https://openjdk.java.net/ 
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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package sun.security.x509;

import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Vector;

import sun.security.util.DerValue;
import sun.security.util.DerOutputStream;
import sun.security.util.ObjectIdentifier;


This class defines the Extended Key Usage Extension, which
indicates one or more purposes for which the certified public key
may be used, in addition to or in place of the basic purposes
indicated in the key usage extension field.  This field is defined
as follows:

id-ce-extKeyUsage OBJECT IDENTIFIER ::= {id-ce 37}

ExtKeyUsageSyntax ::= SEQUENCE SIZE (1..MAX) OF KeyPurposeId

KeyPurposeId ::= OBJECT IDENTIFIER

Key purposes may be defined by any organization with a need. Object
identifiers used to identify key purposes shall be assigned in
accordance with IANA or ITU-T Rec. X.660 | ISO/IEC/ITU 9834-1.

This extension may, at the option of the certificate issuer, be
either critical or non-critical.

If the extension is flagged critical, then the certificate MUST be
used only for one of the purposes indicated.

If the extension is flagged non-critical, then it indicates the
intended purpose or purposes of the key, and may be used in finding
the correct key/certificate of an entity that has multiple
keys/certificates. It is an advisory field and does not imply that
usage of the key is restricted by the certification authority to
the purpose indicated. Certificate using applications may
nevertheless require that a particular purpose be indicated in
order for the certificate to be acceptable to that application.

If a certificate contains both a critical key usage field and a
critical extended key usage field, then both fields MUST be
processed independently and the certificate MUST only be used for a
purpose consistent with both fields.  If there is no purpose
consistent with both fields, then the certificate MUST NOT be used
for any purpose.

Since:      1.4
/**
 * This class defines the Extended Key Usage Extension, which
 * indicates one or more purposes for which the certified public key
 * may be used, in addition to or in place of the basic purposes
 * indicated in the key usage extension field.  This field is defined
 * as follows:<p>
 *
 * id-ce-extKeyUsage OBJECT IDENTIFIER ::= {id-ce 37}<p>
 *
 * ExtKeyUsageSyntax ::= SEQUENCE SIZE (1..MAX) OF KeyPurposeId<p>
 *
 * KeyPurposeId ::= OBJECT IDENTIFIER<p>
 *
 * Key purposes may be defined by any organization with a need. Object
 * identifiers used to identify key purposes shall be assigned in
 * accordance with IANA or ITU-T Rec. X.660 | ISO/IEC/ITU 9834-1.<p>
 *
 * This extension may, at the option of the certificate issuer, be
 * either critical or non-critical.<p>
 *
 * If the extension is flagged critical, then the certificate MUST be
 * used only for one of the purposes indicated.<p>
 *
 * If the extension is flagged non-critical, then it indicates the
 * intended purpose or purposes of the key, and may be used in finding
 * the correct key/certificate of an entity that has multiple
 * keys/certificates. It is an advisory field and does not imply that
 * usage of the key is restricted by the certification authority to
 * the purpose indicated. Certificate using applications may
 * nevertheless require that a particular purpose be indicated in
 * order for the certificate to be acceptable to that application.<p>

 * If a certificate contains both a critical key usage field and a
 * critical extended key usage field, then both fields MUST be
 * processed independently and the certificate MUST only be used for a
 * purpose consistent with both fields.  If there is no purpose
 * consistent with both fields, then the certificate MUST NOT be used
 * for any purpose.
 *
 * @since       1.4
 */
public class ExtendedKeyUsageExtension extends Extension
implements CertAttrSet<String> {

    
Identifier for this attribute, to be used with the
get, set, delete methods of Certificate, x509 type.

/**
     * Identifier for this attribute, to be used with the
     * get, set, delete methods of Certificate, x509 type.
     */
    public static final String IDENT = "x509.info.extensions.ExtendedKeyUsage";

    
Attribute names.

