/*
 * Copyright (C) 1999, 2002 Aladdin Enterprises.  All rights reserved.
 *
 * This software is provided 'as-is', without any express or implied
 * warranty.  In no event will the authors be held liable for any damages
 * arising from the use of this software.
 *
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 *
 * 1. The origin of this software must not be misrepresented; you must not
 *	claim that you wrote the original software. If you use this software
 *	in a product, an acknowledgment in the product documentation would be
 *	appreciated but is not required.
 * 2. Altered source versions must be plainly marked as such, and must not be
 *	misrepresented as being the original software.
 * 3. This notice may not be removed or altered from any source distribution.
 *
 * L. Peter Deutsch
 * ghost@aladdin.com
 */

/* Minor modifications done to remove some code and change style. */

#include "util_md5.h"
#include "util_path.h"

#include <string.h>
#include <stdio.h>

CCL_NAMESPACE_BEGIN

#define T_MASK ((uint32_t)~0)
#define T1 /* 0xd76aa478 */ (T_MASK ^ 0x28955b87)
#define T2 /* 0xe8c7b756 */ (T_MASK ^ 0x173848a9)
#define T3	0x242070db
#define T4 /* 0xc1bdceee */ (T_MASK ^ 0x3e423111)
#define T5 /* 0xf57c0faf */ (T_MASK ^ 0x0a83f050)
#define T6	0x4787c62a
#define T7 /* 0xa8304613 */ (T_MASK ^ 0x57cfb9ec)
#define T8 /* 0xfd469501 */ (T_MASK ^ 0x02b96afe)
#define T9	0x698098d8
#define T10 /* 0x8b44f7af */ (T_MASK ^ 0x74bb0850)
#define T11 /* 0xffff5bb1 */ (T_MASK ^ 0x0000a44e)
#define T12 /* 0x895cd7be */ (T_MASK ^ 0x76a32841)
#define T13	0x6b901122
#define T14 /* 0xfd987193 */ (T_MASK ^ 0x02678e6c)
#define T15 /* 0xa679438e */ (T_MASK ^ 0x5986bc71)
#define T16	0x49b40821
#define T17 /* 0xf61e2562 */ (T_MASK ^ 0x09e1da9d)
#define T18 /* 0xc040b340 */ (T_MASK ^ 0x3fbf4cbf)
#define T19	0x265e5a51
#define T20 /* 0xe9b6c7aa */ (T_MASK ^ 0x16493855)
#define T21 /* 0xd62f105d */ (T_MASK ^ 0x29d0efa2)
#define T22	0x02441453
#define T23 /* 0xd8a1e681 */ (T_MASK ^ 0x275e197e)
#define T24 /* 0xe7d3fbc8 */ (T_MASK ^ 0x182c0437)
#define T25	0x21e1cde6
#define T26 /* 0xc33707d6 */ (T_MASK ^ 0x3cc8f829)
#define T27 /* 0xf4d50d87 */ (T_MASK ^ 0x0b2af278)
#define T28	0x455a14ed
#define T29 /* 0xa9e3e905 */ (T_MASK ^ 0x561c16fa)
#define T30 /* 0xfcefa3f8 */ (T_MASK ^ 0x03105c07)
#define T31	0x676f02d9
#define T32 /* 0x8d2a4c8a */ (T_MASK ^ 0x72d5b375)
#define T33 /* 0xfffa3942 */ (T_MASK ^ 0x0005c6bd)
#define T34 /* 0x8771f681 */ (T_MASK ^ 0x788e097e)
#define T35	0x6d9d6122
#define T36 /* 0xfde5380c */ (T_MASK ^ 0x021ac7f3)
#define T37 /* 0xa4beea44 */ (T_MASK ^ 0x5b4115bb)
#define T38	0x4bdecfa9
#define T39 /* 0xf6bb4b60 */ (T_MASK ^ 0x0944b49f)
#define T40 /* 0xbebfbc70 */ (T_MASK ^ 0x4140438f)
#define T41	0x289b7ec6
#define T42 /* 0xeaa127fa */ (T_MASK ^ 0x155ed805)
#define T43 /* 0xd4ef3085 */ (T_MASK ^ 0x2b10cf7a)
#define T44	0x04881d05
#define T45 /* 0xd9d4d039 */ (T_MASK ^ 0x262b2fc6)
#define T46 /* 0xe6db99e5 */ (T_MASK ^ 0x1924661a)
#define T47	0x1fa27cf8
#define T48 /* 0xc4ac5665 */ (T_MASK ^ 0x3b53a99a)
#define T49 /* 0xf4292244 */ (T_MASK ^ 0x0bd6ddbb)
#define T50	0x432aff97
#define T51 /* 0xab9423a7 */ (T_MASK ^ 0x546bdc58)
#define T52 /* 0xfc93a039 */ (T_MASK ^ 0x036c5fc6)
#define T53	0x655b59c3
#define T54 /* 0x8f0ccc92 */ (T_MASK ^ 0x70f3336d)
#define T55 /* 0xffeff47d */ (T_MASK ^ 0x00100b82)
#define T56 /* 0x85845dd1 */ (T_MASK ^ 0x7a7ba22e)
#define T57	0x6fa87e4f
#define T58 /* 0xfe2ce6e0 */ (T_MASK ^ 0x01d3191f)
#define T59 /* 0xa3014314 */ (T_MASK ^ 0x5cfebceb)
#define T60	0x4e0811a1
#define T61 /* 0xf7537e82 */ (T_MASK ^ 0x08ac817d)
#define T62 /* 0xbd3af235 */ (T_MASK ^ 0x42c50dca)
#define T63	0x2ad7d2bb
#define T64 /* 0xeb86d391 */ (T_MASK ^ 0x14792c6e)

