topsoil_core/
hash.rs

1// This file is part of Soil.
2
3// Copyright (C) Soil contributors.
4// Copyright (C) Parity Technologies (UK) Ltd.
5// SPDX-License-Identifier: Apache-2.0 OR GPL-3.0-or-later WITH Classpath-exception-2.0
6
7//! Hash utilities.
8
9use alloc::vec::Vec;
10use codec::{Codec, MaxEncodedLen};
11use subsoil::io::hashing::{blake2_128, blake2_256, twox_128, twox_256, twox_64};
12use subsoil::metadata_ir;
13
14// This trait must be kept coherent with topsoil-support-procedural HasherKind usage
15pub trait Hashable: Sized {
16	fn blake2_128(&self) -> [u8; 16];
17	fn blake2_256(&self) -> [u8; 32];
18	fn blake2_128_concat(&self) -> Vec<u8>;
19	fn twox_128(&self) -> [u8; 16];
20	fn twox_256(&self) -> [u8; 32];
21	fn twox_64_concat(&self) -> Vec<u8>;
22	fn identity(&self) -> Vec<u8>;
23}
24
25impl<T: Codec> Hashable for T {
26	fn blake2_128(&self) -> [u8; 16] {
27		self.using_encoded(blake2_128)
28	}
29	fn blake2_256(&self) -> [u8; 32] {
30		self.using_encoded(blake2_256)
31	}
32	fn blake2_128_concat(&self) -> Vec<u8> {
33		self.using_encoded(Blake2_128Concat::hash)
34	}
35	fn twox_128(&self) -> [u8; 16] {
36		self.using_encoded(twox_128)
37	}
38	fn twox_256(&self) -> [u8; 32] {
39		self.using_encoded(twox_256)
40	}
41	fn twox_64_concat(&self) -> Vec<u8> {
42		self.using_encoded(Twox64Concat::hash)
43	}
44	fn identity(&self) -> Vec<u8> {
45		self.encode()
46	}
47}
48
49/// Hasher to use to hash keys to insert to storage.
50pub trait StorageHasher: 'static {
51	const METADATA: metadata_ir::StorageHasherIR;
52	type Output: AsRef<[u8]>;
53	fn hash(x: &[u8]) -> Self::Output;
54
55	/// The max length of the final hash, for the given key type.
56	fn max_len<K: MaxEncodedLen>() -> usize;
57}
58
59/// Hasher to use to hash keys to insert to storage.
60///
61/// Reversible hasher store the encoded key after the hash part.
62pub trait ReversibleStorageHasher: StorageHasher {
63	/// Split the hash part out of the input.
64	///
65	/// I.e. for input `&[hash ++ key ++ some]` returns `&[key ++ some]`
66	fn reverse(x: &[u8]) -> &[u8];
67}
68
69/// Store the key directly.
70pub struct Identity;
71impl StorageHasher for Identity {
72	const METADATA: metadata_ir::StorageHasherIR = metadata_ir::StorageHasherIR::Identity;
73	type Output = Vec<u8>;
74	fn hash(x: &[u8]) -> Vec<u8> {
75		x.to_vec()
76	}
77	fn max_len<K: MaxEncodedLen>() -> usize {
78		K::max_encoded_len()
79	}
80}
81impl ReversibleStorageHasher for Identity {
82	fn reverse(x: &[u8]) -> &[u8] {
83		x
84	}
85}
86
87/// Hash storage keys with `concat(twox64(key), key)`
88pub struct Twox64Concat;
89impl StorageHasher for Twox64Concat {
90	const METADATA: metadata_ir::StorageHasherIR = metadata_ir::StorageHasherIR::Twox64Concat;
91	type Output = Vec<u8>;
92	fn hash(x: &[u8]) -> Vec<u8> {
93		twox_64(x).iter().chain(x.iter()).cloned().collect::<Vec<_>>()
94	}
95	fn max_len<K: MaxEncodedLen>() -> usize {
96		K::max_encoded_len().saturating_add(8)
97	}
98}
99impl ReversibleStorageHasher for Twox64Concat {
100	fn reverse(x: &[u8]) -> &[u8] {
101		if x.len() < 8 {
102			log::error!("Invalid reverse: hash length too short");
103			return &[];
104		}
105		&x[8..]
