package org.bouncycastle.pqc.jcajce.provider.mceliece;
import java.io.IOException;
import java.security.InvalidKeyException;
import java.security.Key;
import java.security.KeyFactorySpi;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.KeySpec;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import org.bouncycastle.asn1.ASN1Primitive;
import org.bouncycastle.asn1.pkcs.PrivateKeyInfo;
import org.bouncycastle.asn1.x509.AlgorithmIdentifier;
import org.bouncycastle.asn1.x509.SubjectPublicKeyInfo;
import org.bouncycastle.crypto.Digest;
import org.bouncycastle.crypto.digests.SHA256Digest;
import org.bouncycastle.pqc.asn1.McEliecePrivateKey;
import org.bouncycastle.pqc.asn1.McEliecePublicKey;
import org.bouncycastle.pqc.asn1.PQCObjectIdentifiers;
import org.bouncycastle.pqc.crypto.mceliece.McEliecePrivateKeyParameters;
import org.bouncycastle.pqc.crypto.mceliece.McEliecePublicKeyParameters;
/**
* This class is used to translate between McEliece keys and key specifications.
*
* @see BCMcEliecePrivateKey
* @see BCMcEliecePublicKey
*/
public class McElieceKeyFactorySpi
extends KeyFactorySpi
{
/**
* The OID of the algorithm.
*/
public static final String OID = "1.3.6.1.4.1.8301.3.1.3.4.1";
/**
* Converts, if possible, a key specification into a
* {@link BCMcEliecePublicKey}. {@link X509EncodedKeySpec}.
*
* @param keySpec the key specification
* @return the McEliece public key
* @throws InvalidKeySpecException if the key specification is not supported.
*/
protected PublicKey engineGeneratePublic(KeySpec keySpec)
throws InvalidKeySpecException
{
if (keySpec instanceof X509EncodedKeySpec)
{
// get the DER-encoded Key according to X.509 from the spec
byte[] encKey = ((X509EncodedKeySpec)keySpec).getEncoded();
// decode the SubjectPublicKeyInfo data structure to the pki object
SubjectPublicKeyInfo pki;
try
{
pki = SubjectPublicKeyInfo.getInstance(ASN1Primitive.fromByteArray(encKey));
}
catch (IOException e)
{
throw new InvalidKeySpecException(e.toString());
}
try
{
if (PQCObjectIdentifiers.mcEliece.equals(pki.getAlgorithm().getAlgorithm()))
{
McEliecePublicKey key = McEliecePublicKey.getInstance(pki.parsePublicKey());
return new BCMcEliecePublicKey(new McEliecePublicKeyParameters(key.getN(), key.getT(), key.getG()));
}
else
{
throw new InvalidKeySpecException("Unable to recognise OID in McEliece public key");
}
}
catch (IOException cce)
{
throw new InvalidKeySpecException(
"Unable to decode X509EncodedKeySpec: "
+ cce.getMessage());
}
}
throw new InvalidKeySpecException("Unsupported key specification: "
+ keySpec.getClass() + ".");
}
/**
* Converts, if possible, a key specification into a
* {@link BCMcEliecePrivateKey}.
*
* @param keySpec the key specification
* @return the McEliece private key
* @throws InvalidKeySpecException if the KeySpec is not supported.
