Java Code Examples for sun.security.util.DerInputStream#getOctetString()

public static void createPath(String[] certs) throws Exception {

        X509Certificate anchorCert = getCertFromFile(certs[0]);
        byte [] nameConstraints = anchorCert.getExtensionValue("2.5.29.30");
        if (nameConstraints != null) {
            DerInputStream in = new DerInputStream(nameConstraints);
            nameConstraints = in.getOctetString();
        }
        TrustAnchor anchor = new TrustAnchor(anchorCert, nameConstraints);
        List list = new ArrayList();
        for (int i = 1; i < certs.length; i++) {
            list.add(0, getCertFromFile(certs[i]));
        }
        CertificateFactory cf = CertificateFactory.getInstance("X509");
        path = cf.generateCertPath(list);

        anchors = Collections.singleton(anchor);
        params = new PKIXParameters(anchors);
        params.setRevocationEnabled(false);
    }
 

private void testPolicy() throws IOException {
    System.out.println("X.509 Certificate Match on certificatePolicies");
    // test encoding of CertificatePoliciesExtension because we wrote the
    // code
    // bad match
    X509CertSelector selector = new X509CertSelector();
    Set<String> s = new HashSet<>();
    s.add(new String("1.2.5.7.68"));
    selector.setPolicy(s);
    checkMatch(selector, cert, false);

    // good match
    DerInputStream in = new DerInputStream(cert.getExtensionValue("2.5.29.32"));
    CertificatePoliciesExtension ext = new CertificatePoliciesExtension(false, in.getOctetString());
    List<PolicyInformation> policies = ext.get(CertificatePoliciesExtension.POLICIES);
    // match on the first policy id
    PolicyInformation policyInfo = (PolicyInformation) policies.get(0);
    s.clear();
    s.add(policyInfo.getPolicyIdentifier().getIdentifier().toString());
    selector.setPolicy(s);
    checkMatch(selector, cert, true);
}
 

private static X509CertSelector generateSelector(String name)
            throws Exception {
    X509CertSelector selector = new X509CertSelector();

    // generate certificate from certificate string
    CertificateFactory cf = CertificateFactory.getInstance("X.509");
    ByteArrayInputStream is = null;
    if (name.equals("subca")) {
        is = new ByteArrayInputStream(subCaCertStr.getBytes());
    } else if (name.equals("subci")) {
        is = new ByteArrayInputStream(subCrlIssuerCertStr.getBytes());
    } else {
        is = new ByteArrayInputStream(targetCertStr.getBytes());
    }

    X509Certificate target = (X509Certificate)cf.generateCertificate(is);
    byte[] extVal = target.getExtensionValue("2.5.29.14");
    if (extVal != null) {
        DerInputStream in = new DerInputStream(extVal);
        byte[] subjectKID = in.getOctetString();
        selector.setSubjectKeyIdentifier(subjectKID);
    } else {
        // unlikely to happen.
        throw new Exception("unexpected certificate: no SKID extension");
    }

    return selector;
}
 

private boolean matchSubjectKeyID(X509Certificate xcert) {
    if (ski == null) {
        return true;
    }
    try {
        byte[] extVal = xcert.getExtensionValue("2.5.29.14");
        if (extVal == null) {
            if (debug != null) {
                debug.println("AdaptableX509CertSelector.match: "
                    + "no subject key ID extension. Subject: "
                    + xcert.getSubjectX500Principal());
            }
            return true;
        }
        DerInputStream in = new DerInputStream(extVal);
        byte[] certSubjectKeyID = in.getOctetString();
        if (certSubjectKeyID == null ||
                !Arrays.equals(ski, certSubjectKeyID)) {
            if (debug != null) {
                debug.println("AdaptableX509CertSelector.match: "
                    + "subject key IDs don't match. "
                    + "Expected: " + Arrays.toString(ski) + " "
                    + "Cert's: " + Arrays.toString(certSubjectKeyID));
            }
            return false;
        }
    } catch (IOException ex) {
        if (debug != null) {
            debug.println("AdaptableX509CertSelector.match: "
                + "exception in subject key ID check");
        }
        return false;
    }
    return true;
}
 

private static X509CertSelector generateSelector(String name)
            throws Exception {
    X509CertSelector selector = new X509CertSelector();

