ObjFW  Check-in [0e57691b22]

 * LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
 * file.
 */

#include "config.h"

#import "OFHMAC.h"
#import "OFSecureData.h"

#import "OFHashAlreadyCalculatedException.h"
#import "OFInvalidArgumentException.h"

@implementation OFHMAC
@synthesize hashClass = _hashClass;

}

- (void)setKey: (const void *)key
	length: (size_t)length
{
	void *pool = objc_autoreleasePoolPush();
	size_t blockSize = [_hashClass blockSize];
	OFSecureData *outerKeyPad = [OFSecureData dataWithCount: blockSize];
	OFSecureData *innerKeyPad = [OFSecureData dataWithCount: blockSize];
	uint8_t outerKeyPad[blockSize], innerKeyPad[blockSize];
	unsigned char *outerKeyPadItems = [outerKeyPad items];
	unsigned char *innerKeyPadItems = [innerKeyPad items];

	[_outerHash release];
	[_innerHash release];
	[_outerHashCopy release];
	[_innerHashCopy release];
	_outerHash = _innerHash = _outerHashCopy = _innerHashCopy = nil;

	@try {
	if (length > blockSize) {
		id <OFCryptoHash> hash = [_hashClass cryptoHash];

		[hash updateWithBuffer: key
				length: length];

		length = [_hashClass digestSize];
		if OF_UNLIKELY (length > blockSize)
			length = blockSize;

		memcpy(outerKeyPad, [hash digest], length);
		memcpy(innerKeyPad, [hash digest], length);
			memcpy(outerKeyPadItems, [hash digest], length);
			memcpy(innerKeyPadItems, [hash digest], length);
	} else {
		memcpy(outerKeyPad, key, length);
		memcpy(innerKeyPad, key, length);
			memcpy(outerKeyPadItems, key, length);
			memcpy(innerKeyPadItems, key, length);
	}

	memset(outerKeyPad + length, 0, blockSize - length);
	memset(innerKeyPad + length, 0, blockSize - length);
		memset(outerKeyPadItems + length, 0, blockSize - length);
		memset(innerKeyPadItems + length, 0, blockSize - length);

	for (size_t i = 0; i < blockSize; i++) {
		outerKeyPad[i] ^= 0x5C;
		innerKeyPad[i] ^= 0x36;
			outerKeyPadItems[i] ^= 0x5C;
			innerKeyPadItems[i] ^= 0x36;
	}

	_outerHash = [[_hashClass cryptoHash] retain];
	_innerHash = [[_hashClass cryptoHash] retain];

	[_outerHash updateWithBuffer: outerKeyPad
		[_outerHash updateWithBuffer: outerKeyPadItems
			      length: blockSize];
	[_innerHash updateWithBuffer: innerKeyPad
		[_innerHash updateWithBuffer: innerKeyPadItems
			      length: blockSize];
	} @catch (id e) {
		[outerKeyPad zero];
		[innerKeyPad zero];
	}

	objc_autoreleasePoolPop(pool);

	_outerHashCopy = [_outerHash copy];
	_innerHashCopy = [_innerHash copy];

	_calculated = false;