diff --git a/Cargo.lock b/Cargo.lock index 23ee1e83..90c84ed7 100644 --- a/Cargo.lock +++ b/Cargo.lock @@ -463,6 +463,14 @@ dependencies = [ "zmij", ] +[[package]] +name = "sponge-cursor" +version = "0.1.0" +dependencies = [ + "hex-literal 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)", + "zeroize 1.8.2", +] + [[package]] name = "subtle" version = "2.6.1" diff --git a/Cargo.toml b/Cargo.toml index 85716c18..a674e416 100644 --- a/Cargo.toml +++ b/Cargo.toml @@ -11,6 +11,7 @@ members = [ "dbl", "hex-literal", "inout", + "sponge-cursor", "wycheproof2blb", "zeroize", "zeroize_derive", diff --git a/sponge-cursor/CHANGELOG.md b/sponge-cursor/CHANGELOG.md new file mode 100644 index 00000000..a5d6ec41 --- /dev/null +++ b/sponge-cursor/CHANGELOG.md @@ -0,0 +1,10 @@ +# Changelog +All notable changes to this project will be documented in this file. + +The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/), +and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html). + +## 0.1.0 (UNRELEASED) +- Initial release ([#1477]) + +[#1477]: https://github.com/RustCrypto/utils/pull/1477 diff --git a/sponge-cursor/Cargo.toml b/sponge-cursor/Cargo.toml new file mode 100644 index 00000000..a2118244 --- /dev/null +++ b/sponge-cursor/Cargo.toml @@ -0,0 +1,22 @@ +[package] +name = "sponge-cursor" +version = "0.1.0" +authors = ["RustCrypto Developers"] +edition = "2024" +rust-version = "1.85" +documentation = "https://docs.rs/sponge-cursor" +readme = "README.md" +repository = "https://github.com/RustCrypto/utils" +license = "MIT OR Apache-2.0" +keywords = ["block", "buffer"] +categories = ["cryptography", "no-std"] +description = "Cursor for sponge-based absorption and squeezing" + +[dependencies] +zeroize = { version = "1.4", optional = true, default-features = false } + +[dev-dependencies] +hex-literal = "1" + +[lints] +workspace = true diff --git a/sponge-cursor/LICENSE-APACHE b/sponge-cursor/LICENSE-APACHE new file mode 100644 index 00000000..78173fa2 --- /dev/null +++ b/sponge-cursor/LICENSE-APACHE @@ -0,0 +1,201 @@ + Apache License + Version 2.0, January 2004 + http://www.apache.org/licenses/ + +TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION + +1. 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IN NO EVENT +SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY +CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION +OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR +IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER +DEALINGS IN THE SOFTWARE. diff --git a/sponge-cursor/README.md b/sponge-cursor/README.md new file mode 100644 index 00000000..a9e52d9a --- /dev/null +++ b/sponge-cursor/README.md @@ -0,0 +1,40 @@ +# [RustCrypto]: Sponge Cursor + +[![crate][crate-image]][crate-link] +[![Docs][docs-image]][docs-link] +[![Build Status][build-image]][build-link] +![Apache2/MIT licensed][license-image] +![Rust Version][rustc-image] +[![Project Chat][chat-image]][chat-link] + +Cursor for sponge-based absorption and squeezing. + +## License + +Licensed under either of: + + * [Apache License, Version 2.0](http://www.apache.org/licenses/LICENSE-2.0) + * [MIT license](http://opensource.org/licenses/MIT) + +at your option. + +### Contribution + +Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions. + +[//]: # (badges) + +[crate-image]: https://img.shields.io/crates/v/sponge-cursor.svg +[crate-link]: https://crates.io/crates/sponge-cursor +[docs-image]: https://docs.rs/sponge-cursor/badge.svg +[docs-link]: https://docs.rs/sponge-cursor/ +[license-image]: https://img.shields.io/badge/license-Apache2.0/MIT-blue.svg +[rustc-image]: https://img.shields.io/badge/rustc-1.85+-blue.svg +[chat-image]: https://img.shields.io/badge/zulip-join_chat-blue.svg +[chat-link]: https://rustcrypto.zulipchat.com/#narrow/stream/260052-utils +[build-image]: https://github.com/RustCrypto/utils/actions/workflows/sponge-cursor.yml/badge.svg?branch=master +[build-link]: https://github.com/RustCrypto/utils/actions/workflows/sponge-cursor.yml?query=branch:master + +[//]: # (general links) + +[RustCrypto]: https://github.com/RustCrypto diff --git a/sponge-cursor/src/lib.rs b/sponge-cursor/src/lib.rs new file mode 100644 index 00000000..3113d1d0 --- /dev/null +++ b/sponge-cursor/src/lib.rs @@ -0,0 +1,234 @@ +#![no_std] +#![doc = include_str!("../README.md")] +#![doc( + html_logo_url = "https://raw.githubusercontent.com/RustCrypto/media/6ee8e381/logo.svg", + html_favicon_url = "https://raw.githubusercontent.com/RustCrypto/media/6ee8e381/logo.svg" +)] + +mod u64_le_utils; + +/// Cursor for implementing sponge-based absorption and squeezing. +/// +/// This type wraps `u8` and enforces that its value is always smaller than `RATE`. +/// +/// `RATE` MUST be smaller than `256`, trying to initialize cursor with an invalid rate will +/// result in a compilation error. +#[derive(Debug, Clone)] +pub struct SpongeCursor { + pos: u8, +} + +impl Default for SpongeCursor { + fn default() -> Self { + const { + assert!(RATE != 0); + assert!(RATE < u8::MAX as usize); + } + + Self { pos: 0 } + } +} + +// Note that the methods should compile into a panic-free code, +// see: https://rust.godbolt.org/z/r93WE8zq3 +impl SpongeCursor { + /// Create new cursor with the provided position. + /// + /// Returns `None` if `pos` is bigger or equal to `RATE`. + #[must_use] + pub fn new(pos: u8) -> Option { + if usize::from(pos) < RATE { + Some(Self { pos }) + } else { + None + } + } + + /// Get current cursor position as `u8`. + #[must_use] + #[inline(always)] + #[allow(clippy::missing_panics_doc, reason = "the method is panic-free")] + pub fn raw_pos(&self) -> u8 { + let rate_u8 = u8::try_from(RATE).expect("RATE is smaller than 256"); + debug_assert!(self.pos < rate_u8); + if self.pos < rate_u8 { + self.pos + } else { + // SAFETY: the type enforces that `pos` is always smaller than `RATE` + unsafe { core::hint::unreachable_unchecked() }; + } + } + + /// Get current cursor position as `usize`. + #[must_use] + #[inline(always)] + pub fn pos(&self) -> usize { + let pos = usize::from(self.pos); + debug_assert!(pos < RATE); + if pos < RATE { + pos + } else { + // SAFETY: the type enforces that `pos` is always smaller than `RATE` + unsafe { core::hint::unreachable_unchecked() }; + } + } + + /// Set new cursor position. + /// + /// # Panics + /// If `new_pos` is greater or equal to `RATE`. + fn set_pos(&mut self, new_pos: usize) { + assert!(new_pos < RATE); + self.pos = u8::try_from(new_pos).expect("`new_pos` is smaller than `RATE`"); + } + + /// Absorb bytes from `data` into `state` using little-endian byte order. + /// + /// Size of `state` in bytes MUST be greater or equal to `RATE`. + /// Using an invalid `N` will result in a compilation error. + #[allow(clippy::missing_panics_doc, reason = "the method is panic-free")] + #[inline] + pub fn absorb_u64_le( + &mut self, + state: &mut [u64; N], + sponge: fn(&mut [u64; N]), + mut data: &[u8], + ) { + const { + assert!(RATE <= size_of::<[u64; N]>()); + assert!(RATE < u8::MAX as usize); + assert!