citadel/modules/crypto/serv_crypto.c

   1 /*
   2  * Copyright (c) 1987-2018 by the citadel.org team
   3  *
   4  * This program is open source software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 3.
   6  *
   7  * This program is distributed in the hope that it will be useful,
   8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10  * GNU General Public License for more details.
  11  */
  12
  13 #include <string.h>
  14 #include <unistd.h>
  15 #include <sys/stat.h>
  16 #include <sys/types.h>
  17 #include "sysdep.h"
  18
  19 #ifdef HAVE_OPENSSL
  20 #include <openssl/ssl.h>
  21 #include <openssl/err.h>
  22 #include <openssl/rand.h>
  23 #endif
  24
  25 #include <time.h>
  26
  27 #ifdef HAVE_PTHREAD_H
  28 #include <pthread.h>
  29 #endif
  30
  31 #ifdef HAVE_SYS_SELECT_H
  32 #include <sys/select.h>
  33 #endif
  34
  35 #include <stdio.h>
  36 #include <libcitadel.h>
  37 #include "server.h"
  38 #include "serv_crypto.h"
  39 #include "sysdep_decls.h"
  40 #include "citadel.h"
  41 #include "config.h"
  42
  43
  44 #include "ctdl_module.h"
  45
  46 #ifdef HAVE_OPENSSL
  47 SSL_CTX *ssl_ctx;               /* SSL context */
  48 pthread_mutex_t **SSLCritters;  /* Things needing locking */
  49
  50 static unsigned long id_callback(void)
  51 {
  52         return (unsigned long) pthread_self();
  53 }
  54
  55 void destruct_ssl(void)
  56 {
  57         int a;
  58         for (a = 0; a < CRYPTO_num_locks(); a++)
  59                 free(SSLCritters[a]);
  60         free (SSLCritters);
  61 }
  62
  63
  64 void generate_key(char *keyfilename)
  65 {
  66         int ret = 0;
  67         RSA *rsa = NULL;
  68         BIGNUM *bne = NULL;
  69         int bits = 2048;
  70         unsigned long e = RSA_F4;
  71         FILE *fp;
  72
  73         if (access(keyfilename, R_OK) == 0) {
  74                 return;
  75         }
  76
  77         syslog(LOG_INFO, "crypto: generating RSA key pair");
  78
  79         // generate rsa key
  80         bne = BN_new();
  81         ret = BN_set_word(bne,e);
  82         if (ret != 1) {
  83                 goto free_all;
  84         }
  85
  86         rsa = RSA_new();
  87         ret = RSA_generate_key_ex(rsa, bits, bne, NULL);
  88         if (ret != 1) {
  89                 goto free_all;
  90         }
  91
  92         // write the key file
  93         fp = fopen(keyfilename, "w");
  94         if (fp != NULL) {
  95                 chmod(keyfilename, 0600);
  96                 if (PEM_write_RSAPrivateKey(fp, /* the file */
  97                                         rsa,    /* the key */
  98                                         NULL,   /* no enc */
  99                                         NULL,   /* no passphr */
 100                                         0,      /* no passphr */
 101                                         NULL,   /* no callbk */
 102                                         NULL    /* no callbk */
 103                 ) != 1) {
 104                         syslog(LOG_ERR, "crypto: cannot write key: %s", ERR_reason_error_string(ERR_get_error()));
 105                         unlink(keyfilename);
 106                 }
 107                 fclose(fp);
 108         }
 109
 110     // 4. free
 111 free_all:
 112     RSA_free(rsa);
 113     BN_free(bne);
 114 }
 115
 116
 117 void init_ssl(void)
 118 {
 119         const SSL_METHOD *ssl_method;
 120         RSA *rsa = NULL;
 121         X509_REQ *req = NULL;
 122         X509 *cer = NULL;
 123         EVP_PKEY *pk = NULL;
 124         EVP_PKEY *req_pkey = NULL;
 125         X509_NAME *name = NULL;
 126         FILE *fp;
 127
 128         SSLCritters = malloc(CRYPTO_num_locks() * sizeof(pthread_mutex_t *));
 129         if (!SSLCritters) {
 130                 syslog(LOG_ERR, "crypto: can't allocate memory!");
 131                 exit(CTDLEXIT_CRYPTO);
 132         } else {
 133                 int a;
 134
 135                 for (a = 0; a < CRYPTO_num_locks(); a++) {
 136                         SSLCritters[a] = malloc(sizeof(pthread_mutex_t));
 137                         if (!SSLCritters[a]) {
 138                                 syslog(LOG_ERR, "crypto: can't allocate memory!!");
 139                                 exit(CTDLEXIT_CRYPTO);
 140                         }
