cups/tls-gnutls.c

   1 /*
   2  * TLS support code for CUPS using GNU TLS.
   3  *
   4  * Copyright 2007-2017 by Apple Inc.
   5  * Copyright 1997-2007 by Easy Software Products, all rights reserved.
   6  *
   7  * These coded instructions, statements, and computer programs are the
   8  * property of Apple Inc. and are protected by Federal copyright
   9  * law.  Distribution and use rights are outlined in the file "LICENSE.txt"
  10  * which should have been included with this file.  If this file is
  11  * missing or damaged, see the license at "http://www.cups.org/".
  12  *
  13  * This file is subject to the Apple OS-Developed Software exception.
  14  */
  15
  16 /**** This file is included from tls.c ****/
  17
  18 /*
  19  * Include necessary headers...
  20  */
  21
  22 #include <sys/stat.h>
  23
  24
  25 /*
  26  * Local globals...
  27  */
  28
  29 static int              tls_auto_create = 0;
  30                                         /* Auto-create self-signed certs? */
  31 static char             *tls_common_name = NULL;
  32                                         /* Default common name */
  33 static gnutls_x509_crl_t tls_crl = NULL;/* Certificate revocation list */
  34 static char             *tls_keypath = NULL;
  35                                         /* Server cert keychain path */
  36 static _cups_mutex_t    tls_mutex = _CUPS_MUTEX_INITIALIZER;
  37                                         /* Mutex for keychain/certs */
  38 static int              tls_options = -1,/* Options for TLS connections */
  39                         tls_min_version = _HTTP_TLS_1_0,
  40                         tls_max_version = _HTTP_TLS_MAX;
  41
  42
  43 /*
  44  * Local functions...
  45  */
  46
  47 static gnutls_x509_crt_t http_gnutls_create_credential(http_credential_t *credential);
  48 static const char       *http_gnutls_default_path(char *buffer, size_t bufsize);
  49 static void             http_gnutls_load_crl(void);
  50 static const char       *http_gnutls_make_path(char *buffer, size_t bufsize, const char *dirname, const char *filename, const char *ext);
  51 static ssize_t          http_gnutls_read(gnutls_transport_ptr_t ptr, void *data, size_t length);
  52 static ssize_t          http_gnutls_write(gnutls_transport_ptr_t ptr, const void *data, size_t length);
  53
  54
  55 /*
  56  * 'cupsMakeServerCredentials()' - Make a self-signed certificate and private key pair.
  57  *
  58  * @since CUPS 2.0/OS 10.10@
  59  */
  60
  61 int                                     /* O - 1 on success, 0 on failure */
  62 cupsMakeServerCredentials(
  63     const char *path,                   /* I - Path to keychain/directory */
  64     const char *common_name,            /* I - Common name */
  65     int        num_alt_names,           /* I - Number of subject alternate names */
  66     const char **alt_names,             /* I - Subject Alternate Names */
  67     time_t     expiration_date)         /* I - Expiration date */
  68 {
  69   gnutls_x509_crt_t     crt;            /* Self-signed certificate */
  70   gnutls_x509_privkey_t key;            /* Encryption private key */
  71   char                  temp[1024],     /* Temporary directory name */
  72                         crtfile[1024],  /* Certificate filename */
  73                         keyfile[1024];  /* Private key filename */
  74   cups_lang_t           *language;      /* Default language info */
  75   cups_file_t           *fp;            /* Key/cert file */
  76   unsigned char         buffer[8192];   /* Buffer for x509 data */
  77   size_t                bytes;          /* Number of bytes of data */
  78   unsigned char         serial[4];      /* Serial number buffer */
  79   time_t                curtime;        /* Current time */
  80   int                   result;         /* Result of GNU TLS calls */
  81
  82
  83   DEBUG_printf(("cupsMakeServerCredentials(path=\"%s\", common_name=\"%s\", num_alt_names=%d, alt_names=%p, expiration_date=%d)", path, common_name, num_alt_names, alt_names, (int)expiration_date));
  84
  85  /*
  86   * Filenames...
  87   */
  88
  89   if (!path)
  90     path = http_gnutls_default_path(temp, sizeof(temp));
  91
  92   if (!path || !common_name)
  93   {
  94     _cupsSetError(IPP_STATUS_ERROR_INTERNAL, strerror(EINVAL), 0);
  95     return (0);
  96   }
  97
  98   http_gnutls_make_path(crtfile, sizeof(crtfile), path, common_name, "crt");
  99   http_gnutls_make_path(keyfile, sizeof(keyfile), path, common_name, "key");
 100
 101  /*
 102   * Create the encryption key...
 103   */
 104
 105   DEBUG_puts("1cupsMakeServerCredentials: Creating key pair.");
 106
 107   gnutls_x509_privkey_init(&key);
 108   gnutls_x509_privkey_generate(key, GNUTLS_PK_RSA, 2048, 0);
 109
 110   DEBUG_puts("1cupsMakeServerCredentials: Key pair created.");
 111
 112  /*
 113   * Save it...
 114   */
 115
 116   bytes = sizeof(buffer);
 117
 118   if ((result = gnutls_x509_privkey_export(key, GNUTLS_X509_FMT_PEM, buffer, &bytes)) < 0)
 119   {
 120     DEBUG_printf(("1cupsMakeServerCredentials: Unable to export private key: %s", gnutls_strerror(result)));
 121     _cupsSetError(IPP_STATUS_ERROR_INTERNAL, gnutls_strerror(result), 0);
 122     gnutls_x509_privkey_deinit(key);
 123     return (0);
 124   }
 125   else if ((fp = cupsFileOpen(keyfile, "w")) != NULL)
 126   {
 127     DEBUG_printf(("1cupsMakeServerCredentials: Writing private key to \"%s\".", keyfile));
 128     cupsFileWrite(fp, (char *)buffer, bytes);
 129     cupsFileClose(fp);
 130   }
 131   else
 132   {
 133     DEBUG_printf(("1cupsMakeServerCredentials: Unable to create private key file \"%s\": %s", keyfile, strerror(errno)));
 134     _cupsSetError(IPP_STATUS_ERROR_INTERNAL, strerror(errno), 0);
 135     gnutls_x509_privkey_deinit(key);
 136     return (0);
 137   }
 138
 139  /*
 140   * Create the self-signed certificate...
