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
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
use crate::{difficulty::bitcoin_retarget, error::ConsensusError, DeserializedLedger};
use snarkos_profiler::{end_timer, start_timer};
use snarkos_storage::SerialBlockHeader;
use snarkvm_algorithms::SNARK;
use snarkvm_curves::bls12_377::Bls12_377;
use snarkvm_dpc::{
testnet1::instantiated::{Components, Testnet1DPC},
DPCComponents,
DPCScheme,
MerkleRootHash,
Network,
PedersenMerkleRootHash,
ProgramScheme,
};
use snarkvm_posw::{Marlin, PoswMarlin};
use snarkvm_utilities::FromBytes;
use chrono::Utc;
use rand::{CryptoRng, Rng};
pub const TWO_HOURS_UNIX: i64 = 7200;
#[derive(Clone, Debug)]
pub struct ConsensusParameters {
pub network_id: Network,
pub max_block_size: usize,
pub max_nonce: u32,
pub target_block_time: i64,
pub verifier: PoswMarlin,
pub authorized_inner_snark_ids: Vec<Vec<u8>>,
}
impl ConsensusParameters {
pub fn get_block_difficulty(&self, prev_header: &SerialBlockHeader, block_timestamp: i64) -> u64 {
bitcoin_retarget(
block_timestamp,
prev_header.time,
self.target_block_time,
prev_header.difficulty_target,
)
}
pub fn verify_header(
&self,
header: &SerialBlockHeader,
parent_header: &SerialBlockHeader,
merkle_root_hash: &MerkleRootHash,
pedersen_merkle_root_hash: &PedersenMerkleRootHash,
) -> Result<(), ConsensusError> {
let hash_result = header.to_difficulty_hash();
let now = Utc::now().timestamp();
let future_timelimit: i64 = now + TWO_HOURS_UNIX;
let expected_difficulty = self.get_block_difficulty(parent_header, header.time);
let parent_hash = parent_header.hash();
if parent_hash != header.previous_block_hash {
return Err(ConsensusError::NoParent(
parent_hash.to_string(),
header.previous_block_hash.to_string(),
));
} else if header.merkle_root_hash != *merkle_root_hash {
return Err(ConsensusError::MerkleRoot(header.merkle_root_hash.to_string()));
} else if header.pedersen_merkle_root_hash != *pedersen_merkle_root_hash {
return Err(ConsensusError::PedersenMerkleRoot(
header.pedersen_merkle_root_hash.to_string(),
));
} else if header.time > future_timelimit {
return Err(ConsensusError::FuturisticTimestamp(future_timelimit, header.time));
} else if header.time < parent_header.time {
return Err(ConsensusError::TimestampInvalid(header.time, parent_header.time));
} else if hash_result > header.difficulty_target {
return Err(ConsensusError::PowInvalid(header.difficulty_target, hash_result));
} else if header.nonce >= self.max_nonce {
return Err(ConsensusError::NonceInvalid(header.nonce, self.max_nonce));
} else if header.difficulty_target != expected_difficulty {
return Err(ConsensusError::DifficultyMismatch(
expected_difficulty,
header.difficulty_target,
));
}
let proof = <Marlin<Bls12_377> as SNARK>::Proof::read_le(&header.proof.0[..])?;
let verification_timer = start_timer!(|| "POSW verify");
self.verifier
.verify(header.nonce, &proof, &header.pedersen_merkle_root_hash)?;
end_timer!(verification_timer);
Ok(())
}
#[allow(clippy::type_complexity)]
pub fn generate_program_proofs<'a, R: Rng + CryptoRng>(
dpc: &Testnet1DPC,
transaction_kernel: &<Testnet1DPC as DPCScheme<DeserializedLedger<'a, Components>>>::TransactionKernel,
rng: &mut R,
) -> Result<Vec<<Testnet1DPC as DPCScheme<DeserializedLedger<'a, Components>>>::Execution>, ConsensusError> {
