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 int check_certificate (X509 **);
  57 #endif
  58
  59 enum {
  60         SMTP_PORT       = 25
  61 };
  62 const char *SMTP_EXPECT = "220";
  63 const char *SMTP_HELO = "HELO ";
  64 const char *SMTP_QUIT   = "QUIT\r\n";
  65 const char *SMTP_STARTTLS = "STARTTLS\r\n";
  66
  67 int process_arguments (int, char **);
  68 int validate_arguments (void);
  69 void print_help (void);
  70 void print_usage (void);
  71 int myrecv(void);
  72 int my_close(void);
  73
  74 #ifdef HAVE_REGEX_H
  75 #include <regex.h>
  76 char regex_expect[MAX_INPUT_BUFFER] = "";
  77 regex_t preg;
  78 regmatch_t pmatch[10];
  79 char timestamp[20] = "";
  80 char errbuf[MAX_INPUT_BUFFER];
  81 int cflags = REG_EXTENDED | REG_NOSUB | REG_NEWLINE;
  82 int eflags = 0;
  83 int errcode, excode;
  84 #endif
  85
  86 int server_port = SMTP_PORT;
  87 char *server_address = NULL;
  88 char *server_expect = NULL;
  89 int smtp_use_dummycmd = 0;
  90 char *mail_command = NULL;
  91 char *from_arg = NULL;
  92 int ncommands=0;
  93 int command_size=0;
  94 int nresponses=0;
  95 int response_size=0;
  96 char **commands = NULL;
  97 char **responses = NULL;
  98 int warning_time = 0;
  99 int check_warning_time = FALSE;
 100 int critical_time = 0;
 101 int check_critical_time = FALSE;
 102 int verbose = 0;
 103 int use_ssl = FALSE;
 104 int sd;
 105 char buffer[MAX_INPUT_BUFFER];
 106 enum {
 107   TCP_PROTOCOL = 1,
 108   UDP_PROTOCOL = 2,
 109   MAXBUF = 1024
 110 };
 111
 112 int
 113 main (int argc, char **argv)
 114 {
 115
 116         int n = 0;
 117         double elapsed_time;
 118         long microsec;
 119         int result = STATE_UNKNOWN;
 120         char *cmd_str = NULL;
 121         char *helocmd = NULL;
 122         struct timeval tv;
 123
 124         setlocale (LC_ALL, "");
 125         bindtextdomain (PACKAGE, LOCALEDIR);
 126         textdomain (PACKAGE);
 127
 128         if (process_arguments (argc, argv) == ERROR)
 129                 usage4 (_("Could not parse arguments"));
 130
 131         /* initialize the HELO command with the localhostname */
 132 #ifndef HOST_MAX_BYTES
 133 #define HOST_MAX_BYTES 255
 134 #endif
 135         helocmd = malloc (HOST_MAX_BYTES);
 136         gethostname(helocmd, HOST_MAX_BYTES);
 137         asprintf (&helocmd, "%s%s%s", SMTP_HELO, helocmd, "\r\n");
 138
 139         /* initialize the MAIL command with optional FROM command  */
 140         asprintf (&cmd_str, "%sFROM: %s%s", mail_command, from_arg, "\r\n");
 141
 142         if (verbose && smtp_use_dummycmd)
 143                 printf ("FROM CMD: %s", cmd_str);
 144
 145         /* initialize alarm signal handling */
 146         (void) signal (SIGALRM, socket_timeout_alarm_handler);
 147
 148         /* set socket timeout */
 149         (void) alarm (socket_timeout);
 150
 151         /* start timer */
 152         gettimeofday (&tv, NULL);
 153
 154         /* try to connect to the host at the given port number */
 155         result = my_tcp_connect (server_address, server_port, &sd);
 156
 157         if (result == STATE_OK) { /* we connected */
 158
 159                 /* watch for the SMTP connection string and */
 160                 /* return a WARNING status if we couldn't read any data */
 161                 if (recv (sd, buffer, MAX_INPUT_BUFFER - 1, 0) == -1) {
 162                         printf (_("recv() failed\n"));
 163                         result = STATE_WARNING;
 164                 }
 165                 else {
 166                         if (verbose)
 167                                 printf ("%s", buffer);
 168                         /* strip the buffer of carriage returns */
 169                         strip (buffer);
 170                         /* make sure we find the response we are looking for */
 171                         if (!strstr (buffer, server_expect)) {
 172                                 if (server_port == SMTP_PORT)
 173                                         printf (_("Invalid SMTP response received from host\n"));
 174                                 else
 175                                         printf (_("Invalid SMTP response received from host on port %d\n"),
 176                                                                         server_port);
 177                                 result = STATE_WARNING;
