documented fix

[gnutls.git] / lib / gnutls_x509.c

/*
 * Copyright (C) 2002-2012 Free Software Foundation, Inc.
 *
 * Author: Nikos Mavrogiannopoulos
 *
 * This file is part of GnuTLS.
 *
 * The GnuTLS is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation; either version 3 of
 * the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>
 *
 */

#include <gnutls_int.h>
#include "gnutls_auth.h"
#include "gnutls_errors.h"
#include <auth/cert.h>
#include "gnutls_dh.h"
#include "gnutls_num.h"
#include "gnutls_datum.h"
#include <gnutls_pk.h>
#include <algorithms.h>
#include <gnutls_global.h>
#include <gnutls_record.h>
#include <gnutls_sig.h>
#include <gnutls_state.h>
#include <gnutls_pk.h>
#include <gnutls_str.h>
#include <debug.h>
#include <x509_b64.h>
#include <gnutls_x509.h>
#include "x509/common.h"
#include "x509/x509_int.h"
#include <gnutls_str_array.h>
#include "read-file.h"
#ifdef _WIN32
# include <wincrypt.h>
#endif

/*
 * some x509 certificate parsing functions.
 */

/* Check if the number of bits of the key in the certificate
 * is unacceptable.
  */
inline static int
check_bits (gnutls_session_t session, gnutls_x509_crt_t crt, unsigned int max_bits)
{
  int ret, pk;
  unsigned int bits;

  ret = gnutls_x509_crt_get_pk_algorithm (crt, &bits);
  if (ret < 0)
    {
      gnutls_assert ();
      return ret;
    }
  pk = ret;

  if (bits > max_bits && max_bits > 0)
    {
      gnutls_assert ();
      return GNUTLS_E_CONSTRAINT_ERROR;
    }

  if (gnutls_pk_bits_to_sec_param(pk, bits) == GNUTLS_SEC_PARAM_INSECURE)
    {
      gnutls_assert();
      _gnutls_audit_log(session, "The security level of the certificate (%s: %u) is weak\n", gnutls_pk_get_name(pk), bits);
      if (session->internals.priorities.allow_weak_keys == 0)
        return gnutls_assert_val(GNUTLS_E_CERTIFICATE_ERROR);
    }

  return 0;
}


#define CLEAR_CERTS for(x=0;x<peer_certificate_list_size;x++) { \
        if (peer_certificate_list[x]) \
                gnutls_x509_crt_deinit(peer_certificate_list[x]); \
        } \
        gnutls_free( peer_certificate_list)

/*-
 * _gnutls_x509_cert_verify_peers - return the peer's certificate status
 * @session: is a gnutls session
 *
 * This function will try to verify the peer's certificate and return its status (TRUSTED, REVOKED etc.).
 * The return value (status) should be one of the gnutls_certificate_status_t enumerated elements.
 * However you must also check the peer's name in order to check if the verified certificate belongs to the
 * actual peer. Returns a negative error code in case of an error, or GNUTLS_E_NO_CERTIFICATE_FOUND if no certificate was sent.
 -*/
int
_gnutls_x509_cert_verify_peers (gnutls_session_t session,
                                unsigned int *status)
{
  cert_auth_info_t info;
  gnutls_certificate_credentials_t cred;
  gnutls_x509_crt_t *peer_certificate_list;
  int peer_certificate_list_size, i, x, ret;

  CHECK_AUTH (GNUTLS_CRD_CERTIFICATE, GNUTLS_E_INVALID_REQUEST);

  info = _gnutls_get_auth_info (session);
  if (info == NULL)
    {
      gnutls_assert ();
      return GNUTLS_E_INVALID_REQUEST;
    }

  cred = (gnutls_certificate_credentials_t)
    _gnutls_get_cred (session->key, GNUTLS_CRD_CERTIFICATE, NULL);
  if (cred == NULL)
    {
      gnutls_assert ();
      return GNUTLS_E_INSUFFICIENT_CREDENTIALS;
    }

  if (info->raw_certificate_list == NULL || info->ncerts == 0)
    return GNUTLS_E_NO_CERTIFICATE_FOUND;

  if (info->ncerts > cred->verify_depth && cred->verify_depth > 0)
    {
      gnutls_assert ();
      return GNUTLS_E_CONSTRAINT_ERROR;
    }

  /* generate a list of gnutls_certs based on the auth info
   * raw certs.
   */
  peer_certificate_list_size = info->ncerts;
  peer_certificate_list =
    gnutls_calloc (peer_certificate_list_size, sizeof (gnutls_x509_crt_t));
  if (peer_certificate_list == NULL)
    {
      gnutls_assert ();
      return GNUTLS_E_MEMORY_ERROR;
    }

  for (i = 0; i < peer_certificate_list_size; i++)
    {
      ret = gnutls_x509_crt_init (&peer_certificate_list[i]);
      if (ret < 0)
        {
          gnutls_assert ();
          CLEAR_CERTS;
          return ret;
        }

      ret =
        gnutls_x509_crt_import (peer_certificate_list[i],
                                &info->raw_certificate_list[i],
                                GNUTLS_X509_FMT_DER);
      if (ret < 0)
        {
          gnutls_assert ();
          CLEAR_CERTS;
          return ret;
        }

      ret = check_bits (session, peer_certificate_list[i], cred->verify_bits);
      if (ret < 0)
        {
          gnutls_assert ();
          CLEAR_CERTS;
          return ret;
        }

    }

  /* Verify certificate 
   */

  ret = gnutls_x509_trust_list_verify_crt (cred->tlist, peer_certificate_list,
                                     peer_certificate_list_size,
                                     cred->verify_flags | session->internals.
                                     priorities.additional_verify_flags,
                                     status, NULL);

  CLEAR_CERTS;

  if (ret < 0)
    {
      gnutls_assert ();
      return ret;
    }

  return 0;
}

/*
 * Read certificates and private keys, from files, memory etc.
 */


/* Returns the name of the certificate of a null name
 */
static int get_x509_name(gnutls_x509_crt_t crt, gnutls_str_array_t *names)
{
size_t max_size;
int i, ret = 0, ret2;
char name[MAX_CN];

  for (i = 0; !(ret < 0); i++)
    {
      max_size = sizeof(name);

      ret = gnutls_x509_crt_get_subject_alt_name(crt, i, name, &max_size, NULL);
      if (ret == GNUTLS_SAN_DNSNAME)
        {
          ret2 = _gnutls_str_array_append(names, name, max_size);
          if (ret2 < 0)
            {
              _gnutls_str_array_clear(names);
              return gnutls_assert_val(ret2);
            }
        }
    }
    
  max_size = sizeof(name);
  ret = gnutls_x509_crt_get_dn_by_oid (crt, OID_X520_COMMON_NAME, 0, 0, name, &max_size);
  if (ret >= 0)
    {
      ret = _gnutls_str_array_append(names, name, max_size);
      if (ret < 0)
        {
          _gnutls_str_array_clear(names);
          return gnutls_assert_val(ret);
        }
    }
  
