text: /*
   * Copyright 2009 Henri Verbeet for CodeWeavers
   * Copyright 2018 Hans Leidekker for CodeWeavers
   *
   * This library 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 2.1 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 library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
   *
   */
  
  #include "config.h"
  #include "wine/port.h"
  
  #include <stdarg.h>
  #ifdef HAVE_GNUTLS_CIPHER_INIT
  #include <gnutls/gnutls.h>
  #include <gnutls/crypto.h>
  #include <gnutls/abstract.h>
  #endif
  
  #include "ntstatus.h"
  #define WIN32_NO_STATUS
  #include "windef.h"
  #include "winbase.h"
  #include "ntsecapi.h"
  #include "wincrypt.h"
  #include "bcrypt.h"
  
  #include "bcrypt_internal.h"
  
  #include "wine/debug.h"
  #include "wine/heap.h"
  #include "wine/unicode.h"
  
  #ifdef HAVE_GNUTLS_CIPHER_INIT
  WINE_DEFAULT_DEBUG_CHANNEL(bcrypt);
  WINE_DECLARE_DEBUG_CHANNEL(winediag);
  
  #if GNUTLS_VERSION_MAJOR < 3
  #define GNUTLS_CIPHER_AES_192_CBC 92
  #define GNUTLS_CIPHER_AES_128_GCM 93
  #define GNUTLS_CIPHER_AES_256_GCM 94
  #define GNUTLS_PK_ECC 4
  
  #define GNUTLS_CURVE_TO_BITS(curve) (unsigned int)(((unsigned int)1<<31)|((unsigned int)(curve)))
  
  typedef enum
  {
      GNUTLS_ECC_CURVE_INVALID,
      GNUTLS_ECC_CURVE_SECP224R1,
      GNUTLS_ECC_CURVE_SECP256R1,
      GNUTLS_ECC_CURVE_SECP384R1,
      GNUTLS_ECC_CURVE_SECP521R1,
  } gnutls_ecc_curve_t;
  #endif
  
  /* Not present in gnutls version < 3.0 */
  static int (*pgnutls_cipher_tag)(gnutls_cipher_hd_t, void *, size_t);
  static int (*pgnutls_cipher_add_auth)(gnutls_cipher_hd_t, const void *, size_t);
  static gnutls_sign_algorithm_t (*pgnutls_pk_to_sign)(gnutls_pk_algorithm_t, gnutls_digest_algorithm_t);
  static int (*pgnutls_pubkey_import_ecc_raw)(gnutls_pubkey_t, gnutls_ecc_curve_t,
                                              const gnutls_datum_t *, const gnutls_datum_t *);
  static int (*pgnutls_privkey_import_ecc_raw)(gnutls_privkey_t, gnutls_ecc_curve_t, const gnutls_datum_t *,
                                               const gnutls_datum_t *, const gnutls_datum_t *);
  static int (*pgnutls_pubkey_verify_hash2)(gnutls_pubkey_t, gnutls_sign_algorithm_t, unsigned int,
                                            const gnutls_datum_t *, const gnutls_datum_t *);
  
  /* Not present in gnutls version < 2.11.0 */
  static int (*pgnutls_pubkey_import_rsa_raw)(gnutls_pubkey_t, const gnutls_datum_t *, const gnutls_datum_t *);
  
  /* Not present in gnutls version < 2.12.0 */
  static int (*pgnutls_pubkey_import_dsa_raw)(gnutls_pubkey_t, const gnutls_datum_t *, const gnutls_datum_t *,
                                              const gnutls_datum_t *, const gnutls_datum_t *);
  
  /* Not present in gnutls version < 3.3.0 */
  static int (*pgnutls_privkey_export_ecc_raw)(gnutls_privkey_t, gnutls_ecc_curve_t *,
                                               gnutls_datum_t *, gnutls_datum_t *, gnutls_datum_t *);
  static int (*pgnutls_privkey_export_rsa_raw)(gnutls_privkey_t, gnutls_datum_t *, gnutls_datum_t *, gnutls_datum_t *,
                                               gnutls_datum_t *, gnutls_datum_t *, gnutls_datum_t *, gnutls_datum_t *,
                                               gnutls_datum_t *);
  static int (*pgnutls_privkey_export_dsa_raw)(gnutls_privkey_t, gnutls_datum_t *, gnutls_datum_t *, gnutls_datum_t *,
                                               gnutls_datum_t *, gnutls_datum_t *);
  static int (*pgnutls_privkey_generate)(gnutls_privkey_t, gnutls_pk_algorithm_t, unsigned int, unsigned int);
  
  /* Not present in gnutls version < 3.6.0 */
  static int (*pgnutls_decode_rs_value)(const gnutls_datum_t *, gnutls_datum_t *, gnutls_datum_t *);
  
  static void *libgnutls_handle;
  #define MAKE_FUNCPTR(f) static typeof(f) * p##f
  MAKE_FUNCPTR(gnutls_cipher_decrypt2);
  MAKE_FUNCPTR(gnutls_cipher_deinit);
  MAKE_FUNCPTR(gnutls_cipher_encrypt2);
  MAKE_FUNCPTR(gnutls_cipher_init);
  MAKE_FUNCPTR(gnutls_global_deinit);
  MAKE_FUNCPTR(gnutls_global_init);
  MAKE_FUNCPTR(gnutls_global_set_log_function);
  MAKE_FUNCPTR(gnutls_global_set_log_level);
  MAKE_FUNCPTR(gnutls_perror);
  MAKE_FUNCPTR(gnutls_privkey_deinit);
  MAKE_FUNCPTR(gnutls_privkey_import_dsa_raw);
  MAKE_FUNCPTR(gnutls_privkey_init);
  MAKE_FUNCPTR(gnutls_privkey_sign_hash);
  MAKE_FUNCPTR(gnutls_pubkey_deinit);
  MAKE_FUNCPTR(gnutls_pubkey_init);
  #undef MAKE_FUNCPTR
  
  static int compat_gnutls_cipher_tag(gnutls_cipher_hd_t handle, void *tag, size_t tag_size)
  {
      return GNUTLS_E_UNKNOWN_CIPHER_TYPE;
  }
  
  static int compat_gnutls_cipher_add_auth(gnutls_cipher_hd_t handle, const void *ptext, size_t ptext_size)
  {
      return GNUTLS_E_UNKNOWN_CIPHER_TYPE;
  }
  
  static int compat_gnutls_pubkey_import_ecc_raw(gnutls_pubkey_t key, gnutls_ecc_curve_t curve,
                                                 const gnutls_datum_t *x, const gnutls_datum_t *y)
  {
      return GNUTLS_E_UNKNOWN_PK_ALGORITHM;
  }
  
  static int compat_gnutls_privkey_export_rsa_raw(gnutls_privkey_t key, gnutls_datum_t *m, gnutls_datum_t *e,
                                                  gnutls_datum_t *d, gnutls_datum_t *p, gnutls_datum_t *q,
                                                  gnutls_datum_t *u, gnutls_datum_t *e1, gnutls_datum_t *e2)
  {
      return GNUTLS_E_UNKNOWN_PK_ALGORITHM;
  }
  
  static int compat_gnutls_privkey_export_ecc_raw(gnutls_privkey_t key, gnutls_ecc_curve_t *curve,
                                                  gnutls_datum_t *x, gnutls_datum_t *y, gnutls_datum_t *k)
  {
      return GNUTLS_E_UNKNOWN_PK_ALGORITHM;
  }
  
  static int compat_gnutls_privkey_import_ecc_raw(gnutls_privkey_t key, gnutls_ecc_curve_t curve,
                                                  const gnutls_datum_t *x, const gnutls_datum_t *y,
                                                  const gnutls_datum_t *k)
  {
      return GNUTLS_E_UNKNOWN_PK_ALGORITHM;
  }
  
