cups/auth.c

   1 /*
   2  * "$Id: auth.c 7720 2008-07-11 22:46:21Z mike $"
   3  *
   4  *   Authentication functions for CUPS.
   5  *
   6  *   Copyright 2007-2010 by Apple Inc.
   7  *   Copyright 1997-2007 by Easy Software Products.
   8  *
   9  *   This file contains Kerberos support code, copyright 2006 by
  10  *   Jelmer Vernooij.
  11  *
  12  *   These coded instructions, statements, and computer programs are the
  13  *   property of Apple Inc. and are protected by Federal copyright
  14  *   law.  Distribution and use rights are outlined in the file "LICENSE.txt"
  15  *   which should have been included with this file.  If this file is
  16  *   file is missing or damaged, see the license at "http://www.cups.org/".
  17  *
  18  *   This file is subject to the Apple OS-Developed Software exception.
  19  *
  20  * Contents:
  21  *
  22  *   cupsDoAuthentication() - Authenticate a request.
  23  *   cups_get_gssname()     - Get GSSAPI name for authentication.
  24  *   cups_gss_printf()      - Show error messages from GSSAPI...
  25  *   cups_local_auth()      - Get the local authorization certificate if
  26  *                            available/applicable...
  27  */
  28
  29 /*
  30  * Include necessary headers...
  31  */
  32
  33 #include "cups-private.h"
  34 #include <fcntl.h>
  35 #include <sys/stat.h>
  36 #if defined(WIN32) || defined(__EMX__)
  37 #  include <io.h>
  38 #else
  39 #  include <unistd.h>
  40 #endif /* WIN32 || __EMX__ */
  41
  42 #if HAVE_AUTHORIZATION_H
  43 #  include <Security/Authorization.h>
  44 #  ifdef HAVE_SECBASEPRIV_H
  45 #    include <Security/SecBasePriv.h>
  46 #  else
  47 extern const char *cssmErrorString(int error);
  48 #  endif /* HAVE_SECBASEPRIV_H */
  49 #endif /* HAVE_AUTHORIZATION_H */
  50
  51 #if defined(SO_PEERCRED) && defined(AF_LOCAL)
  52 #  include <pwd.h>
  53 #endif /* SO_PEERCRED && AF_LOCAL */
  54
  55
  56 /*
  57  * Local functions...
  58  */
  59
  60 #ifdef HAVE_GSSAPI
  61 static gss_name_t cups_get_gssname(http_t *http, const char *service_name);
  62 #  ifdef DEBUG
  63 static void     cups_gss_printf(OM_uint32 major_status, OM_uint32 minor_status,
  64                                 const char *message);
  65 #  else
  66 #    define     cups_gss_printf(major, minor, message)
  67 #  endif /* DEBUG */
  68 #endif /* HAVE_GSSAPI */
  69 static int      cups_local_auth(http_t *http);
  70
  71
  72 /*
  73  * 'cupsDoAuthentication()' - Authenticate a request.
  74  *
  75  * This function should be called in response to a @code HTTP_UNAUTHORIZED@
  76  * status, prior to resubmitting your request.
  77  *
  78  * @since CUPS 1.1.20/Mac OS X 10.4@
  79  */
  80
  81 int                                     /* O - 0 on success, -1 on error */
  82 cupsDoAuthentication(
  83     http_t     *http,                   /* I - Connection to server or @code CUPS_HTTP_DEFAULT@ */
  84     const char *method,                 /* I - Request method ("GET", "POST", "PUT") */
  85     const char *resource)               /* I - Resource path */
  86 {
  87   const char    *password;              /* Password string */
  88   char          prompt[1024],           /* Prompt for user */
  89                 realm[HTTP_MAX_VALUE],  /* realm="xyz" string */
  90                 nonce[HTTP_MAX_VALUE];  /* nonce="xyz" string */
  91   int           localauth;              /* Local authentication result */
  92   _cups_globals_t *cg;                  /* Global data */
  93
  94
  95   DEBUG_printf(("cupsDoAuthentication(http=%p, method=\"%s\", resource=\"%s\")",
  96                 http, method, resource));
  97
  98   if (!http)
  99     http = _cupsConnect();
 100
 101   if (!http || !method || !resource)
 102     return (-1);
 103
 104   DEBUG_printf(("2cupsDoAuthentication: digest_tries=%d, userpass=\"%s\"",
 105                 http->digest_tries, http->userpass));
 106   DEBUG_printf(("2cupsDoAuthentication: WWW-Authenticate=\"%s\"",
 107                 httpGetField(http, HTTP_FIELD_WWW_AUTHENTICATE)));
 108
 109  /*
 110   * Clear the current authentication string...
