diff options
Diffstat (limited to 'vendor/elliptic-curve/src/hash2curve')
8 files changed, 1321 insertions, 0 deletions
diff --git a/vendor/elliptic-curve/src/hash2curve/group_digest.rs b/vendor/elliptic-curve/src/hash2curve/group_digest.rs new file mode 100644 index 0000000..ea7f047 --- /dev/null +++ b/vendor/elliptic-curve/src/hash2curve/group_digest.rs @@ -0,0 +1,123 @@ +//! Traits for handling hash to curve. + +use super::{hash_to_field, ExpandMsg, FromOkm, MapToCurve}; +use crate::{CurveArithmetic, ProjectivePoint, Result}; +use group::cofactor::CofactorGroup; + +/// Adds hashing arbitrary byte sequences to a valid group element +pub trait GroupDigest: CurveArithmetic +where + ProjectivePoint<Self>: CofactorGroup, +{ + /// The field element representation for a group value with multiple elements + type FieldElement: FromOkm + MapToCurve<Output = ProjectivePoint<Self>> + Default + Copy; + + /// Computes the hash to curve routine. + /// + /// From <https://www.ietf.org/archive/id/draft-irtf-cfrg-hash-to-curve-13.html>: + /// + /// > Uniform encoding from byte strings to points in G. + /// > That is, the distribution of its output is statistically close + /// > to uniform in G. + /// > This function is suitable for most applications requiring a random + /// > oracle returning points in G assuming a cryptographically secure + /// > hash function is used. + /// + /// # Examples + /// + /// ## Using a fixed size hash function + /// + /// ```ignore + /// let pt = ProjectivePoint::hash_from_bytes::<ExpandMsgXmd<sha2::Sha256>>(b"test data", b"CURVE_XMD:SHA-256_SSWU_RO_"); + /// ``` + /// + /// ## Using an extendable output function + /// + /// ```ignore + /// let pt = ProjectivePoint::hash_from_bytes::<ExpandMsgXof<sha3::Shake256>>(b"test data", b"CURVE_XOF:SHAKE-256_SSWU_RO_"); + /// ``` + /// + /// # Errors + /// See implementors of [`ExpandMsg`] for errors: + /// - [`ExpandMsgXmd`] + /// - [`ExpandMsgXof`] + /// + /// `len_in_bytes = <Self::FieldElement as FromOkm>::Length * 2` + /// + /// [`ExpandMsgXmd`]: crate::hash2curve::ExpandMsgXmd + /// [`ExpandMsgXof`]: crate::hash2curve::ExpandMsgXof + fn hash_from_bytes<'a, X: ExpandMsg<'a>>( + msgs: &[&[u8]], + dsts: &'a [&'a [u8]], + ) -> Result<ProjectivePoint<Self>> { + let mut u = [Self::FieldElement::default(), Self::FieldElement::default()]; + hash_to_field::<X, _>(msgs, dsts, &mut u)?; + let q0 = u[0].map_to_curve(); + let q1 = u[1].map_to_curve(); + // Ideally we could add and then clear cofactor once + // thus saving a call but the field elements may not + // add properly due to the underlying implementation + // which could result in an incorrect subgroup. + // This is caused curve coefficients being different than + // what is usually implemented. + // FieldElement expects the `a` and `b` to be the original values + // isogenies are different with curves like k256 and bls12-381. + // This problem doesn't manifest for curves with no isogeny like p256. + // For k256 and p256 clear_cofactor doesn't do anything anyway so it will be a no-op. + Ok(q0.clear_cofactor().into() + q1.clear_cofactor()) + } + + /// Computes the encode to curve routine. + /// + /// From <https://www.ietf.org/archive/id/draft-irtf-cfrg-hash-to-curve-13.html>: + /// + /// > Nonuniform encoding from byte strings to + /// > points in G. That is, the distribution of its output is not + /// > uniformly random in G: the set of possible outputs of + /// > encode_to_curve is only a fraction of the points in G, and some + /// > points in this set are more likely to be output than others. + /// + /// # Errors + /// See implementors of [`ExpandMsg`] for errors: + /// - [`ExpandMsgXmd`] + /// - [`ExpandMsgXof`] + /// + /// `len_in_bytes = <Self::FieldElement as FromOkm>::Length` + /// + /// [`ExpandMsgXmd`]: crate::hash2curve::ExpandMsgXmd + /// [`ExpandMsgXof`]: crate::hash2curve::ExpandMsgXof + fn encode_from_bytes<'a, X: ExpandMsg<'a>>( + msgs: &[&[u8]], + dsts: &'a [&'a [u8]], + ) -> Result<ProjectivePoint<Self>> { + let mut u = [Self::FieldElement::default()]; + hash_to_field::<X, _>(msgs, dsts, &mut u)?; + let q0 = u[0].map_to_curve(); + Ok(q0.clear_cofactor().into()) + } + + /// Computes the hash to field routine according to + /// <https://www.ietf.org/archive/id/draft-irtf-cfrg-hash-to-curve-13.html#section-5> + /// and returns a scalar. + /// + /// # Errors + /// See implementors of [`ExpandMsg`] for errors: + /// - [`ExpandMsgXmd`] + /// - [`ExpandMsgXof`] + /// + /// `len_in_bytes = <Self::Scalar as FromOkm>::Length` + /// + /// [`ExpandMsgXmd`]: crate::hash2curve::ExpandMsgXmd + /// [`ExpandMsgXof`]: crate::hash2curve::ExpandMsgXof + fn hash_to_scalar<'a, X: ExpandMsg<'a>>( + msgs: &[&[u8]], + dsts: &'a [&'a [u8]], + ) -> Result<Self::Scalar> + where + Self::Scalar: FromOkm, + { + let mut u = [Self::Scalar::default()]; + hash_to_field::<X, _>(msgs, dsts, &mut u)?; + Ok(u[0]) + } +} diff --git a/vendor/elliptic-curve/src/hash2curve/hash2field.rs b/vendor/elliptic-curve/src/hash2curve/hash2field.rs new file mode 100644 index 0000000..67ede11 --- /dev/null +++ b/vendor/elliptic-curve/src/hash2curve/hash2field.rs @@ -0,0 +1,48 @@ +//! Traits for hashing to field elements. +//! +//! <https://datatracker.ietf.org/doc/draft-irtf-cfrg-hash-to-curve> + +mod expand_msg; + +pub use expand_msg::{xmd::*, xof::*, *}; + +use crate::{Error, Result}; +use generic_array::{typenum::Unsigned, ArrayLength, GenericArray}; + +/// The trait for helping to convert to a field element. +pub trait FromOkm { + /// The number of bytes needed to convert to a field element. + type Length: ArrayLength<u8>; + + /// Convert a byte sequence into a field element. + fn from_okm(data: &GenericArray<u8, Self::Length>) -> Self; +} + +/// Convert an arbitrary byte sequence into a field element. +/// +/// <https://tools.ietf.org/html/draft-irtf-cfrg-hash-to-curve-11#section-5.3> +/// +/// # Errors +/// See implementors of [`ExpandMsg`] for errors: +/// - [`ExpandMsgXmd`] +/// - [`ExpandMsgXof`] +/// +/// `len_in_bytes = T::Length * out.len()` +/// +/// [`ExpandMsgXmd`]: crate::hash2field::ExpandMsgXmd +/// [`ExpandMsgXof`]: crate::hash2field::ExpandMsgXof +#[doc(hidden)] +pub fn hash_to_field<'a, E, T>(data: &[&[u8]], domain: &'a [&'a [u8]], out: &mut [T]) -> Result<()> +where + E: ExpandMsg<'a>, + T: FromOkm + Default, +{ + let len_in_bytes = T::Length::to_usize().checked_mul(out.len()).ok_or(Error)?; + let mut tmp = GenericArray::<u8, <T as FromOkm>::Length>::default(); + let mut expander = E::expand_message(data, domain, len_in_bytes)?; + for o in out.iter_mut() { + expander.fill_bytes(&mut tmp); + *o = T::from_okm(&tmp); + } + Ok(()) +} diff --git a/vendor/elliptic-curve/src/hash2curve/hash2field/expand_msg.rs b/vendor/elliptic-curve/src/hash2curve/hash2field/expand_msg.rs new file mode 100644 index 0000000..96a659b --- /dev/null +++ b/vendor/elliptic-curve/src/hash2curve/hash2field/expand_msg.rs @@ -0,0 +1,145 @@ +//! `expand_message` interface `for hash_to_field`. + +pub(super) mod xmd; +pub(super) mod xof; + +use crate::{Error, Result}; +use digest::{Digest, ExtendableOutput, Update, XofReader}; +use generic_array::typenum::{IsLess, U256}; +use generic_array::{ArrayLength, GenericArray}; + +/// Salt when the DST is too long +const OVERSIZE_DST_SALT: &[u8] = b"H2C-OVERSIZE-DST-"; +/// Maximum domain separation tag length +const MAX_DST_LEN: usize = 255; + +/// Trait for types implementing expand_message interface for `hash_to_field`. +/// +/// # Errors +/// See implementors of [`ExpandMsg`] for errors. +pub trait ExpandMsg<'a> { + /// Type holding data for the [`Expander`]. + type Expander: Expander + Sized; + + /// Expands `msg` to the required number of bytes. + /// + /// Returns an expander that can be used to call `read` until enough + /// bytes have been consumed + fn expand_message( + msgs: &[&[u8]], + dsts: &'a [&'a [u8]], + len_in_bytes: usize, + ) -> Result<Self::Expander>; +} + +/// Expander that, call `read` until enough bytes have been consumed. +pub trait Expander { + /// Fill the array with the expanded bytes + fn fill_bytes(&mut self, okm: &mut [u8]); +} + +/// The domain separation tag +/// +/// Implements [section 5.4.3 of `draft-irtf-cfrg-hash-to-curve-13`][dst]. +/// +/// [dst]: https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-hash-to-curve-13#section-5.4.3 +pub(crate) enum Domain<'a, L> +where + L: ArrayLength<u8> + IsLess<U256>, +{ + /// > 255 + Hashed(GenericArray<u8, L>), + /// <= 255 + Array(&'a [&'a [u8]]), +} + +impl<'a, L> Domain<'a, L> +where + L: ArrayLength<u8> + IsLess<U256>, +{ + pub fn xof<X>(dsts: &'a [&'a [u8]]) -> Result<Self> + where + X: Default + ExtendableOutput + Update, + { + if dsts.is_empty() { + Err(Error) + } else if dsts.iter().map(|dst| dst.len()).sum::<usize>() > MAX_DST_LEN { + let mut data = GenericArray::<u8, L>::default(); + let mut hash = X::default(); + hash.update(OVERSIZE_DST_SALT); + + for dst in dsts { + hash.update(dst); + } + + hash.finalize_xof().read(&mut data); + + Ok(Self::Hashed(data)) + } else { + Ok(Self::Array(dsts)) + } + } + + pub fn xmd<X>(dsts: &'a [&'a [u8]]) -> Result<Self> + where + X: Digest<OutputSize = L>, + { + if dsts.is_empty() { + Err(Error) + } else if dsts.iter().map(|dst| dst.len()).sum::<usize>() > MAX_DST_LEN { + Ok(Self::Hashed({ + let mut hash = X::new(); + hash.update(OVERSIZE_DST_SALT); + + for dst in dsts { + hash.update(dst); + } + + hash.finalize() + })) + } else { + Ok(Self::Array(dsts)) + } + } + + pub fn update_hash<HashT: Update>(&self, hash: &mut HashT) { + match self { + Self::Hashed(d) => hash.update(d), + Self::Array(d) => { + for d in d.iter() { + hash.update(d) + } + } + } + } + + pub fn len(&self) -> u8 { + match self { + // Can't overflow because it's enforced on a type level. + Self::Hashed(_) => L::to_u8(), + // Can't overflow because it's checked on creation. + Self::Array(d) => { + u8::try_from(d.iter().map(|d| d.len()).sum::<usize>()).expect("length overflow") + } + } + } + + #[cfg(test)] + pub fn assert(&self, bytes: &[u8]) { + let data = match self { + Domain::Hashed(d) => d.to_vec(), + Domain::Array(d) => d.iter().copied().flatten().copied().collect(), + }; + assert_eq!(data, bytes); + } + + #[cfg(test)] + pub fn assert_dst(&self, bytes: &[u8]) { + let data = match self { + Domain::Hashed(d) => d.to_vec(), + Domain::Array(d) => d.iter().copied().flatten().copied().collect(), + }; + assert_eq!(data, &bytes[..bytes.len() - 1]); + assert_eq!(self.len(), bytes[bytes.len() - 1]); + } +} diff --git a/vendor/elliptic-curve/src/hash2curve/hash2field/expand_msg/xmd.rs b/vendor/elliptic-curve/src/hash2curve/hash2field/expand_msg/xmd.rs new file mode 100644 index 0000000..50edb64 --- /dev/null +++ b/vendor/elliptic-curve/src/hash2curve/hash2field/expand_msg/xmd.rs @@ -0,0 +1,453 @@ +//! `expand_message_xmd` based on a hash function. + +// TODO(tarcieri): checked arithmetic +#![allow(clippy::integer_arithmetic)] + +use core::marker::PhantomData; + +use super::{Domain, ExpandMsg, Expander}; +use crate::{Error, Result}; +use digest::{ + core_api::BlockSizeUser, + generic_array::{ + typenum::{IsLess, IsLessOrEqual, Unsigned, U256}, + GenericArray, + }, + FixedOutput, HashMarker, +}; + +/// Placeholder type for implementing `expand_message_xmd` based on a hash function +/// +/// # Errors +/// - `dst.is_empty()` +/// - `len_in_bytes == 0` +/// - `len_in_bytes > u16::MAX` +/// - `len_in_bytes > 255 * HashT::OutputSize` +pub struct ExpandMsgXmd<HashT>(PhantomData<HashT>) +where + HashT: BlockSizeUser + Default + FixedOutput + HashMarker, + HashT::OutputSize: IsLess<U256>, + HashT::OutputSize: IsLessOrEqual<HashT::BlockSize>; + +/// ExpandMsgXmd implements expand_message_xmd for the ExpandMsg trait +impl<'a, HashT> ExpandMsg<'a> for ExpandMsgXmd<HashT> +where + HashT: BlockSizeUser + Default + FixedOutput + HashMarker, + // If `len_in_bytes` is bigger then 256, length of the `DST` will depend on + // the output size of the hash, which is still not allowed to be bigger then 256: + // https://www.ietf.org/archive/id/draft-irtf-cfrg-hash-to-curve-13.html#section-5.4.1-6 + HashT::OutputSize: IsLess<U256>, + // Constraint set by `expand_message_xmd`: + // https://www.ietf.org/archive/id/draft-irtf-cfrg-hash-to-curve-13.html#section-5.4.1-4 + HashT::OutputSize: IsLessOrEqual<HashT::BlockSize>, +{ + type Expander = ExpanderXmd<'a, HashT>; + + fn expand_message( + msgs: &[&[u8]], + dsts: &'a [&'a [u8]], + len_in_bytes: usize, + ) -> Result<Self::Expander> { + if len_in_bytes == 0 { + return Err(Error); + } + + let len_in_bytes_u16 = u16::try_from(len_in_bytes).map_err(|_| Error)?; + + let b_in_bytes = HashT::OutputSize::to_usize(); + let ell = u8::try_from((len_in_bytes + b_in_bytes - 1) / b_in_bytes).map_err(|_| Error)?; + + let domain = Domain::xmd::<HashT>(dsts)?; + let mut b_0 = HashT::default(); + b_0.update(&GenericArray::<u8, HashT::BlockSize>::default()); + + for msg in msgs { + b_0.update(msg); + } + + b_0.update(&len_in_bytes_u16.to_be_bytes()); + b_0.update(&[0]); + domain.update_hash(&mut b_0); + b_0.update(&[domain.len()]); + let b_0 = b_0.finalize_fixed(); + + let mut b_vals = HashT::default(); + b_vals.update(&b_0[..]); + b_vals.update(&[1u8]); + domain.update_hash(&mut b_vals); + b_vals.update(&[domain.len()]); + let b_vals = b_vals.finalize_fixed(); + + Ok(ExpanderXmd { + b_0, + b_vals, + domain, + index: 1, + offset: 0, + ell, + }) + } +} + +/// [`Expander`] type for [`ExpandMsgXmd`]. +pub struct ExpanderXmd<'a, HashT> +where + HashT: BlockSizeUser + Default + FixedOutput + HashMarker, + HashT::OutputSize: IsLess<U256>, + HashT::OutputSize: IsLessOrEqual<HashT::BlockSize>, +{ + b_0: GenericArray<u8, HashT::OutputSize>, + b_vals: GenericArray<u8, HashT::OutputSize>, + domain: Domain<'a, HashT::OutputSize>, + index: u8, + offset: usize, + ell: u8, +} + +impl<'a, HashT> ExpanderXmd<'a, HashT> +where + HashT: BlockSizeUser + Default + FixedOutput + HashMarker, + HashT::OutputSize: IsLess<U256>, + HashT::OutputSize: IsLessOrEqual<HashT::BlockSize>, +{ + fn next(&mut self) -> bool { + if self.index < self.ell { + self.index += 1; + self.offset = 0; + // b_0 XOR b_(idx - 1) + let mut tmp = GenericArray::<u8, HashT::OutputSize>::default(); + self.b_0 + .iter() + .zip(&self.b_vals[..]) + .enumerate() + .for_each(|(j, (b0val, bi1val))| tmp[j] = b0val ^ bi1val); + let mut b_vals = HashT::default(); + b_vals.update(&tmp); + b_vals.update(&[self.index]); + self.domain.update_hash(&mut b_vals); + b_vals.update(&[self.domain.len()]); + self.b_vals = b_vals.finalize_fixed(); + true + } else { + false + } + } +} + +impl<'a, HashT> Expander for ExpanderXmd<'a, HashT> +where + HashT: BlockSizeUser + Default + FixedOutput + HashMarker, + HashT::OutputSize: IsLess<U256>, + HashT::OutputSize: IsLessOrEqual<HashT::BlockSize>, +{ + fn fill_bytes(&mut self, okm: &mut [u8]) { + for b in okm { + if self.offset == self.b_vals.len() && !self.next() { + return; + } + *b = self.b_vals[self.offset]; + self.offset += 1; + } + } +} + +#[cfg(test)] +mod test { + use super::*; + use core::mem; + use generic_array::{ + typenum::{U128, U32}, + ArrayLength, + }; + use hex_literal::hex; + use sha2::Sha256; + + fn assert_message<HashT>( + msg: &[u8], + domain: &Domain<'_, HashT::OutputSize>, + len_in_bytes: u16, + bytes: &[u8], + ) where + HashT: BlockSizeUser + Default + FixedOutput + HashMarker, + HashT::OutputSize: IsLess<U256>, + { + let block = HashT::BlockSize::to_usize(); + assert_eq!( + GenericArray::<u8, HashT::BlockSize>::default().as_slice(), + &bytes[..block] + ); + + let msg_len = block + msg.len(); + assert_eq!(msg, &bytes[block..msg_len]); + + let l = msg_len + mem::size_of::<u16>(); + assert_eq!(len_in_bytes.to_be_bytes(), &bytes[msg_len..l]); + + let pad = l + mem::size_of::<u8>(); + assert_eq!([0], &bytes[l..pad]); + + let dst = pad + usize::from(domain.len()); + domain.assert(&bytes[pad..dst]); + + let dst_len = dst + mem::size_of::<u8>(); + assert_eq!([domain.len()], &bytes[dst..dst_len]); + + assert_eq!(dst_len, bytes.len()); + } + + struct TestVector { + msg: &'static [u8], + msg_prime: &'static [u8], + uniform_bytes: &'static [u8], + } + + impl TestVector { + fn assert<HashT, L: ArrayLength<u8>>( + &self, + dst: &'static [u8], + domain: &Domain<'_, HashT::OutputSize>, + ) -> Result<()> + where + HashT: BlockSizeUser + Default + FixedOutput + HashMarker, + HashT::OutputSize: IsLess<U256> + IsLessOrEqual<HashT::BlockSize>, + { + assert_message::<HashT>(self.msg, domain, L::to_u16(), self.msg_prime); + + let dst = [dst]; + let mut expander = + ExpandMsgXmd::<HashT>::expand_message(&[self.msg], &dst, L::to_usize())?; + + let mut uniform_bytes = GenericArray::<u8, L>::default(); + expander.fill_bytes(&mut uniform_bytes); + + assert_eq!(uniform_bytes.as_slice(), self.uniform_bytes); + Ok(()) + } + } + + #[test] + fn expand_message_xmd_sha_256() -> Result<()> { + const DST: &[u8] = b"QUUX-V01-CS02-with-expander-SHA256-128"; + const DST_PRIME: &[u8] = + &hex!("515555582d5630312d435330322d776974682d657870616e6465722d5348413235362d31323826"); + + let dst_prime = Domain::xmd::<Sha256>(&[DST])?; + dst_prime.assert_dst(DST_PRIME); + + const TEST_VECTORS_32: &[TestVector] = &[ + TestVector { + msg: b"", + msg_prime: &hex!("00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000002000515555582d5630312d435330322d776974682d657870616e6465722d5348413235362d31323826"), + uniform_bytes: &hex!("68a985b87eb6b46952128911f2a4412bbc302a9d759667f87f7a21d803f07235"), + }, + TestVector { + msg: b"abc", + msg_prime: &hex!("00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000616263002000515555582d5630312d435330322d776974682d657870616e6465722d5348413235362d31323826"), + uniform_bytes: &hex!("d8ccab23b5985ccea865c6c97b6e5b8350e794e603b4b97902f53a8a0d605615"), + }, + TestVector { + msg: b"abcdef0123456789", + msg_prime: &hex!("0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000061626364656630313233343536373839002000515555582d5630312d435330322d776974682d657870616e6465722d5348413235362d31323826"), + uniform_bytes: &hex!("eff31487c770a893cfb36f912fbfcbff40d5661771ca4b2cb4eafe524333f5c1"), + }, + TestVector { + msg: b"q128_qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq", + msg_prime: &hex!("00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000713132385f7171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171002000515555582d5630312d435330322d776974682d657870616e6465722d5348413235362d31323826"), + uniform_bytes: &hex!("b23a1d2b4d97b2ef7785562a7e8bac7eed54ed6e97e29aa51bfe3f12ddad1ff9"), + }, + TestVector { + msg: b"a512_aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", + msg_prime: &hex!("00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000613531325f6161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161002000515555582d5630312d435330322d776974682d657870616e6465722d5348413235362d31323826"), + uniform_bytes: &hex!("4623227bcc01293b8c130bf771da8c298dede7383243dc0993d2d94823958c4c"), + }, + ]; + + for test_vector in TEST_VECTORS_32 { + test_vector.assert::<Sha256, U32>(DST, &dst_prime)?; + } + + const TEST_VECTORS_128: &[TestVector] = &[ + TestVector { + msg: b"", + msg_prime: &hex!("00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000008000515555582d5630312d435330322d776974682d657870616e6465722d5348413235362d31323826"), + uniform_bytes: &hex!("af84c27ccfd45d41914fdff5df25293e221afc53d8ad2ac06d5e3e29485dadbee0d121587713a3e0dd4d5e69e93eb7cd4f5df4cd103e188cf60cb02edc3edf18eda8576c412b18ffb658e3dd6ec849469b979d444cf7b26911a08e63cf31f9dcc541708d3491184472c2c29bb749d4286b004ceb5ee6b9a7fa5b646c993f0ced"), + }, TestVector { + msg: b"abc", + msg_prime: &hex!("00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000616263008000515555582d5630312d435330322d776974682d657870616e6465722d5348413235362d31323826"), + uniform_bytes: &hex!("abba86a6129e366fc877aab32fc4ffc70120d8996c88aee2fe4b32d6c7b6437a647e6c3163d40b76a73cf6a5674ef1d890f95b664ee0afa5359a5c4e07985635bbecbac65d747d3d2da7ec2b8221b17b0ca9dc8a1ac1c07ea6a1e60583e2cb00058e77b7b72a298425cd1b941ad4ec65e8afc50303a22c0f99b0509b4c895f40"), + }, TestVector { + msg: b"abcdef0123456789", + msg_prime: &hex!("0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000061626364656630313233343536373839008000515555582d5630312d435330322d776974682d657870616e6465722d5348413235362d31323826"), + uniform_bytes: &hex!("ef904a29bffc4cf9ee82832451c946ac3c8f8058ae97d8d629831a74c6572bd9ebd0df635cd1f208e2038e760c4994984ce73f0d55ea9f22af83ba4734569d4bc95e18350f740c07eef653cbb9f87910d833751825f0ebefa1abe5420bb52be14cf489b37fe1a72f7de2d10be453b2c9d9eb20c7e3f6edc5a60629178d9478df"), + }, TestVector { + msg: b"q128_qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq", + msg_prime: &hex!("00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000713132385f7171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171008000515555582d5630312d435330322d776974682d657870616e6465722d5348413235362d31323826"), + uniform_bytes: &hex!