ObjXMPP  Diff

#import "XMPPExceptions.h"

#define HMAC_IPAD 0x36
#define HMAC_OPAD 0x5c

@interface XMPPSCRAMAuth ()
- (OFString *)xmpp_genNonce;
- (const uint8_t *)xmpp_HMACWithKey: (OFData *)key
			       data: (OFData *)data;
- (OFData *)xmpp_hiWithData: (OFData *)str
		       salt: (OFData *)salt
	     iterationCount: (intmax_t)i;
- (OFData *)xmpp_parseServerFirstMessage: (OFData *)data;
- (OFData *)xmpp_parseServerFinalMessage: (OFData *)data;
@end

- (void)setAuthzid: (OFString *)authzid
{
	OFString *old = _authzid;

	if (authzid) {
		OFMutableString *new = [[authzid mutableCopy] autorelease];
		[new replaceOccurrencesOfString: @"="
				     withString: @"=3D"];
		[new replaceOccurrencesOfString: @","
				     withString: @"=2C"];
		[new makeImmutable];
		_authzid = [new copy];
	} else
		_authzid = nil;

	[old release];
}

- (void)setAuthcid: (OFString *)authcid
{
	OFString *old = _authcid;

	if (authcid) {
		OFMutableString *new = [[authcid mutableCopy] autorelease];
		[new replaceOccurrencesOfString: @"="
				     withString: @"=3D"];
		[new replaceOccurrencesOfString: @","
				     withString: @"=2C"];
		[new makeImmutable];
		_authcid = [new copy];
	} else
		_authcid = nil;

	[old release];
}

	if (_plusAvailable && _connection.encrypted) {
		OFData *channelBinding = [((SSLSocket *)[_connection socket])
		    channelBindingDataWithType: @"tls-unique"];
		[tmpArray addItems: channelBinding.items
			     count: channelBinding.count];
	}
	tmpString = tmpArray.stringByBase64Encoding;
	[ret addItems: "c="
		count: 2];
	[ret addItems: tmpString.UTF8String
		count: tmpString.UTF8StringLength];

	// Add r=<nonce>
	[ret addItem: ","];
	[ret addItems: "r="
		count: 2];
	[ret addItems: sNonce.UTF8String
		count: sNonce.UTF8StringLength];

	/*
	 * IETF RFC 5802:
	 * SaltedPassword := Hi(Normalize(password), salt, i)
	 */
	tmpArray = [OFMutableData dataWithItems: _password.UTF8String
					  count: _password.UTF8StringLength];
	saltedPassword = [self xmpp_hiWithData: tmpArray
					  salt: salt
				iterationCount: iterCount];

	/*
	 * IETF RFC 5802:
	 * AuthMessage := client-first-message-bare + "," +
	 *		  server-first-message + "," +
	 *		  client-final-message-without-proof
	 */
	[authMessage addItems: _clientFirstMessageBare.UTF8String
			count: _clientFirstMessageBare.UTF8StringLength];
	[authMessage addItem: ","];
	[authMessage addItems: data.items
			count: data.count * data.itemSize];
	[authMessage addItem: ","];
	[authMessage addItems: ret.items
			count: ret.count];

	/*
	 * IETF RFC 5802:
	 * ClientKey := HMAC(SaltedPassword, "Client Key")
	 */

	clientKey = [self xmpp_HMACWithKey: saltedPassword
				      data: [OFData dataWithItems: "Client Key"
							    count: 10]];

	/*
	 * IETF RFC 5802:
	 * StoredKey := H(ClientKey)
	 */
	[hash updateWithBuffer: (void *)clientKey
			length: [_hashType digestSize]];

					      count: hash.digestSize]
			data: authMessage];

	/*
	 * IETF RFC 5802:
	 * ServerKey := HMAC(SaltedPassword, "Server Key")
	 */

	serverKey = [self xmpp_HMACWithKey: saltedPassword
				      data: [OFData dataWithItems: "Server Key"
							    count: 10]];

	/*
	 * IETF RFC 5802:
	 * ServerSignature := HMAC(ServerKey, AuthMessage)
	 */
	tmpArray = [OFMutableData dataWithItems: serverKey
					  count: [_hashType digestSize]];

	[_serverSignature release];
	_serverSignature = [[OFData alloc]
	    initWithItems: [self xmpp_HMACWithKey: tmpArray
					     data: authMessage]
		    count: [_hashType digestSize]];

	/*
	 * IETF RFC 5802:
	 * ClientProof := ClientKey XOR ClientSignature
	 */
	tmpArray = [OFMutableData dataWithCapacity: [_hashType digestSize]];
	for (i = 0; i < [_hashType digestSize]; i++) {
		uint8_t c = clientKey[i] ^ clientSignature[i];
		[tmpArray addItem: &c];
	}

	// Add p=<base64(ClientProof)>
	[ret addItem: ","];
	[ret addItems: "p="
		count: 2];
	tmpString = tmpArray.stringByBase64Encoding;
	[ret addItems: tmpString.UTF8String
		count: tmpString.UTF8StringLength];

	return ret;
}

- (OFData *)xmpp_parseServerFinalMessage: (OFData *)data
{
	OFString *mess, *value;

	uint8_t *kI = NULL, *kO = NULL;
	id <OFCryptographicHash> hashI, hashO;

	if (key.itemSize * key.count > blockSize) {
		hashI = [[[_hashType alloc] init] autorelease];
		[hashI updateWithBuffer: key.items
				 length: key.itemSize * key.count];
		[k addItems: hashI.digest
		      count: hashI.digestSize];
	} else
		[k addItems: key.items
		      count: key.itemSize * key.count];

	@try {
		kI = OFAllocMemory(1, blockSize);
		kO = OFAllocMemory(1, blockSize);

		kSize = k.count;
		memcpy(kI, k.items, kSize);

	@try {
		memset(result, 0, digestSize);

		salty = [[salt mutableCopy] autorelease];
		[salty addItems: "\0\0\0\1"
			  count: 4];

		uOld = [self xmpp_HMACWithKey: str
					 data: salty];

		for (j = 0; j < digestSize; j++)
			result[j] ^= uOld[j];

		for (j = 0; j < i - 1; j++) {
			tmp = [[OFMutableData alloc] init];
			[tmp addItems: uOld
				count: digestSize];

			/* releases uOld and previous tmp */
			objc_autoreleasePoolPop(pool);
			pool = objc_autoreleasePoolPush();
			[tmp autorelease];

			u = [self xmpp_HMACWithKey: str
					      data: tmp];

			for (k = 0; k < digestSize; k++)
				result[k] ^= u[k];

			uOld = u;
		}

		ret = [OFData dataWithItems: result
				      count: digestSize];
	} @finally {
		OFFreeMemory(result);
	}

	[ret retain];

	objc_autoreleasePoolPop(pool);

	return [ret autorelease];
}
@end