//

// Authentication functions for CUPS.

//

// Copyright © 2020-2025 by OpenPrinting.

// Copyright © 2007-2019 by Apple Inc.

// Copyright © 1997-2007 by Easy Software Products.

//

// This file contains Kerberos support code, copyright 2006 by

// Jelmer Vernooij.

//

// Licensed under Apache License v2.0.  See the file "LICENSE" for more

// information.

//

#include "cups-private.h"

#include "debug-internal.h"

#include <fcntl.h>

#include <sys/stat.h>

#if defined(_WIN32) || defined(__EMX__)

#  include <io.h>

#else

#  include <unistd.h>

#endif // _WIN32 || __EMX__

#if HAVE_AUTHORIZATION_H

#  include <Security/Authorization.h>

#endif // HAVE_AUTHORIZATION_H

#if defined(SO_PEERCRED) && defined(AF_LOCAL)

#  include <pwd.h>

#endif // SO_PEERCRED && AF_LOCAL

//

// Local functions...

//

static const char *cups_auth_find(const char *www_authenticate, const char *scheme);

static const char *cups_auth_param(const char *scheme, const char *name, char *value, size_t valsize);

static const char *cups_auth_scheme(const char *www_authenticate, char *scheme, size_t schemesize);

static bool   cups_do_local_auth(http_t *http);

#ifdef HAVE_GSSAPI

#  define CUPS_GSS_OK 0   // Successfully set credentials

#  define CUPS_GSS_NONE -1    // No credentials

#  define CUPS_GSS_FAIL -2    // Failed credentials/authentication

#  ifdef HAVE_GSS_ACQUIRE_CRED_EX_F

#    ifdef HAVE_GSS_GSSAPI_SPI_H

#      include <GSS/gssapi_spi.h>

#    else

#      define GSS_AUTH_IDENTITY_TYPE_1 1

#      define gss_acquire_cred_ex_f __ApplePrivate_gss_acquire_cred_ex_f

typedef struct gss_auth_identity // @private@

{

  uint32_t type;

  uint32_t flags;

  char *username;

  char *realm;

  char *password;

  gss_buffer_t *credentialsRef;

} gss_auth_identity_desc;

extern OM_uint32 gss_acquire_cred_ex_f(gss_status_id_t, const gss_name_t,

               OM_uint32, OM_uint32, const gss_OID,

               gss_cred_usage_t, gss_auth_identity_t,

               void *, void (*)(void *, OM_uint32,

                                gss_status_id_t,

              gss_cred_id_t,

              gss_OID_set,

              OM_uint32));

#    endif // HAVE_GSS_GSSAPI_SPI_H

#    include <dispatch/dispatch.h>

typedef struct _cups_gss_acquire_s  // Acquire callback data

{

  dispatch_semaphore_t  sem;    // Synchronization semaphore

  OM_uint32   major;    // Returned status code

  gss_cred_id_t   creds;    // Returned credentials

} _cups_gss_acquire_t;

static void cups_gss_acquire(void *ctx, OM_uint32 major,

                     gss_status_id_t status,

         gss_cred_id_t creds, gss_OID_set oids,

         OM_uint32 time_rec);

#  endif // HAVE_GSS_ACQUIRE_CRED_EX_F

static gss_name_t cups_gss_getname(http_t *http, const char *service_name);

#  ifdef DEBUG

static void cups_gss_printf(OM_uint32 major_status, OM_uint32 minor_status,

        const char *message);

#  else

#    define cups_gss_printf(major, minor, message)

#  endif // DEBUG

#endif // HAVE_GSSAPI

//

// 'cupsDoAuthentication()' - Authenticate a request.

//

// This function performs authentication for a request.  It should be called in

// response to a `HTTP_STATUS_UNAUTHORIZED` status, prior to resubmitting your

// request.