 141                         pthread_mutex_init(SSLCritters[a], NULL);
 142                 }
 143         }
 144
 145         /*
 146          * Initialize SSL transport layer
 147          */
 148         SSL_library_init();
 149         SSL_load_error_strings();
 150         ssl_method = SSLv23_server_method();
 151         if (!(ssl_ctx = SSL_CTX_new(ssl_method))) {
 152                 syslog(LOG_ERR, "crypto: SSL_CTX_new failed: %s", ERR_reason_error_string(ERR_get_error()));
 153                 return;
 154         }
 155         if (!(SSL_CTX_set_cipher_list(ssl_ctx, CIT_CIPHERS))) {
 156                 syslog(LOG_ERR, "crypto: No ciphers available");
 157                 SSL_CTX_free(ssl_ctx);
 158                 ssl_ctx = NULL;
 159                 return;
 160         }
 161
 162         CRYPTO_set_locking_callback(ssl_lock);
 163         CRYPTO_set_id_callback(id_callback);
 164
 165         mkdir(ctdl_key_dir, 0700);              // If the keys directory does not exist, create it
 166         generate_key(file_crpt_file_key);       // If a private key does not exist, create it
 167
 168         /*
 169          * If there is no certificate file on disk, we will be generating a self-signed certificate
 170          * in the next step.  Therefore, if we have neither a CSR nor a certificate, generate
 171          * the CSR in this step so that the next step may commence.
 172          */
 173         if ( (access(file_crpt_file_cer, R_OK) != 0) && (access(file_crpt_file_csr, R_OK) != 0) ) {
 174                 syslog(LOG_INFO, "crypto: generating a generic certificate signing request.");
 175
 176                 /*
 177                  * Read our key from the file.  No, we don't just keep this
 178                  * in memory from the above key-generation function, because
 179                  * there is the possibility that the key was already on disk
 180                  * and we didn't just generate it now.
 181                  */
 182                 fp = fopen(file_crpt_file_key, "r");
 183                 if (fp) {
 184                         rsa = PEM_read_RSAPrivateKey(fp, NULL, NULL, NULL);
 185                         fclose(fp);
 186                 }
 187
 188                 if (rsa) {
 189
 190                         /* Create a public key from the private key */
 191                         if (pk=EVP_PKEY_new(), pk != NULL) {
 192                                 EVP_PKEY_assign_RSA(pk, rsa);
 193                                 if (req = X509_REQ_new(), req != NULL) {
 194
 195                                         /* Set the public key */
 196                                         X509_REQ_set_pubkey(req, pk);
 197                                         X509_REQ_set_version(req, 0L);
 198
 199                                         name = X509_REQ_get_subject_name(req);
 200
 201                                         /* Tell it who we are */
 202                                         X509_NAME_add_entry_by_txt(name, "C", MBSTRING_ASC, (unsigned const char *)"ZZ", -1, -1, 0);
 203                                         X509_NAME_add_entry_by_txt(name, "ST", MBSTRING_ASC, (unsigned const char *)"The World", -1, -1, 0);
 204                                         X509_NAME_add_entry_by_txt(name, "L", MBSTRING_ASC, (unsigned const char *)"My Location", -1, -1, 0);
 205                                         X509_NAME_add_entry_by_txt(name, "O", MBSTRING_ASC, (unsigned const char *)"Generic certificate", -1, -1, 0);
 206                                         X509_NAME_add_entry_by_txt(name, "OU", MBSTRING_ASC, (unsigned const char *)"Citadel server", -1, -1, 0);
 207                                         X509_NAME_add_entry_by_txt(name, "CN", MBSTRING_ASC, (unsigned const char *)"*", -1, -1, 0);
 208                                         X509_REQ_set_subject_name(req, name);
 209
 210                                         /* Sign the CSR */
 211                                         if (!X509_REQ_sign(req, pk, EVP_md5())) {
 212                                                 syslog(LOG_ERR, "crypto: X509_REQ_sign(): error");
 213                                         }
 214                                         else {
 215                                                 /* Write it to disk. */
