feat: bump MSRV to 1.81, make all crates no_std

.github/workflows/main.yml

@@ -25,7 +25,7 @@ jobs:
           command: build
 
   build_msrv:
-    name: build with MSRV (1.66.1)
+    name: build with MSRV (1.81)
     runs-on: ubuntu-latest
 
     steps:
@@ -40,7 +40,7 @@ jobs:
       - run: cargo update -Z minimal-versions
       # Now check that `cargo build` works with respect to the oldest possible
       # deps and the stated MSRV
-      - uses: dtolnay/rust-toolchain@1.66.1
+      - uses: dtolnay/rust-toolchain@1.81
       - run: cargo build --all-features
 
   # TODO: this is filling up the disk space in CI. See if there is a way to
@@ -66,10 +66,9 @@ jobs:
   build_no_std:
     name: build with no_std
     runs-on: ubuntu-latest
-    # Skip ed448 which does not support it.
     strategy:
       matrix:
-        crate: [ristretto255, ed25519, p256, secp256k1, rerandomized]
+        crate: [ed448, ristretto255, ed25519, p256, secp256k1, rerandomized]
     steps:
     - uses: actions/[email protected]
     - uses: dtolnay/rust-toolchain@master

frost-core/CHANGELOG.md

@@ -7,6 +7,10 @@ Entries are listed in reverse chronological order.
 * It is now possible to identify the culprit in `frost_core::keys::dkg::part3()`
   if an invalid secret share was sent by one of the participants (by calling
   frost_core::Error<C>::culprit()`).
+* Added no-std support for frost-ed448 crate. This became possible after migration to `ed448-goldilocks-plus` (fork of
+  `ed448-goldilocks`).
+* MSRV has been bumped to Rust 1.81, making all crates no-std. The `std` and `nightly` features were removed from all
+  crates.
 
 ## 2.0.0
 

frost-core/Cargo.toml

@@ -16,6 +16,7 @@ repository = "https://github.com/ZcashFoundation/frost"
 categories = ["cryptography"]
 keywords = ["cryptography", "crypto", "threshold", "signature", "schnorr"]
 description = "Types and traits to support implementing Flexible Round-Optimized Schnorr Threshold signature schemes (FROST)."
+rust-version = "1.81"
 
 [package.metadata.docs.rs]
 features = ["serde"]
@@ -32,8 +33,7 @@ postcard = { version = "1.0.0", features = ["alloc"], optional = true }
 rand_core = { version = "0.6", default-features = false }
 serde = { version = "1.0.160", default-features = false, features = ["derive"], optional = true }
 serdect = { version = "0.2.0", optional = true }
-thiserror-nostd-notrait = { version = "1.0.29", default-features = false }
-thiserror = { version = "1.0.29", default-features = false, optional = true }
+thiserror = { version = "2", default-features = false }
 visibility = "0.1.0"
 zeroize = { version = "1.5.4", default-features = false, features = ["derive"] }
 itertools = { version = "0.13.0", default-features = false }
@@ -52,10 +52,7 @@ rand_chacha = "0.3"
 serde_json = "1.0"
 
 [features]
-default = ["serialization", "cheater-detection", "std"]
-#! ## Features
-## Enable standard library support.
-std = ["dep:thiserror"]
+default = ["serialization", "cheater-detection"]
 ## Expose internal types, which do not have SemVer guarantees. This is an advanced
 ## feature which can be useful if you need to build a modified version of FROST.
 ## The docs won't list them, you will need to check the source code.

frost-core/src/error.rs

@@ -1,12 +1,7 @@
 //! FROST Error types
 
-#[cfg(feature = "std")]
-use thiserror::Error;
-
-#[cfg(not(feature = "std"))]
-use thiserror_nostd_notrait::Error;
-
 use crate::{Ciphersuite, Identifier};
+use thiserror::Error;
 
 #[derive(Error, Debug, Clone, Copy, Eq, PartialEq)]
 pub struct ParticipantError<C: Ciphersuite>(Identifier<C>);

frost-core/src/lib.rs

@@ -1,4 +1,4 @@
-#![cfg_attr(not(feature = "std"), no_std)]
+#![no_std]
 #![allow(non_snake_case)]
 // It's emitting false positives; see https://github.com/rust-lang/rust-clippy/issues/9413
 #![allow(clippy::derive_partial_eq_without_eq)]

frost-core/src/scalar_mul.rs

@@ -14,27 +14,6 @@ use alloc::vec::Vec;
 
 use crate::{Ciphersuite, Element, Field, Group, Scalar};
 