 141   */
 142
 143   DEBUG_puts("1cupsMakeServerCredentials: Generating self-signed X.509 certificate.");
 144
 145   language  = cupsLangDefault();
 146   curtime   = time(NULL);
 147   serial[0] = curtime >> 24;
 148   serial[1] = curtime >> 16;
 149   serial[2] = curtime >> 8;
 150   serial[3] = curtime;
 151
 152   gnutls_x509_crt_init(&crt);
 153   if (strlen(language->language) == 5)
 154     gnutls_x509_crt_set_dn_by_oid(crt, GNUTLS_OID_X520_COUNTRY_NAME, 0,
 155                                   language->language + 3, 2);
 156   else
 157     gnutls_x509_crt_set_dn_by_oid(crt, GNUTLS_OID_X520_COUNTRY_NAME, 0,
 158                                   "US", 2);
 159   gnutls_x509_crt_set_dn_by_oid(crt, GNUTLS_OID_X520_COMMON_NAME, 0,
 160                                 common_name, strlen(common_name));
 161   gnutls_x509_crt_set_dn_by_oid(crt, GNUTLS_OID_X520_ORGANIZATION_NAME, 0,
 162                                 common_name, strlen(common_name));
 163   gnutls_x509_crt_set_dn_by_oid(crt, GNUTLS_OID_X520_ORGANIZATIONAL_UNIT_NAME,
 164                                 0, "Unknown", 7);
 165   gnutls_x509_crt_set_dn_by_oid(crt, GNUTLS_OID_X520_STATE_OR_PROVINCE_NAME, 0,
 166                                 "Unknown", 7);
 167   gnutls_x509_crt_set_dn_by_oid(crt, GNUTLS_OID_X520_LOCALITY_NAME, 0,
 168                                 "Unknown", 7);
 169 /*  gnutls_x509_crt_set_dn_by_oid(crt, GNUTLS_OID_PKCS9_EMAIL, 0,
 170                                 ServerAdmin, strlen(ServerAdmin));*/
 171   gnutls_x509_crt_set_key(crt, key);
 172   gnutls_x509_crt_set_serial(crt, serial, sizeof(serial));
 173   gnutls_x509_crt_set_activation_time(crt, curtime);
 174   gnutls_x509_crt_set_expiration_time(crt, curtime + 10 * 365 * 86400);
 175   gnutls_x509_crt_set_ca_status(crt, 0);
 176   if (num_alt_names > 0)
 177     gnutls_x509_crt_set_subject_alternative_name(crt, GNUTLS_SAN_DNSNAME, alt_names[0]);
 178   gnutls_x509_crt_set_key_purpose_oid(crt, GNUTLS_KP_TLS_WWW_SERVER, 0);
 179   gnutls_x509_crt_set_key_usage(crt, GNUTLS_KEY_KEY_ENCIPHERMENT);
 180   gnutls_x509_crt_set_version(crt, 3);
 181
 182   bytes = sizeof(buffer);
 183   if (gnutls_x509_crt_get_key_id(crt, 0, buffer, &bytes) >= 0)
 184     gnutls_x509_crt_set_subject_key_id(crt, buffer, bytes);
 185
 186   gnutls_x509_crt_sign(crt, crt, key);
 187
 188  /*
 189   * Save it...
 190   */
 191
 192   bytes = sizeof(buffer);
 193   if ((result = gnutls_x509_crt_export(crt, GNUTLS_X509_FMT_PEM, buffer, &bytes)) < 0)
 194   {
 195     DEBUG_printf(("1cupsMakeServerCredentials: Unable to export public key and X.509 certificate: %s", gnutls_strerror(result)));
 196     _cupsSetError(IPP_STATUS_ERROR_INTERNAL, gnutls_strerror(result), 0);
 197     gnutls_x509_crt_deinit(crt);
 198     gnutls_x509_privkey_deinit(key);
 199     return (0);
 200   }
 201   else if ((fp = cupsFileOpen(crtfile, "w")) != NULL)
 202   {
 203     DEBUG_printf(("1cupsMakeServerCredentials: Writing public key and X.509 certificate to \"%s\".", crtfile));
 204     cupsFileWrite(fp, (char *)buffer, bytes);
 205     cupsFileClose(fp);
 206   }
 207   else
 208   {
 209     DEBUG_printf(("1cupsMakeServerCredentials: Unable to create public key and X.509 certificate file \"%s\": %s", crtfile, strerror(errno)));
 210     _cupsSetError(IPP_STATUS_ERROR_INTERNAL, strerror(errno), 0);
 211     gnutls_x509_crt_deinit(crt);
 212     gnutls_x509_privkey_deinit(key);
 213     return (0);
 214   }
 215
 216  /*
 217   * Cleanup...
 218   */
 219
 220   gnutls_x509_crt_deinit(crt);
 221   gnutls_x509_privkey_deinit(key);
 222
 223   DEBUG_puts("1cupsMakeServerCredentials: Successfully created credentials.");
 224
 225   return (1);
 226 }
 227
 228
 229 /*
 230  * 'cupsSetServerCredentials()' - Set the default server credentials.
 231  *
 232  * Note: The server credentials are used by all threads in the running process.
 233  * This function is threadsafe.
 234  *
 235  * @since CUPS 2.0/OS 10.10@
 236  */
 237
 238 int                                     /* O - 1 on success, 0 on failure */
 239 cupsSetServerCredentials(
 240     const char *path,                   /* I - Path to keychain/directory */
 241     const char *common_name,            /* I - Default common name for server */
 242     int        auto_create)             /* I - 1 = automatically create self-signed certificates */
 243 {
 244   char  temp[1024];                     /* Default path buffer */
 245
 246
 247   DEBUG_printf(("cupsSetServerCredentials(path=\"%s\", common_name=\"%s\", auto_create=%d)", path, common_name, auto_create));
 248
 249  /*
 250   * Use defaults as needed...
 251   */
 252
 253   if (!path)
 254     path = http_gnutls_default_path(temp, sizeof(temp));
 255
 256  /*
 257   * Range check input...
 258   */
 259
 260   if (!path || !common_name)
 261   {
 262     _cupsSetError(IPP_STATUS_ERROR_INTERNAL, strerror(EINVAL), 0);
 263     return (0);
 264   }
 265
 266   _cupsMutexLock(&tls_mutex);
 267
 268  /*
 269   * Free old values...
 270   */
 271
 272   if (tls_keypath)
 273     _cupsStrFree(tls_keypath);
 274
 275   if (tls_common_name)
 276     _cupsStrFree(tls_common_name);
 277
 278  /*
 279   * Save the new values...
 280   */
 281
 282   tls_keypath     = _cupsStrAlloc(path);
 283   tls_auto_create = auto_create;
 284   tls_common_name = _cupsStrAlloc(common_name);
 285
 286   _cupsMutexUnlock(&tls_mutex);
 287
 288   return (1);
 289 }
 290
 291
 292 /*
 293  * 'httpCopyCredentials()' - Copy the credentials associated with the peer in
 294  *                           an encrypted connection.
 295  *
 296  * @since CUPS 1.5/macOS 10.7@
 297  */
 298
 299 int                                     /* O - Status of call (0 = success) */
 300 httpCopyCredentials(
 301     http_t       *http,                 /* I - Connection to server */
 302     cups_array_t **credentials)         /* O - Array of credentials */
 303 {
 304   unsigned              count;          /* Number of certificates */
 305   const gnutls_datum_t *certs;          /* Certificates */
 306
 307
 308   DEBUG_printf(("httpCopyCredentials(http=%p, credentials=%p)", http, credentials));
 309
 310   if (credentials)
 311     *credentials = NULL;
 312
 313   if (!http || !http->tls || !credentials)
 314     return (-1);
 315
 316   *credentials = cupsArrayNew(NULL, NULL);
 317   certs        = gnutls_certificate_get_peers(http->tls, &count);
 318
 319   DEBUG_printf(("1httpCopyCredentials: certs=%p, count=%u", certs, count));
 320
 321   if (certs && count)
 322   {
 323     while (count > 0)
 324     {
 325       httpAddCredential(*credentials, certs->data, certs->size);
 326       certs ++;
 327       count --;
 328     }
 329   }
 330
 331   return (0);
 332 }
 333
 334
 335 /*
 336  * '_httpCreateCredentials()' - Create credentials in the internal format.
 337  */
 338
 339 http_tls_credentials_t                  /* O - Internal credentials */
 340 _httpCreateCredentials(
 341     cups_array_t *credentials)          /* I - Array of credentials */
 342 {
 343   (void)credentials;
 344
 345   return (NULL);
 346 }
 347
 348
 349 /*
 350  * '_httpFreeCredentials()' - Free internal credentials.
 351  */
 352
 353 void
 354 _httpFreeCredentials(
 355     http_tls_credentials_t credentials) /* I - Internal credentials */
 356 {
 357   (void)credentials;
 358 }
 359
 360
 361 /*
 362  * 'httpCredentialsAreValidForName()' - Return whether the credentials are valid for the given name.
