citadel/server/modules/crypto/serv_crypto.c

   1 // Copyright (c) 1987-2022 by the citadel.org team
   2 // This program is open source software.  Use, duplication, or disclosure is subject to the GNU General Public License v3.
   3
   4 #include <string.h>
   5 #include <unistd.h>
   6 #include <sys/stat.h>
   7 #include <sys/types.h>
   8 #include "../../sysdep.h"
   9
  10 #include <openssl/ssl.h>
  11 #include <openssl/err.h>
  12 #include <openssl/rand.h>
  13
  14 #include <time.h>
  15
  16 #ifdef HAVE_PTHREAD_H
  17 #include <pthread.h>
  18 #endif
  19
  20 #ifdef HAVE_SYS_SELECT_H
  21 #include <sys/select.h>
  22 #endif
  23
  24 #include <stdio.h>
  25 #include <libcitadel.h>
  26 #include "../../server.h"
  27 #include "serv_crypto.h"
  28 #include "../../sysdep_decls.h"
  29 #include "../../citadel_defs.h"
  30 #include "../../config.h"
  31 #include "../../ctdl_module.h"
  32
  33 SSL_CTX *ssl_ctx = NULL;                // This SSL context is used for all sessions.
  34 char *ssl_cipher_list = CIT_CIPHERS;
  35
  36 // If a private key does not exist, generate one now.
  37 void generate_key(char *keyfilename) {
  38         int ret = 0;
  39         RSA *rsa = NULL;
  40         BIGNUM *bne = NULL;
  41         int bits = 2048;
  42         unsigned long e = RSA_F4;
  43         FILE *fp;
  44
  45         if (access(keyfilename, R_OK) == 0) {   // Already have one.
  46                 syslog(LOG_INFO, "crypto: %s exists and is readable", keyfilename);
  47                 return;
  48         }
  49
  50         syslog(LOG_INFO, "crypto: generating RSA key pair");
  51
  52         // generate rsa key
  53         bne = BN_new();
  54         ret = BN_set_word(bne,e);
  55         if (ret != 1) {
  56                 goto free_all;
  57         }
  58
  59         rsa = RSA_new();
  60         ret = RSA_generate_key_ex(rsa, bits, bne, NULL);
  61         if (ret != 1) {
  62                 goto free_all;
  63         }
  64
  65         // write the key file
  66         fp = fopen(keyfilename, "w");
  67         if (fp != NULL) {
  68                 chmod(keyfilename, 0600);
  69                 if (PEM_write_RSAPrivateKey(fp, // the file
  70                                         rsa,    // the key
  71                                         NULL,   // no enc
  72                                         NULL,   // no passphrase
  73                                         0,      // no passphrase
  74                                         NULL,   // no callback
  75                                         NULL    // no callback
  76                 ) != 1) {
  77                         syslog(LOG_ERR, "crypto: cannot write key: %s", ERR_reason_error_string(ERR_get_error()));
  78                         unlink(keyfilename);
  79                 }
  80                 fclose(fp);
  81         }
  82
  83         // free the memory we used
  84 free_all:
  85         RSA_free(rsa);
  86         BN_free(bne);
  87 }
  88
  89
  90 // If a certificate does not exist, generate a self-signed one now.
  91 void generate_certificate(char *keyfilename, char *certfilename) {
  92         RSA *private_key = NULL;
  93         EVP_PKEY *public_key = NULL;
  94         X509_REQ *certificate_signing_request = NULL;
  95         X509_NAME *name = NULL;
  96         X509 *certificate = NULL;
  97         FILE *fp;
  98
  99         if (access(certfilename, R_OK) == 0) {                  // already have one.
 100                 syslog(LOG_INFO, "crypto: %s exists and is readable", certfilename);
 101                 return;
 102         }
 103
 104         syslog(LOG_INFO, "crypto: generating a self-signed certificate");
 105
 106         // Read in our private key.
