1 files changed, 58 insertions, 22 deletions

diff --git a/ssh-agent.c b/ssh-agent.c
index aeda656ac..34b19b754 100644
--- a/ssh-agent.c
+++ b/ssh-agent.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-agent.c,v 1.199 2015/03/04 21:12:59 djm Exp $ */
+/* $OpenBSD: ssh-agent.c,v 1.203 2015/05/15 05:44:21 dtucker Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -68,6 +68,9 @@
 #include <time.h>
 #include <string.h>
 #include <unistd.h>
+#ifdef HAVE_UTIL_H
+# include <util.h>
+#endif
 
 #include "key.h"        /* XXX for typedef */
 #include "buffer.h"     /* XXX for typedef */
@@ -140,8 +143,12 @@ char socket_name[PATH_MAX];
 char socket_dir[PATH_MAX];
 
 /* locking */
+#define LOCK_SIZE       32
+#define LOCK_SALT_SIZE  16
+#define LOCK_ROUNDS     1
 int locked = 0;
-char *lock_passwd = NULL;
+char lock_passwd[LOCK_SIZE];
+char lock_salt[LOCK_SALT_SIZE];
 
 extern char *__progname;
 
@@ -660,23 +667,45 @@ send:
 static void
 process_lock_agent(SocketEntry *e, int lock)
 {
-        int r, success = 0;
-        char *passwd;
+        int r, success = 0, delay;
+        char *passwd, passwdhash[LOCK_SIZE];
+        static u_int fail_count = 0;
+        size_t pwlen;
 
-        if ((r = sshbuf_get_cstring(e->request, &passwd, NULL)) != 0)
+        if ((r = sshbuf_get_cstring(e->request, &passwd, &pwlen)) != 0)
                 fatal("%s: buffer error: %s", __func__, ssh_err(r));
-        if (locked && !lock && strcmp(passwd, lock_passwd) == 0) {
-                locked = 0;
-                explicit_bzero(lock_passwd, strlen(lock_passwd));
-                free(lock_passwd);
-                lock_passwd = NULL;
-                success = 1;
+        if (pwlen == 0) {
+                debug("empty password not supported");
+        } else if (locked && !lock) {
+                if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
+                    passwdhash, sizeof(passwdhash), LOCK_ROUNDS) < 0)
+                        fatal("bcrypt_pbkdf");
+                if (timingsafe_bcmp(passwdhash, lock_passwd, LOCK_SIZE) == 0) {
+                        debug("agent unlocked");
+                        locked = 0;
+                        fail_count = 0;
+                        explicit_bzero(lock_passwd, sizeof(lock_passwd));
+                        success = 1;
+                } else {
+                        /* delay in 0.1s increments up to 10s */
+                        if (fail_count < 100)
+                                fail_count++;
+                        delay = 100000 * fail_count;
+                        debug("unlock failed, delaying %0.1lf seconds",
+                            (double)delay/1000000);
+                        usleep(delay);
+                }
+                explicit_bzero(passwdhash, sizeof(passwdhash));
         } else if (!locked && lock) {
+                debug("agent locked");
                 locked = 1;
-                lock_passwd = xstrdup(passwd);
+                arc4random_buf(lock_salt, sizeof(lock_salt));
+                if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
+                    lock_passwd, sizeof(lock_passwd), LOCK_ROUNDS) < 0)
+                        fatal("bcrypt_pbkdf");
                 success = 1;
         }
-        explicit_bzero(passwd, strlen(passwd));
+        explicit_bzero(passwd, pwlen);
         free(passwd);
         send_status(e, success);
 }
@@ -929,7 +958,7 @@ new_socket(sock_type type, int fd)
                 }
         old_alloc = sockets_alloc;
         new_alloc = sockets_alloc + 10;
-        sockets = xrealloc(sockets, new_alloc, sizeof(sockets[0]));
+        sockets = xreallocarray(sockets, new_alloc, sizeof(sockets[0]));
         for (i = old_alloc; i < new_alloc; i++)
                 sockets[i].type = AUTH_UNUSED;
         sockets_alloc = new_alloc;
@@ -1137,7 +1166,7 @@ static void
 usage(void)
 {
         fprintf(stderr,
-            "usage: ssh-agent [-c | -s] [-d] [-a bind_address] [-E fingerprint_hash]\n"
+            "usage: ssh-agent [-c | -s] [-Dd] [-a bind_address] [-E fingerprint_hash]\n"
             "                 [-t life] [command [arg ...]]\n"
             "       ssh-agent [-c | -s] -k\n");
         exit(1);
@@ -1146,7 +1175,7 @@ usage(void)
 int
 main(int ac, char **av)
 {
-        int c_flag = 0, d_flag = 0, k_flag = 0, s_flag = 0;
+        int c_flag = 0, d_flag = 0, D_flag = 0, k_flag = 0, s_flag = 0;
         int sock, fd, ch, result, saved_errno;
         u_int nalloc;
         char *shell, *format, *pidstr, *agentsocket = NULL;
@@ -1181,7 +1210,7 @@ main(int ac, char **av)
         __progname = ssh_get_progname(av[0]);
         seed_rng();
 
-        while ((ch = getopt(ac, av, "cdksE:a:t:")) != -1) {
+        while ((ch = getopt(ac, av, "cDdksE:a:t:")) != -1) {
                 switch (ch) {
                 case 'E':
                         fingerprint_hash = ssh_digest_alg_by_name(optarg);
@@ -1202,10 +1231,15 @@ main(int ac, char **av)
                         s_flag++;
                         break;
                 case 'd':
-                        if (d_flag)
+                        if (d_flag || D_flag)
                                 usage();
                         d_flag++;
                         break;
+                case 'D':
+                        if (d_flag || D_flag)
+                                usage();
+                        D_flag++;
+                        break;
                 case 'a':
                         agentsocket = optarg;
                         break;
@@ -1222,7 +1256,7 @@ main(int ac, char **av)
         ac -= optind;
         av += optind;
 
-        if (ac > 0 && (c_flag || k_flag || s_flag || d_flag))
+        if (ac > 0 && (c_flag || k_flag || s_flag || d_flag || D_flag))
                 usage();
 
         if (ac == 0 && !c_flag && !s_flag) {
@@ -1291,8 +1325,10 @@ main(int ac, char **av)
          * Fork, and have the parent execute the command, if any, or present
          * the socket data.  The child continues as the authentication agent.
          */
-        if (d_flag) {
-                log_init(__progname, SYSLOG_LEVEL_DEBUG1, SYSLOG_FACILITY_AUTH, 1);
+        if (D_flag || d_flag) {
+                log_init(__progname,
+                    d_flag ? SYSLOG_LEVEL_DEBUG3 : SYSLOG_LEVEL_INFO,
+                    SYSLOG_FACILITY_AUTH, 1);
                 format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
                 printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
                     SSH_AUTHSOCKET_ENV_NAME);
@@ -1364,7 +1400,7 @@ skip:
                 parent_alive_interval = 10;
         idtab_init();
         signal(SIGPIPE, SIG_IGN);
-        signal(SIGINT, d_flag ? cleanup_handler : SIG_IGN);
+        signal(SIGINT, (d_flag | D_flag) ? cleanup_handler : SIG_IGN);
         signal(SIGHUP, cleanup_handler);
         signal(SIGTERM, cleanup_handler);
         nalloc = 0;