monocypher.h

// Monocypher version 3.1.1
//
// This file is dual-licensed.  Choose whichever licence you want from
// the two licences listed below.
//
// The first licence is a regular 2-clause BSD licence.  The second licence
// is the CC-0 from Creative Commons. It is intended to release Monocypher
// to the public domain.  The BSD licence serves as a fallback option.
//
// SPDX-License-Identifier: BSD-2-Clause OR CC0-1.0
//
// ------------------------------------------------------------------------
//
// Copyright (c) 2017-2019, Loup Vaillant
// All rights reserved.
//
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// 1. Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions and the following disclaimer in the
//    documentation and/or other materials provided with the
//    distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// ------------------------------------------------------------------------
//
// Written in 2017-2019 by Loup Vaillant
//
// To the extent possible under law, the author(s) have dedicated all copyright
// and related neighboring rights to this software to the public domain
// worldwide.  This software is distributed without any warranty.
//
// You should have received a copy of the CC0 Public Domain Dedication along
// with this software.  If not, see
// <https://creativecommons.org/publicdomain/zero/1.0/>

#ifndef MONOCYPHER_H
#define MONOCYPHER_H

#include <stddef.h>
#include <stdint.h>

#ifdef __cplusplus
extern "C" {
#endif

////////////////////////
/// Type definitions ///
////////////////////////

// Do not rely on the size or contents of any of the types below,
// they may change without notice.

// Poly1305
typedef struct {
    uint32_t r[4];   // constant multiplier (from the secret key)
    uint32_t h[5];   // accumulated hash
    uint32_t c[5];   // chunk of the message
    uint32_t pad[4]; // random number added at the end (from the secret key)
    size_t   c_idx;  // How many bytes are there in the chunk.
} crypto_poly1305_ctx;

// Hash (Blake2b)
typedef struct {
    uint64_t hash[8];
    uint64_t input_offset[2];
    uint64_t input[16];
    size_t   input_idx;
    size_t   hash_size;
} crypto_blake2b_ctx;


////////////////////////////
/// High level interface ///
////////////////////////////

// Constant time comparisons
// -------------------------

// Return 0 if a and b are equal, -1 otherwise
int crypto_verify16(const uint8_t a[16], const uint8_t b[16]);
int crypto_verify32(const uint8_t a[32], const uint8_t b[32]);
int crypto_verify64(const uint8_t a[64], const uint8_t b[64]);

// Erase sensitive data
// --------------------

// Please erase all copies
void crypto_wipe(void *secret, size_t size);


// Authenticated encryption
// ------------------------

// Direct interface
void crypto_lock(uint8_t        mac[16],
                 uint8_t       *cipher_text,
                 const uint8_t  key[32],
                 const uint8_t  nonce[24],
                 const uint8_t *plain_text, size_t text_size);
int crypto_unlock(uint8_t       *plain_text,
                  const uint8_t  key[32],
                  const uint8_t  nonce[24],
                  const uint8_t  mac[16],
                  const uint8_t *cipher_text, size_t text_size);

// Direct interface with additional data
void crypto_lock_aead(uint8_t        mac[16],
                      uint8_t       *cipher_text,
                      const uint8_t  key[32],
                      const uint8_t  nonce[24],
                      const uint8_t *ad        , size_t ad_size,
                      const uint8_t *plain_text, size_t text_size);
int crypto_unlock_aead(uint8_t       *plain_text,
                       const uint8_t  key[32],
                       const uint8_t  nonce[24],
                       const uint8_t  mac[16],
                       const uint8_t *ad         , size_t ad_size,
                       const uint8_t *cipher_text, size_t text_size);


// General purpose hash (Blake2b)
// ------------------------------

// Direct interface
void crypto_blake2b(uint8_t hash[64],
                    const uint8_t *message, size_t message_size);

void crypto_blake2b_general(uint8_t       *hash    , size_t hash_size,
                            const uint8_t *key     , size_t key_size, // optional
                            const uint8_t *message , size_t message_size);

// Incremental interface
void crypto_blake2b_init  (crypto_blake2b_ctx *ctx);
void crypto_blake2b_update(crypto_blake2b_ctx *ctx,
                           const uint8_t *message, size_t message_size);
void crypto_blake2b_final (crypto_blake2b_ctx *ctx, uint8_t *hash);

void crypto_blake2b_general_init(crypto_blake2b_ctx *ctx, size_t hash_size,
                                 const uint8_t      *key, size_t key_size);


////////////////////////////
/// Low level primitives ///
////////////////////////////

// For experts only.  You have been warned.

// Chacha20
// --------

// Specialised hash.
void crypto_hchacha20(uint8_t       out[32],
                      const uint8_t key[32],
                      const uint8_t in [16]);

void crypto_chacha20(uint8_t       *cipher_text,
                     const uint8_t *plain_text,
                     size_t         text_size,
                     const uint8_t  key[32],
                     const uint8_t  nonce[8]);
void crypto_xchacha20(uint8_t       *cipher_text,
                      const uint8_t *plain_text,
                      size_t         text_size,
                      const uint8_t  key[32],
                      const uint8_t  nonce[24]);
void crypto_ietf_chacha20(uint8_t       *cipher_text,
                          const uint8_t *plain_text,
                          size_t         text_size,
                          const uint8_t  key[32],
                          const uint8_t  nonce[12]);
uint64_t crypto_chacha20_ctr(uint8_t       *cipher_text,
                             const uint8_t *plain_text,
                             size_t         text_size,
                             const uint8_t  key[32],
                             const uint8_t  nonce[8],
                             uint64_t       ctr);
uint64_t crypto_xchacha20_ctr(uint8_t       *cipher_text,
                              const uint8_t *plain_text,
                              size_t         text_size,
                              const uint8_t  key[32],
                              const uint8_t  nonce[24],
                              uint64_t       ctr);
uint32_t crypto_ietf_chacha20_ctr(uint8_t       *cipher_text,
                                  const uint8_t *plain_text,
                                  size_t         text_size,
                                  const uint8_t  key[32],
                                  const uint8_t  nonce[12],
                                  uint32_t       ctr);

// Poly 1305
// ---------

// Direct interface
void crypto_poly1305(uint8_t        mac[16],
                     const uint8_t *message, size_t message_size,
                     const uint8_t  key[32]);

// Incremental interface
void crypto_poly1305_init  (crypto_poly1305_ctx *ctx, const uint8_t key[32]);
void crypto_poly1305_update(crypto_poly1305_ctx *ctx,
                            const uint8_t *message, size_t message_size);
void crypto_poly1305_final (crypto_poly1305_ctx *ctx, uint8_t mac[16]);



#ifdef __cplusplus
}
#endif

#endif // MONOCYPHER_H