(RATE % size_of::() == 0); + }; + + if self.pos != 0 { + let pos = self.pos(); + let rem_len = RATE + .checked_sub(pos) + .expect("`pos` is always smaller than `RATE`"); + + if data.len() < rem_len { + u64_le_utils::absorb_partial::(state, pos, data); + self.set_pos(pos + data.len()); + return; + } + + let (head, tail) = data.split_at(rem_len); + data = tail; + u64_le_utils::absorb_partial::(state, pos, head); + + sponge(state); + } + + let blocks = data.chunks_exact(RATE); + let tail = blocks.remainder(); + + for block in blocks { + let block: &[u8; RATE] = block.try_into().expect("`block` has correct size"); + u64_le_utils::absorb_full(state, block); + sponge(state); + } + + if !tail.is_empty() { + u64_le_utils::absorb_partial::(state, 0, tail); + } + + self.set_pos(tail.len()); + } + + /// Squeeze data from `state` by reading it into `buf` using little-endian byte order. + /// + /// Size of `state` in bytes MUST be greater or equal to `RATE`. + /// Using an invalid `N` will result in a compilation error. + #[inline] + pub fn squeeze_read_u64_le( + &mut self, + state: &mut [u64; N], + sponge: fn(&mut [u64; N]), + buf: &mut [u8], + ) { + self.squeeze_inner_u64_le( + state, + sponge, + buf, + u64_le_utils::squeeze_read_partial::, + u64_le_utils::squeeze_read_full, + ); + } + + /// Squeeze data from `state` by XOR-ing it with data in `buf` using little-endian byte order. + /// + /// Size of `state` in bytes MUST be greater or equal to `RATE`. + /// Using an invalid `N` will result in a compilation error. + #[inline] + pub fn squeeze_xor_u64_le( + &mut self, + state: &mut [u64; N], + sponge: fn(&mut [u64; N]), + buf: &mut [u8], + ) { + self.squeeze_inner_u64_le( + state, + sponge, + buf, + u64_le_utils::squeeze_xor_partial::, + u64_le_utils::squeeze_xor_full, + ); + } + + /// Squeeze data by calling custom functions using little-endian byte order. + #[inline(always)] + fn squeeze_inner_u64_le( + &mut self, + state: &mut [u64; N], + sponge: fn(&mut [u64; N]), + mut buf: &mut [u8], + process_partial: fn(&[u64; N], usize, &mut [u8]), + process_full: fn(&[u64; N], &mut [u8; RATE]), + ) { + const { + assert!(RATE <= size_of::<[u64; N]>()); + assert!(RATE < u8::MAX as usize); + assert!(RATE % size_of::() == 0); + }; + + if self.pos != 0 { + let pos = self.pos(); + let rem_len = RATE - pos; + + if buf.len() < rem_len { + process_partial(state, pos, buf); + self.set_pos(pos + buf.len()); + return; + } + + let (head, tail) = buf.split_at_mut(rem_len); + buf = tail; + + process_partial(state, pos, head); + } + + let mut blocks = buf.chunks_exact_mut(RATE); + + for block in &mut blocks { + sponge(state); + let block = block.try_into().expect("`block` has correct size"); + process_full(state, block); + } + + let tail = blocks.into_remainder(); + + if !tail.is_empty() { + sponge(state); + process_partial(state, 0, tail); + } + + self.set_pos(tail.len()); + } +} + +#[cfg(feature = "zeroize")] +impl zeroize::Zeroize for SpongeCursor { + fn zeroize(&mut self) { + self.pos.zeroize(); + } +} diff --git a/sponge-cursor/src/u64_le_utils.rs b/sponge-cursor/src/u64_le_utils.rs new file mode 100644 index 00000000..39b25639 --- /dev/null +++ b/sponge-cursor/src/u64_le_utils.rs @@ -0,0 +1,156 @@ +//! Utility functions. +//! +//! Note that support of big-endian targets is somewhat sub-optimal since we prioritized +//! simplicity of the implementation. + +#[inline(always)] +pub(crate) fn absorb_full( + state: &mut [u64; N], + block: &[u8; RATE], +) { + const { + assert!(size_of::<[u8; RATE]>() <= size_of::<[u64; N]>()); + assert!(RATE % size_of::() == 0); + }; + + let chunks = block.chunks_exact(size_of::()); + assert!(chunks.remainder().is_empty()); + + for (dst, chunk) in state.iter_mut().zip(chunks) { + let chunk = chunk.try_into().expect("chunk has correct length"); + *dst ^= u64::from_le_bytes(chunk); + } +} + +#[inline(always)] +pub(crate) fn absorb_partial( + state: &mut [u64; N], + offset: usize, + data: &[u8], +) { + const { + assert!