login.tproj/login_audit.c

   1 /*
   2  * Copyright (c) 2005-2016 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_BSD_LICENSE_HEADER_START@
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1.  Redistributions of source code must retain the above copyright
  11  *     notice, this list of conditions and the following disclaimer.
  12  * 2.  Redistributions in binary form must reproduce the above copyright
  13  *     notice, this list of conditions and the following disclaimer in the
  14  *     documentation and/or other materials provided with the distribution.
  15  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
  16  *     its contributors may be used to endorse or promote products derived
  17  *     from this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
  20  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  21  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  22  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
  23  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  24  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  25  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  26  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  *
  30  * @APPLE_BSD_LICENSE_HEADER_END@
  31  */
  32
  33 #ifdef USE_BSM_AUDIT
  34
  35 #include <sys/cdefs.h>
  36 __FBSDID("$FreeBSD: src/usr.bin/login/login_audit.c,v 1.2 2007/05/07 11:01:36 dwmalone Exp $");
  37
  38 #include <sys/types.h>
  39
  40 #include <bsm/libbsm.h>
  41 #include <bsm/audit_uevents.h>
  42 #include <bsm/audit_session.h>
  43
  44 #include <err.h>
  45 #include <errno.h>
  46 #include <pwd.h>
  47 #include <stdio.h>
  48 #include <stdlib.h>
  49 #include <strings.h>
  50 #include <unistd.h>
  51
  52 #include "login.h"
  53
  54 /*
  55  * Audit data
  56  */
  57 au_tid_addr_t tid;
  58
  59 /*
  60  * The following tokens are included in the audit record for a successful
  61  * login: header, subject, return.
  62  */
  63 void
  64 au_login_success(int fflag)
  65 {
  66         token_t *tok;
  67         int aufd;
  68         auditinfo_addr_t auinfo;
  69         uid_t uid = pwd->pw_uid;
  70         gid_t gid = pwd->pw_gid;
  71         pid_t pid = getpid();
  72         long au_cond;
  73
  74         /* Determine whether auditing is enabled. */
  75         if (auditon(A_GETCOND, &au_cond, sizeof(long)) < 0) {
  76                 if (errno == ENOSYS)
  77                         return;
  78                 errx(1, "login: Could not determine audit condition");
  79         }
  80
  81         /* Initialize with the current audit info. */
  82         if (getaudit_addr(&auinfo, sizeof(auinfo)) < 0) {
  83                 err(1, "getaudit_addr");
  84         }
  85         auinfo.ai_auid = pwd->pw_uid;
  86         memcpy(&auinfo.ai_termid, &tid, sizeof(auinfo.ai_termid));
  87
  88         /* Do the SessionCreate() equivalent. */
  89         if (!fflag) {
  90                 auinfo.ai_asid = AU_ASSIGN_ASID;
  91                 auinfo.ai_flags |= AU_SESSION_FLAG_HAS_TTY;
  92                 auinfo.ai_flags |= AU_SESSION_FLAG_HAS_AUTHENTICATED;
  93         }
  94
  95         if (au_cond != AUC_NOAUDIT) {
  96                 /* Compute and set the user's preselection mask. */
  97                 if (au_user_mask(pwd->pw_name, &auinfo.ai_mask) < 0) {
  98                         errx(1, "login: Could not set audit mask\n");
  99                 }
 100         }
 101
 102         if (setaudit_addr(&auinfo, sizeof(auinfo)) < 0)
 103                 err(1, "login: setaudit_addr failed");
 104
 105         char *session = NULL;
 106         asprintf(&session, "%x", auinfo.ai_asid);
 107         if (NULL == session) {
 108                 errx(1, "asprintf failed");
 109         }
 110         setenv("SECURITYSESSIONID", session, 1);
 111         free(session);
 112
 113         /* If we are not auditing, don't cut an audit record; just return. */
 114         if (au_cond == AUC_NOAUDIT)
 115                 return;
 116
 117         if ((aufd = au_open()) == -1)
 118                 errx(1,"login: Audit Error: au_open() failed");
 119
 120         if ((tok = au_to_subject32_ex(uid, geteuid(), getegid(), uid, gid, pid,
 121             pid, &tid)) == NULL)
 122                 errx(1, "login: Audit Error: au_to_subject32() failed");
 123         au_write(aufd, tok);
 124
 125         if ((tok = au_to_return32(0, 0)) == NULL)
 126                 errx(1, "login: Audit Error: au_to_return32() failed");
 127         au_write(aufd, tok);
 128
 129         if (au_close(aufd, 1, AUE_login) == -1)
 130                 errx(1, "login: Audit Record was not committed.");
 131 }
 132
 133 /*
 134  * The following tokens are included in the audit record for failed
 135  * login attempts: header, subject, text, return.
