cups/tls-gnutls.c

   1 /*
   2  * TLS support code for CUPS using GNU TLS.
   3  *
   4  * Copyright 2007-2016 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  * file is 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
  40
  41 /*
  42  * Local functions...
  43  */
  44
  45 static gnutls_x509_crt_t http_gnutls_create_credential(http_credential_t *credential);
  46 static const char       *http_gnutls_default_path(char *buffer, size_t bufsize);
  47 static void             http_gnutls_load_crl(void);
  48 static const char       *http_gnutls_make_path(char *buffer, size_t bufsize, const char *dirname, const char *filename, const char *ext);
  49 static ssize_t          http_gnutls_read(gnutls_transport_ptr_t ptr, void *data, size_t length);
  50 static ssize_t          http_gnutls_write(gnutls_transport_ptr_t ptr, const void *data, size_t length);
  51
  52
  53 /*
  54  * 'cupsMakeServerCredentials()' - Make a self-signed certificate and private key pair.
  55  *
  56  * @since CUPS 2.0/OS 10.10@
  57  */
  58
  59 int                                     /* O - 1 on success, 0 on failure */
  60 cupsMakeServerCredentials(
  61     const char *path,                   /* I - Path to keychain/directory */
  62     const char *common_name,            /* I - Common name */
  63     int        num_alt_names,           /* I - Number of subject alternate names */
  64     const char **alt_names,             /* I - Subject Alternate Names */
  65     time_t     expiration_date)         /* I - Expiration date */
  66 {
  67   gnutls_x509_crt_t     crt;            /* Self-signed certificate */
  68   gnutls_x509_privkey_t key;            /* Encryption private key */
  69   char                  temp[1024],     /* Temporary directory name */
  70                         crtfile[1024],  /* Certificate filename */
  71                         keyfile[1024];  /* Private key filename */
  72   cups_lang_t           *language;      /* Default language info */
  73   cups_file_t           *fp;            /* Key/cert file */
  74   unsigned char         buffer[8192];   /* Buffer for x509 data */
  75   size_t                bytes;          /* Number of bytes of data */
  76   unsigned char         serial[4];      /* Serial number buffer */
  77   time_t                curtime;        /* Current time */
  78   int                   result;         /* Result of GNU TLS calls */
  79
  80
  81   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));
  82
  83  /*
  84   * Filenames...
  85   */
  86
  87   if (!path)
  88     path = http_gnutls_default_path(temp, sizeof(temp));
  89
  90   if (!path || !common_name)
  91   {
  92     _cupsSetError(IPP_STATUS_ERROR_INTERNAL, strerror(EINVAL), 0);
  93     return (0);
  94   }
  95
  96   http_gnutls_make_path(crtfile, sizeof(crtfile), path, common_name, "crt");
  97   http_gnutls_make_path(keyfile, sizeof(keyfile), path, common_name, "key");
  98
  99  /*
 100   * Create the encryption key...
 101   */
 102
 103   DEBUG_puts("1cupsMakeServerCredentials: Creating key pair.");
 104
 105   gnutls_x509_privkey_init(&key);
 106   gnutls_x509_privkey_generate(key, GNUTLS_PK_RSA, 2048, 0);
 107
 108   DEBUG_puts("1cupsMakeServerCredentials: Key pair created.");
 109
 110  /*
 111   * Save it...
 112   */
 113
 114   bytes = sizeof(buffer);
 115
 116   if ((result = gnutls_x509_privkey_export(key, GNUTLS_X509_FMT_PEM, buffer, &bytes)) < 0)
 117   {
 118     DEBUG_printf(("1cupsMakeServerCredentials: Unable to export private key: %s", gnutls_strerror(result)));
 119     _cupsSetError(IPP_STATUS_ERROR_INTERNAL, gnutls_strerror(result), 0);
 120     gnutls_x509_privkey_deinit(key);
 121     return (0);
 122   }
 123   else if ((fp = cupsFileOpen(keyfile, "w")) != NULL)
 124   {
 125     DEBUG_printf(("1cupsMakeServerCredentials: Writing private key to \"%s\".", keyfile));
 126     cupsFileWrite(fp, (char *)buffer, bytes);
 127     cupsFileClose(fp);
 128   }
 129   else
 130   {
 131     DEBUG_printf(("1cupsMakeServerCredentials: Unable to create private key file \"%s\": %s", keyfile, strerror(errno)));
 132     _cupsSetError(IPP_STATUS_ERROR_INTERNAL, strerror(errno), 0);
 133     gnutls_x509_privkey_deinit(key);
 134     return (0);
 135   }
 136
 137  /*
 138   * Create the self-signed certificate...
 139   */
 140
 141   DEBUG_puts("1cupsMakeServerCredentials: Generating self-signed X.509 certificate.");
 142
 143   language  = cupsLangDefault();
 144   curtime   = time(NULL);
 145   serial[0] = curtime >> 24;
 146   serial[1] = curtime >> 16;
 147   serial[2] = curtime >> 8;
 148   serial[3] = curtime;
 149
 150   gnutls_x509_crt_init(&crt);
 151   if (strlen(language->language) == 5)
 152     gnutls_x509_crt_set_dn_by_oid(crt, GNUTLS_OID_X520_COUNTRY_NAME, 0,
 153                                   language->language + 3, 2);
 154   else
 155     gnutls_x509_crt_set_dn_by_oid(crt, GNUTLS_OID_X520_COUNTRY_NAME, 0,
 156                                   "US", 2);
 157   gnutls_x509_crt_set_dn_by_oid(crt, GNUTLS_OID_X520_COMMON_NAME, 0,
 158                                 common_name, strlen(common_name));
 159   gnutls_x509_crt_set_dn_by_oid(crt, GNUTLS_OID_X520_ORGANIZATION_NAME, 0,
 160                                 common_name, strlen(common_name));
 161   gnutls_x509_crt_set_dn_by_oid(crt, GNUTLS_OID_X520_ORGANIZATIONAL_UNIT_NAME,
 162                                 0, "Unknown", 7);
 163   gnutls_x509_crt_set_dn_by_oid(crt, GNUTLS_OID_X520_STATE_OR_PROVINCE_NAME, 0,
 164                                 "Unknown", 7);
 165   gnutls_x509_crt_set_dn_by_oid(crt, GNUTLS_OID_X520_LOCALITY_NAME, 0,
 166                                 "Unknown", 7);
 167 /*  gnutls_x509_crt_set_dn_by_oid(crt, GNUTLS_OID_PKCS9_EMAIL, 0,
 168                                 ServerAdmin, strlen(ServerAdmin));*/
 169   gnutls_x509_crt_set_key(crt, key);
 170   gnutls_x509_crt_set_serial(crt, serial, sizeof(serial));
 171   gnutls_x509_crt_set_activation_time(crt, curtime);
 172   gnutls_x509_crt_set_expiration_time(crt, curtime + 10 * 365 * 86400);
 173   gnutls_x509_crt_set_ca_status(crt, 0);
 174   if (num_alt_names > 0)
 175     gnutls_x509_crt_set_subject_alternative_name(crt, GNUTLS_SAN_DNSNAME, alt_names[0]);
 176   gnutls_x509_crt_set_key_purpose_oid(crt, GNUTLS_KP_TLS_WWW_SERVER, 0);
 177   gnutls_x509_crt_set_key_usage(crt, GNUTLS_KEY_KEY_ENCIPHERMENT);
 178   gnutls_x509_crt_set_version(crt, 3);
 179
 180   bytes = sizeof(buffer);
 181   if (gnutls_x509_crt_get_key_id(crt, 0, buffer, &bytes) >= 0)
 182     gnutls_x509_crt_set_subject_key_id(crt, buffer, bytes);
 183
 184   gnutls_x509_crt_sign(crt, crt, key);
 185
 186  /*
 187   * Save it...
