audit-bsm.c

   1 /* $Id: audit-bsm.c,v 1.5 2006/09/30 22:09:50 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 <stdarg.h>
  44 #include <unistd.h>
  45
  46 #include "ssh.h"
  47 #include "log.h"
  48 #include "key.h"
  49 #include "hostfile.h"
  50 #include "auth.h"
  51 #include "xmalloc.h"
  52
  53 #ifndef AUE_openssh
  54 # define AUE_openssh     32800
  55 #endif
  56 #include <bsm/audit.h>
  57 #include <bsm/libbsm.h>
  58 #include <bsm/audit_uevents.h>
  59 #include <bsm/audit_record.h>
  60 #include <locale.h>
  61
  62 #if defined(HAVE_GETAUDIT_ADDR)
  63 #define AuditInfoStruct         auditinfo_addr
  64 #define AuditInfoTermID         au_tid_addr_t
  65 #define GetAuditFunc(a,b)       getaudit_addr((a),(b))
  66 #define GetAuditFuncText        "getaudit_addr"
  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 GetAuditFunc(a,b)       getaudit(a)
  75 #define GetAuditFuncText        "getaudit"
  76 #define SetAuditFunc(a,b)       setaudit(a)
  77 #define SetAuditFuncText        "setaudit"
  78 #define AUToSubjectFunc         au_to_subject
  79 #define AUToReturnFunc(a,b)     au_to_return((a), (u_int)(b))
  80 #endif
  81
  82 extern int      cannot_audit(int);
  83 extern void     aug_init(void);
  84 extern dev_t    aug_get_port(void);
  85 extern int      aug_get_machine(char *, u_int32_t *, u_int32_t *);
  86 extern void     aug_save_auid(au_id_t);
  87 extern void     aug_save_uid(uid_t);
  88 extern void     aug_save_euid(uid_t);
  89 extern void     aug_save_gid(gid_t);
  90 extern void     aug_save_egid(gid_t);
  91 extern void     aug_save_pid(pid_t);
  92 extern void     aug_save_asid(au_asid_t);
  93 extern void     aug_save_tid(dev_t, unsigned int);
  94 extern void     aug_save_tid_ex(dev_t, u_int32_t *, u_int32_t);
  95 extern int      aug_save_me(void);
  96 extern int      aug_save_namask(void);
  97 extern void     aug_save_event(au_event_t);
  98 extern void     aug_save_sorf(int);
  99 extern void     aug_save_text(char *);
 100 extern void     aug_save_text1(char *);
 101 extern void     aug_save_text2(char *);
 102 extern void     aug_save_na(int);
 103 extern void     aug_save_user(char *);
 104 extern void     aug_save_path(char *);
 105 extern int      aug_save_policy(void);
 106 extern void     aug_save_afunc(int (*)(int));
 107 extern int      aug_audit(void);
 108 extern int      aug_na_selected(void);
 109 extern int      aug_selected(void);
 110 extern int      aug_daemon_session(void);
 111
 112 #ifndef HAVE_GETTEXT
 113 # define gettext(a)     (a)
 114 #endif
 115
 116 extern Authctxt *the_authctxt;
 117 static AuditInfoTermID ssh_bsm_tid;
 118
 119 /* Below is the low-level BSM interface code */
 120
 121 /*
 122  * Check if the specified event is selected (enabled) for auditing.
 123  * Returns 1 if the event is selected, 0 if not and -1 on failure.
 124  */
 125 static int
 126 selected(char *username, uid_t uid, au_event_t event, int sf)
 127 {
 128         int rc, sorf;
 129         char naflags[512];
 130         struct au_mask mask;
 131
 132         mask.am_success = mask.am_failure = 0;
 133         if (uid < 0) {
 134                 /* get flags for non-attributable (to a real user) events */
 135                 rc = getacna(naflags, sizeof(naflags));
 136                 if (rc == 0)
 137                         (void) getauditflagsbin(naflags, &mask);
 138         } else
 139                 rc = au_user_mask(username, &mask);
 140
 141         sorf = (sf == 0) ? AU_PRS_SUCCESS : AU_PRS_FAILURE;
 142         return(au_preselect(event, &mask, sorf, AU_PRS_REREAD));
 143 }
 144
 145 static void
 146 bsm_audit_record(int typ, char *string, au_event_t event_no)
 147 {
 148         int             ad, rc, sel;
 149         uid_t           uid = -1;
 150         gid_t           gid = -1;
 151         pid_t           pid = getpid();
 152         AuditInfoTermID tid = ssh_bsm_tid;
 153
 154         if (the_authctxt != NULL && the_authctxt->valid) {
 155                 uid = the_authctxt->pw->pw_uid;
 156                 gid = the_authctxt->pw->pw_gid;
 157         }
 158
 159         rc = (typ == 0) ? 0 : -1;
 160         sel = selected(the_authctxt->user, uid, event_no, rc);
 161         debug3("BSM audit: typ %d rc %d \"%s\"", typ, rc, string);
 162         if (!sel)
 163                 return; /* audit event does not match mask, do not write */
 164
 165         debug3("BSM audit: writing audit new record");
 166         ad = au_open();
 167
 168         (void) au_write(ad, AUToSubjectFunc(uid, uid, gid, uid, gid,
 169             pid, pid, &tid));
 170         (void) au_write(ad, au_to_text(string));
 171         (void) au_write(ad, AUToReturnFunc(typ, rc));
 172
 173         rc = au_close(ad, AU_TO_WRITE, event_no);
 174         if (rc < 0)
 175                 error("BSM audit: %s failed to write \"%s\" record: %s",
 176                     __func__, string, strerror(errno));
 177 }
 178
 179 static void
 180 bsm_audit_session_setup(void)
 181 {
 182         int rc;
 183         struct AuditInfoStruct info;
 184         au_mask_t mask;
 185
 186         if (the_authctxt == NULL) {
 187                 error("BSM audit: session setup internal error (NULL ctxt)");
 188                 return;