  return 0;
}

static int get_x509_name_raw(gnutls_datum_t *raw, gnutls_x509_crt_fmt_t type, gnutls_str_array_t *names)
{
int ret;
gnutls_x509_crt_t crt;

  ret = gnutls_x509_crt_init (&crt);
  if (ret < 0)
    {
      gnutls_assert ();
      return ret;
    }

  ret = gnutls_x509_crt_import (crt, raw, type);
  if (ret < 0)
    {
      gnutls_assert ();
      gnutls_x509_crt_deinit (crt);
      return ret;
    }

  ret = get_x509_name(crt, names);
  gnutls_x509_crt_deinit (crt);
  return ret;
}

/* Reads a DER encoded certificate list from memory and stores it to a
 * gnutls_cert structure. Returns the number of certificates parsed.
 */
static int
parse_der_cert_mem (gnutls_certificate_credentials_t res,
                    const void *input_cert, int input_cert_size)
{
  gnutls_datum_t tmp;
  gnutls_x509_crt_t crt;
  gnutls_pcert_st *ccert;
  int ret;
  gnutls_str_array_t names;
  
  _gnutls_str_array_init(&names);

  ccert = gnutls_malloc (sizeof (*ccert));
  if (ccert == NULL)
    {
      gnutls_assert ();
      return GNUTLS_E_MEMORY_ERROR;
    }

  ret = gnutls_x509_crt_init (&crt);
  if (ret < 0)
    {
      gnutls_assert ();
      goto cleanup;
    }

  tmp.data = (uint8_t *) input_cert;
  tmp.size = input_cert_size;

  ret = gnutls_x509_crt_import (crt, &tmp, GNUTLS_X509_FMT_DER);
  if (ret < 0)
    {
      gnutls_assert ();
      gnutls_x509_crt_deinit (crt);
      goto cleanup;
    }

  ret = get_x509_name(crt, &names);
  if (ret < 0)
    {
      gnutls_assert();
      gnutls_x509_crt_deinit (crt);
      goto cleanup;
    }

  ret = gnutls_pcert_import_x509 (ccert, crt, 0);
  gnutls_x509_crt_deinit (crt);

  if (ret < 0)
    {
      gnutls_assert ();
      goto cleanup;
    }

  ret = certificate_credential_append_crt_list (res, names, ccert, 1);
  if (ret < 0)
    {
      gnutls_assert ();
      goto cleanup;
    }

  return ret;

cleanup:
  _gnutls_str_array_clear(&names);
  gnutls_free (ccert);
  return ret;
}

/* Reads a base64 encoded certificate list from memory and stores it to
 * a gnutls_cert structure. Returns the number of certificate parsed.
 */
static int
parse_pem_cert_mem (gnutls_certificate_credentials_t res,
                    const char *input_cert, int input_cert_size)
{
  int size;
  const char *ptr;
  gnutls_datum_t tmp;
  int ret, count, i;
  gnutls_pcert_st *certs = NULL;
  gnutls_str_array_t names;

  _gnutls_str_array_init(&names);

  /* move to the certificate
   */
  ptr = memmem (input_cert, input_cert_size,
                PEM_CERT_SEP, sizeof (PEM_CERT_SEP) - 1);
  if (ptr == NULL)
    ptr = memmem (input_cert, input_cert_size,
                  PEM_CERT_SEP2, sizeof (PEM_CERT_SEP2) - 1);

  if (ptr == NULL)
    {
      gnutls_assert ();
      return GNUTLS_E_BASE64_DECODING_ERROR;
    }
  size = input_cert_size - (ptr - input_cert);

  count = 0;

  do
    {
      certs = gnutls_realloc_fast (certs, (count + 1) * sizeof (gnutls_pcert_st));

      if (certs == NULL)
        {
          gnutls_assert ();
          ret = GNUTLS_E_MEMORY_ERROR;
          goto cleanup;
        }

      tmp.data = (void*)ptr;
      tmp.size = size;

      if (count == 0)
        {
          ret = get_x509_name_raw(&tmp, GNUTLS_X509_FMT_PEM, &names);
          if (ret < 0)
            {
              gnutls_assert();
              goto cleanup;
            }
        }

      ret = gnutls_pcert_import_x509_raw (&certs[count], &tmp, GNUTLS_X509_FMT_PEM, 0);
      if (ret < 0)
        {
          gnutls_assert ();
          goto cleanup;
        }

      /* now we move ptr after the pem header 
       */
      ptr++;
      /* find the next certificate (if any)
       */
      size = input_cert_size - (ptr - input_cert);

      if (size > 0)
        {
          char *ptr3;

          ptr3 = memmem (ptr, size, PEM_CERT_SEP, sizeof (PEM_CERT_SEP) - 1);
          if (ptr3 == NULL)
            ptr3 = memmem (ptr, size, PEM_CERT_SEP2,
                           sizeof (PEM_CERT_SEP2) - 1);

          ptr = ptr3;
        }
      else
        ptr = NULL;

      count++;

    }
  while (ptr != NULL);

  ret = certificate_credential_append_crt_list (res, names, certs, count);
  if (ret < 0)
    {
      gnutls_assert ();
      goto cleanup;
    }

  return count;

cleanup:
  _gnutls_str_array_clear(&names);
  for (i=0;i<count;i++)
    gnutls_pcert_deinit(&certs[i]);
  gnutls_free(certs);
  return ret;
}



/* Reads a DER or PEM certificate from memory
 */
static int
read_cert_mem (gnutls_certificate_credentials_t res, const void *cert,
               int cert_size, gnutls_x509_crt_fmt_t type)
{
  int ret;

  if (type == GNUTLS_X509_FMT_DER)
    ret = parse_der_cert_mem (res, cert, cert_size);
  else
    ret = parse_pem_cert_mem (res, cert, cert_size);

  if (ret < 0)
    {
      gnutls_assert ();
      return ret;
    }

  return ret;
}

/* Reads a PEM encoded PKCS-1 RSA/DSA private key from memory.  Type
 * indicates the certificate format.  KEY can be NULL, to indicate
 * that GnuTLS doesn't know the private key.
 */
static int
read_key_mem (gnutls_certificate_credentials_t res,
              const void *key, int key_size, gnutls_x509_crt_fmt_t type)
{
  int ret;
  gnutls_datum_t tmp;
  gnutls_privkey_t privkey;

  if (key)
    {
      tmp.data = (uint8_t *) key;
      tmp.size = key_size;

      ret = gnutls_privkey_init(&privkey);
      if (ret < 0)
        {
          gnutls_assert ();
          return ret;
        }
      
      if (res->pin.cb)
        gnutls_privkey_set_pin_function(privkey, res->pin.cb, res->pin.data);

      ret = gnutls_privkey_import_x509_raw (privkey, &tmp, type, NULL, 0);
      if (ret < 0)
        {
          gnutls_assert ();
          return ret;
        }

      ret = certificate_credentials_append_pkey (res, privkey);
      if (ret < 0)
        {
          gnutls_assert ();
          gnutls_privkey_deinit (privkey);
          return ret;
        }