 188   */
 189
 190   bytes = sizeof(buffer);
 191   if ((result = gnutls_x509_crt_export(crt, GNUTLS_X509_FMT_PEM, buffer, &bytes)) < 0)
 192   {
 193     DEBUG_printf(("1cupsMakeServerCredentials: Unable to export public key and X.509 certificate: %s", gnutls_strerror(result)));
 194     _cupsSetError(IPP_STATUS_ERROR_INTERNAL, gnutls_strerror(result), 0);
 195     gnutls_x509_crt_deinit(crt);
 196     gnutls_x509_privkey_deinit(key);
 197     return (0);
 198   }
 199   else if ((fp = cupsFileOpen(crtfile, "w")) != NULL)
 200   {
 201     DEBUG_printf(("1cupsMakeServerCredentials: Writing public key and X.509 certificate to \"%s\".", crtfile));
 202     cupsFileWrite(fp, (char *)buffer, bytes);
 203     cupsFileClose(fp);
 204   }
 205   else
 206   {
 207     DEBUG_printf(("1cupsMakeServerCredentials: Unable to create public key and X.509 certificate file \"%s\": %s", crtfile, strerror(errno)));
 208     _cupsSetError(IPP_STATUS_ERROR_INTERNAL, strerror(errno), 0);
 209     gnutls_x509_crt_deinit(crt);
 210     gnutls_x509_privkey_deinit(key);
 211     return (0);
 212   }
 213
 214  /*
 215   * Cleanup...
 216   */
 217
 218   gnutls_x509_crt_deinit(crt);
 219   gnutls_x509_privkey_deinit(key);
 220
 221   DEBUG_puts("1cupsMakeServerCredentials: Successfully created credentials.");
 222
 223   return (1);
 224 }
 225
 226
 227 /*
 228  * 'cupsSetServerCredentials()' - Set the default server credentials.
 229  *
 230  * Note: The server credentials are used by all threads in the running process.
 231  * This function is threadsafe.
 232  *
 233  * @since CUPS 2.0/OS 10.10@
 234  */
 235
 236 int                                     /* O - 1 on success, 0 on failure */
 237 cupsSetServerCredentials(
 238     const char *path,                   /* I - Path to keychain/directory */
 239     const char *common_name,            /* I - Default common name for server */
 240     int        auto_create)             /* I - 1 = automatically create self-signed certificates */
 241 {
 242   char  temp[1024];                     /* Default path buffer */
 243
 244
 245   DEBUG_printf(("cupsSetServerCredentials(path=\"%s\", common_name=\"%s\", auto_create=%d)", path, common_name, auto_create));
 246
 247  /*
 248   * Use defaults as needed...
 249   */
 250
 251   if (!path)
 252     path = http_gnutls_default_path(temp, sizeof(temp));
 253
 254  /*
 255   * Range check input...
 256   */
 257
 258   if (!path || !common_name)
 259   {
 260     _cupsSetError(IPP_STATUS_ERROR_INTERNAL, strerror(EINVAL), 0);
 261     return (0);
 262   }
 263
 264   _cupsMutexLock(&tls_mutex);
 265
 266  /*
 267   * Free old values...
 268   */
 269
 270   if (tls_keypath)
 271     _cupsStrFree(tls_keypath);
 272
 273   if (tls_common_name)
 274     _cupsStrFree(tls_common_name);
 275
 276  /*
 277   * Save the new values...
 278   */
 279
 280   tls_keypath     = _cupsStrAlloc(path);
 281   tls_auto_create = auto_create;
 282   tls_common_name = _cupsStrAlloc(common_name);
 283
 284   _cupsMutexUnlock(&tls_mutex);
 285
 286   return (1);
 287 }
 288
 289
 290 /*
 291  * 'httpCopyCredentials()' - Copy the credentials associated with the peer in
 292  *                           an encrypted connection.
 293  *
 294  * @since CUPS 1.5/macOS 10.7@
 295  */
 296
 297 int                                     /* O - Status of call (0 = success) */
 298 httpCopyCredentials(
 299     http_t       *http,                 /* I - Connection to server */
 300     cups_array_t **credentials)         /* O - Array of credentials */
 301 {
 302   unsigned              count;          /* Number of certificates */
 303   const gnutls_datum_t *certs;          /* Certificates */
 304
 305
 306   DEBUG_printf(("httpCopyCredentials(http=%p, credentials=%p)", http, credentials));
 307
 308   if (credentials)
 309     *credentials = NULL;
 310
 311   if (!http || !http->tls || !credentials)
 312     return (-1);
 313
 314   *credentials = cupsArrayNew(NULL, NULL);
 315   certs        = gnutls_certificate_get_peers(http->tls, &count);
 316
 317   DEBUG_printf(("1httpCopyCredentials: certs=%p, count=%u", certs, count));
 318
 319   if (certs && count)
 320   {
 321     while (count > 0)
 322     {
 323       httpAddCredential(*credentials, certs->data, certs->size);
 324       certs ++;
 325       count --;
 326     }
 327   }
 328
 329   return (0);
 330 }
 331
 332
 333 /*
 334  * '_httpCreateCredentials()' - Create credentials in the internal format.
 335  */
 336
 337 http_tls_credentials_t                  /* O - Internal credentials */
 338 _httpCreateCredentials(
 339     cups_array_t *credentials)          /* I - Array of credentials */
 340 {
 341   (void)credentials;
 342
 343   return (NULL);
 344 }
 345
 346
 347 /*
 348  * '_httpFreeCredentials()' - Free internal credentials.
 349  */
 350
 351 void
 352 _httpFreeCredentials(
 353     http_tls_credentials_t credentials) /* I - Internal credentials */
 354 {
 355   (void)credentials;
 356 }
 357
 358
 359 /*
 360  * 'httpCredentialsAreValidForName()' - Return whether the credentials are valid for the given name.
