citadel/modules/crypto/serv_crypto.c

   1 // Copyright (c) 1987-2021 by the citadel.org team
   2 //
   3 // This program is open source software; you can redistribute it and/or modify
   4 // it under the terms of the GNU General Public License version 3.
   5 //
   6 // This program is distributed in the hope that it will be useful,
   7 // but WITHOUT ANY WARRANTY; without even the implied warranty of
   8 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   9 // GNU General Public License for more details.
  10
  11 #include <string.h>
  12 #include <unistd.h>
  13 #include <sys/stat.h>
  14 #include <sys/types.h>
  15 #include "sysdep.h"
  16
  17 #ifdef HAVE_OPENSSL
  18 #include <openssl/ssl.h>
  19 #include <openssl/err.h>
  20 #include <openssl/rand.h>
  21 #endif
  22
  23 #include <time.h>
  24
  25 #ifdef HAVE_PTHREAD_H
  26 #include <pthread.h>
  27 #endif
  28
  29 #ifdef HAVE_SYS_SELECT_H
  30 #include <sys/select.h>
  31 #endif
  32
  33 #include <stdio.h>
  34 #include <libcitadel.h>
  35 #include "server.h"
  36 #include "serv_crypto.h"
  37 #include "sysdep_decls.h"
  38 #include "citadel.h"
  39 #include "config.h"
  40 #include "ctdl_module.h"
  41
  42 #ifdef HAVE_OPENSSL
  43 SSL_CTX *ssl_ctx;                               // SSL context for all sessions
  44
  45
  46 void generate_key(char *keyfilename) {
  47         int ret = 0;
  48         RSA *rsa = NULL;
  49         BIGNUM *bne = NULL;
  50         int bits = 2048;
  51         unsigned long e = RSA_F4;
  52         FILE *fp;
  53
  54         if (access(keyfilename, R_OK) == 0) {   // we already have a key, so don't generate a new one
  55                 return;
  56         }
  57
  58         syslog(LOG_INFO, "crypto: generating RSA key pair");
  59
  60         // generate rsa key
  61         bne = BN_new();
  62         ret = BN_set_word(bne,e);
  63         if (ret != 1) {
  64                 goto free_all;
  65         }
  66
  67         rsa = RSA_new();
  68         ret = RSA_generate_key_ex(rsa, bits, bne, NULL);
  69         if (ret != 1) {
  70                 goto free_all;
  71         }
  72
  73         // write the key file
  74         fp = fopen(keyfilename, "w");
  75         if (fp != NULL) {
  76                 chmod(keyfilename, 0600);
  77                 if (PEM_write_RSAPrivateKey(fp, // the file
  78                                         rsa,    // the key
  79                                         NULL,   // no enc
  80                                         NULL,   // no passphrase
  81                                         0,      // no passphrase
  82                                         NULL,   // no callback
  83                                         NULL    // no callback
  84                 ) != 1) {
  85                         syslog(LOG_ERR, "crypto: cannot write key: %s", ERR_reason_error_string(ERR_get_error()));
  86                         unlink(keyfilename);
  87                 }
  88                 fclose(fp);
  89         }
  90
  91         // free the memory we used
  92 free_all:
  93         RSA_free(rsa);
  94         BN_free(bne);
  95 }
  96
  97
  98 // Set the private key and certificate chain for the global SSL Context.
  99 // This is called during initialization, and can be called again later if the certificate changes.