    }
  else
    {
      gnutls_assert ();
      return GNUTLS_E_INVALID_REQUEST;
    }


  return 0;
}


/* Reads a private key from a token.
 */
static int
read_key_url (gnutls_certificate_credentials_t res, const char *url)
{
  int ret;
  gnutls_privkey_t pkey = NULL;

  /* allocate space for the pkey list
   */
  ret = gnutls_privkey_init (&pkey);
  if (ret < 0)
    {
      gnutls_assert ();
      return ret;
    }

  if (res->pin.cb)
    gnutls_privkey_set_pin_function(pkey, res->pin.cb, res->pin.data);

  ret = gnutls_privkey_import_url (pkey, url, 0);
  if (ret < 0)
    {
      gnutls_assert ();
      goto cleanup;
    }

  ret = certificate_credentials_append_pkey (res, pkey);
  if (ret < 0)
    {
      gnutls_assert ();
      goto cleanup;
    }

  return 0;

cleanup:
  if (pkey)
    gnutls_privkey_deinit (pkey);

  return ret;
}

#ifdef ENABLE_PKCS11
/* Reads a private key from a token.
 */
static int
read_cas_url (gnutls_certificate_credentials_t res, const char *url)
{
  int ret;
  gnutls_x509_crt_t *xcrt_list = NULL;
  gnutls_pkcs11_obj_t *pcrt_list = NULL;
  unsigned int pcrt_list_size = 0;

  /* FIXME: should we use login? */
  ret =
    gnutls_pkcs11_obj_list_import_url (NULL, &pcrt_list_size, url,
                                       GNUTLS_PKCS11_OBJ_ATTR_CRT_TRUSTED, 0);
  if (ret < 0 && ret != GNUTLS_E_SHORT_MEMORY_BUFFER)
    {
      gnutls_assert ();
      return ret;
    }

  if (pcrt_list_size == 0)
    {
      gnutls_assert ();
      return 0;
    }

  pcrt_list = gnutls_malloc (sizeof (*pcrt_list) * pcrt_list_size);
  if (pcrt_list == NULL)
    {
      gnutls_assert ();
      return GNUTLS_E_MEMORY_ERROR;
    }

  ret =
    gnutls_pkcs11_obj_list_import_url (pcrt_list, &pcrt_list_size, url,
                                       GNUTLS_PKCS11_OBJ_ATTR_CRT_TRUSTED, 0);
  if (ret < 0)
    {
      gnutls_assert ();
      goto cleanup;
    }

  xcrt_list = gnutls_malloc (sizeof (*xcrt_list) * pcrt_list_size);
  if (xcrt_list == NULL)
    {
      gnutls_assert ();
      ret = GNUTLS_E_MEMORY_ERROR;
      goto cleanup;
    }

  ret =
    gnutls_x509_crt_list_import_pkcs11 (xcrt_list, pcrt_list_size, pcrt_list,
                                        0);
  if (ret < 0)
    {
      gnutls_assert ();
      goto cleanup;
    }

  ret = gnutls_x509_trust_list_add_cas(res->tlist, xcrt_list, pcrt_list_size, 0);
  if (ret < 0)
    {
      gnutls_assert();
      goto cleanup;
    }

cleanup:
  gnutls_free (xcrt_list);
  gnutls_free (pcrt_list);

  return ret;

}


/* Reads a certificate key from a token.
 */
static int
read_cert_url (gnutls_certificate_credentials_t res, const char *url)
{
  int ret;
  gnutls_x509_crt_t crt;
  gnutls_pcert_st *ccert;
  gnutls_str_array_t names;
  
  _gnutls_str_array_init(&names);

  ccert = gnutls_malloc (sizeof (*ccert));
  if (ccert == NULL)
    {
      gnutls_assert ();
      return GNUTLS_E_MEMORY_ERROR;
    }

  ret = gnutls_x509_crt_init (&crt);
  if (ret < 0)
    {
      gnutls_assert ();
      goto cleanup;
    }

  if (res->pin.cb)
    gnutls_x509_crt_set_pin_function(crt, res->pin.cb, res->pin.data);

  ret = gnutls_x509_crt_import_pkcs11_url (crt, url, 0);
  if (ret == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE)
    ret =
      gnutls_x509_crt_import_pkcs11_url (crt, url,
                                         GNUTLS_PKCS11_OBJ_FLAG_LOGIN);

  if (ret < 0)
    {
      gnutls_assert ();
      gnutls_x509_crt_deinit (crt);
      goto cleanup;
    }

  ret = get_x509_name(crt, &names);
  if (ret < 0)
    {
      gnutls_assert ();
      gnutls_x509_crt_deinit (crt);
      goto cleanup;
    }

  ret = gnutls_pcert_import_x509 (ccert, crt, 0);
  gnutls_x509_crt_deinit (crt);

  if (ret < 0)
    {
      gnutls_assert ();
      goto cleanup;
    }

  ret = certificate_credential_append_crt_list (res, names, ccert, 1);
  if (ret < 0)
    {
      gnutls_assert ();
      goto cleanup;
    }

  return 0;

cleanup:
  _gnutls_str_array_clear(&names);
  gnutls_free (ccert);
  return ret;
}
#endif

/* Reads a certificate file
 */
static int
read_cert_file (gnutls_certificate_credentials_t res,
                const char *certfile, gnutls_x509_crt_fmt_t type)
{
  int ret;
  size_t size;
  char *data;

#ifdef ENABLE_PKCS11
  if (strncmp (certfile, "pkcs11:", 7) == 0)
    {
      return read_cert_url (res, certfile);
    }
#endif /* ENABLE_PKCS11 */

  data = read_binary_file (certfile, &size);

  if (data == NULL)
    {
      gnutls_assert ();
      return GNUTLS_E_FILE_ERROR;
    }

  ret = read_cert_mem (res, data, size, type);
  free (data);

  return ret;

}



/* Reads PKCS-1 RSA private key file or a DSA file (in the format openssl
 * stores it).
 */
static int
read_key_file (gnutls_certificate_credentials_t res,
               const char *keyfile, gnutls_x509_crt_fmt_t type)
{
  int ret;
  size_t size;
  char *data;

  if (gnutls_url_is_supported(keyfile))
    {
      return read_key_url (res, keyfile);
    }

  data = read_binary_file (keyfile, &size);

  if (data == NULL)
    {
      gnutls_assert ();
      return GNUTLS_E_FILE_ERROR;
    }

  ret = read_key_mem (res, data, size, type);
  free (data);

  return ret;
}

/**
 * gnutls_certificate_set_x509_key_mem:
 * @res: is a #gnutls_certificate_credentials_t structure.
 * @cert: contains a certificate list (path) for the specified private key
 * @key: is the private key, or %NULL
 * @type: is PEM or DER
 *
 * This function sets a certificate/private key pair in the
 * gnutls_certificate_credentials_t structure. This function may be called
 * more than once, in case multiple keys/certificates exist for the
 * server.
 *
 * Note that the keyUsage (2.5.29.15) PKIX extension in X.509 certificates
 * is supported. This means that certificates intended for signing cannot
 * be used for ciphersuites that require encryption.
 *
 * If the certificate and the private key are given in PEM encoding
 * then the strings that hold their values must be null terminated.
 *
 * The @key may be %NULL if you are using a sign callback, see
 * gnutls_sign_callback_set().
 *
 * Returns: %GNUTLS_E_SUCCESS (0) on success, or a negative error code.
 **/
int
gnutls_certificate_set_x509_key_mem (gnutls_certificate_credentials_t res,
                                     const gnutls_datum_t * cert,
                                     const gnutls_datum_t * key,
                                     gnutls_x509_crt_fmt_t type)
{
  int ret;