 178                         }
 179                 }
 180 #ifdef HAVE_SSL
 181                 if(use_ssl) {
 182                   /* send the STARTTLS command */
 183                   send(sd, SMTP_STARTTLS, strlen(SMTP_STARTTLS), 0);
 184
 185                   recv(sd,buffer, MAX_INPUT_BUFFER-1, 0); /* wait for it */
 186                   if (!strstr (buffer, server_expect)) {
 187                     printf (_("Server does not support STARTTLS\n"));
 188                     return STATE_UNKNOWN;
 189                   }
 190                   if(connect_STARTTLS() != OK) {
 191                     printf (_("CRITICAL - Cannot create SSL context.\n"));
 192                     return STATE_CRITICAL;
 193                   }
 194                   if ( check_cert ) {
 195                     if ((server_cert = SSL_get_peer_certificate (ssl)) != NULL) {
 196                       result = check_certificate (&server_cert);
 197                       X509_free(server_cert);
 198                     }
 199                     else {
 200                       printf (_("CRITICAL - Cannot retrieve server certificate.\n"));
 201                       result = STATE_CRITICAL;
 202
 203                     }
 204                     my_close();
 205                     return result;
 206                   }
 207                 }
 208 #endif
 209                 /* send the HELO command */
 210 #ifdef HAVE_SSL
 211                 if (use_ssl)
 212                   SSL_write(ssl, helocmd, strlen(helocmd));
 213                 else
 214 #endif
 215                 send(sd, helocmd, strlen(helocmd), 0);
 216
 217                 /* allow for response to helo command to reach us */
 218                 myrecv();
 219
 220                 /* sendmail will syslog a "NOQUEUE" error if session does not attempt
 221                  * to do something useful. This can be prevented by giving a command
 222                  * even if syntax is illegal (MAIL requires a FROM:<...> argument)
 223                  *
 224                  * According to rfc821 you can include a null reversepath in the from command
 225                  * - but a log message is generated on the smtp server.
 226                  *
 227                  * You can disable sending mail_command with '--nocommand'
 228                  * Use the -f option to provide a FROM address
 229                  */
 230                 if (smtp_use_dummycmd) {
 231 #ifdef HAVE_SSL
 232                   if (use_ssl)
 233                     SSL_write(ssl, cmd_str, strlen(cmd_str));
 234                   else
 235 #endif
 236                   send(sd, cmd_str, strlen(cmd_str), 0);
 237                   myrecv();
 238                   if (verbose)
 239                     printf("%s", buffer);
 240                 }
 241
 242                 while (n < ncommands) {
 243                         asprintf (&cmd_str, "%s%s", commands[n], "\r\n");
 244 #ifdef HAVE_SSL
 245                         if (use_ssl)
 246                           SSL_write(ssl,cmd_str, strlen(cmd_str));
 247                         else
 248 #endif
 249                         send(sd, cmd_str, strlen(cmd_str), 0);
 250                         myrecv();
 251                         if (verbose)
 252                                 printf("%s", buffer);
 253                         strip (buffer);
 254                         if (n < nresponses) {
 255 #ifdef HAVE_REGEX_H
 256                                 cflags |= REG_EXTENDED | REG_NOSUB | REG_NEWLINE;
 257                                 errcode = regcomp (&preg, responses[n], cflags);
 258                                 if (errcode != 0) {
 259                                         regerror (errcode, &preg, errbuf, MAX_INPUT_BUFFER);
 260                                         printf (_("Could Not Compile Regular Expression"));
 261                                         return ERROR;
 262                                 }
 263                                 excode = regexec (&preg, buffer, 10, pmatch, eflags);
 264                                 if (excode == 0) {
 265                                         result = STATE_OK;
 266                                 }
 267                                 else if (excode == REG_NOMATCH) {
 268                                         result = STATE_WARNING;
