/*
 * This is an OpenSSL-compatible implementation of the RSA Data Security, Inc.
 * MD5 Message-Digest Algorithm (RFC 1321).
 *
 * Homepage:
 * http://openwall.info/wiki/people/solar/software/public-domain-source-code/md5
 *
 * Author:
 * Alexander Peslyak, better known as Solar Designer <solar at openwall.com>
 *
 * This software was written by Alexander Peslyak in 2001.  No copyright is
 * claimed, and the software is hereby placed in the public domain.
 * In case this attempt to disclaim copyright and place the software in the
 * public domain is deemed null and void, then the software is
 * Copyright (c) 2001 Alexander Peslyak and it is hereby released to the
 * general public under the following terms:
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted.
 *
 * There's ABSOLUTELY NO WARRANTY, express or implied.
 *
 * (This is a heavily cut-down "BSD license".)
 *
 * This differs from Colin Plumb's older public domain implementation in that
 * no exactly 32-bit integer data type is required (any 32-bit or wider
 * unsigned integer data type will do), there's no compile-time endianness
 * configuration, and the function prototypes match OpenSSL's.  No code from
 * Colin Plumb's implementation has been reused; this comment merely compares
 * the properties of the two independent implementations.
 *
 * The primary goals of this implementation are portability and ease of use.
 * It is meant to be fast, but not as fast as possible.  Some known
 * optimizations are not included to reduce source code size and avoid
 * compile-time configuration.
 */

#ifndef HAVE_OPENSSL

#include <string.h>

#include "md5.h"

/*
 * The basic MD5 functions.
 *
 * F and G are optimized compared to their RFC 1321 definitions for
 * architectures that lack an AND-NOT instruction, just like in Colin Plumb's
 * implementation.
 */
#define F(x, y, z)			((z) ^ ((x) & ((y) ^ (z))))
#define G(x, y, z)			((y) ^ ((z) & ((x) ^ (y))))
#define H(x, y, z)			((x) ^ (y) ^ (z))
#define I(x, y, z)			((y) ^ ((x) | ~(z)))

/*
 * The MD5 transformation for all four rounds.
 */
#define STEP(f, a, b, c, d, x, t, s) \
	(a) += f((b), (c), (d)) + (x) + (t); \
	(a) = (((a) << (s)) | (((a) & 0xffffffff) >> (32 - (s)))); \
	(a) += (b);

/*
 * SET reads 4 input bytes in little-endian byte order and stores them
 * in a properly aligned word in host byte order.
 *
 * The check for little-endian architectures that tolerate unaligned
 * memory accesses is just an optimization.  Nothing will break if it
 * doesn't work.
 */
#if defined(__i386__) || defined(__x86_64__) || defined(__vax__)
#define SET(n) \
	(*(MD5_u32plus *)&ptr[(n) * 4])
#define GET(n) \
	SET(n)
#else
#define SET(n) \
	(ctx->block[(n)] = \
	(MD5_u32plus)ptr[(n) * 4] | \
	((MD5_u32plus)ptr[(n) * 4 + 1] << 8) | \
	((MD5_u32plus)ptr[(n) * 4 + 2] << 16) | \
	((MD5_u32plus)ptr[(n) * 4 + 3] << 24))
#define GET(n) \
	(ctx->block[(n)])
#endif

/*
 * This processes one or more 64-byte data blocks, but does NOT update
 * the bit counters.  There are no alignment requirements.
 */
static void *
body (MD5_CTX * ctx, void *data, unsigned long size)
{
    unsigned char *ptr;
    MD5_u32plus a, b, c, d;
    MD5_u32plus saved_a, saved_b, saved_c, saved_d;

    ptr = data;

    a = ctx->a;
    b = ctx->b;
    c = ctx->c;
    d = ctx->d;

    do
      {
	  saved_a = a;
	  saved_b = b;
	  saved_c = c;
	  saved_d = d;

