/*

  silcpkcs1.h

  Author: Pekka Riikonen <priikone@silcnet.org>

  Copyright (C) 2003 Pekka Riikonen

  The contents of this file are subject to one of the Licenses specified 
  in the COPYING file;  You may not use this file except in compliance 
  with the License.

  The software distributed under the License is distributed on an "AS IS"
  basis, in the hope that it will be useful, but WITHOUT WARRANTY OF ANY
  KIND, either expressed or implied.  See the COPYING file for more
  information.

*/

/****h* silccrypt/SILC PKCS1 Interface
 *
 * DESCRIPTION
 *
 * This interface implements the PKCS#1 standard block encoding and decoding
 * routines.  It is used as part of RSA implementation to perform PKCS#1
 * RSA operations.  The routines encode and decode the data for RSA operations
 * such as digital signatures and their verification, and encryption and
 * decryption.
 *
 ***/

#ifndef SILCPKCS1_H
#define SILCPKCS1_H

/****d* silccrypt/SilcPKCS1API/SilcPkcs1BlockType
 *
 * NAME
 *
 *    typedef enum { ... } SilcPkcs1BlockType
 *
 * DESCRIPTION
 *
 *    Defines the PKCS#1 block types that define how the blcok is encoded
 *    for different RSA operations.
 *
 * SOURCE
 */
typedef enum {
  SILC_PKCS1_BT_PRV0 = 0x00,	/* Private key BT 0 */
  SILC_PKCS1_BT_PRV1 = 0x01,	/* Private key BT 1 (use this always) */
  SILC_PKCS1_BT_PUB  = 0x02,	/* Public key BT */
} SilcPkcs1BlockType;
/***/

/****f* silccrypt/SilcPKCS1API/silc_pkcs1_encode
 *
 * SYNOPSIS
 *
 *    bool silc_pkcs1_encode(SilcPkcs1BlockType bt,
 *                           const unsigned char *data,
 *                           SilcUInt32 data_len,
 *                           unsigned char *dest_data,
 *                           SilcUInt32 dest_data_size,
 *                           SilcRng rng);
 *
 * DESCRIPTION
 *
 *    Encodes PKCS#1 data block from the `data' according to the block type
 *    indicated by `bt'.  When encoding signatures the `bt' must be
 *    SILC_PKCS1_BT_PRV1 and when encoding encryption blocks the `bt' must
 *    be SILC_PKCS1_BT_PUB.  The encoded data is copied into the `dest_data'
 *    buffer which is size of `dest_data_size'.  If the `dest_data' is not
 *    able to hold the encoded block this returns FALSE.  Usually the
 *    `dest_data_size' is set to the RSA key length value as it is the
 *    length of one block.  The `rng' should be set when `bt' is set to
 *    SILC_PKCS1_BT_PUB.  If `rng' is NULL global RNG is used.  This
 *    function returns TRUE on success.
 *
 ***/
bool silc_pkcs1_encode(SilcPkcs1BlockType bt,
		       const unsigned char *data,
		       SilcUInt32 data_len,
		       unsigned char *dest_data,
		       SilcUInt32 dest_data_size,
		       SilcRng rng);

/****f* silccrypt/SilcPKCS1API/silc_pkcs1_decode
 *
 * SYNOPSIS
 *
 *    bool silc_pkcs1_decode(SilcPkcs1BlockType bt,
 *                           const unsigned char *data,
 *                           SilcUInt32 data_len,
 *                           unsigned char *dest_data,
 *                           SilcUInt32 dest_data_size,
 *                           SilcUInt32 *dest_len);
 *
 * DESCRIPTION
 *
 *    Decodes the PKCS#1 encoded block according to the block type `bt'.
 *    When verifying signatures the `bt' must be SILC_PKCS1_BT_PRV1 and
 *    when decrypting it must be SILC_PKCS1_BT_PUB.  This copies the
 *    decoded data into `dest_data' which is size of `dest_data_size'.  If
 *    the deocded block does not fit to `dest_data' this returns FALSE.
 *    Returns the decoded length into `dest_len'.
 *
 ***/
bool silc_pkcs1_decode(SilcPkcs1BlockType bt,
		       const unsigned char *data,
		       SilcUInt32 data_len,
		       unsigned char *dest_data,
		       SilcUInt32 dest_data_size,
		       SilcUInt32 *dest_len);

#endif /* SILCPKCS1_H */