//

// @since CUPS 1.1.20@

//

int         // O - `0` on success, `-1` on error

cupsDoAuthentication(

    http_t     *http,     // I - Connection to server or `CUPS_HTTP_DEFAULT`

    const char *method,     // I - Request method ("GET", "POST", "PUT")

    const char *resource)   // I - Resource path

{

  const char  *password,    // Password string

    *www_auth,    // WWW-Authenticate header

    *schemedata;    // Scheme-specific data

  char    scheme[256],    // Scheme name

    prompt[1024];   // Prompt for user

  _cups_globals_t *cg = _cupsGlobals(); // Global data

  DEBUG_printf("cupsDoAuthentication(http=%p, method=\"%s\", resource=\"%s\")", (void *)http, method, resource);

  // Range check input...

  if (!http)

    http = _cupsConnect();

  if (!http || !method || !resource)

    return (-1);

  DEBUG_printf("2cupsDoAuthentication: digest_tries=%d, userpass=\"%s\"", http->digest_tries, http->userpass);

  DEBUG_printf("2cupsDoAuthentication: WWW-Authenticate=\"%s\"", httpGetField(http, HTTP_FIELD_WWW_AUTHENTICATE));

  // Clear the current authentication string...

  httpSetAuthString(http, NULL, NULL);

  // See if we can do local authentication...

  if (http->digest_tries < 3)

  {

    if (cups_do_local_auth(http))

    {

      DEBUG_printf("2cupsDoAuthentication: authstring=\"%s\"", http->authstring);

      if (http->status == HTTP_STATUS_UNAUTHORIZED)

  http->digest_tries ++;

      return (0);

    }

  }

  // Nope, loop through the authentication schemes to find the first we support.

  www_auth = httpGetField(http, HTTP_FIELD_WWW_AUTHENTICATE);

  for (schemedata = cups_auth_scheme(www_auth, scheme, sizeof(scheme)); schemedata; schemedata = cups_auth_scheme(schemedata + strlen(scheme), scheme, sizeof(scheme)))

  {

    // Check the scheme name...

    DEBUG_printf("2cupsDoAuthentication: Trying scheme \"%s\"...", scheme);

#ifdef HAVE_GSSAPI

    if (!_cups_strcasecmp(scheme, "Negotiate") && !httpAddrIsLocalhost(httpGetAddress(http)))

    {

      // Kerberos authentication to remote server...

      int gss_status;     // Auth status

      if ((gss_status = _cupsSetNegotiateAuthString(http, method, resource)) == CUPS_GSS_FAIL)

      {

        DEBUG_puts("1cupsDoAuthentication: Negotiate failed.");

  http->status = HTTP_STATUS_CUPS_AUTHORIZATION_CANCELED;

  return (-1);

      }

      else if (gss_status == CUPS_GSS_NONE)

      {

        DEBUG_puts("2cupsDoAuthentication: No credentials for Negotiate.");

        continue;

      }

      else

      {

        DEBUG_puts("2cupsDoAuthentication: Using Negotiate.");

        break;

      }

    }

    else

#endif // HAVE_GSSAPI

    if (!_cups_strcasecmp(scheme, "Bearer"))

    {

      // OAuth 2.0 (Bearer) authentication...

      const char  *bearer = NULL; // Bearer token string, if any

      if (cg->oauth_cb)

      {

        // Try callback...

  char  scope[HTTP_MAX_VALUE];  // scope="xyz" string

  cups_auth_param(schemedata, "realm", http->realm, sizeof(http->realm));

  if (cups_auth_param(schemedata, "scope", scope, sizeof(scope)))

    bearer = (cg->oauth_cb)(http, http->realm, scope, resource, cg->oauth_data);

  else

    bearer = (cg->oauth_cb)(http, http->realm, NULL, resource, cg->oauth_data);

      }

      if (bearer)

      {

        // Use this access token...

        httpSetAuthString(http, "Bearer", bearer);

        break;

      }

      else

      {

        // No access token, try the next scheme...

        DEBUG_puts("2cupsDoAuthentication: No OAuth access token to provide.");

        continue;

      }

    }

    else if (_cups_strcasecmp(scheme, "Basic") && _cups_strcasecmp(scheme, "Digest") && _cups_strcasecmp(scheme, "Negotiate"))

    {

      // Other schemes not yet supported...

