cups/auth.c

   1 /*
   2  * "$Id: auth.c 7720 2008-07-11 22:46:21Z mike $"
   3  *
   4  *   Authentication functions for the Common UNIX Printing System (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 "globals.h"
  34 #include "debug.h"
  35 #include <stdlib.h>
  36 #include <ctype.h>
  37 #include <errno.h>
  38 #include <fcntl.h>
  39 #include <sys/stat.h>
  40 #if defined(WIN32) || defined(__EMX__)
  41 #  include <io.h>
  42 #else
  43 #  include <unistd.h>
  44 #endif /* WIN32 || __EMX__ */
  45
  46 #if HAVE_AUTHORIZATION_H
  47 #  include <Security/Authorization.h>
  48 #  ifdef HAVE_SECBASEPRIV_H
  49 #    include <Security/SecBasePriv.h>
  50 #  else
  51 extern const char *cssmErrorString(int error);
  52 #  endif /* HAVE_SECBASEPRIV_H */
  53 #endif /* HAVE_AUTHORIZATION_H */
  54
  55 #if defined(SO_PEERCRED) && defined(AF_LOCAL)
  56 #  include <pwd.h>
  57 #endif /* SO_PEERCRED && AF_LOCAL */
  58
  59
  60 /*
  61  * Local functions...
  62  */
  63
  64 #ifdef HAVE_GSSAPI
  65 static gss_name_t cups_get_gssname(http_t *http, const char *service_name);
  66 #  ifdef DEBUG
  67 static void     cups_gss_printf(OM_uint32 major_status, OM_uint32 minor_status,
  68                                 const char *message);
  69 #  else
  70 #    define     cups_gss_printf(major, minor, message)
  71 #  endif /* DEBUG */
  72 #endif /* HAVE_GSSAPI */
  73 static int      cups_local_auth(http_t *http);
  74
  75
  76 /*
  77  * 'cupsDoAuthentication()' - Authenticate a request.
  78  *
  79  * This function should be called in response to a @code HTTP_UNAUTHORIZED@
  80  * status, prior to resubmitting your request.
  81  *
  82  * @since CUPS 1.1.20/Mac OS X 10.4@
  83  */
  84
  85 int                                     /* O - 0 on success, -1 on error */
  86 cupsDoAuthentication(
  87     http_t     *http,                   /* I - Connection to server or @code CUPS_HTTP_DEFAULT@ */
  88     const char *method,                 /* I - Request method ("GET", "POST", "PUT") */
  89     const char *resource)               /* I - Resource path */
  90 {
  91   const char    *password;              /* Password string */
  92   char          prompt[1024],           /* Prompt for user */
  93                 realm[HTTP_MAX_VALUE],  /* realm="xyz" string */
  94                 nonce[HTTP_MAX_VALUE];  /* nonce="xyz" string */
  95   int           localauth;              /* Local authentication result */
  96   _cups_globals_t *cg;                  /* Global data */
  97
  98
  99   DEBUG_printf(("cupsDoAuthentication(http=%p, method=\"%s\", resource=\"%s\")",
 100                 http, method, resource));
 101
 102   if (!http)
 103     http = _cupsConnect();
 104
 105   if (!http || !method || !resource)
 106     return (-1);
 107
 108   DEBUG_printf(("2cupsDoAuthentication: digest_tries=%d, userpass=\"%s\"",
 109                 http->digest_tries, http->userpass));
 110   DEBUG_printf(("2cupsDoAuthentication: WWW-Authenticate=\"%s\"",
 111                 httpGetField(http, HTTP_FIELD_WWW_AUTHENTICATE)));
 112
 113  /*
 114   * Clear the current authentication string...
 115   */
 116
 117   httpSetAuthString(http, NULL, NULL);
 118
 119  /*
 120   * See if we can do local authentication...
 121   */
 122
 123   if (http->digest_tries < 3)
 124   {
 125     if ((localauth = cups_local_auth(http)) == 0)
 126     {
 127       DEBUG_printf(("2cupsDoAuthentication: authstring=\"%s\"",
 128                     http->authstring));
 129
 130       if (http->status == HTTP_UNAUTHORIZED)
 131         http->digest_tries ++;
 132
 133       return (0);
 134     }
 135     else if (localauth == -1)
 136     {
 137       http->status = HTTP_AUTHORIZATION_CANCELED;
 138       return (-1);                      /* Error or canceled */
 139     }
 140   }
 141
 142  /*
 143   * Nope, see if we should retry the current username:password...
