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/*****************************************************************************
*
* Nagios plugins SSL utilities
*
* License: GPL
* Copyright (c) 2005-2010 Nagios Plugins Development Team
*
* Description:
*
* This file contains common functions for plugins that require SSL.
*
*
* 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/>.
*
*
*****************************************************************************/
#define MAX_CN_LENGTH 256
#include "common.h"
#include "netutils.h"
#ifdef HAVE_SSL
static SSL_CTX *c=NULL;
static SSL *s=NULL;
static int initialized=0;
int np_net_ssl_init(int sd) {
return np_net_ssl_init_with_hostname(sd, NULL);
}
int np_net_ssl_init_with_hostname(int sd, char *host_name) {
return np_net_ssl_init_with_hostname_and_version(sd, host_name, 0);
}
int np_net_ssl_init_with_hostname_and_version(int sd, char *host_name, int version) {
return np_net_ssl_init_with_hostname_version_and_cert(sd, host_name, version, NULL, NULL);
}
int np_net_ssl_init_with_hostname_version_and_cert(int sd, char *host_name, int version, char *cert, char *privkey) {
SSL_METHOD *method = NULL;
switch (version) {
case 0: /* Deafult to auto negotiation */
method = SSLv23_client_method();
break;
case 1: /* TLSv1 protocol */
method = TLSv1_client_method();
break;
case 2: /* SSLv2 protocol */
#if defined(USE_GNUTLS) || defined(OPENSSL_NO_SSL2)
printf(("%s\n", _("CRITICAL - SSL protocol version 2 is not supported by your SSL library.")));
return STATE_CRITICAL;
#else
method = SSLv2_client_method();
#endif
break;
case 3: /* SSLv3 protocol */
method = SSLv3_client_method();
break;
default: /* Unsupported */
printf("%s\n", _("CRITICAL - Unsupported SSL protocol version."));
return STATE_CRITICAL;
}
if (!initialized) {
/* Initialize SSL context */
SSLeay_add_ssl_algorithms();
SSL_load_error_strings();
OpenSSL_add_all_algorithms();
initialized = 1;
}
if ((c = SSL_CTX_new(method)) == NULL) {
printf("%s\n", _("CRITICAL - Cannot create SSL context."));
return STATE_CRITICAL;
}
if (cert && privkey) {
SSL_CTX_use_certificate_file(c, cert, SSL_FILETYPE_PEM);
SSL_CTX_use_PrivateKey_file(c, privkey, SSL_FILETYPE_PEM);
if (!SSL_CTX_check_private_key(c)) {
printf ("%s\n", _("CRITICAL - Private key does not seem to match certificate!\n"));
return STATE_CRITICAL;
}
}
#ifdef SSL_OP_NO_TICKET
SSL_CTX_set_options(c, SSL_OP_NO_TICKET);
#endif
SSL_CTX_set_mode(c, SSL_MODE_AUTO_RETRY);
if ((s = SSL_new(c)) != NULL) {
#ifdef SSL_set_tlsext_host_name
if (host_name != NULL)
SSL_set_tlsext_host_name(s, host_name);
#endif
SSL_set_fd(s, sd);
if (SSL_connect(s) == 1) {
return OK;
} else {
printf("%s\n", _("CRITICAL - Cannot make SSL connection."));
# ifdef USE_OPENSSL /* XXX look into ERR_error_string */
ERR_print_errors_fp(stdout);
# endif /* USE_OPENSSL */
}
} else {
printf("%s\n", _("CRITICAL - Cannot initiate SSL handshake."));
}
return STATE_CRITICAL;
}
void np_net_ssl_cleanup() {
if (s) {
#ifdef SSL_set_tlsext_host_name
SSL_set_tlsext_host_name(s, NULL);
#endif
SSL_shutdown(s);
SSL_free(s);
if (c) {
SSL_CTX_free(c);
c=NULL;
}
s=NULL;
}
}
int np_net_ssl_write(const void *buf, int num) {
return SSL_write(s, buf, num);