 363  *
 364  * @since CUPS 2.0/OS 10.10@
 365  */
 366
 367 int                                     /* O - 1 if valid, 0 otherwise */
 368 httpCredentialsAreValidForName(
 369     cups_array_t *credentials,          /* I - Credentials */
 370     const char   *common_name)          /* I - Name to check */
 371 {
 372   gnutls_x509_crt_t     cert;           /* Certificate */
 373   int                   result = 0;     /* Result */
 374
 375
 376   cert = http_gnutls_create_credential((http_credential_t *)cupsArrayFirst(credentials));
 377   if (cert)
 378   {
 379     result = gnutls_x509_crt_check_hostname(cert, common_name) != 0;
 380
 381     if (result)
 382     {
 383       int               i,              /* Looping var */
 384                         count;          /* Number of revoked certificates */
 385       unsigned char     cserial[1024],  /* Certificate serial number */
 386                         rserial[1024];  /* Revoked serial number */
 387       size_t            cserial_size,   /* Size of cert serial number */
 388                         rserial_size;   /* Size of revoked serial number */
 389
 390       _cupsMutexLock(&tls_mutex);
 391
 392       count = gnutls_x509_crl_get_crt_count(tls_crl);
 393
 394       if (count > 0)
 395       {
 396         cserial_size = sizeof(cserial);
 397         gnutls_x509_crt_get_serial(cert, cserial, &cserial_size);
 398
 399         for (i = 0; i < count; i ++)
 400         {
 401           rserial_size = sizeof(rserial);
 402           if (!gnutls_x509_crl_get_crt_serial(tls_crl, (unsigned)i, rserial, &rserial_size, NULL) && cserial_size == rserial_size && !memcmp(cserial, rserial, rserial_size))
 403           {
 404             result = 0;
 405             break;
 406           }
 407         }
 408       }
 409
 410       _cupsMutexUnlock(&tls_mutex);
 411     }
 412
 413     gnutls_x509_crt_deinit(cert);
 414   }
 415
 416   return (result);
 417 }
 418
 419
 420 /*
 421  * 'httpCredentialsGetTrust()' - Return the trust of credentials.
 422  *
 423  * @since CUPS 2.0/OS 10.10@
 424  */
 425
 426 http_trust_t                            /* O - Level of trust */
 427 httpCredentialsGetTrust(
 428     cups_array_t *credentials,          /* I - Credentials */
 429     const char   *common_name)          /* I - Common name for trust lookup */
 430 {
 431   http_trust_t          trust = HTTP_TRUST_OK;
 432                                         /* Trusted? */
 433   gnutls_x509_crt_t     cert;           /* Certificate */
 434   cups_array_t          *tcreds = NULL; /* Trusted credentials */
 435   _cups_globals_t       *cg = _cupsGlobals();
 436                                         /* Per-thread globals */
 437
 438
 439   if (!common_name)
 440   {
 441     _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("No common name specified."), 1);
 442     return (HTTP_TRUST_UNKNOWN);
 443   }
 444
 445   if ((cert = http_gnutls_create_credential((http_credential_t *)cupsArrayFirst(credentials))) == NULL)
 446   {
 447     _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("Unable to create credentials from array."), 1);
 448     return (HTTP_TRUST_UNKNOWN);
 449   }
 450
 451   if (cg->any_root < 0)
 452   {
 453     _cupsSetDefaults();
 454     http_gnutls_load_crl();
 455   }
 456
 457  /*
 458   * Look this common name up in the default keychains...
 459   */
 460
 461   httpLoadCredentials(NULL, &tcreds, common_name);
 462
 463   if (tcreds)
 464   {
 465     char        credentials_str[1024],  /* String for incoming credentials */
 466                 tcreds_str[1024];       /* String for saved credentials */
 467
 468     httpCredentialsString(credentials, credentials_str, sizeof(credentials_str));
 469     httpCredentialsString(tcreds, tcreds_str, sizeof(tcreds_str));
 470
 471     if (strcmp(credentials_str, tcreds_str))
 472     {
 473      /*
 474       * Credentials don't match, let's look at the expiration date of the new
 475       * credentials and allow if the new ones have a later expiration...
 476       */
 477
 478       if (!cg->trust_first)
 479       {
 480        /*
 481         * Do not trust certificates on first use...
 482         */
 483
 484         _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("Trust on first use is disabled."), 1);
 485
 486         trust = HTTP_TRUST_INVALID;
 487       }
 488       else if (httpCredentialsGetExpiration(credentials) <= httpCredentialsGetExpiration(tcreds))
 489       {
 490        /*
 491         * The new credentials are not newly issued...
 492         */
 493
 494         _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("New credentials are older than stored credentials."), 1);
 495
 496         trust = HTTP_TRUST_INVALID;
 497       }
 498       else if (!httpCredentialsAreValidForName(credentials, common_name))
 499       {
 500        /*
 501         * The common name does not match the issued certificate...
 502         */
 503
 504         _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("New credentials are not valid for name."), 1);
 505
 506         trust = HTTP_TRUST_INVALID;
 507       }
 508       else if (httpCredentialsGetExpiration(tcreds) < time(NULL))
 509       {
 510        /*
 511         * Save the renewed credentials...
 512         */
 513
 514         trust = HTTP_TRUST_RENEWED;
 515
 516         httpSaveCredentials(NULL, credentials, common_name);
 517       }
 518     }
 519
 520     httpFreeCredentials(tcreds);
 521   }
 522   else if (cg->validate_certs && !httpCredentialsAreValidForName(credentials, common_name))
 523   {
 524     _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("No stored credentials, not valid for name."), 1);
 525     trust = HTTP_TRUST_INVALID;
 526   }
 527   else if (!cg->trust_first)
 528   {
 529    /*
 530     * See if we have a site CA certificate we can compare...
 531     */
 532
 533     if (!httpLoadCredentials(NULL, &tcreds, "site"))
 534     {
 535       if (cupsArrayCount(credentials) != (cupsArrayCount(tcreds) + 1))
 536       {
 537        /*
 538         * Certificate isn't directly generated from the CA cert...
 539         */
 540
 541         trust = HTTP_TRUST_INVALID;
 542       }
 543       else
 544       {
 545        /*
 546         * Do a tail comparison of the two certificates...
 547         */
 548
 549         http_credential_t       *a, *b;         /* Certificates */
 550
 551         for (a = (http_credential_t *)cupsArrayFirst(tcreds), b = (http_credential_t *)cupsArrayIndex(credentials, 1);
 552              a && b;
 553              a = (http_credential_t *)cupsArrayNext(tcreds), b = (http_credential_t *)cupsArrayNext(credentials))
 554           if (a->datalen != b->datalen || memcmp(a->data, b->data, a->datalen))
 555             break;
 556
 557         if (a || b)
 558           trust = HTTP_TRUST_INVALID;
 559       }
 560
 561       if (trust != HTTP_TRUST_OK)
 562         _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("Credentials do not validate against site CA certificate."), 1);
 563     }
 564     else
 565     {
 566       _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("Trust on first use is disabled."), 1);
 567       trust = HTTP_TRUST_INVALID;
 568     }
 569   }
 570
 571   if (trust == HTTP_TRUST_OK && !cg->expired_certs)
 572   {
 573     time_t      curtime;                /* Current date/time */
 574
 575     time(&curtime);
 576     if (curtime < gnutls_x509_crt_get_activation_time(cert) ||
 577         curtime > gnutls_x509_crt_get_expiration_time(cert))
 578     {
 579       _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("Credentials have expired."), 1);
 580       trust = HTTP_TRUST_EXPIRED;
 581     }
 582   }
 583
 584   if (trust == HTTP_TRUST_OK && !cg->any_root && cupsArrayCount(credentials) == 1)
 585   {
 586     _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("Self-signed credentials are blocked."), 1);
 587     trust = HTTP_TRUST_INVALID;
 588   }
 589
 590   gnutls_x509_crt_deinit(cert);
 591
 592   return (trust);
 593 }
 594
 595
 596 /*
 597  * 'httpCredentialsGetExpiration()' - Return the expiration date of the credentials.
