| /** | |
| * \file chacha20.h | |
| * | |
| * \brief This file contains ChaCha20 definitions and functions. | |
| * | |
| * ChaCha20 is a stream cipher that can encrypt and decrypt | |
| * information. ChaCha was created by Daniel Bernstein as a variant of | |
| * its Salsa cipher https://cr.yp.to/chacha/chacha-20080128.pdf | |
| * ChaCha20 is the variant with 20 rounds, that was also standardized | |
| * in RFC 7539. | |
| * | |
| * \author Daniel King <damaki.gh@gmail.com> | |
| */ | |
| /* Copyright (C) 2006-2018, Arm Limited (or its affiliates), All Rights Reserved. | |
| * SPDX-License-Identifier: Apache-2.0 | |
| * | |
| * Licensed under the Apache License, Version 2.0 (the "License"); you may | |
| * not use this file except in compliance with the License. | |
| * You may obtain a copy of the License at | |
| * | |
| * http://www.apache.org/licenses/LICENSE-2.0 | |
| * | |
| * Unless required by applicable law or agreed to in writing, software | |
| * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT | |
| * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
| * See the License for the specific language governing permissions and | |
| * limitations under the License. | |
| * | |
| * This file is part of Mbed TLS (https://tls.mbed.org) | |
| */ | |
| #ifndef MBEDTLS_CHACHA20_H | |
| #define MBEDTLS_CHACHA20_H | |
| #if !defined(MBEDTLS_CONFIG_FILE) | |
| #include "config.h" | |
| #else | |
| #include MBEDTLS_CONFIG_FILE | |
| #endif | |
| #include <stdint.h> | |
| #include <stddef.h> | |
| #define MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA -0x0051 /**< Invalid input parameter(s). */ | |
| /* MBEDTLS_ERR_CHACHA20_FEATURE_UNAVAILABLE is deprecated and should not be | |
| * used. */ | |
| #define MBEDTLS_ERR_CHACHA20_FEATURE_UNAVAILABLE -0x0053 /**< Feature not available. For example, s part of the API is not implemented. */ | |
| /* MBEDTLS_ERR_CHACHA20_HW_ACCEL_FAILED is deprecated and should not be used. | |
| */ | |
| #define MBEDTLS_ERR_CHACHA20_HW_ACCEL_FAILED -0x0055 /**< Chacha20 hardware accelerator failed. */ | |
| #ifdef __cplusplus | |
| extern "C" { | |
| #endif | |
| #if !defined(MBEDTLS_CHACHA20_ALT) | |
| typedef struct mbedtls_chacha20_context | |
| { | |
| uint32_t state[16]; /*! The state (before round operations). */ | |
| uint8_t keystream8[64]; /*! Leftover keystream bytes. */ | |
| size_t keystream_bytes_used; /*! Number of keystream bytes already used. */ | |
| } | |
| mbedtls_chacha20_context; | |
| #else /* MBEDTLS_CHACHA20_ALT */ | |
| #include "chacha20_alt.h" | |
| #endif /* MBEDTLS_CHACHA20_ALT */ | |
| /** | |
| * \brief This function initializes the specified ChaCha20 context. | |
| * | |
| * It must be the first API called before using | |
| * the context. | |
| * | |
| * It is usually followed by calls to | |
| * \c mbedtls_chacha20_setkey() and | |
| * \c mbedtls_chacha20_starts(), then one or more calls to | |
| * to \c mbedtls_chacha20_update(), and finally to | |
| * \c mbedtls_chacha20_free(). | |
| * | |
| * \param ctx The ChaCha20 context to initialize. | |
| * This must not be \c NULL. | |
| */ | |
| void mbedtls_chacha20_init( mbedtls_chacha20_context *ctx ); | |
| /** | |
| * \brief This function releases and clears the specified | |
| * ChaCha20 context. | |
| * | |
| * \param ctx The ChaCha20 context to clear. This may be \c NULL, | |
| * in which case this function is a no-op. If it is not | |
| * \c NULL, it must point to an initialized context. | |
| * | |
| */ | |
| void mbedtls_chacha20_free( mbedtls_chacha20_context *ctx ); | |
| /** | |
| * \brief This function sets the encryption/decryption key. | |
| * | |
| * \note After using this function, you must also call | |
| * \c mbedtls_chacha20_starts() to set a nonce before you | |
| * start encrypting/decrypting data with | |
| * \c mbedtls_chacha_update(). | |
| * | |
| * \param ctx The ChaCha20 context to which the key should be bound. | |
| * It must be initialized. | |
| * \param key The encryption/decryption key. This must be \c 32 Bytes | |
| * in length. | |
| * | |
| * \return \c 0 on success. | |
| * \return #MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA if ctx or key is NULL. | |
| */ | |
