audit-bsm.c

   1 /* $Id: audit-bsm.c,v 1.3 2006/08/16 01:40:45 djm 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 <unistd.h>
  43
  44 #include "ssh.h"
  45 #include "log.h"
  46 #include "key.h"
  47 #include "hostfile.h"
  48 #include "auth.h"
  49 #include "xmalloc.h"
  50
  51 #ifndef AUE_openssh
  52 # define AUE_openssh     32800
  53 #endif
  54 #include <bsm/audit.h>
  55 #include <bsm/libbsm.h>
  56 #include <bsm/audit_uevents.h>
  57 #include <bsm/audit_record.h>
  58 #include <locale.h>
  59
  60 #if defined(HAVE_GETAUDIT_ADDR)
  61 #define AuditInfoStruct         auditinfo_addr
  62 #define AuditInfoTermID         au_tid_addr_t
  63 #define GetAuditFunc(a,b)       getaudit_addr((a),(b))
  64 #define GetAuditFuncText        "getaudit_addr"
  65 #define SetAuditFunc(a,b)       setaudit_addr((a),(b))
  66 #define SetAuditFuncText        "setaudit_addr"
  67 #define AUToSubjectFunc         au_to_subject_ex
  68 #define AUToReturnFunc(a,b)     au_to_return32((a), (int32_t)(b))
  69 #else
  70 #define AuditInfoStruct         auditinfo
  71 #define AuditInfoTermID         au_tid_t
  72 #define GetAuditFunc(a,b)       getaudit(a)
  73 #define GetAuditFuncText        "getaudit"
  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 extern int      cannot_audit(int);
  81 extern void     aug_init(void);
  82 extern dev_t    aug_get_port(void);
  83 extern int      aug_get_machine(char *, u_int32_t *, u_int32_t *);
  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  * Check if the specified event is selected (enabled) for auditing.
 121  * Returns 1 if the event is selected, 0 if not and -1 on failure.
 122  */
 123 static int
 124 selected(char *username, uid_t uid, au_event_t event, int sf)
 125 {
 126         int rc, sorf;
 127         char naflags[512];
 128         struct au_mask mask;
 129
 130         mask.am_success = mask.am_failure = 0;
 131         if (uid < 0) {
 132                 /* get flags for non-attributable (to a real user) events */
 133                 rc = getacna(naflags, sizeof(naflags));
 134                 if (rc == 0)
 135                         (void) getauditflagsbin(naflags, &mask);
 136         } else
 137                 rc = au_user_mask(username, &mask);
 138
 139         sorf = (sf == 0) ? AU_PRS_SUCCESS : AU_PRS_FAILURE;
 140         return(au_preselect(event, &mask, sorf, AU_PRS_REREAD));
 141 }
 142
 143 static void
 144 bsm_audit_record(int typ, char *string, au_event_t event_no)
 145 {
 146         int             ad, rc, sel;
 147         uid_t           uid = -1;
 148         gid_t           gid = -1;
 149         pid_t           pid = getpid();
 150         AuditInfoTermID tid = ssh_bsm_tid;
 151
 152         if (the_authctxt != NULL && the_authctxt->valid) {
 153                 uid = the_authctxt->pw->pw_uid;
 154                 gid = the_authctxt->pw->pw_gid;
 155         }
 156
 157         rc = (typ == 0) ? 0 : -1;
 158         sel = selected(the_authctxt->user, uid, event_no, rc);
 159         debug3("BSM audit: typ %d rc %d \"%s\"", typ, rc, string);
 160         if (!sel)
 161                 return; /* audit event does not match mask, do not write */
 162
 163         debug3("BSM audit: writing audit new record");
 164         ad = au_open();
 165
 166         (void) au_write(ad, AUToSubjectFunc(uid, uid, gid, uid, gid,
 167             pid, pid, &tid));
 168         (void) au_write(ad, au_to_text(string));
 169         (void) au_write(ad, AUToReturnFunc(typ, rc));
 170
 171         rc = au_close(ad, AU_TO_WRITE, event_no);
 172         if (rc < 0)
 173                 error("BSM audit: %s failed to write \"%s\" record: %s",
 174                     __func__, string, strerror(errno));
 175 }
 176
 177 static void
 178 bsm_audit_session_setup(void)
 179 {
 180         int rc;
 181         struct AuditInfoStruct info;
 182         au_mask_t mask;
 183
 184         if (the_authctxt == NULL) {
 185                 error("BSM audit: session setup internal error (NULL ctxt)");
 186                 return;
 187         }
 188
 189         if (the_authctxt->valid)
 190                 info.ai_auid = the_authctxt->pw->pw_uid;
 191         else
 192                 info.ai_auid = -1;
 193         info.ai_asid = getpid();
 194         mask.am_success = 0;
 195         mask.am_failure = 0;
 196
 197         (void) au_user_mask(the_authctxt->user, &mask);
 198
 199         info.ai_mask.am_success  = mask.am_success;
 200         info.ai_mask.am_failure  = mask.am_failure;
 201
 202         info.ai_termid = ssh_bsm_tid;
 203
 204         rc = SetAuditFunc(&info, sizeof(info));
 205         if (rc < 0)