 269                                         printf (_("SMTP %s - Invalid response '%s' to command '%s'\n"), state_text (result), buffer, commands[n]);
 270                                 }
 271                                 else {
 272                                         regerror (excode, &preg, errbuf, MAX_INPUT_BUFFER);
 273                                         printf (_("Execute Error: %s\n"), errbuf);
 274                                         result = STATE_UNKNOWN;
 275                                 }
 276 #else
 277                                 if (strstr(buffer, responses[n])!=buffer) {
 278                                         result = STATE_WARNING;
 279                                         printf (_("SMTP %s - Invalid response '%s' to command '%s'\n"), state_text (result), buffer, commands[n]);
 280                                 }
 281 #endif
 282                         }
 283                         n++;
 284                 }
 285
 286                 /* tell the server we're done */
 287 #ifdef HAVE_SSL
 288                 if (use_ssl)
 289                   SSL_write(ssl,SMTP_QUIT, strlen (SMTP_QUIT));
 290                 else
 291 #endif
 292                 send (sd, SMTP_QUIT, strlen (SMTP_QUIT), 0);
 293
 294                 /* finally close the connection */
 295                 close (sd);
 296         }
 297
 298         /* reset the alarm */
 299         alarm (0);
 300
 301         microsec = deltime (tv);
 302         elapsed_time = (double)microsec / 1.0e6;
 303
 304         if (result == STATE_OK) {
 305                 if (check_critical_time && elapsed_time > (double) critical_time)
 306                         result = STATE_CRITICAL;
 307                 else if (check_warning_time && elapsed_time > (double) warning_time)
 308                         result = STATE_WARNING;
 309         }
 310
 311         printf (_("SMTP %s - %.3f sec. response time%s%s|%s\n"),
 312                 state_text (result), elapsed_time,
 313           verbose?", ":"", verbose?buffer:"",
 314                 fperfdata ("time", elapsed_time, "s",
 315                           (int)check_warning_time, warning_time,
 316                           (int)check_critical_time, critical_time,
 317                           TRUE, 0, FALSE, 0));
 318
 319         return result;
 320 }
 321
 322
 323
 324 /* process command-line arguments */
 325 int
 326 process_arguments (int argc, char **argv)
 327 {
 328         int c;
 329
 330         int option = 0;
 331         static struct option longopts[] = {
 332                 {"hostname", required_argument, 0, 'H'},
 333                 {"expect", required_argument, 0, 'e'},
 334                 {"critical", required_argument, 0, 'c'},
 335                 {"warning", required_argument, 0, 'w'},
 336                 {"timeout", required_argument, 0, 't'},
 337                 {"port", required_argument, 0, 'p'},
 338                 {"from", required_argument, 0, 'f'},
 339                 {"command", required_argument, 0, 'C'},
 340                 {"response", required_argument, 0, 'R'},
 341                 {"nocommand", required_argument, 0, 'n'},
 342                 {"verbose", no_argument, 0, 'v'},
 343                 {"version", no_argument, 0, 'V'},
 344                 {"use-ipv4", no_argument, 0, '4'},
 345                 {"use-ipv6", no_argument, 0, '6'},
 346                 {"help", no_argument, 0, 'h'},
 347                 {"starttls",no_argument,0,'S'},
 348                 {"certificate",required_argument,0,'D'},
 349                 {0, 0, 0, 0}
 350         };
 351
 352         if (argc < 2)
 353                 return ERROR;
 354
 355         for (c = 1; c < argc; c++) {
 356                 if (strcmp ("-to", argv[c]) == 0)
 357                         strcpy (argv[c], "-t");
 358                 else if (strcmp ("-wt", argv[c]) == 0)
 359                         strcpy (argv[c], "-w");
 360                 else if (strcmp ("-ct", argv[c]) == 0)
 361                         strcpy (argv[c], "-c");
 362         }
 363
 364         while (1) {
 365                 c = getopt_long (argc, argv, "+hVv46t:p:f:e:c:w:H:C:R:SD:",
 366                                  longopts, &option);
 367
 368                 if (c == -1 || c == EOF)
 369                         break;
 370
 371                 switch (c) {
