blob: 52acc6bf7a9ccc64f53cf657f97a9f95f5ea8ce1 [file] [log] [blame]
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use libc;
#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
extern {
pub fn rust_crypto_util_supports_aesni() -> u32;
}
#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
pub fn supports_aesni() -> bool {
unsafe {
rust_crypto_util_supports_aesni() != 0
}
}
extern {
pub fn rust_crypto_util_fixed_time_eq_asm(
lhsp: *const u8,
rhsp: *const u8,
count: libc::size_t) -> u32;
pub fn rust_crypto_util_secure_memset(
dst: *mut u8,
val: libc::uint8_t,
count: libc::size_t);
}
pub fn secure_memset(dst: &mut [u8], val: u8) {
unsafe {
rust_crypto_util_secure_memset(
dst.as_mut_ptr(),
val,
dst.len() as libc::size_t);
}
}
/// Compare two vectors using a fixed number of operations. If the two vectors are not of equal
/// length, the function returns false immediately.
pub fn fixed_time_eq(lhs: &[u8], rhs: &[u8]) -> bool {
if lhs.len() != rhs.len() {
false
} else {
let count = lhs.len() as libc::size_t;
unsafe {
let lhsp = lhs.get_unchecked(0);
let rhsp = rhs.get_unchecked(0);
rust_crypto_util_fixed_time_eq_asm(lhsp, rhsp, count) == 0
}
}
}
#[cfg(test)]
mod test {
use util::fixed_time_eq;
#[test]
pub fn test_fixed_time_eq() {
let a = [0, 1, 2];
let b = [0, 1, 2];
let c = [0, 1, 9];
let d = [9, 1, 2];
let e = [2, 1, 0];
let f = [2, 2, 2];
let g = [0, 0, 0];
assert!(fixed_time_eq(&a, &a));
assert!(fixed_time_eq(&a, &b));
assert!(!fixed_time_eq(&a, &c));
assert!(!fixed_time_eq(&a, &d));
assert!(!fixed_time_eq(&a, &e));
assert!(!fixed_time_eq(&a, &f));
assert!(!fixed_time_eq(&a, &g));
}
}