 206                 error("BSM audit: %s: %s failed: %s", __func__,
 207                     SetAuditFuncText, strerror(errno));
 208 }
 209
 210 static void
 211 bsm_audit_bad_login(const char *what)
 212 {
 213         char textbuf[BSM_TEXTBUFSZ];
 214
 215         if (the_authctxt->valid) {
 216                 (void) snprintf(textbuf, sizeof (textbuf),
 217                         gettext("invalid %s for user %s"),
 218                             what, the_authctxt->user);
 219                 bsm_audit_record(4, textbuf, AUE_openssh);
 220         } else {
 221                 (void) snprintf(textbuf, sizeof (textbuf),
 222                         gettext("invalid user name \"%s\""),
 223                             the_authctxt->user);
 224                 bsm_audit_record(3, textbuf, AUE_openssh);
 225         }
 226 }
 227
 228 /* Below is the sshd audit API code */
 229
 230 void
 231 audit_connection_from(const char *host, int port)
 232 {
 233         AuditInfoTermID *tid = &ssh_bsm_tid;
 234         char buf[1024];
 235
 236         if (cannot_audit(0))
 237                 return;
 238         debug3("BSM audit: connection from %.100s port %d", host, port);
 239
 240         /* populate our terminal id structure */
 241 #if defined(HAVE_GETAUDIT_ADDR)
 242         tid->at_port = (dev_t)port;
 243         aug_get_machine((char *)host, &(tid->at_addr[0]), &(tid->at_type));
 244         snprintf(buf, sizeof(buf), "%08x %08x %08x %08x", tid->at_addr[0],
 245             tid->at_addr[1], tid->at_addr[2], tid->at_addr[3]);
 246         debug3("BSM audit: iptype %d machine ID %s", (int)tid->at_type, buf);
 247 #else
 248         /* this is used on IPv4-only machines */
 249         tid->port = (dev_t)port;
 250         tid->machine = inet_addr(host);
 251         snprintf(buf, sizeof(buf), "%08x", tid->machine);
 252         debug3("BSM audit: machine ID %s", buf);
 253 #endif
 254 }
 255
 256 void
 257 audit_run_command(const char *command)
 258 {
 259         /* not implemented */
 260 }
 261
 262 void
 263 audit_session_open(const char *ttyn)
 264 {
 265         /* not implemented */
 266 }
 267
 268 void
 269 audit_session_close(const char *ttyn)
 270 {
 271         /* not implemented */
 272 }
 273
 274 void
 275 audit_event(ssh_audit_event_t event)
 276 {
 277         char    textbuf[BSM_TEXTBUFSZ];
 278         static int logged_in = 0;
 279         const char *user = the_authctxt ? the_authctxt->user : "(unknown user)";
 280
 281         if (cannot_audit(0))
 282                 return;
 283
 284         switch(event) {
 285         case SSH_AUTH_SUCCESS:
 286                 logged_in = 1;
 287                 bsm_audit_session_setup();
 288                 snprintf(textbuf, sizeof(textbuf),
 289                     gettext("successful login %s"), user);
 290                 bsm_audit_record(0, textbuf, AUE_openssh);
 291                 break;
 292
 293         case SSH_CONNECTION_CLOSE:
 294                 /*
 295                  * We can also get a close event if the user attempted auth
 296                  * but never succeeded.
 297                  */
 298                 if (logged_in) {
 299                         snprintf(textbuf, sizeof(textbuf),
 300                             gettext("sshd logout %s"), the_authctxt->user);
 301                         bsm_audit_record(0, textbuf, AUE_logout);
 302                 } else {
 303                         debug("%s: connection closed without authentication",
 304                             __func__);
 305                 }
 306                 break;
 307
 308         case SSH_NOLOGIN:
 309                 bsm_audit_record(1,
 310                     gettext("logins disabled by /etc/nologin"), AUE_openssh);
 311                 break;
 312
 313         case SSH_LOGIN_EXCEED_MAXTRIES:
 314                 snprintf(textbuf, sizeof(textbuf),
 315                     gettext("too many tries for user %s"), the_authctxt->user);
 316                 bsm_audit_record(1, textbuf, AUE_openssh);
 317                 break;
 318
 319         case SSH_LOGIN_ROOT_DENIED:
 320                 bsm_audit_record(2, gettext("not_console"), AUE_openssh);
 321                 break;
 322
 323         case SSH_AUTH_FAIL_PASSWD:
 324                 bsm_audit_bad_login("password");
 325                 break;
 326
 327         case SSH_AUTH_FAIL_KBDINT:
 328                 bsm_audit_bad_login("interactive password entry");
 329                 break;
 330
 331         default:
 332                 debug("%s: unhandled event %d", __func__, event);
 333         }
 334 }
 335 #endif /* BSM */