2 files changed, 234 insertions, 76 deletions

diff --git a/plugins/check_ssh.c b/plugins/check_ssh.c
index 4eb746c..34ef37b 100644
--- a/plugins/check_ssh.c
+++ b/plugins/check_ssh.c
@@ -1,39 +1,39 @@
 /*****************************************************************************
-* 
+*
 * 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";
 const char *copyright = "2000-2007";
 const char *email = "devel@monitoring-plugins.org";
 
-#include "common.h"
-#include "netutils.h"
+#include "./common.h"
+#include "./netutils.h"
 #include "utils.h"
 
 #ifndef MSG_DONTWAIT
@@ -105,7 +105,7 @@ 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}
         };
 
@@ -214,7 +214,9 @@ ssh_connect (char *haddr, int hport, char *remote_version, char *remote_protocol
 {
         int sd;
         int result;
-        char *output = NULL;
+        int len = 0;
+        ssize_t recv_ret = 0;
+        char *version_control_string = NULL;
         char *buffer = NULL;
         char *ssh_proto = NULL;
         char *ssh_server = NULL;
@@ -229,52 +231,126 @@ ssh_connect (char *haddr, int hport, char *remote_version, char *remote_protocol
         if (result != STATE_OK)
                 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);
+        char *output = (char *) calloc (BUFF_SZ + 1, sizeof(char));
+
+        unsigned int iteration = 0;
+        ssize_t byte_offset = 0;
+
+        while ((version_control_string == NULL) && (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;
+
+                        char *index = NULL;
+                        while ((index = strchr(output+byte_offset, '\n')) != NULL) {
+                                /*Partition the buffer so that this line is a separate string,
+                                 * by replacing the newline with NUL*/
+                                output[(index - output)] = '\0';
+                                len = strlen(output + byte_offset);
+
+                                if ((len >= 4) && (strncmp (output+byte_offset, "SSH-", 4) == 0)) {
+                                        /*if the string starts with SSH-, this _should_ be a valid version control string*/
+                                                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 == NULL) {
+                                /* 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;
+                }
+        }
+
+        if (recv_ret < 0) {
+                printf("SSH CRITICAL - %s", strerror(errno));
+                exit(STATE_CRITICAL);
+        }
+
+        if (version_control_string == NULL) {
+                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)*/
+        char *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",
+                        (_("SSH CRITICAL - %s (protocol %s) protocol version mismatch, expected '%s' | %s\n"),
+                         ssh_server, ssh_proto, remote_protocol, fperfdata("time", elapsed_time, "s",
                          false, 0, false, 0, true, 0, true, (int)socket_timeout));
                 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);
 }
 
 
@@ -292,7 +368,7 @@ 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 ();
 
@@ -306,10 +382,10 @@ 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);
 
@@ -321,7 +397,7 @@ 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);
 }
 
diff --git a/plugins/t/check_ssh.t b/plugins/t/check_ssh.t
index a5cd23c..907d33a 100644
--- a/plugins/t/check_ssh.t
+++ b/plugins/t/check_ssh.t
@@ -8,34 +8,116 @@ use strict;
 use Test::More;
 use NPTest;
 
+my $res;
+
 # Required parameters
-my $ssh_host           = getTestParameter("NP_SSH_HOST", "A host providing SSH service", "localhost");
-my $host_nonresponsive = getTestParameter("NP_HOST_NONRESPONSIVE", "The hostname of system not responsive to network requests", "10.0.0.1" );
-my $hostname_invalid   = getTestParameter("NP_HOSTNAME_INVALID", "An invalid (not known to DNS) hostname", "nosuchhost" );
+my $ssh_host           = getTestParameter("NP_SSH_HOST",
+                                          "A host providing SSH service",
+                                          "localhost");
+
+my $host_nonresponsive = getTestParameter("NP_HOST_NONRESPONSIVE",
+                                          "The hostname of system not responsive to network requests",
+                                          "10.0.0.1" );
+
+my $hostname_invalid   = getTestParameter("NP_HOSTNAME_INVALID",
+                                          "An invalid (not known to DNS) hostname",
+                                          "nosuchhost" );
+
+
+plan tests => 14 + 6;
+
+SKIP: {
+        skip "SSH_HOST must be defined", 6 unless $ssh_host;
+        my $result = NPTest->testCmd(
+                "./check_ssh -H $ssh_host"
+                );
+        cmp_ok($result->return_code, '==', 0, "Exit with return code 0 (OK)");
+        like($result->output, '/^SSH OK - /', "Status text if command returned none (OK)");
+
+
+        $result = NPTest->testCmd(
+                "./check_ssh -H $host_nonresponsive -t 2"
+                );
+        cmp_ok($result->return_code, '==', 2, "Exit with return code 0 (OK)");
+        like($result->output, '/^CRITICAL - Socket timeout after 2 seconds/', "Status text if command returned none (OK)");
+
+
+
+        $result = NPTest->testCmd(
+                "./check_ssh -H $hostname_invalid -t 2"
+                );
+        cmp_ok($result->return_code, '==', 3, "Exit with return code 0 (OK)");
+        like($result->output, '/^check_ssh: Invalid hostname/', "Status text if command returned none (OK)");
+
 
