signature

Documentation

Index

• func NewRandomBeaconInspector(groupPublicKey crypto.PublicKey, publicKeyShares []crypto.PublicKey, ...) (*randomBeaconInspector, error)
• type ConsensusSigDataPacker
  • func NewConsensusSigDataPacker(committees hotstuff.Committee) *ConsensusSigDataPacker
  • func (p *ConsensusSigDataPacker) Pack(blockID flow.Identifier, sig *hotstuff.BlockSignatureData) ([]byte, []byte, error)
  • func (p *ConsensusSigDataPacker) Unpack(signerIdentities flow.IdentityList, sigData []byte) (*hotstuff.BlockSignatureData, error)
• type EpochAwareRandomBeaconKeyStore
  • func NewEpochAwareRandomBeaconKeyStore(epochLookup module.EpochLookup, keys storage.SafeBeaconKeys) *EpochAwareRandomBeaconKeyStore
  • func (s *EpochAwareRandomBeaconKeyStore) ByView(view uint64) (crypto.PrivateKey, error)
• type RandomBeaconReconstructor
  • func NewRandomBeaconReconstructor(dkg hotstuff.DKG, randomBeaconInspector hotstuff.RandomBeaconInspector) *RandomBeaconReconstructor
  • func (r *RandomBeaconReconstructor) TrustedAdd(signerID flow.Identifier, sig crypto.Signature) (bool, error)
  • func (r *RandomBeaconReconstructor) Verify(signerID flow.Identifier, sig crypto.Signature) error
• type StaticRandomBeaconSignerStore
  • func NewStaticRandomBeaconSignerStore(beaconKey crypto.PrivateKey) *StaticRandomBeaconSignerStore
  • func (s *StaticRandomBeaconSignerStore) ByView(_ uint64) (crypto.PrivateKey, error)
• type WeightedSignatureAggregator
  • func NewWeightedSignatureAggregator(ids flow.IdentityList, pks []crypto.PublicKey, message []byte, dsTag string) (*WeightedSignatureAggregator, error)
  • func (w *WeightedSignatureAggregator) Aggregate() ([]flow.Identifier, []byte, error)
  • func (w *WeightedSignatureAggregator) TotalWeight() uint64
  • func (w *WeightedSignatureAggregator) TrustedAdd(signerID flow.Identifier, sig crypto.Signature) (uint64, error)
  • func (w *WeightedSignatureAggregator) Verify(signerID flow.Identifier, sig crypto.Signature) error

Functions

func NewRandomBeaconInspector

func NewRandomBeaconInspector(
	groupPublicKey crypto.PublicKey,
	publicKeyShares []crypto.PublicKey,
	threshold int,
	message []byte,
) (*randomBeaconInspector, error)

NewRandomBeaconInspector instantiates a new randomBeaconInspector. The constructor errors with a `model.ConfigurationError` in any of the following cases

• n is not between `ThresholdSignMinSize` and `ThresholdSignMaxSize`, for n the number of participants `n := len(publicKeyShares)`
• threshold value is not in interval [1, n-1]
• any input public key is not a BLS key

Types

type ConsensusSigDataPacker

type ConsensusSigDataPacker struct {
	model.SigDataPacker
	// contains filtered or unexported fields
}

ConsensusSigDataPacker implements the hotstuff.Packer interface. The encoding method is RLP.

func NewConsensusSigDataPacker

func NewConsensusSigDataPacker(committees hotstuff.Committee) *ConsensusSigDataPacker

NewConsensusSigDataPacker creates a new ConsensusSigDataPacker instance

func (*ConsensusSigDataPacker) Pack

func (p *ConsensusSigDataPacker) Pack(blockID flow.Identifier, sig *hotstuff.BlockSignatureData) ([]byte, []byte, error)

Pack serializes the block signature data into raw bytes, suitable to create a QC. To pack the block signature data, we first build a compact data type, and then encode it into bytes. Expected error returns during normal operations:

• none; all errors are symptoms of inconsistent input data or corrupted internal state.

func (*ConsensusSigDataPacker) Unpack

func (p *ConsensusSigDataPacker) Unpack(signerIdentities flow.IdentityList, sigData []byte) (*hotstuff.BlockSignatureData, error)

Unpack de-serializes the provided signature data. sig is the aggregated signature data It returns:

• (sigData, nil) if successfully unpacked the signature data
• (nil, model.InvalidFormatError) if failed to unpack the signature data

type EpochAwareRandomBeaconKeyStore

type EpochAwareRandomBeaconKeyStore struct {
	// contains filtered or unexported fields
}

EpochAwareRandomBeaconKeyStore provides an abstraction to query random beacon private key for a given view. Internally it indexes and caches the private keys by epoch.

func NewEpochAwareRandomBeaconKeyStore

func NewEpochAwareRandomBeaconKeyStore(epochLookup module.EpochLookup, keys storage.SafeBeaconKeys) *EpochAwareRandomBeaconKeyStore

func (*EpochAwareRandomBeaconKeyStore) ByView

func (s *EpochAwareRandomBeaconKeyStore) ByView(view uint64) (crypto.PrivateKey, error)

ByView returns the random beacon signer for signing objects at a given view. The view determines the epoch, which determines the DKG private key underlying the signer. It returns:

• (signer, nil) if DKG succeeded locally in the epoch of the view, signer is not nil
• (nil, protocol.ErrEpochNotCommitted) if no epoch found for given view
• (nil, DKGFailError) if DKG failed locally in the epoch of the view
• (nil, error) if there is any exception

type RandomBeaconReconstructor

type RandomBeaconReconstructor struct {
	hotstuff.RandomBeaconInspector // a stateful object for this epoch. It's used for both verifying all sig shares and reconstructing the threshold signature.
	// contains filtered or unexported fields
}

