129 lines
3.1 KiB
C++
129 lines
3.1 KiB
C++
/**
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* @file llxorcipher.cpp
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* @brief Implementation of LLXORCipher
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*
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* $LicenseInfo:firstyear=2003&license=viewerlgpl$
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* Second Life Viewer Source Code
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* Copyright (C) 2010, Linden Research, Inc.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation;
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* version 2.1 of the License only.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*
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* Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA
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* $/LicenseInfo$
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*/
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#include "linden_common.h"
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#include "llxorcipher.h"
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#include "llerror.h"
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///----------------------------------------------------------------------------
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/// Class LLXORCipher
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///----------------------------------------------------------------------------
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LLXORCipher::LLXORCipher(const U8* pad, U32 pad_len) :
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mPad(NULL),
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mHead(NULL),
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mPadLen(0)
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{
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init(pad, pad_len);
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}
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// Destroys the object
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LLXORCipher::~LLXORCipher()
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{
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init(NULL, 0);
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}
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LLXORCipher::LLXORCipher(const LLXORCipher& cipher) :
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mPad(NULL),
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mHead(NULL),
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mPadLen(0)
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{
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init(cipher.mPad, cipher.mPadLen);
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}
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LLXORCipher& LLXORCipher::operator=(const LLXORCipher& cipher)
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{
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if(this == &cipher) return *this;
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init(cipher.mPad, cipher.mPadLen);
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return *this;
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}
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U32 LLXORCipher::encrypt(const U8* src, U32 src_len, U8* dst, U32 dst_len)
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{
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if(!src || !src_len || !dst || !dst_len || !mPad) return 0;
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U8* pad_end = mPad + mPadLen;
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U32 count = src_len;
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while(count--)
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{
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*dst++ = *src++ ^ *mHead++;
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if(mHead >= pad_end) mHead = mPad;
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}
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return src_len;
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}
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U32 LLXORCipher::decrypt(const U8* src, U32 src_len, U8* dst, U32 dst_len)
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{
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// xor is a symetric cipher, thus, just call the other function.
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return encrypt(src, src_len, dst, dst_len);
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}
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U32 LLXORCipher::requiredEncryptionSpace(U32 len) const
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{
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return len;
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}
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void LLXORCipher::init(const U8* pad, U32 pad_len)
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{
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if(mPad)
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{
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delete [] mPad;
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mPad = NULL;
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mPadLen = 0;
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}
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if(pad && pad_len)
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{
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mPadLen = pad_len;
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mPad = new U8[mPadLen];
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if (mPad != NULL)
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{
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memcpy(mPad, pad, mPadLen); /* Flawfinder : ignore */
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}
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}
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mHead = mPad;
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}
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#ifdef _DEBUG
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// static
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BOOL LLXORCipher::testHarness()
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{
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const U32 PAD_LEN = 3;
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const U8 PAD[] = "abc";
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const S32 MSG_LENGTH = 12;
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const char MESSAGE[MSG_LENGTH+1] = "gesundheight"; /* Flawfinder : ignore */
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U8 encrypted[MSG_LENGTH];
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U8 decrypted[MSG_LENGTH];
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LLXORCipher cipher(PAD, PAD_LEN);
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cipher.encrypt((U8*)MESSAGE, MSG_LENGTH, encrypted, MSG_LENGTH);
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cipher.decrypt(encrypted, MSG_LENGTH, decrypted, MSG_LENGTH);
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if(0 != memcmp((void*)MESSAGE, decrypted, MSG_LENGTH)) return FALSE;
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return TRUE;
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}
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#endif
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