 111   */
 112
 113   httpSetAuthString(http, NULL, NULL);
 114
 115  /*
 116   * See if we can do local authentication...
 117   */
 118
 119   if (http->digest_tries < 3)
 120   {
 121     if ((localauth = cups_local_auth(http)) == 0)
 122     {
 123       DEBUG_printf(("2cupsDoAuthentication: authstring=\"%s\"",
 124                     http->authstring));
 125
 126       if (http->status == HTTP_UNAUTHORIZED)
 127         http->digest_tries ++;
 128
 129       return (0);
 130     }
 131     else if (localauth == -1)
 132     {
 133       http->status = HTTP_AUTHORIZATION_CANCELED;
 134       return (-1);                      /* Error or canceled */
 135     }
 136   }
 137
 138  /*
 139   * Nope, see if we should retry the current username:password...
 140   */
 141
 142   if ((http->digest_tries > 1 || !http->userpass[0]) &&
 143       strncmp(http->fields[HTTP_FIELD_WWW_AUTHENTICATE], "Negotiate", 9))
 144   {
 145    /*
 146     * Nope - get a new password from the user...
 147     */
 148
 149     cg = _cupsGlobals();
 150
 151     if (!cg->lang_default)
 152       cg->lang_default = cupsLangDefault();
 153
 154     snprintf(prompt, sizeof(prompt),
 155              _cupsLangString(cg->lang_default, _("Password for %s on %s? ")),
 156              cupsUser(),
 157              http->hostname[0] == '/' ? "localhost" : http->hostname);
 158
 159     http->digest_tries  = strncasecmp(http->fields[HTTP_FIELD_WWW_AUTHENTICATE],
 160                                       "Digest", 5) != 0;
 161     http->userpass[0]   = '\0';
 162
 163     if ((password = cupsGetPassword2(prompt, http, method, resource)) == NULL)
 164     {
 165       http->status = HTTP_AUTHORIZATION_CANCELED;
 166       return (-1);
 167     }
 168
 169     snprintf(http->userpass, sizeof(http->userpass), "%s:%s", cupsUser(),
 170              password);
 171   }
 172   else if (http->status == HTTP_UNAUTHORIZED)
 173     http->digest_tries ++;
 174
 175   if (http->status == HTTP_UNAUTHORIZED && http->digest_tries >= 3)
 176   {
 177     DEBUG_printf(("1cupsDoAuthentication: Too many authentication tries (%d)",
 178                   http->digest_tries));
 179
 180     http->status = HTTP_AUTHORIZATION_CANCELED;
 181     return (-1);
 182   }
 183
 184  /*
 185   * Got a password; encode it for the server...
 186   */
 187
 188   if (!strncmp(http->fields[HTTP_FIELD_WWW_AUTHENTICATE], "Negotiate", 9))
 189   {
 190 #ifdef HAVE_GSSAPI
 191    /*
 192     * Kerberos authentication...