}
int np_net_ssl_read(void *buf, int num) {
return SSL_read(s, buf, num);
}
int np_net_ssl_check_cert(int days_till_exp_warn, int days_till_exp_crit){
# ifdef USE_OPENSSL
X509 *certificate=NULL;
X509_NAME *subj=NULL;
char cn[MAX_CN_LENGTH]= "";
int cnlen =-1;
int status=STATE_UNKNOWN;
ASN1_STRING *tm;
int offset;
struct tm stamp;
float time_left;
int days_left;
char timestamp[17] = "";
certificate=SSL_get_peer_certificate(s);
if (!certificate) {
printf("%s\n",_("CRITICAL - Cannot retrieve server certificate."));
return STATE_CRITICAL;
}
/* Extract CN from certificate subject */
subj=X509_get_subject_name(certificate);
if (!subj) {
printf("%s\n",_("CRITICAL - Cannot retrieve certificate subject."));
return STATE_CRITICAL;
}
cnlen = X509_NAME_get_text_by_NID(subj, NID_commonName, cn, sizeof(cn));
if (cnlen == -1)
strcpy(cn, _("Unknown CN"));
/* Retrieve timestamp of certificate */
tm = X509_get_notAfter(certificate);
/* Generate tm structure to process timestamp */
if (tm->type == V_ASN1_UTCTIME) {
if (tm->length < 10) {
printf("%s\n", _("CRITICAL - Wrong time format in certificate."));
return STATE_CRITICAL;
} else {
stamp.tm_year = (tm->data[0] - '0') * 10 + (tm->data[1] - '0');
if (stamp.tm_year < 50)
stamp.tm_year += 100;
offset = 0;
}
} else {
if (tm->length < 12) {
printf("%s\n", _("CRITICAL - Wrong time format in certificate."));
return STATE_CRITICAL;
} else {
stamp.tm_year =
(tm->data[0] - '0') * 1000 + (tm->data[1] - '0') * 100 +
(tm->data[2] - '0') * 10 + (tm->data[3] - '0');
stamp.tm_year -= 1900;
offset = 2;
}
}
stamp.tm_mon =
(tm->data[2 + offset] - '0') * 10 + (tm->data[3 + offset] - '0') - 1;
stamp.tm_mday =
(tm->data[4 + offset] - '0') * 10 + (tm->data[5 + offset] - '0');
stamp.tm_hour =
(tm->data[6 + offset] - '0') * 10 + (tm->data[7 + offset] - '0');
stamp.tm_min =
(tm->data[8 + offset] - '0') * 10 + (tm->data[9 + offset] - '0');
stamp.tm_sec = 0;
stamp.tm_isdst = -1;
time_left = difftime(timegm(&stamp), time(NULL));
days_left = time_left / 86400;
snprintf
(timestamp, 17, "%02d/%02d/%04d %02d:%02d",
stamp.tm_mon + 1,
stamp.tm_mday, stamp.tm_year + 1900, stamp.tm_hour, stamp.tm_min);
if (days_left > 0 && days_left <= days_till_exp_warn) {
printf (_("%s - Certificate '%s' expires in %d day(s) (%s).\n"), (days_left>days_till_exp_crit)?"WARNING":"CRITICAL", cn, days_left, timestamp);
if (days_left > days_till_exp_crit)
return STATE_WARNING;
else
return STATE_CRITICAL;
} else if (time_left < 0) {
printf(_("CRITICAL - Certificate '%s' expired on %s.\n"), cn, timestamp);
status=STATE_CRITICAL;
} else if (days_left == 0) {
printf (_("%s - Certificate '%s' expires today (%s).\n"), (days_left>days_till_exp_crit)?"WARNING":"CRITICAL", cn, timestamp);
if (days_left > days_till_exp_crit)
return STATE_WARNING;
else
return STATE_CRITICAL;
} else {
printf(_("OK - Certificate '%s' will expire on %s.\n"), cn, timestamp);
status=STATE_OK;
}
X509_free(certificate);
return status;
# else /* ifndef USE_OPENSSL */
printf("%s\n", _("WARNING - Plugin does not support checking certificates."));
return STATE_WARNING;
# endif /* USE_OPENSSL */
}
#endif /* HAVE_SSL */
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