plugins/check_smtp.c

   1 /******************************************************************************
   2
   3  This program is free software; you can redistribute it and/or modify
   4  it under the terms of the GNU General Public License as published by
   5  the Free Software Foundation; either version 2 of the License, or
   6  (at your option) any later version.
   7
   8  This program is distributed in the hope that it will be useful,
   9  but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  GNU General Public License for more details.
  12
  13  You should have received a copy of the GNU General Public License
  14  along with this program; if not, write to the Free Software
  15  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  16
  17  $Id$
  18
  19 ******************************************************************************/
  20
  21 const char *progname = "check_smtp";
  22 const char *revision = "$Revision$";
  23 const char *copyright = "2000-2004";
  24 const char *email = "nagiosplug-devel@lists.sourceforge.net";
  25
  26 #include "common.h"
  27 #include "netutils.h"
  28 #include "utils.h"
  29
  30 #ifdef HAVE_SSL_H
  31 #  include <rsa.h>
  32 #  include <crypto.h>
  33 #  include <x509.h>
  34 #  include <pem.h>
  35 #  include <ssl.h>
  36 #  include <err.h>
  37 #else
  38 #  ifdef HAVE_OPENSSL_SSL_H
  39 #    include <openssl/rsa.h>
  40 #    include <openssl/crypto.h>
  41 #    include <openssl/x509.h>
  42 #    include <openssl/pem.h>
  43 #    include <openssl/ssl.h>
  44 #    include <openssl/err.h>
  45 #  endif
  46 #endif
  47
  48 #ifdef HAVE_SSL
  49
  50 int check_cert = FALSE;
  51 int days_till_exp;
  52 SSL_CTX *ctx;
  53 SSL *ssl;
  54 X509 *server_cert;
  55 int connect_STARTTLS (void);
  56 #  ifdef USE_OPENSSL
  57 int check_certificate (X509 **);
  58 #  endif
  59 #endif
  60
  61 enum {
  62         SMTP_PORT       = 25
  63 };
  64 #define SMTP_EXPECT "220"
  65 #define SMTP_HELO "HELO "
  66 #define SMTP_EHLO "EHLO "
  67 #define SMTP_QUIT "QUIT\r\n"
  68 #define SMTP_STARTTLS "STARTTLS\r\n"
  69
  70 #ifndef HOST_MAX_BYTES
  71 #define HOST_MAX_BYTES 255
  72 #endif
  73
  74 #define EHLO_SUPPORTS_STARTTLS 1
  75
  76 int process_arguments (int, char **);
  77 int validate_arguments (void);
  78 void print_help (void);
  79 void print_usage (void);
  80 int myrecv(void);
  81 int my_close(void);
  82
  83 #ifdef HAVE_REGEX_H
  84 #include <regex.h>
  85 char regex_expect[MAX_INPUT_BUFFER] = "";
  86 regex_t preg;
  87 regmatch_t pmatch[10];
  88 char timestamp[20] = "";
  89 char errbuf[MAX_INPUT_BUFFER];
  90 int cflags = REG_EXTENDED | REG_NOSUB | REG_NEWLINE;
  91 int eflags = 0;
  92 int errcode, excode;
  93 #endif
  94
  95 int server_port = SMTP_PORT;
  96 char *server_address = NULL;
  97 char *server_expect = NULL;
  98 int smtp_use_dummycmd = 0;
  99 char *mail_command = NULL;
 100 char *from_arg = NULL;
 101 int ncommands=0;
 102 int command_size=0;
 103 int nresponses=0;
 104 int response_size=0;
 105 char **commands = NULL;
 106 char **responses = NULL;
 107 int warning_time = 0;
 108 int check_warning_time = FALSE;
 109 int critical_time = 0;
 110 int check_critical_time = FALSE;
 111 int verbose = 0;
 112 int use_ssl = FALSE;
 113 short use_ehlo = FALSE;
 114 short ssl_established = TRUE;
 115 char *localhostname = NULL;
 116 int sd;
 117 char buffer[MAX_INPUT_BUFFER];
 118 enum {
 119   TCP_PROTOCOL = 1,
 120   UDP_PROTOCOL = 2,
 121   MAXBUF = 1024
 122 };
 123
 124 int
 125 main (int argc, char **argv)
 126 {
 127         short supports_tls=FALSE;
 128         int n = 0;
 129         double elapsed_time;
 130         long microsec;
 131         int result = STATE_UNKNOWN;
 132         char *cmd_str = NULL;
 133         char *helocmd = NULL;
 134         struct timeval tv;
 135         struct hostent *hp;
 136
 137         setlocale (LC_ALL, "");
 138         bindtextdomain (PACKAGE, LOCALEDIR);
 139         textdomain (PACKAGE);
 140
 141         if (process_arguments (argc, argv) == ERROR)
 142                 usage4 (_("Could not parse arguments"));
 143
 144         /* initialize the HELO command with the localhostname */
 145         if(! localhostname){
 146                 localhostname = malloc (HOST_MAX_BYTES);
 147                 if(!localhostname){