    // generate certificate from certificate string
    CertificateFactory cf = CertificateFactory.getInstance("X.509");
    ByteArrayInputStream is = null;
    if (name.equals("subca")) {
        is = new ByteArrayInputStream(subCaCertStr.getBytes());
    } else if (name.equals("subci")) {
        is = new ByteArrayInputStream(subCrlIssuerCertStr.getBytes());
    } else {
        is = new ByteArrayInputStream(targetCertStr.getBytes());
    }

    X509Certificate target = (X509Certificate)cf.generateCertificate(is);
    byte[] extVal = target.getExtensionValue("2.5.29.14");
    if (extVal != null) {
        DerInputStream in = new DerInputStream(extVal);
        byte[] subjectKID = in.getOctetString();
        selector.setSubjectKeyIdentifier(subjectKID);
    } else {
        // unlikely to happen.
        throw new Exception("unexpected certificate: no SKID extension");
    }

    return selector;
}
 

private boolean matchSubjectKeyID(X509Certificate xcert) {
    if (ski == null) {
        return true;
    }
    try {
        byte[] extVal = xcert.getExtensionValue("2.5.29.14");
        if (extVal == null) {
            if (debug != null) {
                debug.println("AdaptableX509CertSelector.match: "
                    + "no subject key ID extension. Subject: "
                    + xcert.getSubjectX500Principal());
            }
            return true;
        }
        DerInputStream in = new DerInputStream(extVal);
        byte[] certSubjectKeyID = in.getOctetString();
        if (certSubjectKeyID == null ||
                !Arrays.equals(ski, certSubjectKeyID)) {
            if (debug != null) {
                debug.println("AdaptableX509CertSelector.match: "
                    + "subject key IDs don't match. "
                    + "Expected: " + Arrays.toString(ski) + " "
                    + "Cert's: " + Arrays.toString(certSubjectKeyID));
            }
            return false;
        }
    } catch (IOException ex) {
        if (debug != null) {
            debug.println("AdaptableX509CertSelector.match: "
                + "exception in subject key ID check");
        }
        return false;
    }
    return true;
}
 

private boolean matchSubjectKeyID(X509Certificate xcert) {
    if (subjectKeyID == null) {
        return true;
    }
    try {
        byte[] extVal = xcert.getExtensionValue("2.5.29.14");
        if (extVal == null) {
            if (debug != null) {
                debug.println("X509CertSelector.match: "
                    + "no subject key ID extension");
            }
            return false;
        }
        DerInputStream in = new DerInputStream(extVal);
        byte[] certSubjectKeyID = in.getOctetString();
        if (certSubjectKeyID == null ||
                !Arrays.equals(subjectKeyID, certSubjectKeyID)) {
            if (debug != null) {
                debug.println("X509CertSelector.match: subject key IDs " +
                    "don't match\nX509CertSelector.match: subjectKeyID: " +
                    Arrays.toString(subjectKeyID) +
                    "\nX509CertSelector.match: certSubjectKeyID: " +
                    Arrays.toString(certSubjectKeyID));
            }
            return false;
        }
    } catch (IOException ex) {
        if (debug != null) {
            debug.println("X509CertSelector.match: "
                + "exception in subject key ID check");
        }
        return false;
    }
    return true;
}
 

private static X509CertSelector generateSelector(String name)
            throws Exception {
    X509CertSelector selector = new X509CertSelector();

    // generate certificate from certificate string
    CertificateFactory cf = CertificateFactory.getInstance("X.509");
    ByteArrayInputStream is = null;
    if (name.equals("subca")) {
        is = new ByteArrayInputStream(subCaCertStr.getBytes());
    } else if (name.equals("subci")) {
        is = new ByteArrayInputStream(subCrlIssuerCertStr.getBytes());
    } else {
        is = new ByteArrayInputStream(targetCertStr.getBytes());
    }

