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Introduce AttestationValidationContext

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This reduced code duplication.
This commit is contained in:
Paul Hauner 2018-09-30 16:09:35 +09:30
parent b426c9e724
commit c3ec8a3407
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GPG Key ID: 303E4494BB28068C
4 changed files with 141 additions and 129 deletions
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2
lighthouse/state/attestation_record/mod.rs
View File

@ -19,6 +19,6 @@ pub use self::ssz_splitter::{
AttestationSplitError,
};
pub use self::validation::{
validate_attestation,
AttestationValidationContext,
AttestationValidationError,
};

225
lighthouse/state/attestation_record/validation/attestation_validation.rs
View File

@ -45,114 +45,133 @@ pub enum AttestationValidationError {
DBError(String),
}
pub fn validate_attestation<T>(a: &AttestationRecord,
block_slot: u64,
cycle_length: u8,
known_last_justified_slot: u64,
known_parent_hashes: &Arc<Vec<Hash256>>,
block_store: &Arc<BlockStore<T>>,
validator_store: &Arc<ValidatorStore<T>>,
attester_map: &Arc<AttesterMap>)
-> Result<Option<HashSet<usize>>, AttestationValidationError>
pub struct AttestationValidationContext<T>
where T: ClientDB + Sized
{
/*
* The attesation slot must not be higher than the block that contained it.
*/
if a.slot > block_slot {
return Err(AttestationValidationError::SlotTooHigh);
}
pub block_slot: u64,
pub cycle_length: u8,
pub last_justified_slot: u64,
pub parent_hashes: Arc<Vec<Hash256>>,
pub block_store: Arc<BlockStore<T>>,
pub validator_store: Arc<ValidatorStore<T>>,
pub attester_map: Arc<AttesterMap>,
}
/*
* The slot of this attestation must not be more than cycle_length + 1 distance
* from the block that contained it.
*
* The below code stays overflow-safe as long as cycle length is a < 64 bit integer.
*/
if a.slot < block_slot.saturating_sub(u64::from(cycle_length) + 1) {
return Err(AttestationValidationError::SlotTooLow);
}
/*
* The attestation must indicate that its last justified slot is the same as the last justified
* slot known to us.
*/
if a.justified_slot > known_last_justified_slot {
return Err(AttestationValidationError::JustifiedSlotTooHigh);
}
/*
* There is no need to include more oblique parents hashes than there are blocks
* in a cycle.
*/
if a.oblique_parent_hashes.len() > usize::from(cycle_length) {
return Err(AttestationValidationError::TooManyObliqueHashes);
}
/*
* Retrieve the set of attestation indices for this slot and shard id.
*
* This is an array mapping the order that validators will appear in the bitfield to the
* canonincal index of a validator.
*/
let attestation_indices = attester_map.get(&(a.slot, a.shard_id))
.ok_or(AttestationValidationError::BadAttesterMap)?;
/*
* The bitfield must be no longer than the minimum required to represent each validator in the
* attestation indicies for this slot and shard id.
*/
if a.attester_bitfield.num_bytes() !=
bytes_for_bits(attestation_indices.len())
impl<T> AttestationValidationContext<T>
where T: ClientDB
{
pub fn validate_attestation(&self, a: &AttestationRecord)
/*
block_slot: u64,
cycle_length: u8,
known_last_justified_slot: u64,
known_parent_hashes: &Arc<Vec<Hash256>>,
block_store: &Arc<BlockStore<T>>,
validator_store: &Arc<ValidatorStore<T>>,
attester_map: &Arc<AttesterMap>)
*/
-> Result<Option<HashSet<usize>>, AttestationValidationError>
where T: ClientDB + Sized
{
return Err(AttestationValidationError::BadBitfieldLength);
/*
* The attesation slot must not be higher than the block that contained it.
*/
if a.slot > self.block_slot {
return Err(AttestationValidationError::SlotTooHigh);
}
/*
* The slot of this attestation must not be more than cycle_length + 1 distance
* from the block that contained it.
*
* The below code stays overflow-safe as long as cycle length is a < 64 bit integer.
*/
if a.slot < self.block_slot
.saturating_sub(u64::from(self.cycle_length).saturating_add(1)) {
return Err(AttestationValidationError::SlotTooLow);
}
/*
* The attestation must indicate that its last justified slot is the same as the last justified
* slot known to us.
*/
if a.justified_slot > self.last_justified_slot {
return Err(AttestationValidationError::JustifiedSlotTooHigh);
}
/*
* There is no need to include more oblique parents hashes than there are blocks
* in a cycle.
*/
if a.oblique_parent_hashes.len() > usize::from(self.cycle_length) {
return Err(AttestationValidationError::TooManyObliqueHashes);
}
/*
* Retrieve the set of attestation indices for this slot and shard id.
*
* This is an array mapping the order that validators will appear in the bitfield to the
* canonincal index of a validator.
*/
let attestation_indices = self.attester_map.get(&(a.slot, a.shard_id))
.ok_or(AttestationValidationError::BadAttesterMap)?;
/*
* The bitfield must be no longer than the minimum required to represent each validator in the
* attestation indicies for this slot and shard id.
*/
if a.attester_bitfield.num_bytes() !=
bytes_for_bits(attestation_indices.len())
{
return Err(AttestationValidationError::BadBitfieldLength);
}
/*
* If there are excess bits in the bitfield because the number of a validators in not a
* multiple of 8, reject this attestation record.
*
* Allow extra set bits would permit mutliple different byte layouts (and therefore hashes) to
* refer to the same AttesationRecord.
*/
let last_byte =
a.attester_bitfield.get_byte(a.attester_bitfield.num_bytes() - 1)
.ok_or(AttestationValidationError::InvalidBitfield)?;
if any_of_last_n_bits_are_set(*last_byte, a.attester_bitfield.len() % 8) {
return Err(AttestationValidationError::InvalidBitfieldEndBits)
}
/*
* The specified justified block hash must be known to us
*/
if !self.block_store.block_exists(&a.justified_block_hash)? {
return Err(AttestationValidationError::UnknownJustifiedBlock)
}
let signed_message = {
let parent_hashes = attestation_parent_hashes(
self.cycle_length,
self.block_slot,
a.slot,
&self.parent_hashes,
&a.oblique_parent_hashes)?;
generate_signed_message(
a.slot,
&parent_hashes,
a.shard_id,
&a.shard_block_hash,
a.justified_slot)
};
let voted_hashmap =
verify_aggregate_signature_for_indices(
&signed_message,
&a.aggregate_sig,
&attestation_indices,
&a.attester_bitfield,
&self.validator_store)?;
Ok(voted_hashmap)
}
/*
* If there are excess bits in the bitfield because the number of a validators in not a
* multiple of 8, reject this attestation record.
*
* Allow extra set bits would permit mutliple different byte layouts (and therefore hashes) to
* refer to the same AttesationRecord.
*/
let last_byte =
a.attester_bitfield.get_byte(a.attester_bitfield.num_bytes() - 1)
.ok_or(AttestationValidationError::InvalidBitfield)?;
if any_of_last_n_bits_are_set(*last_byte, a.attester_bitfield.len() % 8) {
return Err(AttestationValidationError::InvalidBitfieldEndBits)
}
/*
* The specified justified block hash must be known to us
*/
if !block_store.block_exists(&a.justified_block_hash)? {
return Err(AttestationValidationError::UnknownJustifiedBlock)
}
let signed_message = {
let parent_hashes = attestation_parent_hashes(
cycle_length,
block_slot,
a.slot,
&known_parent_hashes,
&a.oblique_parent_hashes)?;
generate_signed_message(
a.slot,
&parent_hashes,
a.shard_id,
&a.shard_block_hash,
a.justified_slot)
};
let voted_hashmap =
verify_aggregate_signature_for_indices(
&signed_message,
&a.aggregate_sig,
&attestation_indices,
&a.attester_bitfield,
&validator_store)?;
Ok(voted_hashmap)
}
fn bytes_for_bits(bits: usize) -> usize {