 361  *
 362  * @since CUPS 2.0/OS 10.10@
 363  */
 364
 365 int                                     /* O - 1 if valid, 0 otherwise */
 366 httpCredentialsAreValidForName(
 367     cups_array_t *credentials,          /* I - Credentials */
 368     const char   *common_name)          /* I - Name to check */
 369 {
 370   gnutls_x509_crt_t     cert;           /* Certificate */
 371   int                   result = 0;     /* Result */
 372
 373
 374   cert = http_gnutls_create_credential((http_credential_t *)cupsArrayFirst(credentials));
 375   if (cert)
 376   {
 377     result = gnutls_x509_crt_check_hostname(cert, common_name) != 0;
 378
 379     if (result)
 380     {
 381       int               i,              /* Looping var */
 382                         count;          /* Number of revoked certificates */
 383       unsigned char     cserial[1024],  /* Certificate serial number */
 384                         rserial[1024];  /* Revoked serial number */
 385       size_t            cserial_size,   /* Size of cert serial number */
 386                         rserial_size;   /* Size of revoked serial number */
 387
 388       _cupsMutexLock(&tls_mutex);
 389
 390       count = gnutls_x509_crl_get_crt_count(tls_crl);
 391
 392       if (count > 0)
 393       {
 394         cserial_size = sizeof(cserial);
 395         gnutls_x509_crt_get_serial(cert, cserial, &cserial_size);
 396
 397         for (i = 0; i < count; i ++)
 398         {
 399           rserial_size = sizeof(rserial);
 400           if (!gnutls_x509_crl_get_crt_serial(tls_crl, i, rserial, &rserial_size, NULL) && cserial_size == rserial_size && !memcmp(cserial, rserial, rserial_size))
 401           {
 402             result = 0;
 403             break;
 404           }
 405         }
 406       }
 407
 408       _cupsMutexUnlock(&tls_mutex);
 409     }
 410
 411     gnutls_x509_crt_deinit(cert);
 412   }
 413
 414   return (result);
 415 }
 416
 417
 418 /*
 419  * 'httpCredentialsGetTrust()' - Return the trust of credentials.
 420  *
 421  * @since CUPS 2.0/OS 10.10@
 422  */
 423
 424 http_trust_t                            /* O - Level of trust */
 425 httpCredentialsGetTrust(
 426     cups_array_t *credentials,          /* I - Credentials */
 427     const char   *common_name)          /* I - Common name for trust lookup */
 428 {
 429   http_trust_t          trust = HTTP_TRUST_OK;
 430                                         /* Trusted? */
 431   gnutls_x509_crt_t     cert;           /* Certificate */
 432   cups_array_t          *tcreds = NULL; /* Trusted credentials */
 433   _cups_globals_t       *cg = _cupsGlobals();
 434                                         /* Per-thread globals */
 435
 436
 437   if (!common_name)
 438   {
 439     _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("No common name specified."), 1);
 440     return (HTTP_TRUST_UNKNOWN);
 441   }
 442
 443   if ((cert = http_gnutls_create_credential((http_credential_t *)cupsArrayFirst(credentials))) == NULL)
 444   {
 445     _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("Unable to create credentials from array."), 1);
 446     return (HTTP_TRUST_UNKNOWN);
 447   }
 448
 449   if (cg->any_root < 0)
 450   {
 451     _cupsSetDefaults();
 452     http_gnutls_load_crl();
 453   }
 454
 455  /*
 456   * Look this common name up in the default keychains...
 457   */
 458
 459   httpLoadCredentials(NULL, &tcreds, common_name);
 460
 461   if (tcreds)
 462   {
 463     char        credentials_str[1024],  /* String for incoming credentials */
 464                 tcreds_str[1024];       /* String for saved credentials */
 465
 466     httpCredentialsString(credentials, credentials_str, sizeof(credentials_str));
 467     httpCredentialsString(tcreds, tcreds_str, sizeof(tcreds_str));
 468
 469     if (strcmp(credentials_str, tcreds_str))
 470     {
 471      /*
 472       * Credentials don't match, let's look at the expiration date of the new
 473       * credentials and allow if the new ones have a later expiration...
 474       */
 475
 476       if (!cg->trust_first)
 477       {
 478        /*
 479         * Do not trust certificates on first use...
 480         */
 481
 482         _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("Trust on first use is disabled."), 1);
 483
 484         trust = HTTP_TRUST_INVALID;
 485       }
 486       else if (httpCredentialsGetExpiration(credentials) <= httpCredentialsGetExpiration(tcreds))
 487       {
 488        /*
 489         * The new credentials are not newly issued...
 490         */
 491
 492         _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("New credentials are older than stored credentials."), 1);
 493
 494         trust = HTTP_TRUST_INVALID;
 495       }
 496       else if (!httpCredentialsAreValidForName(credentials, common_name))
 497       {
 498        /*
 499         * The common name does not match the issued certificate...
 500         */
 501
 502         _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("New credentials are not valid for name."), 1);
 503
 504         trust = HTTP_TRUST_INVALID;
 505       }
 506       else if (httpCredentialsGetExpiration(tcreds) < time(NULL))
 507       {
 508        /*
 509         * Save the renewed credentials...
 510         */
 511
 512         trust = HTTP_TRUST_RENEWED;
 513
 514         httpSaveCredentials(NULL, credentials, common_name);
 515       }
 516     }
 517
 518     httpFreeCredentials(tcreds);
 519   }
 520   else if (cg->validate_certs && !httpCredentialsAreValidForName(credentials, common_name))
 521   {
 522     _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("No stored credentials, not valid for name."), 1);
 523     trust = HTTP_TRUST_INVALID;
 524   }
 525   else if (!cg->trust_first)
 526   {
 527     _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("Trust on first use is disabled."), 1);
 528     trust = HTTP_TRUST_INVALID;
 529   }
 530
 531   if (trust == HTTP_TRUST_OK && !cg->expired_certs)
 532   {
 533     time_t      curtime;                /* Current date/time */
 534
 535     time(&curtime);
 536     if (curtime < gnutls_x509_crt_get_activation_time(cert) ||
 537         curtime > gnutls_x509_crt_get_expiration_time(cert))
 538     {
 539       _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("Credentials have expired."), 1);
 540       trust = HTTP_TRUST_EXPIRED;
 541     }
 542   }
 543
 544   if (trust == HTTP_TRUST_OK && !cg->any_root && cupsArrayCount(credentials) == 1)
 545   {
 546     _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("Self-signed credentials are blocked."), 1);
 547     trust = HTTP_TRUST_INVALID;
 548   }
 549
 550   gnutls_x509_crt_deinit(cert);
 551
 552   return (trust);
 553 }
 554
 555
 556 /*
 557  * 'httpCredentialsGetExpiration()' - Return the expiration date of the credentials.
 558  *
 559  * @since CUPS 2.0/OS 10.10@
 560  */
 561
 562 time_t                                  /* O - Expiration date of credentials */
 563 httpCredentialsGetExpiration(
 564     cups_array_t *credentials)          /* I - Credentials */
 565 {
 566   gnutls_x509_crt_t     cert;           /* Certificate */
 567   time_t                result = 0;     /* Result */
 568
 569
 570   cert = http_gnutls_create_credential((http_credential_t *)cupsArrayFirst(credentials));
 571   if (cert)
 572   {
 573     result = gnutls_x509_crt_get_expiration_time(cert);
 574     gnutls_x509_crt_deinit(cert);
 575   }
 576
 577   return (result);
 578 }
 579
 580
 581 /*
 582  * 'httpCredentialsString()' - Return a string representing the credentials.
