1 files changed, 121 insertions, 85 deletions

diff --git a/sshconnect.c b/sshconnect.c
index 3c888e36a..01337fe40 100644
--- a/sshconnect.c
+++ b/sshconnect.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshconnect.c,v 1.200 2006/10/10 10:12:45 markus Exp $ */
+/* $OpenBSD: sshconnect.c,v 1.211 2008/07/01 07:24:22 dtucker Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -74,13 +74,6 @@ extern pid_t proxy_command_pid;
 #define INET6_ADDRSTRLEN 46
 #endif
 
-static sig_atomic_t banner_timedout;
-
-static void banner_alarm_catch (int signum)
-{
-        banner_timedout = 1;
-}
-
 static int show_other_keys(const char *, Key *);
 static void warn_changed_key(Key *);
 
@@ -93,7 +86,10 @@ ssh_proxy_connect(const char *host, u_short port, const char *proxy_command)
         char *command_string, *tmp;
         int pin[2], pout[2];
         pid_t pid;
-        char strport[NI_MAXSERV];
+        char *shell, strport[NI_MAXSERV];
+
+        if ((shell = getenv("SHELL")) == NULL)
+                shell = _PATH_BSHELL;
 
         /* Convert the port number into a string. */
         snprintf(strport, sizeof strport, "%hu", port);
@@ -139,7 +135,7 @@ ssh_proxy_connect(const char *host, u_short port, const char *proxy_command)
 
                 /* Stderr is left as it is so that error messages get
                    printed on the user's terminal. */
-                argv[0] = _PATH_BSHELL;
+                argv[0] = shell;
                 argv[1] = "-c";
                 argv[2] = command_string;
                 argv[3] = NULL;
@@ -164,7 +160,9 @@ ssh_proxy_connect(const char *host, u_short port, const char *proxy_command)
         xfree(command_string);
 
         /* Set the connection file descriptors. */
-        packet_set_connection(pout[0], pin[1], options.setuptimeout);
+        packet_set_connection(pout[0], pin[1]);
+        packet_set_timeout(options.server_alive_interval,
+            options.server_alive_count_max);
 
         /* Indicate OK return */
         return 0;
@@ -208,10 +206,10 @@ ssh_create_socket(int privileged, struct addrinfo *ai)
         hints.ai_socktype = ai->ai_socktype;
         hints.ai_protocol = ai->ai_protocol;
         hints.ai_flags = AI_PASSIVE;
-        gaierr = getaddrinfo(options.bind_address, "0", &hints, &res);
+        gaierr = getaddrinfo(options.bind_address, NULL, &hints, &res);
         if (gaierr) {
                 error("getaddrinfo: %s: %s", options.bind_address,
-                    gai_strerror(gaierr));
+                    ssh_gai_strerror(gaierr));
                 close(sock);
                 return -1;
         }
@@ -227,30 +225,36 @@ ssh_create_socket(int privileged, struct addrinfo *ai)
 
 static int
 timeout_connect(int sockfd, const struct sockaddr *serv_addr,
-    socklen_t addrlen, int timeout)
+    socklen_t addrlen, int *timeoutp)
 {
         fd_set *fdset;
-        struct timeval tv;
+        struct timeval tv, t_start;
         socklen_t optlen;
         int optval, rc, result = -1;
 
-        if (timeout <= 0)
-                return (connect(sockfd, serv_addr, addrlen));
+        gettimeofday(&t_start, NULL);
+
+        if (*timeoutp <= 0) {
+                result = connect(sockfd, serv_addr, addrlen);
+                goto done;
+        }
 
         set_nonblock(sockfd);
         rc = connect(sockfd, serv_addr, addrlen);
         if (rc == 0) {
                 unset_nonblock(sockfd);
-                return (0);
+                result = 0;
+                goto done;
+        }
+        if (errno != EINPROGRESS) {
+                result = -1;
+                goto done;
         }
-        if (errno != EINPROGRESS)
-                return (-1);
 
         fdset = (fd_set *)xcalloc(howmany(sockfd + 1, NFDBITS),
             sizeof(fd_mask));
         FD_SET(sockfd, fdset);
-        tv.tv_sec = timeout;
-        tv.tv_usec = 0;
+        ms_to_timeval(&tv, *timeoutp);
 
         for (;;) {
                 rc = select(sockfd + 1, NULL, fdset, NULL, &tv);
@@ -289,6 +293,16 @@ timeout_connect(int sockfd, const struct sockaddr *serv_addr,
         }
 
         xfree(fdset);
+
+ done:
+        if (result == 0 && *timeoutp > 0) {
+                ms_subtract_diff(&t_start, timeoutp);
+                if (*timeoutp <= 0) {
+                        errno = ETIMEDOUT;
+                        result = -1;
+                }
+        }
+
         return (result);
 }
 
