ObjFW  Artifact [8c5830ca8e]

Artifact 8c5830ca8e66850d8bb7cd69488a383f085fa76d11198b1d672e57abbe2b0766:

• File src/OFSHA1Hash.m — part of check-in [e1e7ffa903] at 2011-09-22 23:25:42 on branch trunk — Exceptions are now autoreleased.

  This is safe as an "exception loop" can't happen, since if allocating
  an exception fails, it throws an OFAllocFailedException which is
  preallocated and can always be thrown.

  So, the worst case would be that an autorelease of an exception fails,
  triggering an OFOutOfMemoryException for which there is no memory,
  resulting in an OFAllocFailedException to be thrown. (user: js, size: 5358) [annotate] [blame] [check-ins using]

/*
 * Copyright (c) 2008, 2009, 2010, 2011
 *   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 "OFSHA1Hash.h"

#import "OFHashAlreadyCalculatedException.h"

#import "macros.h"

/* blk0() and blk() perform the initial expand. */
#ifndef OF_BIG_ENDIAN
#define blk0(i)							\
	(block.l[i] = (OF_ROL(block.l[i], 24) & 0xFF00FF00) |	\
	    (OF_ROL(block.l[i], 8) & 0x00FF00FF))
#else
#define blk0(i) block.l[i]
#endif
#define blk(i) \
	(block.l[i & 15] = OF_ROL(block.l[(i + 13) & 15] ^	\
	    block.l[(i + 8) & 15] ^ block.l[(i + 2) & 15] ^	\
	    block.l[i & 15], 1))

/* (R0+R1), R2, R3, R4 are the different operations used in SHA1 */
#define R0(v, w, x, y, z, i)						\
	z += ((w & (x ^ y)) ^ y) + blk0(i) + 0x5A827999 + OF_ROL(v, 5);	\
	w = OF_ROL(w, 30);
#define R1(v, w, x, y, z, i)						\
	z += ((w & (x ^ y)) ^ y) + blk(i) +  0x5A827999 + OF_ROL(v, 5);	\
	w = OF_ROL(w, 30);
#define R2(v, w, x, y, z, i)						\
	z += (w ^ x ^ y) + blk(i) + 0x6ED9EBA1 + OF_ROL(v, 5);		\
	w = OF_ROL(w, 30);
#define R3(v, w, x, y, z, i)						     \
	z += (((w | x) & y) | (w & x)) + blk(i) + 0x8F1BBCDC + OF_ROL(v, 5); \
	w = OF_ROL(w, 30);
#define R4(v, w, x, y, z, i)						\
	z += (w ^ x ^ y) + blk(i) + 0xCA62C1D6 + OF_ROL(v, 5);		\
	w = OF_ROL(w, 30);

typedef union {
	char	 c[64];
	uint32_t l[16];
} sha1_c64l16_t;

static inline void
sha1_transform(uint32_t state[5], const char buffer[64])
{
	uint32_t      a, b, c, d, e;
	sha1_c64l16_t block;

	memcpy(block.c, buffer, 64);

	/* Copy state[] to working vars */
	a = state[0];
	b = state[1];
	c = state[2];
	d = state[3];
	e = state[4];

