ObjFW  Artifact [ae6cec6554]

Artifact ae6cec655481a09037edfacad01979b7ac733b4c17782aa125f763b9a0850b85:

• File src/OFMD5Hash.m — part of check-in [3d16a30f41] at 2013-06-22 12:12:36 on branch trunk — Rework exceptions.

  This mostly removes the argument for the class in which the exception
  occurred. As backtraces were recently added for all platforms, the
  passed class does not give any extra information on where the exception
  occurred anymore.

  This also removes a few other arguments which were not too helpful. In
  the past, the idea was to pass as many arguments as possible so that it
  is easier to find the origin of the exception. However, as backtraces
  are a much better way to find the origin, those are not useful anymore
  and just make the exception more cumbersome to use. The rule is now to
  only pass arguments that might help in recovering from the exception or
  provide information that is otherwise not easily accessible. (user: js, size: 7159) [annotate] [blame] [check-ins using]

/*
 * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013
 *   Jonathan Schleifer <js@webkeks.org>
 *
 * All rights reserved.
 *
 * This file is part of ObjFW. It may be distributed under the terms of the
 * Q Public License 1.0, which can be found in the file LICENSE.QPL included in
 * the packaging of this file.
 *
 * Alternatively, it may be distributed under the terms of the GNU General
 * Public License, either version 2 or 3, which can be found in the file
 * LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
 * file.
 */

#include "config.h"

#include <string.h>

#import "OFMD5Hash.h"

#import "OFHashAlreadyCalculatedException.h"

#import "macros.h"

/* The four MD5 core functions - F1 is optimized somewhat */
#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))

/* This is the central step in the MD5 algorithm. */
#define MD5STEP(f, w, x, y, z, data, s) \
	(w += f(x, y, z) + data, w = w << s | w >> (32 - s), w += x)

#ifdef OF_BIG_ENDIAN
static OF_INLINE void
BSWAP32_VEC_IF_BE(uint32_t *buffer, size_t length)
{
	while (length--) {
		*buffer = OF_BSWAP32(*buffer);
		buffer++;
	}
}
#else
# define BSWAP32_VEC_IF_BE(buffer, length)
#endif

static void
md5_transform(uint32_t buffer[4], const uint32_t in[16])
{
	register uint32_t a, b, c, d;

	a = buffer[0];
	b = buffer[1];
	c = buffer[2];
	d = buffer[3];

	MD5STEP(F1, a, b, c, d, in[0]  + 0xD76AA478, 7);
	MD5STEP(F1, d, a, b, c, in[1]  + 0xE8C7B756, 12);
	MD5STEP(F1, c, d, a, b, in[2]  + 0x242070DB, 17);
	MD5STEP(F1, b, c, d, a, in[3]  + 0xC1BDCEEE, 22);
	MD5STEP(F1, a, b, c, d, in[4]  + 0xF57C0FAF, 7);
	MD5STEP(F1, d, a, b, c, in[5]  + 0x4787C62A, 12);
	MD5STEP(F1, c, d, a, b, in[6]  + 0xA8304613, 17);
	MD5STEP(F1, b, c, d, a, in[7]  + 0xFD469501, 22);
	MD5STEP(F1, a, b, c, d, in[8]  + 0x698098D8, 7);
	MD5STEP(F1, d, a, b, c, in[9]  + 0x8B44F7AF, 12);
	MD5STEP(F1, c, d, a, b, in[10] + 0xFFFF5BB1, 17);
	MD5STEP(F1, b, c, d, a, in[11] + 0x895CD7Be, 22);
	MD5STEP(F1, a, b, c, d, in[12] + 0x6B901122, 7);
	MD5STEP(F1, d, a, b, c, in[13] + 0xFD987193, 12);
	MD5STEP(F1, c, d, a, b, in[14] + 0xA679438e, 17);
	MD5STEP(F1, b, c, d, a, in[15] + 0x49B40821, 22);

