package org.bouncycastle.crypto.util;
import org.bouncycastle.asn1.ASN1InputStream;
import org.bouncycastle.asn1.ASN1Object;
import org.bouncycastle.asn1.ASN1OctetString;
import org.bouncycastle.asn1.ASN1Sequence;
import org.bouncycastle.asn1.DERBitString;
import org.bouncycastle.asn1.DERInteger;
import org.bouncycastle.asn1.DERObject;
import org.bouncycastle.asn1.DERObjectIdentifier;
import org.bouncycastle.asn1.DEROctetString;
import org.bouncycastle.asn1.nist.NISTNamedCurves;
import org.bouncycastle.asn1.oiw.ElGamalParameter;
import org.bouncycastle.asn1.oiw.OIWObjectIdentifiers;
import org.bouncycastle.asn1.pkcs.DHParameter;
import org.bouncycastle.asn1.pkcs.PKCSObjectIdentifiers;
import org.bouncycastle.asn1.sec.SECNamedCurves;
import org.bouncycastle.asn1.teletrust.TeleTrusTNamedCurves;
import org.bouncycastle.asn1.x509.AlgorithmIdentifier;
import org.bouncycastle.asn1.x509.DSAParameter;
import org.bouncycastle.asn1.x509.RSAPublicKeyStructure;
import org.bouncycastle.asn1.x509.SubjectPublicKeyInfo;
import org.bouncycastle.asn1.x509.X509ObjectIdentifiers;
import org.bouncycastle.asn1.x9.X962NamedCurves;
import org.bouncycastle.asn1.x9.X962Parameters;
import org.bouncycastle.asn1.x9.X9ECParameters;
import org.bouncycastle.asn1.x9.X9ECPoint;
import org.bouncycastle.asn1.x9.X9ObjectIdentifiers;
import org.bouncycastle.crypto.params.AsymmetricKeyParameter;
import org.bouncycastle.crypto.params.DHParameters;
import org.bouncycastle.crypto.params.DHPublicKeyParameters;
import org.bouncycastle.crypto.params.DSAParameters;
import org.bouncycastle.crypto.params.DSAPublicKeyParameters;
import org.bouncycastle.crypto.params.ECDomainParameters;
import org.bouncycastle.crypto.params.ECPublicKeyParameters;
import org.bouncycastle.crypto.params.ElGamalParameters;
import org.bouncycastle.crypto.params.ElGamalPublicKeyParameters;
import org.bouncycastle.crypto.params.RSAKeyParameters;
import java.io.IOException;
import java.io.InputStream;
/**
* Factory to create asymmetric public key parameters for asymmetric ciphers
* from range of ASN.1 encoded SubjectPublicKeyInfo objects.
*/
public class PublicKeyFactory
{
/**
* Create a public key from a SubjectPublicKeyInfo encoding
*
* @param keyInfoData the SubjectPublicKeyInfo encoding
* @return the appropriate key parameter
* @throws IOException on an error decoding the key
*/
public static AsymmetricKeyParameter createKey(
byte[] keyInfoData)
throws IOException
{
return createKey(
SubjectPublicKeyInfo.getInstance(
ASN1Object.fromByteArray(keyInfoData)));
}
/**
* Create a public key from a SubjectPublicKeyInfo encoding read from a stream
*
* @param inStr the stream to read the SubjectPublicKeyInfo encoding from
* @return the appropriate key parameter
* @throws IOException on an error decoding the key
*/
public static AsymmetricKeyParameter createKey(
InputStream inStr)
throws IOException
{
return createKey(
SubjectPublicKeyInfo.getInstance(
new ASN1InputStream(inStr).readObject()));
}
/**
* Create a public key from the passed in SubjectPublicKeyInfo
*
* @param keyInfo the SubjectPublicKeyInfo containing the key data
* @return the appropriate key parameter
* @throws IOException on an error decoding the key
*/
public static AsymmetricKeyParameter createKey(
SubjectPublicKeyInfo keyInfo)
throws IOException
{
AlgorithmIdentifier algId = keyInfo.getAlgorithmId();
if (algId.getObjectId().equals(PKCSObjectIdentifiers.rsaEncryption)
|| algId.getObjectId().equals(X509ObjectIdentifiers.id_ea_rsa))
{
RSAPublicKeyStructure pubKey = new RSAPublicKeyStructure((ASN1Sequence)keyInfo.getPublicKey());
return new RSAKeyParameters(false, pubKey.getModulus(), pubKey.getPublicExponent());
}
else if (algId.getObjectId().equals(PKCSObjectIdentifiers.dhKeyAgreement)
|| algId.getObjectId().equals(X9ObjectIdentifiers.dhpublicnumber))
{
DHParameter params = new DHParameter((ASN1Sequence)keyInfo.getAlgorithmId().getParameters());
DERInteger derY = (DERInteger)keyInfo.getPublicKey();
return new DHPublicKeyParameters(derY.getValue(), new DHParameters(params.getP(), params.getG()));
}
else if (algId.getObjectId().equals(OIWObjectIdentifiers.elGamalAlgorithm))
{
ElGamalParameter params = new ElGamalParameter((ASN1Sequence)keyInfo.getAlgorithmId().getParameters());
DERInteger derY = (DERInteger)keyInfo.getPublicKey();
return new ElGamalPublicKeyParameters(derY.getValue(), new ElGamalParameters(params.getP(), params.getG()));
}
else if (algId.getObjectId().equals(X9ObjectIdentifiers.id_dsa)
|| algId.getObjectId().equals(OIWObjectIdentifiers.dsaWithSHA1))
{
DSAParameter params = new DSAParameter((ASN1Sequence)keyInfo.getAlgorithmId().getParameters());
DERInteger derY = (DERInteger)keyInfo.getPublicKey();
return new DSAPublicKeyParameters(derY.getValue(), new DSAParameters(params.getP(), params.getQ(), params.getG()));
}
else if (algId.getObjectId().equals(X9ObjectIdentifiers.id_ecPublicKey))
{
X962Parameters params = new X962Parameters((DERObject)keyInfo.getAlgorithmId().getParameters());
ECDomainParameters dParams = null;
if (params.isNamedCurve())
{
DERObjectIdentifier oid = (DERObjectIdentifier)params.getParameters();
X9ECParameters ecP = X962NamedCurves.getByOID(oid);
if (ecP == null)
{
ecP = SECNamedCurves.getByOID(oid);
if (ecP == null)
{
ecP = NISTNamedCurves.getByOID(oid);
if (ecP == null)
{
ecP = TeleTrusTNamedCurves.getByOID(oid);
}
}
}
dParams = new ECDomainParameters(
ecP.getCurve(),
ecP.getG(),
ecP.getN(),
ecP.getH(),
ecP.getSeed());
}
else
{
X9ECParameters ecP = new X9ECParameters(
(ASN1Sequence)params.getParameters());
dParams = new ECDomainParameters(
ecP.getCurve(),
ecP.getG(),
ecP.getN(),
ecP.getH(),
ecP.getSeed());
}
DERBitString bits = keyInfo.getPublicKeyData();
byte[] data = bits.getBytes();
ASN1OctetString key = new DEROctetString(data);
X9ECPoint derQ = new X9ECPoint(dParams.getCurve(), key);
return new ECPublicKeyParameters(derQ.getPoint(), dParams);
}
else
{
throw new RuntimeException("algorithm identifier in key not recognised");
}
}
}