("80be107d0884f0d881bb460322f0443d38bd222db8bd0b0a5312a6fedb49c1bbd88fd75d8b9a09486c60123dfa1d73c1cc3169761b17476d3c6b7cbbd727acd0e2c942f4dd96ae3da5de368d26b32286e32de7e5a8cb2949f866a0b80c58116b29fa7fabb3ea7d520ee603e0c25bcaf0b9a5e92ec6a1fe4e0391d1cdbce8c68a"), + }, TestVector { + msg: b"a512_aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", + msg_prime: &hex!("00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000613531325f6161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161008000515555582d5630312d435330322d776974682d657870616e6465722d5348413235362d31323826"), + uniform_bytes: &hex!("546aff5444b5b79aa6148bd81728704c32decb73a3ba76e9e75885cad9def1d06d6792f8a7d12794e90efed817d96920d728896a4510864370c207f99bd4a608ea121700ef01ed879745ee3e4ceef777eda6d9e5e38b90c86ea6fb0b36504ba4a45d22e86f6db5dd43d98a294bebb9125d5b794e9d2a81181066eb954966a487"), + }, + ]; + + for test_vector in TEST_VECTORS_128 { + test_vector.assert::<Sha256, U128>(DST, &dst_prime)?; + } + + Ok(()) + } + + #[test] + fn expand_message_xmd_sha_256_long() -> Result<()> { + const DST: &[u8] = b"QUUX-V01-CS02-with-expander-SHA256-128-long-DST-1111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111"; + const DST_PRIME: &[u8] = + &hex!("412717974da474d0f8c420f320ff81e8432adb7c927d9bd082b4fb4d16c0a23620"); + + let dst_prime = Domain::xmd::<Sha256>(&[DST])?; + dst_prime.assert_dst(DST_PRIME); + + const TEST_VECTORS_32: &[TestVector] = &[ + TestVector { + msg: b"", + msg_prime: &hex!("00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000002000412717974da474d0f8c420f320ff81e8432adb7c927d9bd082b4fb4d16c0a23620"), + uniform_bytes: &hex!("e8dc0c8b686b7ef2074086fbdd2f30e3f8bfbd3bdf177f73f04b97ce618a3ed3"), + }, + TestVector { + msg: b"abc", + msg_prime: &hex!("00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000616263002000412717974da474d0f8c420f320ff81e8432adb7c927d9bd082b4fb4d16c0a23620"), + uniform_bytes: &hex!("52dbf4f36cf560fca57dedec2ad924ee9c266341d8f3d6afe5171733b16bbb12"), + }, + TestVector { + msg: b"abcdef0123456789", + msg_prime: &hex!("0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000061626364656630313233343536373839002000412717974da474d0f8c420f320ff81e8432adb7c927d9bd082b4fb4d16c0a23620"), + uniform_bytes: &hex!("35387dcf22618f3728e6c686490f8b431f76550b0b2c61cbc1ce7001536f4521"), + }, + TestVector { + msg: b"q128_qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq", + msg_prime: &hex!("00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000713132385f7171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171002000412717974da474d0f8c420f320ff81e8432adb7c927d9bd082b4fb4d16c0a23620"), + uniform_bytes: &hex!("01b637612bb18e840028be900a833a74414140dde0c4754c198532c3a0ba42bc"), + }, + TestVector { + msg: b"a512_aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", + msg_prime: &hex!("00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000613531325f6161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161002000412717974da474d0f8c420f320ff81e8432adb7c927d9bd082b4fb4d16c0a23620"), + uniform_bytes: &hex!("20cce7033cabc5460743180be6fa8aac5a103f56d481cf369a8accc0c374431b"), + }, + ]; + + for test_vector in TEST_VECTORS_32 { + test_vector.assert::<Sha256, U32>(DST, &dst_prime)?; + } + + const TEST_VECTORS_128: &[TestVector] = &[ + TestVector { + msg: b"", + msg_prime: &hex!("00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000008000412717974da474d0f8c420f320ff81e8432adb7c927d9bd082b4fb4d16c0a23620"), + uniform_bytes: &hex!("14604d85432c68b757e485c8894db3117992fc57e0e136f71ad987f789a0abc287c47876978e2388a02af86b1e8d1342e5ce4f7aaa07a87321e691f6fba7e0072eecc1218aebb89fb14a0662322d5edbd873f0eb35260145cd4e64f748c5dfe60567e126604bcab1a3ee2dc0778102ae8a5cfd1429ebc0fa6bf1a53c36f55dfc"), + }, + TestVector { + msg: b"abc", + msg_prime: &hex!("00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000616263008000412717974da474d0f8c420f320ff81e8432adb7c927d9bd082b4fb4d16c0a23620"), + uniform_bytes: &hex!("1a30a5e36fbdb87077552b9d18b9f0aee16e80181d5b951d0471d55b66684914aef87dbb3626eaabf5ded8cd0686567e503853e5c84c259ba0efc37f71c839da2129fe81afdaec7fbdc0ccd4c794727a17c0d20ff0ea55e1389d6982d1241cb8d165762dbc39fb0cee4474d2cbbd468a835ae5b2f20e4f959f56ab24cd6fe267"), + }, + TestVector { + msg: b"abcdef0123456789", + msg_prime: &hex!("0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000061626364656630313233343536373839008000412717974da474d0f8c420f320ff81e8432adb7c927d9bd082b4fb4d16c0a23620"), + uniform_bytes: &hex!("d2ecef3635d2397f34a9f86438d772db19ffe9924e28a1caf6f1c8f15603d4028f40891044e5c7e39ebb9b31339979ff33a4249206f67d4a1e7c765410bcd249ad78d407e303675918f20f26ce6d7027ed3774512ef5b00d816e51bfcc96c3539601fa48ef1c07e494bdc37054ba96ecb9dbd666417e3de289d4f424f502a982"), + }, + TestVector { + msg: b"q128_qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq", + msg_prime: &hex!("00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000713132385f7171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171008000412717974da474d0f8c420f320ff81e8432adb7c927d9bd082b4fb4d16c0a23620"), + uniform_bytes: &hex!("ed6e8c036df90111410431431a232d41a32c86e296c05d426e5f44e75b9a50d335b2412bc6c91e0a6dc131de09c43110d9180d0a70f0d6289cb4e43b05f7ee5e9b3f42a1fad0f31bac6a625b3b5c50e3a83316783b649e5ecc9d3b1d9471cb5024b7ccf40d41d1751a04ca0356548bc6e703fca02ab521b505e8e45600508d32"), + }, + TestVector { + msg: b"a512_aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", + msg_prime: &hex!("00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000613531325f6161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161008000412717974da474d0f8c420f320ff81e8432adb7c927d9bd082b4fb4d16c0a23620"), + uniform_bytes: &hex!("78b53f2413f3c688f07732c10e5ced29a17c6a16f717179ffbe38d92d6c9ec296502eb9889af83a1928cd162e845b0d3c5424e83280fed3d10cffb2f8431f14e7a23f4c68819d40617589e4c41169d0b56e0e3535be1fd71fbb08bb70c5b5ffed953d6c14bf7618b35fc1f4c4b30538236b4b08c9fbf90462447a8ada60be495"), + }, + ]; + + for test_vector in TEST_VECTORS_128 { + test_vector.assert::<Sha256, U128>(DST, &dst_prime)?; + } + + Ok(()) + } + + #[test] + fn expand_message_xmd_sha_512() -> Result<()> { + use sha2::Sha512; + + const DST: &[u8] = b"QUUX-V01-CS02-with-expander-SHA512-256"; + const DST_PRIME: &[u8] = + &hex!("515555582d5630312d435330322d776974682d657870616e6465722d5348413531322d32353626"); + + let dst_prime = Domain::xmd::<Sha512>(&[DST])?; + dst_prime.assert_dst(DST_PRIME); + + const TEST_VECTORS_32: &[TestVector] = &[ + TestVector { + msg: b"", + msg_prime: &hex!("0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000002000515555582d5630312d435330322d776974682d657870616e6465722d5348413531322d32353626"), + uniform_bytes: &hex!("6b9a7312411d92f921c6f68ca0b6380730a1a4d982c507211a90964c394179ba"), + }, + TestVector { + msg: b"abc", + msg_prime: &hex!("0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000616263002000515555582d5630312d435330322d776974682d657870616e6465722d5348413531322d32353626"), + uniform_bytes: &hex!