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package sun.security.x509;

import java.io.IOException;
import java.io.OutputStream;
import java.util.Enumeration;

import sun.security.util.*;

This class represents the Authority Key Identifier Extension.

The authority key identifier extension provides a means of identifying the particular public key used to sign a certificate. This extension would be used where an issuer has multiple signing keys (either due to multiple concurrent key pairs or due to changeover).

The ASN.1 syntax for this is:

AuthorityKeyIdentifier ::= SEQUENCE {
   keyIdentifier             [0] KeyIdentifier           OPTIONAL,
   authorityCertIssuer       [1] GeneralNames            OPTIONAL,
   authorityCertSerialNumber [2] CertificateSerialNumber OPTIONAL
}
KeyIdentifier ::= OCTET STRING
Author:Amit Kapoor, Hemma Prafullchandra
See Also:
/** * This class represents the Authority Key Identifier Extension. * * <p>The authority key identifier extension provides a means of * identifying the particular public key used to sign a certificate. * This extension would be used where an issuer has multiple signing * keys (either due to multiple concurrent key pairs or due to * changeover). * <p> * The ASN.1 syntax for this is: * <pre> * AuthorityKeyIdentifier ::= SEQUENCE { * keyIdentifier [0] KeyIdentifier OPTIONAL, * authorityCertIssuer [1] GeneralNames OPTIONAL, * authorityCertSerialNumber [2] CertificateSerialNumber OPTIONAL * } * KeyIdentifier ::= OCTET STRING * </pre> * @author Amit Kapoor * @author Hemma Prafullchandra * @see Extension * @see CertAttrSet */
public class AuthorityKeyIdentifierExtension 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.AuthorityKeyIdentifier";
Attribute names.
/** * Attribute names. */
public static final String NAME = "AuthorityKeyIdentifier"; public static final String KEY_ID = "key_id"; public static final String AUTH_NAME = "auth_name"; public static final String SERIAL_NUMBER = "serial_number"; // Private data members private static final byte TAG_ID = 0; private static final byte TAG_NAMES = 1; private static final byte TAG_SERIAL_NUM = 2; private KeyIdentifier id = null; private GeneralNames names = null; private SerialNumber serialNum = null; // Encode only the extension value private void encodeThis() throws IOException { if (id == null && names == null && serialNum == null) { this.extensionValue = null; return; } DerOutputStream seq = new DerOutputStream(); DerOutputStream tmp = new DerOutputStream(); if (id != null) { DerOutputStream tmp1 = new DerOutputStream(); id.encode(tmp1); tmp.writeImplicit(DerValue.createTag(DerValue.TAG_CONTEXT, false, TAG_ID), tmp1); } try { if (names != null) { DerOutputStream tmp1 = new DerOutputStream(); names.encode(tmp1); tmp.writeImplicit(DerValue.createTag(DerValue.TAG_CONTEXT, true, TAG_NAMES), tmp1); } } catch (Exception e) { throw new IOException(e.toString()); } if (serialNum != null) { DerOutputStream tmp1 = new DerOutputStream(); serialNum.encode(tmp1); tmp.writeImplicit(DerValue.createTag(DerValue.TAG_CONTEXT, false, TAG_SERIAL_NUM), tmp1); } seq.write(DerValue.tag_Sequence, tmp); this.extensionValue = seq.toByteArray(); }
The default constructor for this extension. Null parameters make the element optional (not present).
Params:
  • id – the KeyIdentifier associated with this extension.
  • names – the GeneralNames associated with this extension
  • serialNum – the CertificateSerialNumber associated with this extension.
Throws:
/** * The default constructor for this extension. Null parameters make * the element optional (not present). * * @param id the KeyIdentifier associated with this extension. * @param names the GeneralNames associated with this extension * @param serialNum the CertificateSerialNumber associated with * this extension. * @exception IOException on error. */
public AuthorityKeyIdentifierExtension(KeyIdentifier kid, GeneralNames name, SerialNumber sn) throws IOException { this.id = kid; this.names = name; this.serialNum = sn; this.extensionId = PKIXExtensions.AuthorityKey_Id; this.critical = false; encodeThis(); }
Create the extension from the passed DER encoded value of the same.
