ch.epfl.dedis.calypso

Class WriteData

java.lang.Object

ch.epfl.dedis.calypso.WriteData

public class WriteData
extends Object

A WriteData is the data that is sent to the calypsoWrite contract store a write request with the encrypted document. Stored on BzyCoin, it will have the following fields:

- EncData - the encrypted data, should be smaller than 8MB - U, Ubar, E, F, Cs - the symmetric key used to encrypt the data, itself encrypted to the Long Term Secret key - ExtraData - plain text data that is stored as-is on the ledger - LTSID - the Long Term Secret ID used to encrypt the data

Constructor Summary

Constructors

Constructor and Description
WriteData(LTS lts, byte[] dataEnc, byte[] keyMaterial, byte[] extraData, DarcId publisher) Create a new document by giving all possible parameters.

Method Summary

Modifier and Type	Method and Description
static WriteData	fromByzcoin(ByzCoinRPC bc, InstanceId id) Recreates a WriteData from an instanceid.
static WriteData	fromInstance(Instance inst) Recreates a WriteData from an instance.
byte[]	getDataEnc() Get the encrypted data.
byte[]	getExtraData() Get the extra data.
Calypso.Write	getWrite()

Methods inherited from class java.lang.Object

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

Constructor Detail

WriteData

public WriteData(LTS lts,
                 byte[] dataEnc,
                 byte[] keyMaterial,
                 byte[] extraData,
                 DarcId publisher)
          throws CothorityException

Create a new document by giving all possible parameters. This call supposes that the data sent here is already encrypted using the keyMaterial and can be decrypted using keyMaterial.

Parameters:

lts - Long Term Secret parameters

dataEnc - The ciphertext which will be stored _as is_ on ByzCoin.

keyMaterial - The symmetric key plus eventually an IV. This will be encrypted under the shared symmetricKey of the cothority.

extraData - data that will _not be encrypted_ but will be visible in cleartext on ByzCoin.

publisher - The darc with a rule for calypsoWrite and calypsoRead.

Throws:

CothorityException

Method Detail

fromByzcoin

public static WriteData fromByzcoin(ByzCoinRPC bc,
                                    InstanceId id)
                             throws CothorityNotFoundException,
                                    CothorityCommunicationException

Recreates a WriteData from an instanceid.

Parameters:

bc - a running Byzcoin service

id - an instanceId of a WriteInstance

Throws:

com.google.protobuf.InvalidProtocolBufferException

CothorityNotFoundException

CothorityCommunicationException

fromInstance

public static WriteData fromInstance(Instance inst)
                              throws CothorityNotFoundException

Recreates a WriteData from an instance.

Parameters:

inst - an instance representing a WriteData

Returns:

WriteData

Throws:

CothorityNotFoundException

getDataEnc

public byte[] getDataEnc()

Get the encrypted data.

getExtraData

public byte[] getExtraData()

Get the extra data.

getWrite

public Calypso.Write getWrite()