Class KerberosKey

This class encapsulates a long term secret key for a Kerberos principal.

All Kerberos JAAS login modules that obtain a principal's password and generate the secret key from it should use this class. Sometimes, such as when authenticating a server in the absence of user-to-user authentication, the login module will store an instance of this class in the private credential set of a Subject during the commit phase of the authentication process.

A Kerberos service using a keytab to read secret keys should use the KeyTab class, where latest keys can be read when needed.

It might be necessary for the application to be granted a PrivateCredentialPermission if it needs to access the KerberosKey instance from a Subject. This permission is not needed when the application depends on the default JGSS Kerberos mechanism to access the KerberosKey. In that case, however, the application will need an appropriate ServicePermission.

Constructors

KerberosKey

public KerberosKey(KerberosPrincipal principal,
                   byte[] keyBytes,
                   int keyType,
                   int versionNum)

Constructs a KerberosKey from the given bytes when the key type and key version number are known. This can be used when reading the secret key information from a Kerberos "keytab".

Parameters:

principal - the principal that this secret key belongs to

keyBytes - the raw bytes for the secret key

keyType - the key type for the secret key as defined by the Kerberos protocol specification.

versionNum - the version number of this secret key

KerberosKey

public KerberosKey(KerberosPrincipal principal,
                   char[] password,
                   String algorithm)

Constructs a KerberosKey from a principal's password.

Parameters:

principal - the principal that this password belongs to

password - the password that should be used to compute the key

algorithm - the name for the algorithm that this key will be used for. This parameter may be null in which case the default algorithm "DES" will be assumed.

Throws:

IllegalArgumentException - if the name of the algorithm passed is unsupported.

Methods

getPrincipal

public final KerberosPrincipal getPrincipal()

Returns the principal that this key belongs to.

Returns:

the principal this key belongs to.

getVersionNumber

public final int getVersionNumber()

Returns the key version number.

Returns:

the key version number.

getKeyType

public final int getKeyType()

Returns the key type for this long-term key.

Returns:

the key type.

getAlgorithm

public final String getAlgorithm()

Returns the standard algorithm name for this key. For example, "DES" would indicate that this key is a DES key. See Appendix A in the Java Cryptography Architecture API Specification & Reference for information about standard algorithm names.

Specified by:

getAlgorithm in interface Key

Returns:

the name of the algorithm associated with this key.

getFormat

public final String getFormat()

Returns the name of the encoding format for this secret key.

Specified by:

getFormat in interface Key

Returns:

the String "RAW"

getEncoded

public final byte[] getEncoded()

Returns the key material of this secret key.

Specified by:

getEncoded in interface Key

Returns:

the key material

destroy

public void destroy()
             throws DestroyFailedException

Destroys this key. A call to any of its other methods after this will cause an IllegalStateException to be thrown.

Specified by:

destroy in interface Destroyable

Throws:

DestroyFailedException - if some error occurs while destorying this key.

isDestroyed

public boolean isDestroyed()

Determines if this key has been destroyed.

Specified by:

isDestroyed in interface Destroyable

Returns:

true if this Object has been destroyed, false otherwise.

toString

public String toString()

Description copied from class: Object

getClass().getName() + '@' + Integer.toHexString(hashCode())

Overrides:

toString in class Object

Returns:

a string representation of the object.

hashCode

public int hashCode()

Returns a hashcode for this KerberosKey.

Overrides:

hashCode in class Object

Returns:

a hashCode() for the KerberosKey

Since:

1.6

See Also:

Object.equals(java.lang.Object), System.identityHashCode(java.lang.Object)

equals

public boolean equals(Object other)

Compares the specified Object with this KerberosKey for equality. Returns true if the given object is also a KerberosKey and the two KerberosKey instances are equivalent.

Overrides:

equals in class Object

Parameters:

other - the Object to compare to

Returns:

true if the specified object is equal to this KerberosKey, false otherwise. NOTE: Returns false if either of the KerberosKey objects has been destroyed.

Since:

1.6

See Also:

Object.hashCode(), HashMap