ch.epfl.dedis.calypso

Class ReadInstance

java.lang.Object

ch.epfl.dedis.calypso.ReadInstance

public class ReadInstance
extends Object

ReadInstance represents a contract created by the calypsoRead contract.

Field Summary

Fields

Modifier and Type	Field and Description
static String	ContractId

Constructor Summary

Constructors

Constructor and Description
ReadInstance(CalypsoRPC calypso, WriteInstance write, List<Signer> signers, List<Long> signerCtrs, Point Xc) Create a new ReadInstance to request access to an encrypted document.

Method Summary

Modifier and Type	Method and Description
byte[]	decryptKeyMaterial(Scalar reader) Decrypts the key material by creating the read and write proofs necessary for the LTS to allow a re-encryption to the public key stored in the read request.
static ReadInstance	fromByzCoin(CalypsoRPC calypso, InstanceId id) Constructor used to connect to an existing instance.
Instance	getInstance() Get the instance object.
ReadData	getRead()

Methods inherited from class java.lang.Object

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

Field Detail

ContractId

public static String ContractId

Constructor Detail

ReadInstance

public ReadInstance(CalypsoRPC calypso,
                    WriteInstance write,
                    List<Signer> signers,
                    List<Long> signerCtrs,
                    Point Xc)
             throws CothorityException

Create a new ReadInstance to request access to an encrypted document. This call will send a transaction to ByzCoin and wait for it to be accepted or rejected. The key to re-encrypt to is taken in an argument

Parameters:

calypso - The CalypsoRPC object.

write - The write instance where a new read instance should be spawned from.

signers - Signers who are allowed to spawn a new instance.

signerCtrs - a list of monotonically increasing counter for every signer

Xc - is the key to which the dataEnc will be re-encrypted to, it must not be one of the signers

Throws:

CothorityException - if something goes wrong

Method Detail

getInstance

public Instance getInstance()

Get the instance object.

Returns:

the Instance

getRead

public ReadData getRead()
                 throws CothorityNotFoundException

Returns:

the readData stored in this instance.

Throws:

CothorityNotFoundException - if the requested instance cannot be found

decryptKeyMaterial

public byte[] decryptKeyMaterial(Scalar reader)
                          throws CothorityException

Decrypts the key material by creating the read and write proofs necessary for the LTS to allow a re-encryption to the public key stored in the read request.

Parameters:

reader - is the corresponding private key of the public

Returns:

the key material

Throws:

CothorityException - if something goes wrong

fromByzCoin

public static ReadInstance fromByzCoin(CalypsoRPC calypso,
                                       InstanceId id)
                                throws CothorityException

Constructor used to connect to an existing instance.

Parameters:

calypso - The CalypsoRPC object.

id - The id of the instance.

Returns:

the new ReadInstance

Throws:

CothorityException - if something goes wrong