| int mbedtls_chacha20_setkey( mbedtls_chacha20_context *ctx, | |
| const unsigned char key[32] ); | |
| /** | |
| * \brief This function sets the nonce and initial counter value. | |
| * | |
| * \note A ChaCha20 context can be re-used with the same key by | |
| * calling this function to change the nonce. | |
| * | |
| * \warning You must never use the same nonce twice with the same key. | |
| * This would void any confidentiality guarantees for the | |
| * messages encrypted with the same nonce and key. | |
| * | |
| * \param ctx The ChaCha20 context to which the nonce should be bound. | |
| * It must be initialized and bound to a key. | |
| * \param nonce The nonce. This must be \c 12 Bytes in size. | |
| * \param counter The initial counter value. This is usually \c 0. | |
| * | |
| * \return \c 0 on success. | |
| * \return #MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA if ctx or nonce is | |
| * NULL. | |
| */ | |
| int mbedtls_chacha20_starts( mbedtls_chacha20_context* ctx, | |
| const unsigned char nonce[12], | |
| uint32_t counter ); | |
| /** | |
| * \brief This function encrypts or decrypts data. | |
| * | |
| * Since ChaCha20 is a stream cipher, the same operation is | |
| * used for encrypting and decrypting data. | |
| * | |
| * \note The \p input and \p output pointers must either be equal or | |
| * point to non-overlapping buffers. | |
| * | |
| * \note \c mbedtls_chacha20_setkey() and | |
| * \c mbedtls_chacha20_starts() must be called at least once | |
| * to setup the context before this function can be called. | |
| * | |
| * \note This function can be called multiple times in a row in | |
| * order to encrypt of decrypt data piecewise with the same | |
| * key and nonce. | |
| * | |
| * \param ctx The ChaCha20 context to use for encryption or decryption. | |
| * It must be initialized and bound to a key and nonce. | |
| * \param size The length of the input data in Bytes. | |
| * \param input The buffer holding the input data. | |
| * This pointer can be \c NULL if `size == 0`. | |
| * \param output The buffer holding the output data. | |
| * This must be able to hold \p size Bytes. | |
| * This pointer can be \c NULL if `size == 0`. | |
| * | |
| * \return \c 0 on success. | |
| * \return A negative error code on failure. | |
| */ | |
| int mbedtls_chacha20_update( mbedtls_chacha20_context *ctx, | |
| size_t size, | |
| const unsigned char *input, | |
| unsigned char *output ); | |
| /** | |
| * \brief This function encrypts or decrypts data with ChaCha20 and | |
| * the given key and nonce. | |
| * | |
| * Since ChaCha20 is a stream cipher, the same operation is | |
| * used for encrypting and decrypting data. | |
| * | |
| * \warning You must never use the same (key, nonce) pair more than | |
| * once. This would void any confidentiality guarantees for | |
| * the messages encrypted with the same nonce and key. | |
| * | |
| * \note The \p input and \p output pointers must either be equal or | |
| * point to non-overlapping buffers. | |
| * | |
| * \param key The encryption/decryption key. | |
| * This must be \c 32 Bytes in length. | |
| * \param nonce The nonce. This must be \c 12 Bytes in size. | |
| * \param counter The initial counter value. This is usually \c 0. | |
| * \param size The length of the input data in Bytes. | |
| * \param input The buffer holding the input data. | |
| * This pointer can be \c NULL if `size == 0`. | |
| * \param output The buffer holding the output data. | |
| * This must be able to hold \p size Bytes. | |
| * This pointer can be \c NULL if `size == 0`. | |
| * | |
| * \return \c 0 on success. | |
| * \return A negative error code on failure. | |
| */ | |
| int mbedtls_chacha20_crypt( const unsigned char key[32], | |
| const unsigned char nonce[12], | |
| uint32_t counter, | |
| size_t size, | |
| const unsigned char* input, | |
| unsigned char* output ); | |
| #if defined(MBEDTLS_SELF_TEST) | |
| /** | |
| * \brief The ChaCha20 checkup routine. | |
| * | |
| * \return \c 0 on success. | |
| * \return \c 1 on failure. | |
| */ | |
| int mbedtls_chacha20_self_test( int verbose ); | |
| #endif /* MBEDTLS_SELF_TEST */ | |
| #ifdef __cplusplus | |
| } | |
| #endif | |
| #endif /* MBEDTLS_CHACHA20_H */ |