/*

 * This file is part of the SSH Library

 *

 * Copyright (c) 2014 by Aris Adamantiadis

 *

 * 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 Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

#ifndef ED25519_H_

#define ED25519_H_

#include "libssh/priv.h"

/**

 * @defgroup ed25519 ed25519 API

 * @internal

 * @brief API for DJB's ed25519

 *

 * @{ */

#define ED25519_PK_LEN 32

#define ED25519_SK_LEN 64

#define ED25519_SIG_LEN 64

typedef uint8_t ed25519_pubkey[ED25519_PK_LEN];

typedef uint8_t ed25519_privkey[ED25519_SK_LEN];

typedef uint8_t ed25519_signature[ED25519_SIG_LEN];

/** @internal

 * @brief generate an ed25519 key pair

 * @param[out] pk generated public key

 * @param[out] sk generated secret key

 * @return     0 on success, -1 on error.

 * */

int crypto_sign_ed25519_keypair(ed25519_pubkey pk, ed25519_privkey sk);

/** @internal

 * @brief sign a message with ed25519

 * @param[out] sm location to store the signed message.

 *                Its length should be mlen + 64.

 * @param[out] smlen pointer to the size of the signed message

 * @param[in] m message to be signed

 * @param[in] mlen length of the message to be signed

 * @param[in] sk secret key to sign the message with

 * @return    0 on success.

 */

int crypto_sign_ed25519(

    unsigned char *sm, uint64_t *smlen,

    const unsigned char *m, uint64_t mlen,

    const ed25519_privkey sk);

/** @internal

 * @brief "open" and verify the signature of a signed message

 * @param[out] m location to store the verified message.

 *               Its length should be equal to smlen.

 * @param[out] mlen pointer to the size of the verified message

 * @param[in] sm signed message to verify

 * @param[in] smlen length of the signed message to verify

 * @param[in] pk public key used to sign the message

 * @returns   0 on success (supposedly).

 */

int crypto_sign_ed25519_open(

    unsigned char *m, uint64_t *mlen,

    const unsigned char *sm, uint64_t smlen,

    const ed25519_pubkey pk);

/** @} */

#endif /* ED25519_H_ */