package org.bouncycastle.mozilla;import java.io.ByteArrayInputStream;import java.security.PublicKey;import java.security.Signature;import java.security.SignatureException;import java.security.NoSuchAlgorithmException;import java.security.KeyFactory;import java.security.InvalidKeyException;import java.security.NoSuchProviderException;import java.security.spec.InvalidKeySpecException;import java.security.spec.X509EncodedKeySpec;import org.bouncycastle.asn1.ASN1Encodable;import org.bouncycastle.asn1.ASN1InputStream;import org.bouncycastle.asn1.DERObject;import org.bouncycastle.asn1.ASN1Sequence;import org.bouncycastle.asn1.DERBitString;import org.bouncycastle.asn1.mozilla.PublicKeyAndChallenge;import org.bouncycastle.asn1.x509.SubjectPublicKeyInfo;import org.bouncycastle.asn1.x509.AlgorithmIdentifier;/** * This is designed to parse the SignedPublicKeyAndChallenge created by the * KEYGEN tag included by Mozilla based browsers. *  <pre> *  PublicKeyAndChallenge ::= SEQUENCE { *    spki SubjectPublicKeyInfo, *    challenge IA5STRING *  } * *  SignedPublicKeyAndChallenge ::= SEQUENCE { *    publicKeyAndChallenge PublicKeyAndChallenge, *    signatureAlgorithm AlgorithmIdentifier, *    signature BIT STRING *  } *  </pre> */public class SignedPublicKeyAndChallenge    extends ASN1Encodable{    private static ASN1Sequence toDERSequence(byte[]  bytes)    {        try        {            ByteArrayInputStream    bIn = new ByteArrayInputStream(bytes);            ASN1InputStream         aIn = new ASN1InputStream(bIn);            return (ASN1Sequence)aIn.readObject();        }        catch (Exception e)        {            throw new IllegalArgumentException("badly encoded request");        }    }    private ASN1Sequence          spkacSeq;    private PublicKeyAndChallenge pkac;    private AlgorithmIdentifier   signatureAlgorithm;    private DERBitString          signature;    public SignedPublicKeyAndChallenge(byte[] bytes)    {        spkacSeq = toDERSequence(bytes);        pkac = PublicKeyAndChallenge.getInstance(spkacSeq.getObjectAt(0));        signatureAlgorithm =             AlgorithmIdentifier.getInstance(spkacSeq.getObjectAt(1));        signature = (DERBitString)spkacSeq.getObjectAt(2);    }    public DERObject toASN1Object()    {        return spkacSeq;    }    public PublicKeyAndChallenge getPublicKeyAndChallenge()    {        return pkac;    }    public boolean verify(String provider)        throws NoSuchAlgorithmException, SignatureException,                NoSuchProviderException, InvalidKeyException    {        Signature sig = null;        sig = Signature.getInstance(signatureAlgorithm.getObjectId().getId(),                                    provider);        PublicKey pubKey = this.getPublicKey(provider);        sig.initVerify(pubKey);        DERBitString pkBytes = new DERBitString(pkac);        sig.update(pkBytes.getBytes());        return sig.verify(signature.getBytes());    }    public PublicKey getPublicKey(String provider)        throws NoSuchAlgorithmException, NoSuchProviderException,                InvalidKeyException    {        SubjectPublicKeyInfo subjectPKInfo = pkac.getSubjectPublicKeyInfo();        try        {            DERBitString bStr = new DERBitString(subjectPKInfo);            X509EncodedKeySpec xspec = new X509EncodedKeySpec(bStr.getBytes());                        AlgorithmIdentifier keyAlg = subjectPKInfo.getAlgorithmId ();            KeyFactory factory =                KeyFactory.getInstance(keyAlg.getObjectId().getId(),provider);            return factory.generatePublic(xspec);                                   }        catch (InvalidKeySpecException e)        {            throw new InvalidKeyException("error encoding public key");        }    }}