plugins/sslutils.c

   1 /*****************************************************************************
   2 *
   3 * Nagios plugins SSL utilities
   4 *
   5 * License: GPL
   6 * Copyright (c) 2005-2010 Nagios Plugins Development Team
   7 *
   8 * Description:
   9 *
  10 * This file contains common functions for plugins that require SSL.
  11 *
  12 *
  13 * This program is free software: you can redistribute it and/or modify
  14 * it under the terms of the GNU General Public License as published by
  15 * the Free Software Foundation, either version 3 of the License, or
  16 * (at your option) any later version.
  17 *
  18 * This program is distributed in the hope that it will be useful,
  19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21 * GNU General Public License for more details.
  22 *
  23 * You should have received a copy of the GNU General Public License
  24 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  25 *
  26 *
  27 *****************************************************************************/
  28
  29 #define MAX_CN_LENGTH 256
  30 #define LOCAL_TIMEOUT_ALARM_HANDLER
  31 #include "common.h"
  32 #include "netutils.h"
  33
  34 #ifdef HAVE_SSL
  35 static SSL_CTX *c=NULL;
  36 static SSL *s=NULL;
  37 static int initialized=0;
  38
  39 int np_net_ssl_init (int sd) {
  40                 return np_net_ssl_init_with_hostname(sd, NULL);
  41 }
  42
  43 int np_net_ssl_init_with_hostname (int sd, char *host_name) {
  44                 if (!initialized) {
  45                         /* Initialize SSL context */
  46                         SSLeay_add_ssl_algorithms ();
  47                         SSL_load_error_strings ();
  48                         OpenSSL_add_all_algorithms ();
  49                         initialized = 1;
  50                 }
  51                 if ((c = SSL_CTX_new (SSLv23_client_method ())) == NULL) {
  52                                 printf ("%s\n", _("CRITICAL - Cannot create SSL context."));
  53                                 return STATE_CRITICAL;
  54                 }
  55                 if ((s = SSL_new (c)) != NULL){
  56 #ifdef SSL_set_tlsext_host_name
  57                                 if (host_name != NULL)
  58                                         SSL_set_tlsext_host_name(s, host_name);
  59 #endif
  60                                 SSL_set_fd (s, sd);
  61                                 if (SSL_connect(s) == 1){
  62                                                 return OK;
  63                                 } else {
  64                                                 printf ("%s\n", _("CRITICAL - Cannot make SSL connection "));
  65 #  ifdef USE_OPENSSL /* XXX look into ERR_error_string */
  66                                                 ERR_print_errors_fp (stdout);
  67 #  endif /* USE_OPENSSL */
  68                                 }
  69                 } else {
  70                                 printf ("%s\n", _("CRITICAL - Cannot initiate SSL handshake."));
  71                 }
  72                 return STATE_CRITICAL;
  73 }
  74
  75 void np_net_ssl_cleanup (){
  76                 if(s){
  77 #ifdef SSL_set_tlsext_host_name
  78                                 SSL_set_tlsext_host_name(s, NULL);
  79 #endif
  80                                 SSL_shutdown (s);
  81                                 SSL_free (s);
  82                                 if(c) {
  83                                         SSL_CTX_free (c);
  84                                         c=NULL;
  85                                 }
  86                                 s=NULL;
  87                 }
  88 }
  89
  90 int np_net_ssl_write(const void *buf, int num){
  91         return SSL_write(s, buf, num);
  92 }
  93
  94 int np_net_ssl_read(void *buf, int num){
  95         return SSL_read(s, buf, num);
  96 }
  97
  98 int np_net_ssl_check_cert(int days_till_exp){
  99 #  ifdef USE_OPENSSL
 100         X509 *certificate=NULL;
 101         X509_NAME *subj=NULL;
 102         char cn[MAX_CN_LENGTH]= "";
 103         int cnlen =-1;
 104         int status=STATE_UNKNOWN;
