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package sun.security.pkcs11;

import java.io.IOException;

import java.math.BigInteger;

import java.security.*;

import java.security.interfaces.*;

import java.security.spec.*;

import sun.security.ec.ECPublicKeyImpl;

import sun.security.ec.ECParameters;

import sun.security.ec.NamedCurve;

import static sun.security.pkcs11.TemplateManager.*;

import sun.security.pkcs11.wrapper.*;

import static sun.security.pkcs11.wrapper.PKCS11Constants.*;

import sun.security.util.DerValue;

/**

 * EC KeyFactory implemenation.

 *

 * @author  Andreas Sterbenz

 * @since   1.6

 */

final class P11ECKeyFactory extends P11KeyFactory {

    P11ECKeyFactory(Token token, String algorithm) {

        super(token, algorithm);

    }

    static ECParameterSpec getECParameterSpec(String name) {

        return NamedCurve.getECParameterSpec(name);

    }

    static ECParameterSpec getECParameterSpec(int keySize) {

        return NamedCurve.getECParameterSpec(keySize);

    }

    // Check that spec is a known supported curve and convert it to our

    // ECParameterSpec subclass. If not possible, return null.

    static ECParameterSpec getECParameterSpec(ECParameterSpec spec) {

        return ECParameters.getNamedCurve(spec);

    }

    static ECParameterSpec decodeParameters(byte[] params) throws IOException {

        return ECParameters.decodeParameters(params);

    }

    static byte[] encodeParameters(ECParameterSpec params) {

        return ECParameters.encodeParameters(params);

    }

    static ECPoint decodePoint(byte[] encoded, EllipticCurve curve) throws IOException {

        return ECParameters.decodePoint(encoded, curve);

    }

    // Used by ECDH KeyAgreement

    static byte[] getEncodedPublicValue(PublicKey key) throws InvalidKeyException {

        if (key instanceof ECPublicKeyImpl) {

            return ((ECPublicKeyImpl)key).getEncodedPublicValue();

        } else if (key instanceof ECPublicKey) {

            ECPublicKey ecKey = (ECPublicKey)key;

            ECPoint w = ecKey.getW();

            ECParameterSpec params = ecKey.getParams();

            return ECParameters.encodePoint(w, params.getCurve());

        } else {

            // should never occur

            throw new InvalidKeyException

                ("Key class not yet supported: " + key.getClass().getName());

        }

    }

    PublicKey implTranslatePublicKey(PublicKey key) throws InvalidKeyException {

        try {

            if (key instanceof ECPublicKey) {

                ECPublicKey ecKey = (ECPublicKey)key;

                return generatePublic(

                    ecKey.getW(),

                    ecKey.getParams()

                );

            } else if ("X.509".equals(key.getFormat())) {

                // let Sun provider parse for us, then recurse

                byte[] encoded = key.getEncoded();

                key = new sun.security.ec.ECPublicKeyImpl(encoded);

                return implTranslatePublicKey(key);

            } else {

                throw new InvalidKeyException("PublicKey must be instance "

                        + "of ECPublicKey or have X.509 encoding");

            }

        } catch (PKCS11Exception e) {

            throw new InvalidKeyException("Could not create EC public key", e);

        }

    }

    PrivateKey implTranslatePrivateKey(PrivateKey key)

            throws InvalidKeyException {

        try {

            if (key instanceof ECPrivateKey) {

                ECPrivateKey ecKey = (ECPrivateKey)key;

                return generatePrivate(

                    ecKey.getS(),

                    ecKey.getParams()

                );

            } else if ("PKCS#8".equals(key.getFormat())) {

                // let Sun provider parse for us, then recurse

                byte[] encoded = key.getEncoded();

                key = new sun.security.ec.ECPrivateKeyImpl(encoded);

                return implTranslatePrivateKey(key);

            } else {

                throw new InvalidKeyException("PrivateKey must be instance "

                        + "of ECPrivateKey or have PKCS#8 encoding");

            }

        } catch (PKCS11Exception e) {

            throw new InvalidKeyException("Could not create EC private key", e);

        }

    }

    // see JCA spec

    protected PublicKey engineGeneratePublic(KeySpec keySpec)

            throws InvalidKeySpecException {

        token.ensureValid();

        if (keySpec instanceof X509EncodedKeySpec) {

            try {

                byte[] encoded = ((X509EncodedKeySpec)keySpec).getEncoded();

                PublicKey key = new sun.security.ec.ECPublicKeyImpl(encoded);

                return implTranslatePublicKey(key);

            } catch (InvalidKeyException e) {

                throw new InvalidKeySpecException

                        ("Could not create EC public key", e);

            }

        }

        if (keySpec instanceof ECPublicKeySpec == false) {

            throw new InvalidKeySpecException("Only ECPublicKeySpec and "

                + "X509EncodedKeySpec supported for EC public keys");

        }

        try {

            ECPublicKeySpec ec = (ECPublicKeySpec)keySpec;

            return generatePublic(

                ec.getW(),

                ec.getParams()

            );

        } catch (PKCS11Exception e) {

            throw new InvalidKeySpecException

                ("Could not create EC public key", e);

        }

    }

    // see JCA spec

    protected PrivateKey engineGeneratePrivate(KeySpec keySpec)

            throws InvalidKeySpecException {

        token.ensureValid();

        if (keySpec instanceof PKCS8EncodedKeySpec) {

            try {

                byte[] encoded = ((PKCS8EncodedKeySpec)keySpec).getEncoded();

                PrivateKey key = new sun.security.ec.ECPrivateKeyImpl(encoded);

                return implTranslatePrivateKey(key);

