1 files changed, 125 insertions, 53 deletions

diff --git a/plugins/check_ssh.c b/plugins/check_ssh.c
index 8ccbd5a..0515065 100644
--- a/plugins/check_ssh.c
+++ b/plugins/check_ssh.c
@@ -1,31 +1,31 @@
 /*****************************************************************************
-* 
+*
 * Monitoring check_ssh plugin
-* 
+*
 * License: GPL
 * Copyright (c) 2000-2007 Monitoring Plugins Development Team
-* 
+*
 * Description:
-* 
+*
 * This file contains the check_ssh plugin
-* 
+*
 * Try to connect to an SSH server at specified server and port
-* 
-* 
+*
+*
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
-* 
+*
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
-* 
+*
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
-* 
-* 
+*
+*
 *****************************************************************************/
 
 const char *progname = "check_ssh";
@@ -106,7 +106,7 @@ process_arguments (int argc, char **argv)
                 {"timeout", required_argument, 0, 't'},
                 {"verbose", no_argument, 0, 'v'},
                 {"remote-version", required_argument, 0, 'r'},
-                {"remote-protcol", required_argument, 0, 'P'},
+                {"remote-protocol", required_argument, 0, 'P'},
                 {0, 0, 0, 0}
         };
 
@@ -215,8 +215,13 @@ ssh_connect (char *haddr, int hport, char *remote_version, char *remote_protocol
 {
         int sd;
         int result;
+        int len = 0;
+        ssize_t byte_offset = 0;
+        ssize_t recv_ret = 0;
+        char *version_control_string = NULL;
         char *output = NULL;
         char *buffer = NULL;
+        char *tmp= NULL;
         char *ssh_proto = NULL;
         char *ssh_server = NULL;
         static char *rev_no = VERSION;
@@ -231,51 +236,118 @@ ssh_connect (char *haddr, int hport, char *remote_version, char *remote_protocol
                 return result;
 
         output = (char *) malloc (BUFF_SZ + 1);
-        memset (output, 0, BUFF_SZ + 1);
-        recv (sd, output, BUFF_SZ, 0);
-        if (strncmp (output, "SSH", 3)) {
-                printf (_("Server answer: %s"), output);
-                close(sd);
+        memset(output, 0, BUFF_SZ+1);
+        while (!version_control_string && (recv_ret = recv(sd, output+byte_offset, BUFF_SZ - byte_offset, 0)) > 0) {
+                if (strchr(output, '\n')) { /* we've got at least one full line, start parsing*/
+                        byte_offset = 0;
+                        while (strchr(output+byte_offset, '\n') != NULL) {
+                                /*Partition the buffer so that this line is a separate string,
+                                 * by replacing the newline with NUL*/
+                                output[(strchr(output+byte_offset, '\n')-output)]= '\0';
+                                len = strlen(output+byte_offset);
+                                if (len >= 4) {
+                                        /*if the string starts with SSH-, this _should_ be a valid version control string*/
+                                        if (strncmp (output+byte_offset, "SSH-", 4) == 0) {
+                                                version_control_string = output+byte_offset;
+                                                break;
+                                        }
+                                }
+
+                                /*the start of the next line (if one exists) will be after the current one (+ NUL)*/
+                                byte_offset+=len+1;
+                        }
+                        if(!version_control_string) {
+                                /* move unconsumed data to beginning of buffer, null rest */
+                                memmove((void *)output, (void *)output+byte_offset+1, BUFF_SZ - len+1);
+                                memset(output+byte_offset+1, 0, BUFF_SZ-byte_offset+1);
+
+                                /*start reading from end of current line chunk on next recv*/
+                                byte_offset = strlen(output);
+                        }
+                }
+                else {
+                        byte_offset += recv_ret;
+                }
+        }
+        tmp = NULL;
+        if (recv_ret < 0) {
+                printf("SSH CRITICAL - %s", strerror(errno));
+                exit(STATE_CRITICAL);
+        }
+        if (!version_control_string) {
+                printf("SSH CRITICAL - No version control string received");
+                exit(STATE_CRITICAL);
+        }
+        /*
+         * "When the connection has been established, both sides MUST send an
+         * identification string.  This identification string MUST be
+         *
+         * SSH-protoversion-softwareversion SP comments CR LF"
+         *              - RFC 4253:4.2
+         */
+        strip (version_control_string);
+        if (verbose)
+                printf ("%s\n", version_control_string);
+        ssh_proto = version_control_string + 4;
+
+        /*
+         * We assume the protoversion is of the form Major.Minor, although
+         * this is not _strictly_ required. See
+         *
+         * "Both the 'protoversion' and 'softwareversion' strings MUST consist of
+         * printable US-ASCII characters, with the exception of whitespace
+         * characters and the minus sign (-)"
+         *              - RFC 4253:4.2
+         * and,
+         *
+         * "As stated earlier, the 'protoversion' specified for this protocol is
+         * "2.0".  Earlier versions of this protocol have not been formally
+         * documented, but it is widely known that they use 'protoversion' of
+         * "1.x" (e.g., "1.5" or "1.3")."
+         *              - RFC 4253:5
+         */
+        ssh_server = ssh_proto + strspn (ssh_proto, "0123456789.") + 1; /* (+1 for the '-' separating protoversion from softwareversion) */
+
+        /* If there's a space in the version string, whatever's after the space is a comment
+         * (which is NOT part of the server name/version)*/
+        tmp = strchr(ssh_server, ' ');
+        if (tmp) {
+                ssh_server[tmp - ssh_server] = '\0';
+        }
+        if (strlen(ssh_proto) == 0 || strlen(ssh_server) == 0) {
+                printf(_("SSH CRITICAL - Invalid protocol version control string %s\n"), version_control_string);
                 exit (STATE_CRITICAL);
         }
-        else {
-                strip (output);
-                if (verbose)
-                        printf ("%s\n", output);
-                ssh_proto = output + 4;
-                ssh_server = ssh_proto + strspn (ssh_proto, "-0123456789. ");
-                ssh_proto[strspn (ssh_proto, "0123456789. ")] = 0;
-
-                xasprintf (&buffer, "SSH-%s-check_ssh_%s\r\n", ssh_proto, rev_no);
-                send (sd, buffer, strlen (buffer), MSG_DONTWAIT);
-                if (verbose)
-                        printf ("%s\n", buffer);
-
-                if (remote_version && strcmp(remote_version, ssh_server)) {
-                        printf
-                                (_("SSH CRITICAL - %s (protocol %s) version mismatch, expected '%s'\n"),
-                                 ssh_server, ssh_proto, remote_version);
-                        close(sd);
-                        exit (STATE_CRITICAL);
-                }
+        ssh_proto[strspn (ssh_proto, "0123456789. ")] = 0;
 
