From 966fe28c59f59fc8be795c8215b9352435982445 Mon Sep 17 00:00:00 2001 From: Aki Date: Thu, 30 Sep 2021 16:46:36 +0200 Subject: Merged nGenEx and Parser into Stars45 --- Stars45/Encrypt.cpp | 195 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 195 insertions(+) create mode 100644 Stars45/Encrypt.cpp (limited to 'Stars45/Encrypt.cpp') diff --git a/Stars45/Encrypt.cpp b/Stars45/Encrypt.cpp new file mode 100644 index 0000000..48ffcdf --- /dev/null +++ b/Stars45/Encrypt.cpp @@ -0,0 +1,195 @@ +/* Starshatter OpenSource Distribution + Copyright (c) 1997-2004, Destroyer Studios LLC. + All Rights Reserved. + + Redistribution and use in source and binary forms, with or without + modification, are permitted provided that the following conditions are met: + + * Redistributions of source code must retain the above copyright notice, + this list of conditions and the following disclaimer. + * Redistributions in binary form must reproduce the above copyright notice, + this list of conditions and the following disclaimer in the documentation + and/or other materials provided with the distribution. + * Neither the name "Destroyer Studios" nor the names of its contributors + may be used to endorse or promote products derived from this software + without specific prior written permission. + + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE + LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + POSSIBILITY OF SUCH DAMAGE. + + SUBSYSTEM: nGenEx.lib + FILE: Encrypt.cpp + AUTHOR: John DiCamillo + + + OVERVIEW + ======== + Simple Encryption / Decryption class +*/ + + +#include "MemDebug.h" +#include "Encrypt.h" + +// +--------------------------------------------------------------------+ + +void Print(const char* fmt, ...); + +static long k[4] = { + 0x3B398E26, + 0x40C29501, + 0x614D7630, + 0x7F59409A +}; + +static void encypher(long* v) +{ + DWORD y=v[0]; + DWORD z=v[1]; + DWORD sum=0; + DWORD delta=0x9e3779b9; // a key schedule constant + DWORD n=32; // num iterations + + while (n-->0) { // basic cycle start + sum += delta; + y += (z<<4)+k[0] ^ z+sum ^ (z>>5)+k[1]; + z += (y<<4)+k[2] ^ y+sum ^ (y>>5)+k[3]; + } + + v[0]=y; + v[1]=z; +} + +static void decypher(long* v) +{ + DWORD y=v[0]; + DWORD z=v[1]; + DWORD sum=0; + DWORD delta=0x9e3779b9; // a key schedule constant + DWORD n=32; // num iterations + + sum=delta<<5; + + while (n-->0) { + z-= (y<<4)+k[2] ^ y+sum ^ (y>>5)+k[3]; + y-= (z<<4)+k[0] ^ z+sum ^ (z>>5)+k[1]; + sum-=delta; + } + + v[0]=y; + v[1]=z; +} + +// +-------------------------------------------------------------------+ + +Text +Encryption::Encrypt(Text block) +{ + int len = block.length(); + + if (len < 1) + return Text(); + + // pad to eight byte chunks + if (len & 0x7) { + len /= 8; + len *= 8; + len += 8; + } + + BYTE* work = new(__FILE__,__LINE__) BYTE[len]; + ZeroMemory(work, len); + CopyMemory(work, block.data(), block.length()); + + long* v = (long*) work; + for (int i = 0; i < len/8; i++) { + encypher(v); + v += 2; + } + + Text cypher((const char*) work, len); + delete [] work; + return cypher; +} + +// +-------------------------------------------------------------------+ + +Text +Encryption::Decrypt(Text block) +{ + int len = block.length(); + + if (len & 0x7) { + Print("WARNING: attempt to decrypt odd length block (len=%d)\n", len); + return Text(); + } + + BYTE* work = new(__FILE__,__LINE__) BYTE[len]; + CopyMemory(work, block.data(), len); + + long* v = (long*) work; + for (int i = 0; i < len/8; i++) { + decypher(v); + v += 2; + } + + Text clear((const char*) work, len); + delete [] work; + return clear; +} + +// +-------------------------------------------------------------------+ + +static const char* codes = "abcdefghijklmnop"; + +Text +Encryption::Encode(Text block) +{ + int len = block.length() * 2; + char* work = new(__FILE__,__LINE__) char[len + 1]; + + for (int i = 0; i < block.length(); i++) { + BYTE b = (BYTE) (block.data()[i]); + work[2*i] = codes[b>>4 & 0xf]; + work[2*i+1] = codes[b & 0xf]; + } + + work[len] = 0; + + Text code(work, len); + delete [] work; + return code; +} + +// +-------------------------------------------------------------------+ + +Text +Encryption::Decode(Text block) +{ + int len = block.length() / 2; + char* work = new(__FILE__,__LINE__) char[len + 1]; + + for (int i = 0; i < len; i++) { + char u = block[2*i]; + char l = block[2*i + 1]; + + work[i] = (u - codes[0]) << 4 | + (l - codes[0]); + } + + work[len] = 0; + + Text clear(work, len); + delete [] work; + return clear; +} + -- cgit v1.1