vexahub/voprf-vx
4
0
Fork 0
Code Issues 1 Pull Requests Actions Releases 5 Activity

Improvements (#24)

Browse Source 
* Remove manual `Debug` impl for `InternalError`

* Remove unnecessary `#[macro_use]`

* Remove unnecessary  `tuple` handling in macro

* Improve serialization macro impl

* Improve `impl_traits_for` macro

* Re-direct `Drop` implementation

* Improve macro readability

* Fix rustdoc warnings

* Rust 1.51 has no support for `rustdoc` lints

* Change `i2osp` output to `GenericArray` from `Vec`

* Reduce calls to `to_vec()` and simplify conversion

* Adding zeroize tests

Co-authored-by: Kevin Lewi <[email protected]>
This commit is contained in:
daxpedda
2021-10-10 17:51:12 -07:00
committed by GitHub
co-authored by Kevin Lewi
parent c93600498e
commit fab7528a69
8 changed files with 442 additions and 352 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/group/expand.rs
+15 -11
View File
@@ -9,7 +9,7 @@ use crate::errors::InternalError;
use crate::serialization::i2osp;
use alloc::vec::Vec;
use digest::{BlockInput, Digest};
use generic_array::typenum::Unsigned;
use generic_array::typenum::{Unsigned, U1, U2};
// Computes ceil(x / y)
fn div_ceil(x: usize, y: usize) -> usize {
@@ -32,23 +32,27 @@ pub fn expand_message_xmd<H: BlockInput + Digest>(
dst: &[u8],
len_in_bytes: usize,
) -> Result<Vec<u8>, InternalError> {
let b_in_bytes = <H as Digest>::OutputSize::USIZE;
let r_in_bytes = <H as BlockInput>::BlockSize::USIZE;
let ell = div_ceil(len_in_bytes, b_in_bytes);
let ell = div_ceil(len_in_bytes, <H as Digest>::OutputSize::USIZE);
if ell > 255 {
return Err(InternalError::HashToCurveError);
}
let dst_prime = [dst, &i2osp(dst.len(), 1)?].concat();
let z_pad = i2osp(0, r_in_bytes)?;
let l_i_b_str = i2osp(len_in_bytes, 2)?;
let msg_prime = [&z_pad, msg, &l_i_b_str, &i2osp(0, 1)?, &dst_prime].concat();
let dst_prime = [dst, &i2osp::<U1>(dst.len())?].concat();
let z_pad = i2osp::<<H as BlockInput>::BlockSize>(0)?;
let l_i_b_str = i2osp::<U2>(len_in_bytes)?;
let msg_prime = [
&z_pad,
msg,
&l_i_b_str,
i2osp::<U1>(0)?.as_slice(),
&dst_prime,
]
.concat();
let mut b: Vec<Vec<u8>> = alloc::vec![H::digest(&msg_prime).to_vec()]; // b[0]
let mut h = H::new();
h.update(&b[0]);
h.update(&i2osp(1, 1)?);
h.update(&i2osp::<U1>(1)?);
h.update(&dst_prime);
b.push(h.finalize_reset().to_vec()); // b[1]
@@ -57,7 +61,7 @@ pub fn expand_message_xmd<H: BlockInput + Digest>(
for i in 2..(ell + 1) {
h.update(xor(&b[0], &b[i - 1])?);
h.update(&i2osp(i, 1)?);
h.update(&i2osp::<U1>(i)?);
h.update(&dst_prime);
b.push(h.finalize_reset().to_vec()); // b[i]
uniform_bytes.extend_from_slice(&b[i]);