/* rmd.h - Declaration of functions and data types used for RMD sum
   computing library functions.
   Copyright (C) 2000 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.

   This program is free software; you can redistribute it and/or modify it
   under the terms of the GNU General Public License as published by the
   Free Software Foundation; either version 2, or (at your option) any
   later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software Foundation,
   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

#ifndef _RMD_H
#define _RMD_H 1

#define RMDsize	160

#include <stdio.h>

#if defined HAVE_LIMITS_H || _LIBC
# include <limits.h>
#endif

/* The following contortions are an attempt to use the C preprocessor
   to determine an unsigned integral type that is 32 bits wide.  An
   alternative approach is to use autoconf's AC_CHECK_SIZEOF macro, but
   doing that would require that the configure script compile and *run*
   the resulting executable.  Locally running cross-compiled executables
   is usually not possible.  */

#ifdef _LIBC
# include <sys/types.h>
typedef u_int32_t rmd_uint32;
#else
# if defined __STDC__ && __STDC__
#  define UINT_MAX_32_BITS 4294967295U
# else
#  define UINT_MAX_32_BITS 0xFFFFFFFF
# endif

/* If UINT_MAX isn't defined, assume it's a 32-bit type.
   This should be valid for all systems GNU cares about because
   that doesn't include 16-bit systems, and only modern systems
   (that certainly have <limits.h>) have 64+-bit integral types.  */

# ifndef UINT_MAX
#  define UINT_MAX UINT_MAX_32_BITS
# endif

# if UINT_MAX == UINT_MAX_32_BITS
   typedef unsigned int rmd_uint32;
# else
#  if USHRT_MAX == UINT_MAX_32_BITS
    typedef unsigned short rmd_uint32;
#  else
#   if ULONG_MAX == UINT_MAX_32_BITS
     typedef unsigned long rmd_uint32;
#   else
     /* The following line is intended to evoke an error.
        Using #error is not portable enough.  */
     "Cannot determine unsigned 32-bit data type."
#   endif
#  endif
# endif
#endif

#undef __P
#if defined (__STDC__) && __STDC__
#define __P(x) x
#else
#define __P(x) ()
#endif

/********************************************************************/

/* typedef 8 and 32 bit types, resp.  */
/* adapt these, if necessary, 
   for your operating system and compiler */
typedef    unsigned char        byte;
/*typedef    __u32        dword;*/


/* Structure to save state of computation between the single steps.  */
struct rmd_ctx
{
  rmd_uint32 A;
  rmd_uint32 B;
  rmd_uint32 C;
  rmd_uint32 D;
  rmd_uint32 E;

  rmd_uint32 total[2];
  rmd_uint32 buflen;
  char buffer[128];
};

#define BLOCKSIZE 4096

/* macro definitions */

/* collect four bytes into one word: */
#define BYTES_TO_DWORD(strptr)                    \
            (((rmd_uint32) *((strptr)+3) << 24) | \
             ((rmd_uint32) *((strptr)+2) << 16) | \
             ((rmd_uint32) *((strptr)+1) <<  8) | \
             ((rmd_uint32) *(strptr)))

/* ROL(x, n) cyclically rotates x over n bits to the left */
/* x must be of an unsigned 32 bits type and 0 <= n < 32. */
#define ROL(x, n)        (((x) << (n)) | ((x) >> (32-(n))))

/* the five basic functions F(), G() and H() */
#define F(x, y, z)        ((x) ^ (y) ^ (z)) 
#define G(x, y, z)        (((x) & (y)) | (~(x) & (z))) 
#define H(x, y, z)        (((x) | ~(y)) ^ (z))
#define I(x, y, z)        (((x) & (z)) | ((y) & ~(z))) 
#define J(x, y, z)        ((x) ^ ((y) | ~(z)))

/* the ten basic operations FF() through III() */
#define FF(a, b, c, d, e, x, s)        {\
      (a) += F((b), (c), (d)) + (x);\
      (a) = ROL((a), (s)) + (e);\
      (c) = ROL((c), 10);\
   }
#define GG(a, b, c, d, e, x, s)        {\
      (a) += G((b), (c), (d)) + (x) + 0x5a827999UL;\
      (a) = ROL((a), (s)) + (e);\
      (c) = ROL((c), 10);\
   }
#define HH(a, b, c, d, e, x, s)        {\
      (a) += H((b), (c), (d)) + (x) + 0x6ed9eba1UL;\
      (a) = ROL((a), (s)) + (e);\
      (c) = ROL((c), 10);\
   }
#define II(a, b, c, d, e, x, s)        {\
      (a) += I((b), (c), (d)) + (x) + 0x8f1bbcdcUL;\
      (a) = ROL((a), (s)) + (e);\
      (c) = ROL((c), 10);\
   }
#define JJ(a, b, c, d, e, x, s)        {\
      (a) += J((b), (c), (d)) + (x) + 0xa953fd4eUL;\
      (a) = ROL((a), (s)) + (e);\
      (c) = ROL((c), 10);\
   }
#define FFF(a, b, c, d, e, x, s)        {\
      (a) += F((b), (c), (d)) + (x);\
      (a) = ROL((a), (s)) + (e);\
      (c) = ROL((c), 10);\
   }
#define GGG(a, b, c, d, e, x, s)        {\
      (a) += G((b), (c), (d)) + (x) + 0x7a6d76e9UL;\
      (a) = ROL((a), (s)) + (e);\
      (c) = ROL((c), 10);\
   }
#define HHH(a, b, c, d, e, x, s)        {\
      (a) += H((b), (c), (d)) + (x) + 0x6d703ef3UL;\
      (a) = ROL((a), (s)) + (e);\
      (c) = ROL((c), 10);\
   }
#define III(a, b, c, d, e, x, s)        {\
      (a) += I((b), (c), (d)) + (x) + 0x5c4dd124UL;\
      (a) = ROL((a), (s)) + (e);\
      (c) = ROL((c), 10);\
   }
#define JJJ(a, b, c, d, e, x, s)        {\
      (a) += J((b), (c), (d)) + (x) + 0x50a28be6UL;\
      (a) = ROL((a), (s)) + (e);\
      (c) = ROL((c), 10);\
   }

/********************************************************************/

/* function prototypes */

/*
 * The following three functions are build up the low level used in
 * the functions `rmd_stream' and `rmd_buffer'.
 */

extern void rmd_init_ctx __P ((struct rmd_ctx *ctx));

void rmd_compress __P ((struct rmd_ctx *ctx, rmd_uint32 *X));
/*
 *  the compression function.
 *  transforms MDbuf using message bytes X[0] through X[15]
 */


/* 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 rmd_process_bytes __P ((byte *buffer, size_t len,
                                    struct rmd_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 is correctly
   aligned for a 32 bits value.  */
extern void *rmd_finish_ctx __P ((struct rmd_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 *rmd_read_ctx __P ((const struct rmd_ctx *ctx, void *resbuf));


/* Compute RMD message digest for bytes read from STREAM.  The
   resulting message digest number will be written into the 16 bytes
   beginning at RESBLOCK.  */
extern int rmd_stream __P ((FILE *stream, void *resblock));

/* Compute RMD 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 *rmd_buffer __P ((void *buffer, rmd_uint32 len, void *resblock));

#endif