      DEBUG_printf("2cupsDoAuthentication: Scheme \"%s\" not yet supported.", scheme);

      continue;

    }

    // See if we should retry the current username:password...

    if (http->digest_tries > 1 || !http->userpass[0])

    {

      // Nope - get a new password from the user...

      char default_username[HTTP_MAX_VALUE];

          // Default username

      if (!cg->lang_default)

  cg->lang_default = cupsLangDefault();

      if (cups_auth_param(schemedata, "username", default_username, sizeof(default_username)))

  cupsSetUser(default_username);

      snprintf(prompt, sizeof(prompt), _cupsLangString(cg->lang_default, _("Password for %s on %s? ")), cupsGetUser(), http->hostname[0] == '/' ? "localhost" : http->hostname);

      http->digest_tries = _cups_strncasecmp(scheme, "Digest", 6) != 0;

      http->userpass[0]  = '\0';

      if ((password = cupsGetPassword2(prompt, http, method, resource)) == NULL)

      {

        DEBUG_puts("1cupsDoAuthentication: User canceled password request.");

  http->status = HTTP_STATUS_CUPS_AUTHORIZATION_CANCELED;

  return (-1);

      }

      snprintf(http->userpass, sizeof(http->userpass), "%s:%s", cupsGetUser(), password);

    }

    else if (http->status == HTTP_STATUS_UNAUTHORIZED)

    {

      http->digest_tries ++;

    }

    if (http->status == HTTP_STATUS_UNAUTHORIZED && http->digest_tries >= 3)

    {

      DEBUG_printf("1cupsDoAuthentication: Too many authentication tries (%d)", http->digest_tries);

      http->status = HTTP_STATUS_CUPS_AUTHORIZATION_CANCELED;

      return (-1);

    }

    // Got a password; encode it for the server...

    if (!_cups_strcasecmp(scheme, "Basic"))

    {

      // Basic authentication...

      char  encode[256];    // Base64 buffer

      DEBUG_puts("2cupsDoAuthentication: Using Basic.");

      httpEncode64_3(encode, sizeof(encode), http->userpass, strlen(http->userpass), false);

      httpSetAuthString(http, "Basic", encode);

      break;

    }

    else if (!_cups_strcasecmp(scheme, "Digest"))

    {

      // Digest authentication...

      char nonce[HTTP_MAX_VALUE]; // nonce="xyz" string

      cups_auth_param(schemedata, "algorithm", http->algorithm, sizeof(http->algorithm));

      cups_auth_param(schemedata, "nonce", nonce, sizeof(nonce));

      cups_auth_param(schemedata, "opaque", http->opaque, sizeof(http->opaque));

      cups_auth_param(schemedata, "qop", http->qop, sizeof(http->qop));

      cups_auth_param(schemedata, "realm", http->realm, sizeof(http->realm));

      if (_httpSetDigestAuthString(http, nonce, method, resource))

      {

  DEBUG_puts("2cupsDoAuthentication: Using Digest.");

        break;

      }

    }

  }

  if (http->authstring && http->authstring[0])

  {

    DEBUG_printf("1cupsDoAuthentication: authstring=\"%s\".", http->authstring);

    return (0);

  }

  else

  {

    DEBUG_puts("1cupsDoAuthentication: No supported schemes.");

    http->status = HTTP_STATUS_CUPS_AUTHORIZATION_CANCELED;

    return (-1);

  }

}

#ifdef HAVE_GSSAPI

//

// '_cupsSetNegotiateAuthString()' - Set the Kerberos authentication string.

//

int         // O - 0 on success, negative on error

_cupsSetNegotiateAuthString(

    http_t     *http,     // I - Connection to server

    const char *method,     // I - Request method ("GET", "POST", "PUT")

    const char *resource)   // I - Resource path

{

  OM_uint32 minor_status,   // Minor status code

    major_status;   // Major status code

  gss_buffer_desc output_token = GSS_C_EMPTY_BUFFER;

          // Output token

#  ifdef __APPLE__

  // If the weak-linked GSSAPI/Kerberos library is not present, don't try

  // to use it...

  if (&gss_init_sec_context == NULL)

  {

    DEBUG_puts("1_cupsSetNegotiateAuthString: Weak-linked GSSAPI/Kerberos "

               "framework is not present");

    return (CUPS_GSS_NONE);

  }

#  endif // __APPLE__

  if (!strcmp(http->hostname, "localhost") || http->hostname[0] == '/' || isdigit(http->hostname[0] & 255) || !strchr(http->hostname, '.'))