 148                         printf(_("malloc() failed!\n"));
 149                         return STATE_CRITICAL;
 150                 }
 151                 if(gethostname(localhostname, HOST_MAX_BYTES)){
 152                         printf(_("gethostname() failed!\n"));
 153                         return STATE_CRITICAL;
 154                 }
 155                 hp = gethostbyname(localhostname);
 156                 if(!hp) helocmd = localhostname;
 157                 else helocmd = hp->h_name;
 158         } else {
 159                 helocmd = localhostname;
 160         }
 161         if(use_ehlo)
 162                 asprintf (&helocmd, "%s%s%s", SMTP_EHLO, helocmd, "\r\n");
 163         else
 164                 asprintf (&helocmd, "%s%s%s", SMTP_HELO, helocmd, "\r\n");
 165
 166         /* initialize the MAIL command with optional FROM command  */
 167         asprintf (&cmd_str, "%sFROM: %s%s", mail_command, from_arg, "\r\n");
 168
 169         if (verbose && smtp_use_dummycmd)
 170                 printf ("FROM CMD: %s", cmd_str);
 171
 172         /* initialize alarm signal handling */
 173         (void) signal (SIGALRM, socket_timeout_alarm_handler);
 174
 175         /* set socket timeout */
 176         (void) alarm (socket_timeout);
 177
 178         /* start timer */
 179         gettimeofday (&tv, NULL);
 180
 181         /* try to connect to the host at the given port number */
 182         result = my_tcp_connect (server_address, server_port, &sd);
 183
 184         if (result == STATE_OK) { /* we connected */
 185
 186                 /* watch for the SMTP connection string and */
 187                 /* return a WARNING status if we couldn't read any data */
 188                 if (recv (sd, buffer, MAX_INPUT_BUFFER - 1, 0) == -1) {
 189                         printf (_("recv() failed\n"));
 190                         result = STATE_WARNING;
 191                 }
 192                 else {
 193                         if (verbose)
 194                                 printf ("%s", buffer);
 195                         /* strip the buffer of carriage returns */
 196                         strip (buffer);
 197                         /* make sure we find the response we are looking for */
 198                         if (!strstr (buffer, server_expect)) {
 199                                 if (server_port == SMTP_PORT)
 200                                         printf (_("Invalid SMTP response received from host\n"));
 201                                 else
 202                                         printf (_("Invalid SMTP response received from host on port %d\n"),
 203                                                                         server_port);
 204                                 result = STATE_WARNING;
 205                         }
 206                 }
 207
 208                 /* send the HELO/EHLO command */
 209                 send(sd, helocmd, strlen(helocmd), 0);
 210
 211                 /* allow for response to helo command to reach us */
 212                 if(read (sd, buffer, MAXBUF - 1) < 0){
 213                         printf (_("recv() failed\n"));
 214                         return STATE_WARNING;
 215                 } else if(use_ehlo){
 216                         buffer[MAXBUF-1]='\0';
 217                         if(strstr(buffer, "250 STARTTLS") != NULL ||
 218                            strstr(buffer, "250-STARTTLS") != NULL){
 219                                 supports_tls=TRUE;
 220                         }
 221                 }
 222
 223                 if(use_ssl && ! supports_tls){
 224                         printf(_("WARNING - TLS not supported by server\n"));
 225                         send (sd, SMTP_QUIT, strlen (SMTP_QUIT), 0);
 226                         return STATE_WARNING;
 227                 }
 228
 229 #ifdef HAVE_SSL
 230                 if(use_ssl) {
 231                   /* send the STARTTLS command */
 232                   send(sd, SMTP_STARTTLS, strlen(SMTP_STARTTLS), 0);
 233
 234                   recv(sd,buffer, MAX_INPUT_BUFFER-1, 0); /* wait for it */
 235                   if (!strstr (buffer, server_expect)) {
 236                     printf (_("Server does not support STARTTLS\n"));
