javax.crypto.spec
Class SecretKeySpec

java.lang.Object
  |
  +--javax.crypto.spec.SecretKeySpec

All Implemented Interfaces:

Key, KeySpec

public class SecretKeySpec

extends Object

implements KeySpec, Key

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

It can be used to construct a SecretKey from a byte array.

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.

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.

Method Summary

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.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

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 must 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.

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