javax.crypto.spec
Class SecretKeySpec

java.lang.Object
  javax.crypto.spec.SecretKeySpec

All Implemented Interfaces:

Serializable, Key, KeySpec, SecretKey

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.

Version:

$Id: SecretKeySpec.java 1913 2007-08-08 02:41:53Z jpeters $

Author:

Patric Kabus, Jan Peters

See Also:

Serialized Form

Field Summary

private String	algorithm_ The name of the secret-key algorithm.
private byte[]	key_ The key material of the secret key.

Fields inherited from interface java.security.Key

serialVersionUID

Constructor Summary

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.

SecretKeySpec(byte[] key, String algorithm)
Constructs a secret key from the given byte array.

Method Summary

boolean	equals(Object obj) Calculates a hash code value for the 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.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Field Detail

algorithm_

private String algorithm_

The name of the secret-key algorithm.

key_

private byte[] key_

The key material of the secret key.

Constructor Detail

SecretKeySpec

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.

algorithm - the name of the secret-key algorithm to be associated with the given key material. See Appendix A in the Java Cryptography Extension Reference Guide for information about standard algorithm names.

Throws:

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

SecretKeySpec

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) should be used.

Parameters:

key - the key material of the secret key.

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 Extension Reference Guide for information about standard algorithm names.

Throws:

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

ArrayIndexOutOfBoundsException - - is thrown if offset or len index bytes outside the key .

Method Detail

getAlgorithm

public String getAlgorithm()

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

Specified by:

getAlgorithm in interface Key

Returns:

the secret key algorithm.

getFormat

public 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 byte[] getEncoded()

Returns the key material of this secret key.

Specified by:

getEncoded in interface Key

Returns:

the key material.

hashCode

public int hashCode()

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

Overrides:

hashCode in class Object

Returns:

a hash code value for this object.

See Also:

Object#hashCode Object.hasCode()}, {@link Hashtable}

equals

public boolean equals(Object obj)

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

Overrides:

equals in class Object

Parameters:

obj - the reference object with which to compare.

Returns:

true if this object is the same as the obj argument; false otherwise.

See Also:

Object#equals() Object.equals(java.lang.Object)}, {@link Hashtable}