/* Round 1 */
	  STEP (F, a, b, c, d, SET (0), 0xd76aa478, 7)
	      STEP (F, d, a, b, c, SET (1), 0xe8c7b756, 12)
	      STEP (F, c, d, a, b, SET (2), 0x242070db, 17)
	      STEP (F, b, c, d, a, SET (3), 0xc1bdceee, 22)
	      STEP (F, a, b, c, d, SET (4), 0xf57c0faf, 7)
	      STEP (F, d, a, b, c, SET (5), 0x4787c62a, 12)
	      STEP (F, c, d, a, b, SET (6), 0xa8304613, 17)
	      STEP (F, b, c, d, a, SET (7), 0xfd469501, 22)
	      STEP (F, a, b, c, d, SET (8), 0x698098d8, 7)
	      STEP (F, d, a, b, c, SET (9), 0x8b44f7af, 12)
	      STEP (F, c, d, a, b, SET (10), 0xffff5bb1, 17)
	      STEP (F, b, c, d, a, SET (11), 0x895cd7be, 22)
	      STEP (F, a, b, c, d, SET (12), 0x6b901122, 7)
	      STEP (F, d, a, b, c, SET (13), 0xfd987193, 12)
	      STEP (F, c, d, a, b, SET (14), 0xa679438e, 17)
	      STEP (F, b, c, d, a, SET (15), 0x49b40821, 22)
/* Round 2 */
	      STEP (G, a, b, c, d, GET (1), 0xf61e2562, 5)
	      STEP (G, d, a, b, c, GET (6), 0xc040b340, 9)
	      STEP (G, c, d, a, b, GET (11), 0x265e5a51, 14)
	      STEP (G, b, c, d, a, GET (0), 0xe9b6c7aa, 20)
	      STEP (G, a, b, c, d, GET (5), 0xd62f105d, 5)
	      STEP (G, d, a, b, c, GET (10), 0x02441453, 9)
	      STEP (G, c, d, a, b, GET (15), 0xd8a1e681, 14)
	      STEP (G, b, c, d, a, GET (4), 0xe7d3fbc8, 20)
	      STEP (G, a, b, c, d, GET (9), 0x21e1cde6, 5)
	      STEP (G, d, a, b, c, GET (14), 0xc33707d6, 9)
	      STEP (G, c, d, a, b, GET (3), 0xf4d50d87, 14)
	      STEP (G, b, c, d, a, GET (8), 0x455a14ed, 20)
	      STEP (G, a, b, c, d, GET (13), 0xa9e3e905, 5)
	      STEP (G, d, a, b, c, GET (2), 0xfcefa3f8, 9)
	      STEP (G, c, d, a, b, GET (7), 0x676f02d9, 14)
	      STEP (G, b, c, d, a, GET (12), 0x8d2a4c8a, 20)
/* Round 3 */
	      STEP (H, a, b, c, d, GET (5), 0xfffa3942, 4)
	      STEP (H, d, a, b, c, GET (8), 0x8771f681, 11)
	      STEP (H, c, d, a, b, GET (11), 0x6d9d6122, 16)
	      STEP (H, b, c, d, a, GET (14), 0xfde5380c, 23)
	      STEP (H, a, b, c, d, GET (1), 0xa4beea44, 4)
	      STEP (H, d, a, b, c, GET (4), 0x4bdecfa9, 11)
	      STEP (H, c, d, a, b, GET (7), 0xf6bb4b60, 16)
	      STEP (H, b, c, d, a, GET (10), 0xbebfbc70, 23)
	      STEP (H, a, b, c, d, GET (13), 0x289b7ec6, 4)
	      STEP (H, d, a, b, c, GET (0), 0xeaa127fa, 11)
	      STEP (H, c, d, a, b, GET (3), 0xd4ef3085, 16)
	      STEP (H, b, c, d, a, GET (6), 0x04881d05, 23)
	      STEP (H, a, b, c, d, GET (9), 0xd9d4d039, 4)
	      STEP (H, d, a, b, c, GET (12), 0xe6db99e5, 11)
	      STEP (H, c, d, a, b, GET (15), 0x1fa27cf8, 16)
	      STEP (H, b, c, d, a, GET (2), 0xc4ac5665, 23)
/* Round 4 */
	      STEP (I, a, b, c, d, GET (0), 0xf4292244, 6)
	      STEP (I, d, a, b, c, GET (7), 0x432aff97, 10)
	      STEP (I, c, d, a, b, GET (14), 0xab9423a7, 15)
	      STEP (I, b, c, d, a, GET (5), 0xfc93a039, 21)
	      STEP (I, a, b, c, d, GET (12), 0x655b59c3, 6)
	      STEP (I, d, a, b, c, GET (3), 0x8f0ccc92, 10)
	      STEP (I, c, d, a, b, GET (10), 0xffeff47d, 15)
	      STEP (I, b, c, d, a, GET (1), 0x85845dd1, 21)
	      STEP (I, a, b, c, d, GET (8), 0x6fa87e4f, 6)
	      STEP (I, d, a, b, c, GET (15), 0xfe2ce6e0, 10)
	      STEP (I, c, d, a, b, GET (6), 0xa3014314, 15)
	      STEP (I, b, c, d, a, GET (13), 0x4e0811a1, 21)
	      STEP (I, a, b, c, d, GET (4), 0xf7537e82, 6)
	      STEP (I, d, a, b, c, GET (11), 0xbd3af235, 10)
	      STEP (I, c, d, a, b, GET (2), 0x2ad7d2bb, 15)
	      STEP (I, b, c, d, a, GET (9), 0xeb86d391, 21) a += saved_a;
	  b += saved_b;
	  c += saved_c;
	  d += saved_d;