void MD5Hash::process(const uint8_t *data /*[64]*/)
{
	uint32_t
	a = abcd[0], b = abcd[1],
	c = abcd[2], d = abcd[3];
	uint32_t t;
	/* Define storage for little-endian or both types of CPUs. */
	uint32_t xbuf[16];
	const uint32_t *X;

	{
		/*
		 * Determine dynamically whether this is a big-endian or
		 * little-endian machine, since we can use a more efficient
		 * algorithm on the latter.
		 */
		static const int w = 1;

		if(*((const uint8_t *)&w)) /* dynamic little-endian */
		{
			/*
			 * On little-endian machines, we can process properly aligned
			 * data without copying it.
			 */
			if(!((data - (const uint8_t *)0) & 3)) {
				/* data are properly aligned */
				X = (const uint32_t *)data;
			}
			else {
			/* not aligned */
			memcpy(xbuf, data, 64);
			X = xbuf;
			}
		}
		else { /* dynamic big-endian */
			/*
			 * On big-endian machines, we must arrange the bytes in the
			 * right order.
			 */
			const uint8_t *xp = data;
			int i;

			X = xbuf;		/* (dynamic only) */
			for(i = 0; i < 16; ++i, xp += 4)
			xbuf[i] = xp[0] + (xp[1] << 8) + (xp[2] << 16) + (xp[3] << 24);
		}
	}

#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32 - (n))))

