| 1 | // Copyright 2024 Brian Smith. |
|---|---|
| 2 | // |
| 3 | // Permission to use, copy, modify, and/or distribute this software for any |
| 4 | // purpose with or without fee is hereby granted, provided that the above |
| 5 | // copyright notice and this permission notice appear in all copies. |
| 6 | // |
| 7 | // THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES |
| 8 | // WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
| 9 | // MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY |
| 10 | // SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| 11 | // WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION |
| 12 | // OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN |
| 13 | // CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
| 14 | |
| 15 | use super::CHAINING_WORDS; |
| 16 | use crate::polyfill::slice::AsChunks; |
| 17 | use core::num::{NonZeroUsize, Wrapping}; |
| 18 | |
| 19 | /// `unsafe { T => f }` means it is safe to call `f` iff we can construct |
| 20 | /// a value of type `T`. |
| 21 | macro_rules! sha2_ffi { |
| 22 | ( $U:ty, $BLOCK_LEN:expr, unsafe { $Cpu:ty => $f:ident }, |
| 23 | $state:expr, $data:expr, $cpu:expr $(,)? ) => {{ |
| 24 | prefixed_extern! { |
| 25 | fn $f( |
| 26 | state: *mut [core::num::Wrapping<$U>; crate::digest::sha2::CHAINING_WORDS], |
| 27 | data: *const [u8; $BLOCK_LEN], |
| 28 | num: crate::c::NonZero_size_t); |
| 29 | } |
| 30 | // SAFETY: The user asserts that $f has the signature above and is safe |
| 31 | // to call if additionally we have a value of type `$Cpu`, which we do. |
| 32 | unsafe { |
| 33 | crate::digest::sha2::ffi::sha2_ffi::<$U, $Cpu, { $BLOCK_LEN }>($state, $data, $cpu, $f) |
| 34 | } |
| 35 | }}; |
| 36 | } |
| 37 | |
| 38 | macro_rules! sha2_32_ffi { |
| 39 | ( unsafe { $Cpu:ty => $f:ident }, $state:expr, $data:expr, $cpu:expr $(,)? ) => { |
| 40 | sha2_ffi!(u32, crate::digest::sha2::SHA256_BLOCK_LEN.into(), |
| 41 | unsafe { $Cpu => $f }, $state, $data, $cpu) |
| 42 | } |
| 43 | } |
| 44 | |
| 45 | macro_rules! sha2_64_ffi { |
| 46 | ( unsafe { $Cpu:ty => $f:ident }, $state:expr, $data:expr, $cpu:expr $(,)? ) => { |
| 47 | sha2_ffi!(u64, SHA512_BLOCK_LEN.into(), unsafe { $Cpu => $f }, $state, $data, $cpu) |
| 48 | } |
| 49 | } |
| 50 | |
| 51 | pub(super) unsafe fn sha2_ffi<U, Cpu, const BLOCK_LEN: usize>( |
| 52 | state: &mut [Wrapping<U>; CHAINING_WORDS], |
| 53 | data: AsChunks<u8, BLOCK_LEN>, |
| 54 | cpu: Cpu, |
| 55 | f: unsafe extern "C"fn( |
| 56 | *mut [Wrapping<U>; CHAINING_WORDS], |
| 57 | *const [u8; BLOCK_LEN], |
| 58 | crate::c::NonZero_size_t, |
| 59 | ), |
| 60 | ) { |
| 61 | if let Some(blocks: NonZero |
| 62 | let data: *const [u8; BLOCK_LEN] = data.as_ptr(); |
| 63 | let _: Cpu = cpu; |
| 64 | // SAFETY: |
| 65 | // * `blocks` is non-zero. |
| 66 | // * `data` is non-NULL and points to `blocks` blocks. |
| 67 | // * The caller asserted that `f` meets this contract if we have |
| 68 | // an instance of `Cpu`. |
| 69 | unsafe { f(state, data, blocks) } |
| 70 | } |
| 71 | } |
| 72 |