private void init(ASN1ObjectIdentifier keyAgreementOID) throws CMSException {
if (random == null) {
random = new SecureRandom();
}
if (keyAgreementOID.equals(CMSAlgorithm.ECMQV_SHA1KDF)) {
if (ephemeralKP == null) {
try {
ECParameterSpec ecParamSpec = ((ECPublicKey) senderPublicKey).getParams();
KeyPairGenerator ephemKPG = helper.createKeyPairGenerator(keyAgreementOID);
ephemKPG.initialize(ecParamSpec, random);
ephemeralKP = ephemKPG.generateKeyPair();
} catch (InvalidAlgorithmParameterException e) {
throw new CMSException(
"cannot determine MQV ephemeral key pair parameters from public key: " + e);
}
}
}
}
