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#![feature(asm)]
#![feature(llvm_asm)]

use std::mem::MaybeUninit;

/// Wrapper struct to force 16-byte alignment.
#[repr(align(16))]
pub struct Align16<T>(pub T);

/// Wrapper struct to force 128-byte alignment.
#[repr(align(128))]
pub struct Align128<T>(pub T);

/// Wrapper struct to force 512-byte alignment.
#[repr(align(512))]
pub struct Align512<T>(pub T);

const ENCLU_EREPORT: u32 = 0;
const ENCLU_EGETKEY: u32 = 1;

/// Call the `EGETKEY` instruction to obtain a 128-bit secret key.
pub fn egetkey(request: &Align512<[u8; 512]>) -> Result<Align16<[u8; 16]>, u32> {
    unsafe {
        let mut out = MaybeUninit::uninit();
        let mut error;

asm!(
            "enclu",
            inlateout("eax") ENCLU_EGETKEY => error,
            in("rbx") request,
            in("rcx") out.as_mut_ptr(),
            options(att_syntax, nostack),

);

match error {
            0 => Ok(out.assume_init()),
            err => Err(err),
        }
    }
}

/// Call the `EREPORT` instruction.
///
/// This creates a cryptographic report describing the contents of the current
/// enclave. The report may be verified by the enclave described in
/// `targetinfo`.
pub fn ereport(
    targetinfo: &Align512<[u8; 512]>,
    reportdata: &Align128<[u8; 64]>,
) -> Align512<[u8; 432]> {
    unsafe {
        let mut report = MaybeUninit::uninit();

// no output registers
        asm!(
            "enclu",
            in("eax") ENCLU_EREPORT,
            in("rbx") targetinfo,
            in("rcx") reportdata,
            in("rdx") report.as_mut_ptr(),
            options(att_syntax, preserves_flags, nostack),

);

report.assume_init()
    }
}