Imported existing code

indra/llmessage/llxorcipher.cpp

@@ -0,0 +1,134 @@
+/** 
+ * @file llxorcipher.cpp
+ * @brief Implementation of LLXORCipher
+ *
+ * $LicenseInfo:firstyear=2003&license=viewergpl$
+ * 
+ * Copyright (c) 2003-2009, Linden Research, Inc.
+ * 
+ * Second Life Viewer Source Code
+ * The source code in this file ("Source Code") is provided by Linden Lab
+ * to you under the terms of the GNU General Public License, version 2.0
+ * ("GPL"), unless you have obtained a separate licensing agreement
+ * ("Other License"), formally executed by you and Linden Lab.  Terms of
+ * the GPL can be found in doc/GPL-license.txt in this distribution, or
+ * online at http://secondlifegrid.net/programs/open_source/licensing/gplv2
+ * 
+ * There are special exceptions to the terms and conditions of the GPL as
+ * it is applied to this Source Code. View the full text of the exception
+ * in the file doc/FLOSS-exception.txt in this software distribution, or
+ * online at
+ * http://secondlifegrid.net/programs/open_source/licensing/flossexception
+ * 
+ * By copying, modifying or distributing this software, you acknowledge
+ * that you have read and understood your obligations described above,
+ * and agree to abide by those obligations.
+ * 
+ * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
+ * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
+ * COMPLETENESS OR PERFORMANCE.
+ * $/LicenseInfo$
+ */
+
+#include "linden_common.h"
+
+#include "llxorcipher.h"
+
+#include "llerror.h"
+
+///----------------------------------------------------------------------------
+/// Class LLXORCipher
+///----------------------------------------------------------------------------
+
+LLXORCipher::LLXORCipher(const U8* pad, U32 pad_len) :
+	mPad(NULL),
+	mHead(NULL),
+	mPadLen(0)
+{
+	init(pad, pad_len);
+}
+
+// Destroys the object
+LLXORCipher::~LLXORCipher()
+{
+	init(NULL, 0);
+}
+
+LLXORCipher::LLXORCipher(const LLXORCipher& cipher) :
+	mPad(NULL),
+	mHead(NULL),
+	mPadLen(0)
+{
+	init(cipher.mPad, cipher.mPadLen);
+}
+
+LLXORCipher& LLXORCipher::operator=(const LLXORCipher& cipher)
+{
+	if(this == &cipher) return *this;
+	init(cipher.mPad, cipher.mPadLen);
+	return *this;
+}
+
+U32 LLXORCipher::encrypt(const U8* src, U32 src_len, U8* dst, U32 dst_len)
+{
+	if(!src || !src_len || !dst || !dst_len || !mPad) return 0;
+	U8* pad_end = mPad + mPadLen;
+	U32 count = src_len;
+	while(count--)
+	{
+		*dst++ = *src++ ^ *mHead++;
+		if(mHead >= pad_end) mHead = mPad;
+	}
+	return src_len;
+}
+
+U32 LLXORCipher::decrypt(const U8* src, U32 src_len, U8* dst, U32 dst_len)
+{
+	// xor is a symetric cipher, thus, just call the other function.
+	return encrypt(src, src_len, dst, dst_len);
+}
+
+U32 LLXORCipher::requiredEncryptionSpace(U32 len) const
+{
+	return len;
+}
+
+void LLXORCipher::init(const U8* pad, U32 pad_len)
+{
+	if(mPad)
+	{
+		delete [] mPad;
+		mPad = NULL;
+		mPadLen = 0;
+	}
+	if(pad && pad_len)
+	{
+		mPadLen = pad_len;
+		mPad = new U8[mPadLen];
+		if (mPad != NULL)
+		{
+			memcpy(mPad, pad, mPadLen); /* Flawfinder : ignore */
+		}
+	}
+	mHead = mPad;
+}
+
+#ifdef _DEBUG
+// static
+BOOL LLXORCipher::testHarness()
+{
+	const U32 PAD_LEN = 3;
+	const U8 PAD[] = "abc";
+	const S32 MSG_LENGTH = 12;
+	const char MESSAGE[MSG_LENGTH+1] = "gesundheight";		/* Flawfinder : ignore */
+	U8 encrypted[MSG_LENGTH];
+	U8 decrypted[MSG_LENGTH];
+
+	LLXORCipher cipher(PAD, PAD_LEN);
+	cipher.encrypt((U8*)MESSAGE, MSG_LENGTH, encrypted, MSG_LENGTH);
+	cipher.decrypt(encrypted, MSG_LENGTH, decrypted, MSG_LENGTH);
+
+	if(0 != memcmp((void*)MESSAGE, decrypted, MSG_LENGTH)) return FALSE;
+	return TRUE;
+}
+#endif