 107         fp = fopen(keyfilename, "r");
 108         if (fp) {
 109                 private_key = PEM_read_RSAPrivateKey(fp, NULL, NULL, NULL);
 110                 fclose(fp);
 111         }
 112
 113         if (!private_key) {
 114                 syslog(LOG_ERR, "crypto: cannot read the private key");
 115                 return;
 116         }
 117
 118         // Create a public key from the private key
 119         public_key = EVP_PKEY_new();
 120         if (!public_key) {
 121                 syslog(LOG_ERR, "crypto: cannot allocate public key");
 122                 RSA_free(private_key);
 123                 return;
 124         }
 125         EVP_PKEY_assign_RSA(public_key, private_key);
 126
 127         // Create a certificate signing request
 128         certificate_signing_request = X509_REQ_new();
 129         if (!certificate_signing_request) {
 130                 syslog(LOG_ERR, "crypto: cannot allocate certificate signing request");
 131                 RSA_free(private_key);
 132                 EVP_PKEY_free(public_key);
 133                 return;
 134         }
 135
 136         // Assign the public key to the certificate signing request
 137         X509_REQ_set_pubkey(certificate_signing_request, public_key);
 138         X509_REQ_set_version(certificate_signing_request, 0L);
 139
 140         // Tell it who we are
 141         name = X509_REQ_get_subject_name(certificate_signing_request);
 142         X509_NAME_add_entry_by_txt(name, "C", MBSTRING_ASC, (unsigned const char *)"ZZ", -1, -1, 0);
 143         X509_NAME_add_entry_by_txt(name, "ST", MBSTRING_ASC, (unsigned const char *)"The World", -1, -1, 0);
 144         X509_NAME_add_entry_by_txt(name, "L", MBSTRING_ASC, (unsigned const char *)"My Location", -1, -1, 0);
 145         X509_NAME_add_entry_by_txt(name, "O", MBSTRING_ASC, (unsigned const char *)"Generic certificate", -1, -1, 0);
 146         X509_NAME_add_entry_by_txt(name, "OU", MBSTRING_ASC, (unsigned const char *)"Citadel server", -1, -1, 0);
 147         X509_NAME_add_entry_by_txt(name, "CN", MBSTRING_ASC, (unsigned const char *)"*", -1, -1, 0);
 148         X509_REQ_set_subject_name(certificate_signing_request, name);
 149
 150         // Sign the CSR
 151         //if (!X509_REQ_sign(certificate_signing_request, public_key, EVP_md5())) {
 152         if (!X509_REQ_sign(certificate_signing_request, public_key, EVP_md5()) , 0) {
 153                 syslog(LOG_ERR, "crypto: X509_REQ_sign(): error");
 154                 X509_REQ_free(certificate_signing_request);
 155                 RSA_free(private_key);
 156                 EVP_PKEY_free(public_key);
 157                 return;
 158         }
 159
 160         // Generate the self-signed certificate
 161         certificate = X509_new();
 162         if (!certificate) {
 163                 syslog(LOG_ERR, "crypto: cannot allocate X.509 certificate");
 164                 X509_REQ_free(certificate_signing_request);
 165                 RSA_free(private_key);
 166                 EVP_PKEY_free(public_key);
 167                 return;
 168         }
 169
 170         ASN1_INTEGER_set(X509_get_serialNumber(certificate), 0);
 171         X509_set_issuer_name(certificate, X509_REQ_get_subject_name(certificate_signing_request));
 172         X509_set_subject_name(certificate, X509_REQ_get_subject_name(certificate_signing_request));
 173         X509_gmtime_adj(X509_get_notBefore(certificate), 0);
 174         X509_gmtime_adj(X509_get_notAfter(certificate), (long)60*60*24*SIGN_DAYS);
 175         X509_set_pubkey(certificate, public_key);
 176         X509_REQ_free(certificate_signing_request);             // We're done with the CSR; free it
 177
 178         // Finally, sign the certificate with our private key.
 179         if (!X509_sign(certificate, public_key, EVP_md5())) {
 180                 syslog(LOG_ERR, "crypto: X509_sign() error");
 181                 X509_free(certificate);
 182                 RSA_free(private_key);
 183                 EVP_PKEY_free(public_key);
 184                 return;
 185         }
 186
 187         // Write the certificate to disk
 188         fp = fopen(certfilename, "w");
 189         if (fp != NULL) {
 190                 chmod(certfilename, 0600);
 191                 PEM_write_X509(fp, certificate);
 192                 fclose(fp);
 193         }
 194         else {
 195                 syslog(LOG_ERR, "crypto: %s: %m", certfilename);
 196         }
 197
 198         X509_free(certificate);
 199         EVP_PKEY_free(public_key);
 200         // do not RSA_free(private_key); because it was freed by EVP_PKEY_free() above
 201 }
 202
 203
 204 // Set the private key and certificate chain for the global SSL Context.
 205 // This is called during initialization, and can be called again later if the certificate changes.
