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| author | FWoltermann@gmail.com <FWoltermann@gmail.com@076cb2c4-205e-83fd-5cf3-1be9aa105544> | 2011-12-08 14:53:40 +0000 |
|---|---|---|
| committer | FWoltermann@gmail.com <FWoltermann@gmail.com@076cb2c4-205e-83fd-5cf3-1be9aa105544> | 2011-12-08 14:53:40 +0000 |
| commit | e33e19d0587146859d48a134ec9fd94e7b7ba5cd (patch) | |
| tree | 69d048c8801858d2756ab3a487090a7a1b74bf14 /nGenEx/Encrypt.cpp | |
| download | starshatter-e33e19d0587146859d48a134ec9fd94e7b7ba5cd.zip starshatter-e33e19d0587146859d48a134ec9fd94e7b7ba5cd.tar.gz starshatter-e33e19d0587146859d48a134ec9fd94e7b7ba5cd.tar.bz2 | |
Initial upload
Diffstat (limited to 'nGenEx/Encrypt.cpp')
| -rw-r--r-- | nGenEx/Encrypt.cpp | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/nGenEx/Encrypt.cpp b/nGenEx/Encrypt.cpp new file mode 100644 index 0000000..6fa79d2 --- /dev/null +++ b/nGenEx/Encrypt.cpp @@ -0,0 +1,171 @@ +/* Project nGenEx
+ Destroyer Studios LLC
+ Copyright © 1997-2004. All Rights Reserved.
+
+ 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;
+}
+
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