1 /* $Id: audit-bsm.c,v 1.6 2008/02/25 10:05:04 dtucker Exp $ */ 2 3 /* 4 * TODO 5 * 6 * - deal with overlap between this and sys_auth_allowed_user 7 * sys_auth_record_login and record_failed_login. 8 */ 9 10 /* 11 * Copyright 1988-2002 Sun Microsystems, Inc. All rights reserved. 12 * Use is subject to license terms. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 26 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 33 * 34 */ 35 /* #pragma ident "@(#)bsmaudit.c 1.1 01/09/17 SMI" */ 36 37 #include "includes.h" 38 #if defined(USE_BSM_AUDIT) 39 40 #include <sys/types.h> 41 42 #include <errno.h> 43 #include <netdb.h> 44 #include <stdarg.h> 45 #include <string.h> 46 #include <unistd.h> 47 48 #include "ssh.h" 49 #include "log.h" 50 #include "key.h" 51 #include "hostfile.h" 52 #include "auth.h" 53 #include "xmalloc.h" 54 55 #ifndef AUE_openssh 56 # define AUE_openssh 32800 57 #endif 58 #include <bsm/audit.h> 59 #include <bsm/libbsm.h> 60 #include <bsm/audit_uevents.h> 61 #include <bsm/audit_record.h> 62 #include <locale.h> 63 64 #if defined(HAVE_GETAUDIT_ADDR) 65 #define AuditInfoStruct auditinfo_addr 66 #define AuditInfoTermID au_tid_addr_t 67 #define SetAuditFunc(a,b) setaudit_addr((a),(b)) 68 #define SetAuditFuncText "setaudit_addr" 69 #define AUToSubjectFunc au_to_subject_ex 70 #define AUToReturnFunc(a,b) au_to_return32((a), (int32_t)(b)) 71 #else 72 #define AuditInfoStruct auditinfo 73 #define AuditInfoTermID au_tid_t 74 #define SetAuditFunc(a,b) setaudit(a) 75 #define SetAuditFuncText "setaudit" 76 #define AUToSubjectFunc au_to_subject 77 #define AUToReturnFunc(a,b) au_to_return((a), (u_int)(b)) 78 #endif 79 80 #ifndef cannot_audit 81 extern int cannot_audit(int); 82 #endif 83 extern void aug_init(void); 84 extern void aug_save_auid(au_id_t); 85 extern void aug_save_uid(uid_t); 86 extern void aug_save_euid(uid_t); 87 extern void aug_save_gid(gid_t); 88 extern void aug_save_egid(gid_t); 89 extern void aug_save_pid(pid_t); 90 extern void aug_save_asid(au_asid_t); 91 extern void aug_save_tid(dev_t, unsigned int); 92 extern void aug_save_tid_ex(dev_t, u_int32_t *, u_int32_t); 93 extern int aug_save_me(void); 94 extern int aug_save_namask(void); 95 extern void aug_save_event(au_event_t); 96 extern void aug_save_sorf(int); 97 extern void aug_save_text(char *); 98 extern void aug_save_text1(char *); 99 extern void aug_save_text2(char *); 100 extern void aug_save_na(int); 101 extern void aug_save_user(char *); 102 extern void aug_save_path(char *); 103 extern int aug_save_policy(void); 104 extern void aug_save_afunc(int (*)(int)); 105 extern int aug_audit(void); 106 extern int aug_na_selected(void); 107 extern int aug_selected(void); 108 extern int aug_daemon_session(void); 109 110 #ifndef HAVE_GETTEXT 111 # define gettext(a) (a) 112 #endif 113 114 extern Authctxt *the_authctxt; 115 static AuditInfoTermID ssh_bsm_tid; 116 117 /* Below is the low-level BSM interface code */ 118 119 /* 120 * aug_get_machine is only required on IPv6 capable machines, we use a 121 * different mechanism in audit_connection_from() for IPv4-only machines. 122 * getaudit_addr() is only present on IPv6 capable machines. 