Reconstruction of des.exe/undes.exe

2026-09-09 23:28:46 +02:00
parent b90136f137
commit 5aa37bf374
64 changed files with 13344 additions and 2 deletions
@@ -0,0 +1,65 @@
+/* Optimized RC4 code, from an unknown source ("and they knew not from whence
+   it had come...") */
+
+#ifdef _MSC_VER
+  #include "rc4.h"
+#else
+  #include "rc4/rc4.h"
+#endif /* _MSC_VER */
+
+void rc4ExpandKey( RC4KEY *rc4, unsigned char const *key, int keylen )
+	{
+	int x, keypos = 0;
+	rc4word sx, y = 0;
+	rc4word *state = &rc4->state[ 0 ];
+
+	rc4->x = rc4->y = 0;
+
+	for( x = 0; x < 256; x++ )
+		state[ x ] = x;
+
+	for( x = 0; x < 256; x++ )
+		{
+		sx = state[ x ];
+		y += sx + key[ keypos ];
+#ifdef USE_LONG_RC4
+		y &= 0xFF;
+#endif /* USE_LONG_RC4 */
+		state[ x ] = state[ y ];
+		state[ y ] = sx;
+
+		if( ++keypos == keylen )
+			keypos = 0;
+		}
+	}
+
+void rc4Crypt( RC4KEY *rc4, unsigned char *data, int len )
+{
+	rc4word x = rc4->x, y = rc4->y;
+	rc4word sx, sy;
+	rc4word *state = &rc4->state[ 0 ];
+
+	while (len--) {
+		x++;
+#ifdef USE_LONG_RC4
+		x &= 0xFF;
+#endif /* USE_LONG_RC4 */
+		sx = state[ x ];
+		y += sx;
+#ifdef USE_LONG_RC4
+		y &= 0xFF;
+#endif /* USE_LONG_RC4 */
+		sy = state[ y ];
+		state[ y ] = sx;
+		state[ x ] = sy;
+
+#ifdef USE_LONG_RC4
+		*data++ ^= state[ ( unsigned char ) ( sx+sy ) ];
+#else
+		*data++ ^= state[ ( sx+sy ) & 0xFF ];
+#endif /* USE_LONG_RC4 */
+	}
+
+	rc4->x = x;
+	rc4->y = y;
+}