  {

    DEBUG_printf("1_cupsSetNegotiateAuthString: Kerberos not available for host \"%s\".", http->hostname);

    return (CUPS_GSS_NONE);

  }

  if (http->gssname == GSS_C_NO_NAME)

  {

    http->gssname = cups_gss_getname(http, _cupsGSSServiceName());

  }

  if (http->gssctx != GSS_C_NO_CONTEXT)

  {

    gss_delete_sec_context(&minor_status, &http->gssctx, GSS_C_NO_BUFFER);

    http->gssctx = GSS_C_NO_CONTEXT;

  }

  major_status = gss_init_sec_context(&minor_status, GSS_C_NO_CREDENTIAL,

              &http->gssctx,

              http->gssname, http->gssmech,

              GSS_C_MUTUAL_FLAG | GSS_C_INTEG_FLAG,

              GSS_C_INDEFINITE,

              GSS_C_NO_CHANNEL_BINDINGS,

              GSS_C_NO_BUFFER, &http->gssmech,

              &output_token, NULL, NULL);

#  ifdef HAVE_GSS_ACQUIRE_CRED_EX_F

  if (major_status == GSS_S_NO_CRED)

  {

    // Ask the user for credentials...

    char    prompt[1024], // Prompt for user

      userbuf[256]; // Kerberos username

    const char    *username,  // Username string

      *password;  // Password string

    _cups_gss_acquire_t data;   // Callback data

    gss_auth_identity_desc identity;  // Kerberos user identity

    _cups_globals_t *cg = _cupsGlobals();

          // Per-thread global data

    if (!cg->lang_default)

      cg->lang_default = cupsLangDefault();

    snprintf(prompt, sizeof(prompt),

             _cupsLangString(cg->lang_default, _("Password for %s on %s? ")),

       cupsGetUser(), http->gsshost);

    if ((password = cupsGetPassword2(prompt, http, method, resource)) == NULL)

      return (CUPS_GSS_FAIL);

    // Try to acquire credentials...

    username = cupsGetUser();

    if (!strchr(username, '@'))

    {

      snprintf(userbuf, sizeof(userbuf), "%s@%s", username, http->gsshost);

      username = userbuf;

    }

    identity.type           = GSS_AUTH_IDENTITY_TYPE_1;

    identity.flags          = 0;

    identity.username       = (char *)username;

    identity.realm          = (char *)"";

    identity.password       = (char *)password;

    identity.credentialsRef = NULL;

    data.sem   = dispatch_semaphore_create(0);

    data.major = 0;

    data.creds = NULL;

    if (data.sem)

    {

      major_status = gss_acquire_cred_ex_f(NULL, GSS_C_NO_NAME, 0, GSS_C_INDEFINITE, GSS_KRB5_MECHANISM, GSS_C_INITIATE, (gss_auth_identity_t)&identity, &data, cups_gss_acquire);

      if (major_status == GSS_S_COMPLETE)

      {

  dispatch_semaphore_wait(data.sem, DISPATCH_TIME_FOREVER);

  major_status = data.major;

      }

      dispatch_release(data.sem);

      if (major_status == GSS_S_COMPLETE)

      {

        OM_uint32 release_minor;  // Minor status from releasing creds

  major_status = gss_init_sec_context(&minor_status, data.creds,

              &http->gssctx,

              http->gssname, http->gssmech,

              GSS_C_MUTUAL_FLAG | GSS_C_INTEG_FLAG,

              GSS_C_INDEFINITE,

              GSS_C_NO_CHANNEL_BINDINGS,

              GSS_C_NO_BUFFER, &http->gssmech,

              &output_token, NULL, NULL);

        gss_release_cred(&release_minor, &data.creds);

      }

    }

  }

#  else

  (void)method;

  (void)resource;

#  endif // HAVE_GSS_ACQUIRED_CRED_EX_F

  if (major_status == GSS_S_NO_CRED)

  {

    cups_gss_printf(major_status, minor_status, "_cupsSetNegotiateAuthString: No credentials");

    return (CUPS_GSS_NONE);

  }

  else if (GSS_ERROR(major_status))

  {

    cups_gss_printf(major_status, minor_status, "_cupsSetNegotiateAuthString: Unable to initialize security context");

    return (CUPS_GSS_FAIL);

  }

#  ifdef DEBUG

  else if (major_status == GSS_S_CONTINUE_NEEDED)

    cups_gss_printf(major_status, minor_status, "_cupsSetNegotiateAuthString: Continuation needed");

#  endif // DEBUG

  if (output_token.length > 0 && output_token.length <= 65536)

  {

    // Allocate the authorization string since Windows KDCs can have

    // arbitrarily large credentials...

    size_t authsize = (size_t)(10 + // "Negotiate "

             ((output_token.length * 4 / 3 + 3) & ~3U) + 1);

