DESKeySpec
public
class
DESKeySpec
extends Object
implements
KeySpec
java.lang.Object | |
↳ | javax.crypto.spec.DESKeySpec |
This class specifies a DES key.
Summary
Constants | |
---|---|
int |
DES_KEY_LEN
The constant which defines the length of a DES key in bytes. |
Public constructors | |
---|---|
DESKeySpec(byte[] key)
Creates a DESKeySpec object using the first 8 bytes in
|
|
DESKeySpec(byte[] key, int offset)
Creates a DESKeySpec object using the first 8 bytes in
|
Public methods | |
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byte[]
|
getKey()
Returns the DES key material. |
static
boolean
|
isParityAdjusted(byte[] key, int offset)
Checks if the given DES key material, starting at |
static
boolean
|
isWeak(byte[] key, int offset)
Checks if the given DES key material is weak or semi-weak. |
Inherited methods | |
---|---|
Constants
DES_KEY_LEN
public static final int DES_KEY_LEN
The constant which defines the length of a DES key in bytes.
Constant Value: 8 (0x00000008)
Public constructors
DESKeySpec
public DESKeySpec (byte[] key)
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 |
byte : 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)
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 |
byte : 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 |
int : 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. |
Public methods
getKey
public byte[] getKey ()
Returns the DES key material.
Returns | |
---|---|
byte[] |
the DES key material. Returns a new array each time this method is called. |
isParityAdjusted
public static boolean isParityAdjusted (byte[] key, int offset)
Checks if the given DES key material, starting at offset
inclusive, is parity-adjusted.
Parameters | |
---|---|
key |
byte : the buffer with the DES key material. |
offset |
int : the offset in key , where the DES key
material starts. |
Returns | |
---|---|
boolean |
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)
Checks if the given DES key material is weak or semi-weak.
Parameters | |
---|---|
key |
byte : the buffer with the DES key material. |
offset |
int : the offset in key , where the DES key
material starts. |
Returns | |
---|---|
boolean |
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. |