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| 1 | +use ascon::State; |
| 2 | +pub use digest::{self, Digest, ExtendableOutput, Reset, Update, XofReader}; |
| 3 | +use digest::{ |
| 4 | + HashMarker, Output, OutputSizeUser, |
| 5 | + block_api::{ |
| 6 | + AlgorithmName, Block, BlockSizeUser, Buffer, BufferKindUser, Eager, FixedOutputCore, |
| 7 | + UpdateCore, |
| 8 | + }, |
| 9 | + common::hazmat::{DeserializeStateError, SerializableState, SerializedState}, |
| 10 | + consts::{U8, U32, U40}, |
| 11 | +}; |
| 12 | + |
| 13 | +/// Initial state of Ascon-Hash256 |
| 14 | +const IV: State = [ |
| 15 | + 0x9b1e_5494_e934_d681, |
| 16 | + 0x4bc3_a01e_3337_51d2, |
| 17 | + 0xae65_396c_6b34_b81a, |
| 18 | + 0x3c7f_d4a4_d56a_4db3, |
| 19 | + 0x1a5c_4649_06c5_976d, |
| 20 | +]; |
| 21 | + |
| 22 | +/// Ascon-Hash256 block-level hasher |
| 23 | +#[derive(Clone, Debug)] |
| 24 | +pub struct AsconHash256Core { |
| 25 | + state: State, |
| 26 | +} |
| 27 | + |
| 28 | +impl Default for AsconHash256Core { |
| 29 | + #[inline] |
| 30 | + fn default() -> Self { |
| 31 | + Self { state: IV } |
| 32 | + } |
| 33 | +} |
| 34 | + |
| 35 | +impl HashMarker for AsconHash256Core {} |
| 36 | + |
| 37 | +impl BlockSizeUser for AsconHash256Core { |
| 38 | + type BlockSize = U8; |
| 39 | +} |
| 40 | + |
| 41 | +impl BufferKindUser for AsconHash256Core { |
| 42 | + type BufferKind = Eager; |
| 43 | +} |
| 44 | + |
| 45 | +impl OutputSizeUser for AsconHash256Core { |
| 46 | + type OutputSize = U32; |
| 47 | +} |
| 48 | + |
| 49 | +impl UpdateCore for AsconHash256Core { |
| 50 | + #[inline] |
| 51 | + fn update_blocks(&mut self, blocks: &[Block<Self>]) { |
| 52 | + for block in blocks { |
| 53 | + self.state[0] ^= u64::from_le_bytes(block.0); |
| 54 | + ascon::permute12(&mut self.state); |
| 55 | + } |
| 56 | + } |
| 57 | +} |
| 58 | + |
| 59 | +impl FixedOutputCore for AsconHash256Core { |
| 60 | + #[inline] |
| 61 | + fn finalize_fixed_core(&mut self, buffer: &mut Buffer<Self>, out: &mut Output<Self>) { |
| 62 | + let len = buffer.get_pos(); |
| 63 | + let last_block = buffer.pad_with_zeros(); |
| 64 | + let pad = 1u64 << (8 * len); |
| 65 | + self.state[0] ^= u64::from_le_bytes(last_block.0) ^ pad; |
| 66 | + |
| 67 | + ascon::permute12(&mut self.state); |
| 68 | + |
| 69 | + let mut chunks = out.chunks_exact_mut(size_of::<u64>()); |
| 70 | + for chunk in &mut chunks { |
| 71 | + chunk.copy_from_slice(&self.state[0].to_le_bytes()); |
| 72 | + ascon::permute12(&mut self.state); |
| 73 | + } |
| 74 | + assert!(chunks.into_remainder().is_empty()); |
| 75 | + } |
| 76 | +} |
| 77 | + |
| 78 | +impl Reset for AsconHash256Core { |
| 79 | + #[inline] |
| 80 | + fn reset(&mut self) { |
| 81 | + self.state = IV; |
| 82 | + } |
| 83 | +} |
| 84 | + |
| 85 | +impl AlgorithmName for AsconHash256Core { |
| 86 | + #[inline] |
| 87 | + fn write_alg_name(f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result { |
| 88 | + f.write_str("Ascon-Hash256") |
| 89 | + } |
| 90 | +} |
| 91 | + |
| 92 | +impl SerializableState for AsconHash256Core { |
| 93 | + type SerializedStateSize = U40; |
| 94 | + |
| 95 | + #[inline] |
| 96 | + fn serialize(&self) -> SerializedState<Self> { |
| 97 | + let mut res = SerializedState::<Self>::default(); |
| 98 | + let mut chunks = res.chunks_exact_mut(size_of::<u64>()); |
| 99 | + for (src, dst) in self.state.iter().zip(&mut chunks) { |
| 100 | + dst.copy_from_slice(&src.to_le_bytes()); |
| 101 | + } |
| 102 | + assert!(chunks.into_remainder().is_empty()); |
| 103 | + res |
| 104 | + } |
| 105 | + |
| 106 | + #[inline] |
| 107 | + fn deserialize( |
| 108 | + serialized_state: &SerializedState<Self>, |
| 109 | + ) -> Result<Self, DeserializeStateError> { |
| 110 | + let state = core::array::from_fn(|i| { |
| 111 | + let n = size_of::<u64>(); |
| 112 | + let chunk = &serialized_state[n * i..][..n]; |
| 113 | + u64::from_le_bytes(chunk.try_into().expect("chunk has correct length")) |
| 114 | + }); |
| 115 | + Ok(Self { state }) |
| 116 | + } |
| 117 | +} |
| 118 | + |
| 119 | +impl Drop for AsconHash256Core { |
| 120 | + #[inline] |
| 121 | + fn drop(&mut self) { |
| 122 | + #[cfg(feature = "zeroize")] |
| 123 | + { |
| 124 | + use digest::zeroize::Zeroize; |
| 125 | + self.state.zeroize() |
| 126 | + } |
| 127 | + } |
| 128 | +} |
| 129 | + |
| 130 | +#[cfg(feature = "zeroize")] |
| 131 | +impl digest::zeroize::ZeroizeOnDrop for AsconHash256Core {} |
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