 100 void bind_to_key_and_certificate(void) {
 101
 102         syslog(LOG_DEBUG, "crypto: using certificate chain %s", file_crpt_file_cer);
 103         SSL_CTX_use_certificate_chain_file(ssl_ctx, file_crpt_file_cer);
 104
 105         syslog(LOG_DEBUG, "crypto: using private key %s", file_crpt_file_key);
 106         SSL_CTX_use_PrivateKey_file(ssl_ctx, file_crpt_file_key, SSL_FILETYPE_PEM);
 107         if ( !SSL_CTX_check_private_key(ssl_ctx) ) {
 108                 syslog(LOG_ERR, "crypto: cannot install certificate: %s", ERR_reason_error_string(ERR_get_error()));
 109         }
 110 }
 111
 112
 113 void init_ssl(void) {
 114         const SSL_METHOD *ssl_method;
 115         RSA *rsa = NULL;
 116         X509_REQ *req = NULL;
 117         X509 *cer = NULL;
 118         EVP_PKEY *pk = NULL;
 119         EVP_PKEY *req_pkey = NULL;
 120         X509_NAME *name = NULL;
 121         FILE *fp;
 122
 123         // Initialize SSL transport layer
 124         SSL_library_init();
 125         SSL_load_error_strings();
 126         ssl_method = SSLv23_server_method();
 127         if (!(ssl_ctx = SSL_CTX_new(ssl_method))) {
 128                 syslog(LOG_ERR, "crypto: SSL_CTX_new failed: %s", ERR_reason_error_string(ERR_get_error()));
 129                 return;
 130         }
 131         if (!(SSL_CTX_set_cipher_list(ssl_ctx, CIT_CIPHERS))) {
 132                 syslog(LOG_ERR, "crypto: No ciphers available");
 133                 SSL_CTX_free(ssl_ctx);
 134                 ssl_ctx = NULL;
 135                 return;
 136         }
 137
 138         mkdir(ctdl_key_dir, 0700);              // If the keys directory does not exist, create it
 139         generate_key(file_crpt_file_key);       // If a private key does not exist, create it
 140
 141         // If there is no certificate file on disk, we will be generating a self-signed certificate
 142         // in the next step.  Therefore, if we have neither a CSR nor a certificate, generate
 143         // the CSR in this step so that the next step may commence.
 144         if ( (access(file_crpt_file_cer, R_OK) != 0) && (access(file_crpt_file_csr, R_OK) != 0) ) {
 145                 syslog(LOG_INFO, "crypto: generating a generic certificate signing request.");
 146
 147                 // Read our key from the file.  No, we don't just keep this
 148                 // in memory from the above key-generation function, because
 149                 // there is the possibility that the key was already on disk
 150                 // and we didn't just generate it now.
 151                 fp = fopen(file_crpt_file_key, "r");
 152                 if (fp) {
 153                         rsa = PEM_read_RSAPrivateKey(fp, NULL, NULL, NULL);
 154                         fclose(fp);
 155                 }
 156
 157                 if (rsa) {
 158                         // Create a public key from the private key
 159                         if (pk=EVP_PKEY_new(), pk != NULL) {
 160                                 EVP_PKEY_assign_RSA(pk, rsa);
 161                                 if (req = X509_REQ_new(), req != NULL) {
 162
 163                                         // Set the public key
 164                                         X509_REQ_set_pubkey(req, pk);
 165                                         X509_REQ_set_version(req, 0L);
 166
 167                                         name = X509_REQ_get_subject_name(req);
 168
 169                                         // Tell it who we are
 170                                         X509_NAME_add_entry_by_txt(name, "C", MBSTRING_ASC, (unsigned const char *)"ZZ", -1, -1, 0);
 171                                         X509_NAME_add_entry_by_txt(name, "ST", MBSTRING_ASC, (unsigned const char *)"The World", -1, -1, 0);
 172                                         X509_NAME_add_entry_by_txt(name, "L", MBSTRING_ASC, (unsigned const char *)"My Location", -1, -1, 0);
 173                                         X509_NAME_add_entry_by_txt(name, "O", MBSTRING_ASC, (unsigned const char *)"Generic certificate", -1, -1, 0);
 174                                         X509_NAME_add_entry_by_txt(name, "OU", MBSTRING_ASC, (unsigned const char *)"Citadel server", -1, -1, 0);
 175                                         X509_NAME_add_entry_by_txt(name, "CN", MBSTRING_ASC, (unsigned const char *)"*", -1, -1, 0);
 176                                         X509_REQ_set_subject_name(req, name);
 177
 178                                         // Sign the CSR
 179                                         if (!X509_REQ_sign(req, pk, EVP_md5())) {
 180                                                 syslog(LOG_ERR, "crypto: X509_REQ_sign(): error");
 181                                         }
 182                                         else {
 183                                                 // Write it to disk
 184                                                 fp = fopen(file_crpt_file_csr, "w");
 185                                                 if (fp != NULL) {
 186                                                         chmod(file_crpt_file_csr, 0600);
 187                                                         PEM_write_X509_REQ(fp, req);
 188                                                         fclose(fp);
 189                                                 }
 190                                         }
 191
 192                                         X509_REQ_free(req);
 193                                 }
 194                         }
 195                         RSA_free(rsa);
 196                 }
 197                 else {
 198                         syslog(LOG_ERR, "crypto: unable to read private key.");
 199                 }
 200         }
 201
 202         // Generate a self-signed certificate if we don't have one.
