text: #ifndef MD5_H
  #define MD5_H
  
  #include <stdint.h>
  
  #define MD5_DIGEST_SIZE		16
  #define MD5_HMAC_BLOCK_SIZE	64
  #define MD5_BLOCK_WORDS		16
  #define MD5_HASH_WORDS		4
  
  #define F1(x, y, z)	(z ^ (x & (y ^ z)))
  #define F2(x, y, z)	F1(z, x, y)
  #define F3(x, y, z)	(x ^ y ^ z)
  #define F4(x, y, z)	(y ^ (x | ~z))
  
  #define MD5STEP(f, w, x, y, z, in, s) \
  	(w += f(x, y, z) + in, w = (w<<s | w>>(32-s)) + x)
  
  struct fio_md5_ctx {
  	uint32_t *hash;
  	uint32_t block[MD5_BLOCK_WORDS];
  	uint64_t byte_count;
  };
  
  extern void fio_md5_update(struct fio_md5_ctx *, const uint8_t *, unsigned int);
  extern void fio_md5_init(struct fio_md5_ctx *);
  
  #endif
  