/**
* Creates a Credential Revocation Information object
*
* @param key Private key
* @param unrevokedHandles Array of unrevoked revocation handles
* @param epoch The counter (representing a time window) in which this CRI is valid
* @param alg Revocation algorithm
* @return CredentialRevocationInformation object
*/
public static CredentialRevocationInformation CreateCRI(KeyPair key, BIG[] unrevokedHandles, int epoch, RevocationAlgorithm alg)
{
CredentialRevocationInformation cr = new CredentialRevocationInformation();
cr.RevocationAlg = (int)alg;
cr.Epoch = epoch;
// Create epoch key
WeakBB.KeyPair keyPair = WeakBB.WeakBBKeyGen();
if (alg == RevocationAlgorithm.ALG_NO_REVOCATION)
{
// Dummy PK in the proto
cr.EpochPk = IdemixUtils.GenG2.ToProto();
}
else
{
// Real PK only if we are going to use it
cr.EpochPk = keyPair.Pk.ToProto();
}
// Sign epoch + epoch key with the long term key
byte[] signed;
try
{
signed = key.Sign(cr.ToByteArray(), "SHA256withECDSA");
cr.EpochPkSig = ByteString.CopyFrom(signed);
}
catch (Exception e)
{
throw new CryptoException("Error processing the signature: ", e);
}
if (alg == RevocationAlgorithm.ALG_NO_REVOCATION)
{
// build and return the credential information object
return(cr);
}
// If alg not supported, return null
throw new ArgumentException("Algorithm " + alg.ToString() + " not supported");
}