 136  */
 137 void
 138 au_login_fail(const char *errmsg, int na)
 139 {
 140         token_t *tok;
 141         int aufd;
 142         long au_cond;
 143         uid_t uid;
 144         gid_t gid;
 145         pid_t pid = getpid();
 146
 147         /* If we are not auditing, don't cut an audit record; just return. */
 148         if (auditon(A_GETCOND, &au_cond, sizeof(long)) < 0) {
 149                 if (errno == ENOSYS)
 150                         return;
 151                 errx(1, "login: Could not determine audit condition");
 152         }
 153         if (au_cond == AUC_NOAUDIT)
 154                 return;
 155
 156         if ((aufd = au_open()) == -1)
 157                 errx(1, "login: Audit Error: au_open() failed");
 158
 159         if (na) {
 160                 /*
 161                  * Non attributable event.  Assuming that login is not called
 162                  * within a user's session => auid,asid == -1.
 163                  */
 164                 if ((tok = au_to_subject32_ex(-1, geteuid(), getegid(), -1, -1,
 165                     pid, -1, &tid)) == NULL)
 166                         errx(1, "login: Audit Error: au_to_subject32() failed");
 167         } else {
 168                 /* We know the subject -- so use its value instead. */
 169                 uid = pwd->pw_uid;
 170                 gid = pwd->pw_gid;
 171                 if ((tok = au_to_subject32_ex(uid, geteuid(), getegid(), uid,
 172                     gid, pid, pid, &tid)) == NULL)
 173                         errx(1, "login: Audit Error: au_to_subject32() failed");
 174         }
 175         au_write(aufd, tok);
 176
 177         /* Include the error message. */
 178         if ((tok = au_to_text(errmsg)) == NULL)
 179                 errx(1, "login: Audit Error: au_to_text() failed");
 180         au_write(aufd, tok);
 181
 182         if ((tok = au_to_return32(1, errno)) == NULL)
 183                 errx(1, "login: Audit Error: au_to_return32() failed");
 184         au_write(aufd, tok);
 185
 186         if (au_close(aufd, 1, AUE_login) == -1)
 187                 errx(1, "login: Audit Error: au_close() was not committed");
 188 }
 189
 190 /*
 191  * The following tokens are included in the audit record for a logout:
 192  * header, subject, return.
 193  */
 194 void
 195 audit_logout(void)
 196 {
 197         token_t *tok;
 198         int aufd;
 199         uid_t uid = pwd->pw_uid;
 200         gid_t gid = pwd->pw_gid;
 201         pid_t pid = getpid();
 202         long au_cond;
 203
 204         /* If we are not auditing, don't cut an audit record; just return. */
 205         if (auditon(A_GETCOND, &au_cond, sizeof(long)) < 0) {
 206                 if (errno == ENOSYS)
 207                         return;
 208                 errx(1, "login: Could not determine audit condition");
 209         }
 210         if (au_cond == AUC_NOAUDIT)
 211                 return;
 212
 213         if ((aufd = au_open()) == -1)
 214                 errx(1, "login: Audit Error: au_open() failed");
 215
 216         /* The subject that is created (euid, egid of the current process). */
 217         if ((tok = au_to_subject32_ex(uid, geteuid(), getegid(), uid, gid, pid,
 218             pid, &tid)) == NULL)
 219                 errx(1, "login: Audit Error: au_to_subject32() failed");
 220         au_write(aufd, tok);
 221
 222         if ((tok = au_to_return32(0, 0)) == NULL)
 223                 errx(1, "login: Audit Error: au_to_return32() failed");
 224         au_write(aufd, tok);
 225
 226         if (au_close(aufd, 1, AUE_logout) == -1)
 227                 errx(1, "login: Audit Record was not committed.");
 228 }
 229
 230 #endif /* USE_BSM_AUDIT */