freebsd-dev/crypto/openssh/audit-bsm.c
Dag-Erling Smørgrav d4af9e693f Upgrade to OpenSSH 5.1p1.
I have worked hard to reduce diffs against the vendor branch.  One
notable change in that respect is that we no longer prefer DSA over
RSA - the reasons for doing so went away years ago.  This may cause
some surprises, as ssh will warn about unknown host keys even for
hosts whose keys haven't changed.

MFC after:	6 weeks
2008-08-01 02:48:36 +00:00

381 lines
10 KiB
C

/* $Id: audit-bsm.c,v 1.6 2008/02/25 10:05:04 dtucker Exp $ */
/*
* 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>
#include "ssh.h"
#include "log.h"
#include "key.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;
/* 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
/*
* 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));
rc = au_close(ad, AU_TO_WRITE, event_no);
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(const char *ttyn)
{
/* not implemented */
}
void
audit_session_close(const char *ttyn)
{
/* not implemented */
}
void
audit_event(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 */