	  ptr += 64;
      }
    while (size -= 64);

    ctx->a = a;
    ctx->b = b;
    ctx->c = c;
    ctx->d = d;

    return ptr;
}

/* 
  Sandro Furieri - SpatiaLite - 2013-06-03 

  simply re-declaring all these functions as PRIVATE
  (not externally visible outside libspatialite itself)
*/

MD5_PRIVATE void
splite_MD5_Init (MD5_CTX * ctx)
{
    ctx->a = 0x67452301;
    ctx->b = 0xefcdab89;
    ctx->c = 0x98badcfe;
    ctx->d = 0x10325476;

    ctx->lo = 0;
    ctx->hi = 0;
}

MD5_PRIVATE void
splite_MD5_Update (MD5_CTX * ctx, void *data, unsigned long size)
{
    MD5_u32plus saved_lo;
    unsigned long used, free;

    saved_lo = ctx->lo;
    if ((ctx->lo = (saved_lo + size) & 0x1fffffff) < saved_lo)
	ctx->hi++;
    ctx->hi += size >> 29;

    used = saved_lo & 0x3f;

    if (used)
      {
	  free = 64 - used;

	  if (size < free)
	    {
		memcpy (&ctx->buffer[used], data, size);
		return;
	    }

	  memcpy (&ctx->buffer[used], data, free);
	  data = (unsigned char *) data + free;
	  size -= free;
	  body (ctx, ctx->buffer, 64);
      }

    if (size >= 64)
      {
	  data = body (ctx, data, size & ~(unsigned long) 0x3f);
	  size &= 0x3f;
      }

    memcpy (ctx->buffer, data, size);
}

MD5_PRIVATE void
splite_MD5_Final (unsigned char *result, MD5_CTX * ctx)
{
    unsigned long used, free;

    used = ctx->lo & 0x3f;

    ctx->buffer[used++] = 0x80;

    free = 64 - used;

    if (free < 8)
      {
	  memset (&ctx->buffer[used], 0, free);
	  body (ctx, ctx->buffer, 64);
	  used = 0;
	  free = 64;
      }

    memset (&ctx->buffer[used], 0, free - 8);

    ctx->lo <<= 3;
    ctx->buffer[56] = (char) (ctx->lo);
    ctx->buffer[57] = (char) (ctx->lo >> 8);
    ctx->buffer[58] = (char) (ctx->lo >> 16);
    ctx->buffer[59] = (char) (ctx->lo >> 24);
    ctx->buffer[60] = (char) (ctx->hi);
    ctx->buffer[61] = (char) (ctx->hi >> 8);
    ctx->buffer[62] = (char) (ctx->hi >> 16);
    ctx->buffer[63] = (char) (ctx->hi >> 24);

    body (ctx, ctx->buffer, 64);

    result[0] = (char) (ctx->a);
    result[1] = (char) (ctx->a >> 8);
    result[2] = (char) (ctx->a >> 16);
    result[3] = (char) (ctx->a >> 24);
    result[4] = (char) (ctx->b);
    result[5] = (char) (ctx->b >> 8);
    result[6] = (char) (ctx->b >> 16);
    result[7] = (char) (ctx->b >> 24);
    result[8] = (char) (ctx->c);
    result[9] = (char) (ctx->c >> 8);
    result[10] = (char) (ctx->c >> 16);
    result[11] = (char) (ctx->c >> 24);
    result[12] = (char) (ctx->d);
    result[13] = (char) (ctx->d >> 8);
    result[14] = (char) (ctx->d >> 16);
    result[15] = (char) (ctx->d >> 24);

    memset (ctx, 0, sizeof (*ctx));
}

#endif
