consensus_core/
block.rs

1// Copyright (c) Mysten Labs, Inc.
2// Modifications Copyright (c) 2024 IOTA Stiftung
3// SPDX-License-Identifier: Apache-2.0
4
5use std::{
6    fmt,
7    hash::{Hash, Hasher},
8    ops::Deref,
9    sync::Arc,
10};
11
12use bytes::Bytes;
13use consensus_config::{
14    AuthorityIndex, DIGEST_LENGTH, DefaultHashFunction, Epoch, ProtocolKeyPair,
15    ProtocolKeySignature, ProtocolPublicKey,
16};
17use enum_dispatch::enum_dispatch;
18use fastcrypto::hash::{Digest, HashFunction};
19use serde::{Deserialize, Serialize};
20use shared_crypto::intent::{Intent, IntentMessage, IntentScope};
21
22use crate::{
23    commit::CommitVote,
24    context::Context,
25    ensure,
26    error::{ConsensusError, ConsensusResult},
27};
28
29/// Round number of a block.
30pub type Round = u32;
31
32pub(crate) const GENESIS_ROUND: Round = 0;
33
34/// Block proposal as epoch UNIX timestamp in milliseconds.
35pub type BlockTimestampMs = u64;
36
37/// IOTA transaction in serialised bytes
38#[derive(Clone, Eq, PartialEq, Serialize, Deserialize, Default, Debug)]
39pub struct Transaction {
40    data: Bytes,
41}
42
43impl Transaction {
44    pub fn new(data: Vec<u8>) -> Self {
45        Self { data: data.into() }
46    }
47
48    pub fn data(&self) -> &[u8] {
49        &self.data
50    }
51
52    pub fn into_data(self) -> Bytes {
53        self.data
54    }
55}
56
57/// A block includes references to previous round blocks and transactions that
58/// the authority considers valid.
59/// Well behaved authorities produce at most one block per round, but malicious
60/// authorities can equivocate.
61#[derive(Clone, Deserialize, Serialize)]
62#[enum_dispatch(BlockAPI)]
63pub enum Block {
64    V1(BlockV1),
65}
66
67#[enum_dispatch]
68pub trait BlockAPI {
69    fn epoch(&self) -> Epoch;
70    fn round(&self) -> Round;
71    fn author(&self) -> AuthorityIndex;
72    fn slot(&self) -> Slot;
73    fn timestamp_ms(&self) -> BlockTimestampMs;
74    fn ancestors(&self) -> &[BlockRef];
75    fn transactions(&self) -> &[Transaction];
76    fn commit_votes(&self) -> &[CommitVote];
77    fn misbehavior_reports(&self) -> &[MisbehaviorReport];
78}
79
80#[derive(Clone, Default, Deserialize, Serialize)]
81pub struct BlockV1 {
82    epoch: Epoch,
83    round: Round,
84    author: AuthorityIndex,
85    // TODO: during verification ensure that timestamp_ms >= ancestors.timestamp
86    timestamp_ms: BlockTimestampMs,
87    ancestors: Vec<BlockRef>,
88    transactions: Vec<Transaction>,
89    commit_votes: Vec<CommitVote>,
90    misbehavior_reports: Vec<MisbehaviorReport>,
91}
92
93impl BlockV1 {
94    pub(crate) fn new(
95        epoch: Epoch,
96        round: Round,
97        author: AuthorityIndex,
98        timestamp_ms: BlockTimestampMs,
99        ancestors: Vec<BlockRef>,
100        transactions: Vec<Transaction>,
101        commit_votes: Vec<CommitVote>,
102        misbehavior_reports: Vec<MisbehaviorReport>,
103    ) -> BlockV1 {
104        Self {
105            epoch,
106            round,
107            author,
108            timestamp_ms,
109            ancestors,
110            transactions,
111            commit_votes,
112            misbehavior_reports,
113        }
114    }
115
116    fn genesis_block(epoch: Epoch, author: AuthorityIndex) -> Self {
117        Self {
118            epoch,
119            round: GENESIS_ROUND,
120            author,
121            timestamp_ms: 0,
122            ancestors: vec![],
123            transactions: vec![],
124            commit_votes: vec![],
125            misbehavior_reports: vec![],
126        }
127    }
128}
129
130impl BlockAPI for BlockV1 {
131    fn epoch(&self) -> Epoch {
132        self.epoch
133    }
134
135    fn round(&self) -> Round {
136        self.round
137    }
138
139    fn author(&self) -> AuthorityIndex {
140        self.author
141    }
142
143    fn slot(&self) -> Slot {
144        Slot::new(self.round, self.author)
145    }
146
147    fn timestamp_ms(&self) -> BlockTimestampMs {
148        self.timestamp_ms
149    }
150
151    fn ancestors(&self) -> &[BlockRef] {
152        &self.ancestors
153    }
154
155    fn transactions(&self) -> &[Transaction] {
156        &self.transactions
157    }
158
159    fn commit_votes(&self) -> &[CommitVote] {
160        &self.commit_votes
161    }
162
163    fn misbehavior_reports(&self) -> &[MisbehaviorReport] {
164        &self.misbehavior_reports
165    }
166}
167
168/// `BlockRef` uniquely identifies a `VerifiedBlock` via `digest`. It also
169/// contains the slot info (round and author) so it can be used in logic such as
170/// aggregating stakes for a round.