 583  *
 584  * @since CUPS 2.0/OS 10.10@
 585  */
 586
 587 size_t                                  /* O - Total size of credentials string */
 588 httpCredentialsString(
 589     cups_array_t *credentials,          /* I - Credentials */
 590     char         *buffer,               /* I - Buffer or @code NULL@ */
 591     size_t       bufsize)               /* I - Size of buffer */
 592 {
 593   http_credential_t     *first;         /* First certificate */
 594   gnutls_x509_crt_t     cert;           /* Certificate */
 595
 596
 597   DEBUG_printf(("httpCredentialsString(credentials=%p, buffer=%p, bufsize=" CUPS_LLFMT ")", credentials, buffer, CUPS_LLCAST bufsize));
 598
 599   if (!buffer)
 600     return (0);
 601
 602   if (buffer && bufsize > 0)
 603     *buffer = '\0';
 604
 605   if ((first = (http_credential_t *)cupsArrayFirst(credentials)) != NULL &&
 606       (cert = http_gnutls_create_credential(first)) != NULL)
 607   {
 608     char                name[256];      /* Common name associated with cert */
 609     size_t              namelen;        /* Length of name */
 610     time_t              expiration;     /* Expiration date of cert */
 611     _cups_md5_state_t   md5_state;      /* MD5 state */
 612     unsigned char       md5_digest[16]; /* MD5 result */
 613
 614     namelen = sizeof(name) - 1;
 615     if (gnutls_x509_crt_get_dn_by_oid(cert, GNUTLS_OID_X520_COMMON_NAME, 0, 0, name, &namelen) >= 0)
 616       name[namelen] = '\0';
 617     else
 618       strlcpy(name, "unknown", sizeof(name));
 619
 620     expiration = gnutls_x509_crt_get_expiration_time(cert);
 621
 622     _cupsMD5Init(&md5_state);
 623     _cupsMD5Append(&md5_state, first->data, (int)first->datalen);
 624     _cupsMD5Finish(&md5_state, md5_digest);
 625
 626     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]);
 627
 628     gnutls_x509_crt_deinit(cert);
 629   }
 630
 631   DEBUG_printf(("1httpCredentialsString: Returning \"%s\".", buffer));
 632
 633   return (strlen(buffer));
 634 }
 635
 636
 637 /*
 638  * 'httpLoadCredentials()' - Load X.509 credentials from a keychain file.
 639  *
 640  * @since CUPS 2.0/OS 10.10@
 641  */
 642
 643 int                                     /* O - 0 on success, -1 on error */
 644 httpLoadCredentials(
 645     const char   *path,                 /* I  - Keychain/PKCS#12 path */
 646     cups_array_t **credentials,         /* IO - Credentials */
 647     const char   *common_name)          /* I  - Common name for credentials */
 648 {
 649   cups_file_t           *fp;            /* Certificate file */
 650   char                  filename[1024], /* filename.crt */
 651                         temp[1024],     /* Temporary string */
 652                         line[256];      /* Base64-encoded line */
 653   unsigned char         *data = NULL;   /* Buffer for cert data */
 654   size_t                alloc_data = 0, /* Bytes allocated */
 655                         num_data = 0;   /* Bytes used */
 656   int                   decoded;        /* Bytes decoded */
 657   int                   in_certificate = 0;
 658                                         /* In a certificate? */
 659
 660
 661   if (!credentials || !common_name)
 662     return (-1);
 663
 664   if (!path)
 665     path = http_gnutls_default_path(temp, sizeof(temp));
 666   if (!path)
 667     return (-1);
 668
 669   http_gnutls_make_path(filename, sizeof(filename), path, common_name, "crt");
 670
 671   if ((fp = cupsFileOpen(filename, "r")) == NULL)
 672     return (-1);
 673
 674   while (cupsFileGets(fp, line, sizeof(line)))
 675   {
 676     if (!strcmp(line, "-----BEGIN CERTIFICATE-----"))
 677     {
 678       if (in_certificate)
 679       {
 680        /*
 681         * Missing END CERTIFICATE...
 682         */
 683
 684         httpFreeCredentials(*credentials);
 685         *credentials = NULL;
 686         break;
 687       }
 688
 689       in_certificate = 1;
 690     }
 691     else if (!strcmp(line, "-----END CERTIFICATE-----"))
 692     {
 693       if (!in_certificate || !num_data)
 694       {
 695        /*
 696         * Missing data...
 697         */
 698
 699         httpFreeCredentials(*credentials);
 700         *credentials = NULL;
 701         break;
 702       }
 703
 704       if (!*credentials)
 705         *credentials = cupsArrayNew(NULL, NULL);
 706
 707       if (httpAddCredential(*credentials, data, num_data))
 708       {
 709         httpFreeCredentials(*credentials);
 710         *credentials = NULL;
 711         break;
 712       }
 713
 714       num_data       = 0;
 715       in_certificate = 0;
 716     }
 717     else if (in_certificate)
 718     {
 719       if (alloc_data == 0)
 720       {
 721         data       = malloc(2048);
 722         alloc_data = 2048;
 723
 724         if (!data)
 725           break;
 726       }
 727       else if ((num_data + strlen(line)) >= alloc_data)
 728       {
 729         unsigned char *tdata = realloc(data, alloc_data + 1024);
 730                                         /* Expanded buffer */
 731
 732         if (!tdata)
 733         {
 734           httpFreeCredentials(*credentials);
 735           *credentials = NULL;
 736           break;
 737         }
 738
 739         data       = tdata;
 740         alloc_data += 1024;
 741       }
 742
 743       decoded = alloc_data - num_data;
 744       httpDecode64_2((char *)data + num_data, &decoded, line);
 745       num_data += (size_t)decoded;
 746     }
 747   }
 748
 749   cupsFileClose(fp);
 750
 751   if (in_certificate)
 752   {
 753    /*
 754     * Missing END CERTIFICATE...
 755     */
 756
 757     httpFreeCredentials(*credentials);
 758     *credentials = NULL;
 759   }
 760
 761   if (data)
 762     free(data);
 763
 764   return (*credentials ? 0 : -1);
 765 }
 766
 767
 768 /*
 769  * 'httpSaveCredentials()' - Save X.509 credentials to a keychain file.