  static int compat_gnutls_privkey_export_dsa_raw(gnutls_privkey_t key, gnutls_datum_t *p, gnutls_datum_t *q,
                                                  gnutls_datum_t *g, gnutls_datum_t *y, gnutls_datum_t *x)
  {
      return GNUTLS_E_UNKNOWN_PK_ALGORITHM;
  }
  
  static gnutls_sign_algorithm_t compat_gnutls_pk_to_sign(gnutls_pk_algorithm_t pk, gnutls_digest_algorithm_t hash)
  {
      return GNUTLS_SIGN_UNKNOWN;
  }
  
  static int compat_gnutls_pubkey_verify_hash2(gnutls_pubkey_t key, gnutls_sign_algorithm_t algo,
                                               unsigned int flags, const gnutls_datum_t *hash,
                                               const gnutls_datum_t *signature)
  {
      return GNUTLS_E_UNKNOWN_PK_ALGORITHM;
  }
  
  static int compat_gnutls_pubkey_import_rsa_raw(gnutls_pubkey_t key, const gnutls_datum_t *m, const gnutls_datum_t *e)
  {
      return GNUTLS_E_UNKNOWN_PK_ALGORITHM;
  }
  
  static int compat_gnutls_pubkey_import_dsa_raw(gnutls_pubkey_t key, const gnutls_datum_t *p, const gnutls_datum_t *q,
                                                 const gnutls_datum_t *g, const gnutls_datum_t *y)
  {
      return GNUTLS_E_UNKNOWN_PK_ALGORITHM;
  }
  
  static int compat_gnutls_privkey_generate(gnutls_privkey_t key, gnutls_pk_algorithm_t algo, unsigned int bits,
                                            unsigned int flags)
  {
      return GNUTLS_E_UNKNOWN_PK_ALGORITHM;
  }
  
  static int compat_gnutls_decode_rs_value(const gnutls_datum_t * sig_value, gnutls_datum_t * r, gnutls_datum_t * s)
  {
      return GNUTLS_E_INTERNAL_ERROR;
  }
  
  static void gnutls_log( int level, const char *msg )
  {
      TRACE( "<%d> %s", level, msg );
  }
  
  BOOL gnutls_initialize(void)
  {
      int ret;
  
      if (!(libgnutls_handle = dlopen( SONAME_LIBGNUTLS, RTLD_NOW )))
      {
          ERR_(winediag)( "failed to load libgnutls, no support for encryption\n" );
          return FALSE;
      }
  
  #define LOAD_FUNCPTR(f) \
      if (!(p##f = dlsym( libgnutls_handle, #f ))) \
      { \
          ERR( "failed to load %s\n", #f ); \
          goto fail; \
      }
  
      LOAD_FUNCPTR(gnutls_cipher_decrypt2)
      LOAD_FUNCPTR(gnutls_cipher_deinit)
      LOAD_FUNCPTR(gnutls_cipher_encrypt2)
      LOAD_FUNCPTR(gnutls_cipher_init)
      LOAD_FUNCPTR(gnutls_global_deinit)
      LOAD_FUNCPTR(gnutls_global_init)
      LOAD_FUNCPTR(gnutls_global_set_log_function)
      LOAD_FUNCPTR(gnutls_global_set_log_level)
      LOAD_FUNCPTR(gnutls_perror)
      LOAD_FUNCPTR(gnutls_privkey_deinit);
      LOAD_FUNCPTR(gnutls_privkey_import_dsa_raw);
      LOAD_FUNCPTR(gnutls_privkey_init);
      LOAD_FUNCPTR(gnutls_privkey_sign_hash);
      LOAD_FUNCPTR(gnutls_pubkey_deinit);
      LOAD_FUNCPTR(gnutls_pubkey_init);
  #undef LOAD_FUNCPTR
  
      if (!(pgnutls_cipher_tag = dlsym( libgnutls_handle, "gnutls_cipher_tag" )))
      {
          WARN("gnutls_cipher_tag not found\n");
          pgnutls_cipher_tag = compat_gnutls_cipher_tag;
      }
      if (!(pgnutls_cipher_add_auth = dlsym( libgnutls_handle, "gnutls_cipher_add_auth" )))
      {
          WARN("gnutls_cipher_add_auth not found\n");
          pgnutls_cipher_add_auth = compat_gnutls_cipher_add_auth;
      }
  
      if ((ret = pgnutls_global_init()) != GNUTLS_E_SUCCESS)
      {
          pgnutls_perror( ret );
          goto fail;
      }
      if (!(pgnutls_pubkey_import_ecc_raw = dlsym( libgnutls_handle, "gnutls_pubkey_import_ecc_raw" )))
      {
          WARN("gnutls_pubkey_import_ecc_raw not found\n");
          pgnutls_pubkey_import_ecc_raw = compat_gnutls_pubkey_import_ecc_raw;
      }
      if (!(pgnutls_privkey_export_rsa_raw = dlsym( libgnutls_handle, "gnutls_privkey_export_rsa_raw" )))
      {
          WARN("gnutls_privkey_export_rsa_raw not found\n");
          pgnutls_privkey_export_rsa_raw = compat_gnutls_privkey_export_rsa_raw;
      }
      if (!(pgnutls_privkey_export_ecc_raw = dlsym( libgnutls_handle, "gnutls_privkey_export_ecc_raw" )))
      {
          WARN("gnutls_privkey_export_ecc_raw not found\n");
          pgnutls_privkey_export_ecc_raw = compat_gnutls_privkey_export_ecc_raw;
      }
      if (!(pgnutls_privkey_import_ecc_raw = dlsym( libgnutls_handle, "gnutls_privkey_import_ecc_raw" )))
      {
          WARN("gnutls_privkey_import_ecc_raw not found\n");
          pgnutls_privkey_import_ecc_raw = compat_gnutls_privkey_import_ecc_raw;
      }
      if (!(pgnutls_privkey_export_dsa_raw = dlsym( libgnutls_handle, "gnutls_privkey_export_dsa_raw" )))
      {
          WARN("gnutls_privkey_export_dsa_raw not found\n");
          pgnutls_privkey_export_dsa_raw = compat_gnutls_privkey_export_dsa_raw;
      }
      if (!(pgnutls_pk_to_sign = dlsym( libgnutls_handle, "gnutls_pk_to_sign" )))
      {
          WARN("gnutls_pk_to_sign not found\n");
          pgnutls_pk_to_sign = compat_gnutls_pk_to_sign;
      }
      if (!(pgnutls_pubkey_verify_hash2 = dlsym( libgnutls_handle, "gnutls_pubkey_verify_hash2" )))
      {
          WARN("gnutls_pubkey_verify_hash2 not found\n");
          pgnutls_pubkey_verify_hash2 = compat_gnutls_pubkey_verify_hash2;
      }
      if (!(pgnutls_pubkey_import_rsa_raw = dlsym( libgnutls_handle, "gnutls_pubkey_import_rsa_raw" )))
      {
          WARN("gnutls_pubkey_import_rsa_raw not found\n");
          pgnutls_pubkey_import_rsa_raw = compat_gnutls_pubkey_import_rsa_raw;
      }
      if (!(pgnutls_pubkey_import_dsa_raw = dlsym( libgnutls_handle, "gnutls_pubkey_import_dsa_raw" )))
      {
          WARN("gnutls_pubkey_import_dsa_raw not found\n");
          pgnutls_pubkey_import_dsa_raw = compat_gnutls_pubkey_import_dsa_raw;
      }
      if (!(pgnutls_privkey_generate = dlsym( libgnutls_handle, "gnutls_privkey_generate" )))
      {
          WARN("gnutls_privkey_generate not found\n");
          pgnutls_privkey_generate = compat_gnutls_privkey_generate;
      }
      if (!(pgnutls_decode_rs_value = dlsym( libgnutls_handle, "gnutls_decode_rs_value" )))
      {
          WARN("gnutls_decode_rs_value not found\n");
          pgnutls_decode_rs_value = compat_gnutls_decode_rs_value;
      }
  
