1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
use super::{BuiltinEval, CallResult, PrecompileContext, PrecompileOk, Result};
use evm_state::{TransactionSignature, H160, H256};
use std::collections::HashMap;
use std::str::FromStr;
const WORD_LEN: usize = 32;
#[derive(Debug)]
pub struct Identity;
#[derive(Debug)]
pub struct Sha256;
#[derive(Debug)]
pub struct Ripemd160;
#[derive(Debug)]
pub struct EcRecover;
#[derive(Debug)]
pub struct Modexp;
#[derive(Debug)]
pub struct Bn128Add;
#[derive(Debug)]
pub struct Bn128Mul;
#[derive(Debug)]
pub struct Bn128Pairing;
#[derive(Debug)]
pub struct Blake2F;
trait Precompile {
fn address() -> H160;
fn pricer() -> Pricer;
fn implementation(source: &[u8], cx: PrecompileContext) -> Result<Vec<u8>>;
fn insert_to_map(map: &mut HashMap<H160, BuiltinEval>)
where
Self: Sized,
{
assert!(map
.insert(Self::address(), &|source, cx| execute_precompile::<Self>(
source, cx
))
.is_none());
}
}
impl Precompile for EcRecover {
fn address() -> H160 {
H160::from_str("0000000000000000000000000000000000000001")
.expect("Serialization of static data should be determenistic and never fail.")
}
fn pricer() -> Pricer {
Pricer::Linear { base: 60, word: 12 }
}
fn implementation(source: &[u8], _cx: PrecompileContext) -> Result<Vec<u8>> {
use evm_state::secp256k1::{Message, SECP256K1};
use evm_state::transactions::addr_from_public_key;
let len = std::cmp::min(source.len(), 128);
let mut input = [0; 128];
input[..len].copy_from_slice(&source[..len]);
let hash = &input[0..32];
let v = H256::from_slice(&input[32..64]);
let r = H256::from_slice(&input[64..96]);
let s = H256::from_slice(&input[96..128]);
if v.0[..31] != [0; 31] {
return Ok(vec![]);
}
let v = v[31];
let signature = TransactionSignature { v: v as u64, r, s };
if !signature.is_valid() {
return Ok(vec![]);
}
let signature = if let Ok(s) = signature.to_recoverable_signature() {
s
} else {
return Ok(vec![]);
};
let public_key =
if let Ok(p) = SECP256K1.recover(&Message::from_slice(hash).unwrap(), &signature) {
p
} else {
return Ok(vec![]);
};
let addr = addr_from_public_key(&public_key);
let mut result = vec![0; 32];
result[12..].copy_from_slice(addr.as_bytes());
Ok(result)
}
}
impl Precompile for Sha256 {
fn address() -> H160 {
H160::from_str("0000000000000000000000000000000000000002")
.expect("Serialization of static data should be determenistic and never fail.")
}
fn pricer() -> Pricer {
Pricer::Linear { base: 60, word: 12 }
}
fn implementation(source: &[u8], _cx: PrecompileContext) -> Result<Vec<u8>> {
use sha2::{Digest, Sha256};
let mut hasher = Sha256::new();
hasher.update(source);
let result = hasher.finalize();
Ok(result.to_vec())
}
}
impl Precompile for Ripemd160 {
fn address() -> H160 {
H160::from_str("0000000000000000000000000000000000000003")
.expect("Serialization of static data should be determenistic and never fail.")
}
fn pricer() -> Pricer {
Pricer::Linear { base: 60, word: 12 }
}
fn implementation(source: &[u8], _cx: PrecompileContext) -> Result<Vec<u8>> {
use ripemd160::{Digest, Ripemd160};
let mut hasher = Ripemd160::new();
hasher.update(source);
let array = hasher.finalize();
let mut result = vec![0; 32];
result[12..].copy_from_slice(array.as_slice());
Ok(result)
}
}
impl Precompile for Identity {
fn address() -> H160 {
H160::from_str("0000000000000000000000000000000000000004")
.expect("Serialization of static data should be determenistic and never fail.")
}
fn pricer() -> Pricer {
Pricer::Linear { base: 15, word: 3 }
}
fn implementation(source: &[u8], _cx: PrecompileContext) -> Result<Vec<u8>> {
Ok(source.to_vec())
}
}
enum Pricer {
Linear { base: u64, word: u64 },
}
impl Pricer {
fn calculate_price(&self, source: &[u8]) -> u64 {
match self {
Pricer::Linear { base, word } => {
let num_words = (source.len() / WORD_LEN) as u64;
base + word * num_words
}
}
}
}
pub fn extend_precompile_map(map: &mut HashMap<H160, BuiltinEval>) {
Identity::insert_to_map(map);
Sha256::insert_to_map(map);
Ripemd160::insert_to_map(map);
EcRecover::insert_to_map(map);
}
fn execute_precompile<T: Precompile>(source: &[u8], cx: PrecompileContext) -> CallResult {
let gas_used = T::pricer().calculate_price(source);
let bytes = T::implementation(source, cx)?;
Ok(PrecompileOk::new(
evm_state::ExitSucceed::Returned,
bytes,
gas_used,
))
}