 770  *
 771  * @since CUPS 2.0/OS 10.10@
 772  */
 773
 774 int                                     /* O - -1 on error, 0 on success */
 775 httpSaveCredentials(
 776     const char   *path,                 /* I - Keychain/PKCS#12 path */
 777     cups_array_t *credentials,          /* I - Credentials */
 778     const char   *common_name)          /* I - Common name for credentials */
 779 {
 780   cups_file_t           *fp;            /* Certificate file */
 781   char                  filename[1024], /* filename.crt */
 782                         nfilename[1024],/* filename.crt.N */
 783                         temp[1024],     /* Temporary string */
 784                         line[256];      /* Base64-encoded line */
 785   const unsigned char   *ptr;           /* Pointer into certificate */
 786   ssize_t               remaining;      /* Bytes left */
 787   http_credential_t     *cred;          /* Current credential */
 788
 789
 790   if (!credentials || !common_name)
 791     return (-1);
 792
 793   if (!path)
 794     path = http_gnutls_default_path(temp, sizeof(temp));
 795   if (!path)
 796     return (-1);
 797
 798   http_gnutls_make_path(filename, sizeof(filename), path, common_name, "crt");
 799   snprintf(nfilename, sizeof(nfilename), "%s.N", filename);
 800
 801   if ((fp = cupsFileOpen(nfilename, "w")) == NULL)
 802     return (-1);
 803
 804   fchmod(cupsFileNumber(fp), 0600);
 805
 806   for (cred = (http_credential_t *)cupsArrayFirst(credentials);
 807        cred;
 808        cred = (http_credential_t *)cupsArrayNext(credentials))
 809   {
 810     cupsFilePuts(fp, "-----BEGIN CERTIFICATE-----\n");
 811     for (ptr = cred->data, remaining = (ssize_t)cred->datalen; remaining > 0; remaining -= 45, ptr += 45)
 812     {
 813       httpEncode64_2(line, sizeof(line), (char *)ptr, remaining > 45 ? 45 : remaining);
 814       cupsFilePrintf(fp, "%s\n", line);
 815     }
 816     cupsFilePuts(fp, "-----END CERTIFICATE-----\n");
 817   }
 818
 819   cupsFileClose(fp);
 820
 821   return (rename(nfilename, filename));
 822 }
 823
 824
 825 /*
 826  * 'http_gnutls_create_credential()' - Create a single credential in the internal format.
 827  */
 828
 829 static gnutls_x509_crt_t                        /* O - Certificate */
 830 http_gnutls_create_credential(
 831     http_credential_t *credential)              /* I - Credential */
 832 {
 833   int                   result;                 /* Result from GNU TLS */
 834   gnutls_x509_crt_t     cert;                   /* Certificate */
 835   gnutls_datum_t        datum;                  /* Data record */
 836
 837
 838   DEBUG_printf(("3http_gnutls_create_credential(credential=%p)", credential));
 839
 840   if (!credential)
 841     return (NULL);
 842
 843   if ((result = gnutls_x509_crt_init(&cert)) < 0)
 844   {
 845     DEBUG_printf(("4http_gnutls_create_credential: init error: %s", gnutls_strerror(result)));
 846     return (NULL);
 847   }
 848
 849   datum.data = credential->data;
 850   datum.size = credential->datalen;
 851
 852   if ((result = gnutls_x509_crt_import(cert, &datum, GNUTLS_X509_FMT_DER)) < 0)
 853   {
 854     DEBUG_printf(("4http_gnutls_create_credential: import error: %s", gnutls_strerror(result)));
 855
 856     gnutls_x509_crt_deinit(cert);
 857     return (NULL);
 858   }
 859
 860   return (cert);
 861 }
 862
 863
 864 /*
 865  * 'http_gnutls_default_path()' - Get the default credential store path.
 866  */
 867
 868 static const char *                     /* O - Path or NULL on error */
 869 http_gnutls_default_path(char   *buffer,/* I - Path buffer */
 870                          size_t bufsize)/* I - Size of path buffer */
 871 {
 872   const char *home = getenv("HOME");    /* HOME environment variable */
 873
 874
 875   if (getuid() && home)
 876   {
 877     snprintf(buffer, bufsize, "%s/.cups", home);
 878     if (access(buffer, 0))
 879     {
 880       DEBUG_printf(("1http_gnutls_default_path: Making directory \"%s\".", buffer));
 881       if (mkdir(buffer, 0700))
 882       {
 883         DEBUG_printf(("1http_gnutls_default_path: Failed to make directory: %s", strerror(errno)));
 884         return (NULL);
 885       }
 886     }
 887
 888     snprintf(buffer, bufsize, "%s/.cups/ssl", home);
 889     if (access(buffer, 0))
 890     {
 891       DEBUG_printf(("1http_gnutls_default_path: Making directory \"%s\".", buffer));
 892       if (mkdir(buffer, 0700))
 893       {
 894         DEBUG_printf(("1http_gnutls_default_path: Failed to make directory: %s", strerror(errno)));
 895         return (NULL);
 896       }
 897     }
 898   }
 899   else
 900     strlcpy(buffer, CUPS_SERVERROOT "/ssl", bufsize);
 901
 902   DEBUG_printf(("1http_gnutls_default_path: Using default path \"%s\".", buffer));
 903
 904   return (buffer);
 905 }
 906
 907
 908 /*
 909  * 'http_gnutls_load_crl()' - Load the certificate revocation list, if any.
 910  */
 911
 912 static void
 913 http_gnutls_load_crl(void)
 914 {
 915   _cupsMutexLock(&tls_mutex);
 916
 917   if (!gnutls_x509_crl_init(&tls_crl))
 918   {
 919     cups_file_t         *fp;            /* CRL file */
 920     char                filename[1024], /* site.crl */
 921                         line[256];      /* Base64-encoded line */
 922     unsigned char       *data = NULL;   /* Buffer for cert data */
 923     size_t              alloc_data = 0, /* Bytes allocated */
 924                         num_data = 0;   /* Bytes used */
 925     int                 decoded;        /* Bytes decoded */
 926     gnutls_datum_t      datum;          /* Data record */
 927
 928
 929     http_gnutls_make_path(filename, sizeof(filename), CUPS_SERVERROOT, "site", "crl");
 930
 931     if ((fp = cupsFileOpen(filename, "r")) != NULL)
 932     {
 933       while (cupsFileGets(fp, line, sizeof(line)))
 934       {
 935         if (!strcmp(line, "-----BEGIN X509 CRL-----"))
 936         {
 937           if (num_data)
 938           {
 939            /*
 940             * Missing END X509 CRL...
 941             */
 942
 943             break;
 944           }
 945         }
 946         else if (!strcmp(line, "-----END X509 CRL-----"))
 947         {
 948           if (!num_data)
 949           {
 950            /*
 951             * Missing data...
 952             */
 953
 954             break;
 955           }
 956
 957           datum.data = data;
 958           datum.size = num_data;
 959
 960           gnutls_x509_crl_import(tls_crl, &datum, GNUTLS_X509_FMT_PEM);
 961
 962           num_data = 0;
 963         }
 964         else
 965         {
 966           if (alloc_data == 0)
 967           {
 968             data       = malloc(2048);
 969             alloc_data = 2048;
 970
 971             if (!data)
 972               break;
 973           }
 974           else if ((num_data + strlen(line)) >= alloc_data)
 975           {
 976             unsigned char *tdata = realloc(data, alloc_data + 1024);
 977                                             /* Expanded buffer */
 978
 979             if (!tdata)
 980               break;
 981
 982             data       = tdata;
 983             alloc_data += 1024;
 984           }
 985
 986           decoded = alloc_data - num_data;
 987           httpDecode64_2((char *)data + num_data, &decoded, line);
 988           num_data += (size_t)decoded;
 989         }
 990       }
 991
 992       cupsFileClose(fp);
 993
 994       if (data)
 995         free(data);
 996     }
 997   }
 998
 999   _cupsMutexUnlock(&tls_mutex);
1000 }
1001
1002
1003 /*
1004  * 'http_gnutls_make_path()' - Format a filename for a certificate or key file.