171#[derive(Clone, Copy, Serialize, Deserialize, Default, PartialEq, Eq, PartialOrd, Ord)]
172pub struct BlockRef {
173    pub round: Round,
174    pub author: AuthorityIndex,
175    pub digest: BlockDigest,
176}
177
178impl BlockRef {
179    pub const MIN: Self = Self {
180        round: 0,
181        author: AuthorityIndex::MIN,
182        digest: BlockDigest::MIN,
183    };
184
185    pub const MAX: Self = Self {
186        round: u32::MAX,
187        author: AuthorityIndex::MAX,
188        digest: BlockDigest::MAX,
189    };
190
191    pub fn new(round: Round, author: AuthorityIndex, digest: BlockDigest) -> Self {
192        Self {
193            round,
194            author,
195            digest,
196        }
197    }
198}
199
200impl fmt::Display for BlockRef {
201    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
202        write!(f, "B{}({},{})", self.round, self.author, self.digest)
203    }
204}
205
206impl fmt::Debug for BlockRef {
207    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
208        fmt::Display::fmt(self, f)
209    }
210}
211
212impl Hash for BlockRef {
213    fn hash<H: Hasher>(&self, state: &mut H) {
214        state.write(&self.digest.0[..8]);
215    }
216}
217
218/// Digest of a `VerifiedBlock` or verified `SignedBlock`, which covers the
219/// `Block` and its signature.
220///
221/// Note: the signature algorithm is assumed to be non-malleable, so it is
222/// impossible for another party to create an altered but valid signature,
223/// producing an equivocating `BlockDigest`.
224#[derive(Clone, Copy, Serialize, Deserialize, Default, PartialEq, Eq, PartialOrd, Ord)]
225pub struct BlockDigest([u8; consensus_config::DIGEST_LENGTH]);
226
227impl BlockDigest {
228    /// Lexicographic min & max digest.
229    pub const MIN: Self = Self([u8::MIN; consensus_config::DIGEST_LENGTH]);
230    pub const MAX: Self = Self([u8::MAX; consensus_config::DIGEST_LENGTH]);
231}
232
233impl Hash for BlockDigest {
234    fn hash<H: Hasher>(&self, state: &mut H) {
235        state.write(&self.0[..8]);
236    }
237}
238
239impl From<BlockDigest> for Digest<{ DIGEST_LENGTH }> {
240    fn from(hd: BlockDigest) -> Self {
241        Digest::new(hd.0)
242    }
243}
244
245impl fmt::Display for BlockDigest {
246    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
247        write!(
248            f,
249            "{}",
250            base64::Engine::encode(&base64::engine::general_purpose::STANDARD, self.0)
251                .get(0..4)
252                .ok_or(fmt::Error)?
253        )
254    }
255}
256
257impl fmt::Debug for BlockDigest {
258    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
259        write!(
260            f,
261            "{}",
262            base64::Engine::encode(&base64::engine::general_purpose::STANDARD, self.0)
263        )
264    }
265}
266
267impl AsRef<[u8]> for BlockDigest {
268    fn as_ref(&self) -> &[u8] {
269        &self.0
270    }
271}
272
273/// Slot is the position of blocks in the DAG. It can contain 0, 1 or multiple
274/// blocks from the same authority at the same round.