("0da749f12fbe5483eb066a5f595055679b976e93abe9be6f0f6318bce7aca8dc"), + }, + TestVector { + msg: b"abcdef0123456789", + msg_prime: &hex!("000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000061626364656630313233343536373839002000515555582d5630312d435330322d776974682d657870616e6465722d5348413531322d32353626"), + uniform_bytes: &hex!("087e45a86e2939ee8b91100af1583c4938e0f5fc6c9db4b107b83346bc967f58"), + }, + TestVector { + msg: b"q128_qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq", + msg_prime: &hex!("0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000713132385f7171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171002000515555582d5630312d435330322d776974682d657870616e6465722d5348413531322d32353626"), + uniform_bytes: &hex!("7336234ee9983902440f6bc35b348352013becd88938d2afec44311caf8356b3"), + }, + TestVector { + msg: b"a512_aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", + msg_prime: &hex!("0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000613531325f6161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161002000515555582d5630312d435330322d776974682d657870616e6465722d5348413531322d32353626"), + uniform_bytes: &hex!("57b5f7e766d5be68a6bfe1768e3c2b7f1228b3e4b3134956dd73a59b954c66f4"), + }, + ]; + + for test_vector in TEST_VECTORS_32 { + test_vector.assert::<Sha512, U32>(DST, &dst_prime)?; + } + + const TEST_VECTORS_128: &[TestVector] = &[ + TestVector { + msg: b"", + msg_prime: &hex!("0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000008000515555582d5630312d435330322d776974682d657870616e6465722d5348413531322d32353626"), + uniform_bytes: &hex!("41b037d1734a5f8df225dd8c7de38f851efdb45c372887be655212d07251b921b052b62eaed99b46f72f2ef4cc96bfaf254ebbbec091e1a3b9e4fb5e5b619d2e0c5414800a1d882b62bb5cd1778f098b8eb6cb399d5d9d18f5d5842cf5d13d7eb00a7cff859b605da678b318bd0e65ebff70bec88c753b159a805d2c89c55961"), + }, + TestVector { + msg: b"abc", + msg_prime: &hex!("0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000616263008000515555582d5630312d435330322d776974682d657870616e6465722d5348413531322d32353626"), + uniform_bytes: &hex!("7f1dddd13c08b543f2e2037b14cefb255b44c83cc397c1786d975653e36a6b11bdd7732d8b38adb4a0edc26a0cef4bb45217135456e58fbca1703cd6032cb1347ee720b87972d63fbf232587043ed2901bce7f22610c0419751c065922b488431851041310ad659e4b23520e1772ab29dcdeb2002222a363f0c2b1c972b3efe1"), + }, + TestVector { + msg: b"abcdef0123456789", + msg_prime: &hex!("000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000061626364656630313233343536373839008000515555582d5630312d435330322d776974682d657870616e6465722d5348413531322d32353626"), + uniform_bytes: &hex!("3f721f208e6199fe903545abc26c837ce59ac6fa45733f1baaf0222f8b7acb0424814fcb5eecf6c1d38f06e9d0a6ccfbf85ae612ab8735dfdf9ce84c372a77c8f9e1c1e952c3a61b7567dd0693016af51d2745822663d0c2367e3f4f0bed827feecc2aaf98c949b5ed0d35c3f1023d64ad1407924288d366ea159f46287e61ac"), + }, + TestVector { + msg: b"q128_qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq", + msg_prime: &hex!("0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000713132385f7171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171008000515555582d5630312d435330322d776974682d657870616e6465722d5348413531322d32353626"), + uniform_bytes: &hex!("b799b045a58c8d2b4334cf54b78260b45eec544f9f2fb5bd12fb603eaee70db7317bf807c406e26373922b7b8920fa29142703dd52bdf280084fb7ef69da78afdf80b3586395b433dc66cde048a258e476a561e9deba7060af40adf30c64249ca7ddea79806ee5beb9a1422949471d267b21bc88e688e4014087a0b592b695ed"), + }, + TestVector { + msg: b"a512_aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", + msg_prime: &hex!("0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000613531325f6161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161008000515555582d5630312d435330322d776974682d657870616e6465722d5348413531322d32353626"), + uniform_bytes: &hex!("05b0bfef265dcee87654372777b7c44177e2ae4c13a27f103340d9cd11c86cb2426ffcad5bd964080c2aee97f03be1ca18e30a1f14e27bc11ebbd650f305269cc9fb1db08bf90bfc79b42a952b46daf810359e7bc36452684784a64952c343c52e5124cd1f71d474d5197fefc571a92929c9084ffe1112cf5eea5192ebff330b"), + }, + ]; + + for test_vector in TEST_VECTORS_128 { + test_vector.assert::<Sha512, U128>(DST, &dst_prime)?; + } + + Ok(()) + } +} diff --git a/vendor/elliptic-curve/src/hash2curve/hash2field/expand_msg/xof.rs b/vendor/elliptic-curve/src/hash2curve/hash2field/expand_msg/xof.rs new file mode 100644 index 0000000..9a5ff19 --- /dev/null +++ b/vendor/elliptic-curve/src/hash2curve/hash2field/expand_msg/xof.rs @@ -0,0 +1,352 @@ +//! `expand_message_xof` for the `ExpandMsg` trait + +use super::{Domain, ExpandMsg, Expander}; +use crate::{Error, Result}; +use digest::{ExtendableOutput, Update, XofReader}; +use generic_array::typenum::U32; + +/// Placeholder type for implementing `expand_message_xof` based on an extendable output function +/// +/// # Errors +/// - `dst.is_empty()` +/// - `len_in_bytes == 0` +/// - `len_in_bytes > u16::MAX` +pub struct ExpandMsgXof<HashT> +where + HashT: Default + ExtendableOutput + Update, +{ + reader: <HashT as ExtendableOutput>::Reader, +} + +/// ExpandMsgXof implements `expand_message_xof` for the [`ExpandMsg`] trait +impl<'a, HashT> ExpandMsg<'a> for ExpandMsgXof<HashT> +where + HashT: Default + ExtendableOutput + Update, +{ + type Expander = Self; + + fn expand_message( + msgs: &[&[u8]], + dsts: &'a [&'a [u8]], + len_in_bytes: usize, + ) -> Result<Self::Expander> { + if len_in_bytes == 0 { + return Err(Error); + } + + let len_in_bytes = u16::try_from(len_in_bytes).map_err(|_| Error)?; + + let domain = Domain::<U32>::xof::<HashT>(dsts)?; + let mut reader = HashT::default(); + + for msg in msgs { + reader = reader.chain(msg); + } + + reader.update(&len_in_bytes.to_be_bytes()); + domain.update_hash(&mut reader); + reader.update(&[domain.len()]); + let reader = reader.finalize_xof(); + Ok(Self { reader }) + } +} + +impl<HashT> Expander for ExpandMsgXof<HashT> +where + HashT: Default + ExtendableOutput + Update, +{ + fn fill_bytes(&mut self, okm: &mut [u8]) { + self.reader.read(okm); + } +} + +#[cfg(test)] +mod test { + use super::*; + use core::mem; + use generic_array::{ + typenum::{U128, U32}, + ArrayLength, GenericArray, + }; + use hex_literal::hex; + use sha3::Shake128; + + fn assert_message<HashT>( + msg: &[u8], + domain: &Domain<'_, U32>, + len_in_bytes: u16, + bytes: &[u8], + ) { + let msg_len = msg.len(); + assert_eq!(msg, &bytes[..msg_len]); + + let len_in_bytes_len = msg_len + mem::size_of::<u16>(); + assert_eq!( + len_in_bytes.to_be_bytes(), + &bytes[msg_len..len_in_bytes_len] + ); + + let dst = len_in_bytes_len + usize::from(domain.len()); + domain.assert(&bytes[len_in_bytes_len..dst]); + + let dst_len = dst + mem::size_of::<u8>(); + assert_eq!([domain.len()], &bytes[dst..dst_len]); + + assert_eq!