* 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 X509Certificate or as
* individual parameters.
*
* Concurrent Access *
*
All TrustAnchor objects must be immutable and
* thread-safe. That is, multiple threads may concurrently invoke the
* methods defined in this class on a single TrustAnchor
* object (or more than one) with no ill effects. Requiring
* TrustAnchor 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)
*
* @since 1.4
* @author Sean Mullan
*/
public class TrustAnchor {
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 TrustAnchor with the specified
* X509Certificate and optional name constraints, which
* are intended to be used as additional constraints when validating
* an X.509 certification path.
*
* 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 3280 * and X.509. The ASN.1 definition of this structure appears below. * *
* 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}
*
* Note that the name constraints byte array supplied is cloned to protect
* against subsequent modifications.
*
* @param trustedCert a trusted X509Certificate
* @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 null to omit the parameter.
* @throws IllegalArgumentException if the name constraints cannot be
* decoded
* @throws NullPointerException if the specified
* X509Certificate is null
*/
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 TrustAnchor 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.
*
* 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 3280 * 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) }. *
* 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 null to omit the parameter.
* @throws NullPointerException if the specified caPrincipal or
* pubKey parameter is null
* @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 TrustAnchor 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.
*
* 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 3280 * 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) }. *
* 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
* String 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 null to omit the parameter.
* @throws IllegalArgumentException if the specified
* caName parameter is empty (caName.length() == 0)
* or incorrectly formatted or the name constraints cannot be decoded
* @throws NullPointerException if the specified caName or
* pubKey parameter is null
*/
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 X509Certificate or null
* 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
* null 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 String
* format.
*
* @return the X.500 distinguished name of the most-trusted CA, or
* null 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 null
* 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 = 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.
*
* 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 3280 * 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) }. *
* 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 null if not set.
*/
public final byte [] getNameConstraints() {
return ncBytes == null ? null : ncBytes.clone();
}
/**
* Returns a formatted string describing the TrustAnchor.
*
* @return a formatted string describing the TrustAnchor
*/
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();
}
}