	/* Round 1. */
	/* Let [abcd k s i] denote the operation
	 * a = b + ((a + F(b,c,d) + X[k] + T[i]) <<< s). */
#define F(x, y, z) (((x) & (y)) | (~(x) & (z)))
#define SET(a, b, c, d, k, s, Ti)\
  t = a + F(b,c,d) + X[k] + Ti;\
  a = ROTATE_LEFT(t, s) + b
	/* Do the following 16 operations. */
	SET(a, b, c, d,  0,  7,  T1);
	SET(d, a, b, c,  1, 12,  T2);
	SET(c, d, a, b,  2, 17,  T3);
	SET(b, c, d, a,  3, 22,  T4);
	SET(a, b, c, d,  4,  7,  T5);
	SET(d, a, b, c,  5, 12,  T6);
	SET(c, d, a, b,  6, 17,  T7);
	SET(b, c, d, a,  7, 22,  T8);
	SET(a, b, c, d,  8,  7,  T9);
	SET(d, a, b, c,  9, 12, T10);
	SET(c, d, a, b, 10, 17, T11);
	SET(b, c, d, a, 11, 22, T12);
	SET(a, b, c, d, 12,  7, T13);
	SET(d, a, b, c, 13, 12, T14);
	SET(c, d, a, b, 14, 17, T15);
	SET(b, c, d, a, 15, 22, T16);
#undef SET

	/* Round 2. */
	/* Let [abcd k s i] denote the operation
	 * a = b + ((a + G(b,c,d) + X[k] + T[i]) <<< s). */
#define G(x, y, z) (((x) & (z)) | ((y) & ~(z)))
#define SET(a, b, c, d, k, s, Ti)\
  t = a + G(b,c,d) + X[k] + Ti;\
  a = ROTATE_LEFT(t, s) + b
	 /* Do the following 16 operations. */
	SET(a, b, c, d,  1,  5, T17);
	SET(d, a, b, c,  6,  9, T18);
	SET(c, d, a, b, 11, 14, T19);
	SET(b, c, d, a,  0, 20, T20);
	SET(a, b, c, d,  5,  5, T21);
	SET(d, a, b, c, 10,  9, T22);
	SET(c, d, a, b, 15, 14, T23);
	SET(b, c, d, a,  4, 20, T24);
	SET(a, b, c, d,  9,  5, T25);
	SET(d, a, b, c, 14,  9, T26);
	SET(c, d, a, b,  3, 14, T27);
	SET(b, c, d, a,  8, 20, T28);
	SET(a, b, c, d, 13,  5, T29);
	SET(d, a, b, c,  2,  9, T30);
	SET(c, d, a, b,  7, 14, T31);
	SET(b, c, d, a, 12, 20, T32);
#undef SET

	/* Round 3. */
	/* Let [abcd k s t] denote the operation
	 * a = b + ((a + H(b,c,d) + X[k] + T[i]) <<< s). */
#define H(x, y, z) ((x) ^ (y) ^ (z))
#define SET(a, b, c, d, k, s, Ti)\
  t = a + H(b,c,d) + X[k] + Ti;\
  a = ROTATE_LEFT(t, s) + b
	 /* Do the following 16 operations. */
	SET(a, b, c, d,  5,  4, T33);
	SET(d, a, b, c,  8, 11, T34);
	SET(c, d, a, b, 11, 16, T35);
	SET(b, c, d, a, 14, 23, T36);
	SET(a, b, c, d,  1,  4, T37);
	SET(d, a, b, c,  4, 11, T38);
	SET(c, d, a, b,  7, 16, T39);
	SET(b, c, d, a, 10, 23, T40);
	SET(a, b, c, d, 13,  4, T41);
	SET(d, a, b, c,  0, 11, T42);
	SET(c, d, a, b,  3, 16, T43);
	SET(b, c, d, a,  6, 23, T44);
	SET(a, b, c, d,  9,  4, T45);
	SET(d, a, b, c, 12, 11, T46);
	SET(c, d, a, b, 15, 16, T47);
	SET(b, c, d, a,  2, 23, T48);
#undef SET