2
lighthouse/state/attestation_record/validation/mod.rs
View File

@ -11,6 +11,6 @@ mod signature_verification;
mod message_generation;
pub use self::attestation_validation::{
validate_attestation,
AttestationValidationContext,
AttestationValidationError,
};

41
lighthouse/state/block/validation/validate_ssz_block.rs
View File

@ -7,7 +7,7 @@ use std::sync::{
RwLock,
};
use super::attestation_record::{
validate_attestation,
AttestationValidationContext,
AttestationValidationError,
};
use super::attestation_record::{
@ -99,10 +99,6 @@ impl<T> BlockValidationContext<T>
/// a suspicion that the block might be invalid. Such a suspicion should be applied to
/// all blocks coming from the network.
///
/// Of course, this function will only be more efficient if a block is already serialized.
/// Serializing a complete block and then validating with this function will be less
/// efficient than just validating the original block.
///
/// This function will determine if the block is new, already known or invalid (either
/// intrinsically or due to some application error.)
///
@ -183,18 +179,24 @@ impl<T> BlockValidationContext<T>
return Err(SszBlockValidationError::ProposerAttestationHasObliqueHashes);
}
/*
* Generate the context in which attestations will be validated.
*/
let attestation_validation_context = Arc::new(AttestationValidationContext {
block_slot,
cycle_length: self.cycle_length,
last_justified_slot: self.last_justified_slot,
parent_hashes: self.parent_hashes.clone(),
block_store: self.block_store.clone(),
validator_store: self.validator_store.clone(),
attester_map: self.attester_map.clone(),
});
/*
* Validate this first attestation.
*/
let attestation_voters = validate_attestation(
&first_attestation,
block_slot,
self.cycle_length,
self.last_justified_slot,
&self.parent_hashes,
&self.block_store,
&self.validator_store,
&self.attester_map)?;
let attestation_voters = attestation_validation_context
.validate_attestation(&first_attestation)?;
/*
* If the set of voters is None, the attestation was invalid.
@ -274,16 +276,7 @@ impl<T> BlockValidationContext<T>
* Deserialization succeeded and the attestation should be validated.
*/
Ok((attestation, _)) => {
let result = validate_attestation(
&attestation,
block_slot,
self.cycle_length,
self.last_justified_slot,
&self.parent_hashes,
&self.block_store,
&self.validator_store,
&self.attester_map);
match result {
match attestation_validation_context.validate_attestation(&attestation) {
/*
* Attestation validation failed with some error.
*/