	MD5STEP(F2, a, b, c, d, in[1]  + 0xF61E2562, 5);
	MD5STEP(F2, d, a, b, c, in[6]  + 0xC040B340, 9);
	MD5STEP(F2, c, d, a, b, in[11] + 0x265E5A51, 14);
	MD5STEP(F2, b, c, d, a, in[0]  + 0xE9B6C7AA, 20);
	MD5STEP(F2, a, b, c, d, in[5]  + 0xD62F105D, 5);
	MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
	MD5STEP(F2, c, d, a, b, in[15] + 0xD8A1E681, 14);
	MD5STEP(F2, b, c, d, a, in[4]  + 0xE7D3FBC8, 20);
	MD5STEP(F2, a, b, c, d, in[9]  + 0x21E1CDE6, 5);
	MD5STEP(F2, d, a, b, c, in[14] + 0xC33707D6, 9);
	MD5STEP(F2, c, d, a, b, in[3]  + 0xF4D50D87, 14);
	MD5STEP(F2, b, c, d, a, in[8]  + 0x455A14ED, 20);
	MD5STEP(F2, a, b, c, d, in[13] + 0xA9E3E905, 5);
	MD5STEP(F2, d, a, b, c, in[2]  + 0xFCEFA3F8, 9);
	MD5STEP(F2, c, d, a, b, in[7]  + 0x676F02D9, 14);
	MD5STEP(F2, b, c, d, a, in[12] + 0x8D2A4C8a, 20);

	MD5STEP(F3, a, b, c, d, in[5]  + 0xFFFA3942, 4);
	MD5STEP(F3, d, a, b, c, in[8]  + 0x8771F681, 11);
	MD5STEP(F3, c, d, a, b, in[11] + 0x6D9D6122, 16);
	MD5STEP(F3, b, c, d, a, in[14] + 0xFDE5380c, 23);
	MD5STEP(F3, a, b, c, d, in[1]  + 0xA4BEEA44, 4);
	MD5STEP(F3, d, a, b, c, in[4]  + 0x4BDECFA9, 11);
	MD5STEP(F3, c, d, a, b, in[7]  + 0xF6BB4B60, 16);
	MD5STEP(F3, b, c, d, a, in[10] + 0xBEBFBC70, 23);
	MD5STEP(F3, a, b, c, d, in[13] + 0x289B7EC6, 4);
	MD5STEP(F3, d, a, b, c, in[0]  + 0xEAA127FA, 11);
	MD5STEP(F3, c, d, a, b, in[3]  + 0xD4EF3085, 16);
	MD5STEP(F3, b, c, d, a, in[6]  + 0x04881D05, 23);
	MD5STEP(F3, a, b, c, d, in[9]  + 0xD9D4D039, 4);
	MD5STEP(F3, d, a, b, c, in[12] + 0xE6DB99E5, 11);
	MD5STEP(F3, c, d, a, b, in[15] + 0x1FA27CF8, 16);
	MD5STEP(F3, b, c, d, a, in[2]  + 0xC4AC5665, 23);

	MD5STEP(F4, a, b, c, d, in[0]  + 0xF4292244, 6);
	MD5STEP(F4, d, a, b, c, in[7]  + 0x432AFF97, 10);
	MD5STEP(F4, c, d, a, b, in[14] + 0xAB9423A7, 15);
	MD5STEP(F4, b, c, d, a, in[5]  + 0xFC93A039, 21);
	MD5STEP(F4, a, b, c, d, in[12] + 0x655B59C3, 6);
	MD5STEP(F4, d, a, b, c, in[3]  + 0x8F0CCC92, 10);
	MD5STEP(F4, c, d, a, b, in[10] + 0xFFEFF47d, 15);
	MD5STEP(F4, b, c, d, a, in[1]  + 0x85845DD1, 21);
	MD5STEP(F4, a, b, c, d, in[8]  + 0x6FA87E4F, 6);
	MD5STEP(F4, d, a, b, c, in[15] + 0xFE2CE6E0, 10);
	MD5STEP(F4, c, d, a, b, in[6]  + 0xA3014314, 15);
	MD5STEP(F4, b, c, d, a, in[13] + 0x4E0811A1, 21);
	MD5STEP(F4, a, b, c, d, in[4]  + 0xF7537E82, 6);
	MD5STEP(F4, d, a, b, c, in[11] + 0xBD3AF235, 10);
	MD5STEP(F4, c, d, a, b, in[2]  + 0x2AD7D2BB, 15);
	MD5STEP(F4, b, c, d, a, in[9]  + 0xEB86D391, 21);