 203         if (access(file_crpt_file_cer, R_OK) != 0) {
 204                 syslog(LOG_INFO, "crypto: generating a generic self-signed certificate.");
 205
 206                 // Same deal as before: always read the key from disk because
 207                 // it may or may not have just been generated.
 208                 fp = fopen(file_crpt_file_key, "r");
 209                 if (fp) {
 210                         rsa = PEM_read_RSAPrivateKey(fp, NULL, NULL, NULL);
 211                         fclose(fp);
 212                 }
 213
 214                 // This also holds true for the CSR.
 215                 req = NULL;
 216                 cer = NULL;
 217                 pk = NULL;
 218                 if (rsa) {
 219                         if (pk=EVP_PKEY_new(), pk != NULL) {
 220                                 EVP_PKEY_assign_RSA(pk, rsa);
 221                         }
 222
 223                         fp = fopen(file_crpt_file_csr, "r");
 224                         if (fp) {
 225                                 req = PEM_read_X509_REQ(fp, NULL, NULL, NULL);
 226                                 fclose(fp);
 227                         }
 228
 229                         if (req) {
 230                                 if (cer = X509_new(), cer != NULL) {
 231                                         ASN1_INTEGER_set(X509_get_serialNumber(cer), 0);
 232                                         X509_set_issuer_name(cer, X509_REQ_get_subject_name(req));
 233                                         X509_set_subject_name(cer, X509_REQ_get_subject_name(req));
 234                                         X509_gmtime_adj(X509_get_notBefore(cer),0);
 235                                         X509_gmtime_adj(X509_get_notAfter(cer),(long)60*60*24*SIGN_DAYS);
 236                                         req_pkey = X509_REQ_get_pubkey(req);
 237                                         X509_set_pubkey(cer, req_pkey);
 238                                         EVP_PKEY_free(req_pkey);
 239
 240                                         // Sign the cert
 241                                         if (!X509_sign(cer, pk, EVP_md5())) {
 242                                                 syslog(LOG_ERR, "crypto: X509_sign() error");
 243                                         }
 244                                         else {
 245                                                 // Write it to disk.
 246                                                 fp = fopen(file_crpt_file_cer, "w");
 247                                                 if (fp != NULL) {
 248                                                         chmod(file_crpt_file_cer, 0600);
 249                                                         PEM_write_X509(fp, cer);
 250                                                         fclose(fp);
 251                                                 }
 252                                         }
 253                                         X509_free(cer);
 254                                 }
 255                         }
 256
 257                         RSA_free(rsa);
 258                 }
 259         }
 260
 261         // Now try to bind to the key and certificate.
 262         bind_to_key_and_certificate();
 263
 264         // Finally let the server know we're here
 265         CtdlRegisterProtoHook(cmd_stls, "STLS", "Start SSL/TLS session");
 266         CtdlRegisterProtoHook(cmd_gtls, "GTLS", "Get SSL/TLS session status");
 267         CtdlRegisterSessionHook(endtls, EVT_STOP, PRIO_STOP + 10);
 268 }
 269
 270
 271 // client_write_ssl() Send binary data to the client encrypted.
 272 void client_write_ssl(const char *buf, int nbytes) {
 273         int retval;
 274         int nremain;
 275         char junk[1];
 276
 277         nremain = nbytes;
 278
 279         while (nremain > 0) {
 280                 if (SSL_want_write(CC->ssl)) {
 281                         if ((SSL_read(CC->ssl, junk, 0)) < 1) {
 282                                 syslog(LOG_DEBUG, "crypto: SSL_read in client_write: %s", ERR_reason_error_string(ERR_get_error()));
 283                         }
 284                 }
 285                 retval =
 286                     SSL_write(CC->ssl, &buf[nbytes - nremain], nremain);
 287                 if (retval < 1) {
 288                         long errval;
 289
 290                         errval = SSL_get_error(CC->ssl, retval);
 291                         if (errval == SSL_ERROR_WANT_READ ||
 292                             errval == SSL_ERROR_WANT_WRITE) {
 293                                 sleep(1);
 294                                 continue;
 295                         }
 296                         syslog(LOG_DEBUG, "crypto: SSL_write got error %ld, ret %d", errval, retval);
 297                         if (retval == -1) {
 298                                 syslog(LOG_DEBUG, "crypto: errno is %d", errno);
 299                         }
 300                         endtls();
 301                         client_write(&buf[nbytes - nremain], nremain);
 302                         return;
 303                 }
 304                 nremain -= retval;
 305         }
 306 }
 307
 308
 309 // read data from the encrypted layer.