      if (TRACE_ON( bcrypt ))
      {
          pgnutls_global_set_log_level( 4 );
          pgnutls_global_set_log_function( gnutls_log );
      }
  
      return TRUE;
  
  fail:
      dlclose( libgnutls_handle );
      libgnutls_handle = NULL;
      return FALSE;
  }
  
  void gnutls_uninitialize(void)
  {
      pgnutls_global_deinit();
      dlclose( libgnutls_handle );
      libgnutls_handle = NULL;
  }
  
  struct buffer
  {
      BYTE  *buffer;
      DWORD  length;
      DWORD  pos;
      BOOL   error;
  };
  
  static void buffer_init( struct buffer *buffer )
  {
      buffer->buffer = NULL;
      buffer->length = 0;
      buffer->pos    = 0;
      buffer->error  = FALSE;
  }
  
  static void buffer_free( struct buffer *buffer )
  {
      heap_free( buffer->buffer );
  }
  
  static void buffer_append( struct buffer *buffer, BYTE *data, DWORD len )
  {
      if (!len) return;
  
      if (buffer->pos + len > buffer->length)
      {
          DWORD new_length = max( max( buffer->pos + len, buffer->length * 2 ), 64 );
          BYTE *new_buffer;
  
          if (!(new_buffer = heap_realloc( buffer->buffer, new_length )))
          {
              ERR( "out of memory\n" );
              buffer->error = TRUE;
              return;
          }
  
          buffer->buffer = new_buffer;
          buffer->length = new_length;
      }
  
      memcpy( &buffer->buffer[buffer->pos], data, len );
      buffer->pos += len;
  }
  
  static void buffer_append_byte( struct buffer *buffer, BYTE value )
  {
      buffer_append( buffer, &value, sizeof(value) );
  }
  
  static void buffer_append_asn1_length( struct buffer *buffer, DWORD length )
  {
      DWORD num_bytes;
  
      if (length < 128)
      {
          buffer_append_byte( buffer, length );
          return;
      }
  
      if (length <= 0xff) num_bytes = 1;
      else if (length <= 0xffff) num_bytes = 2;
      else if (length <= 0xffffff) num_bytes = 3;
      else num_bytes = 4;
  
      buffer_append_byte( buffer, 0x80 | num_bytes );
      while (num_bytes--) buffer_append_byte( buffer, length >> (num_bytes * 8) );
  }
  
  static void buffer_append_asn1_integer( struct buffer *buffer, BYTE *data, DWORD len )
  {
      DWORD leading_zero = (*data & 0x80) != 0;
  
      buffer_append_byte( buffer, 0x02 );  /* tag */
      buffer_append_asn1_length( buffer, len + leading_zero );
      if (leading_zero) buffer_append_byte( buffer, 0 );
      buffer_append( buffer, data, len );
  }
  
  static void buffer_append_asn1_sequence( struct buffer *buffer, struct buffer *content )
  {
      if (content->error)
      {
          buffer->error = TRUE;
          return;
      }
  
      buffer_append_byte( buffer, 0x30 );  /* tag */
      buffer_append_asn1_length( buffer, content->pos );
      buffer_append( buffer, content->buffer, content->pos );
  }
  
  static void buffer_append_asn1_r_s( struct buffer *buffer, BYTE *r, DWORD r_len, BYTE *s, DWORD s_len )
  {
      struct buffer value;
  
      buffer_init( &value );
      buffer_append_asn1_integer( &value, r, r_len );
      buffer_append_asn1_integer( &value, s, s_len );
      buffer_append_asn1_sequence( buffer, &value );
      buffer_free( &value );
  }
  
  NTSTATUS key_set_property( struct key *key, const WCHAR *prop, UCHAR *value, ULONG size, ULONG flags )
  {
      if (!strcmpW( prop, BCRYPT_CHAINING_MODE ))
      {
          if (!strcmpW( (WCHAR *)value, BCRYPT_CHAIN_MODE_ECB ))
          {
              key->u.s.mode = MODE_ID_ECB;
              return STATUS_SUCCESS;
          }
          else if (!strcmpW( (WCHAR *)value, BCRYPT_CHAIN_MODE_CBC ))
          {
              key->u.s.mode = MODE_ID_CBC;
              return STATUS_SUCCESS;
          }
          else if (!strcmpW( (WCHAR *)value, BCRYPT_CHAIN_MODE_GCM ))
          {
              key->u.s.mode = MODE_ID_GCM;
              return STATUS_SUCCESS;
          }
          else
          {
              FIXME( "unsupported mode %s\n", debugstr_w((WCHAR *)value) );
              return STATUS_NOT_IMPLEMENTED;
          }
      }
  
      FIXME( "unsupported key property %s\n", debugstr_w(prop) );
      return STATUS_NOT_IMPLEMENTED;
  }
  
  static ULONG get_block_size( struct algorithm *alg )
  {
      ULONG ret = 0, size = sizeof(ret);
      get_alg_property( alg, BCRYPT_BLOCK_LENGTH, (UCHAR *)&ret, sizeof(ret), &size );
      return ret;
  }
  
  NTSTATUS key_symmetric_init( struct key *key, struct algorithm *alg, const UCHAR *secret, ULONG secret_len )
  {
      if (!libgnutls_handle) return STATUS_INTERNAL_ERROR;
  
      switch (alg->id)
      {
      case ALG_ID_AES:
          break;
  
      default:
          FIXME( "algorithm %u not supported\n", alg->id );
          return STATUS_NOT_SUPPORTED;
      }
  
      if (!(key->u.s.block_size = get_block_size( alg ))) return STATUS_INVALID_PARAMETER;
      if (!(key->u.s.secret = heap_alloc( secret_len ))) return STATUS_NO_MEMORY;
      memcpy( key->u.s.secret, secret, secret_len );
      key->u.s.secret_len = secret_len;
  
      key->alg_id         = alg->id;
      key->u.s.mode       = alg->mode;
      key->u.s.handle     = 0;        /* initialized on first use */
      key->u.s.vector     = NULL;
      key->u.s.vector_len = 0;
  
      return STATUS_SUCCESS;
  }
  
  static gnutls_cipher_algorithm_t get_gnutls_cipher( const struct key *key )
  {
      switch (key->alg_id)
      {
      case ALG_ID_AES:
          WARN( "handle block size\n" );
          switch (key->u.s.mode)
          {
          case MODE_ID_GCM:
              if (key->u.s.secret_len == 16) return GNUTLS_CIPHER_AES_128_GCM;
              if (key->u.s.secret_len == 32) return GNUTLS_CIPHER_AES_256_GCM;
              break;
          case MODE_ID_ECB: /* can be emulated with CBC + empty IV */
          case MODE_ID_CBC:
              if (key->u.s.secret_len == 16) return GNUTLS_CIPHER_AES_128_CBC;
              if (key->u.s.secret_len == 24) return GNUTLS_CIPHER_AES_192_CBC;
              if (key->u.s.secret_len == 32) return GNUTLS_CIPHER_AES_256_CBC;
              break;
          default:
              break;
          }
          FIXME( "AES mode %u with key length %u not supported\n", key->u.s.mode, key->u.s.secret_len );
          return GNUTLS_CIPHER_UNKNOWN;
  
      default:
          FIXME( "algorithm %u not supported\n", key->alg_id );
          return GNUTLS_CIPHER_UNKNOWN;
      }
  }
  