@@ -305,8 +319,8 @@ timeout_connect(int sockfd, const struct sockaddr *serv_addr,
  */
 int
 ssh_connect(const char *host, struct sockaddr_storage * hostaddr,
-    u_short port, int family, int connection_attempts,
-    int needpriv, const char *proxy_command)
+    u_short port, int family, int connection_attempts, int *timeout_ms,
+    int want_keepalive, int needpriv, const char *proxy_command)
 {
         int gaierr;
         int on = 1;
@@ -327,8 +341,8 @@ ssh_connect(const char *host, struct sockaddr_storage * hostaddr,
         hints.ai_socktype = SOCK_STREAM;
         snprintf(strport, sizeof strport, "%u", port);
         if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
-                fatal("%s: %.100s: %s", __progname, host,
-                    gai_strerror(gaierr));
+                fatal("%s: Could not resolve hostname %.100s: %s", __progname,
+                    host, ssh_gai_strerror(gaierr));
 
         for (attempt = 0; attempt < connection_attempts; attempt++) {
                 if (attempt > 0) {
@@ -359,7 +373,7 @@ ssh_connect(const char *host, struct sockaddr_storage * hostaddr,
                                 continue;
 
                         if (timeout_connect(sock, ai->ai_addr, ai->ai_addrlen,
-                            options.connection_timeout) >= 0) {
+                            timeout_ms) >= 0) {
                                 /* Successful connection. */
                                 memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen);
                                 break;
@@ -386,13 +400,15 @@ ssh_connect(const char *host, struct sockaddr_storage * hostaddr,
         debug("Connection established.");
 
         /* Set SO_KEEPALIVE if requested. */
-        if (options.tcp_keep_alive &&
+        if (want_keepalive &&
             setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (void *)&on,
             sizeof(on)) < 0)
                 error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
 
         /* Set the connection. */
-        packet_set_connection(sock, sock, options.setuptimeout);
+        packet_set_connection(sock, sock);
+        packet_set_timeout(options.server_alive_interval,
+            options.server_alive_count_max);
 
         return 0;
 }
@@ -402,7 +418,7 @@ ssh_connect(const char *host, struct sockaddr_storage * hostaddr,
  * identification string.
  */
 static void
-ssh_exchange_identification(void)
+ssh_exchange_identification(int timeout_ms)
 {
         char buf[256], remote_version[256];     /* must be same size! */
         int remote_major, remote_minor, mismatch;
@@ -410,40 +426,44 @@ ssh_exchange_identification(void)
         int connection_out = packet_get_connection_out();
         int minor1 = PROTOCOL_MINOR_1;
         u_int i, n;
-        struct sigaction sa, osa;
+        size_t len;
+        int fdsetsz, remaining, rc;
+        struct timeval t_start, t_remaining;
+        fd_set *fdset;
+
+        fdsetsz = howmany(connection_in + 1, NFDBITS) * sizeof(fd_mask);
+        fdset = xcalloc(1, fdsetsz);
 
-        /* Read other side's version identification.
-         * If SetupTimeOut has been set, give up after the specified amount
-         * of time.
-         */
-        if (options.setuptimeout > 0) {
-                memset(&sa, 0, sizeof(sa));
-                sa.sa_handler = banner_alarm_catch;
-                /* throw away any pending alarms, since we'd block otherwise */
-                alarm(0);
-                sigaction(SIGALRM, &sa, &osa);
-                alarm(options.setuptimeout);
-        }
         /* Read other side's version identification. */
+        remaining = timeout_ms;
         for (n = 0;;) {
-                for (i = 0; i < sizeof(buf) - 1; ) {
-                        ssize_t len = read(connection_in, &buf[i], 1);
-                        if (banner_timedout)
-                                fatal("ssh_exchange_identification: Timeout waiting for version information.");
-                        if (len == 0)
-                                errno = EPIPE;
+                for (i = 0; i < sizeof(buf) - 1; i++) {
+                        if (timeout_ms > 0) {
+                                gettimeofday(&t_start, NULL);
+                                ms_to_timeval(&t_remaining, remaining);
+                                FD_SET(connection_in, fdset);
+                                rc = select(connection_in + 1, fdset, NULL,
+                                    fdset, &t_remaining);
+                                ms_subtract_diff(&t_start, &remaining);
+                                if (rc == 0 || remaining <= 0)
+                                        fatal("Connection timed out during "
+                                            "banner exchange");
+                                if (rc == -1) {
+                                        if (errno == EINTR)
+                                                continue;
+                                        fatal("ssh_exchange_identification: "
+                                            "select: %s", strerror(errno));
+                                }
+                        }
+
+                        len = atomicio(read, connection_in, &buf[i], 1);
 