275#[derive(Clone, Copy, PartialEq, PartialOrd, Default, Hash)]
276pub struct Slot {
277    pub round: Round,
278    pub authority: AuthorityIndex,
279}
280
281impl Slot {
282    pub fn new(round: Round, authority: AuthorityIndex) -> Self {
283        Self { round, authority }
284    }
285
286    #[cfg(test)]
287    pub fn new_for_test(round: Round, authority: u32) -> Self {
288        Self {
289            round,
290            authority: AuthorityIndex::new_for_test(authority),
291        }
292    }
293}
294
295impl From<BlockRef> for Slot {
296    fn from(value: BlockRef) -> Self {
297        Slot::new(value.round, value.author)
298    }
299}
300
301impl fmt::Display for Slot {
302    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
303        write!(f, "S{}{}", self.round, self.authority)
304    }
305}
306
307impl fmt::Debug for Slot {
308    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
309        fmt::Display::fmt(&self, f)
310    }
311}
312
313/// A Block with its signature, before they are verified.
314///
315/// Note: `BlockDigest` is computed over this struct, so any added field
316/// (without `#[serde(skip)]`) will affect the values of `BlockDigest` and
317/// `BlockRef`.
318#[derive(Deserialize, Serialize)]
319pub(crate) struct SignedBlock {
320    inner: Block,
321    signature: Bytes,
322}
323
324impl SignedBlock {
325    /// Should only be used when constructing the genesis blocks
326    pub(crate) fn new_genesis(block: Block) -> Self {
327        Self {
328            inner: block,
329            signature: Bytes::default(),
330        }
331    }
332
333    pub(crate) fn new(block: Block, protocol_keypair: &ProtocolKeyPair) -> ConsensusResult<Self> {
334        let signature = compute_block_signature(&block, protocol_keypair)?;
335        Ok(Self {
336            inner: block,
337            signature: Bytes::copy_from_slice(signature.to_bytes()),
338        })
339    }
340
341    pub(crate) fn signature(&self) -> &Bytes {
342        &self.signature
343    }
344
345    /// This method only verifies this block's signature. Verification of the
346    /// full block should be done via BlockVerifier.
347    pub(crate) fn verify_signature(&self, context: &Context) -> ConsensusResult<()> {
348        let block = &self.inner;
349        let committee = &context.committee;
350        ensure!(
351            committee.is_valid_index(block.author()),
352            ConsensusError::InvalidAuthorityIndex {
353                index: block.author(),
354                max: committee.size() - 1
355            }
356        );
357        let authority = committee.authority(block.author());
358        verify_block_signature(block, self.signature(), &authority.protocol_key)
359    }
360
361    /// Serialises the block using the bcs serializer
362    pub(crate) fn serialize(&self) -> Result<Bytes, bcs::Error> {
363        let bytes = bcs::to_bytes(self)?;
364        Ok(bytes.into())
365    }
366
367    /// Clears signature for testing.
368    #[cfg(test)]
369    pub(crate) fn clear_signature(&mut self) {
370        self.signature = Bytes::default();
371    }
372}
373
374/// Digest of a block, covering all `Block` fields without its signature.
375/// This is used during Block signing and signature verification.
376/// This should never be used outside of this file, to avoid confusion with
377/// `BlockDigest`.
378#[derive(Serialize, Deserialize)]
379struct InnerBlockDigest([u8; consensus_config::DIGEST_LENGTH]);
380
381/// Computes the digest of a Block, only for signing and verifications.
382fn compute_inner_block_digest(block: &Block) -> ConsensusResult<InnerBlockDigest> {
383    let mut hasher = DefaultHashFunction::new();
384    hasher.update(bcs::to_bytes(block).map_err(ConsensusError::SerializationFailure)?);
385    Ok(InnerBlockDigest(hasher.finalize().into()))
386}
387
388/// Wrap a InnerBlockDigest in the intent message.
389fn to_consensus_block_intent(digest: InnerBlockDigest) -> IntentMessage<InnerBlockDigest> {
390    IntentMessage::new(Intent::consensus_app(IntentScope::ConsensusBlock), digest)
391}
392
393/// Process for signing & verying a block signature:
394/// 1. Compute the digest of `Block`.
395/// 2. Wrap the digest in `IntentMessage`.
396/// 3. Sign the serialized `IntentMessage`, or verify signature against it.