1005  */
1006
1007 static const char *                     /* O - Filename */
1008 http_gnutls_make_path(
1009     char       *buffer,                 /* I - Filename buffer */
1010     size_t     bufsize,                 /* I - Size of buffer */
1011     const char *dirname,                /* I - Directory */
1012     const char *filename,               /* I - Filename (usually hostname) */
1013     const char *ext)                    /* I - Extension */
1014 {
1015   char  *bufptr,                        /* Pointer into buffer */
1016         *bufend = buffer + bufsize - 1; /* End of buffer */
1017
1018
1019   snprintf(buffer, bufsize, "%s/", dirname);
1020   bufptr = buffer + strlen(buffer);
1021
1022   while (*filename && bufptr < bufend)
1023   {
1024     if (_cups_isalnum(*filename) || *filename == '-' || *filename == '.')
1025       *bufptr++ = *filename;
1026     else
1027       *bufptr++ = '_';
1028
1029     filename ++;
1030   }
1031
1032   if (bufptr < bufend)
1033     *bufptr++ = '.';
1034
1035   strlcpy(bufptr, ext, (size_t)(bufend - bufptr + 1));
1036
1037   return (buffer);
1038 }
1039
1040
1041 /*
1042  * 'http_gnutls_read()' - Read function for the GNU TLS library.
1043  */
1044
1045 static ssize_t                          /* O - Number of bytes read or -1 on error */
1046 http_gnutls_read(
1047     gnutls_transport_ptr_t ptr,         /* I - Connection to server */
1048     void                   *data,       /* I - Buffer */
1049     size_t                 length)      /* I - Number of bytes to read */
1050 {
1051   http_t        *http;                  /* HTTP connection */
1052   ssize_t       bytes;                  /* Bytes read */
1053
1054
1055   DEBUG_printf(("6http_gnutls_read(ptr=%p, data=%p, length=%d)", ptr, data, (int)length));
1056
1057   http = (http_t *)ptr;
1058
1059   if (!http->blocking)
1060   {
1061    /*
1062     * Make sure we have data before we read...
1063     */
1064
1065     while (!_httpWait(http, http->wait_value, 0))
1066     {
1067       if (http->timeout_cb && (*http->timeout_cb)(http, http->timeout_data))
1068         continue;
1069
1070       http->error = ETIMEDOUT;
1071       return (-1);
1072     }
1073   }
1074
1075   bytes = recv(http->fd, data, length, 0);
1076   DEBUG_printf(("6http_gnutls_read: bytes=%d", (int)bytes));
1077   return (bytes);
1078 }
1079
1080
1081 /*
1082  * 'http_gnutls_write()' - Write function for the GNU TLS library.
1083  */
1084
1085 static ssize_t                          /* O - Number of bytes written or -1 on error */
1086 http_gnutls_write(
1087     gnutls_transport_ptr_t ptr,         /* I - Connection to server */
1088     const void             *data,       /* I - Data buffer */
1089     size_t                 length)      /* I - Number of bytes to write */
1090 {
1091   ssize_t bytes;                        /* Bytes written */
1092
1093
1094   DEBUG_printf(("6http_gnutls_write(ptr=%p, data=%p, length=%d)", ptr, data,
1095                 (int)length));
1096   bytes = send(((http_t *)ptr)->fd, data, length, 0);
1097   DEBUG_printf(("http_gnutls_write: bytes=%d", (int)bytes));
1098
1099   return (bytes);
1100 }
1101
1102
1103 /*
1104  * '_httpTLSInitialize()' - Initialize the TLS stack.
1105  */
1106
1107 void
1108 _httpTLSInitialize(void)
1109 {
1110  /*
1111   * Initialize GNU TLS...
1112   */
1113
1114   gnutls_global_init();
1115 }
1116
1117
1118 /*
1119  * '_httpTLSPending()' - Return the number of pending TLS-encrypted bytes.
1120  */
1121
1122 size_t                                  /* O - Bytes available */
1123 _httpTLSPending(http_t *http)           /* I - HTTP connection */
1124 {
1125   return (gnutls_record_check_pending(http->tls));
1126 }
1127
1128
1129 /*
1130  * '_httpTLSRead()' - Read from a SSL/TLS connection.
1131  */
1132
1133 int                                     /* O - Bytes read */
1134 _httpTLSRead(http_t *http,              /* I - Connection to server */
1135              char   *buf,               /* I - Buffer to store data */
1136              int    len)                /* I - Length of buffer */
1137 {
1138   ssize_t       result;                 /* Return value */
1139
1140
1141   result = gnutls_record_recv(http->tls, buf, (size_t)len);
1142
1143   if (result < 0 && !errno)
1144   {
1145    /*
1146     * Convert GNU TLS error to errno value...
1147     */
1148
1149     switch (result)
1150     {
1151       case GNUTLS_E_INTERRUPTED :
1152           errno = EINTR;
1153           break;
1154
1155       case GNUTLS_E_AGAIN :
1156           errno = EAGAIN;
1157           break;
1158
1159       default :
1160           errno = EPIPE;
1161           break;
1162     }
1163
1164     result = -1;
1165   }
1166
1167   return ((int)result);
1168 }
1169
1170
1171 /*
1172  * '_httpTLSSetCredentials()' - Set the TLS credentials.
1173  */
1174
1175 int                                     /* O - Status of connection */
1176 _httpTLSSetCredentials(http_t *http)    /* I - Connection to server */
1177 {
1178   (void)http;
1179
1180   return (0);
1181 }
1182
1183
1184 /*
1185  * '_httpTLSSetOptions()' - Set TLS protocol and cipher suite options.
1186  */
1187
1188 void
1189 _httpTLSSetOptions(int options)         /* I - Options */
1190 {
1191   tls_options = options;
1192 }
1193
1194
1195 /*
1196  * '_httpTLSStart()' - Set up SSL/TLS support on a connection.
