xboxkrnl: Add a bunch of crypto functions

third_party/crypto/des/des.h

@@ -0,0 +1,51 @@
+#ifndef DES_H
+#define DES_H
+
+#include <cstdint>
+
+typedef uint64_t ui64;
+typedef uint32_t ui32;
+typedef uint8_t ui8;
+
+class DES
+{
+public:
+    DES(ui64 key);
+    DES(ui64 *sub_key);
+    ui64 des(ui64 block, bool mode);
+
+    ui64 encrypt(ui64 block);
+    ui64 decrypt(ui64 block);
+
+    static ui64 encrypt(ui64 block, ui64 key);
+    static ui64 decrypt(ui64 block, ui64 key);
+
+    static void set_parity(ui8 *key, int length, ui8 *out) {
+      for (int i = 0; i < length; i++) {
+        ui8 parity = key[i];
+
+        parity ^= parity >> 4;
+        parity ^= parity >> 2;
+        parity ^= parity >> 1;
+
+        out[i] = (key[i] & 0xFE) | (~parity & 1);
+      }
+    }
+
+    const ui64 *get_sub_key() const { return sub_key; }
+    void set_sub_key(ui64 *key);
+
+protected:
+    void keygen(ui64 key);
+
+    ui64 ip(ui64 block);
+    ui64 fp(ui64 block);
+
+    void feistel(ui32 &L, ui32 &R, ui32 F);
+    ui32 f(ui32 R, ui64 k);
+
+private:
+    ui64 sub_key[16]; // 48 bits each
+};
+
+#endif // DES_H