 193     */
 194
 195     OM_uint32           minor_status,   /* Minor status code */
 196                         major_status;   /* Major status code */
 197     gss_buffer_desc     output_token = GSS_C_EMPTY_BUFFER,
 198                                         /* Output token */
 199                         input_token = GSS_C_EMPTY_BUFFER;
 200                                         /* Input token */
 201     char                *gss_service_name;
 202                                         /* GSS service name */
 203 #  ifdef USE_SPNEGO
 204     const char          *authorization;
 205                                         /* Pointer into Authorization string */
 206 #  endif /* USE_SPNEGO */
 207
 208
 209 #  ifdef __APPLE__
 210    /*
 211     * If the weak-linked GSSAPI/Kerberos library is not present, don't try
 212     * to use it...
 213     */
 214
 215     if (gss_init_sec_context == NULL)
 216     {
 217       DEBUG_puts("1cupsDoAuthentication: Weak-linked GSSAPI/Kerberos framework "
 218                  "is not present");
 219       http->status = HTTP_AUTHORIZATION_CANCELED;
 220
 221       return (-1);
 222     }
 223 #  endif /* __APPLE__ */
 224
 225     if (http->gssname == GSS_C_NO_NAME)
 226     {
 227       if ((gss_service_name = getenv("CUPS_GSSSERVICENAME")) == NULL)
 228         gss_service_name = CUPS_DEFAULT_GSSSERVICENAME;
 229       else
 230         DEBUG_puts("2cupsDoAuthentication: GSS service name set via "
 231                    "environment variable");
 232
 233       http->gssname = cups_get_gssname(http, gss_service_name);
 234     }
 235
 236 #  ifdef USE_SPNEGO /* We don't implement SPNEGO just yet... */
 237    /*
 238     * Find the start of the Kerberos input token...
 239     */
 240
 241     authorization = httpGetField(http, HTTP_FIELD_WWW_AUTHENTICATE);
 242
 243     authorization += 9;
 244     while (*authorization && _cups_isspace(*authorization))
 245       authorization ++;
 246
 247     if (*authorization)
 248     {
 249      /*
 250       * Decode the authorization string to get the input token...
 251       */
 252
 253       int len = strlen(authorization);
 254
 255       input_token.value  = malloc(len);
 256       input_token.value  = httpDecode64_2(input_token.value, &len,
 257                                           authorization);
 258       input_token.length = len;
 259
 260 #    ifdef DEBUG
 261       {
 262         char *ptr = (char *)input_token.value;
 263         int left = len;
 264
 265         fputs("input_token=", stdout);
 266         while (left > 0)
 267         {
 268           if (*ptr < ' ')
 269             printf("\\%03o", *ptr & 255);
 270           else
 271             putchar(*ptr);
 272           ptr ++;
 273           left --;
 274         }
 275         putchar('\n');
 276       }
 277 #    endif /* DEBUG */
 278     }
 279 #  endif /* USE_SPNEGO */
 280
 281     if (http->gssctx != GSS_C_NO_CONTEXT)
 282     {
 283       gss_delete_sec_context(&minor_status, &http->gssctx, GSS_C_NO_BUFFER);
 284       http->gssctx = GSS_C_NO_CONTEXT;
 285     }
 286
 287     major_status  = gss_init_sec_context(&minor_status, GSS_C_NO_CREDENTIAL,
 288                                          &http->gssctx,
 289                                          http->gssname, http->gssmech,
 290 #ifdef GSS_C_DELEG_POLICY_FLAG
 291                                          GSS_C_DELEG_POLICY_FLAG |
 292 #endif /* GSS_C_DELEG_POLICY_FLAG */
 293                                          GSS_C_MUTUAL_FLAG | GSS_C_INTEG_FLAG,
 294                                          GSS_C_INDEFINITE,
 295                                          GSS_C_NO_CHANNEL_BINDINGS,
 296                                          &input_token, &http->gssmech,
 297                                          &output_token, NULL, NULL);
 298
 299     if (input_token.value)
 300       free(input_token.value);
 301
 302     if (GSS_ERROR(major_status))
 303     {
 304       cups_gss_printf(major_status, minor_status,
 305                       "cupsDoAuthentication: Unable to initialize security "
 306                       "context");
 307       http->status = HTTP_AUTHORIZATION_CANCELED;
 308
 309       return (-1);
 310     }
 311
 312     if (major_status == GSS_S_CONTINUE_NEEDED)
 313       cups_gss_printf(major_status, minor_status,
 314                       "cupsDoAuthentication: Continuation needed!");
 315
 316     if (output_token.length > 0 && output_token.length <= 65536)
 317     {
 318      /*
 319       * Allocate the authorization string since Windows KDCs can have
 320       * arbitrarily large credentials...
