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 use core::arch::asm;
   9
  10 /// Wrapper struct to force 16-byte alignment.
  11 #[repr(align(16))]
  12 #[unstable(feature = "sgx_platform", issue = "56975")]
  13 pub struct Align16<T>(pub T);
  14
  15 /// Wrapper struct to force 128-byte alignment.
  16 #[repr(align(128))]
  17 #[unstable(feature = "sgx_platform", issue = "56975")]
  18 pub struct Align128<T>(pub T);
  19
  20 /// Wrapper struct to force 512-byte alignment.
  21 #[repr(align(512))]
  22 #[unstable(feature = "sgx_platform", issue = "56975")]
  23 pub struct Align512<T>(pub T);
  24
  25 const ENCLU_EREPORT: u32 = 0;
  26 const ENCLU_EGETKEY: u32 = 1;
  27
  28 /// Call the `EGETKEY` instruction to obtain a 128-bit secret key.
  29 #[unstable(feature = "sgx_platform", issue = "56975")]
  30 pub fn egetkey(request: &Align512<[u8; 512]>) -> Result<Align16<[u8; 16]>, u32> {
  31     unsafe {
  32         let mut out = MaybeUninit::uninit();
  33         let error;
  34
  35         asm!(
  36             // rbx is reserved by LLVM
  37             "xchg %rbx, {0}",
  38             "enclu",
  39             "mov {0}, %rbx",
  40             inout(reg) request => _,
  41             inlateout("eax") ENCLU_EGETKEY => error,
  42             in("rcx") out.as_mut_ptr(),
  43             options(att_syntax, nostack),
  44         );
  45
  46         match error {
  47             0 => Ok(out.assume_init()),
  48             err => Err(err),
  49         }
  50     }
  51 }
  52
  53 /// Call the `EREPORT` instruction.
  54 ///
  55 /// This creates a cryptographic report describing the contents of the current
  56 /// enclave. The report may be verified by the enclave described in
  57 /// `targetinfo`.
  58 #[unstable(feature = "sgx_platform", issue = "56975")]
  59 pub fn ereport(
  60     targetinfo: &Align512<[u8; 512]>,
  61     reportdata: &Align128<[u8; 64]>,
  62 ) -> Align512<[u8; 432]> {
  63     unsafe {
  64         let mut report = MaybeUninit::uninit();
  65
  66         asm!(
  67             // rbx is reserved by LLVM
  68             "xchg %rbx, {0}",
  69             "enclu",
  70             "mov {0}, %rbx",
  71             inout(reg) targetinfo => _,
  72             in("eax") ENCLU_EREPORT,
  73             in("rcx") reportdata,
  74             in("rdx") report.as_mut_ptr(),
  75             options(att_syntax, preserves_flags, nostack),
  76         );
  77
  78         report.assume_init()
  79     }
  80 }