public static AsymmetricKeyParameter CreateKey(PrivateKeyInfo keyInfo)
{
AlgorithmIdentifier algId = keyInfo.getAlgorithmId();
if (algId.getObjectId().Equals(PKCSObjectIdentifiers.rsaEncryption))
{
RSAPrivateKeyStructure keyStructure = new RSAPrivateKeyStructure((ASN1Sequence)keyInfo.getPrivateKey());
return(new RSAPrivateCrtKeyParameters(
keyStructure.getModulus(),
keyStructure.getPublicExponent(),
keyStructure.getPrivateExponent(),
keyStructure.getPrime1(),
keyStructure.getPrime2(),
keyStructure.getExponent1(),
keyStructure.getExponent2(),
keyStructure.getCoefficient()));
}
else if (algId.getObjectId().Equals(PKCSObjectIdentifiers.dhKeyAgreement))
{
DHParameter para = new DHParameter((ASN1Sequence)keyInfo.getAlgorithmId().getParameters());
DERInteger derX = (DERInteger)keyInfo.getPrivateKey();
return(new DHPrivateKeyParameters(derX.getValue(), new DHParameters(para.getP(), para.getG())));
}
else if (algId.getObjectId().Equals(OIWObjectIdentifiers.elGamalAlgorithm))
{
ElGamalParameter para = new ElGamalParameter((ASN1Sequence)keyInfo.getAlgorithmId().getParameters());
DERInteger derX = (DERInteger)keyInfo.getPrivateKey();
return(new ElGamalPrivateKeyParameters(derX.getValue(), new ElGamalParameters(para.getP(), para.getG())));
}
else if (algId.getObjectId().Equals(X9ObjectIdentifiers.id_dsa))
{
DSAParameter para = new DSAParameter((ASN1Sequence)keyInfo.getAlgorithmId().getParameters());
DERInteger derX = (DERInteger)keyInfo.getPrivateKey();
return(new DSAPrivateKeyParameters(derX.getValue(), new DSAParameters(para.getP(), para.getQ(), para.getG())));
}
else if (algId.getObjectId().Equals(X9ObjectIdentifiers.id_ecPublicKey))
{
X962Parameters para = new X962Parameters((ASN1Object)keyInfo.getAlgorithmId().getParameters());
ECDomainParameters dParams = null;
if (para.isNamedCurve())
{
DERObjectIdentifier oid = (DERObjectIdentifier)para.getParameters();
X9ECParameters ecP = X962NamedCurves.getByOID(oid);
dParams = new ECDomainParameters(
ecP.getCurve(),
ecP.getG(),
ecP.getN(),
ecP.getH(),
ecP.getSeed());
}
else
{
X9ECParameters ecP = new X9ECParameters(
(ASN1Sequence)para.getParameters());
dParams = new ECDomainParameters(
ecP.getCurve(),
ecP.getG(),
ecP.getN(),
ecP.getH(),
ecP.getSeed());
}
ECPrivateKeyStructure ec = new ECPrivateKeyStructure((ASN1Sequence)keyInfo.getPrivateKey());
return(new ECPrivateKeyParameters(ec.getKey(), dParams));
}
else
{
throw new Exception("algorithm identifier in key not recognised");
}
}