 321       */
 322
 323       int authsize = 10 +                               /* "Negotiate " */
 324                      output_token.length * 4 / 3 + 1 +  /* Base64 */
 325                      1;                                 /* nul */
 326
 327       httpSetAuthString(http, NULL, NULL);
 328
 329       if ((http->authstring = malloc(authsize)) == NULL)
 330       {
 331         http->authstring = http->_authstring;
 332         authsize         = sizeof(http->_authstring);
 333       }
 334
 335       strcpy(http->authstring, "Negotiate ");
 336       httpEncode64_2(http->authstring + 10, authsize - 10, output_token.value,
 337                      output_token.length);
 338
 339       gss_release_buffer(&minor_status, &output_token);
 340     }
 341     else
 342     {
 343       DEBUG_printf(("1cupsDoAuthentication: Kerberos credentials too large - "
 344                     "%d bytes!", (int)output_token.length));
 345       http->status = HTTP_AUTHORIZATION_CANCELED;
 346       gss_release_buffer(&minor_status, &output_token);
 347
 348       return (-1);
 349     }
 350 #endif /* HAVE_GSSAPI */
 351   }
 352   else if (strncmp(http->fields[HTTP_FIELD_WWW_AUTHENTICATE], "Digest", 6))
 353   {
 354    /*
 355     * Basic authentication...
 356     */
 357
 358     char        encode[256];            /* Base64 buffer */
 359
 360
 361     httpEncode64_2(encode, sizeof(encode), http->userpass,
 362                    (int)strlen(http->userpass));
 363     httpSetAuthString(http, "Basic", encode);
 364   }
 365   else
 366   {
 367    /*
 368     * Digest authentication...
 369     */
 370
 371     char        encode[33],             /* MD5 buffer */
 372                 digest[1024];           /* Digest auth data */
 373
 374
 375     httpGetSubField(http, HTTP_FIELD_WWW_AUTHENTICATE, "realm", realm);
 376     httpGetSubField(http, HTTP_FIELD_WWW_AUTHENTICATE, "nonce", nonce);
 377
 378     httpMD5(cupsUser(), realm, strchr(http->userpass, ':') + 1, encode);
 379     httpMD5Final(nonce, method, resource, encode);
 380     snprintf(digest, sizeof(digest),
 381              "username=\"%s\", realm=\"%s\", nonce=\"%s\", uri=\"%s\", "
 382              "response=\"%s\"", cupsUser(), realm, nonce, resource, encode);
 383     httpSetAuthString(http, "Digest", digest);
 384   }
 385
 386   DEBUG_printf(("1cupsDoAuthentication: authstring=\"%s\"", http->authstring));
 387
 388   return (0);
 389 }
 390
 391
 392 #ifdef HAVE_GSSAPI
 393 /*
 394  * 'cups_get_gssname()' - Get CUPS service credentials for authentication.
 395  */
 396
 397 static gss_name_t                       /* O - Server name */
 398 cups_get_gssname(
 399     http_t     *http,                   /* I - Connection to server */
 400     const char *service_name)           /* I - Service name */
 401 {
 402   gss_buffer_desc token = GSS_C_EMPTY_BUFFER;
 403                                         /* Service token */
 404   OM_uint32       major_status,         /* Major status code */
 405                   minor_status;         /* Minor status code */
 406   gss_name_t      server_name;          /* Server name */
 407   char            buf[1024],            /* Name buffer */
 408                   fqdn[HTTP_MAX_URI];   /* Server name buffer */
 409
 410
 411   DEBUG_printf(("7cups_get_gssname(http=%p, service_name=\"%s\")", http,
 412                 service_name));
 413
 414
 415  /*
 416   * Get the hostname...
