org.spongycastle.jcajce.provider.asymmetric.ec.GMSignatureSpi Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of prov Show documentation

Spongy Castle is a package-rename (org.bouncycastle.* to org.spongycastle.*) of Bouncy Castle intended for the Android platform. Android unfortunately ships with a stripped-down version of Bouncy Castle, which prevents easy upgrades - Spongy Castle overcomes this and provides a full, up-to-date version of the Bouncy Castle cryptographic libs.

The newest version!

package org.spongycastle.jcajce.provider.asymmetric.ec;

import java.io.IOException;
import java.math.BigInteger;
import java.security.InvalidKeyException;
import java.security.PrivateKey;
import java.security.PublicKey;

import org.spongycastle.asn1.ASN1EncodableVector;
import org.spongycastle.asn1.ASN1Encoding;
import org.spongycastle.asn1.ASN1Integer;
import org.spongycastle.asn1.ASN1Primitive;
import org.spongycastle.asn1.ASN1Sequence;
import org.spongycastle.asn1.DERSequence;
import org.spongycastle.crypto.CipherParameters;
import org.spongycastle.crypto.DSA;
import org.spongycastle.crypto.Digest;
import org.spongycastle.crypto.digests.SM3Digest;
import org.spongycastle.crypto.params.ParametersWithRandom;
import org.spongycastle.crypto.signers.SM2Signer;
import org.spongycastle.jcajce.provider.asymmetric.util.DSABase;
import org.spongycastle.jcajce.provider.asymmetric.util.DSAEncoder;
import org.spongycastle.jcajce.provider.asymmetric.util.ECUtil;
import org.spongycastle.util.Arrays;

public class GMSignatureSpi
    extends DSABase
{
    GMSignatureSpi(Digest digest, DSA signer, DSAEncoder encoder)
    {
        super(digest, signer, encoder);
    }

    protected void engineInitVerify(PublicKey publicKey)
        throws InvalidKeyException
    {
        CipherParameters param = ECUtils.generatePublicKeyParameter(publicKey);

        digest.reset();
        signer.init(false, param);
    }

    protected void engineInitSign(
        PrivateKey privateKey)
        throws InvalidKeyException
    {
        CipherParameters param = ECUtil.generatePrivateKeyParameter(privateKey);

        digest.reset();

        if (appRandom != null)
        {
            signer.init(true, new ParametersWithRandom(param, appRandom));
        }
        else
        {
            signer.init(true, param);
        }
    }

    static public class sm3WithSM2
        extends GMSignatureSpi
    {
        public sm3WithSM2()
        {
            super(new SM3Digest(), new SM2Signer(), new StdDSAEncoder());
        }
    }
    
    private static class StdDSAEncoder
        implements DSAEncoder
    {
        public byte[] encode(
            BigInteger r,
            BigInteger s)
            throws IOException
        {
            ASN1EncodableVector v = new ASN1EncodableVector();

            v.add(new ASN1Integer(r));
            v.add(new ASN1Integer(s));

            return new DERSequence(v).getEncoded(ASN1Encoding.DER);
        }

        public BigInteger[] decode(
            byte[] encoding)
            throws IOException
        {
            ASN1Sequence s = (ASN1Sequence)ASN1Primitive.fromByteArray(encoding);
            if (s.size() != 2)
            {
                throw new IOException("malformed signature");
            }
            if (!Arrays.areEqual(encoding, s.getEncoded(ASN1Encoding.DER)))
            {
                throw new IOException("malformed signature");
            }

            BigInteger[] sig = new BigInteger[2];


            sig[0] = ASN1Integer.getInstance(s.getObjectAt(0)).getValue();
            sig[1] = ASN1Integer.getInstance(s.getObjectAt(1)).getValue();

            return sig;
        }
    }
}