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Turning KeyPair into a struct (#119)

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This commit is contained in:
Kevin Lewi
2021-01-25 13:20:36 -08:00
committed by GitHub
parent e421aaad07
commit 6dc1c8b212
18 changed files with 420 additions and 1283 deletions
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src/oprf.rs
+12 -28
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@@ -28,16 +28,10 @@ static MODE_BASE: u8 = 0x00;
pub(crate) fn blind<R: RngCore + CryptoRng, G: GroupWithMapToCurve, H: Hash>(
input: &[u8],
blinding_factor_rng: &mut R,
#[cfg(test)] postprocess: fn(G::Scalar) -> G::Scalar,
) -> Result<(Token<G>, G), InternalPakeError> {
let blind = G::random_scalar(blinding_factor_rng);
let dst = [STR_VOPRF, &G::get_context_string(MODE_BASE)].concat();
let mapped_point = G::map_to_curve::<H>(input, &dst)?;
let blinding_factor = G::random_scalar(blinding_factor_rng);
#[cfg(test)]
let blind = postprocess(blinding_factor);
#[cfg(not(test))]
let blind = blinding_factor;
let blind_token = mapped_point * &blind;
Ok((
Token {
@@ -88,12 +82,7 @@ pub fn blind_shim<R: RngCore + CryptoRng, G: GroupWithMapToCurve, H: Hash>(
input: &[u8],
blinding_factor_rng: &mut R,
) -> Result<(Token<G>, G), InternalPakeError> {
blind::<R, G, H>(
input,
blinding_factor_rng,
#[cfg(test)]
std::convert::identity,
)
blind::<R, G, H>(input, blinding_factor_rng)
}
#[cfg(feature = "bench")]
@@ -129,27 +118,23 @@ mod tests {
use curve25519_dalek::ristretto::RistrettoPoint;
use generic_array::{arr, GenericArray};
use rand_core::OsRng;
use sha2::Sha256;
use sha2::Sha512;
fn prf(
input: &[u8],
oprf_key: &[u8; 32],
) -> GenericArray<u8, <RistrettoPoint as Group>::ElemLen> {
fn prf(input: &[u8], oprf_key: &[u8; 32]) -> GenericArray<u8, <Sha512 as Digest>::OutputSize> {
let dst = [STR_VOPRF, &RistrettoPoint::get_context_string(MODE_BASE)].concat();
let point = RistrettoPoint::map_to_curve::<Sha256>(input, &dst).unwrap();
let point = RistrettoPoint::map_to_curve::<Sha512>(input, &dst).unwrap();
let scalar =
RistrettoPoint::from_scalar_slice(GenericArray::from_slice(&oprf_key[..])).unwrap();
let res = point * scalar;
finalize::<RistrettoPoint, sha2::Sha256>(&input, &res.to_arr().to_vec(), b"")
finalize::<RistrettoPoint, sha2::Sha512>(&input, &res.to_arr().to_vec(), b"")
}
#[test]
fn oprf_retrieval() -> Result<(), InternalPakeError> {
let input = b"hunter2";
let mut rng = OsRng;
let (token, alpha) =
blind::<_, RistrettoPoint, Sha256>(&input[..], &mut rng, std::convert::identity)?;
let (token, alpha) = blind::<_, RistrettoPoint, Sha512>(&input[..], &mut rng)?;
let oprf_key_bytes = arr![
u8; 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23,
24, 25, 26, 27, 28, 29, 30, 31, 32,
@@ -157,7 +142,7 @@ mod tests {
let oprf_key = RistrettoPoint::from_scalar_slice(&oprf_key_bytes)?;
let beta = evaluate::<RistrettoPoint>(alpha, &oprf_key);
let res =
finalize::<RistrettoPoint, sha2::Sha256>(&token.data, &unblind(&token, beta), b"");
finalize::<RistrettoPoint, sha2::Sha512>(&token.data, &unblind(&token, beta), b"");
let res2 = prf(&input[..], &oprf_key.as_bytes());
assert_eq!(res, res2);
Ok(())
@@ -168,14 +153,13 @@ mod tests {
let mut rng = OsRng;
let mut input = vec![0u8; 64];
rng.fill_bytes(&mut input);
let (token, alpha) =
blind::<_, RistrettoPoint, Sha256>(&input, &mut rng, std::convert::identity).unwrap();
let (token, alpha) = blind::<_, RistrettoPoint, sha2::Sha512>(&input, &mut rng).unwrap();
let res =
finalize::<RistrettoPoint, sha2::Sha256>(&token.data, &unblind(&token, alpha), b"");
finalize::<RistrettoPoint, sha2::Sha512>(&token.data, &unblind(&token, alpha), b"");
let dst = [STR_VOPRF, &RistrettoPoint::get_context_string(MODE_BASE)].concat();
let point = RistrettoPoint::map_to_curve::<Sha256>(&input, &dst).unwrap();
let res2 = finalize::<RistrettoPoint, sha2::Sha256>(&input, &point.to_arr().to_vec(), b"");
let point = RistrettoPoint::map_to_curve::<Sha512>(&input, &dst).unwrap();
let res2 = finalize::<RistrettoPoint, sha2::Sha512>(&input, &point.to_arr().to_vec(), b"");
assert_eq!(res, res2);
}