Example usage for org.bouncycastle.asn1.x9 X9ECParameters toASN1Primitive

Introduction

In this page you can find the example usage for org.bouncycastle.asn1.x9 X9ECParameters toASN1Primitive.

Prototype

public ASN1Primitive toASN1Primitive() 

Source Link

Document

Produce an object suitable for an ASN1OutputStream.

Usage

From source file:org.jmrtd.Util.java

License:Open Source License

public static SubjectPublicKeyInfo toSubjectPublicKeyInfo(PublicKey publicKey) {
    try {//ww  w  .ja  v  a2s .co m
        String algorithm = publicKey.getAlgorithm();
        if ("EC".equals(algorithm) || "ECDH".equals(algorithm) || (publicKey instanceof ECPublicKey)) {
            ASN1InputStream asn1In = new ASN1InputStream(publicKey.getEncoded());
            SubjectPublicKeyInfo subjectPublicKeyInfo = new SubjectPublicKeyInfo(
                    (ASN1Sequence) asn1In.readObject());
            asn1In.close();
            AlgorithmIdentifier algorithmIdentifier = subjectPublicKeyInfo.getAlgorithm();
            String algOID = algorithmIdentifier.getAlgorithm().getId();
            if (!SecurityInfo.ID_EC_PUBLIC_KEY.equals(algOID)) {
                throw new IllegalStateException("Was expecting id-ecPublicKey ("
                        + SecurityInfo.ID_EC_PUBLIC_KEY_TYPE + "), found " + algOID);
            }
            ASN1Primitive derEncodedParams = algorithmIdentifier.getParameters().toASN1Primitive();
            X9ECParameters params = null;
            if (derEncodedParams instanceof ASN1ObjectIdentifier) {
                ASN1ObjectIdentifier paramsOID = (ASN1ObjectIdentifier) derEncodedParams;

                /* It's a named curve from X9.62. */
                params = X962NamedCurves.getByOID(paramsOID);
                if (params == null) {
                    throw new IllegalStateException(
                            "Could not find X9.62 named curve for OID " + paramsOID.getId());
                }

                /* Reconstruct the parameters. */
                org.bouncycastle.math.ec.ECPoint generator = params.getG();
                org.bouncycastle.math.ec.ECCurve curve = generator.getCurve();
                generator = curve.createPoint(generator.getX().toBigInteger(), generator.getY().toBigInteger(),
                        false);
                params = new X9ECParameters(params.getCurve(), generator, params.getN(), params.getH(),
                        params.getSeed());
            } else {
                /* It's not a named curve, we can just return the decoded public key info. */
                return subjectPublicKeyInfo;
            }

            if (publicKey instanceof org.bouncycastle.jce.interfaces.ECPublicKey) {
                org.bouncycastle.jce.interfaces.ECPublicKey ecPublicKey = (org.bouncycastle.jce.interfaces.ECPublicKey) publicKey;
                AlgorithmIdentifier id = new AlgorithmIdentifier(
                        subjectPublicKeyInfo.getAlgorithm().getAlgorithm(), params.toASN1Primitive());
                org.bouncycastle.math.ec.ECPoint q = ecPublicKey.getQ();
                /* FIXME: investigate the compressed versus uncompressed point issue. What is allowed in TR03110? -- MO */
                // In case we would like to compress the point:
                // p = p.getCurve().createPoint(p.getX().toBigInteger(), p.getY().toBigInteger(), true);
                subjectPublicKeyInfo = new SubjectPublicKeyInfo(id, q.getEncoded());
                return subjectPublicKeyInfo;
            } else {
                return subjectPublicKeyInfo;
            }
        } else if ("DH".equals(algorithm) || (publicKey instanceof DHPublicKey)) {
            DHPublicKey dhPublicKey = (DHPublicKey) publicKey;
            DHParameterSpec dhSpec = dhPublicKey.getParams();
            return new SubjectPublicKeyInfo(
                    new AlgorithmIdentifier(EACObjectIdentifiers.id_PK_DH,
                            new DHParameter(dhSpec.getP(), dhSpec.getG(), dhSpec.getL()).toASN1Primitive()),
                    new ASN1Integer(dhPublicKey.getY()));
        } else {
            throw new IllegalArgumentException(
                    "Unrecognized key type, found " + publicKey.getAlgorithm() + ", should be DH or ECDH");
        }
    } catch (Exception e) {
        LOGGER.severe("Exception: " + e.getMessage());
        return null;
    }
}

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