Relevant BUGIDs:

Purpose of commit: new feature

Commit summary:
---------------
2006-01-12  Steve Grubb  <sgrubb@redhat.com>

        * configure.in: Add check for audit library.
        * libpam/Makefile.am (libpam_la_LDFLAGS): Add LIBAUDIT.
        (libpam_la_SOURCES): Add pam_audit.c.
        * libpam/pam_account.c (pam_acct_mgmt): Add _pam_auditlog() call.
        * libpam/pam_auth.c (pam_authenticate), (pam_setcred): Likewise.
        * libpam/pam_password.c (pam_chauthtok):  Likewise.
        * libpam/pam_session.c (pam_open_session),
        (pam_close_session): Likewise.
        * libpam/pam_private.h: Add audit_state member to pam_handle,
        declare _pam_auditlog and _pam_audit_end.
        * libpam/pam_start.c (pam_start): Initialize audit_state.
        * libpam/pam_audit.c: New file with _pam_auditlog and _pam_audit_end
        implementation.
        * libpam/pam_end.c (pam_end): Add _pam_audit_end() call.
        * NEWS: Note about added auditing.

1 files changed, 128 insertions, 0 deletions

diff --git a/libpam/pam_audit.c b/libpam/pam_audit.c
new file mode 100644
index 00000000..7c067d9b
--- /dev/null
+++ b/libpam/pam_audit.c
@@ -0,0 +1,128 @@
+/* pam_audit.c -- Instrumentation code for Linux Auditing System  */
+
+/* (C) 2005-2006 Red Hat, Inc. -- Licensing details are in the COPYING
+   file accompanying the Linux-PAM source distribution.
+
+   Authors:
+   Steve Grubb <sgrubb@redhat.com> */
+
+#include "pam_private.h"
+#include <stdio.h>
+#include <syslog.h>
+
+#if HAVE_LIBAUDIT
+#include <libaudit.h>
+#include <pwd.h>
+#include <netdb.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <errno.h>
+
+#define PAMAUDIT_LOGGED 1
+
+static int
+_pam_audit_writelog(pam_handle_t *pamh, int audit_fd, int type, 
+	const char *message, int retval)
+{
+  int rc;
+  char buf[256];
+
+  snprintf(buf, sizeof(buf), "PAM: %s acct=%s ", message, 
+	(retval != PAM_USER_UNKNOWN && pamh->user) ? pamh->user : "?");
+
+  rc = audit_log_user_message( audit_fd, type, buf,
+        pamh->rhost, NULL, pamh->tty, retval == PAM_SUCCESS );
+
+  pamh->audit_state |= PAMAUDIT_LOGGED;
+  return rc;
+}
+
+int
+_pam_auditlog(pam_handle_t *pamh, int action, int retval, int flags)
+{
+  const char *message;
+  int type;
+  int audit_fd;
+
+  audit_fd = audit_open();
+  if (audit_fd < 0) {
+    /* You get these error codes only when the kernel doesn't have
+     * audit compiled in. */
+    if (errno == EINVAL || errno == EPROTONOSUPPORT ||
+        errno == EAFNOSUPPORT)
+        return retval;
+
+    /* this should only fail in case of extreme resource shortage,
+     * need to prevent login in that case for CAPP compliance.
+     */
+    pam_syslog(pamh, LOG_CRIT, "audit_open() failed: %s",
+		    strerror(errno));
+    return PAM_SYSTEM_ERR;
+  }
+                          
+  switch (action) {
+  case PAM_AUTHENTICATE:
+    message = "authentication";
+    type = AUDIT_USER_AUTH;
+    break;
+  case PAM_OPEN_SESSION:
+    message = "session open";
+    type = AUDIT_USER_START;
+    break;
+  case PAM_CLOSE_SESSION:
+    message = "session close";
+    type = AUDIT_USER_END;
+    break;
+  case PAM_ACCOUNT:
+    message = "accounting";
+    type = AUDIT_USER_ACCT;
+    break;
+  case PAM_CHAUTHTOK:
+    message = "chauthtok";
+    type = AUDIT_USER_CHAUTHTOK;
+    break;
+  case PAM_SETCRED:
+    message = "setcred";
+    if (flags & PAM_ESTABLISH_CRED)
+	type = AUDIT_CRED_ACQ;
+    else if ((flags & PAM_REINITIALIZE_CRED) || (flags & PAM_REFRESH_CRED))
+	type = AUDIT_CRED_REFR;
+    else if (flags & PAM_DELETE_CRED)
+	type = AUDIT_CRED_DISP;
+    else
+        type = AUDIT_USER_ERR;
+    break;
+  case _PAM_ACTION_DONE:
+    message = "bad_ident";
+    type = AUDIT_USER_ERR;
+    break;
+  default:
+    message = "UNKNOWN";
+    type = AUDIT_USER_ERR;
+    pam_syslog(pamh, LOG_CRIT, "_pam_auditlog() should never get here");
+    retval = PAM_SYSTEM_ERR;
+  }
+
+  if (_pam_audit_writelog(pamh, audit_fd, type, message, retval) < 0)
+    retval = PAM_SYSTEM_ERR;
+  
+  audit_close(audit_fd);
+  return retval;
+}
+
+int
+_pam_audit_end(pam_handle_t *pamh, int status UNUSED)
+{
+  if (! (pamh->audit_state & PAMAUDIT_LOGGED)) {
+    /* PAM library is being shut down without any of the auditted
+     * stacks having been run. Assume that this is sshd faking
+     * things for an unknown user.
+     */
+    _pam_auditlog(pamh, _PAM_ACTION_DONE, PAM_USER_UNKNOWN, 0);
+  }
+
+  return 0;
+}
+
+#endif /* HAVE_LIBAUDIT */