 237                     send (sd, SMTP_QUIT, strlen (SMTP_QUIT), 0);
 238                     return STATE_UNKNOWN;
 239                   }
 240                   if(connect_STARTTLS() != OK) {
 241                     printf (_("CRITICAL - Cannot create SSL context.\n"));
 242                     return STATE_CRITICAL;
 243                   } else {
 244                         ssl_established = TRUE;
 245                   }
 246 #  ifdef USE_OPENSSL
 247                   if ( check_cert ) {
 248                     if ((server_cert = SSL_get_peer_certificate (ssl)) != NULL) {
 249                       result = check_certificate (&server_cert);
 250                       X509_free(server_cert);
 251                     }
 252                     else {
 253                       printf (_("CRITICAL - Cannot retrieve server certificate.\n"));
 254                       result = STATE_CRITICAL;
 255
 256                     }
 257                     my_close();
 258                     return result;
 259                   }
 260 #  endif /* USE_OPENSSL */
 261                 }
 262 #endif
 263
 264                 /* sendmail will syslog a "NOQUEUE" error if session does not attempt
 265                  * to do something useful. This can be prevented by giving a command
 266                  * even if syntax is illegal (MAIL requires a FROM:<...> argument)
 267                  *
 268                  * According to rfc821 you can include a null reversepath in the from command
 269                  * - but a log message is generated on the smtp server.
 270                  *
 271                  * You can disable sending mail_command with '--nocommand'
 272                  * Use the -f option to provide a FROM address
 273                  */
 274                 if (smtp_use_dummycmd) {
 275 #ifdef HAVE_SSL
 276                   if (use_ssl)
 277                     SSL_write(ssl, cmd_str, strlen(cmd_str));
 278                   else
 279 #endif
 280                   send(sd, cmd_str, strlen(cmd_str), 0);
 281                   myrecv();
 282                   if (verbose)
 283                     printf("%s", buffer);
 284                 }
 285
 286                 while (n < ncommands) {
 287                         asprintf (&cmd_str, "%s%s", commands[n], "\r\n");
 288 #ifdef HAVE_SSL
 289                         if (use_ssl)
 290                           SSL_write(ssl,cmd_str, strlen(cmd_str));
 291                         else
 292 #endif
 293                         send(sd, cmd_str, strlen(cmd_str), 0);
 294                         myrecv();
 295                         if (verbose)
 296                                 printf("%s", buffer);
 297                         strip (buffer);
 298                         if (n < nresponses) {
 299 #ifdef HAVE_REGEX_H
 300                                 cflags |= REG_EXTENDED | REG_NOSUB | REG_NEWLINE;
 301                                 errcode = regcomp (&preg, responses[n], cflags);
 302                                 if (errcode != 0) {
 303                                         regerror (errcode, &preg, errbuf, MAX_INPUT_BUFFER);
 304                                         printf (_("Could Not Compile Regular Expression"));
 305                                         return ERROR;
 306                                 }
 307                                 excode = regexec (&preg, buffer, 10, pmatch, eflags);
 308                                 if (excode == 0) {
 309                                         result = STATE_OK;
 310                                 }
 311                                 else if (excode == REG_NOMATCH) {
 312                                         result = STATE_WARNING;
 313                                         printf (_("SMTP %s - Invalid response '%s' to command '%s'\n"), state_text (result), buffer, commands[n]);
 314                                 }
 315                                 else {
 316                                         regerror (excode, &preg, errbuf, MAX_INPUT_BUFFER);
 317                                         printf (_("Execute Error: %s\n"), errbuf);
 318                                         result = STATE_UNKNOWN;
 319                                 }
 320 #else
 321                                 if (strstr(buffer, responses[n])!=buffer) {
