javax.crypto.spec
Class SecretKeySpec

java.lang.Object
 extended by 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.

Since:

1.4

See Also:

SecretKey, SecretKeyFactory, Serialized Form

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. 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.

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) 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.

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

public String getAlgorithm()

public String getFormat()

public byte[] getEncoded()

public int hashCode()

public boolean equals(Object obj)