            // Base64 + nul

    httpSetAuthString(http, NULL, NULL);

    if ((http->authstring = malloc((size_t)authsize)) == NULL)

    {

      http->authstring = http->_authstring;

      authsize         = sizeof(http->_authstring);

    }

    cupsCopyString(http->authstring, "Negotiate ", (size_t)authsize);

    httpEncode64_3(http->authstring + 10, authsize - 10, output_token.value, output_token.length, false);

    gss_release_buffer(&minor_status, &output_token);

  }

  else

  {

    DEBUG_printf("1_cupsSetNegotiateAuthString: Kerberos credentials too large - %d bytes!", (int)output_token.length);

    gss_release_buffer(&minor_status, &output_token);

    return (CUPS_GSS_FAIL);

  }

  return (CUPS_GSS_OK);

}

#endif // HAVE_GSSAPI

//

// 'cups_auth_find()' - Find the named WWW-Authenticate scheme.

//

// The "www_authenticate" argument points to the current position in the header.

//

// Returns `NULL` if the auth scheme is not present.

//

static const char *       // O - Start of matching scheme or `NULL` if not found

cups_auth_find(const char *www_authenticate,  // I - Pointer into WWW-Authenticate header

               const char *scheme)    // I - Authentication scheme

{

  size_t  schemelen = strlen(scheme); // Length of scheme

  DEBUG_printf("8cups_auth_find(www_authenticate=\"%s\", scheme=\"%s\"(%d))", www_authenticate, scheme, (int)schemelen);

  while (*www_authenticate)

  {

    // Skip leading whitespace and commas...

    DEBUG_printf("9cups_auth_find: Before whitespace: \"%s\"", www_authenticate);

    while (isspace(*www_authenticate & 255) || *www_authenticate == ',')

      www_authenticate ++;

    DEBUG_printf("9cups_auth_find: After whitespace: \"%s\"", www_authenticate);

    // See if this is "Scheme" followed by whitespace or the end of the string.

    if (!strncmp(www_authenticate, scheme, schemelen) && (isspace(www_authenticate[schemelen] & 255) || www_authenticate[schemelen] == ',' || !www_authenticate[schemelen]))

    {

      // Yes, this is the start of the scheme-specific information...

      DEBUG_printf("9cups_auth_find: Returning \"%s\".", www_authenticate);

      return (www_authenticate);

    }

    // Skip the scheme name or param="value" string...

    while (!isspace(*www_authenticate & 255) && *www_authenticate)

    {

      if (*www_authenticate == '\"')

      {

        // Skip quoted value...

        www_authenticate ++;

        while (*www_authenticate && *www_authenticate != '\"')

          www_authenticate ++;

        DEBUG_printf("9cups_auth_find: After quoted: \"%s\"", www_authenticate);

      }

      www_authenticate ++;

    }

    DEBUG_printf("9cups_auth_find: After skip: \"%s\"", www_authenticate);

  }

  DEBUG_puts("9cups_auth_find: Returning NULL.");

  return (NULL);

}

//

// 'cups_auth_param()' - Copy the value for the named authentication parameter,

//                       if present.

//

static const char *       // O - Parameter value or `NULL` if not present

cups_auth_param(const char *scheme,   // I - Pointer to auth data

                const char *name,   // I - Name of parameter

                char       *value,    // I - Value buffer

                size_t     valsize)   // I - Size of value buffer

{

  char    *valptr = value,    // Pointer into value buffer

          *valend = value + valsize - 1;  // Pointer to end of buffer

  size_t  namelen = strlen(name);   // Name length

  bool    param;        // Is this a parameter?

  DEBUG_printf("8cups_auth_param(scheme=\"%s\", name=\"%s\", value=%p, valsize=%d)", scheme, name, (void *)value, (int)valsize);

  while (!isspace(*scheme & 255) && *scheme)

    scheme ++;

  while (*scheme)

  {

    while (isspace(*scheme & 255) || *scheme == ',')

      scheme ++;

    if (!strncmp(scheme, name, namelen) && scheme[namelen] == '=')

    {

      // Found the parameter, copy the value...

      scheme += namelen + 1;

      if (*scheme == '\"')

      {

        scheme ++;

  while (*scheme && *scheme != '\"')

  {

    if (valptr < valend)

      *valptr++ = *scheme;

    scheme ++;

  }

      }

      else

      {

  while (*scheme && strchr("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-._~+/=", *scheme))