/**
     * Attribute names.
     */
    public static final String NAME = "ExtendedKeyUsage";
    public static final String USAGES = "usages";

    // OID defined in RFC 5280 Sections 4.2.1.12
    // more from http://www.alvestrand.no/objectid/1.3.6.1.5.5.7.3.html
    private static final Map <ObjectIdentifier, String> map =
            new HashMap <ObjectIdentifier, String> ();

    private static final int[] anyExtendedKeyUsageOidData = {2, 5, 29, 37, 0};
    private static final int[] serverAuthOidData = {1, 3, 6, 1, 5, 5, 7, 3, 1};
    private static final int[] clientAuthOidData = {1, 3, 6, 1, 5, 5, 7, 3, 2};
    private static final int[] codeSigningOidData = {1, 3, 6, 1, 5, 5, 7, 3, 3};
    private static final int[] emailProtectionOidData = {1, 3, 6, 1, 5, 5, 7, 3, 4};
    private static final int[] ipsecEndSystemOidData = {1, 3, 6, 1, 5, 5, 7, 3, 5};
    private static final int[] ipsecTunnelOidData = {1, 3, 6, 1, 5, 5, 7, 3, 6};
    private static final int[] ipsecUserOidData = {1, 3, 6, 1, 5, 5, 7, 3, 7};
    private static final int[] timeStampingOidData = {1, 3, 6, 1, 5, 5, 7, 3, 8};
    private static final int[] OCSPSigningOidData = {1, 3, 6, 1, 5, 5, 7, 3, 9};

    static {
        map.put(ObjectIdentifier.newInternal(anyExtendedKeyUsageOidData), "anyExtendedKeyUsage");
        map.put(ObjectIdentifier.newInternal(serverAuthOidData), "serverAuth");
        map.put(ObjectIdentifier.newInternal(clientAuthOidData), "clientAuth");
        map.put(ObjectIdentifier.newInternal(codeSigningOidData), "codeSigning");
        map.put(ObjectIdentifier.newInternal(emailProtectionOidData), "emailProtection");
        map.put(ObjectIdentifier.newInternal(ipsecEndSystemOidData), "ipsecEndSystem");
        map.put(ObjectIdentifier.newInternal(ipsecTunnelOidData), "ipsecTunnel");
        map.put(ObjectIdentifier.newInternal(ipsecUserOidData), "ipsecUser");
        map.put(ObjectIdentifier.newInternal(timeStampingOidData), "timeStamping");
        map.put(ObjectIdentifier.newInternal(OCSPSigningOidData), "OCSPSigning");
    };

    
Vector of KeyUsages for this object.

/**
     * Vector of KeyUsages for this object.
     */
    private Vector<ObjectIdentifier> keyUsages;

    // Encode this extension value.
    private void encodeThis() throws IOException {
        if (keyUsages == null || keyUsages.isEmpty()) {
            this.extensionValue = null;
            return;
        }
        DerOutputStream os = new DerOutputStream();
        DerOutputStream tmp = new DerOutputStream();

        for (int i = 0; i < keyUsages.size(); i++) {
            tmp.putOID(keyUsages.elementAt(i));
        }

        os.write(DerValue.tag_Sequence, tmp);
        this.extensionValue = os.toByteArray();
    }

    
Create a ExtendedKeyUsageExtension object from
a Vector of Key Usages; the criticality is set to false.

Params:
  • keyUsages – the Vector of KeyUsages (ObjectIdentifiers)
/**
     * Create a ExtendedKeyUsageExtension object from
     * a Vector of Key Usages; the criticality is set to false.
     *
     * @param keyUsages the Vector of KeyUsages (ObjectIdentifiers)
     */
    public ExtendedKeyUsageExtension(Vector<ObjectIdentifier> keyUsages)
    throws IOException {
        this(Boolean.FALSE, keyUsages);
    }

    
Create a ExtendedKeyUsageExtension object from
a Vector of KeyUsages with specified criticality.

Params:
  • critical – true if the extension is to be treated as critical.
  • keyUsages – the Vector of KeyUsages (ObjectIdentifiers)
/**
     * Create a ExtendedKeyUsageExtension object from
     * a Vector of KeyUsages with specified criticality.
     *
     * @param critical true if the extension is to be treated as critical.
     * @param keyUsages the Vector of KeyUsages (ObjectIdentifiers)
     */
    public ExtendedKeyUsageExtension(Boolean critical, Vector<ObjectIdentifier> keyUsages)
    throws IOException {
        this.keyUsages = keyUsages;
        this.extensionId = PKIXExtensions.ExtendedKeyUsage_Id;
        this.critical = critical.booleanValue();
        encodeThis();
    }

    
Create the extension from its DER encoded value and criticality.