1197  */
1198
1199 int                                     /* O - 0 on success, -1 on failure */
1200 _httpTLSStart(http_t *http)             /* I - Connection to server */
1201 {
1202   char                  hostname[256],  /* Hostname */
1203                         *hostptr;       /* Pointer into hostname */
1204   int                   status;         /* Status of handshake */
1205   gnutls_certificate_credentials_t *credentials;
1206                                         /* TLS credentials */
1207   char                  priority_string[1024];
1208                                         /* Priority string */
1209
1210
1211   DEBUG_printf(("3_httpTLSStart(http=%p)", http));
1212
1213   if (tls_options < 0)
1214   {
1215     DEBUG_puts("4_httpTLSStart: Setting defaults.");
1216     _cupsSetDefaults();
1217     DEBUG_printf(("4_httpTLSStart: tls_options=%x", tls_options));
1218   }
1219
1220   if (http->mode == _HTTP_MODE_SERVER && !tls_keypath)
1221   {
1222     DEBUG_puts("4_httpTLSStart: cupsSetServerCredentials not called.");
1223     http->error  = errno = EINVAL;
1224     http->status = HTTP_STATUS_ERROR;
1225     _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("Server credentials not set."), 1);
1226
1227     return (-1);
1228   }
1229
1230   credentials = (gnutls_certificate_credentials_t *)
1231                     malloc(sizeof(gnutls_certificate_credentials_t));
1232   if (credentials == NULL)
1233   {
1234     DEBUG_printf(("8_httpStartTLS: Unable to allocate credentials: %s",
1235                   strerror(errno)));
1236     http->error  = errno;
1237     http->status = HTTP_STATUS_ERROR;
1238     _cupsSetHTTPError(HTTP_STATUS_ERROR);
1239
1240     return (-1);
1241   }
1242
1243   gnutls_certificate_allocate_credentials(credentials);
1244   status = gnutls_init(&http->tls, http->mode == _HTTP_MODE_CLIENT ? GNUTLS_CLIENT : GNUTLS_SERVER);
1245   if (!status)
1246     status = gnutls_set_default_priority(http->tls);
1247
1248   if (status)
1249   {
1250     http->error  = EIO;
1251     http->status = HTTP_STATUS_ERROR;
1252
1253     DEBUG_printf(("4_httpTLSStart: Unable to initialize common TLS parameters: %s", gnutls_strerror(status)));
1254     _cupsSetError(IPP_STATUS_ERROR_CUPS_PKI, gnutls_strerror(status), 0);
1255
1256     gnutls_deinit(http->tls);
1257     gnutls_certificate_free_credentials(*credentials);
1258     free(credentials);
1259     http->tls = NULL;
1260
1261     return (-1);
1262   }
1263
1264   if (http->mode == _HTTP_MODE_CLIENT)
1265   {
1266    /*
1267     * Client: get the hostname to use for TLS...
1268     */
1269
1270     if (httpAddrLocalhost(http->hostaddr))
1271     {
1272       strlcpy(hostname, "localhost", sizeof(hostname));
1273     }
1274     else
1275     {
1276      /*
1277       * Otherwise make sure the hostname we have does not end in a trailing dot.
1278       */
1279
1280       strlcpy(hostname, http->hostname, sizeof(hostname));
1281       if ((hostptr = hostname + strlen(hostname) - 1) >= hostname &&
1282           *hostptr == '.')
1283         *hostptr = '\0';
1284     }
1285
1286     status = gnutls_server_name_set(http->tls, GNUTLS_NAME_DNS, hostname, strlen(hostname));
1287   }
1288   else
1289   {
1290    /*
1291     * Server: get certificate and private key...
1292     */
1293
1294     char        crtfile[1024],          /* Certificate file */
1295                 keyfile[1024];          /* Private key file */
1296     int         have_creds = 0;         /* Have credentials? */
1297
1298     if (http->fields[HTTP_FIELD_HOST][0])
1299     {
1300      /*
1301       * Use hostname for TLS upgrade...
1302       */
1303
1304       strlcpy(hostname, http->fields[HTTP_FIELD_HOST], sizeof(hostname));
1305     }
1306     else
1307     {
1308      /*
1309       * Resolve hostname from connection address...
1310       */
1311
1312       http_addr_t       addr;           /* Connection address */
1313       socklen_t         addrlen;        /* Length of address */
1314
1315       addrlen = sizeof(addr);
1316       if (getsockname(http->fd, (struct sockaddr *)&addr, &addrlen))
1317       {
1318         DEBUG_printf(("4_httpTLSStart: Unable to get socket address: %s", strerror(errno)));
1319         hostname[0] = '\0';
1320       }
1321       else if (httpAddrLocalhost(&addr))
1322         hostname[0] = '\0';
1323       else
1324       {
1325         httpAddrLookup(&addr, hostname, sizeof(hostname));
1326         DEBUG_printf(("4_httpTLSStart: Resolved socket address to \"%s\".", hostname));
1327       }
1328     }
1329
1330     if (isdigit(hostname[0] & 255) || hostname[0] == '[')
1331       hostname[0] = '\0';               /* Don't allow numeric addresses */
1332
1333     if (hostname[0])
1334     {
1335      /*
1336       * First look for CA certs...
1337       */
1338
1339       snprintf(crtfile, sizeof(crtfile), "/etc/letsencrypt/live/%s/fullchain.pem", hostname);
1340       snprintf(keyfile, sizeof(keyfile), "/etc/letsencrypt/live/%s/privkey.pem", hostname);
1341
1342       if ((access(crtfile, R_OK) || access(keyfile, R_OK)) && (hostptr = strchr(hostname, '.')) != NULL)
1343       {
1344        /*
1345         * Try just domain name...
1346         */
1347
1348         hostptr ++;
1349         if (strchr(hostptr, '.'))
1350         {
1351           snprintf(crtfile, sizeof(crtfile), "/etc/letsencrypt/live/%s/fullchain.pem", hostptr);
1352           snprintf(keyfile, sizeof(keyfile), "/etc/letsencrypt/live/%s/privkey.pem", hostptr);
1353         }
1354       }
1355
1356       if (access(crtfile, R_OK) || access(keyfile, R_OK))
1357       {
1358        /*
1359         * Then look in the CUPS keystore...
1360         */
1361
1362         http_gnutls_make_path(crtfile, sizeof(crtfile), tls_keypath, hostname, "crt");
1363         http_gnutls_make_path(keyfile, sizeof(keyfile), tls_keypath, hostname, "key");
1364       }
1365
1366       have_creds = !access(crtfile, R_OK) && !access(keyfile, R_OK);
1367     }
1368     else if (tls_common_name)
1369     {
1370      /*
1371       * First look for CA certs...
1372       */
1373
1374       snprintf(crtfile, sizeof(crtfile), "/etc/letsencrypt/live/%s/fullchain.pem", tls_common_name);
1375       snprintf(keyfile, sizeof(keyfile), "/etc/letsencrypt/live/%s/privkey.pem", tls_common_name);
1376
1377       if ((access(crtfile, R_OK) || access(keyfile, R_OK)) && (hostptr = strchr(tls_common_name, '.')) != NULL)
1378       {
1379        /*
1380         * Try just domain name...
1381         */
1382
1383         hostptr ++;
1384         if (strchr(hostptr, '.'))
1385         {
1386           snprintf(crtfile, sizeof(crtfile), "/etc/letsencrypt/live/%s/fullchain.pem", hostptr);
1387           snprintf(keyfile, sizeof(keyfile), "/etc/letsencrypt/live/%s/privkey.pem", hostptr);
1388         }
1389       }
1390
1391       if (access(crtfile, R_OK) || access(keyfile, R_OK))
1392       {
1393        /*
1394         * Then look in the CUPS keystore...
