Class TrustAnchor

public class TrustAnchor
extends Object

A trust anchor or most-trusted Certification Authority (CA).

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.

Since:
1.4
See Also:
PKIXParameters(Set), PKIXBuilderParameters(Set, CertSelector)

Constructor Summary

Constructors
Constructor Description
TrustAnchor​(String caName, PublicKey pubKey, byte[] nameConstraints)

Creates an instance of TrustAnchor where the most-trusted CA is specified as a distinguished name and public key.
TrustAnchor​(X509Certificate trustedCert, byte[] nameConstraints)

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.
TrustAnchor​(X500Principal caPrincipal, PublicKey pubKey, byte[] nameConstraints)

Creates an instance of TrustAnchor where the most-trusted CA is specified as an X500Principal and public key.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type Method Description
X500Principal getCA()

Returns the name of the most-trusted CA as an X500Principal.
String getCAName()

Returns the name of the most-trusted CA in RFC 2253 String format.
PublicKey getCAPublicKey()

Returns the public key of the most-trusted CA.
byte[] getNameConstraints()

Returns the name constraints parameter.
X509Certificate getTrustedCert()

Returns the most-trusted CA certificate.
String toString()

Returns a formatted string describing the TrustAnchor.

Methods declared in class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

TrustAnchor

public TrustAnchor​(X509Certificate trustedCert,
                   byte[] nameConstraints)

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 5280 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.

Parameters:
trustedCert - a trusted X509Certificate
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
NullPointerException - if the specified X509Certificate is null

TrustAnchor

public TrustAnchor​(X500Principal caPrincipal,
                   PublicKey pubKey,
                   byte[] 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 5280 and X.509. The ASN.1 notation for this structure is supplied in the documentation for TrustAnchor(X509Certificate trustedCert, byte[] nameConstraints) .

Note that the name constraints byte array supplied here is cloned to protect against subsequent modifications.

Parameters:
caPrincipal - the name of the most-trusted CA as X500Principal
pubKey - the public key of the most-trusted CA
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

TrustAnchor

public TrustAnchor​(String caName,
                   PublicKey pubKey,
                   byte[] 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 5280 and X.509. The ASN.1 notation for this structure is supplied in the documentation for TrustAnchor(X509Certificate trustedCert, byte[] nameConstraints) .

Note that the name constraints byte array supplied here is cloned to protect against subsequent modifications.

Parameters:
caName - the X.500 distinguished name of the most-trusted CA in RFC 2253 String format
pubKey - the public key of the most-trusted CA
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
NullPointerException - if the specified caName or pubKey parameter is null

Method Detail

getTrustedCert

public final X509Certificate getTrustedCert()

Returns the most-trusted CA certificate.

Returns:
a trusted X509Certificate or null if the trust anchor was not specified as a trusted certificate

getCA

public final X500Principal getCA()

Returns the name of the most-trusted CA as an X500Principal.

Returns:
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

getCAName

public final String getCAName()

Returns the name of the most-trusted CA in RFC 2253 String format.

Returns:
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

getCAPublicKey

public final PublicKey getCAPublicKey()

Returns the public key of the most-trusted CA.

Returns:
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

getNameConstraints

public final byte[] getNameConstraints()

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 5280 and X.509. The ASN.1 notation for this structure is supplied in the documentation for TrustAnchor(X509Certificate trustedCert, byte[] nameConstraints) .

Note that the byte array returned is cloned to protect against subsequent modifications.

Returns:
a byte array containing the ASN.1 DER encoding of a NameConstraints extension used for checking name constraints, or null if not set.

toString

public String toString()

Returns a formatted string describing the TrustAnchor.

Overrides:
toString in class Object
Returns:
a formatted string describing the TrustAnchor