(dst_len, bytes.len()); + } + + struct TestVector { + msg: &'static [u8], + msg_prime: &'static [u8], + uniform_bytes: &'static [u8], + } + + impl TestVector { + fn assert<HashT, L>(&self, dst: &'static [u8], domain: &Domain<'_, U32>) -> Result<()> + where + HashT: Default + ExtendableOutput + Update, + L: ArrayLength<u8>, + { + assert_message::<HashT>(self.msg, domain, L::to_u16(), self.msg_prime); + + let mut expander = + ExpandMsgXof::<HashT>::expand_message(&[self.msg], &[dst], L::to_usize())?; + + let mut uniform_bytes = GenericArray::<u8, L>::default(); + expander.fill_bytes(&mut uniform_bytes); + + assert_eq!(uniform_bytes.as_slice(), self.uniform_bytes); + Ok(()) + } + } + + #[test] + fn expand_message_xof_shake_128() -> Result<()> { + const DST: &[u8] = b"QUUX-V01-CS02-with-expander-SHAKE128"; + const DST_PRIME: &[u8] = + &hex!("515555582d5630312d435330322d776974682d657870616e6465722d5348414b4531323824"); + + let dst_prime = Domain::<U32>::xof::<Shake128>(&[DST])?; + dst_prime.assert_dst(DST_PRIME); + + const TEST_VECTORS_32: &[TestVector] = &[ + TestVector { + msg: b"", + msg_prime: &hex!("0020515555582d5630312d435330322d776974682d657870616e6465722d5348414b4531323824"), + uniform_bytes: &hex!("86518c9cd86581486e9485aa74ab35ba150d1c75c88e26b7043e44e2acd735a2"), + }, + TestVector { + msg: b"abc", + msg_prime: &hex!("6162630020515555582d5630312d435330322d776974682d657870616e6465722d5348414b4531323824"), + uniform_bytes: &hex!("8696af52a4d862417c0763556073f47bc9b9ba43c99b505305cb1ec04a9ab468"), + }, + TestVector { + msg: b"abcdef0123456789", + msg_prime: &hex!("616263646566303132333435363738390020515555582d5630312d435330322d776974682d657870616e6465722d5348414b4531323824"), + uniform_bytes: &hex!("912c58deac4821c3509dbefa094df54b34b8f5d01a191d1d3108a2c89077acca"), + }, + TestVector { + msg: b"q128_qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq", + msg_prime: &hex!("713132385f71717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171710020515555582d5630312d435330322d776974682d657870616e6465722d5348414b4531323824"), + uniform_bytes: &hex!("1adbcc448aef2a0cebc71dac9f756b22e51839d348e031e63b33ebb50faeaf3f"), + }, + TestVector { + msg: b"a512_aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", + msg_prime: &hex!("613531325f61616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161610020515555582d5630312d435330322d776974682d657870616e6465722d5348414b4531323824"), + uniform_bytes: &hex!("df3447cc5f3e9a77da10f819218ddf31342c310778e0e4ef72bbaecee786a4fe"), + }, + ]; + + for test_vector in TEST_VECTORS_32 { + test_vector.assert::<Shake128, U32>(DST, &dst_prime)?; + } + + const TEST_VECTORS_128: &[TestVector] = &[ + TestVector { + msg: b"", + msg_prime: &hex!("0080515555582d5630312d435330322d776974682d657870616e6465722d5348414b4531323824"), + uniform_bytes: &hex!("7314ff1a155a2fb99a0171dc71b89ab6e3b2b7d59e38e64419b8b6294d03ffee42491f11370261f436220ef787f8f76f5b26bdcd850071920ce023f3ac46847744f4612b8714db8f5db83205b2e625d95afd7d7b4d3094d3bdde815f52850bb41ead9822e08f22cf41d615a303b0d9dde73263c049a7b9898208003a739a2e57"), + }, + TestVector { + msg: b"abc", + msg_prime: &hex!("6162630080515555582d5630312d435330322d776974682d657870616e6465722d5348414b4531323824"), + uniform_bytes: &hex!("c952f0c8e529ca8824acc6a4cab0e782fc3648c563ddb00da7399f2ae35654f4860ec671db2356ba7baa55a34a9d7f79197b60ddae6e64768a37d699a78323496db3878c8d64d909d0f8a7de4927dcab0d3dbbc26cb20a49eceb0530b431cdf47bc8c0fa3e0d88f53b318b6739fbed7d7634974f1b5c386d6230c76260d5337a"), + }, + TestVector { + msg: b"abcdef0123456789", + msg_prime: &hex!("616263646566303132333435363738390080515555582d5630312d435330322d776974682d657870616e6465722d5348414b4531323824"), + uniform_bytes: &hex!("19b65ee7afec6ac06a144f2d6134f08eeec185f1a890fe34e68f0e377b7d0312883c048d9b8a1d6ecc3b541cb4987c26f45e0c82691ea299b5e6889bbfe589153016d8131717ba26f07c3c14ffbef1f3eff9752e5b6183f43871a78219a75e7000fbac6a7072e2b83c790a3a5aecd9d14be79f9fd4fb180960a3772e08680495"), + }, + TestVector { + msg: b"q128_qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq", + msg_prime: &hex!("713132385f71717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171710080515555582d5630312d435330322d776974682d657870616e6465722d5348414b4531323824"), + uniform_bytes: &hex!("ca1b56861482b16eae0f4a26212112362fcc2d76dcc80c93c4182ed66c5113fe41733ed68be2942a3487394317f3379856f4822a611735e50528a60e7ade8ec8c71670fec6661e2c59a09ed36386513221688b35dc47e3c3111ee8c67ff49579089d661caa29db1ef10eb6eace575bf3dc9806e7c4016bd50f3c0e2a6481ee6d"), + }, + TestVector { + msg: b"a512_aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", + msg_prime: &hex!("613531325f61616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161610080515555582d5630312d435330322d776974682d657870616e6465722d5348414b4531323824"), + uniform_bytes: &hex!("9d763a5ce58f65c91531b4100c7266d479a5d9777ba761693d052acd37d149e7ac91c796a10b919cd74a591a1e38719fb91b7203e2af31eac3bff7ead2c195af7d88b8bc0a8adf3d1e90ab9bed6ddc2b7f655dd86c730bdeaea884e73741097142c92f0e3fc1811b699ba593c7fbd81da288a29d423df831652e3a01a9374999"), + }, + ]; + + for test_vector in TEST_VECTORS_128 { + test_vector.assert::<Shake128, U128>(DST, &dst_prime)?; + } + + Ok(()) + } + + #[test] + fn expand_message_xof_shake_128_long() -> Result<()> { + const DST: &[u8] = b"QUUX-V01-CS02-with-expander-SHAKE128-long-DST-111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111"; + const DST_PRIME: &[u8] = + &hex!("acb9736c0867fdfbd6385519b90fc8c034b5af04a958973212950132d035792f20"); + + let dst_prime = Domain::<U32>::xof::<Shake128>(&[DST])?; + dst_prime.assert_dst(DST_PRIME); + + const TEST_VECTORS_32: &[TestVector] = &[ + TestVector { + msg: b"", + msg_prime: &hex!("0020acb9736c0867fdfbd6385519b90fc8c034b5af04a958973212950132d035792f20"), + uniform_bytes: &hex!("827c6216330a122352312bccc0c8d6e7a146c5257a776dbd9ad9d75cd880fc53"), + }, + TestVector { + msg: b"abc", + msg_prime: &hex!("6162630020acb9736c0867fdfbd6385519b90fc8c034b5af04a958973212950132d035792f20"), + uniform_bytes: &hex!("690c8d82c7213b4282c6cb41c00e31ea1d3e2005f93ad19bbf6da40f15790c5c"), + }, + TestVector { + msg: b"abcdef0123456789", + msg_prime: &hex!("616263646566303132333435363738390020acb9736c0867fdfbd6385519b90fc8c034b5af04a958973212950132d035792f20"), + uniform_bytes: &hex!("979e3a15064afbbcf99f62cc09fa9c85028afcf3f825eb0711894dcfc2f57057"), + }, + TestVector { + msg: b"q128_qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq", + msg_prime: &hex!("713132385f71717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171710020acb9736c0867fdfbd6385519b90fc8c034b5af04a958973212950132d035792f20"), + uniform_bytes: &hex!("c5a9220962d9edc212c063f4f65b609755a1ed96e62f9db5d1fd6adb5a8dc52b"), + }, + TestVector { + msg: b"a512_aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", + msg_prime: &hex!("613531325f61616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161610020acb9736c0867fdfbd6385519b90fc8c034b5af04a958973212950132d035792f20"), + uniform_bytes: &hex!