/*
* @(#)TrustAnchor.java 1.11 05/11/17
*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
package java.security.cert;
import java.io.IOException;
import java.security.PublicKey;
import javax.security.auth.x500.X500Principal;
import sun.security.x509.NameConstraintsExtension;
import sun.security.x509.X500Name;
/**
* A trust anchor or most-trusted Certification Authority (CA).
* <p>
* This class represents a "most-trusted CA", which is used as a trust anchor
* for validating X.509 certification paths. A most-trusted CA includes the
* public key of the CA, the CA's name, and any constraints upon the set of
* paths which may be validated using this key. These parameters can be
* specified in the form of a trusted <code>X509Certificate</code> or as
* individual parameters.
* <p>
* <b>Concurrent Access</b>
* <p>
* <p>All <code>TrustAnchor</code> objects must be immutable and
* thread-safe. That is, multiple threads may concurrently invoke the
* methods defined in this class on a single <code>TrustAnchor</code>
* object (or more than one) with no ill effects. Requiring
* <code>TrustAnchor</code> objects to be immutable and thread-safe
* allows them to be passed around to various pieces of code without
* worrying about coordinating access. This stipulation applies to all
* public fields and methods of this class and any added or overridden
* by subclasses.
*
* @see PKIXParameters#PKIXParameters(Set)
* @see PKIXBuilderParameters#PKIXBuilderParameters(Set, CertSelector)
*
* @version 1.11 11/17/05
* @since 1.4
* @author Sean Mullan
*/
public class TrustAnchor {
static {
CertPathHelperImpl.initialize();
}
private final PublicKey pubKey;
private final String caName;
private final X500Principal caPrincipal;
private final X509Certificate trustedCert;
private byte[] ncBytes;
private NameConstraintsExtension nc;
/**
* Creates an instance of <code>TrustAnchor</code> with the specified
* <code>X509Certificate</code> and optional name constraints, which
* are intended to be used as additional constraints when validating
* an X.509 certification path.
* <p>
* The name constraints are specified as a byte array. This byte array
* should contain the DER encoded form of the name constraints, as they
* would appear in the NameConstraints structure defined in RFC 2459
* and X.509. The ASN.1 definition of this structure appears below.
*
* <pre><code>
* NameConstraints ::= SEQUENCE {
* permittedSubtrees [0] GeneralSubtrees OPTIONAL,
* excludedSubtrees [1] GeneralSubtrees OPTIONAL }
*
* GeneralSubtrees ::= SEQUENCE SIZE (1..MAX) OF GeneralSubtree
*
* GeneralSubtree ::= SEQUENCE {
* base GeneralName,
* minimum [0] BaseDistance DEFAULT 0,
* maximum [1] BaseDistance OPTIONAL }
*
* BaseDistance ::= INTEGER (0..MAX)
*
* GeneralName ::= CHOICE {
* otherName [0] OtherName,
* rfc822Name [1] IA5String,
* dNSName [2] IA5String,
* x400Address [3] ORAddress,
* directoryName [4] Name,
* ediPartyName [5] EDIPartyName,
* uniformResourceIdentifier [6] IA5String,
* iPAddress [7] OCTET STRING,
* registeredID [8] OBJECT IDENTIFIER}
* </code></pre>
* <p>
* Note that the name constraints byte array supplied is cloned to protect
* against subsequent modifications.
*
* @param trustedCert a trusted <code>X509Certificate</code>
* @param nameConstraints a byte array containing the ASN.1 DER encoding of
* a NameConstraints extension to be used for checking name constraints.
* Only the value of the extension is included, not the OID or criticality
* flag. Specify <code>null</code> to omit the parameter.
* @throws IllegalArgumentException if the name constraints cannot be
* decoded
* @throws NullPointerException if the specified
* <code>X509Certificate</code> is <code>null</code>
*/
public TrustAnchor(X509Certificate trustedCert, byte[] nameConstraints)
{
if (trustedCert == null)
throw new NullPointerException("the trustedCert parameter must " +
"be non-null");
this.trustedCert = trustedCert;
this.pubKey = null;
this.caName = null;
this.caPrincipal = null;
setNameConstraints(nameConstraints);
}
/**
* Creates an instance of <code>TrustAnchor</code> where the
* most-trusted CA is specified as an X500Principal and public key.
* Name constraints are an optional parameter, and are intended to be used
* as additional constraints when validating an X.509 certification path.
* <p>
* The name constraints are specified as a byte array. This byte array
* contains the DER encoded form of the name constraints, as they
* would appear in the NameConstraints structure defined in RFC 2459
* and X.509. The ASN.1 notation for this structure is supplied in the
* documentation for
* {@link #TrustAnchor(X509Certificate, byte[])
* TrustAnchor(X509Certificate trustedCert, byte[] nameConstraints) }.
* <p>
* Note that the name constraints byte array supplied here is cloned to
* protect against subsequent modifications.
*
* @param caPrincipal the name of the most-trusted CA as X500Principal
* @param pubKey the public key of the most-trusted CA
* @param nameConstraints a byte array containing the ASN.1 DER encoding of
* a NameConstraints extension to be used for checking name constraints.
* Only the value of the extension is included, not the OID or criticality
* flag. Specify <code>null</code> to omit the parameter.
