hash.h

/** \file hash.h
  *
  * \brief Describes functions and types common to all hash calculations.
  *
  * This file is licensed as described by the file LICENCE.
  */

#ifndef HASH_H_INCLUDED
#define HASH_H_INCLUDED

#include "common.h"

/** Container for common hash state. */
typedef struct HashStateStruct
{
	/** Where final hash value will be placed. Depending on the size of the
	  * hash function's output, not all entries will be filled. */
	uint32_t h[8];
	/** Current index into HashState#m, ranges from 0 to 15. */
	uint8_t index_m;
	/** Current byte within (32 bit) word of HashState#m. For big-endian hash
	  * functions, 0 = MSB, 3 = LSB. For little-endian hash functions,
	  * 0 = LSB, 3 = MSB. */
	uint8_t byte_position_m;
	/** If this is true, each (32 bit) word in the message buffer will be
	  * loaded in a big-endian manner. If this is false, the words will be
	  * loaded in a little-endian manner. This also affects how the final hash
	  * value is calculated. */
	bool is_big_endian;
	/** 512 bit message buffer. */
	uint32_t m[16];
	/** Total length of message; updated as bytes are written. */
	uint32_t message_length;
	/** Callback to update hash value when message buffer is full. */
	void (*hashBlock)(struct HashStateStruct *hs2);
} HashState;

extern void clearM(HashState *hs);
extern void hashWriteByte(HashState *hs, uint8_t byte);
extern void hashFinish(HashState *hs);
extern void writeHashToByteArray(uint8_t *out, HashState *hs, bool do_write_big_endian);

#endif // #ifndef HASH_H_INCLUDED