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SecretKeySpec

public class SecretKeySpec
extends Object implements KeySpec, SecretKey

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


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.

Summary

Inherited constants

Public constructors

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 methods

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 methods

Public constructors

SecretKeySpec

added in API level 1
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 byte: the key material of the secret key. The contents of the array are copied to protect against subsequent modification.

algorithm String: 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

added in API level 1
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 byte: 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 int: the offset in key where the key material starts.

len int: the length of the key material.

algorithm String: 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

equals

added in API level 1
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 Object: the object to test for equality with this object.

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

getAlgorithm

added in API level 1
public String getAlgorithm ()

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

Returns
String the secret key algorithm.

getEncoded

added in API level 1
public byte[] getEncoded ()

Returns the key material of this secret key.

Returns
byte[] the key material. Returns a new array each time this method is called.

getFormat

added in API level 1
public String getFormat ()

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

Returns
String the string "RAW".

hashCode

added in API level 1
public int hashCode ()

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

Returns
int a hash code value for this object.