 598  *
 599  * @since CUPS 2.0/OS 10.10@
 600  */
 601
 602 time_t                                  /* O - Expiration date of credentials */
 603 httpCredentialsGetExpiration(
 604     cups_array_t *credentials)          /* I - Credentials */
 605 {
 606   gnutls_x509_crt_t     cert;           /* Certificate */
 607   time_t                result = 0;     /* Result */
 608
 609
 610   cert = http_gnutls_create_credential((http_credential_t *)cupsArrayFirst(credentials));
 611   if (cert)
 612   {
 613     result = gnutls_x509_crt_get_expiration_time(cert);
 614     gnutls_x509_crt_deinit(cert);
 615   }
 616
 617   return (result);
 618 }
 619
 620
 621 /*
 622  * 'httpCredentialsString()' - Return a string representing the credentials.
 623  *
 624  * @since CUPS 2.0/OS 10.10@
 625  */
 626
 627 size_t                                  /* O - Total size of credentials string */
 628 httpCredentialsString(
 629     cups_array_t *credentials,          /* I - Credentials */
 630     char         *buffer,               /* I - Buffer or @code NULL@ */
 631     size_t       bufsize)               /* I - Size of buffer */
 632 {
 633   http_credential_t     *first;         /* First certificate */
 634   gnutls_x509_crt_t     cert;           /* Certificate */
 635
 636
 637   DEBUG_printf(("httpCredentialsString(credentials=%p, buffer=%p, bufsize=" CUPS_LLFMT ")", credentials, buffer, CUPS_LLCAST bufsize));
 638
 639   if (!buffer)
 640     return (0);
 641
 642   if (buffer && bufsize > 0)
 643     *buffer = '\0';
 644
 645   if ((first = (http_credential_t *)cupsArrayFirst(credentials)) != NULL &&
 646       (cert = http_gnutls_create_credential(first)) != NULL)
 647   {
 648     char                name[256];      /* Common name associated with cert */
 649     size_t              namelen;        /* Length of name */
 650     time_t              expiration;     /* Expiration date of cert */
 651     _cups_md5_state_t   md5_state;      /* MD5 state */
 652     unsigned char       md5_digest[16]; /* MD5 result */
 653
 654     namelen = sizeof(name) - 1;
 655     if (gnutls_x509_crt_get_dn_by_oid(cert, GNUTLS_OID_X520_COMMON_NAME, 0, 0, name, &namelen) >= 0)
 656       name[namelen] = '\0';
 657     else
 658       strlcpy(name, "unknown", sizeof(name));
 659
 660     expiration = gnutls_x509_crt_get_expiration_time(cert);
 661
 662     _cupsMD5Init(&md5_state);
 663     _cupsMD5Append(&md5_state, first->data, (int)first->datalen);
 664     _cupsMD5Finish(&md5_state, md5_digest);
 665
 666     snprintf(buffer, bufsize, "%s / %s / %02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X", name, httpGetDateString(expiration), md5_digest[0], md5_digest[1], md5_digest[2], md5_digest[3], md5_digest[4], md5_digest[5], md5_digest[6], md5_digest[7], md5_digest[8], md5_digest[9], md5_digest[10], md5_digest[11], md5_digest[12], md5_digest[13], md5_digest[14], md5_digest[15]);
 667
 668     gnutls_x509_crt_deinit(cert);
 669   }
 670
 671   DEBUG_printf(("1httpCredentialsString: Returning \"%s\".", buffer));
 672
 673   return (strlen(buffer));
 674 }
 675
 676
 677 /*
 678  * 'httpLoadCredentials()' - Load X.509 credentials from a keychain file.
 679  *
 680  * @since CUPS 2.0/OS 10.10@
 681  */
 682
 683 int                                     /* O - 0 on success, -1 on error */
 684 httpLoadCredentials(
 685     const char   *path,                 /* I  - Keychain/PKCS#12 path */
 686     cups_array_t **credentials,         /* IO - Credentials */
 687     const char   *common_name)          /* I  - Common name for credentials */
 688 {
 689   cups_file_t           *fp;            /* Certificate file */
 690   char                  filename[1024], /* filename.crt */
 691                         temp[1024],     /* Temporary string */
 692                         line[256];      /* Base64-encoded line */
 693   unsigned char         *data = NULL;   /* Buffer for cert data */
 694   size_t                alloc_data = 0, /* Bytes allocated */
 695                         num_data = 0;   /* Bytes used */
 696   int                   decoded;        /* Bytes decoded */
 697   int                   in_certificate = 0;
 698                                         /* In a certificate? */
 699
 700
 701   if (!credentials || !common_name)
 702     return (-1);
 703
 704   if (!path)
 705     path = http_gnutls_default_path(temp, sizeof(temp));
 706   if (!path)
 707     return (-1);
 708
 709   http_gnutls_make_path(filename, sizeof(filename), path, common_name, "crt");
 710
 711   if ((fp = cupsFileOpen(filename, "r")) == NULL)
 712     return (-1);
 713
 714   while (cupsFileGets(fp, line, sizeof(line)))
 715   {
 716     if (!strcmp(line, "-----BEGIN CERTIFICATE-----"))
 717     {
 718       if (in_certificate)
 719       {
 720        /*
 721         * Missing END CERTIFICATE...
 722         */
 723
 724         httpFreeCredentials(*credentials);
 725         *credentials = NULL;
 726         break;
 727       }
 728
 729       in_certificate = 1;
 730     }
 731     else if (!strcmp(line, "-----END CERTIFICATE-----"))
 732     {
 733       if (!in_certificate || !num_data)
 734       {
 735        /*
 736         * Missing data...
 737         */
 738
 739         httpFreeCredentials(*credentials);
 740         *credentials = NULL;
 741         break;
 742       }
 743
 744       if (!*credentials)
 745         *credentials = cupsArrayNew(NULL, NULL);
 746
 747       if (httpAddCredential(*credentials, data, num_data))
 748       {
 749         httpFreeCredentials(*credentials);
 750         *credentials = NULL;
 751         break;
 752       }
 753
 754       num_data       = 0;
 755       in_certificate = 0;
 756     }
 757     else if (in_certificate)
 758     {
 759       if (alloc_data == 0)
 760       {
 761         data       = malloc(2048);
 762         alloc_data = 2048;
 763
 764         if (!data)
 765           break;
 766       }
 767       else if ((num_data + strlen(line)) >= alloc_data)
 768       {
 769         unsigned char *tdata = realloc(data, alloc_data + 1024);
 770                                         /* Expanded buffer */
 771
 772         if (!tdata)
 773         {
 774           httpFreeCredentials(*credentials);
 775           *credentials = NULL;
 776           break;
 777         }
 778
 779         data       = tdata;
 780         alloc_data += 1024;
 781       }
 782
 783       decoded = alloc_data - num_data;
 784       httpDecode64_2((char *)data + num_data, &decoded, line);
 785       num_data += (size_t)decoded;
 786     }
 787   }
 788
 789   cupsFileClose(fp);
 790
 791   if (in_certificate)
 792   {
 793    /*
 794     * Missing END CERTIFICATE...
 795     */
 796
 797     httpFreeCredentials(*credentials);
 798     *credentials = NULL;
 799   }
 800
 801   if (data)
 802     free(data);
 803
 804   return (*credentials ? 0 : -1);
 805 }
 806
 807
 808 /*
 809  * 'httpSaveCredentials()' - Save X.509 credentials to a keychain file.
