/* md5.h - Declaration of functions and data types used for MD5 sum
   computing library functions.
   Copyright (C) 1995, 1996, 1999 Free Software Foundation, Inc.
   NOTE: The canonical source of this file is maintained with the GNU C
   Library.  Bugs can be reported to bug-glibc@prep.ai.mit.edu.

* SPDX-License-Identifier: GPL-2.0-or-later
*/

#ifndef _MD5_H
#define _MD5_H 1

#include <limits.h>
#include <stdint.h>
typedef uint32_t md5_uint32;
typedef uintptr_t md5_uintptr;

/* Structure to save state of computation between the single steps.  */
struct md5_ctx
{
  md5_uint32 A;
  md5_uint32 B;
  md5_uint32 C;
  md5_uint32 D;

  md5_uint32 total[2];
  md5_uint32 buflen;
  char buffer[128];
};

/*
 * The following three functions are build up the low level used in
 * the function `md5_buffer'.
 */

/* Initialize structure containing state of computation.
   (RFC 1321, 3.3: Step 3)  */
extern void md5_init_ctx (struct md5_ctx *ctx);

/* Starting with the result of former calls of this function (or the
   initialization function update the context for the next LEN bytes
   starting at BUFFER.
   It is necessary that LEN is a multiple of 64!!! */
extern void md5_process_block __P ((const void *buffer, size_t len,
				    struct md5_ctx *ctx));

/* Starting with the result of former calls of this function (or the
   initialization function update the context for the next LEN bytes
   starting at BUFFER.
   It is NOT required that LEN is a multiple of 64.  */
extern void md5_process_bytes __P ((const void *buffer, size_t len,
				    struct md5_ctx *ctx));

/* Process the remaining bytes in the buffer and put result from CTX
   in first 16 bytes following RESBUF.  The result is always in little
   endian byte order, so that a byte-wise output yields to the wanted
   ASCII representation of the message digest.

   IMPORTANT: On some systems it is required that RESBUF be correctly
   aligned for a 32 bits value.  */
extern void *md5_finish_ctx (struct md5_ctx *ctx, void *resbuf);


/* Put result from CTX in first 16 bytes following RESBUF.  The result is
   always in little endian byte order, so that a byte-wise output yields
   to the wanted ASCII representation of the message digest.

   IMPORTANT: On some systems it is required that RESBUF is correctly
   aligned for a 32 bits value.  */
extern void *md5_read_ctx (const struct md5_ctx *ctx, void *resbuf);


/* Compute MD5 message digest for LEN bytes beginning at BUFFER.  The
   result is always in little endian byte order, so that a byte-wise
   output yields to the wanted ASCII representation of the message
   digest.  */
extern void *md5_buffer (const char *buffer, size_t len, void *resblock);

/* The following is from gnupg-1.0.2's cipher/bithelp.h.  */
/* Rotate a 32 bit integer by n bytes */
#if defined __GNUC__ && defined __i386__
static inline md5_uint32
rol(md5_uint32 x, int n)
{
  __asm__("roll %%cl,%0"
	  :"=r" (x)
	  :"0" (x),"c" (n));
  return x;
}
#else
# define rol(x,n) ( ((x) << (n)) | ((x) >> (32-(n))) )
#endif

#endif