106	}
107}
108
109/// Hash storage keys with `concat(blake2_128(key), key)`
110pub struct Blake2_128Concat;
111impl StorageHasher for Blake2_128Concat {
112	const METADATA: metadata_ir::StorageHasherIR = metadata_ir::StorageHasherIR::Blake2_128Concat;
113	type Output = Vec<u8>;
114	fn hash(x: &[u8]) -> Vec<u8> {
115		blake2_128(x).iter().chain(x.iter()).cloned().collect::<Vec<_>>()
116	}
117	fn max_len<K: MaxEncodedLen>() -> usize {
118		K::max_encoded_len().saturating_add(16)
119	}
120}
121impl ReversibleStorageHasher for Blake2_128Concat {
122	fn reverse(x: &[u8]) -> &[u8] {
123		if x.len() < 16 {
124			log::error!("Invalid reverse: hash length too short");
125			return &[];
126		}
127		&x[16..]
128	}
129}
130
131/// Hash storage keys with blake2 128
132pub struct Blake2_128;
133impl StorageHasher for Blake2_128 {
134	const METADATA: metadata_ir::StorageHasherIR = metadata_ir::StorageHasherIR::Blake2_128;
135	type Output = [u8; 16];
136	fn hash(x: &[u8]) -> [u8; 16] {
137		blake2_128(x)
138	}
139	fn max_len<K: MaxEncodedLen>() -> usize {
140		16
141	}
142}
143
144/// Hash storage keys with blake2 256
145pub struct Blake2_256;
146impl StorageHasher for Blake2_256 {
147	const METADATA: metadata_ir::StorageHasherIR = metadata_ir::StorageHasherIR::Blake2_256;
148	type Output = [u8; 32];
149	fn hash(x: &[u8]) -> [u8; 32] {
150		blake2_256(x)
151	}
152	fn max_len<K: MaxEncodedLen>() -> usize {
153		32
154	}
155}
156
157/// Hash storage keys with twox 128
158pub struct Twox128;
159impl StorageHasher for Twox128 {
160	const METADATA: metadata_ir::StorageHasherIR = metadata_ir::StorageHasherIR::Twox128;
161	type Output = [u8; 16];
162	fn hash(x: &[u8]) -> [u8; 16] {
163		twox_128(x)
164	}
165	fn max_len<K: MaxEncodedLen>() -> usize {
166		16
167	}
168}
169
170/// Hash storage keys with twox 256
171pub struct Twox256;
172impl StorageHasher for Twox256 {
173	const METADATA: metadata_ir::StorageHasherIR = metadata_ir::StorageHasherIR::Twox256;
174	type Output = [u8; 32];
175	fn hash(x: &[u8]) -> [u8; 32] {
176		twox_256(x)
177	}
178	fn max_len<K: MaxEncodedLen>() -> usize {
179		32
180	}
181}
182
183#[cfg(test)]
184mod tests {
185	use super::*;
186
187	#[test]
188	fn test_twox_64_concat() {
189		let r = Twox64Concat::hash(b"foo");
190		assert_eq!(r.split_at(8), (&twox_128(b"foo")[..8], &b"foo"[..]))
191	}
192
193	#[test]
194	fn test_blake2_128_concat() {
195		let r = Blake2_128Concat::hash(b"foo");
196		assert_eq!(r.split_at(16), (&blake2_128(b"foo")[..], &b"foo"[..]))
197	}
198
199	#[test]
200	fn max_lengths() {
201		use codec::Encode;
202		let encoded_0u32 = &0u32.encode()[..];
203		assert_eq!(Twox64Concat::hash(encoded_0u32).len(), Twox64Concat::max_len::<u32>());
204		assert_eq!(Twox128::hash(encoded_0u32).len(), Twox128::max_len::<u32>());
205		assert_eq!(Twox256::hash(encoded_0u32).len(), Twox256::max_len::<u32>());
206		assert_eq!(Blake2_128::hash(encoded_0u32).len(), Blake2_128::max_len::<u32>());
207		assert_eq!(Blake2_128Concat::hash(encoded_0u32).len(), Blake2_128Concat::max_len::<u32>());
208		assert_eq!(Blake2_256::hash(encoded_0u32).len(), Blake2_256::max_len::<u32>());
209		assert_eq!(Identity::hash(encoded_0u32).len(), Identity::max_len::<u32>());
210	}
211}
topsoil_core/hash.rs

topsoil_core/
hash.rs