  {

    if (valptr < valend)

      *valptr++ = *scheme;

    scheme ++;

  }

      }

      *valptr = '\0';

      DEBUG_printf("9cups_auth_param: Returning \"%s\".", value);

      return (value);

    }

    // Skip the param=value string...

    param = false;

    while (!isspace(*scheme & 255) && *scheme)

    {

      if (*scheme == '=')

      {

        param = true;

      }

      else if (*scheme == '\"')

      {

        // Skip quoted value...

        scheme ++;

        while (*scheme && *scheme != '\"')

          scheme ++;

      }

      scheme ++;

    }

    // If this wasn't a parameter, we are at the end of this scheme's

    // parameters...

    if (!param)

      break;

  }

  *value = '\0';

  DEBUG_puts("9cups_auth_param: Returning NULL.");

  return (NULL);

}

//

// 'cups_auth_scheme()' - Get the (next) WWW-Authenticate scheme.

//

// The "www_authenticate" argument points to the current position in the header.

//

// Returns `NULL` if there are no (more) auth schemes present.

//

static const char *       // O - Start of scheme or `NULL` if not found

cups_auth_scheme(const char *www_authenticate,  // I - Pointer into WWW-Authenticate header

     char       *scheme,    // I - Scheme name buffer

     size_t     schemesize)   // I - Size of buffer

{

  const char  *start;       // Start of scheme data

  char    *sptr = scheme,     // Pointer into scheme buffer

    *send = scheme + schemesize - 1;// End of scheme buffer

  bool    param;        // Is this a parameter?

  DEBUG_printf("8cups_auth_scheme(www_authenticate=\"%s\", scheme=%p, schemesize=%u)", www_authenticate, (void *)scheme, (unsigned)schemesize);

  while (*www_authenticate)

  {

    // Skip leading whitespace and commas...

    while (isspace(*www_authenticate & 255) || *www_authenticate == ',')

      www_authenticate ++;

    // Parse the scheme name or param="value" string...

    for (sptr = scheme, start = www_authenticate, param = false; *www_authenticate && *www_authenticate != ',' && !isspace(*www_authenticate & 255); www_authenticate ++)

    {

      if (*www_authenticate == '=')

      {

        param = true;

      }

      else if (!param && sptr < send)

      {

        *sptr++ = *www_authenticate;

      }

      else if (*www_authenticate == '\"')

      {

        // Skip quoted value...

        do

        {

          www_authenticate ++;

        }

        while (*www_authenticate && *www_authenticate != '\"');

      }

    }

    if (sptr > scheme && !param)

    {

      *sptr = '\0';

      DEBUG_printf("9cups_auth_scheme: Returning \"%s\".", start);

      return (start);

    }

  }

  *scheme = '\0';

  DEBUG_puts("9cups_auth_scheme: Returning NULL.");

  return (NULL);

}

//

// 'cups_do_local_auth()' - Use local credentials if available/applicable.

//

static bool       // O - `true` if authorized, `false` otherwise

cups_do_local_auth(http_t *http)  // I - HTTP connection to server

{

#if !_WIN32 && !__EMX__

  int     pid;    // Current process ID

  FILE      *fp;    // Certificate file

  char      trc[16],  // Try Root Certificate parameter

      filename[1024]; // Certificate filename

  const char    *www_auth,  // WWW-Authenticate header

      *schemedata;  // Data for the named auth scheme

  _cups_globals_t *cg = _cupsGlobals(); // Global data

#  if defined(HAVE_AUTHORIZATION_H)

  OSStatus    status;   // Status

  AuthorizationItem auth_right; // Authorization right

  AuthorizationRights auth_rights;  // Authorization rights

  AuthorizationFlags  auth_flags; // Authorization flags

  AuthorizationExternalForm auth_extrn; // Authorization ref external

  char      auth_key[1024]; // Buffer

  char      buffer[1024]; // Buffer

#  endif // HAVE_AUTHORIZATION_H

  DEBUG_printf("7cups_local_auth(http=%p) hostaddr=%s, hostname=\"%s\"", (void *)http, httpAddrString(http->hostaddr, filename, sizeof(filename)), http->hostname);

  // See if we are accessing localhost...

  if (!httpAddrIsLocalhost(httpGetAddress(http)))

  {

    DEBUG_puts("8cups_local_auth: Not a local connection, returning false.");

    return (false);