 206 void bind_to_key_and_certificate(void) {
 207
 208         SSL_CTX *old_ctx = NULL;
 209         SSL_CTX *new_ctx = NULL;
 210
 211         const SSL_METHOD *method = SSLv23_server_method();
 212         if (!method) {
 213                 syslog(LOG_ERR, "crypto: SSLv23_server_method() failed: %s", ERR_reason_error_string(ERR_get_error()));
 214                 return;
 215         }
 216
 217         new_ctx = SSL_CTX_new(method);
 218         if (!new_ctx) {
 219                 syslog(LOG_ERR, "crypto: SSL_CTX_new failed: %s", ERR_reason_error_string(ERR_get_error()));
 220                 return;
 221         }
 222
 223         if (!(SSL_CTX_set_cipher_list(new_ctx, ssl_cipher_list))) {
 224                 syslog(LOG_ERR, "crypto: SSL_CTX_set_cipher_list failed: %s", ERR_reason_error_string(ERR_get_error()));
 225                 return;
 226         }
 227
 228         syslog(LOG_DEBUG, "crypto: using certificate chain %s", file_crpt_file_cer);
 229         if (!SSL_CTX_use_certificate_chain_file(new_ctx, file_crpt_file_cer)) {
 230                 syslog(LOG_ERR, "crypto: SSL_CTX_use_certificate_chain_file failed: %s", ERR_reason_error_string(ERR_get_error()));
 231                 return;
 232         }
 233
 234         syslog(LOG_DEBUG, "crypto: using private key %s", file_crpt_file_key);
 235         if (!SSL_CTX_use_PrivateKey_file(new_ctx, file_crpt_file_key, SSL_FILETYPE_PEM)) {
 236                 syslog(LOG_ERR, "crypto: SSL_CTX_use_PrivateKey_file failed: %s", ERR_reason_error_string(ERR_get_error()));
 237                 return;
 238         }
 239
 240         old_ctx = ssl_ctx;
 241         ssl_ctx = new_ctx;              // All future binds will use the new certificate
 242
 243         if (old_ctx != NULL) {
 244                 sleep(1);               // Hopefully wait until all in-progress binds to the old certificate have completed
 245                 SSL_CTX_free(old_ctx);
 246         }
 247 }
 248
 249
 250 // Check the modification time of the key and certificate files.  Reload if either one changed.
 251 void update_key_and_cert_if_needed(void) {
 252         static time_t previous_mtime = 0;
 253         struct stat keystat;
 254         struct stat certstat;
 255
 256         if (stat(file_crpt_file_key, &keystat) != 0) {
 257                 syslog(LOG_ERR, "%s: %s", file_crpt_file_key, strerror(errno));
 258                 return;
 259         }
 260         if (stat(file_crpt_file_cer, &certstat) != 0) {
 261                 syslog(LOG_ERR, "%s: %s", file_crpt_file_cer, strerror(errno));
 262                 return;
 263         }
 264
 265         if ((keystat.st_mtime + certstat.st_mtime) != previous_mtime) {
 266                 begin_critical_section(S_OPENSSL);
 267                 bind_to_key_and_certificate();
 268                 end_critical_section(S_OPENSSL);
 269                 previous_mtime = keystat.st_mtime + certstat.st_mtime;
 270         }
 271 }
 272
 273
 274 // Initialize the TLS subsystem.
 275 void init_ssl(void) {
 276
 277         // Initialize the OpenSSL library
 278         SSL_library_init();
 279         SSL_load_error_strings();
 280
 281         // Load (or generate) a key and certificate
 282         mkdir(ctdl_key_dir, 0700);                                      // If the keys directory does not exist, create it
 283         generate_key(file_crpt_file_key);                               // If a private key does not exist, create it
 284         generate_certificate(file_crpt_file_key, file_crpt_file_cer);   // If a certificate does not exist, create it
 285         bind_to_key_and_certificate();                                  // Load key and cert from disk, and bind to them.
 286
 287         // Register some Citadel protocol commands for dealing with encrypted sessions
 288         CtdlRegisterProtoHook(cmd_stls, "STLS", "Start TLS session");
 289         CtdlRegisterProtoHook(cmd_gtls, "GTLS", "Get TLS session status");
 290         CtdlRegisterSessionHook(endtls, EVT_STOP, PRIO_STOP + 10);
 291 }
 292
 293
 294 // client_write_ssl() Send binary data to the client encrypted.