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 the passed DER encoded value of the same. * * @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 AuthorityKeyIdentifierExtension(Boolean critical, Object value) throws IOException { this.extensionId = PKIXExtensions.AuthorityKey_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 " + "AuthorityKeyIdentifierExtension."); } // Note that all the fields in AuthorityKeyIdentifier are defined as // being OPTIONAL, i.e., there could be an empty SEQUENCE, resulting // in val.data being null. while ((val.data != null) && (val.data.available() != 0)) { DerValue opt = val.data.getDerValue(); // NB. this is always encoded with the IMPLICIT tag // The checks only make sense if we assume implicit tagging, // with explicit tagging the form is always constructed. if (opt.isContextSpecific(TAG_ID) && !opt.isConstructed()) { if (id != null) throw new IOException("Duplicate KeyIdentifier in " + "AuthorityKeyIdentifier."); opt.resetTag(DerValue.tag_OctetString); id = new KeyIdentifier(opt); } else if (opt.isContextSpecific(TAG_NAMES) && opt.isConstructed()) { if (names != null) throw new IOException("Duplicate GeneralNames in " + "AuthorityKeyIdentifier."); opt.resetTag(DerValue.tag_Sequence); names = new GeneralNames(opt); } else if (opt.isContextSpecific(TAG_SERIAL_NUM) && !opt.isConstructed()) { if (serialNum != null) throw new IOException("Duplicate SerialNumber in " + "AuthorityKeyIdentifier."); opt.resetTag(DerValue.tag_Integer); serialNum = new SerialNumber(opt); } else throw new IOException("Invalid encoding of " + "AuthorityKeyIdentifierExtension."); } }
Return the object as a string.
/** * Return the object as a string. */
public String toString() { String s = super.toString() + "AuthorityKeyIdentifier [\n"; if (id != null) { s += id.toString(); // id already has a newline } if (names != null) { s += names.toString() + "\n"; } if (serialNum != null) { s += serialNum.toString() + "\n"; } return (s + "]\n"); }
Write the extension to the OutputStream.
Params:
  • out – the OutputStream to write the extension to.
Throws:
/** * Write the extension to the OutputStream. * * @param out the OutputStream to write the extension to. * @exception IOException on error. */
public void encode(OutputStream out) throws IOException { DerOutputStream tmp = new DerOutputStream(); if (this.extensionValue == null) { extensionId = PKIXExtensions.AuthorityKey_Id; critical = false; encodeThis(); } super.encode(tmp); out.write(tmp.toByteArray()); }
Set the attribute value.
/** * Set the attribute value. */
public void set(String name, Object obj) throws IOException { if (name.equalsIgnoreCase(KEY_ID)) { if (!(obj instanceof KeyIdentifier)) { throw new IOException("Attribute value should be of " + "type KeyIdentifier."); } id = (KeyIdentifier)obj; } else if (name.equalsIgnoreCase(AUTH_NAME)) { if (!(obj instanceof GeneralNames)) { throw new IOException("Attribute value should be of " + "type GeneralNames."); } names = (GeneralNames)obj; } else if (name.equalsIgnoreCase(SERIAL_NUMBER)) { if (!(obj instanceof SerialNumber)) { throw new IOException("Attribute value should be of " + "type SerialNumber."); } serialNum = (SerialNumber)obj; } else { throw new IOException("Attribute name not recognized by " + "CertAttrSet:AuthorityKeyIdentifier."); } encodeThis(); }
Get the attribute value.
/** * Get the attribute value. */
public Object get(String name) throws IOException { if (name.equalsIgnoreCase(KEY_ID)) { return (id); } else if (name.equalsIgnoreCase(AUTH_NAME)) { return (names); } else if (name.equalsIgnoreCase(SERIAL_NUMBER)) { return (serialNum); } else { throw new IOException("Attribute name not recognized by " + "CertAttrSet:AuthorityKeyIdentifier."); } }
Delete the attribute value.
/** * Delete the attribute value. */
public void delete(String name) throws IOException { if (name.equalsIgnoreCase(KEY_ID)) { id = null; } else if (name.equalsIgnoreCase(AUTH_NAME)) { names = null; } else if (name.equalsIgnoreCase(SERIAL_NUMBER)) { serialNum = null; } else { throw new IOException("Attribute name not recognized by " + "CertAttrSet:AuthorityKeyIdentifier."); } 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(KEY_ID); elements.addElement(AUTH_NAME); elements.addElement(SERIAL_NUMBER); return (elements.elements()); }
Return the name of this attribute.
/** * Return the name of this attribute. */
public String getName() { return (NAME); } }