ObjXMPP  Diff

/*
 * Copyright (c) 2011, Florian Zeitz <florob@babelmonkeys.de>
 * Copyright (c) 2011, Jonathan Schleifer <js@webkeks.org>
 *
 * https://heap.zone/objxmpp/
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice is present in all copies.
 *

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

		_authzid = [new retain];
	} 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"];

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

	[old release];
}

- (OFData *)initialMessage

	_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]];

	[ret makeImmutable];

	return ret;
}

- (OFData *)continueWithData: (OFData *)data

		GOT_ITERCOUNT = 0x04
	} got = 0;

	hash = [[[_hashType alloc] init] autorelease];
	ret = [OFMutableData data];
	authMessage = [OFMutableData data];

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

	for (OFString *component in
	    [challenge componentsSeparatedByString: @","]) {
		OFString *entry = [component substringWithRange:
		    of_range(2, [component length] - 2)];

		if ([component hasPrefix: @"r="]) {
			if (![entry hasPrefix: _cNonce])
				@throw [XMPPAuthFailedException
				    exceptionWithConnection: nil
						     reason: @"Received wrong "
							     @"nonce"];

			sNonce = entry;
			got |= GOT_SNONCE;
		} else if ([component hasPrefix: @"s="]) {
			salt = [OFData dataWithBase64EncodedString: entry];
			got |= GOT_SALT;
		} else if ([component 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 = [OFMutableData dataWithItems: [_GS2Header UTF8String]
					  count: [_GS2Header UTF8StringLength]];
	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"

			length: [_hashType digestSize]];

	/*
	 * IETF RFC 5802:
	 * ClientSignature := HMAC(StoredKey, AuthMessage)
	 */
	clientSignature = [self
	    xmpp_HMACWithKey: [OFData dataWithItems: [hash digest]
					      count: [_hashType digestSize]]
			data: authMessage];

	/*
	 * IETF RFC 5802:
	 * ServerKey := HMAC(SaltedPassword, "Server Key")
	 */
	serverKey = [self xmpp_HMACWithKey: saltedPassword

		[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;

	/*
	 * 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 "
						     @"ServerSignature"];
		_authenticated = true;
	} else
		@throw [XMPPAuthFailedException exceptionWithConnection: nil

{
	void *pool = objc_autoreleasePoolPush();
	OFMutableData *k = [OFMutableData data];
	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]
				length: [key itemSize] * [key count]];
		[k addItems: [hashI digest]
		      count: [_hashType digestSize]];
	} else
		[k addItems: [key items]
		      count: [key itemSize] * [key count]];

	@try {
		kI = [self allocMemoryWithSize: blockSize];
		kO = [self allocMemoryWithSize: blockSize];

		kSize = [k count];
		memcpy(kI, [k items], kSize);
		memset(kI + kSize, 0, blockSize - kSize);
		memcpy(kO, kI, blockSize);

		for (i = 0; i < blockSize; i++) {
			kI[i] ^= HMAC_IPAD;
			kO[i] ^= HMAC_OPAD;
		}

		hashI = [[[_hashType alloc] init] autorelease];
		[hashI updateWithBuffer: (char *)kI
				 length: blockSize];
		[hashI updateWithBuffer: [data items]
				 length: [data itemSize] * [data count]];

		hashO = [[[_hashType alloc] init] autorelease];
		[hashO updateWithBuffer: (char *)kO
				 length: blockSize];
		[hashO updateWithBuffer: (char *)[hashI digest]
				 length: [_hashType digestSize]];
	} @finally {
		[self freeMemory: kI];
		[self freeMemory: kO];
	}

	[hashO retain];