blob: 87e8bf0f307ceddceec7a1ebe6bee6ce35a911f9 [file] [log] [blame]
// Copyright 2018 Brian Smith.
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES
// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
// SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
// OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
// CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
use super::{Block, BLOCK_LEN};
use crate::c;
#[repr(transparent)]
pub struct Key(GCM128_KEY);
impl Key {
pub fn new(h_be: Block) -> Self {
extern "C" {
fn GFp_gcm128_init_htable(gcm_key: &mut GCM128_KEY, h_block: Block);
}
let mut r = Key(GCM128_KEY([Block::zero(); GCM128_HTABLE_LEN]));
unsafe {
GFp_gcm128_init_htable(&mut r.0, h_be);
}
r
}
}
#[repr(transparent)]
pub struct Context(GCM128_CONTEXT);
impl Context {
pub fn new(key: &Key, aad: &[u8]) -> Self {
let mut ctx = Context(GCM128_CONTEXT {
Xi: Block::zero(),
H_unused: Block::zero(),
key: key.0.clone(),
});
for ad in aad.chunks(BLOCK_LEN) {
let mut block = Block::zero();
block.partial_copy_from(ad);
ctx.update_block(block);
}
ctx
}
pub fn update_blocks(&mut self, input: &[u8]) {
debug_assert!(input.len() > 0);
debug_assert_eq!(input.len() % BLOCK_LEN, 0);
extern "C" {
fn GFp_gcm128_ghash(ctx: &mut Context, input: *const u8, input_len: c::size_t);
}
unsafe {
GFp_gcm128_ghash(self, input.as_ptr(), input.len());
}
}
pub fn update_block(&mut self, a: Block) {
extern "C" {
fn GFp_gcm128_gmult(ctx: &mut Context);
}
self.0.Xi.bitxor_assign(a);
unsafe {
GFp_gcm128_gmult(self);
}
}
pub(super) fn pre_finish<F>(self, f: F) -> super::Tag
where
F: FnOnce(Block) -> super::Tag,
{
f(self.0.Xi)
}
#[cfg(target_arch = "x86_64")]
pub(super) fn is_avx2(&self) -> bool {
extern "C" {
fn GFp_aesni_gcm_capable() -> c::int;
fn GFp_gcm_clmul_enabled() -> c::int;
}
1 == unsafe { GFp_gcm_clmul_enabled() } && 1 == unsafe { GFp_aesni_gcm_capable() }
}
}
// Keep in sync with `GCM128_KEY` in modes/internal.h.
#[derive(Clone)]
#[repr(C, align(16))]
struct GCM128_KEY([Block; GCM128_HTABLE_LEN]);
const GCM128_HTABLE_LEN: usize = 16;
// Keep in sync with `GCM128_CONTEXT` in modes/internal.h.
#[repr(C, align(16))]
struct GCM128_CONTEXT {
Xi: Block,
H_unused: Block,
key: GCM128_KEY,
}