  NTSTATUS key_symmetric_set_vector( struct key *key, UCHAR *vector, ULONG vector_len )
  {
      if (key->u.s.handle && (!is_zero_vector( vector, vector_len ) ||
          !is_equal_vector( key->u.s.vector, key->u.s.vector_len, vector, vector_len )))
      {
          TRACE( "invalidating cipher handle\n" );
          pgnutls_cipher_deinit( key->u.s.handle );
          key->u.s.handle = NULL;
      }
  
      heap_free( key->u.s.vector );
      key->u.s.vector = NULL;
      key->u.s.vector_len = 0;
      if (vector)
      {
          if (!(key->u.s.vector = heap_alloc( vector_len ))) return STATUS_NO_MEMORY;
          memcpy( key->u.s.vector, vector, vector_len );
          key->u.s.vector_len = vector_len;
      }
  
      return STATUS_SUCCESS;
  }
  
  static NTSTATUS init_cipher_handle( struct key *key )
  {
      gnutls_cipher_algorithm_t cipher;
      gnutls_datum_t secret, vector;
      int ret;
  
      if (key->u.s.handle) return STATUS_SUCCESS;
      if ((cipher = get_gnutls_cipher( key )) == GNUTLS_CIPHER_UNKNOWN) return STATUS_NOT_SUPPORTED;
  
      secret.data = key->u.s.secret;
      secret.size = key->u.s.secret_len;
  
      vector.data = key->u.s.vector;
      vector.size = key->u.s.vector_len;
  
      if ((ret = pgnutls_cipher_init( &key->u.s.handle, cipher, &secret, key->u.s.vector ? &vector : NULL )))
      {
          pgnutls_perror( ret );
          return STATUS_INTERNAL_ERROR;
      }
  
      return STATUS_SUCCESS;
  }
  
  NTSTATUS key_symmetric_set_auth_data( struct key *key, UCHAR *auth_data, ULONG len )
  {
      NTSTATUS status;
      int ret;
  
      if (!auth_data) return STATUS_SUCCESS;
      if ((status = init_cipher_handle( key ))) return status;
  
      if ((ret = pgnutls_cipher_add_auth( key->u.s.handle, auth_data, len )))
      {
          pgnutls_perror( ret );
          return STATUS_INTERNAL_ERROR;
      }
      return STATUS_SUCCESS;
  }
  
  NTSTATUS key_symmetric_encrypt( struct key *key, const UCHAR *input, ULONG input_len, UCHAR *output, ULONG output_len )
  {
      NTSTATUS status;
      int ret;
  
      if ((status = init_cipher_handle( key ))) return status;
  
      if ((ret = pgnutls_cipher_encrypt2( key->u.s.handle, input, input_len, output, output_len )))
      {
          pgnutls_perror( ret );
          return STATUS_INTERNAL_ERROR;
      }
      return STATUS_SUCCESS;
  }
  
  NTSTATUS key_symmetric_decrypt( struct key *key, const UCHAR *input, ULONG input_len, UCHAR *output, ULONG output_len  )
  {
      NTSTATUS status;
      int ret;
  
      if ((status = init_cipher_handle( key ))) return status;
  
      if ((ret = pgnutls_cipher_decrypt2( key->u.s.handle, input, input_len, output, output_len )))
      {
          pgnutls_perror( ret );
          return STATUS_INTERNAL_ERROR;
      }
      return STATUS_SUCCESS;
  }
  
  NTSTATUS key_symmetric_get_tag( struct key *key, UCHAR *tag, ULONG len )
  {
      NTSTATUS status;
      int ret;
  
      if ((status = init_cipher_handle( key ))) return status;
  
      if ((ret = pgnutls_cipher_tag( key->u.s.handle, tag, len )))
      {
          pgnutls_perror( ret );
          return STATUS_INTERNAL_ERROR;
      }
      return STATUS_SUCCESS;
  }
  
  static NTSTATUS export_gnutls_pubkey_rsa( gnutls_privkey_t gnutls_key, ULONG bitlen, UCHAR **pubkey, ULONG *pubkey_len )
  {
      BCRYPT_RSAKEY_BLOB *rsa_blob;
      gnutls_datum_t m, e;
      UCHAR *dst, *src;
      int ret;
  
      if ((ret = pgnutls_privkey_export_rsa_raw( gnutls_key, &m, &e, NULL, NULL, NULL, NULL, NULL, NULL )))
      {
          pgnutls_perror( ret );
          return STATUS_INTERNAL_ERROR;
      }
  
      if (!(rsa_blob = heap_alloc( sizeof(*rsa_blob) + e.size + m.size )))
      {
          pgnutls_perror( ret );
          free( e.data ); free( m.data );
          return STATUS_NO_MEMORY;
      }
  
      dst = (UCHAR *)(rsa_blob + 1);
      if (e.size == bitlen / 8 + 1 && !e.data[0])
      {
          src = e.data + 1;
          e.size--;
      }
      else src = e.data;
      memcpy( dst, src, e.size );
  
      dst += e.size;
      if (m.size == bitlen / 8 + 1 && !m.data[0])
      {
          src = m.data + 1;
          m.size--;
      }
      else src = m.data;
      memcpy( dst, src, m.size );
  
      rsa_blob->Magic       = BCRYPT_RSAPUBLIC_MAGIC;
      rsa_blob->BitLength   = bitlen;
      rsa_blob->cbPublicExp = e.size;
      rsa_blob->cbModulus   = m.size;
      rsa_blob->cbPrime1    = 0;
      rsa_blob->cbPrime2    = 0;
  
      *pubkey = (UCHAR *)rsa_blob;
      *pubkey_len = sizeof(*rsa_blob) + e.size + m.size;
  
      free( e.data ); free( m.data );
      return STATUS_SUCCESS;
  }
  
  static NTSTATUS export_gnutls_pubkey_ecc( gnutls_privkey_t gnutls_key, UCHAR **pubkey, ULONG *pubkey_len )
  {
      BCRYPT_ECCKEY_BLOB *ecc_blob;
      gnutls_ecc_curve_t curve;
      gnutls_datum_t x, y;
      DWORD magic, size;
      UCHAR *src, *dst;
      int ret;
  
      if ((ret = pgnutls_privkey_export_ecc_raw( gnutls_key, &curve, &x, &y, NULL )))
      {
          pgnutls_perror( ret );
          return STATUS_INTERNAL_ERROR;
      }
  
      switch (curve)
      {
      case GNUTLS_ECC_CURVE_SECP256R1:
          magic = BCRYPT_ECDH_PUBLIC_P256_MAGIC;
          size = 32;
          break;
  
      default:
          FIXME( "curve %u not supported\n", curve );
          free( x.data ); free( y.data );
          return STATUS_NOT_IMPLEMENTED;
      }
  
      if (!(ecc_blob = heap_alloc( sizeof(*ecc_blob) + x.size + y.size )))
      {
          pgnutls_perror( ret );
          free( x.data ); free( y.data );
          return STATUS_NO_MEMORY;
      }
  
      ecc_blob->dwMagic = magic;
      ecc_blob->cbKey   = size;
  
      dst = (UCHAR *)(ecc_blob + 1);
      if (x.size == size + 1) src = x.data + 1;
      else src = x.data;
      memcpy( dst, src, size );
  
      dst += size;
      if (y.size == size + 1) src = y.data + 1;
      else src = y.data;
      memcpy( dst, src, size );
  