	buffer[0] += a;
	buffer[1] += b;
	buffer[2] += c;
	buffer[3] += d;
}

@implementation OFMD5Hash
+ (size_t)digestSize
{
	return 16;
}

+ (size_t)blockSize
{
	return 64;
}

+ (instancetype)hash
{
	return [[[self alloc] init] autorelease];
}

- init
{
	self = [super init];

	_buffer[0] = 0x67452301;
	_buffer[1] = 0xEFCDAB89;
	_buffer[2] = 0x98BADCFE;
	_buffer[3] = 0x10325476;

	return self;
}

- (void)updateWithBuffer: (const void*)buffer_
		  length: (size_t)length
{
	uint32_t t;
	const char *buffer = buffer_;

	if (length == 0)
		return;

	if (_calculated)
		@throw [OFHashAlreadyCalculatedException
		    exceptionWithHash: self];

	/* Update bitcount */
	t = _bits[0];
	if ((_bits[0] = t + ((uint32_t)length << 3)) < t)
		/* Carry from low to high */
		_bits[1]++;
	_bits[1] += (uint32_t)length >> 29;

	/* Bytes already in shsInfo->data */
	t = (t >> 3) & 0x3F;

	/* Handle any leading odd-sized chunks */
	if (t) {
		uint8_t *p = _in.u8 + t;

		t = 64 - t;

		if (length < t) {
			memcpy(p, buffer, length);
			return;
		}

		memcpy(p, buffer, t);
		BSWAP32_VEC_IF_BE(_in.u32, 16);
		md5_transform(_buffer, _in.u32);

		buffer += t;
		length -= t;
	}

	/* Process data in 64-byte chunks */
	while (length >= 64) {
		memcpy(_in.u8, buffer, 64);
		BSWAP32_VEC_IF_BE(_in.u32, 16);
		md5_transform(_buffer, _in.u32);

		buffer += 64;
		length -= 64;
	}

	/* Handle any remaining bytes of data. */
	memcpy(_in.u8, buffer, length);
}

- (uint8_t*)digest
{
	uint8_t	*p;
	size_t count;

	if (_calculated)
		return (uint8_t*)_buffer;

	/* Compute number of bytes mod 64 */
	count = (_bits[0] >> 3) & 0x3F;

	/*
	 * Set the first char of padding to 0x80. This is safe since there is
	 * always at least one byte free
	 */
	p = _in.u8 + count;
	*p++ = 0x80;

	/* Bytes of padding needed to make 64 bytes */
	count = 64 - 1 - count;

	/* Pad out to 56 mod 64 */
	if (count < 8) {
		/* Two lots of padding: Pad the first block to 64 bytes */
		memset(p, 0, count);
		BSWAP32_VEC_IF_BE(_in.u32, 16);
		md5_transform(_buffer, _in.u32);

		/* Now fill the next block with 56 bytes */
		memset(_in.u8, 0, 56);
	} else {
		/* Pad block to 56 bytes */
		memset(p, 0, count - 8);
	}
	BSWAP32_VEC_IF_BE(_in.u32, 14);

	/* Append length in bits and transform */
	_in.u32[14] = _bits[0];
	_in.u32[15] = _bits[1];

	md5_transform(_buffer, _in.u32);
	BSWAP32_VEC_IF_BE(_buffer, 4);

	_calculated = true;

	return (uint8_t*)_buffer;
}

- (bool)isCalculated
{
	return _calculated;
}
@end