lighthouse/tests/ef_tests/src/cases/bls_g2_uncompressed.rs

use super::*;
use crate::case_result::compare_result;
use bls::hash_on_g2;
use serde_derive::Deserialize;

#[derive(Debug, Clone, Deserialize)]
pub struct BlsG2UncompressedInput {
    pub message: String,
    pub domain: String,
}

#[derive(Debug, Clone, Deserialize)]
pub struct BlsG2Uncompressed {
    pub input: BlsG2UncompressedInput,
    pub output: Vec<Vec<String>>,
}

impl YamlDecode for BlsG2Uncompressed {
    fn yaml_decode(yaml: &str) -> Result<Self, Error> {
        Ok(serde_yaml::from_str(yaml).unwrap())
    }
}

impl Case for BlsG2Uncompressed {
    fn result(&self, _case_index: usize) -> Result<(), Error> {
        // Convert message and domain to required types
        let msg = hex::decode(&self.input.message[2..])
            .map_err(|e| Error::FailedToParseTest(format!("{:?}", e)))?;
        let d = hex::decode(&self.input.domain[2..])
            .map_err(|e| Error::FailedToParseTest(format!("{:?}", e)))?;
        let d = bytes_to_u64(&d);

        // Calculate the point and convert it to compressed bytes
        let point = hash_on_g2(&msg, d);
        let mut point_bytes = [0 as u8; 288];
        point.getpx().geta().tobytearray(&mut point_bytes, 0);
        point.getpx().getb().tobytearray(&mut point_bytes, 48);
        point.getpy().geta().tobytearray(&mut point_bytes, 96);
        point.getpy().getb().tobytearray(&mut point_bytes, 144);
        point.getpz().geta().tobytearray(&mut point_bytes, 192);
        point.getpz().getb().tobytearray(&mut point_bytes, 240);

        // Convert the output to one set of bytes (x.a, x.b, y.a, y.b, z.a, z.b)
        let mut decoded: Vec<u8> = vec![];
        for coordinate in &self.output {
            let mut decoded_part = hex::decode(&coordinate[0][2..])
                .map_err(|e| Error::FailedToParseTest(format!("{:?}", e)))?;
            decoded.append(&mut decoded_part);
            decoded_part = hex::decode(&coordinate[1][2..])
                .map_err(|e| Error::FailedToParseTest(format!("{:?}", e)))?;
            decoded.append(&mut decoded_part);
        }

        compare_result::<Vec<u8>, Vec<u8>>(&Ok(point_bytes.to_vec()), &Some(decoded))
    }
}

// Converts a vector to u64 (from big endian)
fn bytes_to_u64(array: &[u8]) -> u64 {
    let mut result: u64 = 0;
    for (i, value) in array.iter().rev().enumerate() {
        if i == 8 {
            break;
        }
        result += u64::pow(2, i as u32 * 8) * u64::from(*value);
    }
    result
}