 417   */
 418
 419   httpGetHostname(http, fqdn, sizeof(fqdn));
 420
 421   if (!strcmp(fqdn, "localhost"))
 422     httpGetHostname(NULL, fqdn, sizeof(fqdn));
 423
 424  /*
 425   * Get a server name we can use for authentication purposes...
 426   */
 427
 428   snprintf(buf, sizeof(buf), "%s@%s", service_name, fqdn);
 429
 430   DEBUG_printf(("9cups_get_gssname: Looking up %s...", buf));
 431
 432   token.value  = buf;
 433   token.length = strlen(buf);
 434   server_name  = GSS_C_NO_NAME;
 435   major_status = gss_import_name(&minor_status, &token,
 436                                  GSS_C_NT_HOSTBASED_SERVICE,
 437                                  &server_name);
 438
 439   if (GSS_ERROR(major_status))
 440   {
 441     cups_gss_printf(major_status, minor_status,
 442                     "cups_get_gssname: gss_import_name() failed");
 443     return (NULL);
 444   }
 445
 446   return (server_name);
 447 }
 448
 449
 450 #  ifdef DEBUG
 451 /*
 452  * 'cups_gss_printf()' - Show debug error messages from GSSAPI...
 453  */
 454
 455 static void
 456 cups_gss_printf(OM_uint32  major_status,/* I - Major status code */
 457                 OM_uint32  minor_status,/* I - Minor status code */
 458                 const char *message)    /* I - Prefix for error message */
 459 {
 460   OM_uint32     err_major_status,       /* Major status code for display */
 461                 err_minor_status;       /* Minor status code for display */
 462   OM_uint32     msg_ctx;                /* Message context */
 463   gss_buffer_desc major_status_string = GSS_C_EMPTY_BUFFER,
 464                                         /* Major status message */
 465                 minor_status_string = GSS_C_EMPTY_BUFFER;
 466                                         /* Minor status message */
 467
 468
 469   msg_ctx          = 0;
 470   err_major_status = gss_display_status(&err_minor_status,
 471                                         major_status,
 472                                         GSS_C_GSS_CODE,
 473                                         GSS_C_NO_OID,
 474                                         &msg_ctx,
 475                                         &major_status_string);
 476
 477   if (!GSS_ERROR(err_major_status))
 478     gss_display_status(&err_minor_status, minor_status, GSS_C_MECH_CODE,
 479                        GSS_C_NULL_OID, &msg_ctx, &minor_status_string);
 480
 481   DEBUG_printf(("1%s: %s, %s", message, (char *)major_status_string.value,
 482                 (char *)minor_status_string.value));
 483
 484   gss_release_buffer(&err_minor_status, &major_status_string);
 485   gss_release_buffer(&err_minor_status, &minor_status_string);
 486 }
 487 #  endif /* DEBUG */
 488 #endif /* HAVE_GSSAPI */
 489
 490
 491 /*
 492  * 'cups_local_auth()' - Get the local authorization certificate if
 493  *                       available/applicable...
 494  */
 495
 496 static int                              /* O - 0 if available */
 497                                         /*     1 if not available */
 498                                         /*    -1 error */
 499 cups_local_auth(http_t *http)           /* I - HTTP connection to server */
 500 {
 501 #if defined(WIN32) || defined(__EMX__)
 502  /*
 503   * Currently WIN32 and OS-2 do not support the CUPS server...