 295 void client_write_ssl(const char *buf, int nbytes) {
 296         int retval;
 297         int nremain;
 298         char junk[1];
 299
 300         nremain = nbytes;
 301
 302         while (nremain > 0) {
 303                 if (SSL_want_write(CC->ssl)) {
 304                         if ((SSL_read(CC->ssl, junk, 0)) < 1) {
 305                                 syslog(LOG_DEBUG, "crypto: SSL_read in client_write: %s", ERR_reason_error_string(ERR_get_error()));
 306                         }
 307                 }
 308                 retval =
 309                     SSL_write(CC->ssl, &buf[nbytes - nremain], nremain);
 310                 if (retval < 1) {
 311                         long errval;
 312
 313                         errval = SSL_get_error(CC->ssl, retval);
 314                         if (errval == SSL_ERROR_WANT_READ || errval == SSL_ERROR_WANT_WRITE) {
 315                                 sleep(1);
 316                                 continue;
 317                         }
 318                         syslog(LOG_DEBUG, "crypto: SSL_write got error %ld, ret %d", errval, retval);
 319                         if (retval == -1) {
 320                                 syslog(LOG_DEBUG, "crypto: errno is %d", errno);
 321                         }
 322                         endtls();
 323                         client_write(&buf[nbytes - nremain], nremain);
 324                         return;
 325                 }
 326                 nremain -= retval;
 327         }
 328 }
 329
 330
 331 // read data from the encrypted layer.
 332 int client_read_sslbuffer(StrBuf *buf, int timeout) {
 333         char sbuf[16384];       // OpenSSL communicates in 16k blocks, so let's speak its native tongue.
 334         int rlen;
 335         char junk[1];
 336         SSL *pssl = CC->ssl;
 337
 338         if (pssl == NULL) return(-1);
 339
 340         while (1) {
 341                 if (SSL_want_read(pssl)) {
 342                         if ((SSL_write(pssl, junk, 0)) < 1) {
 343                                 syslog(LOG_DEBUG, "crypto: SSL_write in client_read");
 344                         }
 345                 }
 346                 rlen = SSL_read(pssl, sbuf, sizeof(sbuf));
 347                 if (rlen < 1) {
 348                         long errval;
 349
 350                         errval = SSL_get_error(pssl, rlen);
 351                         if (errval == SSL_ERROR_WANT_READ || errval == SSL_ERROR_WANT_WRITE) {
 352                                 sleep(1);
 353                                 continue;
 354                         }
 355                         syslog(LOG_DEBUG, "crypto: SSL_read got error %ld", errval);
 356                         endtls();
 357                         return (-1);
 358                 }
 359                 StrBufAppendBufPlain(buf, sbuf, rlen, 0);
 360                 return rlen;
 361         }
 362         return (0);
 363 }
 364
 365
 366 int client_readline_sslbuffer(StrBuf *Line, StrBuf *IOBuf, const char **Pos, int timeout) {
 367         const char *pos = NULL;
 368         const char *pLF;
 369         int len, rlen;
 370         int nSuccessLess = 0;
 371         const char *pch = NULL;
 372
 373         if ((Line == NULL) || (Pos == NULL) || (IOBuf == NULL)) {
 374                 if (Pos != NULL) {
 375                         *Pos = NULL;
 376                 }
 377                 return -1;
 378         }
 379
 380         pos = *Pos;
 381         if ((StrLength(IOBuf) > 0) && (pos != NULL) && (pos < ChrPtr(IOBuf) + StrLength(IOBuf))) {
 382                 pch = pos;
 383                 pch = strchr(pch, '\n');
 384
 385                 if (pch == NULL) {
 386                         StrBufAppendBufPlain(Line, pos, StrLength(IOBuf) - (pos - ChrPtr(IOBuf)), 0);
 387                         FlushStrBuf(IOBuf);
 388                         *Pos = NULL;
 389                 }
 390                 else {
 391                         int n = 0;
 392                         if ((pch > ChrPtr(IOBuf)) && (*(pch - 1) == '\r')) {
 393                                 n = 1;
 394                         }
 395                         StrBufAppendBufPlain(Line, pos, (pch - pos - n), 0);
 396
 397                         if (StrLength(IOBuf) <= (pch - ChrPtr(IOBuf) + 1)) {
