Index: src/Makefile
==================================================================
--- src/Makefile
+++ src/Makefile
@@ -106,10 +106,11 @@
        OFXMLParser.m			\
        OFXMLProcessingInstructions.m	\
        OFZIPArchive.m			\
        OFZIPArchiveEntry.m		\
        base64.m				\
+       crc16.m				\
        crc32.m				\
        huffman_tree.m			\
        of_asprintf.m			\
        of_strptime.m			\
        pbkdf2.m				\

Index: src/OFLHAArchive.m
==================================================================
--- src/OFLHAArchive.m
+++ src/OFLHAArchive.m
@@ -27,12 +27,14 @@
 #endif
 #import "OFStream.h"
 #import "OFSeekableStream.h"
 #import "OFString.h"
 
+#import "crc16.h"
 #import "huffman_tree.h"
 
+#import "OFChecksumFailedException.h"
 #import "OFInvalidArgumentException.h"
 #import "OFInvalidFormatException.h"
 #import "OFNotImplementedException.h"
 #import "OFNotOpenException.h"
 #import "OFTruncatedDataException.h"
@@ -69,10 +71,11 @@
 
 @interface OFLHAArchive_FileReadStream: OFStream <OFReadyForReadingObserving>
 {
 	OF_KINDOF(OFStream *) _stream;
 	uint32_t _toRead;
+	uint16_t _expectedCRC16, _CRC16;
 	bool _atEndOfStream;
 }
 
 - (instancetype)of_initWithStream: (OFStream *)stream
 			    entry: (OFLHAArchiveEntry *)entry;
@@ -726,10 +729,12 @@
 		    [method isEqual: @"-lz4-"] || [method isEqual: @"-lh5-"] ||
 		    [method isEqual: @"-lh6-"] || [method isEqual: @"-lh6-"])
 			_toRead = [entry uncompressedSize];
 		else
 			_toRead = [entry compressedSize];
+
+		_expectedCRC16 = [entry CRC16];
 	} @catch (id e) {
 		[self release];
 		@throw e;
 	}
 
@@ -759,13 +764,18 @@
 
 	ret = [_stream readIntoBuffer: buffer
 			       length: length];
 
 	_toRead -= ret;
+	_CRC16 = of_crc16(_CRC16, buffer, ret);
 
-	if (_toRead == 0)
+	if (_toRead == 0) {
 		_atEndOfStream = true;
+
+		if (_CRC16 != _expectedCRC16)
+			@throw [OFChecksumFailedException exception];
+	}
 
 	return ret;
 }
 
 - (bool)lowlevelIsAtEndOfStream

Index: src/ObjFW.h
==================================================================
--- src/ObjFW.h
+++ src/ObjFW.h
@@ -220,15 +220,17 @@
 # import "OFRecursiveMutex.h"
 # import "OFCondition.h"
 #endif
 
 #import "base64.h"
+#import "crc16.h"
 #import "crc32.h"
+#import "huffman_tree.h"
 #import "instance.h"
 #import "of_asprintf.h"
 #import "of_strptime.h"
 #ifdef OF_HAVE_SOCKETS
 # import "resolver.h"
 #endif
 #import "pbkdf2.h"
 #import "scrypt.h"
 #import "unicode.h"

ADDED   src/crc16.h
Index: src/crc16.h
==================================================================
--- src/crc16.h
+++ src/crc16.h
@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017,
+ *               2018
+ *   Jonathan Schleifer <js@heap.zone>
+ *
+ * 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.
+ */
+
+#ifndef __STDC_LIMIT_MACROS
+# define __STDC_LIMIT_MACROS
+#endif
+#ifndef __STDC_CONSTANT_MACROS
+# define __STDC_CONSTANT_MACROS
+#endif
+
+#import "macros.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+extern uint16_t of_crc16(uint16_t crc, const unsigned char *_Nonnull bytes,
+    size_t length);
+#ifdef __cplusplus
+}
+#endif

ADDED   src/crc16.m
Index: src/crc16.m
==================================================================
--- src/crc16.m
+++ src/crc16.m
@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017,
+ *               2018
+ *   Jonathan Schleifer <js@heap.zone>
+ *
+ * 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"
+
+#import "crc32.h"
+
+#define CRC16_MAGIC 0xA001
+
+uint16_t
+of_crc16(uint16_t crc, const unsigned char *bytes, size_t length)
+{
+	for (size_t i = 0; i < length; i++) {
+		crc ^= bytes[i];
+
+		for (uint8_t j = 0; j < 8; j++)
+			crc = (crc >> 1) ^ (CRC16_MAGIC & (~(crc & 1) + 1));
+	}
+
+	return crc;
+}