/indra/llmessage/llxorcipher.cpp
https://bitbucket.org/lindenlab/viewer-beta/ · C++ · 128 lines · 82 code · 15 blank · 31 comment · 16 complexity · 06ba9f24dc31a42c1edcb2c4c1bd6c1e MD5 · raw file
- /**
- * @file llxorcipher.cpp
- * @brief Implementation of LLXORCipher
- *
- * $LicenseInfo:firstyear=2003&license=viewerlgpl$
- * Second Life Viewer Source Code
- * Copyright (C) 2010, Linden Research, Inc.
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation;
- * version 2.1 of the License only.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- *
- * Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA
- * $/LicenseInfo$
- */
- #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