include/zephyr/sys/base64.h

/*
 * RFC 1521 base64 encoding/decoding
 *
 * Copyright (C) 2018, Nordic Semiconductor ASA
 * Copyright (C) 2006-2015, ARM Limited, 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.
 *
 * Adapted for Zephyr by Carles Cufi (carles.cufi@nordicsemi.no)
 *  - Removed mbedtls_ prefixes
 *  - Reworked coding style
 */
#ifndef ZEPHYR_INCLUDE_SYS_BASE64_H_
#define ZEPHYR_INCLUDE_SYS_BASE64_H_

#include <stddef.h>
#include <zephyr/types.h>

#ifdef __cplusplus
extern "C" {
#endif

/**
 * @file
 *
 * @defgroup base64 Base64
 * @brief Base64 encoding/decoding functions
 * @ingroup utilities
 * @{
 */

/**
 * @brief          Encode a buffer into base64 format
 *
 * @param dst      destination buffer
 * @param dlen     size of the destination buffer
 * @param olen     number of bytes written
 * @param src      source buffer
 * @param slen     amount of data to be encoded
 *
 * @return         0 if successful, or -ENOMEM if the buffer is too small.
 *                 *olen is always updated to reflect the amount
 *                 of data that has (or would have) been written.
 *                 If that length cannot be represented, then no data is
 *                 written to the buffer and *olen is set to the maximum
 *                 length representable as a size_t.
 *
 * @note           Call this function with dlen = 0 to obtain the
 *                 required buffer size in *olen
 */
int base64_encode(uint8_t *dst, size_t dlen, size_t *olen, const uint8_t *src,
		  size_t slen);

/**
 * @brief          Decode a base64-formatted buffer
 *
 * @param dst      destination buffer (can be NULL for checking size)
 * @param dlen     size of the destination buffer
 * @param olen     number of bytes written
 * @param src      source buffer
 * @param slen     amount of data to be decoded
 *
 * @return         0 if successful, -ENOMEM, or -EINVAL if the input data is
 *                 not correct. *olen is always updated to reflect the amount
 *                 of data that has (or would have) been written.
 *
 * @note           Call this function with *dst = NULL or dlen = 0 to obtain
 *                 the required buffer size in *olen
 */
int base64_decode(uint8_t *dst, size_t dlen, size_t *olen, const uint8_t *src,
		  size_t slen);

/**
 * @}
 */

#ifdef __cplusplus
}
#endif

#endif /* ZEPHYR_INCLUDE_SYS_BASE64_H_ */