chacha20poly1305.h

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/*
 * SPDX-FileCopyrightText: 2018 Koen Zandberg
 * SPDX-License-Identifier: LGPL-2.1-only
 */
 
#pragma once
 
#include "crypto/poly1305.h"
 
#ifdef __cplusplus
extern "C" {
#endif
 
#define CHACHA20POLY1305_CONSTANT_BYTES (16U)   
#define CHACHA20POLY1305_KEY_BYTES      (32U)   
#define CHACHA20POLY1305_COUNTER_BYTES  (4U)    
#define CHACHA20POLY1305_NONCE_BYTES    (12U)   
#define CHACHA20POLY1305_TAG_BYTES      (16U)   
#define CHACHA20POLY1305_BLOCK_BYTES    (64U)   
typedef union {
    uint32_t words[CHACHA20POLY1305_BLOCK_BYTES / sizeof(uint32_t)];
    struct {
        uint32_t constant[CHACHA20POLY1305_CONSTANT_BYTES / sizeof(uint32_t)];
        uint32_t key[CHACHA20POLY1305_KEY_BYTES / sizeof(uint32_t)];
        uint32_t counter[CHACHA20POLY1305_COUNTER_BYTES / sizeof(uint32_t)];
        uint32_t nonce[CHACHA20POLY1305_NONCE_BYTES / sizeof(uint32_t)];
    }__attribute__ ((__packed__)) split;    
} chacha20_ctx_t;
 
typedef union {
    /* We need both the state matrix and the poly1305 state, but nearly not at
     * the same time. This works as long as the first 8 members of state
     * overlap fully or completely not with the first and second key parts
     * from the @ref poly1305_ctx_t struct */
    chacha20_ctx_t chacha20;   
    poly1305_ctx_t poly;    
} chacha20poly1305_ctx_t;
 
void chacha20poly1305_encrypt(uint8_t *cipher, const uint8_t *msg,
                              size_t msglen, const uint8_t *aad, size_t aadlen,
                              const uint8_t *key, const uint8_t *nonce);
int chacha20poly1305_decrypt(const uint8_t *cipher, size_t cipherlen,
                             uint8_t *msg, size_t *msglen,
                             const uint8_t *aad, size_t aadlen,
                             const uint8_t *key, const uint8_t *nonce);
 
void chacha20_encrypt_decrypt(  const uint8_t *key,
                                const uint8_t *nonce,
                                uint32_t counter,
                                const uint8_t *input,
                                size_t input_length,
                                uint8_t *output);
void chacha20_setup(chacha20_ctx_t *ctx,
                    const uint8_t *key,
                    const uint8_t *nonce,
                    const uint32_t counter);
 
void chacha20_update(   chacha20_ctx_t *ctx,
                        const uint8_t *input,
                        uint8_t *output);
 
void chacha20_finish(   chacha20_ctx_t *ctx,
                        const uint8_t *input,
                        size_t input_length,
                        uint8_t *output);
 
#ifdef __cplusplus
}
#endif