* @throws NullPointerException if the specified <code>caPrincipal</code> or
* <code>pubKey</code> parameter is <code>null</code>
* @since 1.5
*/
public TrustAnchor(X500Principal caPrincipal, PublicKey pubKey,
byte[] nameConstraints) {
if ((caPrincipal == null) || (pubKey == null)) {
throw new NullPointerException();
}
this.trustedCert = null;
this.caPrincipal = caPrincipal;
this.caName = caPrincipal.getName();
this.pubKey = pubKey;
setNameConstraints(nameConstraints);
}
/**
* Creates an instance of <code>TrustAnchor</code> where the
* most-trusted CA is specified as a distinguished name and public key.
* Name constraints are an optional parameter, and are intended to be used
* as additional constraints when validating an X.509 certification path.
* <p>
* The name constraints are specified as a byte array. This byte array
* contains the DER encoded form of the name constraints, as they
* would appear in the NameConstraints structure defined in RFC 2459
* and X.509. The ASN.1 notation for this structure is supplied in the
* documentation for
* {@link #TrustAnchor(X509Certificate, byte[])
* TrustAnchor(X509Certificate trustedCert, byte[] nameConstraints) }.
* <p>
* Note that the name constraints byte array supplied here is cloned to
* protect against subsequent modifications.
*
* @param caName the X.500 distinguished name of the most-trusted CA in
* RFC 2253 <code>String</code> format
* @param pubKey the public key of the most-trusted CA
* @param nameConstraints a byte array containing the ASN.1 DER encoding of
* a NameConstraints extension to be used for checking name constraints.
* Only the value of the extension is included, not the OID or criticality
* flag. Specify <code>null</code> to omit the parameter.
* @throws IllegalArgumentException if the specified <code>
* caName</code> parameter is empty <code>(caName.length() == 0)</code>
* or incorrectly formatted or the name constraints cannot be decoded
* @throws NullPointerException if the specified <code>caName</code> or
* <code>pubKey</code> parameter is <code>null</code>
*/
public TrustAnchor(String caName, PublicKey pubKey, byte[] nameConstraints)
{
if (pubKey == null)
throw new NullPointerException("the pubKey parameter must be " +
"non-null");
if (caName == null)
throw new NullPointerException("the caName parameter must be " +
"non-null");
if (caName.length() == 0)
throw new IllegalArgumentException("the caName " +
"parameter must be a non-empty String");
// check if caName is formatted correctly
this.caPrincipal = new X500Principal(caName);
this.pubKey = pubKey;
this.caName = caName;
this.trustedCert = null;
setNameConstraints(nameConstraints);
}
/**
* Returns the most-trusted CA certificate.
*
* @return a trusted <code>X509Certificate</code> or <code>null</code>
* if the trust anchor was not specified as a trusted certificate
*/
public final X509Certificate getTrustedCert() {
return this.trustedCert;
}
/**
* Returns the name of the most-trusted CA as an X500Principal.
*
* @return the X.500 distinguished name of the most-trusted CA, or
* <code>null</code> if the trust anchor was not specified as a trusted
* public key and name or X500Principal pair
* @since 1.5
*/
public final X500Principal getCA() {
return this.caPrincipal;
}
/**
* Returns the name of the most-trusted CA in RFC 2253 <code>String</code>
* format.
*
* @return the X.500 distinguished name of the most-trusted CA, or
* <code>null</code> if the trust anchor was not specified as a trusted
* public key and name or X500Principal pair
*/
public final String getCAName() {
return this.caName;
}
/**
* Returns the public key of the most-trusted CA.
*
* @return the public key of the most-trusted CA, or <code>null</code>
* if the trust anchor was not specified as a trusted public key and name
* or X500Principal pair
*/
public final PublicKey getCAPublicKey() {
return this.pubKey;
}
/**
* Decode the name constraints and clone them if not null.
*/
private void setNameConstraints(byte[] bytes) {
if (bytes == null) {
ncBytes = null;
nc = null;
} else {
ncBytes = (byte []) bytes.clone();
// validate DER encoding
try {
nc = new NameConstraintsExtension(Boolean.FALSE, bytes);
} catch (IOException ioe) {
IllegalArgumentException iae =
new IllegalArgumentException(ioe.getMessage());
iae.initCause(ioe);
throw iae;
}
}
}
/**
* Returns the name constraints parameter. The specified name constraints
* are associated with this trust anchor and are intended to be used
* as additional constraints when validating an X.509 certification path.
* <p>
* The name constraints are returned as a byte array. This byte array
* contains the DER encoded form of the name constraints, as they
* would appear in the NameConstraints structure defined in RFC 2459
* and X.509. The ASN.1 notation for this structure is supplied in the
* documentation for
* {@link #TrustAnchor(X509Certificate, byte[])
* TrustAnchor(X509Certificate trustedCert, byte[] nameConstraints) }.
* <p>
* Note that the byte array returned is cloned to protect against
* subsequent modifications.
*
* @return a byte array containing the ASN.1 DER encoding of
* a NameConstraints extension used for checking name constraints,
* or <code>null</code> if not set.
*/
public final byte [] getNameConstraints() {
return (ncBytes == null ? null : (byte []) ncBytes.clone());
}
/**
* Returns a formatted string describing the <code>TrustAnchor</code>.
*
* @return a formatted string describing the <code>TrustAnchor</code>
*/
public String toString() {
StringBuffer sb = new StringBuffer();
sb.append("[\n");
if (pubKey != null) {
sb.append(" Trusted CA Public Key: " + pubKey.toString() + "\n");
sb.append(" Trusted CA Issuer Name: "
+ String.valueOf(caName) + "\n");
} else {
sb.append(" Trusted CA cert: " + trustedCert.toString() + "\n");
}
if (nc != null)
sb.append(" Name Constraints: " + nc.toString() + "\n");
return sb.toString();
}
}