397fn compute_block_signature(
398    block: &Block,
399    protocol_keypair: &ProtocolKeyPair,
400) -> ConsensusResult<ProtocolKeySignature> {
401    let digest = compute_inner_block_digest(block)?;
402    let message = bcs::to_bytes(&to_consensus_block_intent(digest))
403        .map_err(ConsensusError::SerializationFailure)?;
404    Ok(protocol_keypair.sign(&message))
405}
406fn verify_block_signature(
407    block: &Block,
408    signature: &[u8],
409    protocol_pubkey: &ProtocolPublicKey,
410) -> ConsensusResult<()> {
411    let digest = compute_inner_block_digest(block)?;
412    let message = bcs::to_bytes(&to_consensus_block_intent(digest))
413        .map_err(ConsensusError::SerializationFailure)?;
414    let sig =
415        ProtocolKeySignature::from_bytes(signature).map_err(ConsensusError::MalformedSignature)?;
416    protocol_pubkey
417        .verify(&message, &sig)
418        .map_err(ConsensusError::SignatureVerificationFailure)
419}
420
421/// Allow quick access on the underlying Block without having to always refer to
422/// the inner block ref.
423impl Deref for SignedBlock {
424    type Target = Block;
425
426    fn deref(&self) -> &Self::Target {
427        &self.inner
428    }
429}
430
431/// VerifiedBlock allows full access to its content.
432/// Note: clone() is relatively cheap with most underlying data refcounted.
433#[derive(Clone)]
434pub struct VerifiedBlock {
435    block: Arc<SignedBlock>,
436
437    // Cached Block digest and serialized SignedBlock, to avoid re-computing these values.
438    digest: BlockDigest,
439    serialized: Bytes,
440}
441
442impl VerifiedBlock {
443    /// Creates VerifiedBlock from a verified SignedBlock and its serialized
444    /// bytes.
445    pub(crate) fn new_verified(signed_block: SignedBlock, serialized: Bytes) -> Self {
446        let digest = Self::compute_digest(&serialized);
447        VerifiedBlock {
448            block: Arc::new(signed_block),
449            digest,
450            serialized,
451        }
452    }
453
454    /// This method is public for testing in other crates.
455    pub fn new_for_test(block: Block) -> Self {
456        let signed_block = SignedBlock {
457            inner: block,
458            signature: Default::default(),
459        };
460        let serialized: Bytes = bcs::to_bytes(&signed_block)
461            .expect("Serialization should not fail")
462            .into();
463        let digest = Self::compute_digest(&serialized);
464        VerifiedBlock {
465            block: Arc::new(signed_block),
466            digest,
467            serialized,
468        }
469    }
470
471    /// Returns reference to the block.
472    pub fn reference(&self) -> BlockRef {
473        BlockRef {
474            round: self.round(),
475            author: self.author(),
476            digest: self.digest(),
477        }
478    }
479
480    pub(crate) fn digest(&self) -> BlockDigest {
481        self.digest
482    }
483
484    /// Returns the serialized block with signature.
485    pub(crate) fn serialized(&self) -> &Bytes {
486        &self.serialized
487    }
488
489    /// Computes digest from the serialized block with signature.
490    pub(crate) fn compute_digest(serialized: &[u8]) -> BlockDigest {
491        let mut hasher = DefaultHashFunction::new();
492        hasher.update(serialized);
493        BlockDigest(hasher.finalize().into())
494    }
495}
496
497/// Allow quick access on the underlying Block without having to always refer to
498/// the inner block ref.
499impl Deref for VerifiedBlock {
500    type Target = Block;
501
502    fn deref(&self) -> &Self::Target {
503        &self.block.inner
504    }
505}
506
507impl PartialEq for VerifiedBlock {
508    fn eq(&self, other: &Self) -> bool {
509        self.digest() == other.digest()
510    }
511}
512
513impl fmt::Display for VerifiedBlock {
514    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
515        write!(f, "{}", self.reference())
516    }
517}
518
519impl fmt::Debug for VerifiedBlock {
520    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
521        write!(
522            f,
523            "{:?}({}ms;{:?};{}t;{}c)",
524            self.reference(),
525            self.timestamp_ms(),
526            self.ancestors(),
527            self.transactions().len(),
528            self.commit_votes().len(),
529        )
530    }
531}
532
533/// Block with extended additional information, such as
534/// local blocks that are excluded from the block's ancestors.
535/// The extended information do not need to be certified or forwarded to other
536/// authorities.
537#[derive(Clone, Debug)]
538pub(crate) struct ExtendedBlock {
539    pub block: VerifiedBlock,
540    pub excluded_ancestors: Vec<BlockRef>,
541}
542
543/// Generates the genesis blocks for the current Committee.
544/// The blocks are returned in authority index order.