      *pubkey = (UCHAR *)ecc_blob;
      *pubkey_len = sizeof(*ecc_blob) + ecc_blob->cbKey * 2;
  
      free( x.data ); free( y.data );
      return STATUS_SUCCESS;
  }
  
  static NTSTATUS export_gnutls_pubkey_dsa( gnutls_privkey_t gnutls_key, ULONG bitlen, UCHAR **pubkey, ULONG *pubkey_len )
  {
      BCRYPT_DSA_KEY_BLOB *dsa_blob;
      gnutls_datum_t p, q, g, y;
      UCHAR *dst, *src;
      int ret;
  
      if ((ret = pgnutls_privkey_export_dsa_raw( gnutls_key, &p, &q, &g, &y, NULL )))
      {
          pgnutls_perror( ret );
          return STATUS_INTERNAL_ERROR;
      }
  
      if (bitlen > 1024)
      {
          FIXME( "bitlen > 1024 not supported\n" );
          return STATUS_NOT_IMPLEMENTED;
      }
  
      if (!(dsa_blob = heap_alloc( sizeof(*dsa_blob) + p.size + g.size + y.size )))
      {
          pgnutls_perror( ret );
          free( p.data ); free( q.data ); free( g.data ); free( y.data );
          return STATUS_NO_MEMORY;
      }
  
      dst = (UCHAR *)(dsa_blob + 1);
      if (p.size == bitlen / 8 + 1 && !p.data[0])
      {
          src = p.data + 1;
          p.size--;
      }
      else src = p.data;
      memcpy( dst, src, p.size );
  
      dst += p.size;
      if (g.size == bitlen / 8 + 1 && !g.data[0])
      {
          src = g.data + 1;
          g.size--;
      }
      else src = g.data;
      memcpy( dst, src, g.size );
  
      dst += g.size;
      if (y.size == bitlen / 8 + 1 && !y.data[0])
      {
          src = y.data + 1;
          y.size--;
      }
      else src = y.data;
      memcpy( dst, src, y.size );
  
      dst = dsa_blob->q;
      if (q.size == sizeof(dsa_blob->q) + 1 && !q.data[0])
      {
          src = q.data + 1;
          q.size--;
      }
      else src = q.data;
      memcpy( dst, src, sizeof(dsa_blob->q) );
  
      dsa_blob->dwMagic = BCRYPT_DSA_PUBLIC_MAGIC;
      dsa_blob->cbKey   = bitlen / 8;
      memset( dsa_blob->Count, 0, sizeof(dsa_blob->Count) ); /* FIXME */
      memset( dsa_blob->Seed, 0, sizeof(dsa_blob->Seed) ); /* FIXME */
  
      *pubkey = (UCHAR *)dsa_blob;
      *pubkey_len = sizeof(*dsa_blob) + p.size + g.size + y.size;
  
      free( p.data ); free( q.data ); free( g.data ); free( y.data );
      return STATUS_SUCCESS;
  }
  
  NTSTATUS key_asymmetric_generate( struct key *key )
  {
      gnutls_pk_algorithm_t pk_alg;
      gnutls_privkey_t handle;
      unsigned int bitlen;
      NTSTATUS status;
      int ret;
  
      if (!libgnutls_handle) return STATUS_INTERNAL_ERROR;
  
      switch (key->alg_id)
      {
      case ALG_ID_RSA:
      case ALG_ID_RSA_SIGN:
          pk_alg = GNUTLS_PK_RSA;
          bitlen = key->u.a.bitlen;
          break;
  
      case ALG_ID_DSA:
          pk_alg = GNUTLS_PK_DSA;
          bitlen = key->u.a.bitlen;
          break;
  
      case ALG_ID_ECDH_P256:
      case ALG_ID_ECDSA_P256:
          pk_alg = GNUTLS_PK_ECC; /* compatible with ECDSA and ECDH */
          bitlen = GNUTLS_CURVE_TO_BITS( GNUTLS_ECC_CURVE_SECP256R1 );
          break;
  
      default:
          FIXME( "algorithm %u not supported\n", key->alg_id );
          return STATUS_NOT_SUPPORTED;
      }
  
      if ((ret = pgnutls_privkey_init( &handle )))
      {
          pgnutls_perror( ret );
          return STATUS_INTERNAL_ERROR;
      }
  
      if ((ret = pgnutls_privkey_generate( handle, pk_alg, bitlen, 0 )))
      {
          pgnutls_perror( ret );
          pgnutls_privkey_deinit( handle );
          return STATUS_INTERNAL_ERROR;
      }
  
      switch (pk_alg)
      {
      case GNUTLS_PK_RSA:
          status = export_gnutls_pubkey_rsa( handle, key->u.a.bitlen, &key->u.a.pubkey, &key->u.a.pubkey_len );
          break;
  
      case GNUTLS_PK_ECC:
          status = export_gnutls_pubkey_ecc( handle, &key->u.a.pubkey, &key->u.a.pubkey_len );
          break;
  
      case GNUTLS_PK_DSA:
          status = export_gnutls_pubkey_dsa( handle, key->u.a.bitlen, &key->u.a.pubkey, &key->u.a.pubkey_len );
          break;
  
      default:
          ERR( "unhandled algorithm %u\n", pk_alg );
          return STATUS_INTERNAL_ERROR;
      }
  
      if (status)
      {
          pgnutls_privkey_deinit( handle );
          return status;
      }
  
      key->u.a.handle = handle;
      return STATUS_SUCCESS;
  }
  
  NTSTATUS key_export_ecc( struct key *key, UCHAR *buf, ULONG len, ULONG *ret_len )
  {
      BCRYPT_ECCKEY_BLOB *ecc_blob;
      gnutls_ecc_curve_t curve;
      gnutls_datum_t x, y, d;
      DWORD magic, size;
      UCHAR *src, *dst;
      int ret;
  
      if ((ret = pgnutls_privkey_export_ecc_raw( key->u.a.handle, &curve, &x, &y, &d )))
      {
          pgnutls_perror( ret );
          return STATUS_INTERNAL_ERROR;
      }
  
      switch (curve)
      {
      case GNUTLS_ECC_CURVE_SECP256R1:
          magic = BCRYPT_ECDH_PRIVATE_P256_MAGIC;
          size = 32;
          break;
  
      default:
          FIXME( "curve %u not supported\n", curve );
          free( x.data ); free( y.data ); free( d.data );
          return STATUS_NOT_IMPLEMENTED;
      }
  
      *ret_len = sizeof(*ecc_blob) + size * 3;
      if (len >= *ret_len && buf)
      {
          ecc_blob = (BCRYPT_ECCKEY_BLOB *)buf;
          ecc_blob->dwMagic = magic;
          ecc_blob->cbKey   = size;
  
          dst = (UCHAR *)(ecc_blob + 1);
          if (x.size == size + 1) src = x.data + 1;
          else src = x.data;
          memcpy( dst, src, size );
  
          dst += size;
          if (y.size == size + 1) src = y.data + 1;
          else src = y.data;
          memcpy( dst, src, size );
  
          dst += size;
          if (d.size == size + 1) src = d.data + 1;
          else src = d.data;
          memcpy( dst, src, size );
      }
  
      free( x.data ); free( y.data ); free( d.data );
      return STATUS_SUCCESS;
  }
  
  NTSTATUS key_import_ecc( struct key *key, UCHAR *buf, ULONG len )
  {
      BCRYPT_ECCKEY_BLOB *ecc_blob;
      gnutls_ecc_curve_t curve;
      gnutls_privkey_t handle;
      gnutls_datum_t x, y, k;
      NTSTATUS status;
      int ret;
  
      switch (key->alg_id)
      {
      case ALG_ID_ECDH_P256:
      case ALG_ID_ECDSA_P256:
          curve = GNUTLS_ECC_CURVE_SECP256R1;
          break;
  
      default:
          FIXME( "algorithm %u not yet supported\n", key->alg_id );
          return STATUS_NOT_IMPLEMENTED;
      }
  
      if ((ret = pgnutls_privkey_init( &handle )))
      {
          pgnutls_perror( ret );
          return STATUS_INTERNAL_ERROR;
      }
  
      ecc_blob = (BCRYPT_ECCKEY_BLOB *)buf;
      x.data = (unsigned char *)(ecc_blob + 1);
      x.size = ecc_blob->cbKey;
      y.data = x.data + ecc_blob->cbKey;
      y.size = ecc_blob->cbKey;
      k.data = y.data + ecc_blob->cbKey;
      k.size = ecc_blob->cbKey;
  