  /* this should be first
   */
  if ((ret = read_key_mem (res, key ? key->data : NULL,
                           key ? key->size : 0, type)) < 0)
    return ret;

  if ((ret = read_cert_mem (res, cert->data, cert->size, type)) < 0)
    return ret;

  res->ncerts++;

  if (key && (ret = _gnutls_check_key_cert_match (res)) < 0)
    {
      gnutls_assert ();
      return ret;
    }

  return 0;
}

static int check_if_sorted(gnutls_pcert_st * crt, int nr)
{
gnutls_x509_crt_t x509;
char prev_dn[MAX_DN];
char dn[MAX_DN];
size_t prev_dn_size, dn_size;
int i, ret;

  /* check if the X.509 list is ordered */
  if (nr > 1 && crt[0].type == GNUTLS_CRT_X509)
    {

      for (i=0;i<nr;i++)
        {
          ret = gnutls_x509_crt_init(&x509);
          if (ret < 0)
            return gnutls_assert_val(ret);
          
          ret = gnutls_x509_crt_import(x509, &crt[i].cert, GNUTLS_X509_FMT_DER);
          if (ret < 0)
            {
              ret = gnutls_assert_val(ret);
              goto cleanup;
            }
          
          if (i>0)
            {
              dn_size = sizeof(dn);
              ret = gnutls_x509_crt_get_dn(x509, dn, &dn_size);
              if (ret < 0)
                {
                  ret = gnutls_assert_val(ret);
                  goto cleanup;
                }
              
              if (dn_size != prev_dn_size || memcmp(dn, prev_dn, dn_size) != 0)
                {
                  ret = gnutls_assert_val(GNUTLS_E_CERTIFICATE_LIST_UNSORTED);
                  goto cleanup;
                }
            }

          prev_dn_size = sizeof(prev_dn);
          ret = gnutls_x509_crt_get_issuer_dn(x509, prev_dn, &prev_dn_size);
          if (ret < 0)
            {
              ret = gnutls_assert_val(ret);
              goto cleanup;
            }

          gnutls_x509_crt_deinit(x509);
        }
    }

  return 0;

cleanup:
  gnutls_x509_crt_deinit(x509);
  return ret;
}

int
certificate_credential_append_crt_list (gnutls_certificate_credentials_t res,
                                        gnutls_str_array_t names, gnutls_pcert_st * crt, int nr)
{
int ret;

  ret = check_if_sorted(crt, nr);
  if (ret < 0)
    return gnutls_assert_val(ret);

  res->certs = gnutls_realloc_fast (res->certs,
                                        (1 + res->ncerts) *
                                        sizeof (certs_st));
  if (res->certs == NULL)
    {
      gnutls_assert ();
      return GNUTLS_E_MEMORY_ERROR;
    }

  res->certs[res->ncerts].cert_list = crt;
  res->certs[res->ncerts].cert_list_length = nr;
  res->certs[res->ncerts].names = names;

  return 0;

}

int
certificate_credentials_append_pkey (gnutls_certificate_credentials_t res,
                                     gnutls_privkey_t pkey)
{
  res->pkey = gnutls_realloc_fast (res->pkey,
                                   (1 + res->ncerts) *
                                   sizeof (gnutls_privkey_t));
  if (res->pkey == NULL)
    {
      gnutls_assert ();
      return GNUTLS_E_MEMORY_ERROR;
    }
  res->pkey[res->ncerts] = pkey;
  return 0;

}

/**
 * gnutls_certificate_set_x509_key:
 * @res: is a #gnutls_certificate_credentials_t structure.
 * @cert_list: contains a certificate list (path) for the specified private key
 * @cert_list_size: holds the size of the certificate list
 * @key: is a #gnutls_x509_privkey_t key
 *
 * This function sets a certificate/private key pair in the
 * gnutls_certificate_credentials_t structure.  This function may be
 * called more than once, in case multiple keys/certificates exist for
 * the server.  For clients that wants to send more than their own end
 * entity certificate (e.g., also an intermediate CA cert) then put
 * the certificate chain in @cert_list.
 *
 * Returns: %GNUTLS_E_SUCCESS (0) on success, or a negative error code.
 *
 * Since: 2.4.0
 **/
int
gnutls_certificate_set_x509_key (gnutls_certificate_credentials_t res,
                                 gnutls_x509_crt_t * cert_list,
                                 int cert_list_size,
                                 gnutls_x509_privkey_t key)
{
  int ret, i;
  gnutls_privkey_t pkey;
  gnutls_pcert_st *pcerts = NULL;
  gnutls_str_array_t names;
  
  _gnutls_str_array_init(&names);

  /* this should be first
   */
  ret = gnutls_privkey_init (&pkey);
  if (ret < 0)
    {
      gnutls_assert ();
      return ret;
    }

  if (res->pin.cb)
    gnutls_privkey_set_pin_function(pkey, res->pin.cb, res->pin.data);

  ret = gnutls_privkey_import_x509 (pkey, key, GNUTLS_PRIVKEY_IMPORT_COPY);
  if (ret < 0)
    {
      gnutls_assert ();
      return ret;
    }

  ret = certificate_credentials_append_pkey (res, pkey);
  if (ret < 0)
    {
      gnutls_assert ();
      return ret;
    }