 216                                                 fp = fopen(file_crpt_file_csr, "w");
 217                                                 if (fp != NULL) {
 218                                                         chmod(file_crpt_file_csr, 0600);
 219                                                         PEM_write_X509_REQ(fp, req);
 220                                                         fclose(fp);
 221                                                 }
 222                                         }
 223
 224                                         X509_REQ_free(req);
 225                                 }
 226                         }
 227
 228                         RSA_free(rsa);
 229                 }
 230
 231                 else {
 232                         syslog(LOG_ERR, "crypto: unable to read private key.");
 233                 }
 234         }
 235
 236
 237         /*
 238          * Generate a self-signed certificate if we don't have one.
 239          */
 240         if (access(file_crpt_file_cer, R_OK) != 0) {
 241                 syslog(LOG_INFO, "crypto: generating a generic self-signed certificate.");
 242
 243                 /* Same deal as before: always read the key from disk because
 244                  * it may or may not have just been generated.
 245                  */
 246                 fp = fopen(file_crpt_file_key, "r");
 247                 if (fp) {
 248                         rsa = PEM_read_RSAPrivateKey(fp, NULL, NULL, NULL);
 249                         fclose(fp);
 250                 }
 251
 252                 /* This also holds true for the CSR. */
 253                 req = NULL;
 254                 cer = NULL;
 255                 pk = NULL;
 256                 if (rsa) {
 257                         if (pk=EVP_PKEY_new(), pk != NULL) {
 258                                 EVP_PKEY_assign_RSA(pk, rsa);
 259                         }
 260
 261                         fp = fopen(file_crpt_file_csr, "r");
 262                         if (fp) {
 263                                 req = PEM_read_X509_REQ(fp, NULL, NULL, NULL);
 264                                 fclose(fp);
 265                         }
 266
 267                         if (req) {
 268                                 if (cer = X509_new(), cer != NULL) {
 269                                         ASN1_INTEGER_set(X509_get_serialNumber(cer), 0);
 270                                         X509_set_issuer_name(cer, X509_REQ_get_subject_name(req));
 271                                         X509_set_subject_name(cer, X509_REQ_get_subject_name(req));
 272                                         X509_gmtime_adj(X509_get_notBefore(cer),0);
 273                                         X509_gmtime_adj(X509_get_notAfter(cer),(long)60*60*24*SIGN_DAYS);
 274                                         req_pkey = X509_REQ_get_pubkey(req);
 275                                         X509_set_pubkey(cer, req_pkey);
 276                                         EVP_PKEY_free(req_pkey);
 277
 278                                         /* Sign the cert */
 279                                         if (!X509_sign(cer, pk, EVP_md5())) {
 280                                                 syslog(LOG_ERR, "crypto: X509_sign() error");
 281                                         }
 282                                         else {
 283                                                 /* Write it to disk. */
 284                                                 fp = fopen(file_crpt_file_cer, "w");
 285                                                 if (fp != NULL) {
 286                                                         chmod(file_crpt_file_cer, 0600);
 287                                                         PEM_write_X509(fp, cer);
 288                                                         fclose(fp);
 289                                                 }
 290                                         }
 291                                         X509_free(cer);
 292                                 }
 293                         }
 294
 295                         RSA_free(rsa);
 296                 }
 297         }
 298
 299
 300         /*
 301          * Now try to bind to the key and certificate.
