DESKeySpec
public class DESKeySpec
extends Object
implements KeySpec
java.lang.Object | |
↳ | javax.crypto.spec.DESKeySpec |
This class specifies a DES key.
Summary
Constants | |
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int | DES_KEY_LEN The constant which defines the length of a DES key in bytes. |
Public constructors | |
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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 | |
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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 | |
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key | byte : the buffer with the DES key material. The first 8 bytes of the buffer are copied to protect against subsequent modification. |
Throws | |
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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 | |
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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 | |
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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 | |
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InvalidKeyException | if the given key material is null , or starting at offset inclusive, is shorter than 8 bytes. |