Class DESKeySpec

java.lang.Object

javax.crypto.spec.DESKeySpec

All Implemented Interfaces:: KeySpec

public class DESKeySpec extends Object implements KeySpec

This class specifies a DES key.

Since:: 1.4

Field Summary

Modifier and Type	Field	Description
`static final int`	`DES_KEY_LEN`	The constant which defines the length of a DES key in bytes.

Constructor Summary

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.

Method Summary

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 Object

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

Modifier and Type	Method	Description
`protected Object`	`clone()`	Creates and returns a copy of this object.
`boolean`	`equals(Object obj)`	Indicates whether some other object is "equal to" this one.
`protected void`	`finalize()`	Deprecated, for removal: This API element is subject to removal in a future version. Finalization is deprecated and subject to removal in a future release.
`final Class<?>`	`getClass()`	Returns the runtime class of this `Object`.
`int`	`hashCode()`	Returns a hash code value for this object.
`final void`	`notify()`	Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()`	Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()`	Returns a string representation of the object.
`final void`	`wait()`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
`final void`	`wait(long timeoutMillis)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis, int nanos)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

Field Details

DES_KEY_LEN

public static final int DES_KEY_LEN

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

See Also:

Constructor Details

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.; ArrayIndexOutOfBoundsException - if offset is negative.

Method Details

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.; ArrayIndexOutOfBoundsException - if offset is negative.

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.; ArrayIndexOutOfBoundsException - if offset is negative.

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