package won.cryptography.key;

import org.bouncycastle.jce.spec.ECNamedCurveSpec;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import won.cryptography.exception.KeyNotSupportedException;

import java.security.Key;
import java.security.PublicKey;
import java.security.interfaces.ECKey;
import java.security.interfaces.ECPublicKey;
import java.security.spec.ECParameterSpec;

/**
 * User: fsalcher
 * Date: 24.07.2014
 */
public class KeyInformationExtractorBouncyCastle implements KeyInformationExtractor {
    private static final Logger logger = LoggerFactory.getLogger(KeyInformationExtractorBouncyCastle.class);

    public String getAlgorithm(Key key) {
        return key.getAlgorithm();
    }

    public String getCurveID(Key key) throws KeyNotSupportedException {
        if (key instanceof ECKey) {
            ECParameterSpec spec = ((ECKey) key).getParams();

            if (spec instanceof ECNamedCurveSpec) {
                return ((ECNamedCurveSpec) spec).getName();
            } else
                return null;
        } else {
            throw new KeyNotSupportedException("Key is not an elliptic curve key!");
        }
    }

    public String getQX(PublicKey publicKey) throws KeyNotSupportedException {
        if (publicKey instanceof ECPublicKey) {
            return ((ECPublicKey) publicKey).getW().getAffineX().toString(16);
        } else {
            throw new KeyNotSupportedException("Key is not an elliptic curve key!");
        }
    }

    public String getQY(PublicKey publicKey) throws KeyNotSupportedException {
        if (publicKey instanceof ECPublicKey) {
            return ((ECPublicKey) publicKey).getW().getAffineY().toString(16);
        } else {
            throw new KeyNotSupportedException("Key is not an elliptic curve key!");
        }
    }
}