	/* 4 rounds of 20 operations each. Loop unrolled. */
	R0(a,b,c,d,e, 0); R0(e,a,b,c,d, 1); R0(d,e,a,b,c, 2); R0(c,d,e,a,b, 3);
	R0(b,c,d,e,a, 4); R0(a,b,c,d,e, 5); R0(e,a,b,c,d, 6); R0(d,e,a,b,c, 7);
	R0(c,d,e,a,b, 8); R0(b,c,d,e,a, 9); R0(a,b,c,d,e,10); R0(e,a,b,c,d,11);
	R0(d,e,a,b,c,12); R0(c,d,e,a,b,13); R0(b,c,d,e,a,14); R0(a,b,c,d,e,15);
	R1(e,a,b,c,d,16); R1(d,e,a,b,c,17); R1(c,d,e,a,b,18); R1(b,c,d,e,a,19);
	R2(a,b,c,d,e,20); R2(e,a,b,c,d,21); R2(d,e,a,b,c,22); R2(c,d,e,a,b,23);
	R2(b,c,d,e,a,24); R2(a,b,c,d,e,25); R2(e,a,b,c,d,26); R2(d,e,a,b,c,27);
	R2(c,d,e,a,b,28); R2(b,c,d,e,a,29); R2(a,b,c,d,e,30); R2(e,a,b,c,d,31);
	R2(d,e,a,b,c,32); R2(c,d,e,a,b,33); R2(b,c,d,e,a,34); R2(a,b,c,d,e,35);
	R2(e,a,b,c,d,36); R2(d,e,a,b,c,37); R2(c,d,e,a,b,38); R2(b,c,d,e,a,39);
	R3(a,b,c,d,e,40); R3(e,a,b,c,d,41); R3(d,e,a,b,c,42); R3(c,d,e,a,b,43);
	R3(b,c,d,e,a,44); R3(a,b,c,d,e,45); R3(e,a,b,c,d,46); R3(d,e,a,b,c,47);
	R3(c,d,e,a,b,48); R3(b,c,d,e,a,49); R3(a,b,c,d,e,50); R3(e,a,b,c,d,51);
	R3(d,e,a,b,c,52); R3(c,d,e,a,b,53); R3(b,c,d,e,a,54); R3(a,b,c,d,e,55);
	R3(e,a,b,c,d,56); R3(d,e,a,b,c,57); R3(c,d,e,a,b,58); R3(b,c,d,e,a,59);
	R4(a,b,c,d,e,60); R4(e,a,b,c,d,61); R4(d,e,a,b,c,62); R4(c,d,e,a,b,63);
	R4(b,c,d,e,a,64); R4(a,b,c,d,e,65); R4(e,a,b,c,d,66); R4(d,e,a,b,c,67);
	R4(c,d,e,a,b,68); R4(b,c,d,e,a,69); R4(a,b,c,d,e,70); R4(e,a,b,c,d,71);
	R4(d,e,a,b,c,72); R4(c,d,e,a,b,73); R4(b,c,d,e,a,74); R4(a,b,c,d,e,75);
	R4(e,a,b,c,d,76); R4(d,e,a,b,c,77); R4(c,d,e,a,b,78); R4(b,c,d,e,a,79);

	/* Add the working vars back into state[] */
	state[0] += a;
	state[1] += b;
	state[2] += c;
	state[3] += d;
	state[4] += e;
}

static inline void
sha1_update(uint32_t *state, uint64_t *count, char *buffer,
    const char *buf, size_t length)
{
	size_t i, j;

	j = (size_t)((*count >> 3) & 63);
	*count += (length << 3);

	if ((j + length) > 63) {
		memcpy(&buffer[j], buf, (i = 64 - j));

		sha1_transform(state, buffer);

		for (; i + 63 < length; i += 64)
			sha1_transform(state, &buf[i]);

		j = 0;
	} else
		i = 0;

	memcpy(&buffer[j], &buf[i], length - i);
}

@implementation OFSHA1Hash
+ SHA1Hash
{
	return [[[self alloc] init] autorelease];
}

+ (size_t)digestSize
{
	return 20;
}

+ (size_t)blockSize
{
	return 64;
}

- init
{
	self = [super init];

	state[0] = 0x67452301;
	state[1] = 0xEFCDAB89;
	state[2] = 0x98BADCFE;
	state[3] = 0x10325476;
	state[4] = 0xC3D2E1F0;

	return self;
}

- (void)updateWithBuffer: (const char*)buffer_
		  length: (size_t)length
{
	if (length == 0)
		return;

	if (calculated)
		@throw [OFHashAlreadyCalculatedException
		    exceptionWithClass: isa
				  hash: self];

	sha1_update(state, &count, buffer, buffer_, length);
}

- (uint8_t*)digest
{
	size_t i;
	char   finalcount[8];

	if (calculated)
		return digest;

	for (i = 0; i < 8; i++)
		/* Endian independent */
		finalcount[i] = (char)((count >> ((7 - (i & 7)) * 8)) & 255);
	sha1_update(state, &count, buffer, "\200", 1);

	while ((count & 504) != 448)
		sha1_update(state, &count, buffer, "\0", 1);
	/* Should cause a sha1_transform() */
	sha1_update(state, &count, buffer, finalcount, 8);

	for (i = 0; i < OF_SHA1_DIGEST_SIZE; i++)
		digest[i] = (char)((state[i >> 2] >>
		    ((3 - (i & 3)) * 8)) & 255);

	calculated = YES;

	return digest;
}
@end