pinebuds/utils/encrypt/_sha256.h
2022-08-15 17:20:27 +08:00

86 lines
2.7 KiB
C

/** @file
*
* @defgroup sha256 SHA-256 hash library
* @{
* @ingroup app_common
*
* @brief This module calculates SHA-256 (SHA-2, FIPS-180) hashes.
*
* @details To use this module, first call @ref sha256_init on a @ref sha256_context_t instance. Then call @ref
* sha256_update with the data to be hashed. This step can optionally be done with multiple
* calls to @ref sha256_update, each with a section of the data (in the correct order).
* After all data has been passed to @ref sha256_update, call @ref sha256_final to finalize
* and extract the hash value.
*
* This code is adapted from code by Brad Conte, retrieved from
* https://github.com/B-Con/crypto-algorithms.
*
*/
#ifndef SHA256_H
#define SHA256_H
#include <stdint.h>
#define SHA256_DIGEST_SIZE 32
/**@brief Current state of a hash operation.
*/
typedef struct {
uint64_t count;
union {
uint8_t buf[64];
uint32_t buf32[64 / 4];
};
uint32_t state[8]; // upto SHA2
}SHA256_CTX;
/**@brief Function for initializing a @ref sha256_context_t instance.
*
* @param[out] ctx Context instance to be initialized.
*
* @retval BES_SUCCESS If the instance was successfully initialized.
* @retval BES_ERROR_NULL If the parameter was NULL.
*/
uint32_t _sha256_init(SHA256_CTX *ctx);
/**@brief Function for calculating the hash of an array of uint8_t data.
*
* @details This function can be called multiple times in sequence. This is equivalent to calling
* the function once on a concatenation of the data from the different calls.
*
* @param[in,out] ctx Hash instance.
* @param[in] data Data to be hashed.
* @param[in] len Length of the data to be hashed.
*
* @retval BES_SUCCESS If the data was successfully hashed.
* @retval BES_ERROR_NULL If the ctx parameter was NULL or the data parameter was NULL, while the len parameter was not zero.
*/
uint32_t _sha256_update(SHA256_CTX *ctx, const uint8_t * data, uint32_t len);
/**@brief Function for extracting the hash value from a hash instance.
*
* @details This function should be called after all data to be hashed has been passed to the hash
* instance (by one or more calls to @ref sha256_update).
*
* Do not call @ref sha256_update again after @ref sha256_final has been called.
*
* @param[in,out] ctx Hash instance.
* @param[out] hash Array to hold the extracted hash value (assumed to be 32 bytes long).
* @param[in] le Store the hash in little-endian.
*
* @retval BES_SUCCESS If the has value was successfully extracted.
* @retval BES_ERROR_NULL If a parameter was NULL.
*/
uint32_t _sha256_final(SHA256_CTX *ctx, uint8_t * hash, uint8_t le);
#ifdef __cplusplus
}
#endif
#endif // SHA256_H
/** @} */