-/// Calculates the quotient of `self` and `rhs`, rounding the result towards positive infinity.
-///
-/// # Panics
-///
-/// This function will panic if `rhs` is 0 or the division results in overflow.
-///
-/// This function is similar to `div_ceil` that is [available on
-/// Nightly](https://github.com/rust-lang/rust/issues/88581).
-///
-// TODO: remove this function and use `div_ceil()` instead when `int_roundings`
-// is stabilized.
-const fn div_ceil(lhs: usize, rhs: usize) -> usize {
-    let d = lhs / rhs;
-    let r = lhs % rhs;
-    if r > 0 && rhs > 0 {
-        d + 1
-    } else {
-        d
-    }
-}
-
 /// A trait for transforming a scalar generic over a ciphersuite to a non-adjacent form (NAF).
 pub trait NonAdjacentForm<C: Ciphersuite> {
     fn non_adjacent_form(&self, w: usize) -> Vec<i8>;
@@ -81,7 +60,7 @@ where
         let mut naf = vec![0; naf_length];
 
         // Get the number of 64-bit limbs we need.
-        let num_limbs: usize = div_ceil(naf_length, u64::BITS as usize);
+        let num_limbs: usize = naf_length.div_ceil(u64::BITS as usize);
 
         let mut x_u64 = vec![0u64; num_limbs];
 

frost-core/src/tests/refresh.rs

@@ -1,6 +1,6 @@
 //! Test for Refreshing shares
 
-use std::collections::BTreeMap;
+use alloc::collections::BTreeMap;
 
 use rand_core::{CryptoRng, RngCore};
 

frost-ed25519/Cargo.toml

@@ -17,6 +17,7 @@ repository = "https://github.com/ZcashFoundation/frost"
 categories = ["cryptography"]
 keywords = ["cryptography", "crypto", "ed25519", "threshold", "signature"]
 description = "A Schnorr signature scheme over Ed25519 that supports FROST."
+rust-version = "1.81"
 
 [package.metadata.docs.rs]
 features = ["serde"]
@@ -44,11 +45,7 @@ rand_chacha = "0.3"
 serde_json = "1.0"
 
 [features]
-nightly = []
-default = ["serialization", "cheater-detection", "std"]
-#! ## Features
-## Enable standard library support.
-std = ["frost-core/std"]
+default = ["serialization", "cheater-detection"]
 ## Enable `serde` support for types that need to be communicated. You
 ## can use `serde` to serialize structs with any encoder that supports
 ## `serde` (e.g. JSON with `serde_json`).

frost-ed25519/src/lib.rs

@@ -1,4 +1,4 @@
-#![cfg_attr(not(feature = "std"), no_std)]
+#![no_std]
 #![allow(non_snake_case)]
 #![deny(missing_docs)]
 #![cfg_attr(docsrs, feature(doc_auto_cfg))]

frost-ed448/Cargo.toml

@@ -16,14 +16,15 @@ repository = "https://github.com/ZcashFoundation/frost"
 categories = ["cryptography"]
 keywords = ["cryptography", "crypto", "ed448", "threshold", "signature"]
 description = "A Schnorr signature scheme over Ed448 that supports FROST."
+rust-version = "1.81"
 
 [package.metadata.docs.rs]
 features = ["serde"]
 rustdoc-args = ["--cfg", "docsrs"]
 
 [dependencies]
 document-features = "0.2.7"
-ed448-goldilocks = { version = "0.9.0" }
+ed448-goldilocks-plus = { version = "0.13.1", features = ["alloc"], default-features = false }
 frost-core = { path = "../frost-core", version = "2.0.0", default-features = false }
 frost-rerandomized = { path = "../frost-rerandomized", version = "2.0.0", default-features = false }
 rand_core = "0.6"
@@ -42,11 +43,7 @@ rand_chacha = "0.3"
 serde_json = "1.0"
 
 [features]
-nightly = []
-default = ["serialization", "cheater-detection", "std"]
-#! ## Features
-## Enable standard library support.
-std = ["frost-core/std"]
+default = ["serialization", "cheater-detection"]
 ## Enable `serde` support for types that need to be communicated. You
 ## can use `serde` to serialize structs with any encoder that supports
 ## `serde` (e.g. JSON with `serde_json`).

