// Monocypher version 4.0.0
//
// 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
//
#ifndef MONOCYPHER_H
#define MONOCYPHER_H
#include
#include
#ifdef MONOCYPHER_CPP_NAMESPACE
namespace MONOCYPHER_CPP_NAMESPACE {
#elif defined(__cplusplus)
extern "C" {
#endif
// 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
// --------------------
void crypto_wipe(void *secret, size_t size);
// Authenticated encryption
// ------------------------
void crypto_aead_lock(uint8_t *cipher_text,
uint8_t mac [16],
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_aead_unlock(uint8_t *plain_text,
const uint8_t mac [16],
const uint8_t key [32],
const uint8_t nonce[24],
const uint8_t *ad, size_t ad_size,
const uint8_t *cipher_text, size_t text_size);
// Authenticated stream
// --------------------
typedef struct {
uint64_t counter;
uint8_t key[32];
uint8_t nonce[8];
} crypto_aead_ctx;
void crypto_aead_init_x(crypto_aead_ctx *ctx,
const uint8_t key[32], const uint8_t nonce[24]);
void crypto_aead_init_djb(crypto_aead_ctx *ctx,
const uint8_t key[32], const uint8_t nonce[8]);
void crypto_aead_init_ietf(crypto_aead_ctx *ctx,
const uint8_t key[32], const uint8_t nonce[12]);
void crypto_aead_write(crypto_aead_ctx *ctx,
uint8_t *cipher_text,
uint8_t mac[16],
const uint8_t *ad , size_t ad_size,
const uint8_t *plain_text, size_t text_size);
int crypto_aead_read(crypto_aead_ctx *ctx,
uint8_t *plain_text,
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, size_t hash_size,
const uint8_t *message, size_t message_size);
void crypto_blake2b_keyed(uint8_t *hash, size_t hash_size,
const uint8_t *key, size_t key_size,
const uint8_t *message, size_t message_size);
// Incremental interface
typedef struct {
// Do not rely on the size or contents of this type,
// for they may change without notice.
uint64_t hash[8];
uint64_t input_offset[2];
uint64_t input[16];
size_t input_idx;
size_t hash_size;
} crypto_blake2b_ctx;
void crypto_blake2b_init(crypto_blake2b_ctx *ctx, size_t hash_size);
void crypto_blake2b_keyed_init(crypto_blake2b_ctx *ctx, size_t hash_size,
const uint8_t *key, size_t key_size);
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);
// Password key derivation (Argon2)
// --------------------------------
#define CRYPTO_ARGON2_D 0
#define CRYPTO_ARGON2_I 1
#define CRYPTO_ARGON2_ID 2
typedef struct {
uint32_t algorithm; // Argon2d, Argon2i, Argon2id
uint32_t nb_blocks; // memory hardness, >= 8 * nb_lanes
uint32_t nb_passes; // CPU hardness, >= 1 (>= 3 recommended for Argon2i)
uint32_t nb_lanes; // parallelism level (single threaded anyway)
} crypto_argon2_config;
typedef struct {
const uint8_t *pass;
const uint8_t *salt;
uint32_t pass_size;
uint32_t salt_size; // 16 bytes recommended
} crypto_argon2_inputs;
typedef struct {
const uint8_t *key; // may be NULL if no key
const uint8_t *ad; // may be NULL if no additional data
uint32_t key_size; // 0 if no key (32 bytes recommended otherwise)
uint32_t ad_size; // 0 if no additional data
} crypto_argon2_extras;
extern const crypto_argon2_extras crypto_argon2_no_extras;
void crypto_argon2(uint8_t *hash, uint32_t hash_size, void *work_area,
crypto_argon2_config config,
crypto_argon2_inputs inputs,
crypto_argon2_extras extras);
// Key exchange (X-25519)
// ----------------------
// Shared secrets are not quite random.
// Hash them to derive an actual shared key.
void crypto_x25519_public_key(uint8_t public_key[32],
const uint8_t secret_key[32]);
void crypto_x25519(uint8_t raw_shared_secret[32],
const uint8_t your_secret_key [32],
const uint8_t their_public_key [32]);
// Conversion to EdDSA
void crypto_x25519_to_eddsa(uint8_t eddsa[32], const uint8_t x25519[32]);
// scalar "division"
// Used for OPRF. Be aware that exponential blinding is less secure
// than Diffie-Hellman key exchange.
void crypto_x25519_inverse(uint8_t blind_salt [32],
const uint8_t private_key[32],
const uint8_t curve_point[32]);
// "Dirty" versions of x25519_public_key().
// Use with crypto_elligator_rev().
// Leaks 3 bits of the private key.
void crypto_x25519_dirty_small(uint8_t pk[32], const uint8_t sk[32]);
void crypto_x25519_dirty_fast (uint8_t pk[32], const uint8_t sk[32]);
// Signatures
// ----------
// EdDSA with curve25519 + BLAKE2b
void crypto_eddsa_key_pair(uint8_t secret_key[64],
uint8_t public_key[32],
uint8_t seed[32]);
void crypto_eddsa_sign(uint8_t signature [64],
const uint8_t secret_key[64],
const uint8_t *message, size_t message_size);
int crypto_eddsa_check(const uint8_t signature [64],
const uint8_t public_key[32],
const uint8_t *message, size_t message_size);
// Conversion to X25519
void crypto_eddsa_to_x25519(uint8_t x25519[32], const uint8_t eddsa[32]);
// EdDSA building blocks
void crypto_eddsa_trim_scalar(uint8_t out[32], const uint8_t in[32]);
void crypto_eddsa_reduce(uint8_t reduced[32], const uint8_t expanded[64]);
void crypto_eddsa_mul_add(uint8_t r[32],
const uint8_t a[32],
const uint8_t b[32],
const uint8_t c[32]);
void crypto_eddsa_scalarbase(uint8_t point[32], const uint8_t scalar[32]);
int crypto_eddsa_check_equation(const uint8_t signature[64],
const uint8_t public_key[32],
const uint8_t h_ram[32]);
// Chacha20
// --------
// Specialised hash.
// Used to hash X25519 shared secrets.
void crypto_chacha20_h(uint8_t out[32],
const uint8_t key[32],
const uint8_t in [16]);
// Unauthenticated stream cipher.
// Don't forget to add authentication.
uint64_t crypto_chacha20_djb(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);
uint32_t crypto_chacha20_ietf(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);
uint64_t crypto_chacha20_x(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);
// Poly 1305
// ---------
// This is a *one time* authenticator.
// Disclosing the mac reveals the key.
// See crypto_lock() on how to use it properly.
// Direct interface
void crypto_poly1305(uint8_t mac[16],
const uint8_t *message, size_t message_size,
const uint8_t key[32]);
// Incremental interface
typedef struct {
// Do not rely on the size or contents of this type,
// for they may change without notice.
uint8_t c[16]; // chunk of the message
size_t c_idx; // How many bytes are there in the chunk.
uint32_t r [4]; // constant multiplier (from the secret key)
uint32_t pad[4]; // random number added at the end (from the secret key)
uint32_t h [5]; // accumulated hash
} crypto_poly1305_ctx;
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]);
// Elligator 2
// -----------
// Elligator mappings proper
void crypto_elligator_map(uint8_t curve [32], const uint8_t hidden[32]);
int crypto_elligator_rev(uint8_t hidden[32], const uint8_t curve [32],
uint8_t tweak);
// Easy to use key pair generation
void crypto_elligator_key_pair(uint8_t hidden[32], uint8_t secret_key[32],
uint8_t seed[32]);
#ifdef __cplusplus
}
#endif
#endif // MONOCYPHER_H