RandomBeaconReconstructor implements hotstuff.RandomBeaconReconstructor. The implementation wraps the hotstuff.RandomBeaconInspector and translates the signer identity into signer index. It has knowledge about DKG to be able to map signerID to signerIndex

func NewRandomBeaconReconstructor

func NewRandomBeaconReconstructor(dkg hotstuff.DKG, randomBeaconInspector hotstuff.RandomBeaconInspector) *RandomBeaconReconstructor

func (*RandomBeaconReconstructor) TrustedAdd

func (r *RandomBeaconReconstructor) TrustedAdd(signerID flow.Identifier, sig crypto.Signature) (bool, error)

TrustedAdd adds a share to the internal signature shares store. There is no pre-check of the signature's validity _before_ adding it. It is the caller's responsibility to make sure the signature was previously verified. Nevertheless, the implementation guarantees safety (only correct threshold signatures are returned) through a post-check (verifying the threshold signature _after_ reconstruction before returning it). The function is thread-safe but locks its internal state, thereby permitting only one routine at a time to add a signature. Returns:

• (true, nil) if the signature has been added, and enough shares have been collected.
• (false, nil) if the signature has been added, but not enough shares were collected.
• (false, error) if there is any exception adding the signature share.
• model.InvalidSignerError if signerIndex is invalid (out of the valid range)
• model.DuplicatedSignerError if the signer has been already added
• other error if there is an unexpected exception.

func (*RandomBeaconReconstructor) Verify

func (r *RandomBeaconReconstructor) Verify(signerID flow.Identifier, sig crypto.Signature) error

Verify verifies the signature share under the signer's public key and the message agreed upon. The function is thread-safe and wait-free (i.e. allowing arbitrary many routines to execute the business logic, without interfering with each other). It allows concurrent verification of the given signature. Returns :

• model.InvalidSignerError if signerID is invalid
• model.ErrInvalidSignature if signerID is valid but signature is cryptographically invalid
• other error if there is an unexpected exception.

type StaticRandomBeaconSignerStore

type StaticRandomBeaconSignerStore struct {
	// contains filtered or unexported fields
}

StaticRandomBeaconSignerStore is a simple implementation of module.RandomBeaconKeyStore that returns same key for each view. This structure was implemented for bootstrap process and should be used only for it.

func NewStaticRandomBeaconSignerStore

func NewStaticRandomBeaconSignerStore(beaconKey crypto.PrivateKey) *StaticRandomBeaconSignerStore

func (*StaticRandomBeaconSignerStore) ByView

func (s *StaticRandomBeaconSignerStore) ByView(_ uint64) (crypto.PrivateKey, error)

type WeightedSignatureAggregator

type WeightedSignatureAggregator struct {
	// contains filtered or unexported fields
}

WeightedSignatureAggregator implements consensus/hotstuff.WeightedSignatureAggregator. It is a wrapper around signature.SignatureAggregatorSameMessage, which implements a mapping from node IDs (as used by HotStuff) to index-based addressing of authorized signers (as used by SignatureAggregatorSameMessage).

func NewWeightedSignatureAggregator

func NewWeightedSignatureAggregator(
	ids flow.IdentityList,
	pks []crypto.PublicKey,
	message []byte,
	dsTag string,
) (*WeightedSignatureAggregator, error)

NewWeightedSignatureAggregator returns a weighted aggregator initialized with a list of flow identities, their respective public keys, a message and a domain separation tag. The identities represent the list of all possible signers. The constructor errors if: - the list of identities is empty - if the length of keys does not match the length of identities - if one of the keys is not a valid public key.

A weighted aggregator is used for one aggregation only. A new instance should be used for each signature aggregation task in the protocol.

func (*WeightedSignatureAggregator) Aggregate

func (w *WeightedSignatureAggregator) Aggregate() ([]flow.Identifier, []byte, error)

Aggregate aggregates the signatures and returns the aggregated signature. The function performs a final verification and errors if the aggregated signature is not valid. This is required for the function safety since "TrustedAdd" allows adding invalid signatures. The function errors with:

• model.InsufficientSignaturesError if no signatures have been added yet
• model.InvalidSignatureIncludedError if some signature(s), included via TrustedAdd, are invalid

The function is thread-safe.

TODO : When compacting the list of signers, update the return from []flow.Identifier

to a compact bit vector.

func (*WeightedSignatureAggregator) TotalWeight

func (w *WeightedSignatureAggregator) TotalWeight() uint64

TotalWeight returns the total weight presented by the collected signatures. The function is thread-safe

func (*WeightedSignatureAggregator) TrustedAdd

func (w *WeightedSignatureAggregator) TrustedAdd(signerID flow.Identifier, sig crypto.Signature) (uint64, error)

TrustedAdd adds a signature to the internal set of signatures and adds the signer's weight to the total collected weight, iff the signature is _not_ a duplicate.

The total weight of all collected signatures (excluding duplicates) is returned regardless of any returned error. The function errors with:

• model.InvalidSignerError if signerID is invalid (not a consensus participant)
• model.DuplicatedSignerError if the signer has been already added

The function is thread-safe.

func (*WeightedSignatureAggregator) Verify

func (w *WeightedSignatureAggregator) Verify(signerID flow.Identifier, sig crypto.Signature) error

Verify verifies the signature under the stored public keys and message. Expected errors during normal operations:

• model.InvalidSignerError if signerID is invalid (not a consensus participant)
• model.ErrInvalidSignature if signerID is valid but signature is cryptographically invalid

The function is thread-safe.