 310 int client_read_sslbuffer(StrBuf *buf, int timeout) {
 311         char sbuf[16384];       // OpenSSL communicates in 16k blocks, so let's speak its native tongue.
 312         int rlen;
 313         char junk[1];
 314         SSL *pssl = CC->ssl;
 315
 316         if (pssl == NULL) return(-1);
 317
 318         while (1) {
 319                 if (SSL_want_read(pssl)) {
 320                         if ((SSL_write(pssl, junk, 0)) < 1) {
 321                                 syslog(LOG_DEBUG, "crypto: SSL_write in client_read");
 322                         }
 323                 }
 324                 rlen = SSL_read(pssl, sbuf, sizeof(sbuf));
 325                 if (rlen < 1) {
 326                         long errval;
 327
 328                         errval = SSL_get_error(pssl, rlen);
 329                         if (errval == SSL_ERROR_WANT_READ || errval == SSL_ERROR_WANT_WRITE) {
 330                                 sleep(1);
 331                                 continue;
 332                         }
 333                         syslog(LOG_DEBUG, "crypto: SSL_read got error %ld", errval);
 334                         endtls();
 335                         return (-1);
 336                 }
 337                 StrBufAppendBufPlain(buf, sbuf, rlen, 0);
 338                 return rlen;
 339         }
 340         return (0);
 341 }
 342
 343
 344 int client_readline_sslbuffer(StrBuf *Line, StrBuf *IOBuf, const char **Pos, int timeout) {
 345         const char *pos = NULL;
 346         const char *pLF;
 347         int len, rlen;
 348         int nSuccessLess = 0;
 349         const char *pch = NULL;
 350
 351         if ((Line == NULL) || (Pos == NULL) || (IOBuf == NULL)) {
 352                 if (Pos != NULL) {
 353                         *Pos = NULL;
 354                 }
 355                 return -1;
 356         }
 357
 358         pos = *Pos;
 359         if ((StrLength(IOBuf) > 0) && (pos != NULL) && (pos < ChrPtr(IOBuf) + StrLength(IOBuf))) {
 360                 pch = pos;
 361                 pch = strchr(pch, '\n');
 362
 363                 if (pch == NULL) {
 364                         StrBufAppendBufPlain(Line, pos, StrLength(IOBuf) - (pos - ChrPtr(IOBuf)), 0);
 365                         FlushStrBuf(IOBuf);
 366                         *Pos = NULL;
 367                 }
 368                 else {
 369                         int n = 0;
 370                         if ((pch > ChrPtr(IOBuf)) &&
 371                             (*(pch - 1) == '\r')) {
 372                                 n = 1;
 373                         }
 374                         StrBufAppendBufPlain(Line, pos,
 375                                              (pch - pos - n), 0);
 376
 377                         if (StrLength(IOBuf) <= (pch - ChrPtr(IOBuf) + 1)) {
 378                                 FlushStrBuf(IOBuf);
 379                                 *Pos = NULL;
 380                         }
 381                         else
 382                                 *Pos = pch + 1;
 383                         return StrLength(Line);
 384                 }
 385         }
 386
 387         pLF = NULL;
 388         while ((nSuccessLess < timeout) &&
 389                (pLF == NULL) &&
 390                (CC->ssl != NULL)) {
 391
 392                 rlen = client_read_sslbuffer(IOBuf, timeout);
 393                 if (rlen < 1) {
 394                         return -1;
 395                 }
 396                 else if (rlen > 0) {
 397                         pLF = strchr(ChrPtr(IOBuf), '\n');
 398                 }
