ObjXMPP  Diff

#define HMAC_IPAD 0x36
#define HMAC_OPAD 0x5c

OF_ASSUME_NONNULL_BEGIN

@interface XMPPSCRAMAuth ()
- (OFString *)XMPP_genNonce;
- (const uint8_t *)XMPP_HMACWithKey: (OFDataArray *)key
			data: (OFDataArray *)data;
- (OFDataArray *)XMPP_hiWithData: (OFDataArray *)str
			   salt: (OFDataArray *)salt
		 iterationCount: (intmax_t)i;
- (OFDataArray *)XMPP_parseServerFirstMessage: (OFDataArray *)data;
- (OFDataArray *)XMPP_parseServerFinalMessage: (OFDataArray *)data;
@end

OF_ASSUME_NONNULL_END

@implementation XMPPSCRAMAuth
+ (instancetype)SCRAMAuthWithAuthcid: (OFString *)authcid
			    password: (OFString *)password

		_authcid = [new retain];
	} else
		_authcid = nil;

	[old release];
}

- (OFDataArray *)initialMessage
{
	OFDataArray *ret = [OFDataArray dataArray];

	/* New authentication attempt, reset status */
	[_cNonce release];
	_cNonce = nil;
	[_GS2Header release];
	_GS2Header = nil;
	[_serverSignature release];
	_serverSignature = nil;
	_authenticated = false;

	if (_authzid)
		_GS2Header = [[OFString alloc]
		    initWithFormat: @"%@,a=%@,",
				    (_plusAvailable ? @"p=tls-unique" : @"y"),
				    _authzid];
	else
		_GS2Header = (_plusAvailable ? @"p=tls-unique,," : @"y,,");

	_cNonce = [[self XMPP_genNonce] retain];

	[_clientFirstMessageBare release];
	_clientFirstMessageBare = nil;
	_clientFirstMessageBare = [[OFString alloc]
	    initWithFormat: @"n=%@,r=%@", _authcid, _cNonce];

	[ret addItems: [_GS2Header UTF8String]
		count: [_GS2Header UTF8StringLength]];

	[ret addItems: [_clientFirstMessageBare UTF8String]
		count: [_clientFirstMessageBare UTF8StringLength]];



	return ret;
}

- (OFDataArray *)continueWithData: (OFDataArray *)data
{
	OFAutoreleasePool *pool = [[OFAutoreleasePool alloc] init];
	OFDataArray *ret;

	if (!_serverSignature)
		ret = [self XMPP_parseServerFirstMessage: data];
	else
		ret = [self XMPP_parseServerFinalMessage: data];

	[ret retain];
	[pool release];

	return [ret autorelease];
}

- (OFDataArray *)XMPP_parseServerFirstMessage: (OFDataArray *)data
{
	size_t i;
	const uint8_t *clientKey, *serverKey, *clientSignature;
	intmax_t iterCount = 0;
	id <OFCryptoHash> hash;

	OFDataArray *ret, *authMessage, *tmpArray, *salt = nil, *saltedPassword;
	OFString *tmpString, *sNonce = nil;
	OFEnumerator *enumerator;
	OFString *comp;
	enum {
		GOT_SNONCE    = 0x01,
		GOT_SALT      = 0x02,
		GOT_ITERCOUNT = 0x04
	} got = 0;

	hash = [[[_hashType alloc] init] autorelease];
	ret = [OFDataArray dataArray];
	authMessage = [OFDataArray dataArray];

	OFString *chal = [OFString stringWithUTF8String: [data items]
						 length: [data count] *
							 [data itemSize]];

	enumerator =
	    [[chal componentsSeparatedByString: @","] objectEnumerator];

				    exceptionWithConnection: nil
						     reason: @"Received wrong "
							     @"nonce"];

			sNonce = entry;
			got |= GOT_SNONCE;
		} else if ([comp hasPrefix: @"s="]) {
			salt = [OFDataArray
			    dataArrayWithBase64EncodedString: entry];
			got |= GOT_SALT;
		} else if ([comp hasPrefix: @"i="]) {
			iterCount = [entry decimalValue];
			got |= GOT_ITERCOUNT;
		}
	}

	if (got != (GOT_SNONCE | GOT_SALT | GOT_ITERCOUNT))
		@throw [OFInvalidServerReplyException exception];

	// Add c=<base64(GS2Header+channelBindingData)>
	tmpArray = [OFDataArray dataArray];
	[tmpArray addItems: [_GS2Header UTF8String]
		     count: [_GS2Header UTF8StringLength]];
	if (_plusAvailable && [_connection encrypted]) {
		OFDataArray *channelBinding =
		    [((SSLSocket *)[_connection socket])
		    channelBindingDataWithType: @"tls-unique"];
		[tmpArray addItems: [channelBinding items]
			     count: [channelBinding count]];
	}
	tmpString = [tmpArray stringByBase64Encoding];
	[ret addItems: "c="
		count: 2];