  /* load certificates */
  pcerts = gnutls_malloc (sizeof (gnutls_pcert_st) * cert_list_size);
  if (pcerts == NULL)
    {
      gnutls_assert ();
      return GNUTLS_E_MEMORY_ERROR;
    }

  ret = get_x509_name(cert_list[0], &names);
  if (ret < 0)
    return gnutls_assert_val(ret);

  for (i = 0; i < cert_list_size; i++)
    {
      ret = gnutls_pcert_import_x509 (&pcerts[i], cert_list[i], 0);
      if (ret < 0)
        {
          gnutls_assert ();
          goto cleanup;
        }
    }

  ret = certificate_credential_append_crt_list (res, names, pcerts, cert_list_size);
  if (ret < 0)
    {
      gnutls_assert ();
      goto cleanup;
    }

  res->ncerts++;

  if ((ret = _gnutls_check_key_cert_match (res)) < 0)
    {
      gnutls_assert ();
      return ret;
    }

  return 0;
  
cleanup:
  _gnutls_str_array_clear(&names);
  return ret;
}

/**
 * gnutls_certificate_set_key:
 * @res: is a #gnutls_certificate_credentials_t structure.
 * @names: is an array of DNS name of the certificate (NULL if none)
 * @names_size: holds the size of the names list
 * @pcert_list: contains a certificate list (path) for the specified private key
 * @pcert_list_size: holds the size of the certificate list
 * @key: is a #gnutls_privkey_t key
 *
 * This function sets a certificate/private key pair in the
 * gnutls_certificate_credentials_t structure.  This function may be
 * called more than once, in case multiple keys/certificates exist for
 * the server.  For clients that wants to send more than its own end
 * entity certificate (e.g., also an intermediate CA cert) then put
 * the certificate chain in @pcert_list. The @pcert_list and @key will
 * become part of the credentials structure and must not
 * be deallocated. They will be automatically deallocated when @res
 * is deinitialized.
 *
 * Returns: %GNUTLS_E_SUCCESS (0) on success, or a negative error code.
 *
 * Since: 3.0
 **/
int
gnutls_certificate_set_key (gnutls_certificate_credentials_t res,
                            const char** names,
                            int names_size,
                            gnutls_pcert_st * pcert_list,
                            int pcert_list_size,
                            gnutls_privkey_t key)
{
  int ret, i;
  gnutls_str_array_t str_names;
  
  _gnutls_str_array_init(&str_names);

  if (names != NULL && names_size > 0)
    {
      for (i=0;i<names_size;i++)
        {
          ret = _gnutls_str_array_append(&str_names, names[i], strlen(names[i]));
          if (ret < 0)
            {
              ret = gnutls_assert_val(ret);
              goto cleanup;
            }
        }
    }

  if (res->pin.cb)
    gnutls_privkey_set_pin_function(key, res->pin.cb, res->pin.data);

  ret = certificate_credentials_append_pkey (res, key);
  if (ret < 0)
    {
      gnutls_assert ();
      goto cleanup;
    }

  ret = certificate_credential_append_crt_list (res, str_names, pcert_list, pcert_list_size);
  if (ret < 0)
    {
      gnutls_assert ();
      goto cleanup;
    }

  res->ncerts++;

  if ((ret = _gnutls_check_key_cert_match (res)) < 0)
    {
      gnutls_assert ();
      return ret;
    }

  return 0;
  
cleanup:
  _gnutls_str_array_clear(&str_names);
  return ret;
}

/**
 * gnutls_certificate_set_x509_key_file:
 * @res: is a #gnutls_certificate_credentials_t structure.
 * @certfile: is a file that containing the certificate list (path) for
 *   the specified private key, in PKCS7 format, or a list of certificates
 * @keyfile: is a file that contains the private key
 * @type: is PEM or DER
 *
 * This function sets a certificate/private key pair in the
 * gnutls_certificate_credentials_t structure.  This function may be
 * called more than once, in case multiple keys/certificates exist for
 * the server.  For clients that need to send more than its own end
 * entity certificate, e.g., also an intermediate CA cert, then the
 * @certfile must contain the ordered certificate chain.
 *
 * This function can also accept URLs at @keyfile and @certfile. In that case it
 * will import the private key and certificate indicated by the URLs. Note
 * that the supported URLs are the ones indicated by gnutls_url_is_supported().
 *
 * Returns: %GNUTLS_E_SUCCESS (0) on success, or a negative error code.
 **/
int
gnutls_certificate_set_x509_key_file (gnutls_certificate_credentials_t res,
                                      const char *certfile,
                                      const char *keyfile,
                                      gnutls_x509_crt_fmt_t type)
{
  int ret;

  /* this should be first
   */
  if ((ret = read_key_file (res, keyfile, type)) < 0)
    return ret;

  if ((ret = read_cert_file (res, certfile, type)) < 0)
    return ret;

  res->ncerts++;

  if ((ret = _gnutls_check_key_cert_match (res)) < 0)
    {
      gnutls_assert ();
      return ret;
    }

  return 0;
}

static int
add_new_crt_to_rdn_seq (gnutls_certificate_credentials_t res, gnutls_x509_crt_t* crts,
  unsigned int crt_size)
{
  gnutls_datum_t tmp;
  int ret;
  size_t newsize;
  unsigned char *newdata;
  unsigned i;

  /* Add DN of the last added CAs to the RDN sequence
   * This will be sent to clients when a certificate
   * request message is sent.
   */

  /* FIXME: in case of a client it is not needed
   * to do that. This would save time and memory.
   * However we don't have that information available
   * here.
   * Further, this function is now much more efficient,
   * so optimizing that is less important.
   */

  for (i = 0; i < crt_size; i++)
    {
      if ((ret = gnutls_x509_crt_get_raw_dn (crts[i], &tmp)) < 0)
        {
          gnutls_assert ();
          return ret;
        }

      newsize = res->x509_rdn_sequence.size + 2 + tmp.size;
      if (newsize < res->x509_rdn_sequence.size)
        {
          gnutls_assert ();
          _gnutls_free_datum (&tmp);
          return GNUTLS_E_SHORT_MEMORY_BUFFER;
        }

      newdata = gnutls_realloc (res->x509_rdn_sequence.data, newsize);
      if (newdata == NULL)
        {
          gnutls_assert ();
          _gnutls_free_datum (&tmp);
          return GNUTLS_E_MEMORY_ERROR;
        }

      _gnutls_write_datum16 (newdata + res->x509_rdn_sequence.size, tmp);
      _gnutls_free_datum (&tmp);

      res->x509_rdn_sequence.size = newsize;
      res->x509_rdn_sequence.data = newdata;
    }

  return 0;
}

/* Returns 0 if it's ok to use the gnutls_kx_algorithm_t with this 
 * certificate (uses the KeyUsage field). 
 */
int
_gnutls_check_key_usage (const gnutls_pcert_st* cert, gnutls_kx_algorithm_t alg)
{
  unsigned int key_usage = 0;
  int encipher_type;

  if (cert == NULL)
    {
      gnutls_assert ();
      return GNUTLS_E_INTERNAL_ERROR;
    }

  if (_gnutls_map_kx_get_cred (alg, 1) == GNUTLS_CRD_CERTIFICATE ||
      _gnutls_map_kx_get_cred (alg, 0) == GNUTLS_CRD_CERTIFICATE)
    {

      gnutls_pubkey_get_key_usage(cert->pubkey, &key_usage);

      encipher_type = _gnutls_kx_encipher_type (alg);

      if (key_usage != 0 && encipher_type != CIPHER_IGN)
        {
          /* If key_usage has been set in the certificate
           */

          if (encipher_type == CIPHER_ENCRYPT)
            {
              /* If the key exchange method requires an encipher
               * type algorithm, and key's usage does not permit
               * encipherment, then fail.
               */
              if (!(key_usage & GNUTLS_KEY_KEY_ENCIPHERMENT))
                {
                  gnutls_assert ();
                  return GNUTLS_E_KEY_USAGE_VIOLATION;
                }
            }