      if ((ret = pgnutls_privkey_import_ecc_raw( handle, curve, &x, &y, &k )))
      {
          pgnutls_perror( ret );
          pgnutls_privkey_deinit( handle );
          return STATUS_INTERNAL_ERROR;
      }
  
      if ((status = export_gnutls_pubkey_ecc( handle, &key->u.a.pubkey, &key->u.a.pubkey_len )))
      {
          pgnutls_privkey_deinit( handle );
          return status;
      }
  
      key->u.a.handle = handle;
      return STATUS_SUCCESS;
  }
  
  NTSTATUS key_export_dsa_capi( struct key *key, UCHAR *buf, ULONG len, ULONG *ret_len )
  {
      BLOBHEADER *hdr;
      DSSPUBKEY *pubkey;
      gnutls_datum_t p, q, g, y, x;
      UCHAR *src, *dst;
      int ret, size;
  
      if ((ret = pgnutls_privkey_export_dsa_raw( key->u.a.handle, &p, &q, &g, &y, &x )))
      {
          pgnutls_perror( ret );
          return STATUS_INTERNAL_ERROR;
      }
  
      if ((q.size != 20 && q.size != 21) || (x.size != 20 && x.size != 21))
      {
          ERR( "can't export key in this format\n" );
          free( p.data ); free( q.data ); free( g.data ); free( y.data ); free( x.data );
          return STATUS_NOT_SUPPORTED;
      }
  
      size = key->u.a.bitlen / 8;
      *ret_len = sizeof(*hdr) + sizeof(*pubkey) + size * 2 + 40 + sizeof(key->u.a.dss_seed);
      if (len >= *ret_len && buf)
      {
          hdr = (BLOBHEADER *)buf;
          hdr->bType    = PRIVATEKEYBLOB;
          hdr->bVersion = 2;
          hdr->reserved = 0;
          hdr->aiKeyAlg = CALG_DSS_SIGN;
  
          pubkey = (DSSPUBKEY *)(hdr + 1);
          pubkey->magic  = MAGIC_DSS2;
          pubkey->bitlen = key->u.a.bitlen;
  
          dst = (UCHAR *)(pubkey + 1);
          if (p.size == size + 1) src = p.data + 1;
          else src = p.data;
          memcpy( dst, src, size );
  
          dst += size;
          if (q.size == 21) src = q.data + 1;
          else src = q.data;
          memcpy( dst, src, 20 );
  
          dst += 20;
          if (g.size == size + 1) src = g.data + 1;
          else src = g.data;
          memcpy( dst, src, size );
  
          dst += size;
          if (x.size == 21) src = x.data + 1;
          else src = x.data;
          memcpy( dst, src, 20 );
  
          dst += 20;
          memcpy( dst, &key->u.a.dss_seed, sizeof(key->u.a.dss_seed) );
      }
  
      free( p.data ); free( q.data ); free( g.data ); free( y.data ); free( x.data );
      return STATUS_SUCCESS;
  }
  
  NTSTATUS key_import_dsa_capi( struct key *key, UCHAR *buf, ULONG len )
  {
      BLOBHEADER *hdr = (BLOBHEADER *)buf;
      DSSPUBKEY *pubkey;
      gnutls_privkey_t handle;
      gnutls_datum_t p, q, g, y, x;
      unsigned char dummy[128];
      int ret, size;
  
      if ((ret = pgnutls_privkey_init( &handle )))
      {
          pgnutls_perror( ret );
          return STATUS_INTERNAL_ERROR;
      }
  
      hdr = (BLOBHEADER *)buf;
      pubkey = (DSSPUBKEY *)(hdr + 1);
      size = pubkey->bitlen / 8;
  
      p.data = (unsigned char *)(pubkey + 1);
      p.size = size;
      q.data = p.data + size;
      q.size = 20;
      g.data = q.data + 20;
      g.size = size;
      x.data = g.data + size;
      x.size = 20;
  
      WARN( "using dummy public key\n" );
      memset( dummy, 1, sizeof(dummy) );
      y.data = dummy;
      y.size = min( p.size, sizeof(dummy) );
  
      if ((ret = pgnutls_privkey_import_dsa_raw( handle, &p, &q, &g, &y, &x )))
      {
          pgnutls_perror( ret );
          pgnutls_privkey_deinit( handle );
          return STATUS_INTERNAL_ERROR;
      }
  
      memcpy( &key->u.a.dss_seed, x.data + x.size, sizeof(key->u.a.dss_seed) );
  
      key->u.a.handle = handle;
      return STATUS_SUCCESS;
  }
  
  NTSTATUS key_asymmetric_init( struct key *key, struct algorithm *alg, ULONG bitlen, const UCHAR *pubkey,
                                ULONG pubkey_len )
  {
      if (!libgnutls_handle) return STATUS_INTERNAL_ERROR;
  
      switch (alg->id)
      {
      case ALG_ID_ECDH_P256:
      case ALG_ID_ECDSA_P256:
      case ALG_ID_ECDSA_P384:
      case ALG_ID_RSA:
      case ALG_ID_RSA_SIGN:
      case ALG_ID_DSA:
          break;
  
      default:
          FIXME( "algorithm %u not supported\n", alg->id );
          return STATUS_NOT_SUPPORTED;
      }
  
      if (pubkey_len)
      {
          if (!(key->u.a.pubkey = heap_alloc( pubkey_len ))) return STATUS_NO_MEMORY;
          memcpy( key->u.a.pubkey, pubkey, pubkey_len );
          key->u.a.pubkey_len = pubkey_len;
      }
      key->alg_id     = alg->id;
      key->u.a.bitlen = bitlen;
  
      return STATUS_SUCCESS;
  }
  
  static NTSTATUS import_gnutls_pubkey_ecc( struct key *key, gnutls_pubkey_t *gnutls_key )
  {
      BCRYPT_ECCKEY_BLOB *ecc_blob;
      gnutls_ecc_curve_t curve;
      gnutls_datum_t x, y;
      int ret;
  
      switch (key->alg_id)
      {
      case ALG_ID_ECDSA_P256: curve = GNUTLS_ECC_CURVE_SECP256R1; break;
      case ALG_ID_ECDSA_P384: curve = GNUTLS_ECC_CURVE_SECP384R1; break;
  
      default:
          FIXME( "algorithm %u not yet supported\n", key->alg_id );
          return STATUS_NOT_IMPLEMENTED;
      }
  
      if ((ret = pgnutls_pubkey_init( gnutls_key )))
      {
          pgnutls_perror( ret );
          return STATUS_INTERNAL_ERROR;
      }
  
      ecc_blob = (BCRYPT_ECCKEY_BLOB *)key->u.a.pubkey;
      x.data = key->u.a.pubkey + sizeof(*ecc_blob);
      x.size = ecc_blob->cbKey;
      y.data = key->u.a.pubkey + sizeof(*ecc_blob) + ecc_blob->cbKey;
      y.size = ecc_blob->cbKey;
  
      if ((ret = pgnutls_pubkey_import_ecc_raw( *gnutls_key, curve, &x, &y )))
      {
          pgnutls_perror( ret );
          pgnutls_pubkey_deinit( *gnutls_key );
          return STATUS_INTERNAL_ERROR;
      }
  
      return STATUS_SUCCESS;
  }
  
  static NTSTATUS import_gnutls_pubkey_rsa( struct key *key, gnutls_pubkey_t *gnutls_key )
  {
      BCRYPT_RSAKEY_BLOB *rsa_blob;
      gnutls_datum_t m, e;
      int ret;
  
      if ((ret = pgnutls_pubkey_init( gnutls_key )))
      {
          pgnutls_perror( ret );
          return STATUS_INTERNAL_ERROR;
      }
  