	[ret addItems: [sNonce UTF8String]
		count: [sNonce UTF8StringLength]];

	/*
	 * IETF RFC 5802:
	 * SaltedPassword := Hi(Normalize(password), salt, i)
	 */
	tmpArray = [OFDataArray dataArray];
	[tmpArray addItems: [_password UTF8String]
		     count: [_password UTF8StringLength]];

	saltedPassword = [self XMPP_hiWithData: tmpArray
					  salt: salt
				iterationCount: iterCount];

	/*
	 * IETF RFC 5802:
	 * AuthMessage := client-first-message-bare + "," +

	[authMessage addItems: [ret items]
			count: [ret count]];

	/*
	 * IETF RFC 5802:
	 * ClientKey := HMAC(SaltedPassword, "Client Key")
	 */
	tmpArray = [OFDataArray dataArray];
	[tmpArray addItems: "Client Key"
		     count: 10];
	clientKey = [self XMPP_HMACWithKey: saltedPassword
				      data: tmpArray];


	/*
	 * IETF RFC 5802:
	 * StoredKey := H(ClientKey)
	 */
	[hash updateWithBuffer: (void *)clientKey
			length: [_hashType digestSize]];
	tmpArray = [OFDataArray dataArray];
	[tmpArray addItems: [hash digest]
		     count: [_hashType digestSize]];

	/*
	 * IETF RFC 5802:
	 * ClientSignature := HMAC(StoredKey, AuthMessage)
	 */
	clientSignature = [self XMPP_HMACWithKey: tmpArray
					    data: authMessage];

	/*
	 * IETF RFC 5802:
	 * ServerKey := HMAC(SaltedPassword, "Server Key")
	 */
	tmpArray = [OFDataArray dataArray];
	[tmpArray addItems: "Server Key"
		     count: 10];
	serverKey = [self XMPP_HMACWithKey: saltedPassword
				      data: tmpArray];

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


	_serverSignature = [[OFDataArray alloc] init];
	[_serverSignature addItems: [self XMPP_HMACWithKey: tmpArray
						     data: authMessage]
			    count: [_hashType digestSize]];

	/*
	 * IETF RFC 5802:
	 * ClientProof := ClientKey XOR ClientSignature
	 */
	tmpArray = [OFDataArray dataArray];
	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;
}

- (OFDataArray *)XMPP_parseServerFinalMessage: (OFDataArray *)data
{
	OFString *mess, *value;

	/*
	 * server-final-message already received,
	 * we were just waiting for the last word from the server
	 */
	if (_authenticated)
		return nil;

	mess = [OFString stringWithUTF8String: [data items]
				       length: [data count] *
					       [data itemSize]];
	value = [mess substringWithRange: of_range(2, [mess length] - 2)];

	if ([mess hasPrefix: @"v="]) {
		if (![value isEqual: [_serverSignature stringByBase64Encoding]])
			@throw [XMPPAuthFailedException
			    exceptionWithConnection: nil
					     reason: @"Received wrong "

	}

	return [OFString stringWithCString: (char *)buf
				  encoding: OF_STRING_ENCODING_ASCII
				    length: 64];
}

- (const uint8_t *)XMPP_HMACWithKey: (OFDataArray *)key
			       data: (OFDataArray *)data
{
	OFAutoreleasePool *pool = [[OFAutoreleasePool alloc] init];
	OFDataArray *k = [OFDataArray dataArray];
	size_t i, kSize, blockSize = [_hashType blockSize];
	uint8_t *kI = NULL, *kO = NULL;
	id <OFCryptoHash> hashI, hashO;

	if ([key itemSize] * [key count] > blockSize) {
		hashI = [[[_hashType alloc] init] autorelease];
		[hashI updateWithBuffer: [key items]

	[hashO retain];
	[pool release];

	return [[hashO autorelease] digest];
}

- (OFDataArray *)XMPP_hiWithData: (OFDataArray *)str
			    salt: (OFDataArray *)salt
		  iterationCount: (intmax_t)i
{
	OFAutoreleasePool *pool = [[OFAutoreleasePool alloc] init];
	size_t digestSize = [_hashType digestSize];
	uint8_t *result = NULL;
	const uint8_t *u, *uOld;
	intmax_t j, k;
	OFDataArray *salty, *tmp, *ret;

	result = [self allocMemoryWithSize: digestSize];

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

		salty = [[salt copy] 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 = [[OFDataArray alloc] init];
			[tmp addItems: uOld
				count: digestSize];

			[pool releaseObjects]; // releases uOld and previous tmp
			[tmp autorelease];

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

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

			uOld = u;
		}

		ret = [OFDataArray dataArray];
		[ret addItems: result
			count: digestSize];
	} @finally {
		[self freeMemory: result];
	}

	[ret retain];
	[pool release];

	return [ret autorelease];
}
@end