 504   */
 505
 506   return (1);
 507 #else
 508   int                   pid;            /* Current process ID */
 509   FILE                  *fp;            /* Certificate file */
 510   char                  trc[16],        /* Try Root Certificate parameter */
 511                         filename[1024], /* Certificate filename */
 512                         certificate[33];/* Certificate string */
 513   _cups_globals_t *cg = _cupsGlobals(); /* Global data */
 514 #  if defined(HAVE_AUTHORIZATION_H)
 515   OSStatus              status;         /* Status */
 516   AuthorizationItem     auth_right;     /* Authorization right */
 517   AuthorizationRights   auth_rights;    /* Authorization rights */
 518   AuthorizationFlags    auth_flags;     /* Authorization flags */
 519   AuthorizationExternalForm auth_extrn; /* Authorization ref external */
 520   char                  auth_key[1024]; /* Buffer */
 521   char                  buffer[1024];   /* Buffer */
 522 #  endif /* HAVE_AUTHORIZATION_H */
 523
 524
 525   DEBUG_printf(("7cups_local_auth(http=%p) hostaddr=%s, hostname=\"%s\"",
 526                 http, httpAddrString(http->hostaddr, filename, sizeof(filename)), http->hostname));
 527
 528  /*
 529   * See if we are accessing localhost...
 530   */
 531
 532   if (!httpAddrLocalhost(http->hostaddr) &&
 533       strcasecmp(http->hostname, "localhost") != 0)
 534   {
 535     DEBUG_puts("8cups_local_auth: Not a local connection!");
 536     return (1);
 537   }
 538
 539 #  if defined(HAVE_AUTHORIZATION_H)
 540  /*
 541   * Delete any previous authorization reference...
 542   */
 543
 544   if (http->auth_ref)
 545   {
 546     AuthorizationFree(http->auth_ref, kAuthorizationFlagDefaults);
 547     http->auth_ref = NULL;
 548   }
 549
 550   if (!getenv("GATEWAY_INTERFACE") &&
 551       httpGetSubField2(http, HTTP_FIELD_WWW_AUTHENTICATE, "authkey",
 552                        auth_key, sizeof(auth_key)))
 553   {
 554     status = AuthorizationCreate(NULL, kAuthorizationEmptyEnvironment,
 555                                  kAuthorizationFlagDefaults, &http->auth_ref);
 556     if (status != errAuthorizationSuccess)
 557     {
 558       DEBUG_printf(("8cups_local_auth: AuthorizationCreate() returned %d (%s)",
 559                     (int)status, cssmErrorString(status)));
 560       return (-1);
 561     }
 562
 563     auth_right.name        = auth_key;
 564     auth_right.valueLength = 0;
 565     auth_right.value       = NULL;
 566     auth_right.flags       = 0;
 567
 568     auth_rights.count = 1;
 569     auth_rights.items = &auth_right;
 570
 571     auth_flags = kAuthorizationFlagDefaults |
 572                  kAuthorizationFlagPreAuthorize |
 573                  kAuthorizationFlagInteractionAllowed |
 574                  kAuthorizationFlagExtendRights;
 575
 576     status = AuthorizationCopyRights(http->auth_ref, &auth_rights,
 577                                      kAuthorizationEmptyEnvironment,
 578                                      auth_flags, NULL);
 579     if (status == errAuthorizationSuccess)
 580       status = AuthorizationMakeExternalForm(http->auth_ref, &auth_extrn);
 581
 582     if (status == errAuthorizationSuccess)
 583     {
 584      /*
 585       * Set the authorization string and return...
 586       */
 587
 588       httpEncode64_2(buffer, sizeof(buffer), (void *)&auth_extrn,
 589                      sizeof(auth_extrn));
 590
 591       httpSetAuthString(http, "AuthRef", buffer);
 592
 593       DEBUG_printf(("8cups_local_auth: Returning authstring=\"%s\"",
 594                     http->authstring));
 595       return (0);
 596     }
 597     else if (status == errAuthorizationCanceled)
 598       return (-1);
 599
 600     DEBUG_printf(("9cups_local_auth: AuthorizationCopyRights() returned %d (%s)",
 601                   (int)status, cssmErrorString(status)));
 602
 603   /*
 604    * Fall through to try certificates...