 810  *
 811  * @since CUPS 2.0/OS 10.10@
 812  */
 813
 814 int                                     /* O - -1 on error, 0 on success */
 815 httpSaveCredentials(
 816     const char   *path,                 /* I - Keychain/PKCS#12 path */
 817     cups_array_t *credentials,          /* I - Credentials */
 818     const char   *common_name)          /* I - Common name for credentials */
 819 {
 820   cups_file_t           *fp;            /* Certificate file */
 821   char                  filename[1024], /* filename.crt */
 822                         nfilename[1024],/* filename.crt.N */
 823                         temp[1024],     /* Temporary string */
 824                         line[256];      /* Base64-encoded line */
 825   const unsigned char   *ptr;           /* Pointer into certificate */
 826   ssize_t               remaining;      /* Bytes left */
 827   http_credential_t     *cred;          /* Current credential */
 828
 829
 830   if (!credentials || !common_name)
 831     return (-1);
 832
 833   if (!path)
 834     path = http_gnutls_default_path(temp, sizeof(temp));
 835   if (!path)
 836     return (-1);
 837
 838   http_gnutls_make_path(filename, sizeof(filename), path, common_name, "crt");
 839   snprintf(nfilename, sizeof(nfilename), "%s.N", filename);
 840
 841   if ((fp = cupsFileOpen(nfilename, "w")) == NULL)
 842     return (-1);
 843
 844   fchmod(cupsFileNumber(fp), 0600);
 845
 846   for (cred = (http_credential_t *)cupsArrayFirst(credentials);
 847        cred;
 848        cred = (http_credential_t *)cupsArrayNext(credentials))
 849   {
 850     cupsFilePuts(fp, "-----BEGIN CERTIFICATE-----\n");
 851     for (ptr = cred->data, remaining = (ssize_t)cred->datalen; remaining > 0; remaining -= 45, ptr += 45)
 852     {
 853       httpEncode64_2(line, sizeof(line), (char *)ptr, remaining > 45 ? 45 : remaining);
 854       cupsFilePrintf(fp, "%s\n", line);
 855     }
 856     cupsFilePuts(fp, "-----END CERTIFICATE-----\n");
 857   }
 858
 859   cupsFileClose(fp);
 860
 861   return (rename(nfilename, filename));
 862 }
 863
 864
 865 /*
 866  * 'http_gnutls_create_credential()' - Create a single credential in the internal format.
 867  */
 868
 869 static gnutls_x509_crt_t                        /* O - Certificate */
 870 http_gnutls_create_credential(
 871     http_credential_t *credential)              /* I - Credential */
 872 {
 873   int                   result;                 /* Result from GNU TLS */
 874   gnutls_x509_crt_t     cert;                   /* Certificate */
 875   gnutls_datum_t        datum;                  /* Data record */
 876
 877
 878   DEBUG_printf(("3http_gnutls_create_credential(credential=%p)", credential));
 879
 880   if (!credential)
 881     return (NULL);
 882
 883   if ((result = gnutls_x509_crt_init(&cert)) < 0)
 884   {
 885     DEBUG_printf(("4http_gnutls_create_credential: init error: %s", gnutls_strerror(result)));
 886     return (NULL);
 887   }
 888
 889   datum.data = credential->data;
 890   datum.size = credential->datalen;
 891
 892   if ((result = gnutls_x509_crt_import(cert, &datum, GNUTLS_X509_FMT_DER)) < 0)
 893   {
 894     DEBUG_printf(("4http_gnutls_create_credential: import error: %s", gnutls_strerror(result)));
 895
 896     gnutls_x509_crt_deinit(cert);
 897     return (NULL);
 898   }
 899
 900   return (cert);
 901 }
 902
 903
 904 /*
 905  * 'http_gnutls_default_path()' - Get the default credential store path.
 906  */
 907
 908 static const char *                     /* O - Path or NULL on error */
 909 http_gnutls_default_path(char   *buffer,/* I - Path buffer */
 910                          size_t bufsize)/* I - Size of path buffer */
 911 {
 912   const char *home = getenv("HOME");    /* HOME environment variable */
 913
 914
 915   if (getuid() && home)
 916   {
 917     snprintf(buffer, bufsize, "%s/.cups", home);
 918     if (access(buffer, 0))
 919     {
 920       DEBUG_printf(("1http_gnutls_default_path: Making directory \"%s\".", buffer));
 921       if (mkdir(buffer, 0700))
 922       {
 923         DEBUG_printf(("1http_gnutls_default_path: Failed to make directory: %s", strerror(errno)));
 924         return (NULL);
 925       }
 926     }
 927
 928     snprintf(buffer, bufsize, "%s/.cups/ssl", home);
 929     if (access(buffer, 0))
 930     {
 931       DEBUG_printf(("1http_gnutls_default_path: Making directory \"%s\".", buffer));
 932       if (mkdir(buffer, 0700))
 933       {
 934         DEBUG_printf(("1http_gnutls_default_path: Failed to make directory: %s", strerror(errno)));
 935         return (NULL);
 936       }
 937     }
 938   }
 939   else
 940     strlcpy(buffer, CUPS_SERVERROOT "/ssl", bufsize);
 941
 942   DEBUG_printf(("1http_gnutls_default_path: Using default path \"%s\".", buffer));
 943
 944   return (buffer);
 945 }
 946
 947
 948 /*
 949  * 'http_gnutls_load_crl()' - Load the certificate revocation list, if any.
 950  */
 951
 952 static void
 953 http_gnutls_load_crl(void)
 954 {
 955   _cupsMutexLock(&tls_mutex);
 956
 957   if (!gnutls_x509_crl_init(&tls_crl))
 958   {
 959     cups_file_t         *fp;            /* CRL file */
 960     char                filename[1024], /* site.crl */
 961                         line[256];      /* Base64-encoded line */
 962     unsigned char       *data = NULL;   /* Buffer for cert data */
 963     size_t              alloc_data = 0, /* Bytes allocated */
 964                         num_data = 0;   /* Bytes used */
 965     int                 decoded;        /* Bytes decoded */
 966     gnutls_datum_t      datum;          /* Data record */
 967
 968
 969     http_gnutls_make_path(filename, sizeof(filename), CUPS_SERVERROOT, "site", "crl");
 970
 971     if ((fp = cupsFileOpen(filename, "r")) != NULL)
 972     {
 973       while (cupsFileGets(fp, line, sizeof(line)))
 974       {
 975         if (!strcmp(line, "-----BEGIN X509 CRL-----"))
 976         {
 977           if (num_data)
 978           {
 979            /*
 980             * Missing END X509 CRL...
 981             */
 982
 983             break;
 984           }
 985         }
 986         else if (!strcmp(line, "-----END X509 CRL-----"))
 987         {
 988           if (!num_data)
 989           {
 990            /*
 991             * Missing data...
 992             */
 993
 994             break;
 995           }
 996
 997           datum.data = data;
 998           datum.size = num_data;
 999
1000           gnutls_x509_crl_import(tls_crl, &datum, GNUTLS_X509_FMT_PEM);
1001
1002           num_data = 0;
1003         }
1004         else
1005         {
1006           if (alloc_data == 0)
1007           {
1008             data       = malloc(2048);
1009             alloc_data = 2048;
1010
1011             if (!data)
1012               break;
1013           }
1014           else if ((num_data + strlen(line)) >= alloc_data)
1015           {
1016             unsigned char *tdata = realloc(data, alloc_data + 1024);
1017                                             /* Expanded buffer */
1018
1019             if (!tdata)
1020               break;
1021
1022             data       = tdata;
1023             alloc_data += 1024;
1024           }
1025
1026           decoded = alloc_data - num_data;
1027           httpDecode64_2((char *)data + num_data, &decoded, line);
1028           num_data += (size_t)decoded;
1029         }
1030       }
1031
1032       cupsFileClose(fp);
1033
1034       if (data)
1035         free(data);
1036     }
1037   }
1038
1039   _cupsMutexUnlock(&tls_mutex);
1040 }
1041
1042
1043 /*
1044  * 'http_gnutls_make_path()' - Format a filename for a certificate or key file.
