#ifndef _SHA256_H#define _SHA256_H#ifndef uint8#define uint8  unsigned char#endif#ifndef uint32#define uint32 unsigned long int#endiftypedef struct{    uint32 total[2];    uint32 state[8];    uint8 buffer[64];}sha256_context;void sha256_starts( sha256_context *ctx );void sha256_update( sha256_context *ctx, uint8 *input, uint32 length );void sha256_finish( sha256_context *ctx, uint8 digest[32] );#endif /* sha256.h */