-                if (remote_protocol && strcmp(remote_protocol, ssh_proto)) {
-                        printf
-                                (_("SSH CRITICAL - %s (protocol %s) protocol version mismatch, expected '%s'\n"),
-                                 ssh_server, ssh_proto, remote_protocol);
-                        close(sd);
-                        exit (STATE_CRITICAL);
-                }
+        xasprintf (&buffer, "SSH-%s-check_ssh_%s\r\n", ssh_proto, rev_no);
+        send (sd, buffer, strlen (buffer), MSG_DONTWAIT);
+        if (verbose)
+                printf ("%s\n", buffer);
 
-                elapsed_time = (double)deltime(tv) / 1.0e6;
+        if (remote_version && strcmp(remote_version, ssh_server)) {
+                printf
+                        (_("SSH CRITICAL - %s (protocol %s) version mismatch, expected '%s'\n"),
+                         ssh_server, ssh_proto, remote_version);
+                close(sd);
+                exit (STATE_CRITICAL);
+        }
 
+        if (remote_protocol && strcmp(remote_protocol, ssh_proto)) {
                 printf
-                        (_("SSH OK - %s (protocol %s) | %s\n"),
-                         ssh_server, ssh_proto, fperfdata("time", elapsed_time, "s",
-                         FALSE, 0, FALSE, 0, TRUE, 0, TRUE, (int)socket_timeout));
+                        (_("SSH CRITICAL - %s (protocol %s) protocol version mismatch, expected '%s'\n"),
+                         ssh_server, ssh_proto, remote_protocol);
                 close(sd);
-                exit (STATE_OK);
+                exit (STATE_CRITICAL);
         }
+        elapsed_time = (double)deltime(tv) / 1.0e6;
+
+        printf
+                (_("SSH OK - %s (protocol %s) | %s\n"),
+                 ssh_server, ssh_proto, fperfdata("time", elapsed_time, "s",
+                         FALSE, 0, FALSE, 0, TRUE, 0, TRUE, (int)socket_timeout));
+        close(sd);
+        exit (STATE_OK);
 }
 
 
@@ -293,7 +365,7 @@ print_help (void)
 
         printf ("%s\n", _("Try to connect to an SSH server at specified server and port"));
 
-  printf ("\n\n");
+        printf ("\n\n");
 
         print_usage ();
 
@@ -307,10 +379,10 @@ print_help (void)
         printf (UT_CONN_TIMEOUT, DEFAULT_SOCKET_TIMEOUT);
 
         printf (" %s\n", "-r, --remote-version=STRING");
-  printf ("    %s\n", _("Alert if string doesn't match expected server version (ex: OpenSSH_3.9p1)"));
+        printf ("    %s\n", _("Alert if string doesn't match expected server version (ex: OpenSSH_3.9p1)"));
 
         printf (" %s\n", "-P, --remote-protocol=STRING");
-  printf ("    %s\n", _("Alert if protocol doesn't match expected protocol version (ex: 2.0)"));
+        printf ("    %s\n", _("Alert if protocol doesn't match expected protocol version (ex: 2.0)"));
 
         printf (UT_VERBOSE);
 
@@ -322,7 +394,7 @@ print_help (void)
 void
 print_usage (void)
 {
-  printf ("%s\n", _("Usage:"));
+        printf ("%s\n", _("Usage:"));
         printf ("%s  [-4|-6] [-t <timeout>] [-r <remote version>] [-p <port>] <host>\n", progname);
 }