Class DESKeySpec

All Implemented Interfaces:
KeySpec
public class DESKeySpec
extends Object
implements KeySpec

This class specifies a DES key.

Since:
1.4

Fields

Modifier and Type Field Description
static int DES_KEY_LEN

The constant which defines the length of a DES key in bytes.

Constructors

Constructor Description
DESKeySpec​(byte[] key)

Creates a DESKeySpec object using the first 8 bytes in key as the key material for the DES key.
DESKeySpec​(byte[] key, int offset)

Creates a DESKeySpec object using the first 8 bytes in key, beginning at offset inclusive, as the key material for the DES key.

Methods

Modifier and Type Method Description
byte[] getKey()

Returns the DES key material.
static boolean isParityAdjusted​(byte[] key, int offset)

Checks if the given DES key material, starting at offset inclusive, is parity-adjusted.
static boolean isWeak​(byte[] key, int offset)

Checks if the given DES key material is weak or semi-weak.

Methods declared in class java.lang.Object

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

Fields

DES_KEY_LEN

public static final int DES_KEY_LEN

The constant which defines the length of a DES key in bytes.

See Also:
Constant Field Values

Constructors

DESKeySpec

public DESKeySpec(byte[] key)
           throws InvalidKeyException

Creates a DESKeySpec object using the first 8 bytes in key as the key material for the DES key.

The bytes that constitute the DES key are those between key[0] and key[7] inclusive.

Parameters:
key - the buffer with the DES key material. The first 8 bytes of the buffer are copied to protect against subsequent modification.
Throws:
NullPointerException - if the given key material is null
InvalidKeyException - if the given key material is shorter than 8 bytes.

DESKeySpec

public DESKeySpec(byte[] key,
                  int offset)
           throws InvalidKeyException

Creates a DESKeySpec object using the first 8 bytes in key, beginning at offset inclusive, as the key material for the DES key.

The bytes that constitute the DES key are those between key[offset] and key[offset+7] inclusive.

Parameters:
key - the buffer with the DES key material. The first 8 bytes of the buffer beginning at offset inclusive are copied to protect against subsequent modification.
offset - the offset in key, where the DES key material starts.
Throws:
NullPointerException - if the given key material is null
InvalidKeyException - if the given key material, starting at offset inclusive, is shorter than 8 bytes.

Methods

getKey

public byte[] getKey()

Returns the DES key material.

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

isParityAdjusted

public static boolean isParityAdjusted(byte[] key,
                                       int offset)
                                throws InvalidKeyException

Checks if the given DES key material, starting at offset inclusive, is parity-adjusted.

Parameters:
key - the buffer with the DES key material.
offset - the offset in key, where the DES key material starts.
Returns:
true if the given DES key material is parity-adjusted, false otherwise.
Throws:
InvalidKeyException - if the given key material is null, or starting at offset inclusive, is shorter than 8 bytes.

isWeak

public static boolean isWeak(byte[] key,
                             int offset)
                      throws InvalidKeyException

Checks if the given DES key material is weak or semi-weak.

Parameters:
key - the buffer with the DES key material.
offset - the offset in key, where the DES key material starts.
Returns:
true if the given DES key material is weak or semi-weak, false otherwise.
Throws:
InvalidKeyException - if the given key material is null, or starting at offset inclusive, is shorter than 8 bytes.

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https://docs.oracle.com/en/java/javase/11/docs/api/java.base/javax/crypto/spec/DESKeySpec.html