 302          */
 303         SSL_CTX_use_certificate_chain_file(ssl_ctx, file_crpt_file_cer);
 304         SSL_CTX_use_PrivateKey_file(ssl_ctx, file_crpt_file_key, SSL_FILETYPE_PEM);
 305         if ( !SSL_CTX_check_private_key(ssl_ctx) ) {
 306                 syslog(LOG_ERR, "crypto: cannot install certificate: %s", ERR_reason_error_string(ERR_get_error()));
 307         }
 308
 309         /* Finally let the server know we're here */
 310         CtdlRegisterProtoHook(cmd_stls, "STLS", "Start SSL/TLS session");
 311         CtdlRegisterProtoHook(cmd_gtls, "GTLS", "Get SSL/TLS session status");
 312         CtdlRegisterSessionHook(endtls, EVT_STOP, PRIO_STOP + 10);
 313 }
 314
 315
 316 /*
 317  * client_write_ssl() Send binary data to the client encrypted.
 318  */
 319 void client_write_ssl(const char *buf, int nbytes)
 320 {
 321         int retval;
 322         int nremain;
 323         char junk[1];
 324
 325         nremain = nbytes;
 326
 327         while (nremain > 0) {
 328                 if (SSL_want_write(CC->ssl)) {
 329                         if ((SSL_read(CC->ssl, junk, 0)) < 1) {
 330                                 syslog(LOG_DEBUG, "crypto: SSL_read in client_write: %s", ERR_reason_error_string(ERR_get_error()));
 331                         }
 332                 }
 333                 retval =
 334                     SSL_write(CC->ssl, &buf[nbytes - nremain], nremain);
 335                 if (retval < 1) {
 336                         long errval;
 337
 338                         errval = SSL_get_error(CC->ssl, retval);
 339                         if (errval == SSL_ERROR_WANT_READ ||
 340                             errval == SSL_ERROR_WANT_WRITE) {
 341                                 sleep(1);
 342                                 continue;
 343                         }
 344                         syslog(LOG_DEBUG, "crypto: SSL_write got error %ld, ret %d", errval, retval);
 345                         if (retval == -1) {
 346                                 syslog(LOG_DEBUG, "crypto: errno is %d", errno);
 347                         }
 348                         endtls();
 349                         client_write(&buf[nbytes - nremain], nremain);
 350                         return;
 351                 }
 352                 nremain -= retval;
 353         }
 354 }
 355
 356
 357 /*
 358  * read data from the encrypted layer.
 359  */
 360 int client_read_sslbuffer(StrBuf *buf, int timeout)
 361 {
 362         char sbuf[16384]; /* OpenSSL communicates in 16k blocks, so let's speak its native tongue. */
 363         int rlen;
 364         char junk[1];
 365         SSL *pssl = CC->ssl;
 366
 367         if (pssl == NULL) return(-1);
 368
 369         while (1) {
 370                 if (SSL_want_read(pssl)) {
 371                         if ((SSL_write(pssl, junk, 0)) < 1) {
 372                                 syslog(LOG_DEBUG, "crypto: SSL_write in client_read");
 373                         }
 374                 }
 375                 rlen = SSL_read(pssl, sbuf, sizeof(sbuf));
 376                 if (rlen < 1) {
 377                         long errval;
 378
 379                         errval = SSL_get_error(pssl, rlen);
 380                         if (errval == SSL_ERROR_WANT_READ || errval == SSL_ERROR_WANT_WRITE) {
 381                                 sleep(1);
 382                                 continue;
 383                         }
 384                         syslog(LOG_DEBUG, "crypto: SSL_read got error %ld", errval);
 385                         endtls();
 386                         return (-1);
 387                 }
 388                 StrBufAppendBufPlain(buf, sbuf, rlen, 0);
 389                 return rlen;
 390         }
 391         return (0);
 392 }
 393