                         if (len != 1 && errno == EPIPE)
-                                fatal("ssh_exchange_identification: Connection closed by remote host");
-                        else if (len != 1) {
-#ifdef EWOULDBLOCK
-                                if (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK)
-#else
-                                if (errno == EINTR || errno == EAGAIN)
-#endif
-                                        continue;
-                                fatal("ssh_exchange_identification: read: %.100s", strerror(errno));
-                        }
+                                fatal("ssh_exchange_identification: "
+                                    "Connection closed by remote host");
+                        else if (len != 1)
+                                fatal("ssh_exchange_identification: "
+                                    "read: %.100s", strerror(errno));
                         if (buf[i] == '\r') {
                                 buf[i] = '\n';
                                 buf[i + 1] = 0;
@@ -453,13 +473,9 @@ ssh_exchange_identification(void)
                                 buf[i + 1] = 0;
                                 break;
                         }
-                        if (buf[i] == '\r') {
-                                buf[i] = '\n';
-                                buf[i + 1] = 0;         /**XXX wait for \n */
-                        }
                         if (++n > 65536)
-                                fatal("ssh_exchange_identification: No banner received");
-                        i++;
+                                fatal("ssh_exchange_identification: "
+                                    "No banner received");
                 }
                 buf[sizeof(buf) - 1] = 0;
                 if (strncmp(buf, "SSH-", 4) == 0)
@@ -467,14 +483,7 @@ ssh_exchange_identification(void)
                 debug("ssh_exchange_identification: %s", buf);
         }
         server_version_string = xstrdup(buf);
-
-        /* If SetupTimeOut has been set, unset the alarm now, and
-         * put the correct handler for SIGALRM back.
-         */
-        if (options.setuptimeout > 0) {
-                alarm(0);
-                sigaction(SIGALRM, &osa, NULL);
-        }
+        xfree(fdset);
 
         /*
          * Check that the versions match.  In future this might accept
@@ -528,10 +537,10 @@ ssh_exchange_identification(void)
                     (options.protocol & SSH_PROTO_2) ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1,
                     remote_major);
         /* Send our own protocol version identification. */
-        snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n",
+        snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s%s",
             compat20 ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1,
             compat20 ? PROTOCOL_MINOR_2 : minor1,
-            SSH_RELEASE);
+            SSH_RELEASE, compat20 ? "\r\n" : "\n");
         if (atomicio(vwrite, connection_out, buf, strlen(buf)) != strlen(buf))
                 fatal("write: %.100s", strerror(errno));
         client_version_string = xstrdup(buf);
@@ -580,14 +589,14 @@ check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port,
         Key *file_key;
         const char *type = key_type(host_key);
         char *ip = NULL, *host = NULL;
-        char hostline[1000], *hostp, *fp;
+        char hostline[1000], *hostp, *fp, *ra;
         HostStatus host_status;
         HostStatus ip_status;
         int r, local = 0, host_ip_differ = 0;
         int salen;
         char ntop[NI_MAXHOST];
         char msg[1024];
-        int len, host_line, ip_line;
+        int len, host_line, ip_line, cancelled_forwarding = 0;
         const char *host_file = NULL, *ip_file = NULL;
 