1395         */
1396
1397         http_gnutls_make_path(crtfile, sizeof(crtfile), tls_keypath, tls_common_name, "crt");
1398         http_gnutls_make_path(keyfile, sizeof(keyfile), tls_keypath, tls_common_name, "key");
1399       }
1400
1401       have_creds = !access(crtfile, R_OK) && !access(keyfile, R_OK);
1402     }
1403
1404     if (!have_creds && tls_auto_create && (hostname[0] || tls_common_name))
1405     {
1406       DEBUG_printf(("4_httpTLSStart: Auto-create credentials for \"%s\".", hostname[0] ? hostname : tls_common_name));
1407
1408       if (!cupsMakeServerCredentials(tls_keypath, hostname[0] ? hostname : tls_common_name, 0, NULL, time(NULL) + 365 * 86400))
1409       {
1410         DEBUG_puts("4_httpTLSStart: cupsMakeServerCredentials failed.");
1411         http->error  = errno = EINVAL;
1412         http->status = HTTP_STATUS_ERROR;
1413         _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("Unable to create server credentials."), 1);
1414
1415         return (-1);
1416       }
1417     }
1418
1419     DEBUG_printf(("4_httpTLSStart: Using certificate \"%s\" and private key \"%s\".", crtfile, keyfile));
1420
1421     if (!status)
1422       status = gnutls_certificate_set_x509_key_file(*credentials, crtfile, keyfile, GNUTLS_X509_FMT_PEM);
1423   }
1424
1425   if (!status)
1426     status = gnutls_credentials_set(http->tls, GNUTLS_CRD_CERTIFICATE, *credentials);
1427
1428   if (status)
1429   {
1430     http->error  = EIO;
1431     http->status = HTTP_STATUS_ERROR;
1432
1433     DEBUG_printf(("4_httpTLSStart: Unable to complete client/server setup: %s", gnutls_strerror(status)));
1434     _cupsSetError(IPP_STATUS_ERROR_CUPS_PKI, gnutls_strerror(status), 0);
1435
1436     gnutls_deinit(http->tls);
1437     gnutls_certificate_free_credentials(*credentials);
1438     free(credentials);
1439     http->tls = NULL;
1440
1441     return (-1);
1442   }
1443
1444   strlcpy(priority_string, "NORMAL", sizeof(priority_string));
1445
1446   if (tls_options & _HTTP_TLS_DENY_TLS10)
1447     strlcat(priority_string, ":+VERS-TLS-ALL:-VERS-TLS1.0:-VERS-SSL3.0", sizeof(priority_string));
1448   else if (tls_options & _HTTP_TLS_ALLOW_SSL3)
1449     strlcat(priority_string, ":+VERS-TLS-ALL", sizeof(priority_string));
1450   else
1451     strlcat(priority_string, ":+VERS-TLS-ALL:-VERS-SSL3.0", sizeof(priority_string));
1452
1453   if (!(tls_options & _HTTP_TLS_ALLOW_RC4))
1454     strlcat(priority_string, ":-ARCFOUR-128", sizeof(priority_string));
1455
1456   if (!(tls_options & _HTTP_TLS_ALLOW_DH))
1457     strlcat(priority_string, ":!ANON-DH", sizeof(priority_string));
1458
1459 #ifdef HAVE_GNUTLS_PRIORITY_SET_DIRECT
1460   gnutls_priority_set_direct(http->tls, priority_string, NULL);
1461
1462 #else
1463   gnutls_priority_t priority;           /* Priority */
1464
1465   gnutls_priority_init(&priority, priority_string, NULL);
1466   gnutls_priority_set(http->tls, priority);
1467   gnutls_priority_deinit(priority);
1468 #endif /* HAVE_GNUTLS_PRIORITY_SET_DIRECT */
1469
1470   gnutls_transport_set_ptr(http->tls, (gnutls_transport_ptr_t)http);
1471   gnutls_transport_set_pull_function(http->tls, http_gnutls_read);
1472 #ifdef HAVE_GNUTLS_TRANSPORT_SET_PULL_TIMEOUT_FUNCTION
1473   gnutls_transport_set_pull_timeout_function(http->tls, (gnutls_pull_timeout_func)httpWait);
1474 #endif /* HAVE_GNUTLS_TRANSPORT_SET_PULL_TIMEOUT_FUNCTION */
1475   gnutls_transport_set_push_function(http->tls, http_gnutls_write);
1476
1477   while ((status = gnutls_handshake(http->tls)) != GNUTLS_E_SUCCESS)
1478   {
1479     DEBUG_printf(("5_httpStartTLS: gnutls_handshake returned %d (%s)",
1480                   status, gnutls_strerror(status)));
1481
1482     if (gnutls_error_is_fatal(status))
1483     {
1484       http->error  = EIO;
1485       http->status = HTTP_STATUS_ERROR;
1486
1487       _cupsSetError(IPP_STATUS_ERROR_CUPS_PKI, gnutls_strerror(status), 0);
1488
1489       gnutls_deinit(http->tls);
1490       gnutls_certificate_free_credentials(*credentials);
1491       free(credentials);
1492       http->tls = NULL;
1493
1494       return (-1);
1495     }
1496   }
1497
1498   http->tls_credentials = credentials;
1499
1500   return (0);
1501 }
1502
1503
1504 /*
1505  * '_httpTLSStop()' - Shut down SSL/TLS on a connection.
1506  */
1507
1508 void
1509 _httpTLSStop(http_t *http)              /* I - Connection to server */
1510 {
1511   int   error;                          /* Error code */
1512
1513
1514   error = gnutls_bye(http->tls, http->mode == _HTTP_MODE_CLIENT ? GNUTLS_SHUT_RDWR : GNUTLS_SHUT_WR);
1515   if (error != GNUTLS_E_SUCCESS)
1516     _cupsSetError(IPP_STATUS_ERROR_INTERNAL, gnutls_strerror(errno), 0);
1517
1518   gnutls_deinit(http->tls);
1519   http->tls = NULL;
1520
1521   if (http->tls_credentials)
1522   {
1523     gnutls_certificate_free_credentials(*(http->tls_credentials));
1524     free(http->tls_credentials);
1525     http->tls_credentials = NULL;
1526   }
1527 }
1528
1529
1530 /*
1531  * '_httpTLSWrite()' - Write to a SSL/TLS connection.
1532  */
1533
1534 int                                     /* O - Bytes written */
1535 _httpTLSWrite(http_t     *http,         /* I - Connection to server */
1536               const char *buf,          /* I - Buffer holding data */
1537               int        len)           /* I - Length of buffer */
1538 {
1539   ssize_t       result;                 /* Return value */
1540
1541
1542   DEBUG_printf(("2http_write_ssl(http=%p, buf=%p, len=%d)", http, buf, len));
1543
1544   result = gnutls_record_send(http->tls, buf, (size_t)len);
1545
1546   if (result < 0 && !errno)
1547   {
1548    /*
1549     * Convert GNU TLS error to errno value...
1550     */
1551
1552     switch (result)
1553     {
1554       case GNUTLS_E_INTERRUPTED :
1555           errno = EINTR;
1556           break;
1557
1558       case GNUTLS_E_AGAIN :
1559           errno = EAGAIN;
1560           break;
1561
1562       default :
1563           errno = EPIPE;
1564           break;
1565     }
1566
1567     result = -1;
1568   }
1569
1570   DEBUG_printf(("3http_write_ssl: Returning %d.", (int)result));
1571
1572   return ((int)result);
1573 }