 372                 case 'H':                                                                       /* hostname */
 373                         if (is_host (optarg)) {
 374                                 server_address = optarg;
 375                         }
 376                         else {
 377                                 usage2 (_("Invalid hostname/address"), optarg);
 378                         }
 379                         break;
 380                 case 'p':                                                                       /* port */
 381                         if (is_intpos (optarg))
 382                                 server_port = atoi (optarg);
 383                         else
 384                                 usage4 (_("Port must be a positive integer"));
 385                         break;
 386                 case 'f':                                                                       /* from argument */
 387                         from_arg = optarg;
 388                         smtp_use_dummycmd = 1;
 389                         break;
 390                 case 'e':                                                                       /* server expect string on 220  */
 391                         server_expect = optarg;
 392                         break;
 393                 case 'C':                                                                       /* commands  */
 394                         if (ncommands >= command_size) {
 395                                 commands = realloc (commands, command_size+8);
 396                                 if (commands == NULL)
 397                                         die (STATE_UNKNOWN,
 398                                              _("Could not realloc() units [%d]\n"), ncommands);
 399                         }
 400                         commands[ncommands] = optarg;
 401                         ncommands++;
 402                         break;
 403                 case 'R':                                                                       /* server responses */
 404                         if (nresponses >= response_size) {
 405                                 responses = realloc (responses, response_size+8);
 406                                 if (responses == NULL)
 407                                         die (STATE_UNKNOWN,
 408                                              _("Could not realloc() units [%d]\n"), nresponses);
 409                         }
 410                         responses[nresponses] = optarg;
 411                         nresponses++;
 412                         break;
 413                 case 'c':                                                                       /* critical time threshold */
 414                         if (is_intnonneg (optarg)) {
 415                                 critical_time = atoi (optarg);
 416                                 check_critical_time = TRUE;
 417                         }
 418                         else {
 419                                 usage4 (_("Critical time must be a positive integer"));
 420                         }
 421                         break;
 422                 case 'w':                                                                       /* warning time threshold */
 423                         if (is_intnonneg (optarg)) {
 424                                 warning_time = atoi (optarg);
 425                                 check_warning_time = TRUE;
 426                         }
 427                         else {
 428                                 usage4 (_("Warning time must be a positive integer"));
 429                         }
 430                         break;
 431                 case 'v':                                                                       /* verbose */
 432                         verbose++;
 433                         break;
 434                 case 't':                                                                       /* timeout */
 435                         if (is_intnonneg (optarg)) {
 436                                 socket_timeout = atoi (optarg);
 437                         }
 438                         else {
 439                                 usage4 (_("Timeout interval must be a positive integer"));
 440                         }
 441                         break;
 442                 case 'S':