 394 int client_readline_sslbuffer(StrBuf *Line, StrBuf *IOBuf, const char **Pos, int timeout)
 395 {
 396         CitContext *CCC = CC;
 397         const char *pos = NULL;
 398         const char *pLF;
 399         int len, rlen;
 400         int nSuccessLess = 0;
 401         const char *pch = NULL;
 402
 403         if ((Line == NULL) || (Pos == NULL) || (IOBuf == NULL))
 404         {
 405                 if (Pos != NULL)
 406                 {
 407                         *Pos = NULL;
 408                 }
 409                 return -1;
 410         }
 411
 412         pos = *Pos;
 413         if ((StrLength(IOBuf) > 0) && (pos != NULL) && (pos < ChrPtr(IOBuf) + StrLength(IOBuf)))
 414         {
 415                 pch = pos;
 416                 pch = strchr(pch, '\n');
 417
 418                 if (pch == NULL) {
 419                         StrBufAppendBufPlain(Line, pos, StrLength(IOBuf) - (pos - ChrPtr(IOBuf)), 0);
 420                         FlushStrBuf(IOBuf);
 421                         *Pos = NULL;
 422                 }
 423                 else {
 424                         int n = 0;
 425                         if ((pch > ChrPtr(IOBuf)) &&
 426                             (*(pch - 1) == '\r')) {
 427                                 n = 1;
 428                         }
 429                         StrBufAppendBufPlain(Line, pos,
 430                                              (pch - pos - n), 0);
 431
 432                         if (StrLength(IOBuf) <= (pch - ChrPtr(IOBuf) + 1)) {
 433                                 FlushStrBuf(IOBuf);
 434                                 *Pos = NULL;
 435                         }
 436                         else
 437                                 *Pos = pch + 1;
 438                         return StrLength(Line);
 439                 }
 440         }
 441
 442         pLF = NULL;
 443         while ((nSuccessLess < timeout) &&
 444                (pLF == NULL) &&
 445                (CCC->ssl != NULL)) {
 446
 447                 rlen = client_read_sslbuffer(IOBuf, timeout);
 448                 if (rlen < 1) {
 449                         return -1;
 450                 }
 451                 else if (rlen > 0) {
 452                         pLF = strchr(ChrPtr(IOBuf), '\n');
 453                 }
 454         }
 455         *Pos = NULL;
 456         if (pLF != NULL) {
 457                 pos = ChrPtr(IOBuf);
 458                 len = pLF - pos;
 459                 if (len > 0 && (*(pLF - 1) == '\r') )
 460                         len --;
 461                 StrBufAppendBufPlain(Line, pos, len, 0);
 462                 if (pLF + 1 >= ChrPtr(IOBuf) + StrLength(IOBuf))
 463                 {
 464                         FlushStrBuf(IOBuf);
 465                 }
 466                 else
 467                         *Pos = pLF + 1;
 468                 return StrLength(Line);
 469         }
 470         return -1;
 471 }
 472
 473
 474 int client_read_sslblob(StrBuf *Target, long bytes, int timeout)
 475 {
 476         long baselen;
 477         long RemainRead;
 478         int retval = 0;
 479         CitContext *CCC = CC;
 480
 481         baselen = StrLength(Target);
 482
 483         if (StrLength(CCC->RecvBuf.Buf) > 0)
 484         {
 485                 long RemainLen;
 486                 long TotalLen;
 487                 const char *pchs;
 488
 489                 if (CCC->RecvBuf.ReadWritePointer == NULL)
 490                 {
 491                         CCC->RecvBuf.ReadWritePointer = ChrPtr(CCC->RecvBuf.Buf);
 492                 }
 493                 pchs = ChrPtr(CCC->RecvBuf.Buf);
 494                 TotalLen = StrLength(CCC->RecvBuf.Buf);
 495                 RemainLen = TotalLen - (pchs - CCC->RecvBuf.ReadWritePointer);
 496                 if (RemainLen > bytes)