 399         }
 400         *Pos = NULL;
 401         if (pLF != NULL) {
 402                 pos = ChrPtr(IOBuf);
 403                 len = pLF - pos;
 404                 if (len > 0 && (*(pLF - 1) == '\r') )
 405                         len --;
 406                 StrBufAppendBufPlain(Line, pos, len, 0);
 407                 if (pLF + 1 >= ChrPtr(IOBuf) + StrLength(IOBuf))
 408                 {
 409                         FlushStrBuf(IOBuf);
 410                 }
 411                 else
 412                         *Pos = pLF + 1;
 413                 return StrLength(Line);
 414         }
 415         return -1;
 416 }
 417
 418
 419 int client_read_sslblob(StrBuf *Target, long bytes, int timeout) {
 420         long baselen;
 421         long RemainRead;
 422         int retval = 0;
 423
 424         baselen = StrLength(Target);
 425
 426         if (StrLength(CC->RecvBuf.Buf) > 0) {
 427                 long RemainLen;
 428                 long TotalLen;
 429                 const char *pchs;
 430
 431                 if (CC->RecvBuf.ReadWritePointer == NULL) {
 432                         CC->RecvBuf.ReadWritePointer = ChrPtr(CC->RecvBuf.Buf);
 433                 }
 434                 pchs = ChrPtr(CC->RecvBuf.Buf);
 435                 TotalLen = StrLength(CC->RecvBuf.Buf);
 436                 RemainLen = TotalLen - (pchs - CC->RecvBuf.ReadWritePointer);
 437                 if (RemainLen > bytes) {
 438                         RemainLen = bytes;
 439                 }
 440                 if (RemainLen > 0) {
 441                         StrBufAppendBufPlain(Target, CC->RecvBuf.ReadWritePointer, RemainLen, 0);
 442                         CC->RecvBuf.ReadWritePointer += RemainLen;
 443                 }
 444                 if ((ChrPtr(CC->RecvBuf.Buf) + StrLength(CC->RecvBuf.Buf)) <= CC->RecvBuf.ReadWritePointer) {
 445                         CC->RecvBuf.ReadWritePointer = NULL;
 446                         FlushStrBuf(CC->RecvBuf.Buf);
 447                 }
 448         }
 449
 450         if (StrLength(Target) >= bytes + baselen) {
 451                 return 1;
 452         }
 453
 454         CC->RecvBuf.ReadWritePointer = NULL;
 455
 456         while ((StrLength(Target) < bytes + baselen) && (retval >= 0)) {
 457                 retval = client_read_sslbuffer(CC->RecvBuf.Buf, timeout);
 458                 if (retval >= 0) {
 459                         RemainRead = bytes - (StrLength (Target) - baselen);
 460                         if (RemainRead < StrLength(CC->RecvBuf.Buf)) {
 461                                 StrBufAppendBufPlain(
 462                                         Target,
 463                                         ChrPtr(CC->RecvBuf.Buf),
 464                                         RemainRead, 0);
 465                                 CC->RecvBuf.ReadWritePointer = ChrPtr(CC->RecvBuf.Buf) + RemainRead;
 466                                 break;
 467                         }
 468                         StrBufAppendBuf(Target, CC->RecvBuf.Buf, 0);    // todo: Buf > bytes?
 469                         FlushStrBuf(CC->RecvBuf.Buf);
 470                 }
 471                 else {
 472                         FlushStrBuf(CC->RecvBuf.Buf);
 473                         return -1;
 474
 475                 }
 476         }
 477         return 1;
 478 }
 479
 480
 481 // CtdlStartTLS() starts SSL/TLS encryption for the current session.  It
 482 // must be supplied with pre-generated strings for responses of "ok," "no
 483 // support for TLS," and "error" so that we can use this in any protocol.