            } catch (GeneralSecurityException e) {

                throw new InvalidKeySpecException

                        ("Could not create EC private key", e);

            }

        }

        if (keySpec instanceof ECPrivateKeySpec == false) {

            throw new InvalidKeySpecException("Only ECPrivateKeySpec and "

                + "PKCS8EncodedKeySpec supported for EC private keys");

        }

        try {

            ECPrivateKeySpec ec = (ECPrivateKeySpec)keySpec;

            return generatePrivate(

                ec.getS(),

                ec.getParams()

            );

        } catch (PKCS11Exception e) {

            throw new InvalidKeySpecException

                ("Could not create EC private key", e);

        }

    }

    private PublicKey generatePublic(ECPoint point, ECParameterSpec params) throws PKCS11Exception {

        byte[] encodedParams = ECParameters.encodeParameters(params);

        byte[] encodedPoint = null;

        DerValue pkECPoint = new DerValue(DerValue.tag_OctetString,

            ECParameters.encodePoint(point, params.getCurve()));

        try {

            encodedPoint = pkECPoint.toByteArray();

        } catch (IOException e) {

            throw new IllegalArgumentException("Could not DER encode point", e);

        }

        CK_ATTRIBUTE[] attributes = new CK_ATTRIBUTE[] {

            new CK_ATTRIBUTE(CKA_CLASS, CKO_PUBLIC_KEY),

            new CK_ATTRIBUTE(CKA_KEY_TYPE, CKK_EC),

            new CK_ATTRIBUTE(CKA_EC_POINT, encodedPoint),

            new CK_ATTRIBUTE(CKA_EC_PARAMS, encodedParams),

        };

        attributes = token.getAttributes

                (O_IMPORT, CKO_PUBLIC_KEY, CKK_EC, attributes);

        Session session = null;

        try {

            session = token.getObjSession();

            long keyID = token.p11.C_CreateObject(session.id(), attributes);

            return P11Key.publicKey

                (session, keyID, "EC", params.getCurve().getField().getFieldSize(), attributes);

        } finally {

            token.releaseSession(session);

        }

    }

    private PrivateKey generatePrivate(BigInteger s, ECParameterSpec params) throws PKCS11Exception {

        byte[] encodedParams = ECParameters.encodeParameters(params);

        CK_ATTRIBUTE[] attributes = new CK_ATTRIBUTE[] {

            new CK_ATTRIBUTE(CKA_CLASS, CKO_PRIVATE_KEY),

            new CK_ATTRIBUTE(CKA_KEY_TYPE, CKK_EC),

            new CK_ATTRIBUTE(CKA_VALUE, s),

            new CK_ATTRIBUTE(CKA_EC_PARAMS, encodedParams),

        };

        attributes = token.getAttributes

                (O_IMPORT, CKO_PRIVATE_KEY, CKK_EC, attributes);

        Session session = null;

        try {

            session = token.getObjSession();

            long keyID = token.p11.C_CreateObject(session.id(), attributes);

            return P11Key.privateKey

                (session, keyID, "EC", params.getCurve().getField().getFieldSize(), attributes);

        } finally {

            token.releaseSession(session);

        }

    }

    KeySpec implGetPublicKeySpec(P11Key key, Class keySpec, Session[] session)

            throws PKCS11Exception, InvalidKeySpecException {

        if (ECPublicKeySpec.class.isAssignableFrom(keySpec)) {

            session[0] = token.getObjSession();

            CK_ATTRIBUTE[] attributes = new CK_ATTRIBUTE[] {

                new CK_ATTRIBUTE(CKA_EC_POINT),

                new CK_ATTRIBUTE(CKA_EC_PARAMS),

            };

            token.p11.C_GetAttributeValue(session[0].id(), key.keyID, attributes);

            try {

                ECParameterSpec params = decodeParameters(attributes[1].getByteArray());

                ECPoint point = decodePoint(attributes[0].getByteArray(), params.getCurve());

                return new ECPublicKeySpec(point, params);

            } catch (IOException e) {

                throw new InvalidKeySpecException("Could not parse key", e);

            }

        } else { // X.509 handled in superclass

            throw new InvalidKeySpecException("Only ECPublicKeySpec and "

                + "X509EncodedKeySpec supported for EC public keys");

        }

    }

    KeySpec implGetPrivateKeySpec(P11Key key, Class keySpec, Session[] session)

            throws PKCS11Exception, InvalidKeySpecException {

        if (ECPrivateKeySpec.class.isAssignableFrom(keySpec)) {

            session[0] = token.getObjSession();

            CK_ATTRIBUTE[] attributes = new CK_ATTRIBUTE[] {

                new CK_ATTRIBUTE(CKA_VALUE),

                new CK_ATTRIBUTE(CKA_EC_PARAMS),

            };

            token.p11.C_GetAttributeValue(session[0].id(), key.keyID, attributes);

            try {

                ECParameterSpec params = decodeParameters(attributes[1].getByteArray());

                return new ECPrivateKeySpec(attributes[0].getBigInteger(), params);

            } catch (IOException e) {

                throw new InvalidKeySpecException("Could not parse key", e);

            }

        } else { // PKCS#8 handled in superclass

            throw new InvalidKeySpecException("Only ECPrivateKeySpec "

                + "and PKCS8EncodedKeySpec supported for EC private keys");

        }

    }

    KeyFactory implGetSoftwareFactory() throws GeneralSecurityException {

        return sun.security.ec.ECKeyFactory.INSTANCE;

    }

}