 443                 /* starttls */
 444                         use_ssl = TRUE;
 445                         break;
 446                 case 'D':
 447                 /* Check SSL cert validity */
 448 #ifdef HAVE_SSL
 449                         if (!is_intnonneg (optarg))
 450                                 usage2 ("Invalid certificate expiration period",optarg);
 451                                 days_till_exp = atoi (optarg);
 452                                 check_cert = TRUE;
 453 #else
 454                                 usage (_("SSL support not available - install OpenSSL and recompile"));
 455 #endif
 456                         break;
 457                 case '4':
 458                         address_family = AF_INET;
 459                         break;
 460                 case '6':
 461 #ifdef USE_IPV6
 462                         address_family = AF_INET6;
 463 #else
 464                         usage4 (_("IPv6 support not available"));
 465 #endif
 466                         break;
 467                 case 'V':                                                                       /* version */
 468                         print_revision (progname, revision);
 469                         exit (STATE_OK);
 470                 case 'h':                                                                       /* help */
 471                         print_help ();
 472                         exit (STATE_OK);
 473                 case '?':                                                                       /* help */
 474                         usage2 (_("Unknown argument"), optarg);
 475                 }
 476         }
 477
 478         c = optind;
 479         if (server_address == NULL) {
 480                 if (argv[c]) {
 481                         if (is_host (argv[c]))
 482                                 server_address = argv[c];
 483                         else
 484                                 usage2 (_("Invalid hostname/address"), argv[c]);
 485                 }
 486                 else {
 487                         asprintf (&server_address, "127.0.0.1");
 488                 }
 489         }
 490
 491         if (server_expect == NULL)
 492                 server_expect = strdup (SMTP_EXPECT);
 493
 494         if (mail_command == NULL)
 495                 mail_command = strdup("MAIL ");
 496
 497         if (from_arg==NULL)
 498                 from_arg = strdup(" ");
 499
 500         return validate_arguments ();
 501 }
 502
 503
 504
 505 int
 506 validate_arguments (void)
 507 {
 508         return OK;
 509 }
 510
 511
 512
 513 void
 514 print_help (void)
 515 {
 516         char *myport;
 517         asprintf (&myport, "%d", SMTP_PORT);
 518
 519         print_revision (progname, revision);
 520
 521         printf ("Copyright (c) 1999-2001 Ethan Galstad <nagios@nagios.org>\n");
 522         printf (COPYRIGHT, copyright, email);
 523
 524         printf(_("This plugin will attempt to open an SMTP connection with the host.\n\n"));
 525
 526         print_usage ();
 527
 528         printf (_(UT_HELP_VRSN));
 529
 530         printf (_(UT_HOST_PORT), 'p', myport);
 531
 532         printf (_(UT_IPv46));
 533
 534         printf (_("\
 535  -e, --expect=STRING\n\
 536    String to expect in first line of server response (default: '%s')\n\
 537  -n, nocommand\n\
 538    Suppress SMTP command\n\
 539  -C, --command=STRING\n\
 540    SMTP command (may be used repeatedly)\n\
 541  -R, --command=STRING\n\
 542    Expected response to command (may be used repeatedly)\n\
 543  -f, --from=STRING\n\
 544    FROM-address to include in MAIL command, required by Exchange 2000\n"),
 545                 SMTP_EXPECT);
 546 #ifdef HAVE_SSL
 547         printf (_("\
 548  -D, --certificate=INTEGER\n\
 549     Minimum number of days a certificate has to be valid.\n\
 550  -S, --starttls\n\
 551     Use STARTTLS for the connection.\n"));
 552 #endif
 553
 554         printf (_(UT_WARN_CRIT));
 555
 556         printf (_(UT_TIMEOUT), DEFAULT_SOCKET_TIMEOUT);
 557
 558         printf (_(UT_VERBOSE));
 559
 560         printf(_("\n\
 561 Successul connects return STATE_OK, refusals and timeouts return\n\
 562 STATE_CRITICAL, other errors return STATE_UNKNOWN.  Successful\n\
 563 connects, but incorrect reponse messages from the host result in\n\
 564 STATE_WARNING return values.\n"));