("f7b96a5901af5d78ce1d071d9c383cac66a1dfadb508300ec6aeaea0d62d5d62"), + }, + ]; + + for test_vector in TEST_VECTORS_32 { + test_vector.assert::<Shake128, U32>(DST, &dst_prime)?; + } + + const TEST_VECTORS_128: &[TestVector] = &[ + TestVector { + msg: b"", + msg_prime: &hex!("0080acb9736c0867fdfbd6385519b90fc8c034b5af04a958973212950132d035792f20"), + uniform_bytes: &hex!("3890dbab00a2830be398524b71c2713bbef5f4884ac2e6f070b092effdb19208c7df943dc5dcbaee3094a78c267ef276632ee2c8ea0c05363c94b6348500fae4208345dd3475fe0c834c2beac7fa7bc181692fb728c0a53d809fc8111495222ce0f38468b11becb15b32060218e285c57a60162c2c8bb5b6bded13973cd41819"), + }, + TestVector { + msg: b"abc", + msg_prime: &hex!("6162630080acb9736c0867fdfbd6385519b90fc8c034b5af04a958973212950132d035792f20"), + uniform_bytes: &hex!("41b7ffa7a301b5c1441495ebb9774e2a53dbbf4e54b9a1af6a20fd41eafd69ef7b9418599c5545b1ee422f363642b01d4a53449313f68da3e49dddb9cd25b97465170537d45dcbdf92391b5bdff344db4bd06311a05bca7dcd360b6caec849c299133e5c9194f4e15e3e23cfaab4003fab776f6ac0bfae9144c6e2e1c62e7d57"), + }, + TestVector { + msg: b"abcdef0123456789", + msg_prime: &hex!("616263646566303132333435363738390080acb9736c0867fdfbd6385519b90fc8c034b5af04a958973212950132d035792f20"), + uniform_bytes: &hex!("55317e4a21318472cd2290c3082957e1242241d9e0d04f47026f03401643131401071f01aa03038b2783e795bdfa8a3541c194ad5de7cb9c225133e24af6c86e748deb52e560569bd54ef4dac03465111a3a44b0ea490fb36777ff8ea9f1a8a3e8e0de3cf0880b4b2f8dd37d3a85a8b82375aee4fa0e909f9763319b55778e71"), + }, + TestVector { + msg: b"q128_qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq", + msg_prime: &hex!("713132385f71717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171710080acb9736c0867fdfbd6385519b90fc8c034b5af04a958973212950132d035792f20"), + uniform_bytes: &hex!("19fdd2639f082e31c77717ac9bb032a22ff0958382b2dbb39020cdc78f0da43305414806abf9a561cb2d0067eb2f7bc544482f75623438ed4b4e39dd9e6e2909dd858bd8f1d57cd0fce2d3150d90aa67b4498bdf2df98c0100dd1a173436ba5d0df6be1defb0b2ce55ccd2f4fc05eb7cb2c019c35d5398b85adc676da4238bc7"), + }, + TestVector { + msg: b"a512_aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", + msg_prime: &hex!("613531325f61616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161610080acb9736c0867fdfbd6385519b90fc8c034b5af04a958973212950132d035792f20"), + uniform_bytes: &hex!("945373f0b3431a103333ba6a0a34f1efab2702efde41754c4cb1d5216d5b0a92a67458d968562bde7fa6310a83f53dda1383680a276a283438d58ceebfa7ab7ba72499d4a3eddc860595f63c93b1c5e823ea41fc490d938398a26db28f61857698553e93f0574eb8c5017bfed6249491f9976aaa8d23d9485339cc85ca329308"), + }, + ]; + + for test_vector in TEST_VECTORS_128 { + test_vector.assert::<Shake128, U128>(DST, &dst_prime)?; + } + + Ok(()) + } + + #[test] + fn expand_message_xof_shake_256() -> Result<()> { + use sha3::Shake256; + + const DST: &[u8] = b"QUUX-V01-CS02-with-expander-SHAKE256"; + const DST_PRIME: &[u8] = + &hex!("515555582d5630312d435330322d776974682d657870616e6465722d5348414b4532353624"); + + let dst_prime = Domain::<U32>::xof::<Shake256>(&[DST])?; + dst_prime.assert_dst(DST_PRIME); + + const TEST_VECTORS_32: &[TestVector] = &[ + TestVector { + msg: b"", + msg_prime: &hex!("0020515555582d5630312d435330322d776974682d657870616e6465722d5348414b4532353624"), + uniform_bytes: &hex!("2ffc05c48ed32b95d72e807f6eab9f7530dd1c2f013914c8fed38c5ccc15ad76"), + }, + TestVector { + msg: b"abc", + msg_prime: &hex!("6162630020515555582d5630312d435330322d776974682d657870616e6465722d5348414b4532353624"), + uniform_bytes: &hex!("b39e493867e2767216792abce1f2676c197c0692aed061560ead251821808e07"), + }, + TestVector { + msg: b"abcdef0123456789", + msg_prime: &hex!("616263646566303132333435363738390020515555582d5630312d435330322d776974682d657870616e6465722d5348414b4532353624"), + uniform_bytes: &hex!("245389cf44a13f0e70af8665fe5337ec2dcd138890bb7901c4ad9cfceb054b65"), + }, + TestVector { + msg: b"q128_qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq", + msg_prime: &hex!("713132385f71717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171710020515555582d5630312d435330322d776974682d657870616e6465722d5348414b4532353624"), + uniform_bytes: &hex!("719b3911821e6428a5ed9b8e600f2866bcf23c8f0515e52d6c6c019a03f16f0e"), + }, + TestVector { + msg: b"a512_aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", + msg_prime: &hex!("613531325f61616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161610020515555582d5630312d435330322d776974682d657870616e6465722d5348414b4532353624"), + uniform_bytes: &hex!("9181ead5220b1963f1b5951f35547a5ea86a820562287d6ca4723633d17ccbbc"), + }, + ]; + + for test_vector in TEST_VECTORS_32 { + test_vector.assert::<Shake256, U32>(DST, &dst_prime)?; + } + + const TEST_VECTORS_128: &[TestVector] = &[ + TestVector { + msg: b"", + msg_prime: &hex!("0080515555582d5630312d435330322d776974682d657870616e6465722d5348414b4532353624"), + uniform_bytes: &hex!("7a1361d2d7d82d79e035b8880c5a3c86c5afa719478c007d96e6c88737a3f631dd74a2c88df79a4cb5e5d9f7504957c70d669ec6bfedc31e01e2bacc4ff3fdf9b6a00b17cc18d9d72ace7d6b81c2e481b4f73f34f9a7505dccbe8f5485f3d20c5409b0310093d5d6492dea4e18aa6979c23c8ea5de01582e9689612afbb353df"), + }, + TestVector { + msg: b"abc", + msg_prime: &hex!("6162630080515555582d5630312d435330322d776974682d657870616e6465722d5348414b4532353624"), + uniform_bytes: &hex!("a54303e6b172909783353ab05ef08dd435a558c3197db0c132134649708e0b9b4e34fb99b92a9e9e28fc1f1d8860d85897a8e021e6382f3eea10577f968ff6df6c45fe624ce65ca25932f679a42a404bc3681efe03fcd45ef73bb3a8f79ba784f80f55ea8a3c367408f30381299617f50c8cf8fbb21d0f1e1d70b0131a7b6fbe"), + }, + TestVector { + msg: b"abcdef0123456789", + msg_prime: &hex!("616263646566303132333435363738390080515555582d5630312d435330322d776974682d657870616e6465722d5348414b4532353624"), + uniform_bytes: &hex!("e42e4d9538a189316e3154b821c1bafb390f78b2f010ea404e6ac063deb8c0852fcd412e098e231e43427bd2be1330bb47b4039ad57b30ae1fc94e34993b162ff4d695e42d59d9777ea18d3848d9d336c25d2acb93adcad009bcfb9cde12286df267ada283063de0bb1505565b2eb6c90e31c48798ecdc71a71756a9110ff373"), + }, + TestVector { + msg: b"q128_qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq", + msg_prime: &hex!("713132385f71717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171717171710080515555582d5630312d435330322d776974682d657870616e6465722d5348414b4532353624"), + uniform_bytes: &hex!("4ac054dda0a38a65d0ecf7afd3c2812300027c8789655e47aecf1ecc1a2426b17444c7482c99e5907afd9c25b991990490bb9c686f43e79b4471a23a703d4b02f23c669737a886a7ec28bddb92c3a98de63ebf878aa363a501a60055c048bea11840c4717beae7eee28c3cfa42857b3d130188571943a7bd747de831bd6444e0"), + }, + TestVector { + msg: b"a512_aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", + msg_prime: &hex!("613531325f61616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161616161610080515555582d5630312d435330322d776974682d657870616e6465722d5348414b4532353624"), + uniform_bytes: &hex!