    X509Certificate target = (X509Certificate)cf.generateCertificate(is);
    byte[] extVal = target.getExtensionValue("2.5.29.14");
    if (extVal != null) {
        DerInputStream in = new DerInputStream(extVal);
        byte[] subjectKID = in.getOctetString();
        selector.setSubjectKeyIdentifier(subjectKID);
    } else {
        // unlikely to happen.
        throw new Exception("unexpected certificate: no SKID extension");
    }

    return selector;
}
 

private static X509CertSelector generateSelector(String name)
            throws Exception {
    X509CertSelector selector = new X509CertSelector();

    // generate certificate from certificate string
    CertificateFactory cf = CertificateFactory.getInstance("X.509");
    ByteArrayInputStream is = null;
    if (name.equals("subca")) {
        is = new ByteArrayInputStream(subCaCertStr.getBytes());
    } else if (name.equals("subci")) {
        is = new ByteArrayInputStream(subCrlIssuerCertStr.getBytes());
    } else {
        is = new ByteArrayInputStream(targetCertStr.getBytes());
    }

    X509Certificate target = (X509Certificate)cf.generateCertificate(is);
    byte[] extVal = target.getExtensionValue("2.5.29.14");
    if (extVal != null) {
        DerInputStream in = new DerInputStream(extVal);
        byte[] subjectKID = in.getOctetString();
        selector.setSubjectKeyIdentifier(subjectKID);
    } else {
        // unlikely to happen.
        throw new Exception("unexpected certificate: no SKID extension");
    }

    return selector;
}
 

private static X509CertSelector generateSelector(String name)
            throws Exception {
    X509CertSelector selector = new X509CertSelector();

    // generate certificate from certificate string
    CertificateFactory cf = CertificateFactory.getInstance("X.509");
    ByteArrayInputStream is = null;
    if (name.equals("subca")) {
        is = new ByteArrayInputStream(subCaCertStr.getBytes());
    } else if (name.equals("subci")) {
        is = new ByteArrayInputStream(subCrlIssuerCertStr.getBytes());
    } else {
        is = new ByteArrayInputStream(targetCertStr.getBytes());
    }

    X509Certificate target = (X509Certificate)cf.generateCertificate(is);
    byte[] extVal = target.getExtensionValue("2.5.29.14");
    if (extVal != null) {
        DerInputStream in = new DerInputStream(extVal);
        byte[] subjectKID = in.getOctetString();
        selector.setSubjectKeyIdentifier(subjectKID);
    } else {
        // unlikely to happen.
        throw new Exception("unexpected certificate: no SKID extension");
    }

    return selector;
}
 

private static X509CertSelector generateSelector(String name)
            throws Exception {
    X509CertSelector selector = new X509CertSelector();

    // generate certificate from certificate string
    CertificateFactory cf = CertificateFactory.getInstance("X.509");
    ByteArrayInputStream is = null;
    if (name.equals("subca")) {
        is = new ByteArrayInputStream(subCaCertStr.getBytes());
    } else if (name.equals("subci")) {
        is = new ByteArrayInputStream(subCrlIssuerCertStr.getBytes());
    } else {
        is = new ByteArrayInputStream(targetCertStr.getBytes());
    }

    X509Certificate target = (X509Certificate)cf.generateCertificate(is);
    byte[] extVal = target.getExtensionValue("2.5.29.14");
    if (extVal != null) {
        DerInputStream in = new DerInputStream(extVal);
        byte[] subjectKID = in.getOctetString();
        selector.setSubjectKeyIdentifier(subjectKID);
    } else {
        // unlikely to happen.
        throw new Exception("unexpected certificate: no SKID extension");
    }

