- (dtucker) [auth.c canohost.c canohost.h configure.ac defines.h loginrec.c]
Bug #974: Teach sshd to write failed login records to btmp for failed auth
attempts (currently only for password, kbdint and C/R, only on Linux and
HP-UX), based on code from login.c from util-linux. With ashok_kovai at
hotmail.com, ok djm@
diff --git a/loginrec.c b/loginrec.c
index 25aa29f..e77318b 100644
--- a/loginrec.c
+++ b/loginrec.c
@@ -25,6 +25,27 @@
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
+/*
+ * The btmp logging code is derived from login.c from util-linux and is under
+ * the the following license:
+ *
+ * Copyright (c) 1980, 1987, 1988 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms are permitted
+ * provided that the above copyright notice and this paragraph are
+ * duplicated in all such forms and that any documentation,
+ * advertising materials, and other materials related to such
+ * distribution and use acknowledge that the software was developed
+ * by the University of California, Berkeley. The name of the
+ * University may not be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+ * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+
/**
** loginrec.c: platform-independent login recording and lastlog retrieval
**/
@@ -131,6 +152,8 @@
#include "loginrec.h"
#include "log.h"
#include "atomicio.h"
+#include "packet.h"
+#include "canohost.h"
#ifdef HAVE_UTIL_H
# include <util.h>
@@ -140,7 +163,7 @@
# include <libutil.h>
#endif
-RCSID("$Id: loginrec.c,v 1.62 2004/09/12 05:26:01 djm Exp $");
+RCSID("$Id: loginrec.c,v 1.63 2005/02/02 12:30:25 dtucker Exp $");
/**
** prototypes for helper functions in this file
@@ -1563,3 +1586,82 @@
return (0);
}
#endif /* USE_LASTLOG */
+
+#ifdef USE_BTMP
+ /*
+ * Logs failed login attempts in _PATH_BTMP if that exists.
+ * The most common login failure is to give password instead of username.
+ * So the _PATH_BTMP file checked for the correct permission, so that
+ * only root can read it.
+ */
+
+void
+record_failed_login(const char *username, const char *hostname,
+ const char *ttyn)
+{
+ int fd;
+ struct utmp ut;
+ struct sockaddr_storage from;
+ size_t fromlen = sizeof(from);
+ struct sockaddr_in *a4;
+ struct sockaddr_in6 *a6;
+ time_t t;
+ struct stat fst;
+
+ if (geteuid() != 0)
+ return;
+ if ((fd = open(_PATH_BTMP, O_WRONLY | O_APPEND)) < 0) {
+ debug("Unable to open the btmp file %s: %s", _PATH_BTMP,
+ strerror(errno));
+ return;
+ }
+ if (fstat(fd, &fst) < 0) {
+ logit("%s: fstat of %s failed: %s", __func__, _PATH_BTMP,
+ strerror(errno));
+ goto out;
+ }
+ if((fst.st_mode & (S_IRWXG | S_IRWXO)) || (fst.st_uid != 0)){
+ logit("Excess permission or bad ownership on file %s",
+ _PATH_BTMP);
+ goto out;
+ }
+
+ memset(&ut, 0, sizeof(ut));
+ /* strncpy because we don't necessarily want nul termination */
+ strncpy(ut.ut_user, username, sizeof(ut.ut_user));
+ strlcpy(ut.ut_line, "ssh:notty", sizeof(ut.ut_line));
+
+ time(&t);
+ ut.ut_time = t; /* ut_time is not always a time_t */
+ ut.ut_type = LOGIN_PROCESS;
+ ut.ut_pid = getpid();
+
+ /* strncpy because we don't necessarily want nul termination */
+ strncpy(ut.ut_host, hostname, sizeof(ut.ut_host));
+
+ if (packet_connection_is_on_socket() &&
+ getpeername(packet_get_connection_in(),
+ (struct sockaddr *)&from, &fromlen) == 0) {
+ ipv64_normalise_mapped(&from, &fromlen);
+ if (from.ss_family == AF_INET) {
+ a4 = (struct sockaddr_in *)&from;
+ memcpy(&ut.ut_addr, &(a4->sin_addr),
+ MIN_SIZEOF(ut.ut_addr, a4->sin_addr));
+ }
+#ifdef HAVE_ADDR_V6_IN_UTMP
+ if (from.ss_family == AF_INET6) {
+ a6 = (struct sockaddr_in6 *)&from;
+ memcpy(&ut.ut_addr_v6, &(a6->sin6_addr),
+ MIN_SIZEOF(ut.ut_addr_v6, a6->sin6_addr));
+ }
+#endif
+ }
+
+ if (atomicio(vwrite, fd, &ut, sizeof(ut)) != sizeof(ut))
+ error("Failed to write to %s: %s", _PATH_BTMP,
+ strerror(errno));
+
+out:
+ close(fd);
+}
+#endif /* USE_BTMP */