 144   */
 145
 146   if ((http->digest_tries > 1 || !http->userpass[0]) &&
 147       strncmp(http->fields[HTTP_FIELD_WWW_AUTHENTICATE], "Negotiate", 9))
 148   {
 149    /*
 150     * Nope - get a new password from the user...
 151     */
 152
 153     cg = _cupsGlobals();
 154
 155     if (!cg->lang_default)
 156       cg->lang_default = cupsLangDefault();
 157
 158     snprintf(prompt, sizeof(prompt),
 159              _cupsLangString(cg->lang_default, _("Password for %s on %s? ")),
 160              cupsUser(),
 161              http->hostname[0] == '/' ? "localhost" : http->hostname);
 162
 163     http->digest_tries  = strncasecmp(http->fields[HTTP_FIELD_WWW_AUTHENTICATE],
 164                                       "Digest", 5) != 0;
 165     http->userpass[0]   = '\0';
 166
 167     if ((password = cupsGetPassword2(prompt, http, method, resource)) == NULL)
 168     {
 169       http->status = HTTP_AUTHORIZATION_CANCELED;
 170       return (-1);
 171     }
 172
 173     if (!password[0])
 174     {
 175       http->status = HTTP_AUTHORIZATION_CANCELED;
 176       return (-1);
 177     }
 178
 179     snprintf(http->userpass, sizeof(http->userpass), "%s:%s", cupsUser(),
 180              password);
 181   }
 182   else if (http->status == HTTP_UNAUTHORIZED)
 183     http->digest_tries ++;
 184
 185   if (http->status == HTTP_UNAUTHORIZED && http->digest_tries >= 3)
 186   {
 187     DEBUG_printf(("1cupsDoAuthentication: Too many authentication tries (%d)",
 188                   http->digest_tries));
 189
 190     http->status = HTTP_AUTHORIZATION_CANCELED;
 191     return (-1);
 192   }
 193
 194  /*
 195   * Got a password; encode it for the server...
 196   */
 197
 198   if (!strncmp(http->fields[HTTP_FIELD_WWW_AUTHENTICATE], "Negotiate", 9))
 199   {
 200 #ifdef HAVE_GSSAPI
 201    /*
 202     * Kerberos authentication...
 203     */
 204
 205     OM_uint32           minor_status,   /* Minor status code */
 206                         major_status;   /* Major status code */
 207     gss_buffer_desc     output_token = GSS_C_EMPTY_BUFFER,
 208                                         /* Output token */
 209                         input_token = GSS_C_EMPTY_BUFFER;
 210                                         /* Input token */
 211     char                *gss_service_name;
 212                                         /* GSS service name */
 213 #  ifdef USE_SPNEGO
 214     const char          *authorization;
 215                                         /* Pointer into Authorization string */
 216 #  endif /* USE_SPNEGO */
 217
 218
 219 #  ifdef __APPLE__
 220    /*
 221     * If the weak-linked GSSAPI/Kerberos library is not present, don't try
 222     * to use it...
 223     */
 224
 225     if (gss_init_sec_context == NULL)
 226     {
 227       DEBUG_puts("1cupsDoAuthentication: Weak-linked GSSAPI/Kerberos framework "
 228                  "is not present");
 229       http->status = HTTP_AUTHORIZATION_CANCELED;
 230
 231       return (-1);
 232     }
 233 #  endif /* __APPLE__ */
 234
 235     if (http->gssname == GSS_C_NO_NAME)
 236     {
 237       if ((gss_service_name = getenv("CUPS_GSSSERVICENAME")) == NULL)
 238         gss_service_name = CUPS_DEFAULT_GSSSERVICENAME;
 239       else
 240         DEBUG_puts("2cupsDoAuthentication: GSS service name set via "
 241                    "environment variable");
 242
 243       http->gssname = cups_get_gssname(http, gss_service_name);
 244     }
 245
 246 #  ifdef USE_SPNEGO /* We don't implement SPNEGO just yet... */
 247    /*
 248     * Find the start of the Kerberos input token...
 249     */
 250
 251     authorization = httpGetField(http, HTTP_FIELD_WWW_AUTHENTICATE);
 252
 253     authorization += 9;
 254     while (*authorization && isspace(*authorization & 255))
 255       authorization ++;
 256
 257     if (*authorization)
 258     {
 259      /*
 260       * Decode the authorization string to get the input token...
