revm_precompile/bls12_381/
utils.rs

1use crate::bls12_381_const::{
2    FP_LENGTH, FP_PAD_BY, PADDED_FP_LENGTH, PADDED_G1_LENGTH, PADDED_G2_LENGTH,
3};
4use crate::PrecompileError;
5
6/// Removes zeros with which the precompile inputs are left padded to 64 bytes.
7pub(super) fn remove_fp_padding(input: &[u8]) -> Result<&[u8; FP_LENGTH], PrecompileError> {
8    if input.len() != PADDED_FP_LENGTH {
9        return Err(PrecompileError::Other(format!(
10            "Padded input should be {PADDED_FP_LENGTH} bytes, was {}",
11            input.len()
12        )));
13    }
14    let (padding, unpadded) = input.split_at(FP_PAD_BY);
15    if !padding.iter().all(|&x| x == 0) {
16        return Err(PrecompileError::Other(format!(
17            "{FP_PAD_BY} top bytes of input are not zero",
18        )));
19    }
20    Ok(unpadded.try_into().unwrap())
21}
22/// remove_g1_padding removes the padding applied to the Fp elements that constitute the
23/// encoded G1 element.
24pub(super) fn remove_g1_padding(input: &[u8]) -> Result<[&[u8; FP_LENGTH]; 2], PrecompileError> {
25    if input.len() != PADDED_G1_LENGTH {
26        return Err(PrecompileError::Other(format!(
27            "Input should be {PADDED_G1_LENGTH} bytes, was {}",
28            input.len()
29        )));
30    }
31
32    let x = remove_fp_padding(&input[..PADDED_FP_LENGTH])?;
33    let y = remove_fp_padding(&input[PADDED_FP_LENGTH..PADDED_G1_LENGTH])?;
34    Ok([x, y])
35}
36
37/// remove_g2_padding removes the padding applied to the Fp elements that constitute the
38/// encoded G2 element.
39pub(super) fn remove_g2_padding(input: &[u8]) -> Result<[&[u8; FP_LENGTH]; 4], PrecompileError> {
40    if input.len() != PADDED_G2_LENGTH {
41        return Err(PrecompileError::Other(format!(
42            "Input should be {PADDED_G2_LENGTH} bytes, was {}",
43            input.len()
44        )));
45    }
46
47    let mut input_fps = [&[0; FP_LENGTH]; 4];
48    for i in 0..4 {
49        input_fps[i] = remove_fp_padding(&input[i * PADDED_FP_LENGTH..(i + 1) * PADDED_FP_LENGTH])?;
50    }
51    Ok(input_fps)
52}
revm_precompile/bls12_381/utils.rs

revm_precompile/bls12_381/
utils.rs