 605    */
 606   }
 607 #  endif /* HAVE_AUTHORIZATION_H */
 608
 609 #  if defined(SO_PEERCRED) && defined(AF_LOCAL)
 610  /*
 611   * See if we can authenticate using the peer credentials provided over a
 612   * domain socket; if so, specify "PeerCred username" as the authentication
 613   * information...
 614   */
 615
 616 #    ifdef HAVE_GSSAPI
 617   if (strncmp(http->fields[HTTP_FIELD_WWW_AUTHENTICATE], "Negotiate", 9) &&
 618 #    else
 619   if (
 620 #    endif /* HAVE_GSSAPI */
 621       http->hostaddr->addr.sa_family == AF_LOCAL &&
 622       !getenv("GATEWAY_INTERFACE"))     /* Not via CGI programs... */
 623   {
 624    /*
 625     * Verify that the current cupsUser() matches the current UID...
 626     */
 627
 628     struct passwd       *pwd;           /* Password information */
 629     const char          *username;      /* Current username */
 630
 631     username = cupsUser();
 632
 633     if ((pwd = getpwnam(username)) != NULL && pwd->pw_uid == getuid())
 634     {
 635       httpSetAuthString(http, "PeerCred", username);
 636
 637       DEBUG_printf(("8cups_local_auth: Returning authstring=\"%s\"",
 638                     http->authstring));
 639
 640       return (0);
 641     }
 642   }
 643 #  endif /* SO_PEERCRED && AF_LOCAL */
 644
 645  /*
 646   * Try opening a certificate file for this PID.  If that fails,
 647   * try the root certificate...
 648   */
 649
 650   pid = getpid();
 651   snprintf(filename, sizeof(filename), "%s/certs/%d", cg->cups_statedir, pid);
 652   if ((fp = fopen(filename, "r")) == NULL && pid > 0)
 653   {
 654    /*
 655     * No certificate for this PID; see if we can get the root certificate...
 656     */
 657
 658     DEBUG_printf(("9cups_local_auth: Unable to open file %s: %s",
 659                   filename, strerror(errno)));
 660
 661 #ifdef HAVE_GSSAPI
 662     if (!strncmp(http->fields[HTTP_FIELD_WWW_AUTHENTICATE], "Negotiate", 9))
 663     {
 664      /*
 665       * Kerberos required, don't try the root certificate...
 666       */
 667
 668       return (1);
 669     }
 670 #endif /* HAVE_GSSAPI */
 671
 672     if (!httpGetSubField2(http, HTTP_FIELD_WWW_AUTHENTICATE, "trc", trc,
 673                           sizeof(trc)))
 674     {
 675      /*
 676       * Scheduler doesn't want us to use the root certificate...
 677       */
 678
 679       return (1);
 680     }
 681
 682     snprintf(filename, sizeof(filename), "%s/certs/0", cg->cups_statedir);
 683     fp = fopen(filename, "r");
 684   }
 685
 686   if (fp)
 687   {
 688    /*
 689     * Read the certificate from the file...
 690     */
 691
 692     fgets(certificate, sizeof(certificate), fp);
 693     fclose(fp);
 694
 695    /*
 696     * Set the authorization string and return...
 697     */
 698
 699     httpSetAuthString(http, "Local", certificate);
 700
 701     DEBUG_printf(("8cups_local_auth: Returning authstring=\"%s\"",
 702                   http->authstring));
 703
 704     return (0);
 705   }
 706
 707   return (1);
 708 #endif /* WIN32 || __EMX__ */
 709 }
 710
 711
 712 /*
 713  * End of "$Id: auth.c 7720 2008-07-11 22:46:21Z mike $".
 714  */