("09afc76d51c2cccbc129c2315df66c2be7295a231203b8ab2dd7f95c2772c68e500bc72e20c602abc9964663b7a03a389be128c56971ce81001a0b875e7fd17822db9d69792ddf6a23a151bf470079c518279aef3e75611f8f828994a9988f4a8a256ddb8bae161e658d5a2a09bcfe839c6396dc06ee5c8ff3c22d3b1f9deb7e"), + }, + ]; + + for test_vector in TEST_VECTORS_128 { + test_vector.assert::<Shake256, U128>(DST, &dst_prime)?; + } + + Ok(()) + } +} diff --git a/vendor/elliptic-curve/src/hash2curve/isogeny.rs b/vendor/elliptic-curve/src/hash2curve/isogeny.rs new file mode 100644 index 0000000..7a28983 --- /dev/null +++ b/vendor/elliptic-curve/src/hash2curve/isogeny.rs @@ -0,0 +1,58 @@ +//! Traits for mapping an isogeny to another curve +//! +//! <https://datatracker.ietf.org/doc/draft-irtf-cfrg-hash-to-curve> + +use core::ops::{AddAssign, Mul}; +use ff::Field; +use generic_array::{typenum::Unsigned, ArrayLength, GenericArray}; + +/// The coefficients for mapping from one isogenous curve to another +pub struct IsogenyCoefficients<F: Field + AddAssign + Mul<Output = F>> { + /// The coefficients for the x numerator + pub xnum: &'static [F], + /// The coefficients for the x denominator + pub xden: &'static [F], + /// The coefficients for the y numerator + pub ynum: &'static [F], + /// The coefficients for the x denominator + pub yden: &'static [F], +} + +/// The [`Isogeny`] methods to map to another curve. +pub trait Isogeny: Field + AddAssign + Mul<Output = Self> { + /// The maximum number of coefficients + type Degree: ArrayLength<Self>; + /// The isogeny coefficients + const COEFFICIENTS: IsogenyCoefficients<Self>; + + /// Map from the isogeny points to the main curve + #[allow(clippy::integer_arithmetic)] + fn isogeny(x: Self, y: Self) -> (Self, Self) { + let mut xs = GenericArray::<Self, Self::Degree>::default(); + xs[0] = Self::ONE; + xs[1] = x; + xs[2] = x.square(); + for i in 3..Self::Degree::to_usize() { + xs[i] = xs[i - 1] * x; + } + let x_num = Self::compute_iso(&xs, Self::COEFFICIENTS.xnum); + let x_den = Self::compute_iso(&xs, Self::COEFFICIENTS.xden) + .invert() + .unwrap(); + let y_num = Self::compute_iso(&xs, Self::COEFFICIENTS.ynum) * y; + let y_den = Self::compute_iso(&xs, Self::COEFFICIENTS.yden) + .invert() + .unwrap(); + + (x_num * x_den, y_num * y_den) + } + + /// Compute the ISO transform + fn compute_iso(xxs: &[Self], k: &[Self]) -> Self { + let mut xx = Self::ZERO; + for (xi, ki) in xxs.iter().zip(k.iter()) { + xx += *xi * ki; + } + xx + } +} diff --git a/vendor/elliptic-curve/src/hash2curve/map2curve.rs b/vendor/elliptic-curve/src/hash2curve/map2curve.rs new file mode 100644 index 0000000..6092e57 --- /dev/null +++ b/vendor/elliptic-curve/src/hash2curve/map2curve.rs @@ -0,0 +1,12 @@ +//! Traits for mapping field elements to points on the curve. + +/// Trait for converting field elements into a point +/// via a mapping method like Simplified Shallue-van de Woestijne-Ulas +/// or Elligator +pub trait MapToCurve { + /// The output point + type Output; + + /// Map a field element into a point + fn map_to_curve(&self) -> Self::Output; +} diff --git a/vendor/elliptic-curve/src/hash2curve/osswu.rs b/vendor/elliptic-curve/src/hash2curve/osswu.rs new file mode 100644 index 0000000..3c3669a --- /dev/null +++ b/vendor/elliptic-curve/src/hash2curve/osswu.rs @@ -0,0 +1,130 @@ +//! Optimized simplified Shallue-van de Woestijne-Ulas methods. +//! +//! <https://www.ietf.org/archive/id/draft-irtf-cfrg-hash-to-curve-16.html#straightline-sswu> + +use ff::Field; +use subtle::Choice; +use subtle::ConditionallySelectable; +use subtle::ConstantTimeEq; + +/// The Optimized Simplified Shallue-van de Woestijne-Ulas parameters +pub struct OsswuMapParams<F> +where + F: Field, +{ + /// The first constant term + pub c1: &'static [u64], + /// The second constant term + pub c2: F, + /// The ISO A variable or Curve A variable + pub map_a: F, + /// The ISO A variable or Curve A variable + pub map_b: F, + /// The Z parameter + pub z: F, +} + +/// Trait for determining the parity of the field +pub trait Sgn0 { + /// Return the parity of the field + /// 1 == negative + /// 0 == non-negative + fn sgn0(&self) -> Choice; +} + +/// The optimized simplified Shallue-van de Woestijne-Ulas method +/// for mapping elliptic curve scalars to affine points. +pub trait OsswuMap: Field + Sgn0 { + /// The OSSWU parameters for mapping the field to affine points. + /// For Weierstrass curves having A==0 or B==0, the parameters + /// should be for isogeny where A≠0 and B≠0. + const PARAMS: OsswuMapParams<Self>; + + /// Optimized sqrt_ratio for q = 3 mod 4. + fn sqrt_ratio_3mod4(u: Self, v: Self) -> (Choice, Self) { + // 1. tv1 = v^2 + let tv1 = v.square(); + // 2. tv2 = u * v + let tv2 = u * v; + // 3. tv1 = tv1 * tv2 + let tv1 = tv1 * tv2; + // 4. y1 = tv1^c1 + let y1 = tv1.pow_vartime(Self::PARAMS.c1); + // 5. y1 = y1 * tv2 + let y1 = y1 * tv2; + // 6. y2 = y1 * c2 + let y2 = y1 * Self::PARAMS.c2; + // 7. tv3 = y1^2 + let tv3 = y1.square(); + // 8. tv3 = tv3 * v + let tv3 = tv3 * v; + // 9. isQR = tv3 == u + let is_qr = tv3.ct_eq(&u); + // 10. y = CMOV(y2, y1, isQR) + let y = ConditionallySelectable::conditional_select(&y2, &y1, is_qr); + // 11. return (isQR, y) + (is_qr, y) + } + + /// Convert this field element into an affine point on the elliptic curve + /// returning (X, Y). For Weierstrass curves having A==0 or B==0 + /// the result is a point on an isogeny. + fn osswu(&self) -> (Self, Self) { + // 1. tv1 = u^2 + let tv1 = self.square(); + // 2. tv1 = Z * tv1 + let tv1 = Self::PARAMS.z * tv1; + // 3. tv2 = tv1^2 + let tv2 = tv1.square(); + // 4. tv2 = tv2 + tv1 + let tv2 = tv2 + tv1; + // 5. tv3 = tv2 + 1 + let tv3 = tv2 + Self::ONE; + // 6. tv3 = B * tv3 + let tv3 = Self::PARAMS.map_b * tv3; + // 7. tv4 = CMOV(Z, -tv2, tv2 != 0) + let tv4 = ConditionallySelectable::conditional_select( + &Self::PARAMS.z, + &-tv2, + !Field::is_zero(&tv2), + ); + // 8. tv4 = A * tv4 + let tv4 = Self::PARAMS.map_a * tv4; + // 9. tv2 = tv3^2 + let tv2 = tv3.square(); + // 10. tv6 = tv4^2 + let tv6 = tv4.square(); + // 11. tv5 = A * tv6 + let tv5 = Self::PARAMS.map_a * tv6; + // 12. tv2 = tv2 + tv5 + let tv2 = tv2 + tv5; + // 13. tv2 = tv2 * tv3 + let tv2 = tv2 * tv3; + // 14. tv6 = tv6 * tv4 + let tv6 = tv6 * tv4; + // 15. tv5 = B * tv6 + let tv5 = Self::PARAMS.map_b * tv6; + // 16. tv2 = tv2 + tv5 + let tv2 = tv2 + tv5; + // 17. x = tv1 * tv3 + let x = tv1 * tv3; + // 18. (is_gx1_square, y1) = sqrt_ratio(tv2, tv6) + let (is_gx1_square, y1) = Self::sqrt_ratio_3mod4(tv2, tv6); + // 19. y = tv1 * u + let y = tv1 * self; + // 20. y = y * y1 + let y = y * y1; + // 21. x = CMOV(x, tv3, is_gx1_square) + let x = ConditionallySelectable::conditional_select(&x, &tv3, is_gx1_square); + // 22. y = CMOV(y, y1, is_gx1_square) + let y = ConditionallySelectable::conditional_select(&y, &y1, is_gx1_square); + // 23. e1 = sgn0(u) == sgn0(y) + let e1 = self.sgn0().ct_eq(&y.sgn0()); + // 24. y = CMOV(-y, y, e1) + let y = ConditionallySelectable::conditional_select(&-y, &y, e1); + // 25. x = x / tv4 + let x = x * tv4.invert().unwrap(); + // 26. return (x, y) + (x, y) + } +} |