Moved Stars45 to StarsEx

1 files changed, 168 insertions, 0 deletions

diff --git a/StarsEx/Encrypt.cpp b/StarsEx/Encrypt.cpp
new file mode 100644
index 0000000..44d07ca
--- /dev/null
+++ b/StarsEx/Encrypt.cpp
@@ -0,0 +1,168 @@
+/*  Starshatter: The Open Source Project
+    Copyright (c) 2021-2022, Starshatter: The Open Source Project Contributors
+    Copyright (c) 2011-2012, Starshatter OpenSource Distribution Contributors
+    Copyright (c) 1997-2006, Destroyer Studios LLC.
+
+    AUTHOR:       John DiCamillo
+
+
+    OVERVIEW
+    ========
+    Simple Encryption / Decryption class
+*/
+
+
+#include "Encrypt.h"
+#include "Utils.h"
+
+// +--------------------------------------------------------------------+
+
+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 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 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 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 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;
+}
+