library/std/src/os/fortanix_sgx/arch.rs

   1 //! SGX-specific access to architectural features.
   2 //!
   3 //! The functionality in this module is further documented in the Intel
   4 //! Software Developer's Manual, Volume 3, Chapter 40.
   5 #![unstable(feature = "sgx_platform", issue = "56975")]
   6
   7 use crate::mem::MaybeUninit;
   8
   9 /// Wrapper struct to force 16-byte alignment.
  10 #[repr(align(16))]
  11 #[unstable(feature = "sgx_platform", issue = "56975")]
  12 pub struct Align16<T>(pub T);
  13
  14 /// Wrapper struct to force 128-byte alignment.
  15 #[repr(align(128))]
  16 #[unstable(feature = "sgx_platform", issue = "56975")]
  17 pub struct Align128<T>(pub T);
  18
  19 /// Wrapper struct to force 512-byte alignment.
  20 #[repr(align(512))]
  21 #[unstable(feature = "sgx_platform", issue = "56975")]
  22 pub struct Align512<T>(pub T);
  23
  24 const ENCLU_EREPORT: u32 = 0;
  25 const ENCLU_EGETKEY: u32 = 1;
  26
  27 /// Call the `EGETKEY` instruction to obtain a 128-bit secret key.
  28 #[unstable(feature = "sgx_platform", issue = "56975")]
  29 pub fn egetkey(request: &Align512<[u8; 512]>) -> Result<Align16<[u8; 16]>, u32> {
  30     unsafe {
  31         let mut out = MaybeUninit::uninit();
  32         let error;
  33
  34         asm!(
  35             // rbx is reserved by LLVM
  36             "xchg %rbx, {0}",
  37             "enclu",
  38             "mov {0}, %rbx",
  39             inout(reg) request => _,
  40             inlateout("eax") ENCLU_EGETKEY => error,
  41             in("rcx") out.as_mut_ptr(),
  42             options(att_syntax, nostack),
  43         );
  44
  45         match error {
  46             0 => Ok(out.assume_init()),
  47             err => Err(err),
  48         }
  49     }
  50 }
  51
  52 /// Call the `EREPORT` instruction.
  53 ///
  54 /// This creates a cryptographic report describing the contents of the current
  55 /// enclave. The report may be verified by the enclave described in
  56 /// `targetinfo`.
  57 #[unstable(feature = "sgx_platform", issue = "56975")]
  58 pub fn ereport(
  59     targetinfo: &Align512<[u8; 512]>,
  60     reportdata: &Align128<[u8; 64]>,
  61 ) -> Align512<[u8; 432]> {
  62     unsafe {
  63         let mut report = MaybeUninit::uninit();
  64
  65         asm!(
  66             // rbx is reserved by LLVM
  67             "xchg %rbx, {0}",
  68             "enclu",
  69             "mov {0}, %rbx",
  70             inout(reg) targetinfo => _,
  71             in("eax") ENCLU_EREPORT,
  72             in("rcx") reportdata,
  73             in("rdx") report.as_mut_ptr(),
  74             options(att_syntax, preserves_flags, nostack),
  75         );
  76
  77         report.assume_init()
  78     }
  79 }