          if (encipher_type == CIPHER_SIGN)
            {
              /* The same as above, but for sign only keys
               */
              if (!(key_usage & GNUTLS_KEY_DIGITAL_SIGNATURE))
                {
                  gnutls_assert ();
                  return GNUTLS_E_KEY_USAGE_VIOLATION;
                }
            }
        }
    }
  return 0;
}

static int
parse_pem_ca_mem (gnutls_certificate_credentials_t res,
                  const uint8_t * input_cert, int input_cert_size)
{
  gnutls_x509_crt_t *x509_cert_list;
  unsigned int x509_ncerts;
  gnutls_datum_t tmp;
  int ret;

  tmp.data = (void*)input_cert;
  tmp.size = input_cert_size;

  ret = gnutls_x509_crt_list_import2( &x509_cert_list, &x509_ncerts, &tmp, 
    GNUTLS_X509_FMT_PEM, 0);
  if (ret < 0)
    {
      gnutls_assert();
      return ret;
    }

  if ((ret = add_new_crt_to_rdn_seq (res, x509_cert_list, x509_ncerts)) < 0)
    {
      gnutls_assert();
      goto cleanup;
    }

  ret = gnutls_x509_trust_list_add_cas(res->tlist, x509_cert_list, x509_ncerts, 0);
  if (ret < 0)
    {
      gnutls_assert();
      goto cleanup;
    }

cleanup:
  gnutls_free(x509_cert_list);
  return ret;
}

/* Reads a DER encoded certificate list from memory and stores it to a
 * gnutls_cert structure.  Returns the number of certificates parsed.
 */
static int
parse_der_ca_mem (gnutls_certificate_credentials_t res,
                  const void *input_cert, int input_cert_size)
{
  gnutls_x509_crt_t crt;
  gnutls_datum_t tmp;
  int ret;

  tmp.data = (void*)input_cert;
  tmp.size = input_cert_size;

  ret = gnutls_x509_crt_init( &crt);
  if (ret < 0)
    {
      gnutls_assert();
      return ret;
    }

  ret = gnutls_x509_crt_import( crt, &tmp, GNUTLS_X509_FMT_DER);
  if (ret < 0)
    {
      gnutls_assert();
      goto cleanup;
    }

  if ((ret = add_new_crt_to_rdn_seq (res, &crt, 1)) < 0)
    {
      gnutls_assert();
      goto cleanup;
    }

  ret = gnutls_x509_trust_list_add_cas(res->tlist, &crt, 1, 0);
  if (ret < 0)
    {
      gnutls_assert();
      goto cleanup;
    }

  return ret;

cleanup:
  gnutls_x509_crt_deinit(crt);
  return ret;
}

/**
 * gnutls_certificate_set_x509_trust_mem:
 * @res: is a #gnutls_certificate_credentials_t structure.
 * @ca: is a list of trusted CAs or a DER certificate
 * @type: is DER or PEM
 *
 * This function adds the trusted CAs in order to verify client or
 * server certificates. In case of a client this is not required to be
 * called if the certificates are not verified using
 * gnutls_certificate_verify_peers2().  This function may be called
 * multiple times.
 *
 * In case of a server the CAs set here will be sent to the client if
 * a certificate request is sent. This can be disabled using
 * gnutls_certificate_send_x509_rdn_sequence().
 *
 * Returns: the number of certificates processed or a negative error code
 * on error.
 **/
int
gnutls_certificate_set_x509_trust_mem (gnutls_certificate_credentials_t res,
                                       const gnutls_datum_t * ca,
                                       gnutls_x509_crt_fmt_t type)
{
  int ret;

  if (type == GNUTLS_X509_FMT_DER)
    ret = parse_der_ca_mem (res,
                            ca->data, ca->size);
  else
    ret = parse_pem_ca_mem (res,
                            ca->data, ca->size);

  if (ret == GNUTLS_E_NO_CERTIFICATE_FOUND)
    return 0;

  return ret;
}

/**
 * gnutls_certificate_set_x509_trust:
 * @res: is a #gnutls_certificate_credentials_t structure.
 * @ca_list: is a list of trusted CAs
 * @ca_list_size: holds the size of the CA list
 *
 * This function adds the trusted CAs in order to verify client
 * or server certificates. In case of a client this is not required
 * to be called if the certificates are not verified using
 * gnutls_certificate_verify_peers2().
 * This function may be called multiple times.
 *
 * In case of a server the CAs set here will be sent to the client if
 * a certificate request is sent. This can be disabled using
 * gnutls_certificate_send_x509_rdn_sequence().
 *
 * Returns: the number of certificates processed or a negative error code
 * on error.
 *
 * Since: 2.4.0
 **/
int
gnutls_certificate_set_x509_trust (gnutls_certificate_credentials_t res,
                                   gnutls_x509_crt_t * ca_list,
                                   int ca_list_size)
{
  int ret, i, j;
  gnutls_x509_crt_t new_list[ca_list_size];

  for (i = 0; i < ca_list_size; i++)
    {
      ret = gnutls_x509_crt_init (&new_list[i]);
      if (ret < 0)
        {
          gnutls_assert ();
          goto cleanup;
        }

      ret = _gnutls_x509_crt_cpy (new_list[i], ca_list[i]);
      if (ret < 0)
        {
          gnutls_assert ();
          goto cleanup;
        }
    }

  if ((ret = add_new_crt_to_rdn_seq (res, new_list, ca_list_size)) < 0)
    {
      gnutls_assert();
      goto cleanup;
    }

  ret = gnutls_x509_trust_list_add_cas(res->tlist, new_list, ca_list_size, 0);
  if (ret < 0)
    {
      gnutls_assert ();
      goto cleanup;
    }

  return ret;

cleanup:
  for (j=0;j<i;i++)
    gnutls_x509_crt_deinit(new_list[j]);

  return ret;
}


/**
 * gnutls_certificate_set_x509_trust_file:
 * @cred: is a #gnutls_certificate_credentials_t structure.
 * @cafile: is a file containing the list of trusted CAs (DER or PEM list)
 * @type: is PEM or DER
 *
 * This function adds the trusted CAs in order to verify client or
 * server certificates. In case of a client this is not required to
 * be called if the certificates are not verified using
 * gnutls_certificate_verify_peers2().  This function may be called
 * multiple times.
 *
 * In case of a server the names of the CAs set here will be sent to
 * the client if a certificate request is sent. This can be disabled
 * using gnutls_certificate_send_x509_rdn_sequence().
 *
 * This function can also accept URLs. In that case it
 * will import all certificates that are marked as trusted. Note
 * that the supported URLs are the ones indicated by gnutls_url_is_supported().
 *
 * Returns: number of certificates processed, or a negative error code on
 * error.
 **/
int
gnutls_certificate_set_x509_trust_file (gnutls_certificate_credentials_t cred,
                                        const char *cafile,
                                        gnutls_x509_crt_fmt_t type)
{
  int ret;
  gnutls_datum_t cas;
  size_t size;

