org.bouncycastle.openpgp.operator.jcajce.JcaJcePGPUtil Maven / Gradle / Ivy

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The Bouncy Castle Java APIs for the OpenPGP Protocol. The APIs are designed primarily to be used in conjunction with the BC LTS provider but may also be used with other providers providing cryptographic services.

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package org.bouncycastle.openpgp.operator.jcajce;

import java.io.IOException;
import java.math.BigInteger;
import java.security.GeneralSecurityException;
import java.security.Key;
import java.security.PublicKey;
import java.security.spec.AlgorithmParameterSpec;

import javax.crypto.KeyAgreement;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

import org.bouncycastle.asn1.ASN1ObjectIdentifier;
import org.bouncycastle.asn1.cryptlib.CryptlibObjectIdentifiers;
import org.bouncycastle.asn1.edec.EdECObjectIdentifiers;
import org.bouncycastle.asn1.x9.ECNamedCurveTable;
import org.bouncycastle.asn1.x9.X9ECParameters;
import org.bouncycastle.bcpg.PublicKeyPacket;
import org.bouncycastle.crypto.ec.CustomNamedCurves;
import org.bouncycastle.jcajce.spec.HybridValueParameterSpec;
import org.bouncycastle.jcajce.spec.UserKeyingMaterialSpec;
import org.bouncycastle.math.ec.ECCurve;
import org.bouncycastle.math.ec.ECPoint;
import org.bouncycastle.openpgp.PGPException;
import org.bouncycastle.util.Arrays;
import org.bouncycastle.util.BigIntegers;
import org.bouncycastle.util.Strings;

/**
 * Basic utility class
 */
class JcaJcePGPUtil
{
    public static SecretKey makeSymmetricKey(
        int algorithm,
        byte[] keyBytes)
        throws PGPException
    {
        String algName = org.bouncycastle.openpgp.PGPUtil.getSymmetricCipherName(algorithm);

        if (algName == null)
        {
            throw new PGPException("unknown symmetric algorithm: " + algorithm);
        }

        return new SecretKeySpec(keyBytes, algName);
    }

    static ECPoint decodePoint(
        BigInteger encodedPoint,
        ECCurve curve)
        throws IOException
    {
        return curve.decodePoint(BigIntegers.asUnsignedByteArray(encodedPoint));
    }

    static X9ECParameters getX9Parameters(ASN1ObjectIdentifier curveOID)
    {
        X9ECParameters x9Params = CustomNamedCurves.getByOID(curveOID);

        if (x9Params == null)
        {
            return ECNamedCurveTable.getByOID(curveOID);
        }

        return x9Params;
    }

    static HybridValueParameterSpec getHybridValueParameterSpecWithPrepend(byte[] ephmeralPublicKey, PublicKeyPacket pkp, String algorithmName)
        throws IOException
    {
        return new HybridValueParameterSpec(Arrays.concatenate(ephmeralPublicKey, pkp.getKey().getEncoded()), true, new UserKeyingMaterialSpec(Strings.toByteArray("OpenPGP " + algorithmName)));
    }

    static Key getSecret(OperatorHelper helper, PublicKey cryptoPublicKey, String keyEncryptionOID, String agreementName, AlgorithmParameterSpec ukmSpec, Key privKey)
        throws GeneralSecurityException
    {
        KeyAgreement agreement = helper.createKeyAgreement(agreementName);
        agreement.init(privKey, ukmSpec);
        agreement.doPhase(cryptoPublicKey, true);
        return agreement.generateSecret(keyEncryptionOID);
    }

    static boolean isX25519(ASN1ObjectIdentifier curveID)
    {
        return curveID.equals(CryptlibObjectIdentifiers.curvey25519) || curveID.equals(EdECObjectIdentifiers.id_X25519);
    }
}