Params:
  • critical – true if the extension is to be treated as critical.
  • value – an array of DER encoded bytes of the actual value.
Throws:
/**
     * Create the extension from its DER encoded value and criticality.
     *
     * @param critical true if the extension is to be treated as critical.
     * @param value an array of DER encoded bytes of the actual value.
     * @exception ClassCastException if value is not an array of bytes
     * @exception IOException on error.
     */
    public ExtendedKeyUsageExtension(Boolean critical, Object value)
    throws IOException {
        this.extensionId = PKIXExtensions.ExtendedKeyUsage_Id;
        this.critical = critical.booleanValue();
        this.extensionValue = (byte[]) value;
        DerValue val = new DerValue(this.extensionValue);
        if (val.tag != DerValue.tag_Sequence) {
            throw new IOException("Invalid encoding for " +
                                   "ExtendedKeyUsageExtension.");
        }
        keyUsages = new Vector<ObjectIdentifier>();
        while (val.data.available() != 0) {
            DerValue seq = val.data.getDerValue();
            ObjectIdentifier usage = seq.getOID();
            keyUsages.addElement(usage);
        }
    }

    
Return the extension as user readable string.

/**
     * Return the extension as user readable string.
     */
    public String toString() {
        if (keyUsages == null) return "";
        String usage = "  ";
        boolean first = true;
        for (ObjectIdentifier oid: keyUsages) {
            if(!first) {
                usage += "\n  ";
            }

            String result = map.get(oid);
            if (result != null) {
                usage += result;
            } else {
                usage += oid.toString();
            }
            first = false;
        }
        return super.toString() + "ExtendedKeyUsages [\n"
               + usage + "\n]\n";
    }

    
Write the extension to the DerOutputStream.

Params:
  • out – the DerOutputStream to write the extension to.
Throws:
/**
     * Write the extension to the DerOutputStream.
     *
     * @param out the DerOutputStream to write the extension to.
     * @exception IOException on encoding errors.
     */
    public void encode(OutputStream out) throws IOException {
        DerOutputStream tmp = new DerOutputStream();
        if (extensionValue == null) {
          extensionId = PKIXExtensions.ExtendedKeyUsage_Id;
          critical = false;
          encodeThis();
        }
        super.encode(tmp);
        out.write(tmp.toByteArray());
    }

    
Set the attribute value.

/**
     * Set the attribute value.
     */
    @SuppressWarnings("unchecked") // Checked with instanceof
    public void set(String name, Object obj) throws IOException {
        if (name.equalsIgnoreCase(USAGES)) {
            if (!(obj instanceof Vector)) {
                throw new IOException("Attribute value should be of type Vector.");
            }
            this.keyUsages = (Vector<ObjectIdentifier>)obj;
        } else {
          throw new IOException("Attribute name [" + name +
                                "] not recognized by " +
                                "CertAttrSet:ExtendedKeyUsageExtension.");
        }
        encodeThis();
    }

    
Get the attribute value.

/**
     * Get the attribute value.
     */
    public Vector<ObjectIdentifier> get(String name) throws IOException {
        if (name.equalsIgnoreCase(USAGES)) {
            //XXXX May want to consider cloning this
            return keyUsages;
        } else {
          throw new IOException("Attribute name [" + name +
                                "] not recognized by " +
                                "CertAttrSet:ExtendedKeyUsageExtension.");
        }
    }

    
Delete the attribute value.

/**
     * Delete the attribute value.
     */
    public void delete(String name) throws IOException {
        if (name.equalsIgnoreCase(USAGES)) {
            keyUsages = null;
        } else {
          throw new IOException("Attribute name [" + name +
                                "] not recognized by " +
                                "CertAttrSet:ExtendedKeyUsageExtension.");
        }
        encodeThis();
    }

    
Return an enumeration of names of attributes existing within this
attribute.

/**
     * Return an enumeration of names of attributes existing within this
     * attribute.
     */
    public Enumeration<String> getElements() {
        AttributeNameEnumeration elements = new AttributeNameEnumeration();
        elements.addElement(USAGES);

        return (elements.elements());
    }

    
Return the name of this attribute.

/**
     * Return the name of this attribute.
     */
    public String getName() {
        return (NAME);
    }

    public List<String> getExtendedKeyUsage() {
        List<String> al = new ArrayList<String>(keyUsages.size());
        for (ObjectIdentifier oid : keyUsages) {
            al.add(oid.toString());
        }
        return al;
    }

}