 322                                         result = STATE_WARNING;
 323                                         printf (_("SMTP %s - Invalid response '%s' to command '%s'\n"), state_text (result), buffer, commands[n]);
 324                                 }
 325 #endif
 326                         }
 327                         n++;
 328                 }
 329
 330                 /* tell the server we're done */
 331 #ifdef HAVE_SSL
 332                 if (use_ssl)
 333                   SSL_write(ssl,SMTP_QUIT, strlen (SMTP_QUIT));
 334                 else
 335 #endif
 336                 send (sd, SMTP_QUIT, strlen (SMTP_QUIT), 0);
 337
 338                 /* finally close the connection */
 339                 close (sd);
 340         }
 341
 342         /* reset the alarm */
 343         alarm (0);
 344
 345         microsec = deltime (tv);
 346         elapsed_time = (double)microsec / 1.0e6;
 347
 348         if (result == STATE_OK) {
 349                 if (check_critical_time && elapsed_time > (double) critical_time)
 350                         result = STATE_CRITICAL;
 351                 else if (check_warning_time && elapsed_time > (double) warning_time)
 352                         result = STATE_WARNING;
 353         }
 354
 355         printf (_("SMTP %s - %.3f sec. response time%s%s|%s\n"),
 356                 state_text (result), elapsed_time,
 357           verbose?", ":"", verbose?buffer:"",
 358                 fperfdata ("time", elapsed_time, "s",
 359                           (int)check_warning_time, warning_time,
 360                           (int)check_critical_time, critical_time,
 361                           TRUE, 0, FALSE, 0));
 362
 363         return result;
 364 }
 365
 366
 367
 368 /* process command-line arguments */
 369 int
 370 process_arguments (int argc, char **argv)
 371 {
 372         int c;
 373
 374         int option = 0;
 375         static struct option longopts[] = {
 376                 {"hostname", required_argument, 0, 'H'},
 377                 {"expect", required_argument, 0, 'e'},
 378                 {"critical", required_argument, 0, 'c'},
 379                 {"warning", required_argument, 0, 'w'},
 380                 {"timeout", required_argument, 0, 't'},
 381                 {"port", required_argument, 0, 'p'},
 382                 {"from", required_argument, 0, 'f'},
 383                 {"fqdn", required_argument, 0, 'F'},
 384                 {"command", required_argument, 0, 'C'},
 385                 {"response", required_argument, 0, 'R'},
 386                 {"nocommand", required_argument, 0, 'n'},
 387                 {"verbose", no_argument, 0, 'v'},
 388                 {"version", no_argument, 0, 'V'},
 389                 {"use-ipv4", no_argument, 0, '4'},
 390                 {"use-ipv6", no_argument, 0, '6'},
 391                 {"help", no_argument, 0, 'h'},
 392                 {"starttls",no_argument,0,'S'},
 393                 {"certificate",required_argument,0,'D'},
 394                 {0, 0, 0, 0}
 395         };
 396
 397         if (argc < 2)
 398                 return ERROR;
 399
 400         for (c = 1; c < argc; c++) {
 401                 if (strcmp ("-to", argv[c]) == 0)
 402                         strcpy (argv[c], "-t");
 403                 else if (strcmp ("-wt", argv[c]) == 0)
 404                         strcpy (argv[c], "-w");
 405                 else if (strcmp ("-ct", argv[c]) == 0)
 406                         strcpy (argv[c], "-c");
 407         }
 408
 409         while (1) {
 410                 c = getopt_long (argc, argv, "+hVv46t:p:f:e:c:w:H:C:R:SD:F:",
 411                                  longopts, &option);
 412
 413                 if (c == -1 || c == EOF)
 414                         break;
 415
 416                 switch (c) {
 417                 case 'H':                                                                       /* hostname */
 418                         if (is_host (optarg)) {
 419                                 server_address = optarg;
 420                         }
 421                         else {
 422                                 usage2 (_("Invalid hostname/address"), optarg);
 423                         }
 424                         break;