 484 void CtdlStartTLS(char *ok_response, char *nosup_response, char *error_response) {
 485         int retval, bits, alg_bits;
 486
 487         if (CC->redirect_ssl) {
 488                 syslog(LOG_ERR, "crypto: attempt to begin SSL on an already encrypted connection");
 489                 if (error_response != NULL) {
 490                         cprintf("%s", error_response);
 491                 }
 492                 return;
 493         }
 494
 495         if (!ssl_ctx) {
 496                 syslog(LOG_ERR, "crypto: SSL failed: context has not been initialized");
 497                 if (nosup_response != NULL) {
 498                         cprintf("%s", nosup_response);
 499                 }
 500                 return;
 501         }
 502         if (!(CC->ssl = SSL_new(ssl_ctx))) {
 503                 syslog(LOG_ERR, "crypto: SSL_new failed: %s", ERR_reason_error_string(ERR_get_error()));
 504                 if (error_response != NULL) {
 505                         cprintf("%s", error_response);
 506                 }
 507                 return;
 508         }
 509         if (!(SSL_set_fd(CC->ssl, CC->client_socket))) {
 510                 syslog(LOG_ERR, "crypto: SSL_set_fd failed: %s", ERR_reason_error_string(ERR_get_error()));
 511                 SSL_free(CC->ssl);
 512                 CC->ssl = NULL;
 513                 if (error_response != NULL) {
 514                         cprintf("%s", error_response);
 515                 }
 516                 return;
 517         }
 518         if (ok_response != NULL) {
 519                 cprintf("%s", ok_response);
 520         }
 521         retval = SSL_accept(CC->ssl);
 522         if (retval < 1) {
 523                 // Can't notify the client of an error here; they will
 524                 // discover the problem at the SSL layer and should
 525                 // revert to unencrypted communications.
 526                 long errval;
 527                 char error_string[128];
 528
 529                 errval = SSL_get_error(CC->ssl, retval);
 530                 syslog(LOG_ERR, "crypto: SSL_accept failed: retval=%d, errval=%ld, err=%s",
 531                         retval,
 532                         errval,
 533                         ERR_error_string(errval, error_string)
 534                 );
 535                 SSL_free(CC->ssl);
 536                 CC->ssl = NULL;
 537                 return;
 538         }
 539         bits = SSL_CIPHER_get_bits(SSL_get_current_cipher(CC->ssl), &alg_bits);
 540         syslog(LOG_INFO, "crypto: SSL/TLS using %s on %s (%d of %d bits)",
 541                 SSL_CIPHER_get_name(SSL_get_current_cipher(CC->ssl)),
 542                 SSL_CIPHER_get_version(SSL_get_current_cipher(CC->ssl)),
 543                 bits, alg_bits
 544         );
 545         CC->redirect_ssl = 1;
 546 }
 547
 548
 549 // cmd_stls() starts SSL/TLS encryption for the current session
 550 void cmd_stls(char *params) {
 551         char ok_response[SIZ];
 552         char nosup_response[SIZ];
 553         char error_response[SIZ];
 554
 555         unbuffer_output();
 556
 557         sprintf(ok_response, "%d Begin TLS negotiation now\n", CIT_OK);
 558         sprintf(nosup_response, "%d TLS not supported here\n", ERROR + CMD_NOT_SUPPORTED);
 559         sprintf(error_response, "%d TLS negotiation error\n", ERROR + INTERNAL_ERROR);
 560
 561         CtdlStartTLS(ok_response, nosup_response, error_response);
 562 }
 563
 564
 565 // cmd_gtls() returns status info about the TLS connection
 566 void cmd_gtls(char *params) {
 567         int bits, alg_bits;
 568
 569         if (!CC->ssl || !CC->redirect_ssl) {
 570                 cprintf("%d Session is not encrypted.\n", ERROR);
 571                 return;
 572         }
 573         bits =
 574             SSL_CIPHER_get_bits(SSL_get_current_cipher(CC->ssl),
 575                                 &alg_bits);
 576         cprintf("%d %s|%s|%d|%d\n", CIT_OK,
 577                 SSL_CIPHER_get_version(SSL_get_current_cipher(CC->ssl)),
 578                 SSL_CIPHER_get_name(SSL_get_current_cipher(CC->ssl)),
 579                 alg_bits, bits);
 580 }
 581
 582
 583 // endtls() shuts down the TLS connection
 584 //
 585 // WARNING:  This may make your session vulnerable to a known plaintext
 586 // attack in the current implmentation.
 587 void endtls(void) {
 588         if (!CC->ssl) {
 589                 CC->redirect_ssl = 0;
 590                 return;
 591         }
 592
 593         syslog(LOG_INFO, "crypto: ending SSL/TLS");
 594         SSL_shutdown(CC->ssl);
 595         SSL_free(CC->ssl);
 596         CC->ssl = NULL;
 597         CC->redirect_ssl = 0;
 598 }
 599
 600 #endif  // HAVE_OPENSSL