    return selector;
}
 

private boolean matchAuthorityKeyID(X509Certificate xcert) {
    if (authorityKeyID == null) {
        return true;
    }
    try {
        byte[] extVal = xcert.getExtensionValue("2.5.29.35");
        if (extVal == null) {
            if (debug != null) {
                debug.println("X509CertSelector.match: "
                    + "no authority key ID extension");
            }
            return false;
        }
        DerInputStream in = new DerInputStream(extVal);
        byte[] certAuthKeyID = in.getOctetString();
        if (certAuthKeyID == null ||
                !Arrays.equals(authorityKeyID, certAuthKeyID)) {
            if (debug != null) {
                debug.println("X509CertSelector.match: "
                    + "authority key IDs don't match");
            }
            return false;
        }
    } catch (IOException ex) {
        if (debug != null) {
            debug.println("X509CertSelector.match: "
                + "exception in authority key ID check");
        }
        return false;
    }
    return true;
}
 

private void testSubjectKeyIdentifier() throws IOException {
    System.out.println("X.509 Certificate Match on subjectKeyIdentifier");
    // bad match
    X509CertSelector selector = new X509CertSelector();
    byte[] b = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
    selector.setSubjectKeyIdentifier(b);
    checkMatch(selector, cert, false);

    // good match
    DerInputStream in = new DerInputStream(cert.getExtensionValue("2.5.29.14"));
    byte[] encoded = in.getOctetString();
    selector.setSubjectKeyIdentifier(encoded);
    checkMatch(selector, cert, true);
}
 

private boolean matchAuthorityKeyID(X509Certificate xcert) {
    if (authorityKeyID == null) {
        return true;
    }
    try {
        byte[] extVal = xcert.getExtensionValue("2.5.29.35");
        if (extVal == null) {
            if (debug != null) {
                debug.println("X509CertSelector.match: "
                    + "no authority key ID extension");
            }
            return false;
        }
        DerInputStream in = new DerInputStream(extVal);
        byte[] certAuthKeyID = in.getOctetString();
        if (certAuthKeyID == null ||
                !Arrays.equals(authorityKeyID, certAuthKeyID)) {
            if (debug != null) {
                debug.println("X509CertSelector.match: "
                    + "authority key IDs don't match");
            }
            return false;
        }
    } catch (IOException ex) {
        if (debug != null) {
            debug.println("X509CertSelector.match: "
                + "exception in authority key ID check");
        }
        return false;
    }
    return true;
}
 

private static X509CertSelector generateSelector(String name)
            throws Exception {
    X509CertSelector selector = new X509CertSelector();

    // generate certificate from certificate string
    CertificateFactory cf = CertificateFactory.getInstance("X.509");
    ByteArrayInputStream is = null;
    if (name.equals("subca")) {
        is = new ByteArrayInputStream(subCaCertStr.getBytes());
    } else if (name.equals("subci")) {
        is = new ByteArrayInputStream(subCrlIssuerCertStr.getBytes());
    } else {
        is = new ByteArrayInputStream(targetCertStr.getBytes());
    }

    X509Certificate target = (X509Certificate)cf.generateCertificate(is);
    byte[] extVal = target.getExtensionValue("2.5.29.14");
    if (extVal != null) {
        DerInputStream in = new DerInputStream(extVal);
        byte[] subjectKID = in.getOctetString();
        selector.setSubjectKeyIdentifier(subjectKID);
    } else {
        // unlikely to happen.
        throw new Exception("unexpected certificate: no SKID extension");
    }

