xboxkrnl: Add a bunch of crypto functions

third_party/crypto/des/des3.h

@@ -0,0 +1,40 @@
+#ifndef DES3_H
+#define DES3_H
+
+#include "des.h"
+
+class DES3
+{
+public:
+    DES3(ui64 k1, ui64 k2, ui64 k3) : des{ DES(k1), DES(k2), DES(k3) } {}
+    DES3(ui64* sk1, ui64* sk2, ui64* sk3) : des{ DES(sk1), DES(sk2), DES(sk3) } {}
+
+    inline ui64 encrypt(ui64 block)
+    {
+      return des[2].encrypt(des[1].decrypt(des[0].encrypt(block)));
+    }
+
+    inline ui64 decrypt(ui64 block)
+    {
+      return des[0].decrypt(des[1].encrypt(des[2].decrypt(block)));
+    }
+
+    inline ui64 crypt(ui64 block, bool bEncrypt)
+    {
+      if (bEncrypt)
+      {
+        return encrypt(block);
+      }
+      else
+      {
+        return decrypt(block);
+      }
+    }
+
+    inline DES* getDES() { return des; }
+
+private:
+    DES des[3];
+};
+
+#endif // DES3_H