#ifdef ENABLE_PKCS11
  if (strncmp (cafile, "pkcs11:", 7) == 0)
    {
      return read_cas_url (cred, cafile);
    }
#endif

  cas.data = (void*)read_binary_file (cafile, &size);
  if (cas.data == NULL)
    {
      gnutls_assert ();
      return GNUTLS_E_FILE_ERROR;
    }

  cas.size = size;

  ret = gnutls_certificate_set_x509_trust_mem(cred, &cas, type);

  free (cas.data);

  if (ret < 0)
    {
      gnutls_assert ();
      return ret;
    }

  return ret;
}

/**
 * gnutls_certificate_set_x509_system_trust:
 * @cred: is a #gnutls_certificate_credentials_t structure.
 *
 * This function adds the system's default trusted CAs in order to
 * verify client or server certificates.
 *
 * In the case the system is currently unsupported %GNUTLS_E_UNIMPLEMENTED_FEATURE
 * is returned.
 *
 * Returns: the number of certificates processed or a negative error code
 * on error.
 *
 * Since: 3.0
 **/
int
gnutls_certificate_set_x509_system_trust (gnutls_certificate_credentials_t cred)
{
  return gnutls_x509_trust_list_add_system_trust(cred->tlist, 0, 0);
}

static int
parse_pem_crl_mem (gnutls_x509_trust_list_t tlist, 
                   const char * input_crl, unsigned int input_crl_size)
{
  gnutls_x509_crl_t *x509_crl_list;
  unsigned int x509_ncrls;
  gnutls_datum_t tmp;
  int ret;

  tmp.data = (void*)input_crl;
  tmp.size = input_crl_size;

  ret = gnutls_x509_crl_list_import2( &x509_crl_list, &x509_ncrls, &tmp, 
    GNUTLS_X509_FMT_PEM, 0);
  if (ret < 0)
    {
      gnutls_assert();
      return ret;
    }

  ret = gnutls_x509_trust_list_add_crls(tlist, x509_crl_list, x509_ncrls, 0, 0);
  if (ret < 0)
    {
      gnutls_assert();
      goto cleanup;
    }

cleanup:
  gnutls_free(x509_crl_list);
  return ret;
}

/* Reads a DER encoded certificate list from memory and stores it to a
 * gnutls_cert structure. Returns the number of certificates parsed.
 */
static int
parse_der_crl_mem (gnutls_x509_trust_list_t tlist,
                   const void *input_crl, unsigned int input_crl_size)
{
  gnutls_x509_crl_t crl;
  gnutls_datum_t tmp;
  int ret;

  tmp.data = (void*)input_crl;
  tmp.size = input_crl_size;

  ret = gnutls_x509_crl_init( &crl);
  if (ret < 0)
    {
      gnutls_assert();
      return ret;
    }

  ret = gnutls_x509_crl_import( crl, &tmp, GNUTLS_X509_FMT_DER);
  if (ret < 0)
    {
      gnutls_assert();
      goto cleanup;
    }

  ret = gnutls_x509_trust_list_add_crls(tlist, &crl, 1, 0, 0);
  if (ret < 0)
    {
      gnutls_assert();
      goto cleanup;
    }

  return ret;

cleanup:
  gnutls_x509_crl_deinit(crl);
  return ret;

}


/* Reads a DER or PEM CRL from memory
 */
static int
read_crl_mem (gnutls_certificate_credentials_t res, const void *crl,
              int crl_size, gnutls_x509_crt_fmt_t type)
{
  int ret;

  if (type == GNUTLS_X509_FMT_DER)
    ret = parse_der_crl_mem (res->tlist, crl, crl_size);
  else
    ret = parse_pem_crl_mem (res->tlist, crl, crl_size);

  if (ret < 0)
    {
      gnutls_assert ();
    }

  return ret;
}

/**
 * gnutls_certificate_set_x509_crl_mem:
 * @res: is a #gnutls_certificate_credentials_t structure.
 * @CRL: is a list of trusted CRLs. They should have been verified before.
 * @type: is DER or PEM
 *
 * This function adds the trusted CRLs in order to verify client or
 * server certificates.  In case of a client this is not required to
 * be called if the certificates are not verified using
 * gnutls_certificate_verify_peers2().  This function may be called
 * multiple times.
 *
 * Returns: number of CRLs processed, or a negative error code on error.
 **/
int
gnutls_certificate_set_x509_crl_mem (gnutls_certificate_credentials_t res,
                                     const gnutls_datum_t * CRL,
                                     gnutls_x509_crt_fmt_t type)
{
  return read_crl_mem (res, CRL->data, CRL->size, type);
}

/**
 * gnutls_certificate_set_x509_crl:
 * @res: is a #gnutls_certificate_credentials_t structure.
 * @crl_list: is a list of trusted CRLs. They should have been verified before.
 * @crl_list_size: holds the size of the crl_list
 *
 * This function adds the trusted CRLs in order to verify client or
 * server certificates.  In case of a client this is not required to
 * be called if the certificates are not verified using
 * gnutls_certificate_verify_peers2().  This function may be called
 * multiple times.
 *
 * Returns: %GNUTLS_E_SUCCESS (0) on success, or a negative error code.
 *
 * Since: 2.4.0
 **/
int
gnutls_certificate_set_x509_crl (gnutls_certificate_credentials_t res,
                                 gnutls_x509_crl_t * crl_list,
                                 int crl_list_size)
{
  int ret, i, j;
  gnutls_x509_crl_t new_crl[crl_list_size];

  for (i = 0; i < crl_list_size; i++)
    {
      ret = gnutls_x509_crl_init (&new_crl[i]);
      if (ret < 0)
        {
          gnutls_assert ();
          goto cleanup;
        }

      ret = _gnutls_x509_crl_cpy (new_crl[i], crl_list[i]);
      if (ret < 0)
        {
          gnutls_assert ();
          goto cleanup;
        }
    }

  ret = gnutls_x509_trust_list_add_crls(res->tlist, new_crl, crl_list_size, 0, 0);
  if (ret < 0)
    {
      gnutls_assert ();
      goto cleanup;
    }

  return ret;

cleanup:
  for (j=0;j<i;j++)
    gnutls_x509_crl_deinit(new_crl[j]);

  return ret;
}

/**
 * gnutls_certificate_set_x509_crl_file:
 * @res: is a #gnutls_certificate_credentials_t structure.
 * @crlfile: is a file containing the list of verified CRLs (DER or PEM list)
 * @type: is PEM or DER
 *
 * This function adds the trusted CRLs in order to verify client or server
 * certificates.  In case of a client this is not required
 * to be called if the certificates are not verified using
 * gnutls_certificate_verify_peers2().
 * This function may be called multiple times.
 *
 * Returns: number of CRLs processed or a negative error code on error.
 **/
int
gnutls_certificate_set_x509_crl_file (gnutls_certificate_credentials_t res,
                                      const char *crlfile,
                                      gnutls_x509_crt_fmt_t type)
{
  int ret;
  size_t size;
  char *data = (void*)read_binary_file (crlfile, &size);