 261       */
 262
 263       int len = strlen(authorization);
 264
 265       input_token.value  = malloc(len);
 266       input_token.value  = httpDecode64_2(input_token.value, &len,
 267                                           authorization);
 268       input_token.length = len;
 269
 270 #    ifdef DEBUG
 271       {
 272         char *ptr = (char *)input_token.value;
 273         int left = len;
 274
 275         fputs("input_token=", stdout);
 276         while (left > 0)
 277         {
 278           if (*ptr < ' ')
 279             printf("\\%03o", *ptr & 255);
 280           else
 281             putchar(*ptr);
 282           ptr ++;
 283           left --;
 284         }
 285         putchar('\n');
 286       }
 287 #    endif /* DEBUG */
 288     }
 289 #  endif /* USE_SPNEGO */
 290
 291     if (http->gssctx != GSS_C_NO_CONTEXT)
 292     {
 293       gss_delete_sec_context(&minor_status, &http->gssctx, GSS_C_NO_BUFFER);
 294       http->gssctx = GSS_C_NO_CONTEXT;
 295     }
 296
 297     major_status  = gss_init_sec_context(&minor_status, GSS_C_NO_CREDENTIAL,
 298                                          &http->gssctx,
 299                                          http->gssname, http->gssmech,
 300 #ifdef GSS_C_DELEG_POLICY_FLAG
 301                                          GSS_C_DELEG_POLICY_FLAG |
 302 #endif /* GSS_C_DELEG_POLICY_FLAG */
 303                                          GSS_C_MUTUAL_FLAG | GSS_C_INTEG_FLAG,
 304                                          GSS_C_INDEFINITE,
 305                                          GSS_C_NO_CHANNEL_BINDINGS,
 306                                          &input_token, &http->gssmech,
 307                                          &output_token, NULL, NULL);
 308
 309     if (input_token.value)
 310       free(input_token.value);
 311
 312     if (GSS_ERROR(major_status))
 313     {
 314       cups_gss_printf(major_status, minor_status,
 315                       "cupsDoAuthentication: Unable to initialize security "
 316                       "context");
 317       http->status = HTTP_AUTHORIZATION_CANCELED;
 318
 319       return (-1);
 320     }
 321
 322     if (major_status == GSS_S_CONTINUE_NEEDED)
 323       cups_gss_printf(major_status, minor_status,
 324                       "cupsDoAuthentication: Continuation needed!");
 325
 326     if (output_token.length > 0 && output_token.length <= 65536)
 327     {
 328      /*
 329       * Allocate the authorization string since Windows KDCs can have
 330       * arbitrarily large credentials...
 331       */
 332
 333       int authsize = 10 +                               /* "Negotiate " */
 334                      output_token.length * 4 / 3 + 1 +  /* Base64 */
 335                      1;                                 /* nul */
 336
 337       httpSetAuthString(http, NULL, NULL);
 338
 339       if ((http->authstring = malloc(authsize)) == NULL)
 340       {
 341         http->authstring = http->_authstring;
 342         authsize         = sizeof(http->_authstring);
 343       }
 344
 345       strcpy(http->authstring, "Negotiate ");
 346       httpEncode64_2(http->authstring + 10, authsize - 10, output_token.value,
 347                      output_token.length);
 348
 349       gss_release_buffer(&minor_status, &output_token);
 350     }
 351     else
 352     {
 353       DEBUG_printf(("1cupsDoAuthentication: Kerberos credentials too large - "
 354                     "%d bytes!", (int)output_token.length));
 355       http->status = HTTP_AUTHORIZATION_CANCELED;
 356       gss_release_buffer(&minor_status, &output_token);
 357
 358       return (-1);
 359     }
 360 #endif /* HAVE_GSSAPI */
 361   }
 362   else if (strncmp(http->fields[HTTP_FIELD_WWW_AUTHENTICATE], "Digest", 6))
 363   {
 364    /*
 365     * Basic authentication...
 366     */
 367
 368     char        encode[256];            /* Base64 buffer */
 369
 370
 371     httpEncode64_2(encode, sizeof(encode), http->userpass,
 372                    (int)strlen(http->userpass));
 373     httpSetAuthString(http, "Basic", encode);
 374   }
 375   else
 376   {
 377    /*
 378     * Digest authentication...