frost-ed448/src/lib.rs

@@ -1,3 +1,4 @@
+#![no_std]
 #![allow(non_snake_case)]
 #![deny(missing_docs)]
 #![cfg_attr(docsrs, feature(doc_auto_cfg))]
@@ -7,11 +8,10 @@
 
 extern crate alloc;
 
-use std::collections::BTreeMap;
+use alloc::collections::BTreeMap;
 
-use ed448_goldilocks::{
-    curve::{edwards::CompressedEdwardsY, ExtendedPoint},
-    Scalar,
+use ed448_goldilocks_plus::{
+    CompressedEdwardsY, EdwardsPoint, Scalar, ScalarBytes, WideScalarBytes,
 };
 use frost_rerandomized::RandomizedCiphersuite;
 use rand_core::{CryptoRng, RngCore};
@@ -44,11 +44,11 @@ impl Field for Ed448ScalarField {
     type Serialization = [u8; 57];
 
     fn zero() -> Self::Scalar {
-        Scalar::zero()
+        Scalar::ZERO
     }
 
     fn one() -> Self::Scalar {
-        Scalar::one()
+        Scalar::ONE
     }
 
     fn invert(scalar: &Self::Scalar) -> Result<Self::Scalar, FieldError> {
@@ -64,11 +64,11 @@ impl Field for Ed448ScalarField {
     }
 
     fn serialize(scalar: &Self::Scalar) -> Self::Serialization {
-        scalar.to_bytes_rfc_8032()
+        scalar.to_bytes_rfc_8032().into()
     }
 
     fn deserialize(buf: &Self::Serialization) -> Result<Self::Scalar, FieldError> {
-        match Scalar::from_canonical_bytes(*buf) {
+        match Scalar::from_canonical_bytes(ScalarBytes::from_slice(buf)).into() {
             Some(s) => Ok(s),
             None => Err(FieldError::MalformedScalar),
         }
@@ -86,20 +86,20 @@ pub struct Ed448Group;
 impl Group for Ed448Group {
     type Field = Ed448ScalarField;
 
-    type Element = ExtendedPoint;
+    type Element = EdwardsPoint;
 
     type Serialization = [u8; 57];
 
     fn cofactor() -> <Self::Field as Field>::Scalar {
-        Scalar::one()
+        Scalar::ONE
     }
 
     fn identity() -> Self::Element {
-        Self::Element::identity()
+        Self::Element::IDENTITY
     }
 
     fn generator() -> Self::Element {
-        Self::Element::generator()
+        Self::Element::GENERATOR
     }
 
     fn serialize(element: &Self::Element) -> Result<Self::Serialization, GroupError> {
@@ -111,11 +111,11 @@ impl Group for Ed448Group {
 
     fn deserialize(buf: &Self::Serialization) -> Result<Self::Element, GroupError> {
         let compressed = CompressedEdwardsY(*buf);
-        match compressed.decompress() {
+        match compressed.decompress_unchecked().into_option() {
             Some(point) => {
                 if point == Self::identity() {
                     Err(GroupError::InvalidIdentityElement)
-                } else if point.is_torsion_free() {
+                } else if point.is_torsion_free().into() {
                     // decompress() does not check for canonicality, so we
                     // check by recompressing and comparing
                     if point.compress().0 != compressed.0 {
@@ -144,8 +144,9 @@ fn hash_to_array(inputs: &[&[u8]]) -> [u8; 114] {
 }
 
 fn hash_to_scalar(inputs: &[&[u8]]) -> Scalar {
-    let output = hash_to_array(inputs);
-    Scalar::from_bytes_mod_order_wide(&output)
+    let temp = hash_to_array(inputs);
+    let output = WideScalarBytes::from_slice(&temp);
+    Scalar::from_bytes_mod_order_wide(output)
 }
 
 /// Context string from the ciphersuite in the [spec]
@@ -230,7 +231,6 @@ pub type Identifier = frost::Identifier<E>;
 /// FROST(Ed448, SHAKE256) keys, key generation, key shares.
 pub mod keys {
     use super::*;
-    use std::collections::BTreeMap;
 
     /// The identifier list to use when generating key shares.
     pub type IdentifierList<'a> = frost::keys::IdentifierList<'a, E>;

frost-ed448/src/tests/deserialize.rs

@@ -1,10 +1,10 @@
 use crate::*;
-use ed448_goldilocks::curve::ExtendedPoint;
+use ed448_goldilocks_plus::EdwardsPoint;
 use frost_core::Ciphersuite;
 