      rsa_blob = (BCRYPT_RSAKEY_BLOB *)key->u.a.pubkey;
      e.data = key->u.a.pubkey + sizeof(*rsa_blob);
      e.size = rsa_blob->cbPublicExp;
      m.data = key->u.a.pubkey + sizeof(*rsa_blob) + rsa_blob->cbPublicExp;
      m.size = rsa_blob->cbModulus;
  
      if ((ret = pgnutls_pubkey_import_rsa_raw( *gnutls_key, &m, &e )))
      {
          pgnutls_perror( ret );
          pgnutls_pubkey_deinit( *gnutls_key );
          return STATUS_INTERNAL_ERROR;
      }
  
      return STATUS_SUCCESS;
  }
  
  static NTSTATUS import_gnutls_pubkey_dsa( struct key *key, gnutls_pubkey_t *gnutls_key )
  {
      BCRYPT_DSA_KEY_BLOB *dsa_blob;
      gnutls_datum_t p, q, g, y;
      int ret;
  
      if ((ret = pgnutls_pubkey_init( gnutls_key )))
      {
          pgnutls_perror( ret );
          return STATUS_INTERNAL_ERROR;
      }
  
      dsa_blob = (BCRYPT_DSA_KEY_BLOB *)key->u.a.pubkey;
      p.data = key->u.a.pubkey + sizeof(*dsa_blob);
      p.size = dsa_blob->cbKey;
      q.data = dsa_blob->q;
      q.size = sizeof(dsa_blob->q);
      g.data = key->u.a.pubkey + sizeof(*dsa_blob) + dsa_blob->cbKey;
      g.size = dsa_blob->cbKey;
      y.data = key->u.a.pubkey + sizeof(*dsa_blob) + dsa_blob->cbKey * 2;
      y.size = dsa_blob->cbKey;
  
      if ((ret = pgnutls_pubkey_import_dsa_raw( *gnutls_key, &p, &q, &g, &y )))
      {
          pgnutls_perror( ret );
          pgnutls_pubkey_deinit( *gnutls_key );
          return STATUS_INTERNAL_ERROR;
      }
  
      return STATUS_SUCCESS;
  }
  
  static NTSTATUS import_gnutls_pubkey( struct key *key, gnutls_pubkey_t *gnutls_key )
  {
      switch (key->alg_id)
      {
      case ALG_ID_ECDSA_P256:
      case ALG_ID_ECDSA_P384:
          return import_gnutls_pubkey_ecc( key, gnutls_key );
  
      case ALG_ID_RSA:
      case ALG_ID_RSA_SIGN:
          return import_gnutls_pubkey_rsa( key, gnutls_key );
  
      case ALG_ID_DSA:
          return import_gnutls_pubkey_dsa( key, gnutls_key );
  
      default:
          FIXME("algorithm %u not yet supported\n", key->alg_id );
          return STATUS_NOT_IMPLEMENTED;
      }
  }
  
  static NTSTATUS prepare_gnutls_signature_dsa( struct key *key, UCHAR *signature, ULONG signature_len,
                                                gnutls_datum_t *gnutls_signature )
  {
      struct buffer buffer;
      DWORD r_len = signature_len / 2;
      DWORD s_len = r_len;
      BYTE *r = signature;
      BYTE *s = signature + r_len;
  
      buffer_init( &buffer );
      buffer_append_asn1_r_s( &buffer, r, r_len, s, s_len );
      if (buffer.error)
      {
          buffer_free( &buffer );
          return STATUS_NO_MEMORY;
      }
  
      gnutls_signature->data = buffer.buffer;
      gnutls_signature->size = buffer.pos;
      return STATUS_SUCCESS;
  }
  
  static NTSTATUS prepare_gnutls_signature_rsa( struct key *key, UCHAR *signature, ULONG signature_len,
                                                gnutls_datum_t *gnutls_signature )
  {
      gnutls_signature->data = signature;
      gnutls_signature->size = signature_len;
      return STATUS_SUCCESS;
  }
  
  static NTSTATUS prepare_gnutls_signature( struct key *key, UCHAR *signature, ULONG signature_len,
                                            gnutls_datum_t *gnutls_signature )
  {
      switch (key->alg_id)
      {
      case ALG_ID_ECDSA_P256:
      case ALG_ID_ECDSA_P384:
      case ALG_ID_DSA:
          return prepare_gnutls_signature_dsa( key, signature, signature_len, gnutls_signature );
  
      case ALG_ID_RSA:
      case ALG_ID_RSA_SIGN:
          return prepare_gnutls_signature_rsa( key, signature, signature_len, gnutls_signature );
  
      default:
          FIXME( "algorithm %u not yet supported\n", key->alg_id );
          return STATUS_NOT_IMPLEMENTED;
      }
  }
  
  static gnutls_digest_algorithm_t get_digest_from_id( const WCHAR *alg_id )
  {
      if (!strcmpW( alg_id, BCRYPT_SHA1_ALGORITHM ))   return GNUTLS_DIG_SHA1;
      if (!strcmpW( alg_id, BCRYPT_SHA256_ALGORITHM )) return GNUTLS_DIG_SHA256;
      if (!strcmpW( alg_id, BCRYPT_SHA384_ALGORITHM )) return GNUTLS_DIG_SHA384;
      if (!strcmpW( alg_id, BCRYPT_SHA512_ALGORITHM )) return GNUTLS_DIG_SHA512;
      if (!strcmpW( alg_id, BCRYPT_MD2_ALGORITHM ))    return GNUTLS_DIG_MD2;
      if (!strcmpW( alg_id, BCRYPT_MD5_ALGORITHM ))    return GNUTLS_DIG_MD5;
      return -1;
  }
  
  NTSTATUS key_asymmetric_verify( struct key *key, void *padding, UCHAR *hash, ULONG hash_len, UCHAR *signature,
                                  ULONG signature_len, DWORD flags )
  {
      gnutls_digest_algorithm_t hash_alg;
      gnutls_sign_algorithm_t sign_alg;
      gnutls_datum_t gnutls_hash, gnutls_signature;
      gnutls_pk_algorithm_t pk_alg;
      gnutls_pubkey_t gnutls_key;
      NTSTATUS status;
      int ret;
  
      switch (key->alg_id)
      {
      case ALG_ID_ECDSA_P256:
      case ALG_ID_ECDSA_P384:
      {
          if (flags) FIXME( "flags %08x not supported\n", flags );
  
          /* only the hash size must match, not the actual hash function */
          switch (hash_len)
          {
          case 20: hash_alg = GNUTLS_DIG_SHA1; break;
          case 32: hash_alg = GNUTLS_DIG_SHA256; break;
          case 48: hash_alg = GNUTLS_DIG_SHA384; break;
  
          default:
              FIXME( "hash size %u not yet supported\n", hash_len );
              return STATUS_INVALID_SIGNATURE;
          }
          pk_alg = GNUTLS_PK_ECC;
          break;
      }
      case ALG_ID_RSA:
      case ALG_ID_RSA_SIGN:
      {
          BCRYPT_PKCS1_PADDING_INFO *info = (BCRYPT_PKCS1_PADDING_INFO *)padding;
  
          if (!(flags & BCRYPT_PAD_PKCS1) || !info) return STATUS_INVALID_PARAMETER;
          if (!info->pszAlgId) return STATUS_INVALID_SIGNATURE;
  