 379     */
 380
 381     char        encode[33],             /* MD5 buffer */
 382                 digest[1024];           /* Digest auth data */
 383
 384
 385     httpGetSubField(http, HTTP_FIELD_WWW_AUTHENTICATE, "realm", realm);
 386     httpGetSubField(http, HTTP_FIELD_WWW_AUTHENTICATE, "nonce", nonce);
 387
 388     httpMD5(cupsUser(), realm, strchr(http->userpass, ':') + 1, encode);
 389     httpMD5Final(nonce, method, resource, encode);
 390     snprintf(digest, sizeof(digest),
 391              "username=\"%s\", realm=\"%s\", nonce=\"%s\", uri=\"%s\", "
 392              "response=\"%s\"", cupsUser(), realm, nonce, resource, encode);
 393     httpSetAuthString(http, "Digest", digest);
 394   }
 395
 396   DEBUG_printf(("1cupsDoAuthentication: authstring=\"%s\"", http->authstring));
 397
 398   return (0);
 399 }
 400
 401
 402 #ifdef HAVE_GSSAPI
 403 /*
 404  * 'cups_get_gssname()' - Get CUPS service credentials for authentication.
 405  */
 406
 407 static gss_name_t                       /* O - Server name */
 408 cups_get_gssname(
 409     http_t     *http,                   /* I - Connection to server */
 410     const char *service_name)           /* I - Service name */
 411 {
 412   gss_buffer_desc token = GSS_C_EMPTY_BUFFER;
 413                                         /* Service token */
 414   OM_uint32       major_status,         /* Major status code */
 415                   minor_status;         /* Minor status code */
 416   gss_name_t      server_name;          /* Server name */
 417   char            buf[1024],            /* Name buffer */
 418                   fqdn[HTTP_MAX_URI];   /* Server name buffer */
 419
 420
 421   DEBUG_printf(("7cups_get_gssname(http=%p, service_name=\"%s\")", http,
 422                 service_name));
 423
 424
 425  /*
 426   * Get the hostname...
 427   */
 428
 429   httpGetHostname(http, fqdn, sizeof(fqdn));
 430
 431   if (!strcmp(fqdn, "localhost"))
 432     httpGetHostname(NULL, fqdn, sizeof(fqdn));
 433
 434  /*
 435   * Get a server name we can use for authentication purposes...
 436   */
 437
 438   snprintf(buf, sizeof(buf), "%s@%s", service_name, fqdn);
 439
 440   DEBUG_printf(("9cups_get_gssname: Looking up %s...", buf));
 441
 442   token.value  = buf;
 443   token.length = strlen(buf);
 444   server_name  = GSS_C_NO_NAME;
 445   major_status = gss_import_name(&minor_status, &token,
 446                                  GSS_C_NT_HOSTBASED_SERVICE,
 447                                  &server_name);
 448
 449   if (GSS_ERROR(major_status))
 450   {
 451     cups_gss_printf(major_status, minor_status,
 452                     "cups_get_gssname: gss_import_name() failed");
 453     return (NULL);
 454   }
 455
 456   return (server_name);
 457 }
 458
 459
 460 #  ifdef DEBUG
 461 /*
 462  * 'cups_gss_printf()' - Show debug error messages from GSSAPI...
 463  */
 464
 465 static void
 466 cups_gss_printf(OM_uint32  major_status,/* I - Major status code */
 467                 OM_uint32  minor_status,/* I - Minor status code */
 468                 const char *message)    /* I - Prefix for error message */
 469 {
 470   OM_uint32     err_major_status,       /* Major status code for display */
 471                 err_minor_status;       /* Minor status code for display */
 472   OM_uint32     msg_ctx;                /* Message context */
 473   gss_buffer_desc major_status_string = GSS_C_EMPTY_BUFFER,
 474                                         /* Major status message */
 475                 minor_status_string = GSS_C_EMPTY_BUFFER;
 476                                         /* Minor status message */
 477
 478
 479   msg_ctx          = 0;
 480   err_major_status = gss_display_status(&err_minor_status,
 481                                         major_status,
 482                                         GSS_C_GSS_CODE,
 483                                         GSS_C_NO_OID,
 484                                         &msg_ctx,
 485                                         &major_status_string);
 486
 487   if (!GSS_ERROR(err_major_status))
 488     gss_display_status(&err_minor_status, minor_status, GSS_C_MECH_CODE,
 489                        GSS_C_NULL_OID, &msg_ctx, &minor_status_string);
 490
 491   DEBUG_printf(("1%s: %s, %s", message, (char *)major_status_string.value,
 492                 (char *)minor_status_string.value));
 493
 494   gss_release_buffer(&err_minor_status, &major_status_string);
 495   gss_release_buffer(&err_minor_status, &minor_status_string);
 496 }
 497 #  endif /* DEBUG */
 498 #endif /* HAVE_GSSAPI */
 499
 500
 501 /*
 502  * 'cups_local_auth()' - Get the local authorization certificate if
 503  *                       available/applicable...