	/* Round 4. */
	/* Let [abcd k s t] denote the operation
	 * a = b + ((a + I(b,c,d) + X[k] + T[i]) <<< s). */
#define I(x, y, z) ((y) ^ ((x) | ~(z)))
#define SET(a, b, c, d, k, s, Ti)\
  t = a + I(b,c,d) + X[k] + Ti;\
  a = ROTATE_LEFT(t, s) + b
	 /* Do the following 16 operations. */
	SET(a, b, c, d,  0,  6, T49);
	SET(d, a, b, c,  7, 10, T50);
	SET(c, d, a, b, 14, 15, T51);
	SET(b, c, d, a,  5, 21, T52);
	SET(a, b, c, d, 12,  6, T53);
	SET(d, a, b, c,  3, 10, T54);
	SET(c, d, a, b, 10, 15, T55);
	SET(b, c, d, a,  1, 21, T56);
	SET(a, b, c, d,  8,  6, T57);
	SET(d, a, b, c, 15, 10, T58);
	SET(c, d, a, b,  6, 15, T59);
	SET(b, c, d, a, 13, 21, T60);
	SET(a, b, c, d,  4,  6, T61);
	SET(d, a, b, c, 11, 10, T62);
	SET(c, d, a, b,  2, 15, T63);
	SET(b, c, d, a,  9, 21, T64);
#undef SET

	/* Then perform the following additions. (That is increment each
	 * of the four registers by the value it had before this block
	 * was started.) */
	abcd[0] += a;
	abcd[1] += b;
	abcd[2] += c;
	abcd[3] += d;
}

MD5Hash::MD5Hash()
{
	count[0] = count[1] = 0;
	abcd[0] = 0x67452301;
	abcd[1] = /*0xefcdab89*/ T_MASK ^ 0x10325476;
	abcd[2] = /*0x98badcfe*/ T_MASK ^ 0x67452301;
	abcd[3] = 0x10325476;
}

MD5Hash::~MD5Hash()
{
}

void MD5Hash::append(const uint8_t *data, int nbytes)
{
	const uint8_t *p = data;
	int left = nbytes;
	int offset = (count[0] >> 3) & 63;
	uint32_t nbits = (uint32_t)(nbytes << 3);

	if(nbytes <= 0)
		return;

	/* Update the message length. */
	count[1] += nbytes >> 29;
	count[0] += nbits;
	if(count[0] < nbits)
		count[1]++;

	/* Process an initial partial block. */
	if(offset) {
		int copy = (offset + nbytes > 64 ? 64 - offset : nbytes);

		memcpy(buf + offset, p, copy);
		if(offset + copy < 64)
			return;
		p += copy;
		left -= copy;
		process(buf);
	}

	/* Process full blocks. */
	for(; left >= 64; p += 64, left -= 64)
		process(p);

	/* Process a final partial block. */
	if(left)
		memcpy(buf, p, left);
}

bool MD5Hash::append_file(const string& filepath)
{
	FILE *f = path_fopen(filepath, "rb");

	if(!f) {
		fprintf(stderr, "MD5: failed to open file %s\n", filepath.c_str());
		return false;
	}

	const size_t buffer_size = 1024;
	uint8_t buffer[buffer_size];
	size_t n;

	do {
		n = fread(buffer, 1, buffer_size, f);
		append(buffer, n);
	} while(n == buffer_size);

	bool success = (ferror(f) == 0);

	fclose(f);
	
	return success;
}

void MD5Hash::finish(uint8_t digest[16])
{
	static const uint8_t pad[64] = {
		0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

	uint8_t data[8];
	int i;

	/* Save the length before padding. */
	for(i = 0; i < 8; ++i)
		data[i] = (uint8_t)(count[i >> 2] >> ((i & 3) << 3));

	/* Pad to 56 bytes mod 64. */
	append(pad, ((55 - (count[0] >> 3)) & 63) + 1);
	/* Append the length. */
	append(data, 8);

	for(i = 0; i < 16; ++i)
		digest[i] = (uint8_t)(abcd[i >> 2] >> ((i & 3) << 3));
}

string MD5Hash::get_hex()
{
	uint8_t digest[16];
	char buf[16*2+1];

	finish(digest);

	for(int i = 0; i < 16; i++)
		sprintf(buf + i*2, "%02X", (unsigned int)digest[i]);
	buf[sizeof(buf)-1] = '\0';
	
	return string(buf);
}

CCL_NAMESPACE_END