// 
// Decompiled by Procyon v0.6.0
// 

package org.bouncycastle.pqc.jcajce.provider.falcon;

import java.security.spec.AlgorithmParameterSpec;
import java.security.SignatureException;
import org.bouncycastle.pqc.crypto.falcon.FalconPrivateKeyParameters;
import org.bouncycastle.crypto.params.ParametersWithRandom;
import java.security.PrivateKey;
import org.bouncycastle.crypto.CipherParameters;
import java.security.InvalidKeyException;
import org.bouncycastle.asn1.x509.SubjectPublicKeyInfo;
import java.security.PublicKey;
import org.bouncycastle.util.Strings;
import org.bouncycastle.pqc.crypto.falcon.FalconParameters;
import java.security.SecureRandom;
import org.bouncycastle.pqc.crypto.falcon.FalconSigner;
import java.io.ByteArrayOutputStream;
import java.security.Signature;

public class SignatureSpi extends Signature
{
    private ByteArrayOutputStream bOut;
    private FalconSigner signer;
    private SecureRandom random;
    private FalconParameters parameters;
    
    protected SignatureSpi(final FalconSigner signer) {
        super("FALCON");
        this.bOut = new ByteArrayOutputStream();
        this.signer = signer;
        this.parameters = null;
    }
    
    protected SignatureSpi(final FalconSigner signer, final FalconParameters parameters) {
        super(Strings.toUpperCase(parameters.getName()));
        this.parameters = parameters;
        this.bOut = new ByteArrayOutputStream();
        this.signer = signer;
    }
    
    @Override
    protected void engineInitVerify(PublicKey publicKey) throws InvalidKeyException {
        if (!(publicKey instanceof BCFalconPublicKey)) {
            try {
                publicKey = new BCFalconPublicKey(SubjectPublicKeyInfo.getInstance(publicKey.getEncoded()));
            }
            catch (final Exception cause) {
                throw new InvalidKeyException("unknown public key passed to Falcon: " + cause.getMessage(), cause);
            }
        }
        final BCFalconPublicKey bcFalconPublicKey = (BCFalconPublicKey)publicKey;
        if (this.parameters != null) {
            final String upperCase = Strings.toUpperCase(this.parameters.getName());
            if (!upperCase.equals(bcFalconPublicKey.getAlgorithm())) {
                throw new InvalidKeyException("signature configured for " + upperCase);
            }
        }
        this.signer.init(false, bcFalconPublicKey.getKeyParams());
    }
    
    @Override
    protected void engineInitSign(final PrivateKey privateKey, final SecureRandom random) throws InvalidKeyException {
        this.random = random;
        this.engineInitSign(privateKey);
    }
    
    @Override
    protected void engineInitSign(final PrivateKey privateKey) throws InvalidKeyException {
        if (privateKey instanceof BCFalconPrivateKey) {
            final BCFalconPrivateKey bcFalconPrivateKey = (BCFalconPrivateKey)privateKey;
            final FalconPrivateKeyParameters keyParams = bcFalconPrivateKey.getKeyParams();
            if (this.parameters != null) {
                final String upperCase = Strings.toUpperCase(this.parameters.getName());
                if (!upperCase.equals(bcFalconPrivateKey.getAlgorithm())) {
                    throw new InvalidKeyException("signature configured for " + upperCase);
                }
            }
            if (this.random != null) {
                this.signer.init(true, new ParametersWithRandom(keyParams, this.random));
            }
            else {
                this.signer.init(true, keyParams);
            }
            return;
        }
        throw new InvalidKeyException("unknown private key passed to Falcon");
    }
    
    @Override
    protected void engineUpdate(final byte b) throws SignatureException {
        this.bOut.write(b);
    }
    
    @Override
    protected void engineUpdate(final byte[] b, final int off, final int len) throws SignatureException {
        this.bOut.write(b, off, len);
    }
    
    @Override
    protected byte[] engineSign() throws SignatureException {
        try {
            final byte[] byteArray = this.bOut.toByteArray();
            this.bOut.reset();
            return this.signer.generateSignature(byteArray);
        }
        catch (final Exception ex) {
            throw new SignatureException(ex.toString());
        }
    }
    
    @Override
    protected boolean engineVerify(final byte[] array) throws SignatureException {
        final byte[] byteArray = this.bOut.toByteArray();
        this.bOut.reset();
        return this.signer.verifySignature(byteArray, array);
    }
    
    @Override
    protected void engineSetParameter(final AlgorithmParameterSpec algorithmParameterSpec) {
        throw new UnsupportedOperationException("engineSetParameter unsupported");
    }
    
    @Override
    @Deprecated
    protected void engineSetParameter(final String s, final Object o) {
        throw new UnsupportedOperationException("engineSetParameter unsupported");
    }
    
    @Override
    @Deprecated
    protected Object engineGetParameter(final String s) {
        throw new UnsupportedOperationException("engineSetParameter unsupported");
    }
    
    public static class Base extends SignatureSpi
    {
        public Base() {
            super(new FalconSigner());
        }
    }
    
    public static class Falcon1024 extends SignatureSpi
    {
        public Falcon1024() {
            super(new FalconSigner(), FalconParameters.falcon_1024);
        }
    }
    
    public static class Falcon512 extends SignatureSpi
    {
        public Falcon512() {
            super(new FalconSigner(), FalconParameters.falcon_512);
        }
    }
}