 504  */
 505
 506 static int                              /* O - 0 if available */
 507                                         /*     1 if not available */
 508                                         /*    -1 error */
 509 cups_local_auth(http_t *http)           /* I - HTTP connection to server */
 510 {
 511 #if defined(WIN32) || defined(__EMX__)
 512  /*
 513   * Currently WIN32 and OS-2 do not support the CUPS server...
 514   */
 515
 516   return (1);
 517 #else
 518   int                   pid;            /* Current process ID */
 519   FILE                  *fp;            /* Certificate file */
 520   char                  trc[16],        /* Try Root Certificate parameter */
 521                         filename[1024], /* Certificate filename */
 522                         certificate[33];/* Certificate string */
 523   _cups_globals_t *cg = _cupsGlobals(); /* Global data */
 524 #  if defined(HAVE_AUTHORIZATION_H)
 525   OSStatus              status;         /* Status */
 526   AuthorizationItem     auth_right;     /* Authorization right */
 527   AuthorizationRights   auth_rights;    /* Authorization rights */
 528   AuthorizationFlags    auth_flags;     /* Authorization flags */
 529   AuthorizationExternalForm auth_extrn; /* Authorization ref external */
 530   char                  auth_key[1024]; /* Buffer */
 531   char                  buffer[1024];   /* Buffer */
 532 #  endif /* HAVE_AUTHORIZATION_H */
 533
 534
 535   DEBUG_printf(("7cups_local_auth(http=%p) hostaddr=%s, hostname=\"%s\"",
 536                 http, httpAddrString(http->hostaddr, filename, sizeof(filename)), http->hostname));
 537
 538  /*
 539   * See if we are accessing localhost...
 540   */
 541
 542   if (!httpAddrLocalhost(http->hostaddr) &&
 543       strcasecmp(http->hostname, "localhost") != 0)
 544   {
 545     DEBUG_puts("8cups_local_auth: Not a local connection!");
 546     return (1);
 547   }
 548
 549 #  if defined(HAVE_AUTHORIZATION_H)
 550  /*
 551   * Delete any previous authorization reference...
 552   */
 553
 554   if (http->auth_ref)
 555   {
 556     AuthorizationFree(http->auth_ref, kAuthorizationFlagDefaults);
 557     http->auth_ref = NULL;
 558   }
 559
 560   if (!getenv("GATEWAY_INTERFACE") &&
 561       httpGetSubField2(http, HTTP_FIELD_WWW_AUTHENTICATE, "authkey",
 562                        auth_key, sizeof(auth_key)))
 563   {
 564     status = AuthorizationCreate(NULL, kAuthorizationEmptyEnvironment,
 565                                  kAuthorizationFlagDefaults, &http->auth_ref);
 566     if (status != errAuthorizationSuccess)
 567     {
 568       DEBUG_printf(("8cups_local_auth: AuthorizationCreate() returned %d (%s)",
 569                     (int)status, cssmErrorString(status)));
 570       return (-1);
 571     }
 572
 573     auth_right.name        = auth_key;
 574     auth_right.valueLength = 0;
 575     auth_right.value       = NULL;
 576     auth_right.flags       = 0;
 577
 578     auth_rights.count = 1;
 579     auth_rights.items = &auth_right;
 580
 581     auth_flags = kAuthorizationFlagDefaults |
 582                  kAuthorizationFlagPreAuthorize |
 583                  kAuthorizationFlagInteractionAllowed |
 584                  kAuthorizationFlagExtendRights;
 585
 586     status = AuthorizationCopyRights(http->auth_ref, &auth_rights,
 587                                      kAuthorizationEmptyEnvironment,
 588                                      auth_flags, NULL);
 589     if (status == errAuthorizationSuccess)
 590       status = AuthorizationMakeExternalForm(http->auth_ref, &auth_extrn);
 591
 592     if (status == errAuthorizationSuccess)
 593     {
 594      /*
 595       * Set the authorization string and return...