 497                 {
 498                         RemainLen = bytes;
 499                 }
 500                 if (RemainLen > 0)
 501                 {
 502                         StrBufAppendBufPlain(Target, CCC->RecvBuf.ReadWritePointer, RemainLen, 0);
 503                         CCC->RecvBuf.ReadWritePointer += RemainLen;
 504                 }
 505                 if ((ChrPtr(CCC->RecvBuf.Buf) + StrLength(CCC->RecvBuf.Buf)) <= CCC->RecvBuf.ReadWritePointer)
 506                 {
 507                         CCC->RecvBuf.ReadWritePointer = NULL;
 508                         FlushStrBuf(CCC->RecvBuf.Buf);
 509                 }
 510         }
 511
 512         if (StrLength(Target) >= bytes + baselen)
 513         {
 514                 return 1;
 515         }
 516
 517         CCC->RecvBuf.ReadWritePointer = NULL;
 518
 519         while ((StrLength(Target) < bytes + baselen) && (retval >= 0))
 520         {
 521                 retval = client_read_sslbuffer(CCC->RecvBuf.Buf, timeout);
 522                 if (retval >= 0) {
 523                         RemainRead = bytes - (StrLength (Target) - baselen);
 524                         if (RemainRead < StrLength(CCC->RecvBuf.Buf))
 525                         {
 526                                 StrBufAppendBufPlain(
 527                                         Target,
 528                                         ChrPtr(CCC->RecvBuf.Buf),
 529                                         RemainRead, 0);
 530                                 CCC->RecvBuf.ReadWritePointer = ChrPtr(CCC->RecvBuf.Buf) + RemainRead;
 531                                 break;
 532                         }
 533                         StrBufAppendBuf(Target, CCC->RecvBuf.Buf, 0); /* todo: Buf > bytes? */
 534                         FlushStrBuf(CCC->RecvBuf.Buf);
 535                 }
 536                 else
 537                 {
 538                         FlushStrBuf(CCC->RecvBuf.Buf);
 539                         return -1;
 540
 541                 }
 542         }
 543         return 1;
 544 }
 545
 546
 547 /*
 548  * CtdlStartTLS() starts SSL/TLS encryption for the current session.  It
 549  * must be supplied with pre-generated strings for responses of "ok," "no
 550  * support for TLS," and "error" so that we can use this in any protocol.
 551  */
 552 void CtdlStartTLS(char *ok_response, char *nosup_response, char *error_response)
 553 {
 554         int retval, bits, alg_bits;
 555
 556         if (!ssl_ctx) {
 557                 syslog(LOG_ERR, "crypto: SSL failed: no ssl_ctx exists?");
 558                 if (nosup_response != NULL) cprintf("%s", nosup_response);
 559                 return;
 560         }
 561         if (!(CC->ssl = SSL_new(ssl_ctx))) {
 562                 syslog(LOG_ERR, "crypto: SSL_new failed: %s", ERR_reason_error_string(ERR_get_error()));
 563                 if (error_response != NULL) {
 564                         cprintf("%s", error_response);
 565                 }
 566                 return;
 567         }
 568         if (!(SSL_set_fd(CC->ssl, CC->client_socket))) {
 569                 syslog(LOG_ERR, "crypto: SSL_set_fd failed: %s", ERR_reason_error_string(ERR_get_error()));
 570                 SSL_free(CC->ssl);
 571                 CC->ssl = NULL;
 572                 if (error_response != NULL) cprintf("%s", error_response);
 573                 return;
 574         }
 575         if (ok_response != NULL) cprintf("%s", ok_response);
 576         retval = SSL_accept(CC->ssl);
 577         if (retval < 1) {
 578                 /*
 579                  * Can't notify the client of an error here; they will
 580                  * discover the problem at the SSL layer and should
 581                  * revert to unencrypted communications.
