diff options
Diffstat (limited to 'audit-bsm.c')
-rw-r--r-- | audit-bsm.c | 455 |
1 files changed, 455 insertions, 0 deletions
diff --git a/audit-bsm.c b/audit-bsm.c new file mode 100644 index 0000000..ccfcf6f --- /dev/null +++ b/audit-bsm.c @@ -0,0 +1,455 @@ +/* + * TODO + * + * - deal with overlap between this and sys_auth_allowed_user + * sys_auth_record_login and record_failed_login. + */ + +/* + * Copyright 1988-2002 Sun Microsystems, Inc. All rights reserved. + * Use is subject to license terms. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + */ +/* #pragma ident "@(#)bsmaudit.c 1.1 01/09/17 SMI" */ + +#include "includes.h" +#if defined(USE_BSM_AUDIT) + +#include <sys/types.h> + +#include <errno.h> +#include <netdb.h> +#include <stdarg.h> +#include <string.h> +#include <unistd.h> + +#ifdef BROKEN_BSM_API +#include <libscf.h> +#endif + +#include "ssh.h" +#include "log.h" +#include "hostfile.h" +#include "auth.h" +#include "xmalloc.h" + +#ifndef AUE_openssh +# define AUE_openssh 32800 +#endif +#include <bsm/audit.h> +#include <bsm/libbsm.h> +#include <bsm/audit_uevents.h> +#include <bsm/audit_record.h> +#include <locale.h> + +#if defined(HAVE_GETAUDIT_ADDR) +#define AuditInfoStruct auditinfo_addr +#define AuditInfoTermID au_tid_addr_t +#define SetAuditFunc(a,b) setaudit_addr((a),(b)) +#define SetAuditFuncText "setaudit_addr" +#define AUToSubjectFunc au_to_subject_ex +#define AUToReturnFunc(a,b) au_to_return32((a), (int32_t)(b)) +#else +#define AuditInfoStruct auditinfo +#define AuditInfoTermID au_tid_t +#define SetAuditFunc(a,b) setaudit(a) +#define SetAuditFuncText "setaudit" +#define AUToSubjectFunc au_to_subject +#define AUToReturnFunc(a,b) au_to_return((a), (u_int)(b)) +#endif + +#ifndef cannot_audit +extern int cannot_audit(int); +#endif +extern void aug_init(void); +extern void aug_save_auid(au_id_t); +extern void aug_save_uid(uid_t); +extern void aug_save_euid(uid_t); +extern void aug_save_gid(gid_t); +extern void aug_save_egid(gid_t); +extern void aug_save_pid(pid_t); +extern void aug_save_asid(au_asid_t); +extern void aug_save_tid(dev_t, unsigned int); +extern void aug_save_tid_ex(dev_t, u_int32_t *, u_int32_t); +extern int aug_save_me(void); +extern int aug_save_namask(void); +extern void aug_save_event(au_event_t); +extern void aug_save_sorf(int); +extern void aug_save_text(char *); +extern void aug_save_text1(char *); +extern void aug_save_text2(char *); +extern void aug_save_na(int); +extern void aug_save_user(char *); +extern void aug_save_path(char *); +extern int aug_save_policy(void); +extern void aug_save_afunc(int (*)(int)); +extern int aug_audit(void); +extern int aug_na_selected(void); +extern int aug_selected(void); +extern int aug_daemon_session(void); + +#ifndef HAVE_GETTEXT +# define gettext(a) (a) +#endif + +extern Authctxt *the_authctxt; +static AuditInfoTermID ssh_bsm_tid; + +#ifdef BROKEN_BSM_API +/* For some reason this constant is no longer defined + in Solaris 11. */ +#define BSM_TEXTBUFSZ 256 +#endif + +/* Below is the low-level BSM interface code */ + +/* + * aug_get_machine is only required on IPv6 capable machines, we use a + * different mechanism in audit_connection_from() for IPv4-only machines. + * getaudit_addr() is only present on IPv6 capable machines. + */ +#if defined(HAVE_AUG_GET_MACHINE) || !defined(HAVE_GETAUDIT_ADDR) +extern int aug_get_machine(char *, u_int32_t *, u_int32_t *); +#else +static int +aug_get_machine(char *host, u_int32_t *addr, u_int32_t *type) +{ + struct addrinfo *ai; + struct sockaddr_in *in4; + struct sockaddr_in6 *in6; + int ret = 0, r; + + if ((r = getaddrinfo(host, NULL, NULL, &ai)) != 0) { + error("BSM audit: getaddrinfo failed for %.100s: %.100s", host, + r == EAI_SYSTEM ? strerror(errno) : gai_strerror(r)); + return -1; + } + + switch (ai->ai_family) { + case AF_INET: + in4 = (struct sockaddr_in *)ai->ai_addr; + *type = AU_IPv4; + memcpy(addr, &in4->sin_addr, sizeof(struct in_addr)); + break; +#ifdef AU_IPv6 + case AF_INET6: + in6 = (struct sockaddr_in6 *)ai->ai_addr; + *type = AU_IPv6; + memcpy(addr, &in6->sin6_addr, sizeof(struct in6_addr)); + break; +#endif + default: + error("BSM audit: unknown address family for %.100s: %d", + host, ai->ai_family); + ret = -1; + } + freeaddrinfo(ai); + return ret; +} +#endif + +#ifdef BROKEN_BSM_API +/* + In Solaris 11 the audit daemon has been moved to SMF. In the process + they simply dropped getacna() from the API, since it read from a now + non-existent config file. This function re-implements getacna() to + read from the SMF repository instead. + */ +int +getacna(char *auditstring, int len) +{ + scf_handle_t *handle = NULL; + scf_property_t *property = NULL; + scf_value_t *value = NULL; + int ret = 0; + + /* + * The man page for getacna on Solaris 10 states we should return -2 + * in case of error and set errno to indicate the error. We don't + * bother with errno here, though, since the only use of this function + * below doesn't check for errors anyway. + */ + handle = scf_handle_create(SCF_VERSION); + if (handle == NULL) + return -2; + + ret = scf_handle_bind(handle); + if (ret == -1) + return -2; + + property = scf_property_create(handle); + if (property == NULL) + return -2; + + ret = scf_handle_decode_fmri(handle, + "svc:/system/auditd:default/:properties/preselection/naflags", + NULL, NULL, NULL, NULL, property, 0); + if (ret == -1) + return -2; + + value = scf_value_create(handle); + if (value == NULL) + return -2; + + ret = scf_property_get_value(property, value); + if (ret == -1) + return -2; + + ret = scf_value_get_astring(value, auditstring, len); + if (ret == -1) + return -2; + + scf_value_destroy(value); + scf_property_destroy(property); + scf_handle_destroy(handle); + + return 0; +} +#endif + +/* + * Check if the specified event is selected (enabled) for auditing. + * Returns 1 if the event is selected, 0 if not and -1 on failure. + */ +static int +selected(char *username, uid_t uid, au_event_t event, int sf) +{ + int rc, sorf; + char naflags[512]; + struct au_mask mask; + + mask.am_success = mask.am_failure = 0; + if (uid < 0) { + /* get flags for non-attributable (to a real user) events */ + rc = getacna(naflags, sizeof(naflags)); + if (rc == 0) + (void) getauditflagsbin(naflags, &mask); + } else + rc = au_user_mask(username, &mask); + + sorf = (sf == 0) ? AU_PRS_SUCCESS : AU_PRS_FAILURE; + return(au_preselect(event, &mask, sorf, AU_PRS_REREAD)); +} + +static void +bsm_audit_record(int typ, char *string, au_event_t event_no) +{ + int ad, rc, sel; + uid_t uid = -1; + gid_t gid = -1; + pid_t pid = getpid(); + AuditInfoTermID tid = ssh_bsm_tid; + + if (the_authctxt != NULL && the_authctxt->valid) { + uid = the_authctxt->pw->pw_uid; + gid = the_authctxt->pw->pw_gid; + } + + rc = (typ == 0) ? 0 : -1; + sel = selected(the_authctxt->user, uid, event_no, rc); + debug3("BSM audit: typ %d rc %d \"%s\"", typ, rc, string); + if (!sel) + return; /* audit event does not match mask, do not write */ + + debug3("BSM audit: writing audit new record"); + ad = au_open(); + + (void) au_write(ad, AUToSubjectFunc(uid, uid, gid, uid, gid, + pid, pid, &tid)); + (void) au_write(ad, au_to_text(string)); + (void) au_write(ad, AUToReturnFunc(typ, rc)); + +#ifdef BROKEN_BSM_API + /* + * The last argument is the event modifier flags. For some seemingly + * undocumented reason it was added in Solaris 11. + */ + rc = au_close(ad, AU_TO_WRITE, event_no, 0); +#else + rc = au_close(ad, AU_TO_WRITE, event_no); +#endif + + if (rc < 0) + error("BSM audit: %s failed to write \"%s\" record: %s", + __func__, string, strerror(errno)); +} + +static void +bsm_audit_session_setup(void) +{ + int rc; + struct AuditInfoStruct info; + au_mask_t mask; + + if (the_authctxt == NULL) { + error("BSM audit: session setup internal error (NULL ctxt)"); + return; + } + + if (the_authctxt->valid) + info.ai_auid = the_authctxt->pw->pw_uid; + else + info.ai_auid = -1; + info.ai_asid = getpid(); + mask.am_success = 0; + mask.am_failure = 0; + + (void) au_user_mask(the_authctxt->user, &mask); + + info.ai_mask.am_success = mask.am_success; + info.ai_mask.am_failure = mask.am_failure; + + info.ai_termid = ssh_bsm_tid; + + rc = SetAuditFunc(&info, sizeof(info)); + if (rc < 0) + error("BSM audit: %s: %s failed: %s", __func__, + SetAuditFuncText, strerror(errno)); +} + +static void +bsm_audit_bad_login(const char *what) +{ + char textbuf[BSM_TEXTBUFSZ]; + + if (the_authctxt->valid) { + (void) snprintf(textbuf, sizeof (textbuf), + gettext("invalid %s for user %s"), + what, the_authctxt->user); + bsm_audit_record(4, textbuf, AUE_openssh); + } else { + (void) snprintf(textbuf, sizeof (textbuf), + gettext("invalid user name \"%s\""), + the_authctxt->user); + bsm_audit_record(3, textbuf, AUE_openssh); + } +} + +/* Below is the sshd audit API code */ + +void +audit_connection_from(const char *host, int port) +{ + AuditInfoTermID *tid = &ssh_bsm_tid; + char buf[1024]; + + if (cannot_audit(0)) + return; + debug3("BSM audit: connection from %.100s port %d", host, port); + + /* populate our terminal id structure */ +#if defined(HAVE_GETAUDIT_ADDR) + tid->at_port = (dev_t)port; + aug_get_machine((char *)host, &(tid->at_addr[0]), &(tid->at_type)); + snprintf(buf, sizeof(buf), "%08x %08x %08x %08x", tid->at_addr[0], + tid->at_addr[1], tid->at_addr[2], tid->at_addr[3]); + debug3("BSM audit: iptype %d machine ID %s", (int)tid->at_type, buf); +#else + /* this is used on IPv4-only machines */ + tid->port = (dev_t)port; + tid->machine = inet_addr(host); + snprintf(buf, sizeof(buf), "%08x", tid->machine); + debug3("BSM audit: machine ID %s", buf); +#endif +} + +void +audit_run_command(const char *command) +{ + /* not implemented */ +} + +void +audit_session_open(struct logininfo *li) +{ + /* not implemented */ +} + +void +audit_session_close(struct logininfo *li) +{ + /* not implemented */ +} + +void +audit_event(struct ssh *ssh, ssh_audit_event_t event) +{ + char textbuf[BSM_TEXTBUFSZ]; + static int logged_in = 0; + const char *user = the_authctxt ? the_authctxt->user : "(unknown user)"; + + if (cannot_audit(0)) + return; + + switch(event) { + case SSH_AUTH_SUCCESS: + logged_in = 1; + bsm_audit_session_setup(); + snprintf(textbuf, sizeof(textbuf), + gettext("successful login %s"), user); + bsm_audit_record(0, textbuf, AUE_openssh); + break; + + case SSH_CONNECTION_CLOSE: + /* + * We can also get a close event if the user attempted auth + * but never succeeded. + */ + if (logged_in) { + snprintf(textbuf, sizeof(textbuf), + gettext("sshd logout %s"), the_authctxt->user); + bsm_audit_record(0, textbuf, AUE_logout); + } else { + debug("%s: connection closed without authentication", + __func__); + } + break; + + case SSH_NOLOGIN: + bsm_audit_record(1, + gettext("logins disabled by /etc/nologin"), AUE_openssh); + break; + + case SSH_LOGIN_EXCEED_MAXTRIES: + snprintf(textbuf, sizeof(textbuf), + gettext("too many tries for user %s"), the_authctxt->user); + bsm_audit_record(1, textbuf, AUE_openssh); + break; + + case SSH_LOGIN_ROOT_DENIED: + bsm_audit_record(2, gettext("not_console"), AUE_openssh); + break; + + case SSH_AUTH_FAIL_PASSWD: + bsm_audit_bad_login("password"); + break; + + case SSH_AUTH_FAIL_KBDINT: + bsm_audit_bad_login("interactive password entry"); + break; + + default: + debug("%s: unhandled event %d", __func__, event); + } +} +#endif /* BSM */ |