  }

  www_auth = httpGetField(http, HTTP_FIELD_WWW_AUTHENTICATE);

#  if defined(HAVE_AUTHORIZATION_H)

  // Delete any previous authorization reference...

  if (http->auth_ref)

  {

    AuthorizationFree(http->auth_ref, kAuthorizationFlagDefaults);

    http->auth_ref = NULL;

  }

  if (!getenv("GATEWAY_INTERFACE") && (schemedata = cups_auth_find(www_auth, "AuthRef")) != NULL && cups_auth_param(schemedata, "key", auth_key, sizeof(auth_key)))

  {

    status = AuthorizationCreate(NULL, kAuthorizationEmptyEnvironment, kAuthorizationFlagDefaults, &http->auth_ref);

    if (status != errAuthorizationSuccess)

    {

      DEBUG_printf("8cups_local_auth: AuthorizationCreate() returned %d, returning false.", (int)status);

      return (false);

    }

    auth_right.name        = auth_key;

    auth_right.valueLength = 0;

    auth_right.value       = NULL;

    auth_right.flags       = 0;

    auth_rights.count = 1;

    auth_rights.items = &auth_right;

    auth_flags = kAuthorizationFlagDefaults |

     kAuthorizationFlagPreAuthorize |

     kAuthorizationFlagInteractionAllowed |

     kAuthorizationFlagExtendRights;

    status = AuthorizationCopyRights(http->auth_ref, &auth_rights,

             kAuthorizationEmptyEnvironment,

             auth_flags, NULL);

    if (status == errAuthorizationSuccess)

      status = AuthorizationMakeExternalForm(http->auth_ref, &auth_extrn);

    if (status == errAuthorizationSuccess)

    {

      // Set the authorization string and return...

      httpEncode64_3(buffer, sizeof(buffer), (void *)&auth_extrn, sizeof(auth_extrn), false);

      httpSetAuthString(http, "AuthRef", buffer);

      DEBUG_printf("8cups_local_auth: Returning authstring=\"%s\", returning true.", http->authstring);

      return (true);

    }

    else if (status == errAuthorizationCanceled)

    {

      return (false);

    }

    DEBUG_printf("9cups_local_auth: AuthorizationCopyRights() returned %d.", (int)status);

   // Fall through to try certificates...

  }

#  endif // HAVE_AUTHORIZATION_H

#  if defined(SO_PEERCRED) && defined(AF_LOCAL)

  // See if we can authenticate using the peer credentials provided over a

  // domain socket; if so, specify "PeerCred username" as the authentication

  // information...

  if (http->hostaddr->addr.sa_family == AF_LOCAL &&

      !getenv("GATEWAY_INTERFACE") && // Not via CGI programs...

      cups_auth_find(www_auth, "PeerCred"))

  {

    // Verify that the current cupsGetUser() matches the current UID...

    struct passwd pwd;    // Password information

    struct passwd *result;  // Auxiliary pointer

    const char    *username;  // Current username

    username = cupsGetUser();

    getpwnam_r(username, &pwd, cg->pw_buf, PW_BUF_SIZE, &result);

    if (result && pwd.pw_uid == getuid())

    {

      httpSetAuthString(http, "PeerCred", username);

      DEBUG_printf("8cups_local_auth: Returning authstring=\"%s\", returning true.", http->authstring);

      return (true);

    }

  }

#  endif // SO_PEERCRED && AF_LOCAL

  if ((schemedata = cups_auth_find(www_auth, "Local")) == NULL)

    return (false);

  // Try opening a certificate file for this PID.  If that fails,

  // try the root certificate...

  pid = getpid();

  snprintf(filename, sizeof(filename), "%s/certs/%d", cg->cups_statedir, pid);

  if ((fp = fopen(filename, "r")) == NULL && pid > 0)

  {

    // No certificate for this PID; see if we can get the root certificate...

