org.bouncycastle.jcajce.provider.asymmetric.ies.AlgorithmParametersSpi Maven / Gradle / Ivy

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The Bouncy Castle Java APIs for CMS, PKCS, EAC, TSP, CMP, CRMF, OCSP, and certificate generation. This jar contains APIs for JDK 1.5 and up. The APIs can be used in conjunction with a JCE/JCA provider such as the one provided with the Bouncy Castle Cryptography APIs.
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package org.bouncycastle.jcajce.provider.asymmetric.ies;

import java.io.IOException;
import java.security.spec.AlgorithmParameterSpec;
import java.security.spec.InvalidParameterSpecException;

import org.bouncycastle.asn1.ASN1EncodableVector;
import org.bouncycastle.asn1.ASN1Encoding;
import org.bouncycastle.asn1.ASN1Integer;
import org.bouncycastle.asn1.ASN1OctetString;
import org.bouncycastle.asn1.ASN1Primitive;
import org.bouncycastle.asn1.ASN1Sequence;
import org.bouncycastle.asn1.ASN1TaggedObject;
import org.bouncycastle.asn1.DEROctetString;
import org.bouncycastle.asn1.DERSequence;
import org.bouncycastle.asn1.DERTaggedObject;
import org.bouncycastle.jce.spec.IESParameterSpec;

public class AlgorithmParametersSpi
    extends java.security.AlgorithmParametersSpi
{
    protected boolean isASN1FormatString(String format)
    {
        return format == null || format.equals("ASN.1");
    }

    protected AlgorithmParameterSpec engineGetParameterSpec(
        Class paramSpec)
        throws InvalidParameterSpecException
    {
        if (paramSpec == null)
        {
            throw new NullPointerException("argument to getParameterSpec must not be null");
        }

        return localEngineGetParameterSpec(paramSpec);
    }

    IESParameterSpec currentSpec;

    /**
     * in the absence of a standard way of doing it this will do for
     * now...
     */
    protected byte[] engineGetEncoded()
    {
        try
        {
            ASN1EncodableVector v = new ASN1EncodableVector();

            if (currentSpec.getDerivationV() != null)
            {
                v.add(new DERTaggedObject(false, 0, new DEROctetString(currentSpec.getDerivationV())));
            }
            if (currentSpec.getEncodingV() != null)
            {
                v.add(new DERTaggedObject(false, 1, new DEROctetString(currentSpec.getEncodingV())));
            }
            v.add(new ASN1Integer(currentSpec.getMacKeySize()));
            if (currentSpec.getNonce() != null)
            {
                ASN1EncodableVector cV = new ASN1EncodableVector();

                cV.add(new ASN1Integer(currentSpec.getCipherKeySize()));
                cV.add(new ASN1Integer(currentSpec.getNonce()));

                v.add(new DERSequence(cV));
            }
            return new DERSequence(v).getEncoded(ASN1Encoding.DER);
        }
        catch (IOException e)
        {
            throw new RuntimeException("Error encoding IESParameters");
        }
    }

    protected byte[] engineGetEncoded(
        String format)
    {
        if (isASN1FormatString(format) || format.equalsIgnoreCase("X.509"))
        {
            return engineGetEncoded();
        }

        return null;
    }

    protected AlgorithmParameterSpec localEngineGetParameterSpec(
        Class paramSpec)
        throws InvalidParameterSpecException
    {
        if (paramSpec == IESParameterSpec.class || paramSpec == AlgorithmParameterSpec.class)
        {
            return currentSpec;
        }

        throw new InvalidParameterSpecException("unknown parameter spec passed to ElGamal parameters object.");
    }

    protected void engineInit(
        AlgorithmParameterSpec paramSpec)
        throws InvalidParameterSpecException
    {
        if (!(paramSpec instanceof IESParameterSpec))
        {
            throw new InvalidParameterSpecException("IESParameterSpec required to initialise a IES algorithm parameters object");
        }

        this.currentSpec = (IESParameterSpec)paramSpec;
    }

    protected void engineInit(
        byte[] params)
        throws IOException
    {
        try
        {
            ASN1Sequence s = (ASN1Sequence)ASN1Primitive.fromByteArray(params);

            if (s.size() == 1)
            {
                this.currentSpec = new IESParameterSpec(null, null, ASN1Integer.getInstance(s.getObjectAt(0)).intValueExact());
            }
            else if (s.size() == 2)
            {
                ASN1TaggedObject tagged = ASN1TaggedObject.getInstance(s.getObjectAt(0));

                if (tagged.getTagNo() == 0)
                {
                    this.currentSpec = new IESParameterSpec(ASN1OctetString.getInstance(tagged, false).getOctets(), null, ASN1Integer.getInstance(s.getObjectAt(1)).intValueExact());
                }
                else
                {
                    this.currentSpec = new IESParameterSpec(null, ASN1OctetString.getInstance(tagged, false).getOctets(), ASN1Integer.getInstance(s.getObjectAt(1)).intValueExact());
                }
            }
            else if (s.size() == 3)
            {
                ASN1TaggedObject tagged1 = ASN1TaggedObject.getInstance(s.getObjectAt(0));
                ASN1TaggedObject tagged2 = ASN1TaggedObject.getInstance(s.getObjectAt(1));

                this.currentSpec = new IESParameterSpec(
                    ASN1OctetString.getInstance(tagged1, false).getOctets(),
                    ASN1OctetString.getInstance(tagged2, false).getOctets(),
                    ASN1Integer.getInstance(s.getObjectAt(2)).intValueExact());
            }
            else if (s.size() == 4)
            {
                ASN1TaggedObject tagged1 = ASN1TaggedObject.getInstance(s.getObjectAt(0));
                ASN1TaggedObject tagged2 = ASN1TaggedObject.getInstance(s.getObjectAt(1));
                ASN1Sequence     cipherDet = ASN1Sequence.getInstance(s.getObjectAt(3));

                this.currentSpec = new IESParameterSpec(
                    ASN1OctetString.getInstance(tagged1, false).getOctets(),
                    ASN1OctetString.getInstance(tagged2, false).getOctets(),
                    ASN1Integer.getInstance(s.getObjectAt(2)).intValueExact(),
                    ASN1Integer.getInstance(cipherDet.getObjectAt(0)).intValueExact(),
                    ASN1OctetString.getInstance(cipherDet.getObjectAt(1)).getOctets());
            }
        }
        catch (ClassCastException e)
        {
            throw new IOException("Not a valid IES Parameter encoding.");
        }
        catch (ArrayIndexOutOfBoundsException e)
        {
            throw new IOException("Not a valid IES Parameter encoding.");
        }
    }

    protected void engineInit(
        byte[] params,
        String format)
        throws IOException
    {
        if (isASN1FormatString(format) || format.equalsIgnoreCase("X.509"))
        {
            engineInit(params);
        }
        else
        {
            throw new IOException("Unknown parameter format " + format);
        }
    }

    protected String engineToString()
    {
        return "IES Parameters";
    }
}