1045  */
1046
1047 static const char *                     /* O - Filename */
1048 http_gnutls_make_path(
1049     char       *buffer,                 /* I - Filename buffer */
1050     size_t     bufsize,                 /* I - Size of buffer */
1051     const char *dirname,                /* I - Directory */
1052     const char *filename,               /* I - Filename (usually hostname) */
1053     const char *ext)                    /* I - Extension */
1054 {
1055   char  *bufptr,                        /* Pointer into buffer */
1056         *bufend = buffer + bufsize - 1; /* End of buffer */
1057
1058
1059   snprintf(buffer, bufsize, "%s/", dirname);
1060   bufptr = buffer + strlen(buffer);
1061
1062   while (*filename && bufptr < bufend)
1063   {
1064     if (_cups_isalnum(*filename) || *filename == '-' || *filename == '.')
1065       *bufptr++ = *filename;
1066     else
1067       *bufptr++ = '_';
1068
1069     filename ++;
1070   }
1071
1072   if (bufptr < bufend)
1073     *bufptr++ = '.';
1074
1075   strlcpy(bufptr, ext, (size_t)(bufend - bufptr + 1));
1076
1077   return (buffer);
1078 }
1079
1080
1081 /*
1082  * 'http_gnutls_read()' - Read function for the GNU TLS library.
1083  */
1084
1085 static ssize_t                          /* O - Number of bytes read or -1 on error */
1086 http_gnutls_read(
1087     gnutls_transport_ptr_t ptr,         /* I - Connection to server */
1088     void                   *data,       /* I - Buffer */
1089     size_t                 length)      /* I - Number of bytes to read */
1090 {
1091   http_t        *http;                  /* HTTP connection */
1092   ssize_t       bytes;                  /* Bytes read */
1093
1094
1095   DEBUG_printf(("6http_gnutls_read(ptr=%p, data=%p, length=%d)", ptr, data, (int)length));
1096
1097   http = (http_t *)ptr;
1098
1099   if (!http->blocking)
1100   {
1101    /*
1102     * Make sure we have data before we read...
1103     */
1104
1105     while (!_httpWait(http, http->wait_value, 0))
1106     {
1107       if (http->timeout_cb && (*http->timeout_cb)(http, http->timeout_data))
1108         continue;
1109
1110       http->error = ETIMEDOUT;
1111       return (-1);
1112     }
1113   }
1114
1115   bytes = recv(http->fd, data, length, 0);
1116   DEBUG_printf(("6http_gnutls_read: bytes=%d", (int)bytes));
1117   return (bytes);
1118 }
1119
1120
1121 /*
1122  * 'http_gnutls_write()' - Write function for the GNU TLS library.
1123  */
1124
1125 static ssize_t                          /* O - Number of bytes written or -1 on error */
1126 http_gnutls_write(
1127     gnutls_transport_ptr_t ptr,         /* I - Connection to server */
1128     const void             *data,       /* I - Data buffer */
1129     size_t                 length)      /* I - Number of bytes to write */
1130 {
1131   ssize_t bytes;                        /* Bytes written */
1132
1133
1134   DEBUG_printf(("6http_gnutls_write(ptr=%p, data=%p, length=%d)", ptr, data,
1135                 (int)length));
1136   bytes = send(((http_t *)ptr)->fd, data, length, 0);
1137   DEBUG_printf(("http_gnutls_write: bytes=%d", (int)bytes));
1138
1139   return (bytes);
1140 }
1141
1142
1143 /*
1144  * '_httpTLSInitialize()' - Initialize the TLS stack.
1145  */
1146
1147 void
1148 _httpTLSInitialize(void)
1149 {
1150  /*
1151   * Initialize GNU TLS...
1152   */
1153
1154   gnutls_global_init();
1155 }
1156
1157
1158 /*
1159  * '_httpTLSPending()' - Return the number of pending TLS-encrypted bytes.
1160  */
1161
1162 size_t                                  /* O - Bytes available */
1163 _httpTLSPending(http_t *http)           /* I - HTTP connection */
1164 {
1165   return (gnutls_record_check_pending(http->tls));
1166 }
1167
1168
1169 /*
1170  * '_httpTLSRead()' - Read from a SSL/TLS connection.
1171  */
1172
1173 int                                     /* O - Bytes read */
1174 _httpTLSRead(http_t *http,              /* I - Connection to server */
1175              char   *buf,               /* I - Buffer to store data */
1176              int    len)                /* I - Length of buffer */
1177 {
1178   ssize_t       result;                 /* Return value */
1179
1180
1181   result = gnutls_record_recv(http->tls, buf, (size_t)len);
1182
1183   if (result < 0 && !errno)
1184   {
1185    /*
1186     * Convert GNU TLS error to errno value...
1187     */
1188
1189     switch (result)
1190     {
1191       case GNUTLS_E_INTERRUPTED :
1192           errno = EINTR;
1193           break;
1194
1195       case GNUTLS_E_AGAIN :
1196           errno = EAGAIN;
1197           break;
1198
1199       default :
1200           errno = EPIPE;
1201           break;
1202     }
1203
1204     result = -1;
1205   }
1206
1207   return ((int)result);
1208 }
1209
1210
1211 /*
1212  * '_httpTLSSetCredentials()' - Set the TLS credentials.
1213  */
1214
1215 int                                     /* O - Status of connection */
1216 _httpTLSSetCredentials(http_t *http)    /* I - Connection to server */
1217 {
1218   (void)http;
1219
1220   return (0);
1221 }
1222
1223
1224 /*
1225  * '_httpTLSSetOptions()' - Set TLS protocol and cipher suite options.
1226  */
1227
1228 void
1229 _httpTLSSetOptions(int options)         /* I - Options */
1230 {
1231   if (!(options & _HTTP_TLS_SET_DEFAULT) || tls_options < 0)
1232   {
1233     tls_options     = options;
1234     tls_min_version = min_version;
1235     tls_max_version = max_version;
1236   }
1237 }
1238
1239
1240 /*
1241  * '_httpTLSStart()' - Set up SSL/TLS support on a connection.
1242  */
1243
1244 int                                     /* O - 0 on success, -1 on failure */
1245 _httpTLSStart(http_t *http)             /* I - Connection to server */
1246 {
1247   char                  hostname[256],  /* Hostname */
1248                         *hostptr;       /* Pointer into hostname */
1249   int                   status;         /* Status of handshake */
1250   gnutls_certificate_credentials_t *credentials;
1251                                         /* TLS credentials */
1252   char                  priority_string[2048];
1253                                         /* Priority string */
1254   int                   version;        /* Current version */
1255   static const char * const versions[] =/* SSL/TLS versions */
1256   {
1257     "VERS-SSL3.0",
1258     "VERS-TLS1.0",
1259     "VERS-TLS1.1",
1260     "VERS-TLS1.2",
1261     "VERS-TLS1.3",
1262     "VERS-TLS-ALL"
1263   };
1264
1265
1266   DEBUG_printf(("3_httpTLSStart(http=%p)", http));
1267
1268   if (tls_options < 0)
1269   {
1270     DEBUG_puts("4_httpTLSStart: Setting defaults.");
1271     _cupsSetDefaults();
1272     DEBUG_printf(("4_httpTLSStart: tls_options=%x", tls_options));
1273   }
1274
1275   if (http->mode == _HTTP_MODE_SERVER && !tls_keypath)
1276   {
1277     DEBUG_puts("4_httpTLSStart: cupsSetServerCredentials not called.");
1278     http->error  = errno = EINVAL;
1279     http->status = HTTP_STATUS_ERROR;
1280     _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("Server credentials not set."), 1);
1281
1282     return (-1);
1283   }
1284
1285   credentials = (gnutls_certificate_credentials_t *)
1286                     malloc(sizeof(gnutls_certificate_credentials_t));
1287   if (credentials == NULL)
1288   {
1289     DEBUG_printf(("8_httpStartTLS: Unable to allocate credentials: %s",
1290                   strerror(errno)));
1291     http->error  = errno;
1292     http->status = HTTP_STATUS_ERROR;
1293     _cupsSetHTTPError(HTTP_STATUS_ERROR);
1294
1295     return (-1);
1296   }
1297
1298   gnutls_certificate_allocate_credentials(credentials);
1299   status = gnutls_init(&http->tls, http->mode == _HTTP_MODE_CLIENT ? GNUTLS_CLIENT : GNUTLS_SERVER);
1300   if (!status)
1301     status = gnutls_set_default_priority(http->tls);
1302
1303   if (status)
1304   {
1305     http->error  = EIO;
1306     http->status = HTTP_STATUS_ERROR;
1307
1308     DEBUG_printf(("4_httpTLSStart: Unable to initialize common TLS parameters: %s", gnutls_strerror(status)));
1309     _cupsSetError(IPP_STATUS_ERROR_CUPS_PKI, gnutls_strerror(status), 0);
1310
1311     gnutls_deinit(http->tls);
1312     gnutls_certificate_free_credentials(*credentials);
1313     free(credentials);
1314     http->tls = NULL;
1315
1316     return (-1);
1317   }
1318
1319   if (http->mode == _HTTP_MODE_CLIENT)
1320   {
1321    /*
1322     * Client: get the hostname to use for TLS...
