Adam Wick
fa872c951a
Previously, we used a little bit of generation to drive a lot of Rust macros. This works, but it's a little confusing to read and write. In addition, we used a lot of implementations with variable timings based on their input, which isn't great for crypto. This is the start of an attempt to just generate all of the relevant Rust code directly, and to use timing-channel resistant implementations for most of the routines.
82 lines
2.3 KiB
Rust
82 lines
2.3 KiB
Rust
use std::cmp::*;
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pub fn compare(a: &[u64], b: &[u64]) -> Ordering {
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assert_eq!(a.len(), b.len(), "Incompatible numbers in comparison");
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let mut i = (a.len() - 1) as isize;
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while i >= 0 {
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let iu = i as usize;
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match a[iu].cmp(&b[iu]) {
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Ordering::Greater => return Ordering::Greater,
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Ordering::Less => return Ordering::Less,
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Ordering::Equal => i -= 1
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}
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}
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Ordering::Equal
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}
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macro_rules! cmp_impls {
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($name: ident) => {
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impl PartialEq for $name {
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fn eq(&self, rhs: &$name) -> bool {
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compare(&self.value, &rhs.value) == Ordering::Equal
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}
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}
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impl Eq for $name {}
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impl PartialOrd for $name {
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fn partial_cmp(&self, rhs: &$name) -> Option<Ordering> {
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Some(compare(&self.value, &rhs.value))
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}
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}
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impl Ord for $name {
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fn cmp(&self, rhs: &$name) -> Ordering {
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compare(&self.value, &rhs.value)
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}
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}
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}
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}
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#[cfg(test)]
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macro_rules! generate_cmp_tests {
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($name: ident, $lname: ident) => {
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#[test]
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fn $lname() {
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generate_cmp_tests!(body $name, $lname);
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}
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};
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(ignore $name: ident, $lname: ident) => {
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#[test]
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#[ignore]
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fn $lname() {
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generate_cmp_tests!(body $name, $lname);
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}
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};
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(body $name: ident, $lname: ident) => {
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let fname = build_test_path("cmp", stringify!($name));
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run_test(fname.to_string(), 5, |case| {
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let (neg0, abytes) = case.get("a").unwrap();
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let (neg1, bbytes) = case.get("b").unwrap();
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let (neg2, ebytes) = case.get("e").unwrap();
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let (neg3, gbytes) = case.get("g").unwrap();
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let (neg4, lbytes) = case.get("l").unwrap();
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assert!(!neg0 && !neg1 && !neg2 && !neg3 && !neg4);
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let a = $name::from_bytes(abytes);
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let b = $name::from_bytes(bbytes);
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let e = 1 == ebytes[0];
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let g = 1 == gbytes[0];
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let l = 1 == lbytes[0];
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assert_eq!(e, a == b);
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assert_eq!(g, a > b);
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assert_eq!(l, a < b);
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assert_eq!(e || g, a >= b);
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assert_eq!(e || l, a <= b);
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});
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};
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} |