 425                 case 'p':                                                                       /* port */
 426                         if (is_intpos (optarg))
 427                                 server_port = atoi (optarg);
 428                         else
 429                                 usage4 (_("Port must be a positive integer"));
 430                         break;
 431                 case 'F':
 432                 /* localhostname */
 433                         localhostname = strdup(optarg);
 434                         break;
 435                 case 'f':                                                                       /* from argument */
 436                         from_arg = optarg;
 437                         smtp_use_dummycmd = 1;
 438                         break;
 439                 case 'e':                                                                       /* server expect string on 220  */
 440                         server_expect = optarg;
 441                         break;
 442                 case 'C':                                                                       /* commands  */
 443                         if (ncommands >= command_size) {
 444                                 commands = realloc (commands, command_size+8);
 445                                 if (commands == NULL)
 446                                         die (STATE_UNKNOWN,
 447                                              _("Could not realloc() units [%d]\n"), ncommands);
 448                         }
 449                         commands[ncommands] = optarg;
 450                         ncommands++;
 451                         break;
 452                 case 'R':                                                                       /* server responses */
 453                         if (nresponses >= response_size) {
 454                                 responses = realloc (responses, response_size+8);
 455                                 if (responses == NULL)
 456                                         die (STATE_UNKNOWN,
 457                                              _("Could not realloc() units [%d]\n"), nresponses);
 458                         }
 459                         responses[nresponses] = optarg;
 460                         nresponses++;
 461                         break;
 462                 case 'c':                                                                       /* critical time threshold */
 463                         if (is_intnonneg (optarg)) {
 464                                 critical_time = atoi (optarg);
 465                                 check_critical_time = TRUE;
 466                         }
 467                         else {
 468                                 usage4 (_("Critical time must be a positive integer"));
 469                         }
 470                         break;
 471                 case 'w':                                                                       /* warning time threshold */
 472                         if (is_intnonneg (optarg)) {
 473                                 warning_time = atoi (optarg);
 474                                 check_warning_time = TRUE;
 475                         }
 476                         else {
 477                                 usage4 (_("Warning time must be a positive integer"));
 478                         }
 479                         break;
 480                 case 'v':                                                                       /* verbose */
 481                         verbose++;
 482                         break;
 483                 case 't':                                                                       /* timeout */
 484                         if (is_intnonneg (optarg)) {
 485                                 socket_timeout = atoi (optarg);
 486                         }
 487                         else {
 488                                 usage4 (_("Timeout interval must be a positive integer"));
 489                         }
 490                         break;
 491                 case 'S':
 492                 /* starttls */
 493                         use_ssl = TRUE;
 494                         use_ehlo = TRUE;
 495                         break;
