/*
 * ProFTPD - mod_proxy SSH cipher API
 * Copyright (c) 2021-2022 TJ Saunders
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA.
 *
 * As a special exemption, TJ Saunders and other respective copyright holders
 * give permission to link this program with OpenSSL, and distribute the
 * resulting executable, without including the source code for OpenSSL in the
 * source distribution.
 */

#ifndef MOD_PROXY_SSH_CIPHER_H
#define MOD_PROXY_SSH_CIPHER_H

#include "mod_proxy.h"

#if defined(PR_USE_OPENSSL)

int proxy_ssh_cipher_init(void);
int proxy_ssh_cipher_free(void);

/* Returns the cipher block size, or 8, whichever is larger. This value is
 * used when reading in the first bytes of a packet in order to determine
 * the packet length.  See RFC4253, Section 6, "Binary Packet Protocol".
 */
size_t proxy_ssh_cipher_get_read_block_size(void);
size_t proxy_ssh_cipher_get_write_block_size(void);
void proxy_ssh_cipher_set_read_block_size(size_t);
void proxy_ssh_cipher_set_write_block_size(size_t);

/* Returns the cipher authenticated data size, or zero. */
size_t proxy_ssh_cipher_get_read_auth_size(void);
size_t proxy_ssh_cipher_get_read_auth_size2(void);
size_t proxy_ssh_cipher_get_write_auth_size(void);
size_t proxy_ssh_cipher_get_write_auth_size2(void);

const char *proxy_ssh_cipher_get_read_algo(void);
int proxy_ssh_cipher_set_read_algo(pool *p, const char *algo);
int proxy_ssh_cipher_set_read_key(pool *p, const EVP_MD *md,
  const unsigned char *k, uint32_t klen, const char *h, uint32_t hlen,
  int role);
int proxy_ssh_cipher_read_data(struct proxy_ssh_packet *pkt,
  unsigned char *data, uint32_t data_len, unsigned char **buf,
  uint32_t *buflen);

const char *proxy_ssh_cipher_get_write_algo(void);
int proxy_ssh_cipher_set_write_algo(pool *p, const char *algo);
int proxy_ssh_cipher_set_write_key(pool *p, const EVP_MD *md,
  const unsigned char *k, uint32_t klen, const char *h, uint32_t hlen,
  int role);
int proxy_ssh_cipher_write_data(struct proxy_ssh_packet *pkt,
  unsigned char *buf, size_t *bufsz);
#endif /* PR_USE_OPENSSL */

#endif /* MOD_PROXY_SSH_CIPHER_H */