*/
protected PrivateKey engineGeneratePrivate(KeySpec keySpec)
throws InvalidKeySpecException
{
if (keySpec instanceof PKCS8EncodedKeySpec)
{
// get the DER-encoded Key according to PKCS#8 from the spec
byte[] encKey = ((PKCS8EncodedKeySpec)keySpec).getEncoded();
// decode the PKCS#8 data structure to the pki object
PrivateKeyInfo pki;
try
{
pki = PrivateKeyInfo.getInstance(ASN1Primitive.fromByteArray(encKey));
}
catch (IOException e)
{
throw new InvalidKeySpecException("Unable to decode PKCS8EncodedKeySpec: " + e);
}
try
{
if (PQCObjectIdentifiers.mcEliece.equals(pki.getPrivateKeyAlgorithm().getAlgorithm()))
{
McEliecePrivateKey key = McEliecePrivateKey.getInstance(pki.parsePrivateKey());
return new BCMcEliecePrivateKey(new McEliecePrivateKeyParameters(key.getN(), key.getK(), key.getField(), key.getGoppaPoly(), key.getP1(), key.getP2(), key.getSInv()));
}
else
{
throw new InvalidKeySpecException("Unable to recognise OID in McEliece private key");
}
}
catch (IOException cce)
{
throw new InvalidKeySpecException(
"Unable to decode PKCS8EncodedKeySpec.");
}
}
throw new InvalidKeySpecException("Unsupported key specification: "
+ keySpec.getClass() + ".");
}
/**
* Converts, if possible, a given key into a key specification. Currently,
* the following key specifications are supported:
*
* @param key the key
* @param keySpec the key specification
* @return the specification of the McEliece key
* @throws InvalidKeySpecException if the key type or the key specification is not
* supported.
* @see BCMcEliecePrivateKey
* @see BCMcEliecePublicKey
*/
public KeySpec getKeySpec(Key key, Class keySpec)
throws InvalidKeySpecException
{
if (key instanceof BCMcEliecePrivateKey)
{
if (PKCS8EncodedKeySpec.class.isAssignableFrom(keySpec))
{
return new PKCS8EncodedKeySpec(key.getEncoded());
}
}
else if (key instanceof BCMcEliecePublicKey)
{
if (X509EncodedKeySpec.class.isAssignableFrom(keySpec))
{
return new X509EncodedKeySpec(key.getEncoded());
}
}
else
{
throw new InvalidKeySpecException("Unsupported key type: "
+ key.getClass() + ".");
}
throw new InvalidKeySpecException("Unknown key specification: "
+ keySpec + ".");
}
/**
* Translates a key into a form known by the FlexiProvider. Currently, only
* the following "source" keys are supported: {@link BCMcEliecePrivateKey},
* {@link BCMcEliecePublicKey}.
*
* @param key the key
* @return a key of a known key type
* @throws InvalidKeyException if the key type is not supported.
*/
public Key translateKey(Key key)
throws InvalidKeyException
{
if ((key instanceof BCMcEliecePrivateKey)
|| (key instanceof BCMcEliecePublicKey))
{
return key;
}
throw new InvalidKeyException("Unsupported key type.");
}
public PublicKey generatePublic(SubjectPublicKeyInfo pki)
throws InvalidKeySpecException
{
// get the inner type inside the BIT STRING
try
{
ASN1Primitive innerType = pki.parsePublicKey();
McEliecePublicKey key = McEliecePublicKey.getInstance(innerType);
return new BCMcEliecePublicKey(new McEliecePublicKeyParameters(key.getN(), key.getT(), key.getG()));
}
catch (IOException cce)
{
throw new InvalidKeySpecException("Unable to decode X509EncodedKeySpec");
}
}
public PrivateKey generatePrivate(PrivateKeyInfo pki)
throws InvalidKeySpecException
{
// get the inner type inside the BIT STRING
try
{
ASN1Primitive innerType = pki.parsePrivateKey().toASN1Primitive();
McEliecePrivateKey key = McEliecePrivateKey.getInstance(innerType);
return new BCMcEliecePrivateKey(new McEliecePrivateKeyParameters(key.getN(), key.getK(), key.getField(), key.getGoppaPoly(), key.getP1(), key.getP2(), key.getSInv()));
}
catch (IOException cce)
{
throw new InvalidKeySpecException("Unable to decode PKCS8EncodedKeySpec");
}
}
protected KeySpec engineGetKeySpec(Key key, Class tClass)
throws InvalidKeySpecException
{
return null; //To change body of implemented methods use File | Settings | File Templates.
}
protected Key engineTranslateKey(Key key)
throws InvalidKeyException
{
return null; //To change body of implemented methods use File | Settings | File Templates.
}
private static Digest getDigest(AlgorithmIdentifier algId)
{
return new SHA256Digest();
}
}