SecretKeySpec

public class SecretKeySpec extends Object
implements KeySpec SecretKey

This class specifies a secret key in a provider-independent fashion.

It can be used to construct a SecretKey from a byte array, without having to go through a (provider-based) SecretKeyFactory.

This class is only useful for raw secret keys that can be represented as a byte array and have no key parameters associated with them, e.g., DES or Triple DES keys.

See Also

• SecretKey
• SecretKeyFactory

Inherited Constant Summary

From interface javax.crypto.SecretKey

long

serialVersionUID

The class fingerprint that is set to indicate serialization compatibility since J2SE 1.4.

From interface java.security.Key

long

serialVersionUID

The class fingerprint that is set to indicate serialization compatibility with a previous version of the class.

Public Constructor Summary

	SecretKeySpec(byte[] key, String algorithm) Constructs a secret key from the given byte array.
	SecretKeySpec(byte[] key, int offset, int len, String algorithm) Constructs a secret key from the given byte array, using the first len bytes of key, starting at offset inclusive.

Public Method Summary

boolean	equals(Object obj) Tests for equality between the specified object and this object.
String	getAlgorithm() Returns the name of the algorithm associated with this secret key.
byte[]	getEncoded() Returns the key material of this secret key.
String	getFormat() Returns the name of the encoding format for this secret key.
int	hashCode() Calculates a hash code value for the object.

Inherited Method Summary

From class java.lang.Object

Object	clone() Creates and returns a copy of this Object.
boolean	equals(Object obj) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of Class that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait(long timeout, int nanos) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait(long timeout) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait() Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object.

From interface java.security.Key

abstract String	getAlgorithm() Returns the standard algorithm name for this key.
abstract byte[]	getEncoded() Returns the key in its primary encoding format, or null if this key does not support encoding.
abstract String	getFormat() Returns the name of the primary encoding format of this key, or null if this key does not support encoding.

From interface javax.security.auth.Destroyable

void	destroy() Destroy this Object.
boolean	isDestroyed() Determine if this Object has been destroyed.

Public Constructors

public SecretKeySpec (byte[] key, String algorithm)

Constructs a secret key from the given byte array.

This constructor does not check if the given bytes indeed specify a secret key of the specified algorithm. For example, if the algorithm is DES, this constructor does not check if key is 8 bytes long, and also does not check for weak or semi-weak keys. In order for those checks to be performed, an algorithm-specific key specification class (in this case: DESKeySpec) should be used.

Parameters

key	the key material of the secret key. The contents of the array are copied to protect against subsequent modification.
algorithm	the name of the secret-key algorithm to be associated with the given key material. See Appendix A in the Java Cryptography Architecture Reference Guide for information about standard algorithm names.

Throws

IllegalArgumentException	if algorithm is null or key is null or empty.

public SecretKeySpec (byte[] key, int offset, int len, String algorithm)

Constructs a secret key from the given byte array, using the first len bytes of key, starting at offset inclusive.

The bytes that constitute the secret key are those between key[offset] and key[offset+len-1] inclusive.

This constructor does not check if the given bytes indeed specify a secret key of the specified algorithm. For example, if the algorithm is DES, this constructor does not check if key is 8 bytes long, and also does not check for weak or semi-weak keys. In order for those checks to be performed, an algorithm-specific key specification class (in this case: DESKeySpec) must be used.

Parameters

key	the key material of the secret key. The first len bytes of the array beginning at offset inclusive are copied to protect against subsequent modification.
offset	the offset in key where the key material starts.
len	the length of the key material.
algorithm	the name of the secret-key algorithm to be associated with the given key material. See Appendix A in the Java Cryptography Architecture Reference Guide for information about standard algorithm names.

Throws

IllegalArgumentException	if algorithm is null or key is null, empty, or too short, i.e. key.length-offset<len.
ArrayIndexOutOfBoundsException	is thrown if offset or len index bytes outside the key.

Public Methods

public boolean equals (Object obj)

Tests for equality between the specified object and this object. Two SecretKeySpec objects are considered equal if they are both SecretKey instances which have the same case-insensitive algorithm name and key encoding.

Parameters

obj	the object to test for equality with this object.

Returns

• true if the objects are considered equal, false if obj is null or otherwise.

public String getAlgorithm ()

Returns the name of the algorithm associated with this secret key.

Returns

• the secret key algorithm.

public byte[] getEncoded ()

Returns the key material of this secret key.

Returns

• the key material. Returns a new array each time this method is called.

public String getFormat ()

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

Returns

• the string "RAW".

public int hashCode ()

Calculates a hash code value for the object. Objects that are equal will also have the same hashcode.

Returns

• this object's hash code.