 189         }
 190
 191         if (the_authctxt->valid)
 192                 info.ai_auid = the_authctxt->pw->pw_uid;
 193         else
 194                 info.ai_auid = -1;
 195         info.ai_asid = getpid();
 196         mask.am_success = 0;
 197         mask.am_failure = 0;
 198
 199         (void) au_user_mask(the_authctxt->user, &mask);
 200
 201         info.ai_mask.am_success  = mask.am_success;
 202         info.ai_mask.am_failure  = mask.am_failure;
 203
 204         info.ai_termid = ssh_bsm_tid;
 205
 206         rc = SetAuditFunc(&info, sizeof(info));
 207         if (rc < 0)
 208                 error("BSM audit: %s: %s failed: %s", __func__,
 209                     SetAuditFuncText, strerror(errno));
 210 }
 211
 212 static void
 213 bsm_audit_bad_login(const char *what)
 214 {
 215         char textbuf[BSM_TEXTBUFSZ];
 216
 217         if (the_authctxt->valid) {
 218                 (void) snprintf(textbuf, sizeof (textbuf),
 219                         gettext("invalid %s for user %s"),
 220                             what, the_authctxt->user);
 221                 bsm_audit_record(4, textbuf, AUE_openssh);
 222         } else {
 223                 (void) snprintf(textbuf, sizeof (textbuf),
 224                         gettext("invalid user name \"%s\""),
 225                             the_authctxt->user);
 226                 bsm_audit_record(3, textbuf, AUE_openssh);
 227         }
 228 }
 229
 230 /* Below is the sshd audit API code */
 231
 232 void
 233 audit_connection_from(const char *host, int port)
 234 {
 235         AuditInfoTermID *tid = &ssh_bsm_tid;
 236         char buf[1024];
 237
 238         if (cannot_audit(0))
 239                 return;
 240         debug3("BSM audit: connection from %.100s port %d", host, port);
 241
 242         /* populate our terminal id structure */
 243 #if defined(HAVE_GETAUDIT_ADDR)
 244         tid->at_port = (dev_t)port;
 245         aug_get_machine((char *)host, &(tid->at_addr[0]), &(tid->at_type));
 246         snprintf(buf, sizeof(buf), "%08x %08x %08x %08x", tid->at_addr[0],
 247             tid->at_addr[1], tid->at_addr[2], tid->at_addr[3]);
 248         debug3("BSM audit: iptype %d machine ID %s", (int)tid->at_type, buf);
 249 #else
 250         /* this is used on IPv4-only machines */
 251         tid->port = (dev_t)port;
 252         tid->machine = inet_addr(host);
 253         snprintf(buf, sizeof(buf), "%08x", tid->machine);
 254         debug3("BSM audit: machine ID %s", buf);
 255 #endif
 256 }
 257
 258 void
 259 audit_run_command(const char *command)
 260 {
 261         /* not implemented */
 262 }
 263
 264 void
 265 audit_session_open(const char *ttyn)
 266 {
 267         /* not implemented */
 268 }
 269
 270 void
 271 audit_session_close(const char *ttyn)
 272 {
 273         /* not implemented */
 274 }
 275
 276 void
 277 audit_event(ssh_audit_event_t event)
 278 {
 279         char    textbuf[BSM_TEXTBUFSZ];
 280         static int logged_in = 0;
 281         const char *user = the_authctxt ? the_authctxt->user : "(unknown user)";
 282
 283         if (cannot_audit(0))
 284                 return;
 285
 286         switch(event) {
 287         case SSH_AUTH_SUCCESS:
 288                 logged_in = 1;
 289                 bsm_audit_session_setup();
 290                 snprintf(textbuf, sizeof(textbuf),
 291                     gettext("successful login %s"), user);
 292                 bsm_audit_record(0, textbuf, AUE_openssh);
 293                 break;
 294
 295         case SSH_CONNECTION_CLOSE:
 296                 /*
 297                  * We can also get a close event if the user attempted auth
 298                  * but never succeeded.
 299                  */
 300                 if (logged_in) {
 301                         snprintf(textbuf, sizeof(textbuf),
 302                             gettext("sshd logout %s"), the_authctxt->user);
 303                         bsm_audit_record(0, textbuf, AUE_logout);
 304                 } else {
 305                         debug("%s: connection closed without authentication",
 306                             __func__);
 307                 }
 308                 break;
 309
 310         case SSH_NOLOGIN:
 311                 bsm_audit_record(1,
 312                     gettext("logins disabled by /etc/nologin"), AUE_openssh);
 313                 break;
 314
 315         case SSH_LOGIN_EXCEED_MAXTRIES:
 316                 snprintf(textbuf, sizeof(textbuf),
 317                     gettext("too many tries for user %s"), the_authctxt->user);
 318                 bsm_audit_record(1, textbuf, AUE_openssh);
 319                 break;
 320
 321         case SSH_LOGIN_ROOT_DENIED:
 322                 bsm_audit_record(2, gettext("not_console"), AUE_openssh);
 323                 break;
 324
 325         case SSH_AUTH_FAIL_PASSWD:
 326                 bsm_audit_bad_login("password");
 327                 break;
 328
 329         case SSH_AUTH_FAIL_KBDINT:
 330                 bsm_audit_bad_login("interactive password entry");
 331                 break;
 332
 333         default:
 334                 debug("%s: unhandled event %d", __func__, event);
 335         }
 336 }
 337 #endif /* BSM */