This is not really functional yet, because the crypto is not yet
implemented. This, however follows the Auth pseudo function.
Backports commit a7bfa086c973a51fc18116c9d2e22a0e0069edba from qemu
Stripping out the authentication data does not require any crypto,
it merely requires the virtual address parameters.
Backports commit 04d13549fa10bb9775a90701e4e6fd0a2cbf83cb from qemu
The cryptographic internals are stubbed out for now,
but the enable and trap bits are checked.
Backports commit 0d43e1a2d29a05f7b0d5629caaff18733cbdf3bb from qemu