 582                  */
 583                 long errval;
 584                 char error_string[128];
 585
 586                 errval = SSL_get_error(CC->ssl, retval);
 587                 syslog(LOG_ERR, "crypto: SSL_accept failed: retval=%d, errval=%ld, err=%s",
 588                         retval,
 589                         errval,
 590                         ERR_error_string(errval, error_string)
 591                 );
 592                 SSL_free(CC->ssl);
 593                 CC->ssl = NULL;
 594                 return;
 595         }
 596         // BIO_set_close(CC->ssl->rbio, BIO_NOCLOSE); not needed anymore in openssl 1.1 ?
 597         bits = SSL_CIPHER_get_bits(SSL_get_current_cipher(CC->ssl), &alg_bits);
 598         syslog(LOG_INFO, "crypto: SSL/TLS using %s on %s (%d of %d bits)",
 599                 SSL_CIPHER_get_name(SSL_get_current_cipher(CC->ssl)),
 600                 SSL_CIPHER_get_version(SSL_get_current_cipher(CC->ssl)),
 601                 bits, alg_bits
 602         );
 603         CC->redirect_ssl = 1;
 604 }
 605
 606
 607 /*
 608  * cmd_stls() starts SSL/TLS encryption for the current session
 609  */
 610 void cmd_stls(char *params)
 611 {
 612         char ok_response[SIZ];
 613         char nosup_response[SIZ];
 614         char error_response[SIZ];
 615
 616         unbuffer_output();
 617
 618         sprintf(ok_response, "%d Begin TLS negotiation now\n", CIT_OK);
 619         sprintf(nosup_response, "%d TLS not supported here\n", ERROR + CMD_NOT_SUPPORTED);
 620         sprintf(error_response, "%d TLS negotiation error\n", ERROR + INTERNAL_ERROR);
 621
 622         CtdlStartTLS(ok_response, nosup_response, error_response);
 623 }
 624
 625
 626 /*
 627  * cmd_gtls() returns status info about the TLS connection
 628  */
 629 void cmd_gtls(char *params)
 630 {
 631         int bits, alg_bits;
 632
 633         if (!CC->ssl || !CC->redirect_ssl) {
 634                 cprintf("%d Session is not encrypted.\n", ERROR);
 635                 return;
 636         }
 637         bits =
 638             SSL_CIPHER_get_bits(SSL_get_current_cipher(CC->ssl),
 639                                 &alg_bits);
 640         cprintf("%d %s|%s|%d|%d\n", CIT_OK,
 641                 SSL_CIPHER_get_version(SSL_get_current_cipher(CC->ssl)),
 642                 SSL_CIPHER_get_name(SSL_get_current_cipher(CC->ssl)),
 643                 alg_bits, bits);
 644 }
 645
 646
 647 /*
 648  * endtls() shuts down the TLS connection
 649  *
 650  * WARNING:  This may make your session vulnerable to a known plaintext
 651  * attack in the current implmentation.
 652  */
 653 void endtls(void)
 654 {
 655         if (!CC->ssl) {
 656                 CC->redirect_ssl = 0;
 657                 return;
 658         }
 659
 660         syslog(LOG_INFO, "crypto: ending SSL/TLS");
 661         SSL_shutdown(CC->ssl);
 662         SSL_free(CC->ssl);
 663         CC->ssl = NULL;
 664         CC->redirect_ssl = 0;
 665 }
 666
 667
 668 /*
 669  * ssl_lock() callback for OpenSSL mutex locks
 670  */
 671 void ssl_lock(int mode, int n, const char *file, int line)
 672 {
 673         if (mode & CRYPTO_LOCK)
 674         {
 675                 pthread_mutex_lock(SSLCritters[n]);
 676         }
 677         else {
 678                 pthread_mutex_unlock(SSLCritters[n]);
 679         }
 680 }
 681 #endif                          /* HAVE_OPENSSL */