545pub(crate) fn genesis_blocks(context: Arc<Context>) -> Vec<VerifiedBlock> {
546    context
547        .committee
548        .authorities()
549        .map(|(authority_index, _)| {
550            let signed_block = SignedBlock::new_genesis(Block::V1(BlockV1::genesis_block(
551                context.committee.epoch(),
552                authority_index,
553            )));
554            let serialized = signed_block
555                .serialize()
556                .expect("Genesis block serialization failed.");
557            // Unnecessary to verify genesis blocks.
558            VerifiedBlock::new_verified(signed_block, serialized)
559        })
560        .collect::<Vec<VerifiedBlock>>()
561}
562
563/// This struct is public for testing in other crates.
564#[derive(Clone)]
565pub struct TestBlock {
566    block: BlockV1,
567}
568
569impl TestBlock {
570    pub fn new(round: Round, author: u32) -> Self {
571        Self {
572            block: BlockV1 {
573                round,
574                author: AuthorityIndex::new_for_test(author),
575                ..Default::default()
576            },
577        }
578    }
579
580    pub fn set_epoch(mut self, epoch: Epoch) -> Self {
581        self.block.epoch = epoch;
582        self
583    }
584
585    pub fn set_round(mut self, round: Round) -> Self {
586        self.block.round = round;
587        self
588    }
589
590    pub fn set_author(mut self, author: AuthorityIndex) -> Self {
591        self.block.author = author;
592        self
593    }
594
595    pub fn set_timestamp_ms(mut self, timestamp_ms: BlockTimestampMs) -> Self {
596        self.block.timestamp_ms = timestamp_ms;
597        self
598    }
599
600    pub fn set_ancestors(mut self, ancestors: Vec<BlockRef>) -> Self {
601        self.block.ancestors = ancestors;
602        self
603    }
604
605    pub fn set_transactions(mut self, transactions: Vec<Transaction>) -> Self {
606        self.block.transactions = transactions;
607        self
608    }
609
610    pub fn set_commit_votes(mut self, commit_votes: Vec<CommitVote>) -> Self {
611        self.block.commit_votes = commit_votes;
612        self
613    }
614
615    pub fn build(self) -> Block {
616        Block::V1(self.block)
617    }
618}
619
620/// A block can attach reports of misbehavior by other authorities.
621#[derive(Clone, Serialize, Deserialize, Debug)]
622pub struct MisbehaviorReport {
623    pub target: AuthorityIndex,
624    pub proof: MisbehaviorProof,
625}
626
627/// Proof of misbehavior are usually signed block(s) from the misbehaving
628/// authority.
629#[derive(Clone, Serialize, Deserialize, Debug)]
630pub enum MisbehaviorProof {
631    InvalidBlock(BlockRef),
632}
633
634// TODO: add basic verification for BlockRef and BlockDigest.
635// TODO: add tests for SignedBlock and VerifiedBlock conversion.
636
637#[cfg(test)]
638mod tests {
639    use std::sync::Arc;
640
641    use fastcrypto::error::FastCryptoError;
642
643    use crate::{
644        block::{SignedBlock, TestBlock},
645        context::Context,
646        error::ConsensusError,
647    };
648
649    #[tokio::test]
650    async fn test_sign_and_verify() {
651        let (context, key_pairs) = Context::new_for_test(4);
652        let context = Arc::new(context);
653
654        // Create a block that authority 2 has created
655        let block = TestBlock::new(10, 2).build();
656
657        // Create a signed block with authority's 2 private key
658        let author_two_key = &key_pairs[2].1;
659        let signed_block = SignedBlock::new(block, author_two_key).expect("Shouldn't fail signing");
660
661        // Now verify the block's signature
662        let result = signed_block.verify_signature(&context);
663        assert!(result.is_ok());
664
665        // Try to sign authority's 2 block with authority's 1 key
666        let block = TestBlock::new(10, 2).build();
667        let author_one_key = &key_pairs[1].1;
668        let signed_block = SignedBlock::new(block, author_one_key).expect("Shouldn't fail signing");
669
670        // Now verify the block, it should fail
671        let result = signed_block.verify_signature(&context);
672        match result.err().unwrap() {
673            ConsensusError::SignatureVerificationFailure(err) => {
674                assert_eq!(err, FastCryptoError::InvalidSignature);
675            }
676            err => panic!("Unexpected error: {err:?}"),
677        }
678    }
679}
consensus_core/block.rs

consensus_core/
block.rs