 398                                 FlushStrBuf(IOBuf);
 399                                 *Pos = NULL;
 400                         }
 401                         else {
 402                                 *Pos = pch + 1;
 403                         }
 404                         return StrLength(Line);
 405                 }
 406         }
 407
 408         pLF = NULL;
 409         while ((nSuccessLess < timeout) && (pLF == NULL) && (CC->ssl != NULL)) {
 410
 411                 rlen = client_read_sslbuffer(IOBuf, timeout);
 412                 if (rlen < 1) {
 413                         return -1;
 414                 }
 415                 else if (rlen > 0) {
 416                         pLF = strchr(ChrPtr(IOBuf), '\n');
 417                 }
 418         }
 419         *Pos = NULL;
 420         if (pLF != NULL) {
 421                 pos = ChrPtr(IOBuf);
 422                 len = pLF - pos;
 423                 if (len > 0 && (*(pLF - 1) == '\r') )
 424                         len --;
 425                 StrBufAppendBufPlain(Line, pos, len, 0);
 426                 if (pLF + 1 >= ChrPtr(IOBuf) + StrLength(IOBuf)) {
 427                         FlushStrBuf(IOBuf);
 428                 }
 429                 else  {
 430                         *Pos = pLF + 1;
 431                 }
 432                 return StrLength(Line);
 433         }
 434         return -1;
 435 }
 436
 437
 438 int client_read_sslblob(StrBuf *Target, long bytes, int timeout) {
 439         long baselen;
 440         long RemainRead;
 441         int retval = 0;
 442
 443         baselen = StrLength(Target);
 444
 445         if (StrLength(CC->RecvBuf.Buf) > 0) {
 446                 long RemainLen;
 447                 long TotalLen;
 448                 const char *pchs;
 449
 450                 if (CC->RecvBuf.ReadWritePointer == NULL) {
 451                         CC->RecvBuf.ReadWritePointer = ChrPtr(CC->RecvBuf.Buf);
 452                 }
 453                 pchs = ChrPtr(CC->RecvBuf.Buf);
 454                 TotalLen = StrLength(CC->RecvBuf.Buf);
 455                 RemainLen = TotalLen - (pchs - CC->RecvBuf.ReadWritePointer);
 456                 if (RemainLen > bytes) {
 457                         RemainLen = bytes;
 458                 }
 459                 if (RemainLen > 0) {
 460                         StrBufAppendBufPlain(Target, CC->RecvBuf.ReadWritePointer, RemainLen, 0);
 461                         CC->RecvBuf.ReadWritePointer += RemainLen;
 462                 }
 463                 if ((ChrPtr(CC->RecvBuf.Buf) + StrLength(CC->RecvBuf.Buf)) <= CC->RecvBuf.ReadWritePointer) {
 464                         CC->RecvBuf.ReadWritePointer = NULL;
 465                         FlushStrBuf(CC->RecvBuf.Buf);
 466                 }
 467         }
 468
 469         if (StrLength(Target) >= bytes + baselen) {
 470                 return 1;
 471         }
 472
 473         CC->RecvBuf.ReadWritePointer = NULL;
 474
 475         while ((StrLength(Target) < bytes + baselen) && (retval >= 0)) {
 476                 retval = client_read_sslbuffer(CC->RecvBuf.Buf, timeout);
 477                 if (retval >= 0) {
 478                         RemainRead = bytes - (StrLength (Target) - baselen);
 479                         if (RemainRead < StrLength(CC->RecvBuf.Buf)) {
 480                                 StrBufAppendBufPlain(
 481                                         Target,
 482                                         ChrPtr(CC->RecvBuf.Buf),
 483                                         RemainRead, 0);
 484                                 CC->RecvBuf.ReadWritePointer = ChrPtr(CC->RecvBuf.Buf) + RemainRead;
 485                                 break;
 486                         }
 487                         StrBufAppendBuf(Target, CC->RecvBuf.Buf, 0);
 488                         FlushStrBuf(CC->RecvBuf.Buf);
 489                 }
 490                 else {
 491                         FlushStrBuf(CC->RecvBuf.Buf);
 492                         return -1;
 493
 494                 }
 495         }
 496         return 1;
 497 }
 498
 499
 500 // CtdlStartTLS() starts TLS encryption for the current session.  It
 501 // must be supplied with pre-generated strings for responses of "ok," "no
 502 // support for TLS," and "error" so that we can use this in any protocol.