+}
+SKIP: {
 
-plan skip_all => "SSH_HOST must be defined" unless $ssh_host;
-plan tests    => 6;
+        skip "No netcat available", 14 unless (system("which nc > /dev/null") == 0);
 
+        # netcat on linux (on debian) will just keep the socket open if not advised otherwise
+        # therefore we add -q to close it after two seconds after receiving the EOF from input
+        my $nc_flags = "-l 5003 -N";
+        #A valid protocol version control string has the form
+        #       SSH-protoversion-softwareversion SP comments CR LF
+        #
+        # where `comments` is optional, protoversion is the SSH protocol version and
+        # softwareversion is an arbitrary string representing the server software version
+        open(NC, "echo 'SSH-2.0-nagiosplug.ssh.0.1' | nc ${nc_flags}|");
+        sleep 0.1;
+        $res = NPTest->testCmd( "./check_ssh -H localhost -p 5003" );
+        cmp_ok( $res->return_code, '==', 0, "Got SSH protocol version control string");
+        like( $res->output, '/^SSH OK - nagiosplug.ssh.0.1 \(protocol 2.0\)/', "Output OK");
+        close NC;
 
-my $result = NPTest->testCmd(
-    "./check_ssh -H $ssh_host"
-    );
-cmp_ok($result->return_code, '==', 0, "Exit with return code 0 (OK)");
-like($result->output, '/^SSH OK - /', "Status text if command returned none (OK)");
+        open(NC, "echo 'SSH-2.0-3.2.9.1' | nc ${nc_flags}|");
+        sleep 0.1;
+        $res = NPTest->testCmd( "./check_ssh -H localhost -p 5003" );
+        cmp_ok( $res->return_code, "==", 0, "Got SSH protocol version control string with non-alpha softwareversion string");
+        like( $res->output, '/^SSH OK - 3.2.9.1 \(protocol 2.0\)/', "Output OK for non-alpha softwareversion string");
+        close NC;
 
+        open(NC, "echo 'SSH-2.0-nagiosplug.ssh.0.1 this is a comment' | nc ${nc_flags} |");
+        sleep 0.1;
+        $res = NPTest->testCmd( "./check_ssh -H localhost -p 5003 -r nagiosplug.ssh.0.1" );
+        cmp_ok( $res->return_code, '==', 0, "Got SSH protocol version control string, and parsed comment appropriately");
+        like( $res->output, '/^SSH OK - nagiosplug.ssh.0.1 \(protocol 2.0\)/', "Output OK");
+        close NC;
 
-$result = NPTest->testCmd(
-    "./check_ssh -H $host_nonresponsive -t 2"
-    );
-cmp_ok($result->return_code, '==', 2, "Exit with return code 0 (OK)");
-like($result->output, '/^CRITICAL - Socket timeout after 2 seconds/', "Status text if command returned none (OK)");
+        open(NC, "echo 'SSH-' | nc ${nc_flags}|");
+        sleep 0.1;
+        $res = NPTest->testCmd( "./check_ssh -H localhost -p 5003" );
+        cmp_ok( $res->return_code, '==', 2, "Got invalid SSH protocol version control string");
+        like( $res->output, '/^SSH CRITICAL/', "Output OK");
+        close NC;
 
+        open(NC, "echo '' | nc ${nc_flags}|");
+        sleep 0.1;
+        $res = NPTest->testCmd( "./check_ssh -H localhost -p 5003" );
+        cmp_ok( $res->return_code, '==', 2, "No version control string received");
+        like( $res->output, '/^SSH CRITICAL - No version control string received/', "Output OK");
+        close NC;
 
+        open(NC, "echo 'Not a version control string' | nc ${nc_flags}|");
+        sleep 0.1;
+        $res = NPTest->testCmd( "./check_ssh -H localhost -p 5003" );
+        cmp_ok( $res->return_code, '==', 2, "No version control string received");
+        like( $res->output, '/^SSH CRITICAL - No version control string received/', "Output OK");
+        close NC;
 
-$result = NPTest->testCmd(
-    "./check_ssh -H $hostname_invalid -t 2"
-    );
-cmp_ok($result->return_code, '==', 3, "Exit with return code 0 (OK)");
-like($result->output, '/^check_ssh: Invalid hostname/', "Status text if command returned none (OK)");
 
+        #RFC 4253 permits servers to send any number of data lines prior to sending the protocol version control string
+        open(NC, "{ echo 'AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA'; sleep 0.5;
+                echo 'BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB'; sleep 0.5;
+                echo 'CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC'; sleep 0.2;
+                echo 'DDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD'; sleep 0.3;
+                printf 'EEEEEEEEEEEEEEEEEE'; sleep 0.2;
+                printf 'EEEEEEEEEEEEEEEEEE\n'; sleep 0.2;
+                echo 'Some\nPrepended\nData\nLines\n'; sleep 0.2;
+                echo 'SSH-2.0-nagiosplug.ssh.0.2';} | nc ${nc_flags}|");
+        sleep 0.1;
+        $res = NPTest->testCmd( "./check_ssh -H localhost -p 5003" );
+        cmp_ok( $res->return_code, '==', 0, "Got delayed SSH protocol version control string");
+        like( $res->output, '/^SSH OK - nagiosplug.ssh.0.2 \(protocol 2.0\)/', "Output OK");
+        close NC;
+}