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 /* Max length of timestamps, ex: "03/05/2009 00:13 GMT". Calculate up to 6
  34  * chars for the timezone (ex: "GMT-10") and one terminating \0 */
  35 #define TS_LENGTH 24
  36
  37 #ifdef HAVE_SSL
  38 static SSL_CTX *c=NULL;
  39 static SSL *s=NULL;
  40 static int initialized=0;
  41
  42 int np_net_ssl_init (int sd){
  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                                 SSL_set_fd (s, sd);
  56                                 if (SSL_connect(s) == 1){
  57                                                 return OK;
  58                                 } else {
  59                                                 printf ("%s\n", _("CRITICAL - Cannot make SSL connection "));
  60 #  ifdef USE_OPENSSL /* XXX look into ERR_error_string */
  61                                                 ERR_print_errors_fp (stdout);
  62 #  endif /* USE_OPENSSL */
  63                                 }
  64                 } else {
  65                                 printf ("%s\n", _("CRITICAL - Cannot initiate SSL handshake."));
  66                 }
  67                 return STATE_CRITICAL;
  68 }
  69
  70 void np_net_ssl_cleanup (){
  71                 if(s){
  72                                 SSL_shutdown (s);
  73                                 SSL_free (s);
  74                                 if(c) {
  75                                         SSL_CTX_free (c);
  76                                         c=NULL;
  77                                 }
  78                                 s=NULL;
  79                 }
  80 }
  81
  82 int np_net_ssl_write(const void *buf, int num){
  83         return SSL_write(s, buf, num);
  84 }
  85
  86 int np_net_ssl_read(void *buf, int num){
  87         return SSL_read(s, buf, num);
  88 }
  89
  90 int np_net_ssl_check_cert(int days_till_exp){
  91 #  ifdef USE_OPENSSL
  92         X509 *certificate=NULL;
  93         ASN1_STRING *tm;
  94         int offset;
  95         struct tm stamp;
  96         int days_left;
  97         char timestamp[TS_LENGTH] = "";
  98
  99         certificate=SSL_get_peer_certificate(s);
 100         if(! certificate){
 101                 printf ("%s\n",_("CRITICAL - Cannot retrieve server certificate."));
 102                 return STATE_CRITICAL;
 103         }
 104
 105         /* Retrieve timestamp of certificate */
 106         tm = X509_get_notAfter (certificate);
 107
 108         /* Generate tm structure to process timestamp */
 109         if (tm->type == V_ASN1_UTCTIME) {
 110                 if (tm->length < 10) {
 111                         printf ("%s\n", _("CRITICAL - Wrong time format in certificate."));
 112                         return STATE_CRITICAL;
 113                 } else {
 114                         stamp.tm_year = (tm->data[0] - '0') * 10 + (tm->data[1] - '0');
 115                         if (stamp.tm_year < 50)
 116                                 stamp.tm_year += 100;
 117                         offset = 0;
 118                 }
 119         } else {
 120                 if (tm->length < 12) {
 121                         printf ("%s\n", _("CRITICAL - Wrong time format in certificate."));
 122                         return STATE_CRITICAL;
 123                 } else {
 124                         stamp.tm_year =
 125                                 (tm->data[0] - '0') * 1000 + (tm->data[1] - '0') * 100 +
 126                                 (tm->data[2] - '0') * 10 + (tm->data[3] - '0');
 127                         stamp.tm_year -= 1900;
 128                         offset = 2;
 129                 }
 130         }
 131         stamp.tm_mon =
 132                 (tm->data[2 + offset] - '0') * 10 + (tm->data[3 + offset] - '0') - 1;
 133         stamp.tm_mday =
 134                 (tm->data[4 + offset] - '0') * 10 + (tm->data[5 + offset] - '0');
 135         stamp.tm_hour =
 136                 (tm->data[6 + offset] - '0') * 10 + (tm->data[7 + offset] - '0');
 137         stamp.tm_min =
 138                 (tm->data[8 + offset] - '0') * 10 + (tm->data[9 + offset] - '0');
 139         stamp.tm_sec = 0;
 140         stamp.tm_isdst = -1;
 141
 142         float time_left = difftime(timegm(&stamp), time(NULL));
 143         days_left = time_left / 86400;
 144         snprintf
 145                 (timestamp, TS_LENGTH, "%02d/%02d/%04d %02d:%02d %s",
 146                  stamp.tm_mon + 1,
 147                  stamp.tm_mday, stamp.tm_year + 1900, stamp.tm_hour, stamp.tm_min, stamp.tm_zone);
 148
 149         if (days_left > 0 && days_left <= days_till_exp) {
 150                 printf (_("WARNING - Certificate expires in %d day(s) (%s).\n"), days_left, timestamp);
 151                 return STATE_WARNING;
 152         } else if (time_left < 0) {
 153                 printf (_("CRITICAL - Certificate expired on %s.\n"), timestamp);
 154                 return STATE_CRITICAL;
 155         } else if (days_left == 0) {
 156                 printf (_("WARNING - Certificate expires today (%s).\n"), timestamp);
 157                 return STATE_WARNING;
 158         }
 159
 160         printf (_("OK - Certificate will expire on %s.\n"), timestamp);
 161         X509_free (certificate);
 162         return STATE_OK;
 163 #  else /* ifndef USE_OPENSSL */
 164         printf ("%s\n", _("WARNING - Plugin does not support checking certificates."));
 165         return STATE_WARNING;
 166 #  endif /* USE_OPENSSL */
 167 }
 168
 169 #endif /* HAVE_SSL */