 565
 566         printf (_(UT_SUPPORT));
 567 }
 568
 569
 570
 571 void
 572 print_usage (void)
 573 {
 574         printf ("\
 575 Usage: %s -H host [-p port] [-e expect] [-C command] [-f from addr]\n\
 576                   [-w warn] [-c crit] [-t timeout] [-S] [-D days] [-n] [-v] [-4|-6]\n", progname);
 577 }
 578
 579 #ifdef HAVE_SSL
 580 int
 581 connect_STARTTLS (void)
 582 {
 583   SSL_METHOD *meth;
 584
 585   /* Initialize SSL context */
 586   SSLeay_add_ssl_algorithms ();
 587   meth = SSLv2_client_method ();
 588   SSL_load_error_strings ();
 589   if ((ctx = SSL_CTX_new (meth)) == NULL)
 590     {
 591       printf(_("CRITICAL - Cannot create SSL context.\n"));
 592       return STATE_CRITICAL;
 593     }
 594   /* do the SSL handshake */
 595   if ((ssl = SSL_new (ctx)) != NULL)
 596     {
 597       SSL_set_fd (ssl, sd);
 598       /* original version checked for -1
 599          I look for success instead (1) */
 600       if (SSL_connect (ssl) == 1)
 601         return OK;
 602       ERR_print_errors_fp (stderr);
 603     }
 604   else
 605     {
 606       printf (_("CRITICAL - Cannot initiate SSL handshake.\n"));
 607     }
 608   /* this causes a seg faul
 609      not sure why, being sloppy
 610      and commenting it out */
 611   /*  SSL_free (ssl); */
 612   SSL_CTX_free(ctx);
 613   my_close();
 614
 615   return STATE_CRITICAL;
 616 }
 617
 618 int
 619 check_certificate (X509 ** certificate)
 620 {
 621   ASN1_STRING *tm;
 622   int offset;
 623   struct tm stamp;
 624   int days_left;
 625
 626   /* Retrieve timestamp of certificate */
 627   tm = X509_get_notAfter (*certificate);
 628
 629   /* Generate tm structure to process timestamp */
 630   if (tm->type == V_ASN1_UTCTIME) {
 631     if (tm->length < 10) {
 632       printf (_("CRITICAL - Wrong time format in certificate.\n"));
 633       return STATE_CRITICAL;
 634     }
 635     else {
 636       stamp.tm_year = (tm->data[0] - '0') * 10 + (tm->data[1] - '0');
 637       if (stamp.tm_year < 50)
 638         stamp.tm_year += 100;
 639       offset = 0;
 640     }
 641   }
 642   else {
 643     if (tm->length < 12) {
 644       printf (_("CRITICAL - Wrong time format in certificate.\n"));
 645       return STATE_CRITICAL;
 646     }
 647     else {
 648       stamp.tm_year =
 649         (tm->data[0] - '0') * 1000 + (tm->data[1] - '0') * 100 +
 650         (tm->data[2] - '0') * 10 + (tm->data[3] - '0');
 651       stamp.tm_year -= 1900;
 652       offset = 2;
 653     }
 654   }
 655   stamp.tm_mon =
 656     (tm->data[2 + offset] - '0') * 10 + (tm->data[3 + offset] - '0') - 1;
 657   stamp.tm_mday =
 658     (tm->data[4 + offset] - '0') * 10 + (tm->data[5 + offset] - '0');
 659   stamp.tm_hour =
 660     (tm->data[6 + offset] - '0') * 10 + (tm->data[7 + offset] - '0');
 661   stamp.tm_min =
 662     (tm->data[8 + offset] - '0') * 10 + (tm->data[9 + offset] - '0');
 663   stamp.tm_sec = 0;
 664   stamp.tm_isdst = -1;
 665
 666   days_left = (mktime (&stamp) - time (NULL)) / 86400;
 667   snprintf
 668     (timestamp, sizeof(timestamp), "%02d/%02d/%04d %02d:%02d",
 669      stamp.tm_mon + 1,
 670      stamp.tm_mday, stamp.tm_year + 1900, stamp.tm_hour, stamp.tm_min);
 671
 672   if (days_left > 0 && days_left <= days_till_exp) {
 673     printf ("Certificate expires in %d day(s) (%s).\n", days_left, timestamp);
 674     return STATE_WARNING;
 675   }
 676   if (days_left < 0) {
 677     printf ("Certificate expired on %s.\n", timestamp);
 678     return STATE_CRITICAL;
 679   }
 680
 681   if (days_left == 0) {
 682     printf ("Certificate expires today (%s).\n", timestamp);
 683     return STATE_WARNING;
 684   }
 685
 686   printf ("Certificate will expire on %s.\n", timestamp);
 687
 688   return STATE_OK;
 689 }
 690 #endif
 691
 692 int
 693 myrecv (void)
 694 {
 695   int i;
 696
 697 #ifdef HAVE_SSL
 698   if (use_ssl) {
 699     i = SSL_read (ssl, buffer, MAXBUF - 1);
 700   }
 701   else {
 702 #endif
 703     i = read (sd, buffer, MAXBUF - 1);
 704 #ifdef HAVE_SSL
 705   }
 706 #endif
 707   return i;
 708 }
 709
 710 int
 711 my_close (void)
 712 {
 713 #ifdef HAVE_SSL
 714   if (use_ssl == TRUE) {
 715     SSL_shutdown (ssl);
 716     SSL_free (ssl);
 717     SSL_CTX_free (ctx);
 718     return 0;
 719   }
 720   else {
 721 #endif
 722     return close(sd);
 723 #ifdef HAVE_SSL
 724   }
 725 #endif
 726 }