          if ((hash_alg = get_digest_from_id(info->pszAlgId)) == -1)
          {
              FIXME( "hash algorithm %s not supported\n", debugstr_w(info->pszAlgId) );
              return STATUS_NOT_SUPPORTED;
          }
          pk_alg = GNUTLS_PK_RSA;
          break;
      }
      case ALG_ID_DSA:
      {
          if (flags) FIXME( "flags %08x not supported\n", flags );
          if (hash_len != 20)
          {
              FIXME( "hash size %u not supported\n", hash_len );
              return STATUS_INVALID_PARAMETER;
          }
          hash_alg = GNUTLS_DIG_SHA1;
          pk_alg = GNUTLS_PK_DSA;
          break;
      }
      default:
          FIXME( "algorithm %u not yet supported\n", key->alg_id );
          return STATUS_NOT_IMPLEMENTED;
      }
  
      if ((sign_alg = pgnutls_pk_to_sign( pk_alg, hash_alg )) == GNUTLS_SIGN_UNKNOWN)
      {
          FIXME("GnuTLS does not support algorithm %u with hash len %u\n", key->alg_id, hash_len );
          return STATUS_NOT_IMPLEMENTED;
      }
  
      if ((status = import_gnutls_pubkey( key, &gnutls_key ))) return status;
      if ((status = prepare_gnutls_signature( key, signature, signature_len, &gnutls_signature )))
      {
          pgnutls_pubkey_deinit( gnutls_key );
          return status;
      }
  
      gnutls_hash.data = hash;
      gnutls_hash.size = hash_len;
      ret = pgnutls_pubkey_verify_hash2( gnutls_key, sign_alg, 0, &gnutls_hash, &gnutls_signature );
  
      if (gnutls_signature.data != signature) heap_free( gnutls_signature.data );
      pgnutls_pubkey_deinit( gnutls_key );
      return (ret < 0) ? STATUS_INVALID_SIGNATURE : STATUS_SUCCESS;
  }
  
  static unsigned int get_signature_length( enum alg_id id )
  {
      switch (id)
      {
      case ALG_ID_ECDSA_P256: return 64;
      case ALG_ID_ECDSA_P384: return 96;
      case ALG_ID_DSA:        return 40;
      default:
          FIXME( "unhandled algorithm %u\n", id );
          return 0;
      }
  }
  
  static NTSTATUS format_gnutls_signature( enum alg_id type, gnutls_datum_t signature,
                                           UCHAR *output, ULONG output_len, ULONG *ret_len )
  {
      switch (type)
      {
      case ALG_ID_RSA:
      case ALG_ID_RSA_SIGN:
      {
          if (output_len < signature.size) return STATUS_BUFFER_TOO_SMALL;
          memcpy( output, signature.data, signature.size );
          *ret_len = signature.size;
          return STATUS_SUCCESS;
      }
      case ALG_ID_ECDSA_P256:
      case ALG_ID_ECDSA_P384:
      case ALG_ID_DSA:
      {
          int err;
          unsigned int pad_size_r, pad_size_s, sig_len = get_signature_length( type );
          gnutls_datum_t r, s; /* format as r||s */
          unsigned char *r_data, *s_data;
  
          if ((err = pgnutls_decode_rs_value( &signature, &r, &s )))
          {
              pgnutls_perror( err );
              return STATUS_INTERNAL_ERROR;
          }
  
          if (output_len < sig_len) return STATUS_BUFFER_TOO_SMALL;
  
          if (r.size % 2) /* remove prepended zero byte */
          {
              r.size--;
              r_data = r.data + 1;
          }
          else r_data = r.data;
  
          if (s.size % 2)
          {
              s.size--;
              s_data = s.data + 1;
          }
          else s_data = s.data;
  
          if (r.size + s.size > sig_len)
          {
              ERR( "we didn't get a correct signature\n" );
              return STATUS_INTERNAL_ERROR;
          }
  
          pad_size_r = (sig_len / 2) - r.size;
          pad_size_s = (sig_len / 2) - s.size;
          memset( output, 0, sig_len );
  
          memcpy( output + pad_size_r, r_data, r.size );
          memcpy( output + (sig_len / 2) + pad_size_s, s_data, s.size );
  
          *ret_len = sig_len;
          free( r.data ); free( s.data );
          return STATUS_SUCCESS;
      }
      default:
          return STATUS_INTERNAL_ERROR;
      }
  }
  
  NTSTATUS key_asymmetric_sign( struct key *key, void *padding, UCHAR *input, ULONG input_len, UCHAR *output,
                                ULONG output_len, ULONG *ret_len, ULONG flags )
  {
      BCRYPT_PKCS1_PADDING_INFO *pad = padding;
      gnutls_datum_t hash, signature;
      gnutls_digest_algorithm_t hash_alg;
      NTSTATUS status;
      int ret;
  
      if (key->alg_id == ALG_ID_ECDSA_P256 || key->alg_id == ALG_ID_ECDSA_P384)
      {
          /* With ECDSA, we find the digest algorithm from the hash length, and verify it */
          switch (input_len)
          {
          case 20: hash_alg = GNUTLS_DIG_SHA1; break;
          case 32: hash_alg = GNUTLS_DIG_SHA256; break;
          case 48: hash_alg = GNUTLS_DIG_SHA384; break;
          case 64: hash_alg = GNUTLS_DIG_SHA512; break;
  
          default:
              FIXME( "hash size %u not yet supported\n", input_len );
              return STATUS_INVALID_PARAMETER;
          }
  
          if (flags == BCRYPT_PAD_PKCS1 && pad && pad->pszAlgId && get_digest_from_id( pad->pszAlgId ) != hash_alg)
          {
              WARN( "incorrect hashing algorithm %s, expected %u\n", debugstr_w(pad->pszAlgId), hash_alg );
              return STATUS_INVALID_PARAMETER;
          }
      }
      else if (key->alg_id == ALG_ID_DSA)
      {
          if (flags) FIXME( "flags %08x not supported\n", flags );
          if (input_len != 20)
          {
              FIXME( "hash size %u not supported\n", input_len );
              return STATUS_INVALID_PARAMETER;
          }
          hash_alg = GNUTLS_DIG_SHA1;
      }
      else if (flags == BCRYPT_PAD_PKCS1)
      {
          if (!pad || !pad->pszAlgId)
          {
              WARN( "padding info not found\n" );
              return STATUS_INVALID_PARAMETER;
          }
  
          if ((hash_alg = get_digest_from_id( pad->pszAlgId )) == -1)
          {
              FIXME( "hash algorithm %s not recognized\n", debugstr_w(pad->pszAlgId) );
              return STATUS_NOT_SUPPORTED;
          }
      }
      else if (!flags)
      {
           WARN( "invalid flags %08x\n", flags );
           return STATUS_INVALID_PARAMETER;
      }
      else
      {
          FIXME( "flags %08x not implemented\n", flags );
          return STATUS_NOT_IMPLEMENTED;
      }
  
      if (!input)
      {
          *ret_len = key->u.a.bitlen / 8;
          return STATUS_SUCCESS;
      }
      if (!key->u.a.handle) return STATUS_INVALID_PARAMETER;
  
      hash.data = input;
      hash.size = input_len;
  
      signature.data = NULL;
      signature.size = 0;
  
      if ((ret = pgnutls_privkey_sign_hash( key->u.a.handle, hash_alg, 0, &hash, &signature )))
      {
          pgnutls_perror( ret );
          return STATUS_INTERNAL_ERROR;
      }
  
      status = format_gnutls_signature( key->alg_id, signature, output, output_len, ret_len );
  
      free( signature.data );
      return status;
  }
  
  NTSTATUS key_destroy( struct key *key )
  {
      if (key_is_symmetric( key ))
      {
          if (key->u.s.handle) pgnutls_cipher_deinit( key->u.s.handle );
          heap_free( key->u.s.vector );
          heap_free( key->u.s.secret );
      }
      else
      {
          if (key->u.a.handle) pgnutls_privkey_deinit( key->u.a.handle );
          heap_free( key->u.a.pubkey );
      }
      heap_free( key );
      return STATUS_SUCCESS;
  }
  #endif
  