 596       */
 597
 598       httpEncode64_2(buffer, sizeof(buffer), (void *)&auth_extrn,
 599                      sizeof(auth_extrn));
 600
 601       httpSetAuthString(http, "AuthRef", buffer);
 602
 603       DEBUG_printf(("8cups_local_auth: Returning authstring=\"%s\"",
 604                     http->authstring));
 605       return (0);
 606     }
 607     else if (status == errAuthorizationCanceled)
 608       return (-1);
 609
 610     DEBUG_printf(("9cups_local_auth: AuthorizationCopyRights() returned %d (%s)",
 611                   (int)status, cssmErrorString(status)));
 612
 613   /*
 614    * Fall through to try certificates...
 615    */
 616   }
 617 #  endif /* HAVE_AUTHORIZATION_H */
 618
 619 #  if defined(SO_PEERCRED) && defined(AF_LOCAL)
 620  /*
 621   * See if we can authenticate using the peer credentials provided over a
 622   * domain socket; if so, specify "PeerCred username" as the authentication
 623   * information...
 624   */
 625
 626 #    ifdef HAVE_GSSAPI
 627   if (strncmp(http->fields[HTTP_FIELD_WWW_AUTHENTICATE], "Negotiate", 9) &&
 628 #    else
 629   if (
 630 #    endif /* HAVE_GSSAPI */
 631       http->hostaddr->addr.sa_family == AF_LOCAL &&
 632       !getenv("GATEWAY_INTERFACE"))     /* Not via CGI programs... */
 633   {
 634    /*
 635     * Verify that the current cupsUser() matches the current UID...
 636     */
 637
 638     struct passwd       *pwd;           /* Password information */
 639     const char          *username;      /* Current username */
 640
 641     username = cupsUser();
 642
 643     if ((pwd = getpwnam(username)) != NULL && pwd->pw_uid == getuid())
 644     {
 645       httpSetAuthString(http, "PeerCred", username);
 646
 647       DEBUG_printf(("8cups_local_auth: Returning authstring=\"%s\"",
 648                     http->authstring));
 649
 650       return (0);
 651     }
 652   }
 653 #  endif /* SO_PEERCRED && AF_LOCAL */
 654
 655  /*
 656   * Try opening a certificate file for this PID.  If that fails,
 657   * try the root certificate...
 658   */
 659
 660   pid = getpid();
 661   snprintf(filename, sizeof(filename), "%s/certs/%d", cg->cups_statedir, pid);
 662   if ((fp = fopen(filename, "r")) == NULL && pid > 0)
 663   {
 664    /*
 665     * No certificate for this PID; see if we can get the root certificate...
 666     */
 667
 668     DEBUG_printf(("9cups_local_auth: Unable to open file %s: %s",
 669                   filename, strerror(errno)));
 670
 671 #ifdef HAVE_GSSAPI
 672     if (!strncmp(http->fields[HTTP_FIELD_WWW_AUTHENTICATE], "Negotiate", 9))
 673     {
 674      /*
 675       * Kerberos required, don't try the root certificate...
 676       */
 677
 678       return (1);
 679     }
 680 #endif /* HAVE_GSSAPI */
 681
 682     if (!httpGetSubField2(http, HTTP_FIELD_WWW_AUTHENTICATE, "trc", trc,
 683                           sizeof(trc)))
 684     {
 685      /*
 686       * Scheduler doesn't want us to use the root certificate...
 687       */
 688
 689       return (1);
 690     }
 691
 692     snprintf(filename, sizeof(filename), "%s/certs/0", cg->cups_statedir);
 693     fp = fopen(filename, "r");
 694   }
 695
 696   if (fp)
 697   {
 698    /*
 699     * Read the certificate from the file...
 700     */
 701
 702     fgets(certificate, sizeof(certificate), fp);
 703     fclose(fp);
 704
 705    /*
 706     * Set the authorization string and return...
 707     */
 708
 709     httpSetAuthString(http, "Local", certificate);
 710
 711     DEBUG_printf(("8cups_local_auth: Returning authstring=\"%s\"",
 712                   http->authstring));
 713
 714     return (0);
 715   }
 716
 717   return (1);
 718 #endif /* WIN32 || __EMX__ */
 719 }
 720
 721
 722 /*
 723  * End of "$Id: auth.c 7720 2008-07-11 22:46:21Z mike $".
 724  */