 496                 case 'D':
 497                 /* Check SSL cert validity */
 498 #ifdef USE_OPENSSL
 499                         if (!is_intnonneg (optarg))
 500                                 usage2 ("Invalid certificate expiration period",optarg);
 501                                 days_till_exp = atoi (optarg);
 502                                 check_cert = TRUE;
 503 #else
 504                                 usage (_("SSL support not available - install OpenSSL and recompile"));
 505 #endif
 506                         break;
 507                 case '4':
 508                         address_family = AF_INET;
 509                         break;
 510                 case '6':
 511 #ifdef USE_IPV6
 512                         address_family = AF_INET6;
 513 #else
 514                         usage4 (_("IPv6 support not available"));
 515 #endif
 516                         break;
 517                 case 'V':                                                                       /* version */
 518                         print_revision (progname, revision);
 519                         exit (STATE_OK);
 520                 case 'h':                                                                       /* help */
 521                         print_help ();
 522                         exit (STATE_OK);
 523                 case '?':                                                                       /* help */
 524                         usage2 (_("Unknown argument"), optarg);
 525                 }
 526         }
 527
 528         c = optind;
 529         if (server_address == NULL) {
 530                 if (argv[c]) {
 531                         if (is_host (argv[c]))
 532                                 server_address = argv[c];
 533                         else
 534                                 usage2 (_("Invalid hostname/address"), argv[c]);
 535                 }
 536                 else {
 537                         asprintf (&server_address, "127.0.0.1");
 538                 }
 539         }
 540
 541         if (server_expect == NULL)
 542                 server_expect = strdup (SMTP_EXPECT);
 543
 544         if (mail_command == NULL)
 545                 mail_command = strdup("MAIL ");
 546
 547         if (from_arg==NULL)
 548                 from_arg = strdup(" ");
 549
 550         return validate_arguments ();
 551 }
 552
 553
 554
 555 int
 556 validate_arguments (void)
 557 {
 558         return OK;
 559 }
 560
 561
 562
 563 void
 564 print_help (void)
 565 {
 566         char *myport;
 567         asprintf (&myport, "%d", SMTP_PORT);
 568
 569         print_revision (progname, revision);
 570
 571         printf ("Copyright (c) 1999-2001 Ethan Galstad <nagios@nagios.org>\n");
 572         printf (COPYRIGHT, copyright, email);
 573
 574         printf(_("This plugin will attempt to open an SMTP connection with the host.\n\n"));
 575
 576         print_usage ();
 577
 578         printf (_(UT_HELP_VRSN));
 579
 580         printf (_(UT_HOST_PORT), 'p', myport);
 581
 582         printf (_(UT_IPv46));
 583
 584         printf (_("\
 585  -e, --expect=STRING\n\
 586    String to expect in first line of server response (default: '%s')\n\
 587  -n, nocommand\n\
 588    Suppress SMTP command\n\
 589  -C, --command=STRING\n\
 590    SMTP command (may be used repeatedly)\n\
 591  -R, --command=STRING\n\
 592    Expected response to command (may be used repeatedly)\n\
 593  -f, --from=STRING\n\
 594    FROM-address to include in MAIL command, required by Exchange 2000\n"),
 595                 SMTP_EXPECT);
 596 #ifdef HAVE_SSL
 597         printf (_("\
 598  -D, --certificate=INTEGER\n\
 599     Minimum number of days a certificate has to be valid.\n\
 600  -S, --starttls\n\
 601     Use STARTTLS for the connection.\n"));
 602 #endif
 603
 604         printf (_(UT_WARN_CRIT));
 605
 606         printf (_(UT_TIMEOUT), DEFAULT_SOCKET_TIMEOUT);
 607
 608         printf (_(UT_VERBOSE));
 609
 610         printf(_("\n\
 611 Successul connects return STATE_OK, refusals and timeouts return\n\
 612 STATE_CRITICAL, other errors return STATE_UNKNOWN.  Successful\n\
 613 connects, but incorrect reponse messages from the host result in\n\
 614 STATE_WARNING return values.\n"));
 615
 616         printf (_(UT_SUPPORT));