(size_of::<[u8; RATE]>() <= size_of::<[u64; N]>()); + assert!(RATE % size_of::() == 0); + }; + + if cfg!(target_endian = "little") { + // SAFETY: casting of `&mut [u64; N]` into `&mut [u8; M]` is safe if + // `size_of::<[u8; M]>() <= size_of::<[u64; N]>())` + let sub_state: &mut [u8; RATE] = unsafe { &mut *(state.as_mut_ptr().cast()) }; + + let dst = &mut sub_state[offset..][..data.len()]; + + for i in 0..dst.len() { + dst[i] ^= data[i]; + } + } else { + let mut buf = [0u8; RATE]; + buf[offset..][..data.len()].copy_from_slice(data); + + let chunks = buf.chunks_exact(size_of::()); + assert!(chunks.remainder().is_empty()); + + for (dst, chunk) in state.iter_mut().zip(chunks) { + let chunk = chunk.try_into().expect("chunk has correct length"); + *dst ^= u64::from_le_bytes(chunk); + } + } +} + +#[inline(always)] +pub(crate) fn squeeze_read_full( + state: &[u64; N], + dst: &mut [u8; RATE], +) { + const { + assert!(size_of::<[u8; RATE]>() <= size_of::<[u64; N]>()); + assert!(RATE % size_of::() == 0); + }; + + let mut dst_chunks = dst.chunks_exact_mut(size_of::()); + for (src, dst_chunk) in state.iter().zip(&mut dst_chunks) { + dst_chunk.copy_from_slice(&src.to_le_bytes()); + } + assert!(dst_chunks.into_remainder().is_empty()); +} + +#[inline(always)] +pub(crate) fn squeeze_read_partial( + state: &[u64; N], + offset: usize, + dst: &mut [u8], +) { + const { + assert!(size_of::<[u8; RATE]>() <= size_of::<[u64; N]>()); + assert!(RATE % size_of::() == 0); + }; + + let mut buf = [0u8; RATE]; + + let sub_state: &[u8; RATE] = if cfg!(target_endian = "little") { + // SAFETY: casting of `&[u64; N]` into `&[u8; M]` is safe if + // `size_of::<[u8; M]>() <= size_of::<[u64; N]>())` + unsafe { &*(state.as_ptr().cast::<[u8; RATE]>()) } + } else { + let mut chunks = buf.chunks_exact_mut(size_of::()); + for (src, dst) in state.iter().zip(&mut chunks) { + dst.copy_from_slice(&src.to_le_bytes()); + } + assert!(chunks.into_remainder().is_empty()); + &buf + }; + + let src = &sub_state[offset..][..dst.len()]; + dst.copy_from_slice(src); +} + +#[inline(always)] +pub(crate) fn squeeze_xor_full( + state: &[u64; N], + dst: &mut [u8; RATE], +) { + const { + assert!(size_of::<[u8; RATE]>() <= size_of::<[u64; N]>()); + assert!(RATE % size_of::() == 0); + }; + + let mut dst_chunks = dst.chunks_exact_mut(size_of::()); + for (src, dst_chunk) in state.iter().zip(&mut dst_chunks) { + let dst_chunk: &mut [u8; 8] = dst_chunk.try_into().expect("chunk has correct size"); + let chunk_val = u64::from_le_bytes(*dst_chunk); + *dst_chunk = (chunk_val ^ src).to_le_bytes(); + } + assert!(dst_chunks.into_remainder().is_empty()); +} + +#[inline(always)] +pub(crate) fn squeeze_xor_partial( + state: &[u64; N], + offset: usize, + dst: &mut [u8], +) { + const { + assert!(size_of::<[u8; RATE]>() <= size_of::<[u64; N]>()); + assert!(RATE % size_of::() == 0); + }; + + let mut buf = [0u8; RATE]; + + let sub_state: &[u8; RATE] = if cfg!(target_endian = "little") { + // SAFETY: casting of `&[u64; N]` into `&[u8; M]` is safe if + // `size_of::<[u8; M]>() <= size_of::<[u64; N]>())` + unsafe { &*(state.as_ptr().cast::<[u8; RATE]>()) } + } else { + let mut chunks = buf.chunks_exact_mut(size_of::()); + for (src, dst) in state.iter().zip(&mut chunks) { + dst.copy_from_slice(&src.to_le_bytes()); + } + assert!(chunks.into_remainder().is_empty()); + &buf + }; + + let src = &sub_state[offset..][..dst.len()]; + for i in 0..dst.len() { + dst[i] ^= src[i]; + } +} diff --git a/sponge-cursor/tests/mod.rs b/sponge-cursor/tests/mod.rs new file mode 100644 index 00000000..75e75a67 --- /dev/null +++ b/sponge-cursor/tests/mod.rs @@ -0,0 +1 @@ +//! Basic tests