sha2.h

SHA家族加密算法实现方式, C语言版本

/**
 * file sha2.h
 */
#ifndef _SHA2_H
#define _SHA2_H

/**
 * brief          SHA-256 context structure
 */
typedef struct
{
    unsigned long total[2];     /*!< number of bytes processed  */
    unsigned long state[8];     /*!< intermediate digest state  */
    unsigned char buffer[64];   /*!< data block being processed */

    unsigned char ipad[64];     /*!< HMAC: inner padding        */
    unsigned char opad[64];     /*!< HMAC: outer padding        */
    int is224;                  /*!< 0 => SHA-256, else SHA-224 */
}
sha2_context;

#ifdef __cplusplus
extern "C" {
#endif

	/**
	 * brief          SHA-256 context setup
	 * param ctx      context to be initialized
	 * param is224    0 = use SHA256, 1 = use SHA224
	 */
	void sha2_starts( sha2_context *ctx, int is224 );

	/**
	 * brief          SHA-256 process buffer
	 * param ctx      SHA-256 context
	 * param input    buffer holding the  data
	 * param ilen     length of the input data
	 */
	void sha2_update( sha2_context *ctx, unsigned char *input, int ilen );

	/**
	 * brief          SHA-256 final digest
	 * param ctx      SHA-256 context
	 * param output   SHA-224/256 checksum result
	 */
	void sha2_finish( sha2_context *ctx, unsigned char output[32] );

#ifdef __cplusplus
}
#endif

#endif /* sha2.h */