 617 }
 618
 619
 620
 621 void
 622 print_usage (void)
 623 {
 624         printf ("\
 625 Usage: %s -H host [-p port] [-e expect] [-C command] [-f from addr]\n\
 626                   [-w warn] [-c crit] [-t timeout] [-S] [-D days] [-n] [-v] [-4|-6]\n", progname);
 627 }
 628
 629 #ifdef HAVE_SSL
 630 int
 631 connect_STARTTLS (void)
 632 {
 633   SSL_METHOD *meth;
 634
 635   /* Initialize SSL context */
 636   SSLeay_add_ssl_algorithms ();
 637   meth = SSLv23_client_method ();
 638   SSL_load_error_strings ();
 639   if ((ctx = SSL_CTX_new (meth)) == NULL)
 640     {
 641       printf(_("CRITICAL - Cannot create SSL context.\n"));
 642       return STATE_CRITICAL;
 643     }
 644   /* do the SSL handshake */
 645   if ((ssl = SSL_new (ctx)) != NULL)
 646     {
 647       SSL_set_fd (ssl, sd);
 648       /* original version checked for -1
 649          I look for success instead (1) */
 650       if (SSL_connect (ssl) == 1)
 651         return OK;
 652 #  ifdef USE_OPENSSL
 653       ERR_print_errors_fp (stderr);
 654 #  endif
 655     }
 656   else
 657     {
 658       printf (_("CRITICAL - Cannot initiate SSL handshake.\n"));
 659     }
 660   my_close();
 661
 662   return STATE_CRITICAL;
 663 }
 664
 665 #  ifdef USE_OPENSSL
 666 int
 667 check_certificate (X509 ** certificate)
 668 {
 669   ASN1_STRING *tm;
 670   int offset;
 671   struct tm stamp;
 672   int days_left;
 673
 674   /* Retrieve timestamp of certificate */
 675   tm = X509_get_notAfter (*certificate);
 676
 677   /* Generate tm structure to process timestamp */
 678   if (tm->type == V_ASN1_UTCTIME) {
 679     if (tm->length < 10) {
 680       printf (_("CRITICAL - Wrong time format in certificate.\n"));
 681       return STATE_CRITICAL;
 682     }
 683     else {
 684       stamp.tm_year = (tm->data[0] - '0') * 10 + (tm->data[1] - '0');
 685       if (stamp.tm_year < 50)
 686         stamp.tm_year += 100;
 687       offset = 0;
 688     }
 689   }
 690   else {
 691     if (tm->length < 12) {
 692       printf (_("CRITICAL - Wrong time format in certificate.\n"));
 693       return STATE_CRITICAL;
 694     }
 695     else {
 696       stamp.tm_year =
 697         (tm->data[0] - '0') * 1000 + (tm->data[1] - '0') * 100 +
 698         (tm->data[2] - '0') * 10 + (tm->data[3] - '0');
 699       stamp.tm_year -= 1900;
 700       offset = 2;
 701     }
 702   }
 703   stamp.tm_mon =
 704     (tm->data[2 + offset] - '0') * 10 + (tm->data[3 + offset] - '0') - 1;
 705   stamp.tm_mday =
 706     (tm->data[4 + offset] - '0') * 10 + (tm->data[5 + offset] - '0');
 707   stamp.tm_hour =
 708     (tm->data[6 + offset] - '0') * 10 + (tm->data[7 + offset] - '0');
 709   stamp.tm_min =
 710     (tm->data[8 + offset] - '0') * 10 + (tm->data[9 + offset] - '0');
 711   stamp.tm_sec = 0;
 712   stamp.tm_isdst = -1;
 713
 714   days_left = (mktime (&stamp) - time (NULL)) / 86400;
 715   snprintf
 716     (timestamp, sizeof(timestamp), "%02d/%02d/%04d %02d:%02d",
 717      stamp.tm_mon + 1,
 718      stamp.tm_mday, stamp.tm_year + 1900, stamp.tm_hour, stamp.tm_min);
 719
 720   if (days_left > 0 && days_left <= days_till_exp) {
 721     printf ("Certificate expires in %d day(s) (%s).\n", days_left, timestamp);
 722     return STATE_WARNING;
 723   }
 724   if (days_left < 0) {
 725     printf ("Certificate expired on %s.\n", timestamp);
 726     return STATE_CRITICAL;
 727   }
 728
 729   if (days_left == 0) {
 730     printf ("Certificate expires today (%s).\n", timestamp);
 731     return STATE_WARNING;
 732   }
 733
 734   printf ("Certificate will expire on %s.\n", timestamp);
 735
 736   return STATE_OK;
 737 }
 738 #  endif /* USE_OPENSSL */
 739 #endif
 740
 741 int
 742 myrecv (void)
 743 {
 744   int i;
 745
 746 #ifdef HAVE_SSL
 747   if (use_ssl) {
 748     i = SSL_read (ssl, buffer, MAXBUF - 1);
 749   }
 750   else {
 751 #endif
 752     i = read (sd, buffer, MAXBUF - 1);
 753 #ifdef HAVE_SSL
 754   }
 755 #endif
 756   return i;
 757 }
 758
 759 int
 760 my_close (void)
 761 {
 762 #ifdef HAVE_SSL
 763   if (use_ssl == TRUE && ssl_established == TRUE) {
 764     SSL_shutdown (ssl);
 765     SSL_free (ssl);
 766     SSL_CTX_free (ctx);
 767     return 0;
 768   }
 769   else {
 770 #endif
 771     return close(sd);
 772 #ifdef HAVE_SSL
 773   }
 774 #endif
 775 }