let local_data = transaction_kernel.into_local_data();
let mut program_proofs = Vec::with_capacity(Components::NUM_TOTAL_RECORDS);
for position in 0..Components::NUM_TOTAL_RECORDS {
program_proofs.push(dpc.noop_program.execute(&local_data, position as u8, rng)?);
}
Ok(program_proofs)
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::get_block_reward;
use rand::{thread_rng, Rng};
use snarkos_testing::sync::DATA;
use snarkvm_dpc::PedersenMerkleRootHash;
#[test]
fn test_block_rewards() {
let rng = &mut thread_rng();
let first_halfing: u32 = 4 * 365 * 24 * 100;
let second_halfing: u32 = first_halfing * 2;
let mut block_reward: i64 = 150 * 1_000_000;
assert_eq!(get_block_reward(0).0, block_reward);
for _ in 0..100 {
let block_num: u32 = rng.gen_range(0..first_halfing);
assert_eq!(get_block_reward(block_num).0, block_reward);
}
block_reward /= 2;
assert_eq!(get_block_reward(first_halfing).0, block_reward);
for _ in 0..100 {
let block_num: u32 = rng.gen_range((first_halfing + 1)..second_halfing);
assert_eq!(get_block_reward(block_num).0, block_reward);
}
block_reward /= 2;
assert_eq!(get_block_reward(second_halfing).0, block_reward);
assert_eq!(get_block_reward(u32::MAX).0, block_reward);
for _ in 0..100 {
let block_num: u32 = rng.gen_range(second_halfing..u32::MAX);
assert_eq!(get_block_reward(block_num).0, block_reward);
}
}
#[test]
fn verify_header() {
let posw = PoswMarlin::load().unwrap();
let consensus: ConsensusParameters = ConsensusParameters {
max_block_size: 1_000_000usize,
max_nonce: std::u32::MAX - 1,
target_block_time: 2i64,
network_id: Network::Mainnet,
verifier: posw,
authorized_inner_snark_ids: vec![],
};
let b1 = DATA.block_1.clone();
let h1 = b1.header;
let b2 = DATA.block_2.clone();
let h2 = b2.header;
let merkle_root_hash = h2.merkle_root_hash.clone();
let pedersen_merkle_root = h2.pedersen_merkle_root_hash.clone();
consensus
.verify_header(&h2, &h1, &merkle_root_hash, &pedersen_merkle_root)
.unwrap();
let mut h2_err = h2.clone();
h2_err.previous_block_hash = [9u8; 32].into();
consensus
.verify_header(&h2_err, &h1, &merkle_root_hash, &pedersen_merkle_root)
.unwrap_err();
let mut h2_err = h2.clone();
h2_err.merkle_root_hash = MerkleRootHash([3; 32]);
consensus
.verify_header(&h2_err, &h1, &merkle_root_hash, &pedersen_merkle_root)
.unwrap_err();
let mut h2_err = h2.clone();
h2_err.time = 100;
consensus
.verify_header(&h2_err, &h1, &merkle_root_hash, &pedersen_merkle_root)
.unwrap_err();
let mut h2_err = h2.clone();
h2_err.time = Utc::now().timestamp() + 7201;
consensus
.verify_header(&h2_err, &h1, &merkle_root_hash, &pedersen_merkle_root)
.unwrap_err();
let mut h2_err = h2.clone();
h2_err.difficulty_target = 100;
consensus
.verify_header(&h2_err, &h1, &merkle_root_hash, &pedersen_merkle_root)
.unwrap_err();
let mut h2_err = h2.clone();
h2_err.nonce = std::u32::MAX;
consensus
.verify_header(&h2_err, &h1, &merkle_root_hash, &pedersen_merkle_root)
.unwrap_err();
let mut h2_err = h2.clone();
h2_err.pedersen_merkle_root_hash = PedersenMerkleRootHash([9; 32]);
consensus
.verify_header(&h2_err, &h1, &merkle_root_hash, &pedersen_merkle_root)
.unwrap_err();
let mut h2_err = h2;
h2_err.difficulty_target = consensus.get_block_difficulty(&h1, Utc::now().timestamp()) + 1;
consensus
.verify_header(&h2_err, &h1, &merkle_root_hash, &pedersen_merkle_root)
.unwrap_err();
}
}