  if (data == NULL)
    {
      gnutls_assert ();
      return GNUTLS_E_FILE_ERROR;
    }

  if (type == GNUTLS_X509_FMT_DER)
    ret = parse_der_crl_mem (res->tlist, data, size);
  else
    ret = parse_pem_crl_mem (res->tlist, data, size);

  free (data);

  if (ret < 0)
    {
      gnutls_assert ();
      return ret;
    }

  return ret;
}

#include <gnutls/pkcs12.h>


/**
 * gnutls_certificate_set_x509_simple_pkcs12_file:
 * @res: is a #gnutls_certificate_credentials_t structure.
 * @pkcs12file: filename of file containing PKCS#12 blob.
 * @type: is PEM or DER of the @pkcs12file.
 * @password: optional password used to decrypt PKCS#12 file, bags and keys.
 *
 * This function sets a certificate/private key pair and/or a CRL in
 * the gnutls_certificate_credentials_t structure.  This function may
 * be called more than once (in case multiple keys/certificates exist
 * for the server).
 *
 * PKCS#12 files with a MAC, encrypted bags and PKCS #8
 * private keys are supported. However,
 * only password based security, and the same password for all
 * operations, are supported.
 *
 * PKCS#12 file may contain many keys and/or certificates, and there
 * is no way to identify which key/certificate pair you want.  You
 * should make sure the PKCS#12 file only contain one key/certificate
 * pair and/or one CRL.
 *
 * It is believed that the limitations of this function is acceptable
 * for most usage, and that any more flexibility would introduce
 * complexity that would make it harder to use this functionality at
 * all.
 *
 * Returns: %GNUTLS_E_SUCCESS (0) on success, or a negative error code.
 **/
int
  gnutls_certificate_set_x509_simple_pkcs12_file
  (gnutls_certificate_credentials_t res, const char *pkcs12file,
   gnutls_x509_crt_fmt_t type, const char *password)
{
  gnutls_datum_t p12blob;
  size_t size;
  int ret;

  p12blob.data = (void*)read_binary_file (pkcs12file, &size);
  p12blob.size = (unsigned int) size;
  if (p12blob.data == NULL)
    {
      gnutls_assert ();
      return GNUTLS_E_FILE_ERROR;
    }

  ret =
    gnutls_certificate_set_x509_simple_pkcs12_mem (res, &p12blob, type,
                                                   password);
  free (p12blob.data);

  return ret;
}

/**
 * gnutls_certificate_set_x509_simple_pkcs12_mem:
 * @res: is a #gnutls_certificate_credentials_t structure.
 * @p12blob: the PKCS#12 blob.
 * @type: is PEM or DER of the @pkcs12file.
 * @password: optional password used to decrypt PKCS#12 file, bags and keys.
 *
 * This function sets a certificate/private key pair and/or a CRL in
 * the gnutls_certificate_credentials_t structure.  This function may
 * be called more than once (in case multiple keys/certificates exist
 * for the server).
 *
 * Encrypted PKCS#12 bags and PKCS#8 private keys are supported.  However,
 * only password based security, and the same password for all
 * operations, are supported.
 *
 * PKCS#12 file may contain many keys and/or certificates, and there
 * is no way to identify which key/certificate pair you want.  You
 * should make sure the PKCS#12 file only contain one key/certificate
 * pair and/or one CRL.
 *
 * It is believed that the limitations of this function is acceptable
 * for most usage, and that any more flexibility would introduce
 * complexity that would make it harder to use this functionality at
 * all.
 *
 * Returns: %GNUTLS_E_SUCCESS (0) on success, or a negative error code.
 *
 * Since: 2.8.0
 **/
int
  gnutls_certificate_set_x509_simple_pkcs12_mem
  (gnutls_certificate_credentials_t res, const gnutls_datum_t * p12blob,
   gnutls_x509_crt_fmt_t type, const char *password)
{
  gnutls_pkcs12_t p12;
  gnutls_x509_privkey_t key = NULL;
  gnutls_x509_crt_t *chain = NULL;
  gnutls_x509_crl_t crl = NULL;
  unsigned int chain_size = 0, i;
  int ret;

  ret = gnutls_pkcs12_init (&p12);
  if (ret < 0)
    {
      gnutls_assert ();
      return ret;
    }

  ret = gnutls_pkcs12_import (p12, p12blob, type, 0);
  if (ret < 0)
    {
      gnutls_assert ();
      gnutls_pkcs12_deinit (p12);
      return ret;
    }

  if (password)
    {
      ret = gnutls_pkcs12_verify_mac (p12, password);
      if (ret < 0)
        {
          gnutls_assert ();
          gnutls_pkcs12_deinit (p12);
          return ret;
        }
    }

  ret = gnutls_pkcs12_simple_parse (p12, password, &key, &chain, &chain_size, 
                             NULL, NULL, &crl, 0);
  gnutls_pkcs12_deinit (p12);
  if (ret < 0)
    {
      gnutls_assert ();
      return ret;
    }

  if (key && chain)
    {
      ret = gnutls_certificate_set_x509_key (res, chain, chain_size, key);
      if (ret < 0)
        {
          gnutls_assert ();
          goto done;
        }
    }
  else
    {
      gnutls_assert();
      ret = GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE;
      goto done;
    }

  if (crl)
    {
      ret = gnutls_certificate_set_x509_crl (res, &crl, 1);
      if (ret < 0)
        {
          gnutls_assert ();
          goto done;
        }
    }

  ret = 0;

done:
  if (chain)
    {
      for (i=0;i<chain_size;i++)
        gnutls_x509_crt_deinit (chain[i]);
      gnutls_free(chain);
    }
  if (key)
    gnutls_x509_privkey_deinit (key);
  if (crl)
    gnutls_x509_crl_deinit (crl);

  return ret;
}



/**
 * gnutls_certificate_free_crls:
 * @sc: is a #gnutls_certificate_credentials_t structure.
 *
 * This function will delete all the CRLs associated
 * with the given credentials.
 **/
void
gnutls_certificate_free_crls (gnutls_certificate_credentials_t sc)
{
  /* do nothing for now */
  return;
}

/**
 * gnutls_certificate_credentials_t:
 * @cred: is a #gnutls_certificate_credentials_t structure.
 * @fn: A PIN callback
 * @userdata: Data to be passed in the callback
 *
 * This function will set a callback function to be used when
 * required to access a protected object. This function overrides any other
 * global PIN functions.
 *
 * Note that this function must be called right after initialization
 * to have effect.
 *
 * Since: 3.1.0
 **/
void gnutls_certificate_set_pin_function (gnutls_certificate_credentials_t cred,
                                          gnutls_pin_callback_t fn, void *userdata)
{
  cred->pin.cb = fn;
  cred->pin.data = userdata;
}