ch.epfl.dedis.byzcoin

Class Proof

java.lang.Object

ch.epfl.dedis.byzcoin.Proof

public class Proof
extends Object

Proof represents a key/value entry in the collection and the path to the root node.

Constructor Summary

Constructors

Constructor and Description
Proof(ByzCoinProto.Proof p) Creates a new proof given a protobuf-representation.

Method Summary

Modifier and Type	Method and Description
String	getContractID()
DarcId	getDarcID()
Instance	getInstance()
byte[]	getKey()
SkipBlock	getLatest() accessor for the skipblock assocaited with this proof.
byte[]	getValue()
List<byte[]>	getValues()
boolean	isByzCoinProof()
boolean	isContract(String expected)
boolean	isContract(String expected, SkipblockId id) Checks if the proof is valid and of type expected.
boolean	matches()
ByzCoinProto.Proof	toProto() Get the protobuf representation of the proof.
boolean	verify(SkipblockId id) Verifies the proof with regard to the root id.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Proof

public Proof(ByzCoinProto.Proof p)

Creates a new proof given a protobuf-representation.

Parameters:

p - the protobuf-representation of the proof

Method Detail

getInstance

public Instance getInstance()
                     throws CothorityNotFoundException

Returns:

the instance stored in this proof - it will not verify if the proof is valid!

Throws:

CothorityNotFoundException - if the requested instance cannot be found

toProto

public ByzCoinProto.Proof toProto()

Get the protobuf representation of the proof.

Returns:

the protobuf representation of the proof

getLatest

public SkipBlock getLatest()

accessor for the skipblock assocaited with this proof.

Returns:

SkipBlock

verify

public boolean verify(SkipblockId id)
               throws CothorityException

Verifies the proof with regard to the root id. It will follow all steps and make sure that the hashes work out, starting from the leaf. At the end it will verify against the root hash to make sure that the inclusion proof is correct.

Parameters:

id - the skipblock to verify

Returns:

true if all checks verify, false if there is a mismatch in the hashes

Throws:

CothorityException - if something goes wrong

matches

public boolean matches()

Returns:

true if the proof has the key/value pair stored, false if it is a proof of absence.

getKey

public byte[] getKey()

Returns:

the key of the leaf node

getValues

public List<byte[]> getValues()

Returns:

the list of values in the leaf node.

getValue

public byte[] getValue()

Returns:

the value of the proof.

getContractID

public String getContractID()

Returns:

the string of the contractID.

getDarcID

public DarcId getDarcID()
                 throws CothorityCryptoException

Returns:

the darcID defining the access rules to the instance.

Throws:

CothorityCryptoException - if there's a problem with the cryptography

isByzCoinProof

public boolean isByzCoinProof()

Returns:

true if this looks like a matching proof for byzcoin.

isContract

public boolean isContract(String expected)

Parameters:

expected - the string of the expected contract.

Returns:

true if this is a matching byzcoin proof for a contract of the given contract.

isContract

public boolean isContract(String expected,
                          SkipblockId id)
                   throws CothorityException

Checks if the proof is valid and of type expected.

Parameters:

expected - the expected contractId

id - the Byzcoin id to verify the proof against

Returns:

true if the proof is correct with regard to that Byzcoin id and the contract is of the expected type.

Throws:

CothorityException - if something goes wrong