 #[test]
 fn check_deserialize_non_canonical() {
-    let mut encoded_generator = ExtendedPoint::generator().compress().0;
+    let mut encoded_generator = EdwardsPoint::GENERATOR.compress().0;
 
     let r = <Ed448Shake256 as Ciphersuite>::Group::deserialize(&encoded_generator);
     assert!(r.is_ok());
@@ -35,7 +35,7 @@ fn check_deserialize_non_prime_order() {
 
 #[test]
 fn check_deserialize_identity() {
-    let encoded_identity = ExtendedPoint::identity().compress().0;
+    let encoded_identity = EdwardsPoint::IDENTITY.compress().0;
 
     let r = <Ed448Shake256 as Ciphersuite>::Group::deserialize(&encoded_identity);
     assert_eq!(r, Err(GroupError::InvalidIdentityElement));

frost-p256/Cargo.toml

@@ -17,6 +17,7 @@ repository = "https://github.com/ZcashFoundation/frost"
 categories = ["cryptography"]
 keywords = ["cryptography", "crypto", "threshold", "signature"]
 description = "A Schnorr signature scheme over the NIST P-256 curve that supports FROST."
+rust-version = "1.81"
 
 [package.metadata.docs.rs]
 features = ["serde"]
@@ -43,11 +44,7 @@ rand_chacha = "0.3"
 serde_json = "1.0"
 
 [features]
-nightly = []
-default = ["serialization", "cheater-detection", "std"]
-#! ## Features
-## Enable standard library support.
-std = ["frost-core/std"]
+default = ["serialization", "cheater-detection"]
 ## Enable `serde` support for types that need to be communicated. You
 ## can use `serde` to serialize structs with any encoder that supports
 ## `serde` (e.g. JSON with `serde_json`).

frost-p256/src/lib.rs

@@ -1,4 +1,4 @@
-#![cfg_attr(not(feature = "std"), no_std)]
+#![no_std]
 #![allow(non_snake_case)]
 #![deny(missing_docs)]
 #![cfg_attr(docsrs, feature(doc_auto_cfg))]

frost-rerandomized/Cargo.toml

@@ -17,6 +17,7 @@ repository = "https://github.com/ZcashFoundation/frost"
 categories = ["cryptography"]
 keywords = ["cryptography", "threshold", "signature", "schnorr", "randomized"]
 description = "Types and traits to support implementing a re-randomized variant of Flexible Round-Optimized Schnorr Threshold signature schemes (FROST)."
+rust-version = "1.81"
 
 [package.metadata.docs.rs]
 features = ["serde"]
@@ -34,11 +35,7 @@ rand_core = "0.6"
 [dev-dependencies]
 
 [features]
-nightly = []
 default = ["serialization", "cheater-detection"]
-#! ## Features
-## Enable standard library support.
-std = ["frost-core/std"]
 ## Enable `serde` support for types that need to be communicated. You
 ## can use `serde` to serialize structs with any encoder that supports
 ## `serde` (e.g. JSON with `serde_json`).

frost-rerandomized/src/lib.rs

@@ -9,7 +9,7 @@
 //! - Each participant should call [`sign`] and send the resulting
 //!   [`frost::round2::SignatureShare`] back to the Coordinator;
 //! - The Coordinator should then call [`aggregate`].
-#![cfg_attr(not(feature = "std"), no_std)]
+#![no_std]
 #![allow(non_snake_case)]
 
 extern crate alloc;

frost-ristretto255/Cargo.toml

@@ -13,6 +13,7 @@ repository = "https://github.com/ZcashFoundation/frost"
 categories = ["cryptography"]
 keywords = ["cryptography", "crypto", "ristretto", "threshold", "signature"]
 description = "A Schnorr signature scheme over the prime-order Ristretto group that supports FROST."
+rust-version = "1.81"
 
 [package.metadata.docs.rs]
 features = ["serde"]
@@ -40,11 +41,7 @@ rand_chacha = "0.3"
 serde_json = "1.0"
 
 [features]
-nightly = []
-default = ["serialization", "cheater-detection", "std"]
-#! ## Features
-## Enable standard library support.
-std = ["frost-core/std"]
+default = ["serialization", "cheater-detection"]
 ## Enable `serde` support for types that need to be communicated. You
 ## can use `serde` to serialize structs with any encoder that supports
 ## `serde` (e.g. JSON with `serde_json`).