         /*
@@ -634,6 +643,7 @@ check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port,
         } else {
                 ip = xstrdup("<no hostip for proxy command>");
         }
+
         /*
          * Turn off check_host_ip if the connection is to localhost, via proxy
          * command or if we don't have a hostname to compare with
@@ -718,6 +728,13 @@ check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port,
                                 logit("Warning: Permanently added the %s host "
                                     "key for IP address '%.128s' to the list "
                                     "of known hosts.", type, ip);
+                } else if (options.visual_host_key) {
+                        fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
+                        ra = key_fingerprint(host_key, SSH_FP_MD5,
+                            SSH_FP_RANDOMART);
+                        logit("Host key fingerprint is %s\n%s\n", fp, ra);
+                        xfree(ra);
+                        xfree(fp);
                 }
                 break;
         case HOST_NEW:
@@ -753,6 +770,8 @@ check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port,
                                 snprintf(msg1, sizeof(msg1), ".");
                         /* The default */
                         fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
+                        ra = key_fingerprint(host_key, SSH_FP_MD5,
+                            SSH_FP_RANDOMART);
                         msg2[0] = '\0';
                         if (options.verify_host_key_dns) {
                                 if (matching_host_key_dns)
@@ -767,10 +786,14 @@ check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port,
                         snprintf(msg, sizeof(msg),
                             "The authenticity of host '%.200s (%s)' can't be "
                             "established%s\n"
-                            "%s key fingerprint is %s.\n%s"
+                            "%s key fingerprint is %s.%s%s\n%s"
                             "Are you sure you want to continue connecting "
                             "(yes/no)? ",
-                            host, ip, msg1, type, fp, msg2);
+                            host, ip, msg1, type, fp,
+                            options.visual_host_key ? "\n" : "",
+                            options.visual_host_key ? ra : "",
+                            msg2);
+                        xfree(ra);
                         xfree(fp);
                         if (!confirm(msg))
                                 goto fail;
@@ -823,7 +846,7 @@ check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port,
                         error("@       WARNING: POSSIBLE DNS SPOOFING DETECTED!          @");
                         error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
                         error("The %s host key for %s has changed,", type, host);
-                        error("and the key for the according IP address %s", ip);
+                        error("and the key for the corresponding IP address %s", ip);
                         error("%s. This could either mean that", key_msg);
                         error("DNS SPOOFING is happening or the IP address for the host");
                         error("and its host key have changed at the same time.");
@@ -855,27 +878,32 @@ check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port,
                         error("Password authentication is disabled to avoid "
                             "man-in-the-middle attacks.");
                         options.password_authentication = 0;
+                        cancelled_forwarding = 1;
                 }
                 if (options.kbd_interactive_authentication) {
                         error("Keyboard-interactive authentication is disabled"
                             " to avoid man-in-the-middle attacks.");
                         options.kbd_interactive_authentication = 0;
                         options.challenge_response_authentication = 0;
+                        cancelled_forwarding = 1;
                 }
                 if (options.challenge_response_authentication) {
                         error("Challenge/response authentication is disabled"
                             " to avoid man-in-the-middle attacks.");
                         options.challenge_response_authentication = 0;
+                        cancelled_forwarding = 1;
                 }
                 if (options.forward_agent) {
                         error("Agent forwarding is disabled to avoid "
                             "man-in-the-middle attacks.");
                         options.forward_agent = 0;
+                        cancelled_forwarding = 1;
                 }
                 if (options.forward_x11) {
                         error("X11 forwarding is disabled to avoid "
                             "man-in-the-middle attacks.");
                         options.forward_x11 = 0;
+                        cancelled_forwarding = 1;
                 }
                 if (options.num_local_forwards > 0 ||
                     options.num_remote_forwards > 0) {
@@ -883,12 +911,18 @@ check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port,
                             "man-in-the-middle attacks.");
                         options.num_local_forwards =
                             options.num_remote_forwards = 0;
+                        cancelled_forwarding = 1;
                 }
                 if (options.tun_open != SSH_TUNMODE_NO) {
                         error("Tunnel forwarding is disabled to avoid "
                             "man-in-the-middle attacks.");
                         options.tun_open = SSH_TUNMODE_NO;
+                        cancelled_forwarding = 1;
                 }
+                if (options.exit_on_forward_failure && cancelled_forwarding)
+                        fatal("Error: forwarding disabled due to host key "
+                            "check failure");
+                
                 /*
                  * XXX Should permit the user to change to use the new id.
                  * This could be done by converting the host key to an
@@ -987,7 +1021,7 @@ verify_host_key(char *host, struct sockaddr *hostaddr, Key *host_key)
  */
 void
 ssh_login(Sensitive *sensitive, const char *orighost,
-    struct sockaddr *hostaddr, struct passwd *pw)
+    struct sockaddr *hostaddr, struct passwd *pw, int timeout_ms)
 {
         char *host, *cp;
         char *server_user, *local_user;
@@ -1002,7 +1036,7 @@ ssh_login(Sensitive *sensitive, const char *orighost,
                         *cp = (char)tolower(*cp);
 
         /* Exchange protocol version identification strings with the server. */
-        ssh_exchange_identification();
+        ssh_exchange_identification(timeout_ms);
 
         /* Put the connection into non-blocking mode. */
         packet_set_nonblocking();
@@ -1041,18 +1075,20 @@ static int
 show_key_from_file(const char *file, const char *host, int keytype)
 {
         Key *found;
-        char *fp;
+        char *fp, *ra;
         int line, ret;
 
         found = key_new(keytype);
         if ((ret = lookup_key_in_hostfile_by_type(file, host,
             keytype, found, &line))) {
                 fp = key_fingerprint(found, SSH_FP_MD5, SSH_FP_HEX);
+                ra = key_fingerprint(found, SSH_FP_MD5, SSH_FP_RANDOMART);
                 logit("WARNING: %s key found for host %s\n"
                     "in %s:%d\n"
-                    "%s key fingerprint %s.",
+                    "%s key fingerprint %s.\n%s\n",
                     key_type(found), host, file, line,
-                    key_type(found), fp);
+                    key_type(found), fp, ra);
+                xfree(ra);
                 xfree(fp);
         }
         key_free(found);