1323     */
1324
1325     if (httpAddrLocalhost(http->hostaddr))
1326     {
1327       strlcpy(hostname, "localhost", sizeof(hostname));
1328     }
1329     else
1330     {
1331      /*
1332       * Otherwise make sure the hostname we have does not end in a trailing dot.
1333       */
1334
1335       strlcpy(hostname, http->hostname, sizeof(hostname));
1336       if ((hostptr = hostname + strlen(hostname) - 1) >= hostname &&
1337           *hostptr == '.')
1338         *hostptr = '\0';
1339     }
1340
1341     status = gnutls_server_name_set(http->tls, GNUTLS_NAME_DNS, hostname, strlen(hostname));
1342   }
1343   else
1344   {
1345    /*
1346     * Server: get certificate and private key...
1347     */
1348
1349     char        crtfile[1024],          /* Certificate file */
1350                 keyfile[1024];          /* Private key file */
1351     int         have_creds = 0;         /* Have credentials? */
1352
1353     if (http->fields[HTTP_FIELD_HOST][0])
1354     {
1355      /*
1356       * Use hostname for TLS upgrade...
1357       */
1358
1359       strlcpy(hostname, http->fields[HTTP_FIELD_HOST], sizeof(hostname));
1360     }
1361     else
1362     {
1363      /*
1364       * Resolve hostname from connection address...
1365       */
1366
1367       http_addr_t       addr;           /* Connection address */
1368       socklen_t         addrlen;        /* Length of address */
1369
1370       addrlen = sizeof(addr);
1371       if (getsockname(http->fd, (struct sockaddr *)&addr, &addrlen))
1372       {
1373         DEBUG_printf(("4_httpTLSStart: Unable to get socket address: %s", strerror(errno)));
1374         hostname[0] = '\0';
1375       }
1376       else if (httpAddrLocalhost(&addr))
1377         hostname[0] = '\0';
1378       else
1379       {
1380         httpAddrLookup(&addr, hostname, sizeof(hostname));
1381         DEBUG_printf(("4_httpTLSStart: Resolved socket address to \"%s\".", hostname));
1382       }
1383     }
1384
1385     if (isdigit(hostname[0] & 255) || hostname[0] == '[')
1386       hostname[0] = '\0';               /* Don't allow numeric addresses */
1387
1388     if (hostname[0])
1389     {
1390      /*
1391       * First look in the CUPS keystore...
1392       */
1393
1394       http_gnutls_make_path(crtfile, sizeof(crtfile), tls_keypath, hostname, "crt");
1395       http_gnutls_make_path(keyfile, sizeof(keyfile), tls_keypath, hostname, "key");
1396
1397       if (access(crtfile, R_OK) || access(keyfile, R_OK))
1398       {
1399        /*
1400         * No CUPS-managed certs, look for CA certs...
1401         */
1402
1403         char cacrtfile[1024], cakeyfile[1024];  /* CA cert files */
1404
1405         snprintf(cacrtfile, sizeof(cacrtfile), "/etc/letsencrypt/live/%s/fullchain.pem", hostname);
1406         snprintf(cakeyfile, sizeof(cakeyfile), "/etc/letsencrypt/live/%s/privkey.pem", hostname);
1407
1408         if ((access(cacrtfile, R_OK) || access(cakeyfile, R_OK)) && (hostptr = strchr(hostname, '.')) != NULL)
1409         {
1410          /*
1411           * Try just domain name...
1412           */
1413
1414           hostptr ++;
1415           if (strchr(hostptr, '.'))
1416           {
1417             snprintf(cacrtfile, sizeof(cacrtfile), "/etc/letsencrypt/live/%s/fullchain.pem", hostptr);
1418             snprintf(cakeyfile, sizeof(cakeyfile), "/etc/letsencrypt/live/%s/privkey.pem", hostptr);
1419           }
1420         }
1421
1422         if (!access(cacrtfile, R_OK) && !access(cakeyfile, R_OK))
1423         {
1424          /*
1425           * Use the CA certs...
1426           */
1427
1428           strlcpy(crtfile, cacrtfile, sizeof(crtfile));
1429           strlcpy(keyfile, cakeyfile, sizeof(keyfile));
1430         }
1431       }
1432
1433       have_creds = !access(crtfile, R_OK) && !access(keyfile, R_OK);
1434     }
1435     else if (tls_common_name)
1436     {
1437      /*
1438       * First look in the CUPS keystore...
1439       */
1440
1441       http_gnutls_make_path(crtfile, sizeof(crtfile), tls_keypath, tls_common_name, "crt");
1442       http_gnutls_make_path(keyfile, sizeof(keyfile), tls_keypath, tls_common_name, "key");
1443
1444       if (access(crtfile, R_OK) || access(keyfile, R_OK))
1445       {
1446        /*
1447         * No CUPS-managed certs, look for CA certs...
1448         */
1449
1450         char cacrtfile[1024], cakeyfile[1024];  /* CA cert files */
1451
1452         snprintf(cacrtfile, sizeof(cacrtfile), "/etc/letsencrypt/live/%s/fullchain.pem", tls_common_name);
1453         snprintf(cakeyfile, sizeof(cakeyfile), "/etc/letsencrypt/live/%s/privkey.pem", tls_common_name);
1454
1455         if ((access(cacrtfile, R_OK) || access(cakeyfile, R_OK)) && (hostptr = strchr(tls_common_name, '.')) != NULL)
1456         {
1457          /*
1458           * Try just domain name...
1459           */
1460
1461           hostptr ++;
1462           if (strchr(hostptr, '.'))
1463           {
1464             snprintf(cacrtfile, sizeof(cacrtfile), "/etc/letsencrypt/live/%s/fullchain.pem", hostptr);
1465             snprintf(cakeyfile, sizeof(cakeyfile), "/etc/letsencrypt/live/%s/privkey.pem", hostptr);
1466           }
1467         }
1468
1469         if (!access(cacrtfile, R_OK) && !access(cakeyfile, R_OK))
1470         {
1471          /*
1472           * Use the CA certs...