    return selector;
}
 

/**
 * Returns an Extension object given any X509Certificate and extension oid.
 * Throw an {@code IOException} if the extension byte value is
 * malformed.
 *
 * @param cert a {@code X509Certificate}
 * @param extId an {@code integer} which specifies the extension index.
 * Currently, the supported extensions are as follows:
 * index 0 - PrivateKeyUsageExtension
 * index 1 - SubjectAlternativeNameExtension
 * index 2 - NameConstraintsExtension
 * index 3 - CertificatePoliciesExtension
 * index 4 - ExtendedKeyUsageExtension
 * @return an {@code Extension} object whose real type is as specified
 * by the extension oid.
 * @throws IOException if cannot construct the {@code Extension}
 * object with the extension encoding retrieved from the passed in
 * {@code X509Certificate}.
 */
private static Extension getExtensionObject(X509Certificate cert, int extId)
        throws IOException {
    if (cert instanceof X509CertImpl) {
        X509CertImpl impl = (X509CertImpl)cert;
        switch (extId) {
        case PRIVATE_KEY_USAGE_ID:
            return impl.getPrivateKeyUsageExtension();
        case SUBJECT_ALT_NAME_ID:
            return impl.getSubjectAlternativeNameExtension();
        case NAME_CONSTRAINTS_ID:
            return impl.getNameConstraintsExtension();
        case CERT_POLICIES_ID:
            return impl.getCertificatePoliciesExtension();
        case EXTENDED_KEY_USAGE_ID:
            return impl.getExtendedKeyUsageExtension();
        default:
            return null;
        }
    }
    byte[] rawExtVal = cert.getExtensionValue(EXTENSION_OIDS[extId]);
    if (rawExtVal == null) {
        return null;
    }
    DerInputStream in = new DerInputStream(rawExtVal);
    byte[] encoded = in.getOctetString();
    switch (extId) {
    case PRIVATE_KEY_USAGE_ID:
        try {
            return new PrivateKeyUsageExtension(FALSE, encoded);
        } catch (CertificateException ex) {
            throw new IOException(ex.getMessage());
        }
    case SUBJECT_ALT_NAME_ID:
        return new SubjectAlternativeNameExtension(FALSE, encoded);
    case NAME_CONSTRAINTS_ID:
        return new NameConstraintsExtension(FALSE, encoded);
    case CERT_POLICIES_ID:
        return new CertificatePoliciesExtension(FALSE, encoded);
    case EXTENDED_KEY_USAGE_ID:
        return new ExtendedKeyUsageExtension(FALSE, encoded);
    default:
        return null;
    }
}
 

/**
 * Returns an Extension object given any X509Certificate and extension oid.
 * Throw an <code>IOException</code> if the extension byte value is
 * malformed.
 *
 * @param cert a <code>X509Certificate</code>
 * @param extId an <code>integer</code> which specifies the extension index.
 * Currently, the supported extensions are as follows:
 * index 0 - PrivateKeyUsageExtension
 * index 1 - SubjectAlternativeNameExtension
 * index 2 - NameConstraintsExtension
 * index 3 - CertificatePoliciesExtension
 * index 4 - ExtendedKeyUsageExtension
 * @return an <code>Extension</code> object whose real type is as specified
 * by the extension oid.
 * @throws IOException if cannot construct the <code>Extension</code>
 * object with the extension encoding retrieved from the passed in
 * <code>X509Certificate</code>.
 */
private static Extension getExtensionObject(X509Certificate cert, int extId)
        throws IOException {
    if (cert instanceof X509CertImpl) {
        X509CertImpl impl = (X509CertImpl)cert;
        switch (extId) {
        case PRIVATE_KEY_USAGE_ID:
            return impl.getPrivateKeyUsageExtension();
        case SUBJECT_ALT_NAME_ID:
            return impl.getSubjectAlternativeNameExtension();
        case NAME_CONSTRAINTS_ID:
            return impl.getNameConstraintsExtension();
        case CERT_POLICIES_ID:
            return impl.getCertificatePoliciesExtension();
        case EXTENDED_KEY_USAGE_ID:
            return impl.getExtendedKeyUsageExtension();
        default:
            return null;
        }
    }
    byte[] rawExtVal = cert.getExtensionValue(EXTENSION_OIDS[extId]);
    if (rawExtVal == null) {
        return null;
    }
    DerInputStream in = new DerInputStream(rawExtVal);
    byte[] encoded = in.getOctetString();
    switch (extId) {
    case PRIVATE_KEY_USAGE_ID:
        try {
            return new PrivateKeyUsageExtension(FALSE, encoded);
        } catch (CertificateException ex) {
            throw new IOException(ex.getMessage());
        }
    case SUBJECT_ALT_NAME_ID:
        return new SubjectAlternativeNameExtension(FALSE, encoded);
    case NAME_CONSTRAINTS_ID:
        return new NameConstraintsExtension(FALSE, encoded);
    case CERT_POLICIES_ID:
        return new CertificatePoliciesExtension(FALSE, encoded);
    case EXTENDED_KEY_USAGE_ID:
        return new ExtendedKeyUsageExtension(FALSE, encoded);
    default:
        return null;
    }
}
 