    DEBUG_printf("9cups_local_auth: Unable to open file \"%s\": %s", filename, strerror(errno));

    if (!cups_auth_param(schemedata, "trc", trc, sizeof(trc)))

    {

      // Scheduler doesn't want us to use the root certificate...

      return (false);

    }

    snprintf(filename, sizeof(filename), "%s/certs/0", cg->cups_statedir);

    if ((fp = fopen(filename, "r")) == NULL)

      DEBUG_printf("9cups_local_auth: Unable to open file \"%s\": %s", filename, strerror(errno));

  }

  if (fp)

  {

    // Read the certificate from the file...

    char  certificate[33],  // Certificate string

    *certptr;   // Pointer to certificate string

    certptr = fgets(certificate, sizeof(certificate), fp);

    fclose(fp);

    if (certptr)

    {

      // Set the authorization string and return...

      httpSetAuthString(http, "Local", certificate);

      DEBUG_printf("8cups_local_auth: Returning authstring=\"%s\", returning true.", http->authstring);

      return (true);

    }

  }

#endif // !_WIN32 && !__EMX__

  DEBUG_puts("8cups_do_local_auth: Returning false.");

  return (false);

}

#ifdef HAVE_GSSAPI

#  ifdef HAVE_GSS_ACQUIRE_CRED_EX_F

//

// 'cups_gss_acquire()' - Kerberos credentials callback.

//

static void

cups_gss_acquire(

    void            *ctx,   // I - Caller context

    OM_uint32       major,    // I - Major error code

    gss_status_id_t status,   // I - Status (unused)

    gss_cred_id_t   creds,    // I - Credentials (if any)

    gss_OID_set     oids,   // I - Mechanism OIDs (unused)

    OM_uint32       time_rec)   // I - Timestamp (unused)

{

  uint32_t    min;    // Minor error code

  _cups_gss_acquire_t *data;    // Callback data

  (void)status;

  (void)time_rec;

  data        = (_cups_gss_acquire_t *)ctx;

  data->major = major;

  data->creds = creds;

  gss_release_oid_set(&min, &oids);

  dispatch_semaphore_signal(data->sem);

}

#  endif // HAVE_GSS_ACQUIRE_CRED_EX_F

//

// 'cups_gss_getname()' - Get CUPS service credentials for authentication.

//

static gss_name_t     // O - Server name

cups_gss_getname(

    http_t     *http,     // I - Connection to server

    const char *service_name)   // I - Service name

{

  gss_buffer_desc token = GSS_C_EMPTY_BUFFER;

          // Service token

  OM_uint32   major_status,   // Major status code

      minor_status;   // Minor status code

  gss_name_t    server_name;    // Server name

  char      buf[1024];    // Name buffer

  DEBUG_printf("7cups_gss_getname(http=%p, service_name=\"%s\")", (void *)http, service_name);

  // Get the hostname...

  if (!http->gsshost[0])

  {

    httpGetHostname(http, http->gsshost, sizeof(http->gsshost));

    if (!strcmp(http->gsshost, "localhost"))

    {

      if (gethostname(http->gsshost, sizeof(http->gsshost)) < 0)

      {

  DEBUG_printf("1cups_gss_getname: gethostname() failed: %s", strerror(errno));

  http->gsshost[0] = '\0';

  return (NULL);

      }

      if (!strchr(http->gsshost, '.'))

      {

        // The hostname is not a FQDN, so look it up...

  struct hostent  *host;    // Host entry to get FQDN

  if ((host = gethostbyname(http->gsshost)) != NULL && host->h_name)

  {

    // Use the resolved hostname...

    cupsCopyString(http->gsshost, host->h_name, sizeof(http->gsshost));

  }

  else

  {

    DEBUG_printf("1cups_gss_getname: gethostbyname(\"%s\") failed.", http->gsshost);

    http->gsshost[0] = '\0';

    return (NULL);

  }

      }

    }

  }

  // Get a service name we can use for authentication purposes...

  snprintf(buf, sizeof(buf), "%s@%s", service_name, http->gsshost);

  DEBUG_printf("8cups_gss_getname: Looking up \"%s\".", buf);

  token.value  = buf;

  token.length = strlen(buf);

  server_name  = GSS_C_NO_NAME;

  major_status = gss_import_name(&minor_status, &token,

         GSS_C_NT_HOSTBASED_SERVICE,

         &server_name);

  if (GSS_ERROR(major_status))

  {

    cups_gss_printf(major_status, minor_status,

                    "cups_gss_getname: gss_import_name() failed");

    return (NULL);

  }

  return (server_name);

}

#  ifdef DEBUG

//

// 'cups_gss_printf()' - Show debug error messages from GSSAPI.

//

static void

cups_gss_printf(OM_uint32  major_status,// I - Major status code

    OM_uint32  minor_status,// I - Minor status code

    const char *message)  // I - Prefix for error message

{

  OM_uint32 err_major_status, // Major status code for display