程序包 javax.crypto.spec

类 DESKeySpec

java.lang.Object

javax.crypto.spec.DESKeySpec

所有已实现的接口:

KeySpec

public class DESKeySpec
extends Object
implements KeySpec

This class specifies a DES key.

从以下版本开始:

1.4

字段概要

字段

限定符和类型	字段	说明
static int	DES_KEY_LEN	The constant which defines the length of a DES key in bytes.

构造器概要

构造器

构造器	说明
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.

方法概要

限定符和类型	方法	说明
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.

从类继承的方法 java.lang.Object

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

字段详细资料

DES_KEY_LEN

public static final int DES_KEY_LEN

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

另请参阅:

常量字段值

构造器详细资料

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.

参数:

key - the buffer with the DES key material. The first 8 bytes of the buffer are copied to protect against subsequent modification.

抛出:

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.

参数:

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.

抛出:

NullPointerException - if the given key material is null

InvalidKeyException - if the given key material, starting at offset inclusive, is shorter than 8 bytes.

方法详细资料

getKey

public byte[] getKey()

Returns the DES key material.

返回:

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.

参数:

key - the buffer with the DES key material.

offset - the offset in key, where the DES key material starts.

返回:

true if the given DES key material is parity-adjusted, false otherwise.

抛出:

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.

参数:

key - the buffer with the DES key material.

offset - the offset in key, where the DES key material starts.

返回:

true if the given DES key material is weak or semi-weak, false otherwise.

抛出:

InvalidKeyException - if the given key material is null, or starting at offset inclusive, is shorter than 8 bytes.