 105
 106         ASN1_STRING *tm;
 107         int offset;
 108         struct tm stamp;
 109         float time_left;
 110         int days_left;
 111         char timestamp[17] = "";
 112
 113         certificate=SSL_get_peer_certificate(s);
 114         if(! certificate){
 115                 printf ("%s\n",_("CRITICAL - Cannot retrieve server certificate."));
 116                 return STATE_CRITICAL;
 117         }
 118
 119         /* Extract CN from certificate subject */
 120         subj=X509_get_subject_name(certificate);
 121
 122         if(! subj){
 123                 printf ("%s\n",_("CRITICAL - Cannot retrieve certificate subject."));
 124                 return STATE_CRITICAL;
 125         }
 126         cnlen = X509_NAME_get_text_by_NID (subj, NID_commonName, cn, sizeof(cn));
 127         if ( cnlen == -1 )
 128                 strcpy(cn , _("Unknown CN"));
 129
 130         /* Retrieve timestamp of certificate */
 131         tm = X509_get_notAfter (certificate);
 132
 133         /* Generate tm structure to process timestamp */
 134         if (tm->type == V_ASN1_UTCTIME) {
 135                 if (tm->length < 10) {
 136                         printf ("%s\n", _("CRITICAL - Wrong time format in certificate."));
 137                         return STATE_CRITICAL;
 138                 } else {
 139                         stamp.tm_year = (tm->data[0] - '0') * 10 + (tm->data[1] - '0');
 140                         if (stamp.tm_year < 50)
 141                                 stamp.tm_year += 100;
 142                         offset = 0;
 143                 }
 144         } else {
 145                 if (tm->length < 12) {
 146                         printf ("%s\n", _("CRITICAL - Wrong time format in certificate."));
 147                         return STATE_CRITICAL;
 148                 } else {
 149                         stamp.tm_year =
 150                                 (tm->data[0] - '0') * 1000 + (tm->data[1] - '0') * 100 +
 151                                 (tm->data[2] - '0') * 10 + (tm->data[3] - '0');
 152                         stamp.tm_year -= 1900;
 153                         offset = 2;
 154                 }
 155         }
 156         stamp.tm_mon =
 157                 (tm->data[2 + offset] - '0') * 10 + (tm->data[3 + offset] - '0') - 1;
 158         stamp.tm_mday =
 159                 (tm->data[4 + offset] - '0') * 10 + (tm->data[5 + offset] - '0');
 160         stamp.tm_hour =
 161                 (tm->data[6 + offset] - '0') * 10 + (tm->data[7 + offset] - '0');
 162         stamp.tm_min =
 163                 (tm->data[8 + offset] - '0') * 10 + (tm->data[9 + offset] - '0');
 164         stamp.tm_sec = 0;
 165         stamp.tm_isdst = -1;
 166
 167         time_left = difftime(timegm(&stamp), time(NULL));
 168         days_left = time_left / 86400;
 169         snprintf
 170                 (timestamp, 17, "%02d/%02d/%04d %02d:%02d",
 171                  stamp.tm_mon + 1,
 172                  stamp.tm_mday, stamp.tm_year + 1900, stamp.tm_hour, stamp.tm_min);
 173
 174         if (days_left > 0 && days_left <= days_till_exp) {
 175                 printf (_("WARNING - Certificate '%s' expires in %d day(s) (%s).\n"), cn, days_left, timestamp);
 176                 status=STATE_WARNING;
 177         } else if (time_left < 0) {
 178                 printf (_("CRITICAL - Certificate '%s' expired on %s.\n"), cn, timestamp);
 179                 status=STATE_CRITICAL;
 180         } else if (days_left == 0) {
 181                 printf (_("WARNING - Certificate '%s' expires today (%s).\n"), cn, timestamp);
 182                 status=STATE_WARNING;
 183         } else {
 184                 printf (_("OK - Certificate '%s' will expire on %s.\n"), cn, timestamp);
 185                 status=STATE_OK;
 186         }
 187         X509_free (certificate);
 188         return status;
 189 #  else /* ifndef USE_OPENSSL */
 190         printf ("%s\n", _("WARNING - Plugin does not support checking certificates."));
 191         return STATE_WARNING;
 192 #  endif /* USE_OPENSSL */
 193 }
 194
 195 #endif /* HAVE_SSL */