90 lines
2.5 KiB
C++
90 lines
2.5 KiB
C++
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//#pragma title( "Cipher.cpp - Very simple cipher for encryption" )
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/*
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Copyright (c) 1995-1998, Mission Critical Software, Inc. All rights reserved.
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===============================================================================
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Module - Cipher.cpp
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System - Common
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Author - Tom Bernhardt
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Created - 1996-01-21
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Description - Very simple Cipher routine for network packet password
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encryption. This is a symmetrical cipher where applying
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it twice will revert it to its orignial form. One of its
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functions is a one's complement so it assumes that no char
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will have the value of '\xff' to erroneously pre-terminate
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the resultant string.
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NOTE: This is obviously so simple that it can be easily
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cracked by either single stepping the code or comparing sequences
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of known values and their encrypted result. Its only use
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is to keep out the casual observer/hacker. It should be replaced
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by heavy public key encryption when possible.
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Updates -
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===============================================================================
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*/
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#include <windows.h>
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#include "Cipher.hpp"
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void
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SimpleCipher(
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WCHAR * str // i/o-string to encrypt
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)
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{
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WCHAR * c;
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// exchange nibbles and NOT result or each char
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for ( c = str; *c; c++ )
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*c = ~( *c >> 4 | *c << 4 );
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// exchange chars around middle
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for ( --c; c > str; c--, str++ )
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{
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*c ^= *str;
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*str ^= *c;
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*c ^= *str;
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}
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}
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void
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SimpleCipher(
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char unsigned * str // i/o-string to encrypt
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)
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{
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char unsigned * c;
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// exchange nibbles and NOT result or each char
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for ( c = str; *c; c++ )
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*c = ~( *c >> 4 | *c << 4 );
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// exchange chars around middle
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for ( --c; c > str; c--, str++ )
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{
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*c ^= *str;
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*str ^= *c;
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*c ^= *str;
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}
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}
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void
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SimpleCipher(
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char unsigned * str ,// i/o-string to encrypt
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int len // in -length of string
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)
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{
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char unsigned * c;
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// exchange nibbles and NOT result or each char
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for ( c = str; len--; c++ )
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*c = ~( *c >> 4 | *c << 4 );
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// exchange chars around middle
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for ( --c; c > str; c--, str++ )
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{
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*c ^= *str;
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*str ^= *c;
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*c ^= *str;
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}
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}
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// Cipher.cpp - end of file
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