/**
 * Returns an Extension object given any X509Certificate and extension oid.
 * Throw an {@code IOException} if the extension byte value is
 * malformed.
 *
 * @param cert a {@code X509Certificate}
 * @param extId an {@code integer} which specifies the extension index.
 * Currently, the supported extensions are as follows:
 * index 0 - PrivateKeyUsageExtension
 * index 1 - SubjectAlternativeNameExtension
 * index 2 - NameConstraintsExtension
 * index 3 - CertificatePoliciesExtension
 * index 4 - ExtendedKeyUsageExtension
 * @return an {@code Extension} object whose real type is as specified
 * by the extension oid.
 * @throws IOException if cannot construct the {@code Extension}
 * object with the extension encoding retrieved from the passed in
 * {@code X509Certificate}.
 */
private static Extension getExtensionObject(X509Certificate cert, int extId)
        throws IOException {
    if (cert instanceof X509CertImpl) {
        X509CertImpl impl = (X509CertImpl)cert;
        switch (extId) {
        case PRIVATE_KEY_USAGE_ID:
            return impl.getPrivateKeyUsageExtension();
        case SUBJECT_ALT_NAME_ID:
            return impl.getSubjectAlternativeNameExtension();
        case NAME_CONSTRAINTS_ID:
            return impl.getNameConstraintsExtension();
        case CERT_POLICIES_ID:
            return impl.getCertificatePoliciesExtension();
        case EXTENDED_KEY_USAGE_ID:
            return impl.getExtendedKeyUsageExtension();
        default:
            return null;
        }
    }
    byte[] rawExtVal = cert.getExtensionValue(EXTENSION_OIDS[extId]);
    if (rawExtVal == null) {
        return null;
    }
    DerInputStream in = new DerInputStream(rawExtVal);
    byte[] encoded = in.getOctetString();
    switch (extId) {
    case PRIVATE_KEY_USAGE_ID:
        try {
            return new PrivateKeyUsageExtension(FALSE, encoded);
        } catch (CertificateException ex) {
            throw new IOException(ex.getMessage());
        }
    case SUBJECT_ALT_NAME_ID:
        return new SubjectAlternativeNameExtension(FALSE, encoded);
    case NAME_CONSTRAINTS_ID:
        return new NameConstraintsExtension(FALSE, encoded);
    case CERT_POLICIES_ID:
        return new CertificatePoliciesExtension(FALSE, encoded);
    case EXTENDED_KEY_USAGE_ID:
        return new ExtendedKeyUsageExtension(FALSE, encoded);
    default:
        return null;
    }
}
 

