plugins/sslutils.c

   1 /*****************************************************************************
   2 *
   3 * Nagios plugins SSL utilities
   4 *
   5 * License: GPL
   6 * Copyright (c) 2005-2007 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 LOCAL_TIMEOUT_ALARM_HANDLER
  30 #include "common.h"
  31 #include "netutils.h"
  32
  33 #ifdef HAVE_SSL
  34 static SSL_CTX *c=NULL;
  35 static SSL *s=NULL;
  36 static int initialized=0;
  37
  38 int np_net_ssl_init (int sd) {
  39                 return np_net_ssl_init_with_hostname(sd, NULL);
  40 }
  41
  42 int np_net_ssl_init_with_hostname (int sd, char *host_name) {
  43                 if (!initialized) {
  44                         /* Initialize SSL context */
  45                         SSLeay_add_ssl_algorithms ();
  46                         SSL_load_error_strings ();
  47                         OpenSSL_add_all_algorithms ();
  48                         initialized = 1;
  49                 }
  50                 if ((c = SSL_CTX_new (SSLv23_client_method ())) == NULL) {
  51                                 printf ("%s\n", _("CRITICAL - Cannot create SSL context."));
  52                                 return STATE_CRITICAL;
  53                 }
  54                 if ((s = SSL_new (c)) != NULL){
  55 #ifdef SSL_set_tlsext_host_name
  56                                 if (host_name != NULL)
  57                                         SSL_set_tlsext_host_name(s, host_name);
  58 #endif
  59                                 SSL_set_fd (s, sd);
  60                                 if (SSL_connect(s) == 1){
  61                                                 return OK;
  62                                 } else {
  63                                                 printf ("%s\n", _("CRITICAL - Cannot make SSL connection "));
  64 #  ifdef USE_OPENSSL /* XXX look into ERR_error_string */
  65                                                 ERR_print_errors_fp (stdout);
  66 #  endif /* USE_OPENSSL */
  67                                 }
  68                 } else {
  69                                 printf ("%s\n", _("CRITICAL - Cannot initiate SSL handshake."));
  70                 }
  71                 return STATE_CRITICAL;
  72 }
  73
  74 void np_net_ssl_cleanup (){
  75                 if(s){
  76 #ifdef SSL_set_tlsext_host_name
  77                                 SSL_set_tlsext_host_name(s, NULL);
  78 #endif
  79                                 SSL_shutdown (s);
  80                                 SSL_free (s);
  81                                 if(c) {
  82                                         SSL_CTX_free (c);
  83                                         c=NULL;
  84                                 }
  85                                 s=NULL;
  86                 }
  87 }
  88
  89 int np_net_ssl_write(const void *buf, int num){
  90         return SSL_write(s, buf, num);
  91 }
  92
  93 int np_net_ssl_read(void *buf, int num){
  94         return SSL_read(s, buf, num);
  95 }
  96
  97 int np_net_ssl_check_cert(int days_till_exp){
  98 #  ifdef USE_OPENSSL
  99         X509 *certificate=NULL;
 100         ASN1_STRING *tm;
 101         int offset;
 102         struct tm stamp;
 103         float time_left;
 104         int days_left;
 105         char timestamp[17] = "";
 106
 107         certificate=SSL_get_peer_certificate(s);
 108         if(! certificate){
 109                 printf ("%s\n",_("CRITICAL - Cannot retrieve server certificate."));
 110                 return STATE_CRITICAL;
 111         }
 112
 113         /* Retrieve timestamp of certificate */
 114         tm = X509_get_notAfter (certificate);
 115
 116         /* Generate tm structure to process timestamp */
 117         if (tm->type == V_ASN1_UTCTIME) {
 118                 if (tm->length < 10) {
 119                         printf ("%s\n", _("CRITICAL - Wrong time format in certificate."));
 120                         return STATE_CRITICAL;
 121                 } else {
 122                         stamp.tm_year = (tm->data[0] - '0') * 10 + (tm->data[1] - '0');
 123                         if (stamp.tm_year < 50)
 124                                 stamp.tm_year += 100;
 125                         offset = 0;
 126                 }
 127         } else {
 128                 if (tm->length < 12) {
 129                         printf ("%s\n", _("CRITICAL - Wrong time format in certificate."));
 130                         return STATE_CRITICAL;
 131                 } else {
 132                         stamp.tm_year =
 133                                 (tm->data[0] - '0') * 1000 + (tm->data[1] - '0') * 100 +
 134                                 (tm->data[2] - '0') * 10 + (tm->data[3] - '0');
 135                         stamp.tm_year -= 1900;
 136                         offset = 2;
 137                 }
 138         }
 139         stamp.tm_mon =
 140                 (tm->data[2 + offset] - '0') * 10 + (tm->data[3 + offset] - '0') - 1;
 141         stamp.tm_mday =
 142                 (tm->data[4 + offset] - '0') * 10 + (tm->data[5 + offset] - '0');
 143         stamp.tm_hour =
 144                 (tm->data[6 + offset] - '0') * 10 + (tm->data[7 + offset] - '0');
 145         stamp.tm_min =
 146                 (tm->data[8 + offset] - '0') * 10 + (tm->data[9 + offset] - '0');
 147         stamp.tm_sec = 0;
 148         stamp.tm_isdst = -1;
 149
 150         time_left = difftime(timegm(&stamp), time(NULL));
 151         days_left = time_left / 86400;
 152         snprintf
 153                 (timestamp, 17, "%02d/%02d/%04d %02d:%02d",
 154                  stamp.tm_mon + 1,
 155                  stamp.tm_mday, stamp.tm_year + 1900, stamp.tm_hour, stamp.tm_min);
 156
 157         if (days_left > 0 && days_left <= days_till_exp) {
 158                 printf (_("WARNING - Certificate expires in %d day(s) (%s).\n"), days_left, timestamp);
 159                 return STATE_WARNING;
 160         } else if (time_left < 0) {
 161                 printf (_("CRITICAL - Certificate expired on %s.\n"), timestamp);
 162                 return STATE_CRITICAL;
 163         } else if (days_left == 0) {
 164                 printf (_("WARNING - Certificate expires today (%s).\n"), timestamp);
 165                 return STATE_WARNING;
 166         }
 167
 168         printf (_("OK - Certificate will expire on %s.\n"), timestamp);
 169         X509_free (certificate);
 170         return STATE_OK;
 171 #  else /* ifndef USE_OPENSSL */
 172         printf ("%s\n", _("WARNING - Plugin does not support checking certificates."));
 173         return STATE_WARNING;
 174 #  endif /* USE_OPENSSL */
 175 }
 176
 177 #endif /* HAVE_SSL */