 503 void CtdlStartTLS(char *ok_response, char *nosup_response, char *error_response) {
 504         int retval, bits, alg_bits;
 505
 506         if (CC->redirect_ssl) {
 507                 syslog(LOG_ERR, "crypto: attempt to begin SSL on an already encrypted connection");
 508                 if (error_response != NULL) {
 509                         cprintf("%s", error_response);
 510                 }
 511                 return;
 512         }
 513
 514         if (!ssl_ctx) {
 515                 syslog(LOG_ERR, "crypto: SSL failed: ../../context.has not been initialized");
 516                 if (nosup_response != NULL) {
 517                         cprintf("%s", nosup_response);
 518                 }
 519                 return;
 520         }
 521
 522         update_key_and_cert_if_needed();                // did someone update the key or cert?  if so, re-bind them
 523
 524         if (!(CC->ssl = SSL_new(ssl_ctx))) {
 525                 syslog(LOG_ERR, "crypto: SSL_new failed: %s", ERR_reason_error_string(ERR_get_error()));
 526                 if (error_response != NULL) {
 527                         cprintf("%s", error_response);
 528                 }
 529                 return;
 530         }
 531         if (!(SSL_set_fd(CC->ssl, CC->client_socket))) {
 532                 syslog(LOG_ERR, "crypto: SSL_set_fd failed: %s", ERR_reason_error_string(ERR_get_error()));
 533                 SSL_free(CC->ssl);
 534                 CC->ssl = NULL;
 535                 if (error_response != NULL) {
 536                         cprintf("%s", error_response);
 537                 }
 538                 return;
 539         }
 540         if (ok_response != NULL) {
 541                 cprintf("%s", ok_response);
 542         }
 543         retval = SSL_accept(CC->ssl);
 544         if (retval < 1) {
 545                 // Can't notify the client of an error here; they will
 546                 // discover the problem at the SSL layer and should
 547                 // revert to unencrypted communications.
 548                 syslog(LOG_ERR, "crypto: SSL_accept failed: %s", ERR_reason_error_string(ERR_get_error()));
 549                 SSL_free(CC->ssl);
 550                 CC->ssl = NULL;
 551                 return;
 552         }
 553         bits = SSL_CIPHER_get_bits(SSL_get_current_cipher(CC->ssl), &alg_bits);
 554         syslog(LOG_INFO, "crypto: TLS using %s on %s (%d of %d bits)",
 555                 SSL_CIPHER_get_name(SSL_get_current_cipher(CC->ssl)),
 556                 SSL_CIPHER_get_version(SSL_get_current_cipher(CC->ssl)),
 557                 bits, alg_bits
 558         );
 559         CC->redirect_ssl = 1;
 560 }
 561
 562
 563 // cmd_stls() starts TLS encryption for the current session
 564 void cmd_stls(char *params) {
 565         char ok_response[SIZ];
 566         char nosup_response[SIZ];
 567         char error_response[SIZ];
 568
 569         unbuffer_output();
 570
 571         sprintf(ok_response, "%d Begin TLS negotiation now\n", CIT_OK);
 572         sprintf(nosup_response, "%d TLS not supported here\n", ERROR + CMD_NOT_SUPPORTED);
 573         sprintf(error_response, "%d TLS negotiation error\n", ERROR + INTERNAL_ERROR);
 574
 575         CtdlStartTLS(ok_response, nosup_response, error_response);
 576 }
 577
 578
 579 // cmd_gtls() returns status info about the TLS connection
 580 void cmd_gtls(char *params) {
 581         int bits, alg_bits;
 582
 583         if (!CC->ssl || !CC->redirect_ssl) {
 584                 cprintf("%d Session is not encrypted.\n", ERROR);
 585                 return;
 586         }
 587         bits = SSL_CIPHER_get_bits(SSL_get_current_cipher(CC->ssl), &alg_bits);
 588         cprintf("%d %s|%s|%d|%d\n", CIT_OK,
 589                 SSL_CIPHER_get_version(SSL_get_current_cipher(CC->ssl)),
 590                 SSL_CIPHER_get_name(SSL_get_current_cipher(CC->ssl)),
 591                 alg_bits, bits);
 592 }
 593
 594
 595 // endtls() shuts down the TLS connection
 596 void endtls(void) {
 597         if (!CC->ssl) {
 598                 CC->redirect_ssl = 0;
 599                 return;
 600         }
 601
 602         syslog(LOG_INFO, "crypto: ending TLS on this session");
 603         SSL_shutdown(CC->ssl);
 604         SSL_free(CC->ssl);
 605         CC->ssl = NULL;
 606         CC->redirect_ssl = 0;
 607 }