123 */ 124 #if defined(HAVE_AUG_GET_MACHINE) || !defined(HAVE_GETAUDIT_ADDR) 125 extern int aug_get_machine(char *, u_int32_t *, u_int32_t *); 126 #else 127 static int 128 aug_get_machine(char *host, u_int32_t *addr, u_int32_t *type) 129 { 130 struct addrinfo *ai; 131 struct sockaddr_in *in4; 132 struct sockaddr_in6 *in6; 133 int ret = 0, r; 134 135 if ((r = getaddrinfo(host, NULL, NULL, &ai)) != 0) { 136 error("BSM audit: getaddrinfo failed for %.100s: %.100s", host, 137 r == EAI_SYSTEM ? strerror(errno) : gai_strerror(r)); 138 return -1; 139 } 140 141 switch (ai->ai_family) { 142 case AF_INET: 143 in4 = (struct sockaddr_in *)ai->ai_addr; 144 *type = AU_IPv4; 145 memcpy(addr, &in4->sin_addr, sizeof(struct in_addr)); 146 break; 147 #ifdef AU_IPv6 148 case AF_INET6: 149 in6 = (struct sockaddr_in6 *)ai->ai_addr; 150 *type = AU_IPv6; 151 memcpy(addr, &in6->sin6_addr, sizeof(struct in6_addr)); 152 break; 153 #endif 154 default: 155 error("BSM audit: unknown address family for %.100s: %d", 156 host, ai->ai_family); 157 ret = -1; 158 } 159 freeaddrinfo(ai); 160 return ret; 161 } 162 #endif 163 164 /* 165 * Check if the specified event is selected (enabled) for auditing. 166 * Returns 1 if the event is selected, 0 if not and -1 on failure. 167 */ 168 static int 169 selected(char *username, uid_t uid, au_event_t event, int sf) 170 { 171 int rc, sorf; 172 char naflags[512]; 173 struct au_mask mask; 174 175 mask.am_success = mask.am_failure = 0; 176 if (uid < 0) { 177 /* get flags for non-attributable (to a real user) events */ 178 rc = getacna(naflags, sizeof(naflags)); 179 if (rc == 0) 180 (void) getauditflagsbin(naflags, &mask); 181 } else 182 rc = au_user_mask(username, &mask); 183 184 sorf = (sf == 0) ? AU_PRS_SUCCESS : AU_PRS_FAILURE; 185 return(au_preselect(event, &mask, sorf, AU_PRS_REREAD)); 186 } 187 188 static void 189 bsm_audit_record(int typ, char *string, au_event_t event_no) 190 { 191 int ad, rc, sel; 192 uid_t uid = -1; 193 gid_t gid = -1; 194 pid_t pid = getpid(); 195 AuditInfoTermID tid = ssh_bsm_tid; 196 197 if (the_authctxt != NULL && the_authctxt->valid) { 198 uid = the_authctxt->pw->pw_uid; 199 gid = the_authctxt->pw->pw_gid; 200 } 201 202 rc = (typ == 0) ? 0 : -1; 203 sel = selected(the_authctxt->user, uid, event_no, rc); 204 debug3("BSM audit: typ %d rc %d \"%s\"", typ, rc, string); 205 if (!sel) 206 return; /* audit event does not match mask, do not write */ 207 208 debug3("BSM audit: writing audit new record"); 209 ad = au_open(); 210 211 (void) au_write(ad, AUToSubjectFunc(uid, uid, gid, uid, gid, 212 pid, pid, &tid)); 213 (void) au_write(ad, au_to_text(string)); 214 (void) au_write(ad, AUToReturnFunc(typ, rc)); 215 216 rc = au_close(ad, AU_TO_WRITE, event_no); 217 if (rc < 0) 218 error("BSM audit: %s failed to write \"%s\" record: %s", 219 __func__, string, strerror(errno)); 220 } 221 222 static void 223 bsm_audit_session_setup(void) 224 { 225 int rc; 226 struct AuditInfoStruct info; 227 au_mask_t mask; 228 229 if (the_authctxt == NULL) { 230 error("BSM audit: session setup internal error (NULL ctxt)"); 231 return; 232 } 233 234 if (the_authctxt->valid) 235 info.ai_auid = the_authctxt->pw->pw_uid; 236 else 237 info.ai_auid = -1; 238 info.ai_asid = getpid(); 239 mask.am_success = 0; 240 mask.am_failure = 0; 241 242 (void) au_user_mask(the_authctxt->user, &mask); 243 244 info.ai_mask.am_success = mask.am_success; 245 info.ai_mask.am_failure = mask.am_failure; 246 247 info.ai_termid = ssh_bsm_tid; 248 249 rc = SetAuditFunc(&info, sizeof(info)); 250 if (rc < 0) 251 error("BSM audit: %s: %s failed: %s", __func__, 252 SetAuditFuncText, strerror(errno)); 253 } 254 255 static void 256 bsm_audit_bad_login(const char *what) 257 { 258 char textbuf[BSM_TEXTBUFSZ]; 259 260 if (the_authctxt->valid) { 261 (void) snprintf(textbuf, sizeof (textbuf), 262 gettext("invalid %s for user %s"), 263 what, the_authctxt->user); 264 bsm_audit_record(4, textbuf, AUE_openssh); 265 } else { 266 (void) snprintf(textbuf, sizeof (textbuf), 267 gettext("invalid user name \"%s\""), 268 the_authctxt->user); 269 bsm_audit_record(3, textbuf, AUE_openssh); 270 } 271 } 272 273 /* Below is the sshd audit API code */ 274 275 void 276 audit_connection_from(const char *host, int port) 277 { 278 AuditInfoTermID *tid = &ssh_bsm_tid; 279 char buf[1024]; 280 281 if (cannot_audit(0)) 282 return; 283 debug3("BSM audit: connection from %.100s port %d", host, port); 284 285 /* populate our terminal id structure */ 286 #if defined(HAVE_GETAUDIT_ADDR) 287 tid->at_port = (dev_t)port; 288 aug_get_machine((char *)host, &(tid->at_addr[0]), &(tid->at_type)); 289 snprintf(buf, sizeof(buf), "%08x %08x %08x %08x", tid->at_addr[0], 290 tid->at_addr[1], tid->at_addr[2], tid->at_addr[3]); 291 debug3("BSM audit: iptype %d machine ID %s", (int)tid->at_type, buf); 292 #else 293 /* this is used on IPv4-only machines */ 294 tid->port = (dev_t)port; 295 tid->machine = inet_addr(host); 296 snprintf(buf, sizeof(buf), "%08x", tid->machine); 297 debug3("BSM audit: machine ID %s", buf); 298 #endif 299 } 300 301 void 302 audit_run_command(const char *command) 303 { 304 /* not implemented */ 305 } 306 307 void 308 audit_session_open(const char *ttyn) 309 { 310 /* not implemented */ 311 } 312 313 void 314 audit_session_close(const char *ttyn) 315 { 316 /* not implemented */ 317 } 318 319 void 320 audit_event(ssh_audit_event_t event) 321 { 322 char textbuf[BSM_TEXTBUFSZ]; 323 static int logged_in = 0; 324 const char *user = the_authctxt ? the_authctxt->user : "(unknown user)"; 325 326 if (cannot_audit(0)) 327 return; 328 329 switch(event) { 330 case SSH_AUTH_SUCCESS: 331 logged_in = 1; 332 bsm_audit_session_setup(); 333 snprintf(textbuf, sizeof(textbuf), 334 gettext("successful login %s"), user); 335 bsm_audit_record(0, textbuf, AUE_openssh); 336 break; 337 338 case SSH_CONNECTION_CLOSE: 339 /* 340 * We can also get a close event if the user attempted auth 341 * but never succeeded. 342 */ 343 if (logged_in) { 344 snprintf(textbuf, sizeof(textbuf), 345 gettext("sshd logout %s"), the_authctxt->user); 346 bsm_audit_record(0, textbuf, AUE_logout); 347 } else { 348 debug("%s: connection closed without authentication", 349 __func__); 350 } 351 break; 352 353 case SSH_NOLOGIN: 354 bsm_audit_record(1, 355 gettext("logins disabled by /etc/nologin"), AUE_openssh); 356 break; 357 358 case SSH_LOGIN_EXCEED_MAXTRIES: 359 snprintf(textbuf, sizeof(textbuf), 360 gettext("too many tries for user %s"), the_authctxt->user); 361 bsm_audit_record(1, textbuf, AUE_openssh); 362 break; 363 364 case SSH_LOGIN_ROOT_DENIED: 365 bsm_audit_record(2, gettext("not_console"), AUE_openssh); 366 break; 367 368 case SSH_AUTH_FAIL_PASSWD: 369 bsm_audit_bad_login("password"); 370 break; 371 372 case SSH_AUTH_FAIL_KBDINT: 373 bsm_audit_bad_login("interactive password entry"); 374 break; 375 376 default: 377 debug("%s: unhandled event %d", __func__, event); 378 } 379 } 380 #endif /* BSM */ 381