROKEN_BSM_API
283 /*
284 * The last argument is the event modifier flags. For some seemingly
285 * undocumented reason it was added in Solaris 11.
286 */
287 rc = au_close(ad, AU_TO_WRITE, event_no, 0);
288 #else
289 rc = au_close(ad, AU_TO_WRITE, event_no);
290 #endif
291
292 if (rc < 0)
293 error("BSM audit: %s failed to write \"%s\" record: %s",
294 __func__, string, strerror(errno));
295 }
296
297 static void
bsm_audit_session_setup(void)298 bsm_audit_session_setup(void)
299 {
300 int rc;
301 struct AuditInfoStruct info;
302 au_mask_t mask;
303
304 if (the_authctxt == NULL) {
305 error("BSM audit: session setup internal error (NULL ctxt)");
306 return;
307 }
308
309 if (the_authctxt->valid)
310 info.ai_auid = the_authctxt->pw->pw_uid;
311 else
312 info.ai_auid = -1;
313 info.ai_asid = getpid();
314 mask.am_success = 0;
315 mask.am_failure = 0;
316
317 (void) au_user_mask(the_authctxt->user, &mask);
318
319 info.ai_mask.am_success = mask.am_success;
320 info.ai_mask.am_failure = mask.am_failure;
321
322 info.ai_termid = ssh_bsm_tid;
323
324 rc = SetAuditFunc(&info, sizeof(info));
325 if (rc < 0)
326 error("BSM audit: %s: %s failed: %s", __func__,
327 SetAuditFuncText, strerror(errno));
328 }
329
330 static void
bsm_audit_bad_login(const char * what)331 bsm_audit_bad_login(const char *what)
332 {
333 char textbuf[BSM_TEXTBUFSZ];
334
335 if (the_authctxt->valid) {
336 (void) snprintf(textbuf, sizeof (textbuf),
337 gettext("invalid %s for user %s"),
338 what, the_authctxt->user);
339 bsm_audit_record(4, textbuf, AUE_openssh);
340 } else {
341 (void) snprintf(textbuf, sizeof (textbuf),
342 gettext("invalid user name \"%s\""),
343 the_authctxt->user);
344 bsm_audit_record(3, textbuf, AUE_openssh);
345 }
346 }
347
348 /* Below is the sshd audit API code */
349
350 void
audit_connection_from(const char * host,int port)351 audit_connection_from(const char *host, int port)
352 {
353 AuditInfoTermID *tid = &ssh_bsm_tid;
354 char buf[1024];
355
356 if (cannot_audit(0))
357 return;
358 debug3("BSM audit: connection from %.100s port %d", host, port);
359
360 /* populate our terminal id structure */
361 #if defined(HAVE_GETAUDIT_ADDR)
362 tid->at_port = (dev_t)port;
363 aug_get_machine((char *)host, &(tid->at_addr[0]), &(tid->at_type));
364 snprintf(buf, sizeof(buf), "%08x %08x %08x %08x", tid->at_addr[0],
365 tid->at_addr[1], tid->at_addr[2], tid->at_addr[3]);
366 debug3("BSM audit: iptype %d machine ID %s", (int)tid->at_type, buf);
367 #else
368 /* this is used on IPv4-only machines */
369 tid->port = (dev_t)port;
370 tid->machine = inet_addr(host);
371 snprintf(buf, sizeof(buf), "%08x", tid->machine);
372 debug3("BSM audit: machine ID %s", buf);
373 #endif
374 }
375
376 void
audit_run_command(const char * command)377 audit_run_command(const char *command)
378 {
379 /* not implemented */
380 }
381
382 void
audit_session_open(struct logininfo * li)383 audit_session_open(struct logininfo *li)
384 {
385 /* not implemented */
386 }
387
388 void
audit_session_close(struct logininfo * li)389 audit_session_close(struct logininfo *li)
390 {
391 /* not implemented */
392 }
393
394 void
audit_event(struct ssh * ssh,ssh_audit_event_t event)395 audit_event(struct ssh *ssh, ssh_audit_event_t event)
396 {
397 char textbuf[BSM_TEXTBUFSZ];
398 static int logged_in = 0;
399 const char *user = the_authctxt ? the_authctxt->user : "(unknown user)";
400
401 if (cannot_audit(0))
402 return;
403
404 switch(event) {
405 case SSH_AUTH_SUCCESS:
406 logged_in = 1;
407 bsm_audit_session_setup();
408 snprintf(textbuf, sizeof(textbuf),
409 gettext("successful login %s"), user);
410 bsm_audit_record(0, textbuf, AUE_openssh);
411 break;
412
413 case SSH_CONNECTION_CLOSE:
414 /*
415 * We can also get a close event if the user attempted auth
416 * but never succeeded.
417 */
418 if (logged_in) {
419 snprintf(textbuf, sizeof(textbuf),
420 gettext("sshd logout %s"), the_authctxt->user);
421 bsm_audit_record(0, textbuf, AUE_logout);
422 } else {
423 debug("%s: connection closed without authentication",
424 __func__);
425 }
426 break;
427
428 case SSH_NOLOGIN:
429 bsm_audit_record(1,
430 gettext("logins disabled by /etc/nologin"), AUE_openssh);
431 break;
432
433 case SSH_LOGIN_EXCEED_MAXTRIES:
434 snprintf(textbuf, sizeof(textbuf),
435 gettext("too many tries for user %s"), the_authctxt->user);
436 bsm_audit_record(1, textbuf, AUE_openssh);
437 break;
438
439 case SSH_LOGIN_ROOT_DENIED:
440 bsm_audit_record(2, gettext("not_console"), AUE_openssh);
441 break;
442
443 case SSH_AUTH_FAIL_PASSWD:
444 bsm_audit_bad_login("password");
445 break;
446
447 case SSH_AUTH_FAIL_KBDINT:
448 bsm_audit_bad_login("interactive password entry");
449 break;
450
451 default:
452 debug("%s: unhandled event %d", __func__, event);
453 }
454 }
455 #endif /* BSM */
456