1473           */
1474
1475           strlcpy(crtfile, cacrtfile, sizeof(crtfile));
1476           strlcpy(keyfile, cakeyfile, sizeof(keyfile));
1477         }
1478       }
1479
1480       have_creds = !access(crtfile, R_OK) && !access(keyfile, R_OK);
1481     }
1482
1483     if (!have_creds && tls_auto_create && (hostname[0] || tls_common_name))
1484     {
1485       DEBUG_printf(("4_httpTLSStart: Auto-create credentials for \"%s\".", hostname[0] ? hostname : tls_common_name));
1486
1487       if (!cupsMakeServerCredentials(tls_keypath, hostname[0] ? hostname : tls_common_name, 0, NULL, time(NULL) + 365 * 86400))
1488       {
1489         DEBUG_puts("4_httpTLSStart: cupsMakeServerCredentials failed.");
1490         http->error  = errno = EINVAL;
1491         http->status = HTTP_STATUS_ERROR;
1492         _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("Unable to create server credentials."), 1);
1493
1494         return (-1);
1495       }
1496     }
1497
1498     DEBUG_printf(("4_httpTLSStart: Using certificate \"%s\" and private key \"%s\".", crtfile, keyfile));
1499
1500     if (!status)
1501       status = gnutls_certificate_set_x509_key_file(*credentials, crtfile, keyfile, GNUTLS_X509_FMT_PEM);
1502   }
1503
1504   if (!status)
1505     status = gnutls_credentials_set(http->tls, GNUTLS_CRD_CERTIFICATE, *credentials);
1506
1507   if (status)
1508   {
1509     http->error  = EIO;
1510     http->status = HTTP_STATUS_ERROR;
1511
1512     DEBUG_printf(("4_httpTLSStart: Unable to complete client/server setup: %s", gnutls_strerror(status)));
1513     _cupsSetError(IPP_STATUS_ERROR_CUPS_PKI, gnutls_strerror(status), 0);
1514
1515     gnutls_deinit(http->tls);
1516     gnutls_certificate_free_credentials(*credentials);
1517     free(credentials);
1518     http->tls = NULL;
1519
1520     return (-1);
1521   }
1522
1523   strlcpy(priority_string, "NORMAL", sizeof(priority_string));
1524
1525   if (tls_max_version < _HTTP_TLS_MAX)
1526   {
1527    /*
1528     * Require specific TLS versions...
1529     */
1530
1531     strlcat(priority_string, ":-VERS-TLS-ALL", sizeof(priority_string));
1532     for (version = tls_min_version; version <= tls_max_version; version ++)
1533     {
1534       strlcat(priority_string, ":+", sizeof(priority_string));
1535       strlcat(priority_string, versions[version], sizeof(priority_string));
1536     }
1537   }
1538   else if (tls_min_version == _HTTP_TLS_SSL3)
1539   {
1540    /*
1541     * Allow all versions of TLS and SSL/3.0...
1542     */
1543
1544     strlcat(priority_string, ":+VERS-TLS-ALL:+VERS-SSL3.0", sizeof(priority_string));
1545   }
1546   else
1547   {
1548    /*
1549     * Require a minimum version...
1550     */
1551
1552     strlcat(priority_string, ":+VERS-TLS-ALL", sizeof(priority_string));
1553     for (version = 0; version < tls_min_version; version ++)
1554     {
1555       strlcat(priority_string, ":-", sizeof(priority_string));
1556       strlcat(priority_string, versions[version], sizeof(priority_string));
1557     }
1558   }
1559
1560   if (tls_options & _HTTP_TLS_ALLOW_RC4)
1561     strlcat(priority_string, ":+ARCFOUR-128", sizeof(priority_string));
1562   else
1563     strlcat(priority_string, ":!ARCFOUR-128", sizeof(priority_string));
1564
1565   strlcat(priority_string, ":!ANON-DH", sizeof(priority_string));
1566
1567   if (tls_options & _HTTP_TLS_DENY_CBC)
1568     strlcat(priority_string, ":!AES-128-CBC:!AES-256-CBC:!CAMELLIA-128-CBC:!CAMELLIA-256-CBC:!3DES-CBC", sizeof(priority_string));
1569
1570 #ifdef HAVE_GNUTLS_PRIORITY_SET_DIRECT
1571   gnutls_priority_set_direct(http->tls, priority_string, NULL);
1572
1573 #else
1574   gnutls_priority_t priority;           /* Priority */
1575
1576   gnutls_priority_init(&priority, priority_string, NULL);
1577   gnutls_priority_set(http->tls, priority);
1578   gnutls_priority_deinit(priority);
1579 #endif /* HAVE_GNUTLS_PRIORITY_SET_DIRECT */
1580
1581   gnutls_transport_set_ptr(http->tls, (gnutls_transport_ptr_t)http);
1582   gnutls_transport_set_pull_function(http->tls, http_gnutls_read);
1583 #ifdef HAVE_GNUTLS_TRANSPORT_SET_PULL_TIMEOUT_FUNCTION
1584   gnutls_transport_set_pull_timeout_function(http->tls, (gnutls_pull_timeout_func)httpWait);
1585 #endif /* HAVE_GNUTLS_TRANSPORT_SET_PULL_TIMEOUT_FUNCTION */
1586   gnutls_transport_set_push_function(http->tls, http_gnutls_write);
1587
1588   while ((status = gnutls_handshake(http->tls)) != GNUTLS_E_SUCCESS)
1589   {
1590     DEBUG_printf(("5_httpStartTLS: gnutls_handshake returned %d (%s)",
1591                   status, gnutls_strerror(status)));
1592
1593     if (gnutls_error_is_fatal(status))
1594     {
1595       http->error  = EIO;
1596       http->status = HTTP_STATUS_ERROR;
1597
1598       _cupsSetError(IPP_STATUS_ERROR_CUPS_PKI, gnutls_strerror(status), 0);
1599
1600       gnutls_deinit(http->tls);
1601       gnutls_certificate_free_credentials(*credentials);
1602       free(credentials);
1603       http->tls = NULL;
1604
1605       return (-1);
1606     }
1607   }
1608
1609   http->tls_credentials = credentials;
1610
1611   return (0);
1612 }
1613
1614
1615 /*
1616  * '_httpTLSStop()' - Shut down SSL/TLS on a connection.
1617  */
1618
1619 void
1620 _httpTLSStop(http_t *http)              /* I - Connection to server */
1621 {
1622   int   error;                          /* Error code */
1623
1624
1625   error = gnutls_bye(http->tls, http->mode == _HTTP_MODE_CLIENT ? GNUTLS_SHUT_RDWR : GNUTLS_SHUT_WR);
1626   if (error != GNUTLS_E_SUCCESS)
1627     _cupsSetError(IPP_STATUS_ERROR_INTERNAL, gnutls_strerror(errno), 0);
1628
1629   gnutls_deinit(http->tls);
1630   http->tls = NULL;
1631
1632   if (http->tls_credentials)
1633   {
1634     gnutls_certificate_free_credentials(*(http->tls_credentials));
1635     free(http->tls_credentials);
1636     http->tls_credentials = NULL;
1637   }
1638 }
1639
1640
1641 /*
1642  * '_httpTLSWrite()' - Write to a SSL/TLS connection.
1643  */
1644
1645 int                                     /* O - Bytes written */
1646 _httpTLSWrite(http_t     *http,         /* I - Connection to server */
1647               const char *buf,          /* I - Buffer holding data */
1648               int        len)           /* I - Length of buffer */
1649 {
1650   ssize_t       result;                 /* Return value */
1651
1652
1653   DEBUG_printf(("2http_write_ssl(http=%p, buf=%p, len=%d)", http, buf, len));
1654
1655   result = gnutls_record_send(http->tls, buf, (size_t)len);
1656
1657   if (result < 0 && !errno)
1658   {
1659    /*
1660     * Convert GNU TLS error to errno value...
1661     */
1662
1663     switch (result)
1664     {
1665       case GNUTLS_E_INTERRUPTED :
1666           errno = EINTR;
1667           break;
1668
1669       case GNUTLS_E_AGAIN :
1670           errno = EAGAIN;
1671           break;
1672
1673       default :
1674           errno = EPIPE;
1675           break;
1676     }
1677
1678     result = -1;
1679   }
1680
1681   DEBUG_printf(("3http_write_ssl: Returning %d.", (int)result));
1682
1683   return ((int)result);
1684 }