/**
 * Returns an Extension object given any X509Certificate and extension oid.
 * Throw an {@code IOException} if the extension byte value is
 * malformed.
 *
 * @param cert a {@code X509Certificate}
 * @param extId an {@code integer} which specifies the extension index.
 * Currently, the supported extensions are as follows:
 * index 0 - PrivateKeyUsageExtension
 * index 1 - SubjectAlternativeNameExtension
 * index 2 - NameConstraintsExtension
 * index 3 - CertificatePoliciesExtension
 * index 4 - ExtendedKeyUsageExtension
 * @return an {@code Extension} object whose real type is as specified
 * by the extension oid.
 * @throws IOException if cannot construct the {@code Extension}
 * object with the extension encoding retrieved from the passed in
 * {@code X509Certificate}.
 */
private static Extension getExtensionObject(X509Certificate cert, int extId)
        throws IOException {
    if (cert instanceof X509CertImpl) {
        X509CertImpl impl = (X509CertImpl)cert;
        switch (extId) {
        case PRIVATE_KEY_USAGE_ID:
            return impl.getPrivateKeyUsageExtension();
        case SUBJECT_ALT_NAME_ID:
            return impl.getSubjectAlternativeNameExtension();
        case NAME_CONSTRAINTS_ID:
            return impl.getNameConstraintsExtension();
        case CERT_POLICIES_ID:
            return impl.getCertificatePoliciesExtension();
        case EXTENDED_KEY_USAGE_ID:
            return impl.getExtendedKeyUsageExtension();
        default:
            return null;
        }
    }
    byte[] rawExtVal = cert.getExtensionValue(EXTENSION_OIDS[extId]);
    if (rawExtVal == null) {
        return null;
    }
    DerInputStream in = new DerInputStream(rawExtVal);
    byte[] encoded = in.getOctetString();
    switch (extId) {
    case PRIVATE_KEY_USAGE_ID:
        try {
            return new PrivateKeyUsageExtension(FALSE, encoded);
        } catch (CertificateException ex) {
            throw new IOException(ex.getMessage());
        }
    case SUBJECT_ALT_NAME_ID:
        return new SubjectAlternativeNameExtension(FALSE, encoded);
    case NAME_CONSTRAINTS_ID:
        return new NameConstraintsExtension(FALSE, encoded);
    case CERT_POLICIES_ID:
        return new CertificatePoliciesExtension(FALSE, encoded);
    case EXTENDED_KEY_USAGE_ID:
        return new ExtendedKeyUsageExtension(FALSE, encoded);
    default:
        return null;
    }
}
 

/**
 * Parses a PKCS#7 signer info.
 *
 * <p>This constructor is used only for backwards compatibility with
 * PKCS#7 blocks that were generated using JDK1.1.x.
 *
 * @param derin the ASN.1 encoding of the signer info.
 * @param oldStyle flag indicating whether or not the given signer info
 * is encoded according to JDK1.1.x.
 */
public SignerInfo(DerInputStream derin, boolean oldStyle)
    throws IOException, ParsingException
{
    // version
    version = derin.getBigInteger();

    // issuerAndSerialNumber
    DerValue[] issuerAndSerialNumber = derin.getSequence(2);
    byte[] issuerBytes = issuerAndSerialNumber[0].toByteArray();
    issuerName = new X500Name(new DerValue(DerValue.tag_Sequence,
                                           issuerBytes));
    certificateSerialNumber = issuerAndSerialNumber[1].getBigInteger();

    // digestAlgorithmId
    DerValue tmp = derin.getDerValue();

    digestAlgorithmId = AlgorithmId.parse(tmp);

    // authenticatedAttributes
    if (oldStyle) {
        // In JDK1.1.x, the authenticatedAttributes are always present,
        // encoded as an empty Set (Set of length zero)
        derin.getSet(0);
    } else {
        // check if set of auth attributes (implicit tag) is provided
        // (auth attributes are OPTIONAL)
        if ((byte)(derin.peekByte()) == (byte)0xA0) {
            authenticatedAttributes = new PKCS9Attributes(derin);
        }
    }

    // digestEncryptionAlgorithmId - little RSA naming scheme -
    // signature == encryption...
    tmp = derin.getDerValue();

    digestEncryptionAlgorithmId = AlgorithmId.parse(tmp);

    // encryptedDigest
    encryptedDigest = derin.getOctetString();

    // unauthenticatedAttributes
    if (oldStyle) {
        // In JDK1.1.x, the unauthenticatedAttributes are always present,
        // encoded as an empty Set (Set of length zero)
        derin.getSet(0);
    } else {
        // check if set of unauth attributes (implicit tag) is provided
        // (unauth attributes are OPTIONAL)
        if (derin.available() != 0
            && (byte)(derin.peekByte()) == (byte)0xA1) {
            unauthenticatedAttributes =
                new PKCS9Attributes(derin, true);// ignore unsupported attrs
        }
    }

    // all done
    if (derin.available() != 0) {
        throw new ParsingException("extra data at the end");
    }
}