Class SecretKeySpec

java.lang.Object

javax.crypto.spec.SecretKeySpec

All Implemented Interfaces:: Serializable, Key, KeySpec, SecretKey, Destroyable

public class SecretKeySpec extends Object implements KeySpec, SecretKey

This class specifies a secret key in a provider-independent fashion.

It can be used to construct a SecretKey from a byte array, without having to go through a (provider-based) SecretKeyFactory.

This class is only useful for raw secret keys that can be represented as a byte array and have no key parameters associated with them, e.g., DES or Triple DES keys.

Since:

1.4

See Also:

Constructor Summary

Constructor	Description
`SecretKeySpec(byte[] key, int offset, int len, String algorithm)`	Constructs a secret key from the given byte array, using the first `len` bytes of `key`, starting at `offset` inclusive.
`SecretKeySpec(byte[] key, String algorithm)`	Constructs a secret key from the given byte array.

Method Summary

Modifier and Type	Method	Description
`boolean`	`equals(Object obj)`	Tests for equality between the specified object and this object.
`String`	`getAlgorithm()`	Returns the name of the algorithm associated with this secret key.
`byte[]`	`getEncoded()`	Returns the key material of this secret key.
`String`	`getFormat()`	Returns the name of the encoding format for this secret key.
`int`	`hashCode()`	Calculates a hash code value for the object.

Methods declared in class Object

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

Modifier and Type	Method	Description
`protected Object`	`clone()`	Creates and returns a copy of this object.
`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`.
`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.

Methods declared in interface Destroyable

destroy, isDestroyed

Modifier and Type	Method	Description
`default void`	`destroy()`	Destroy this `Object`.
`default boolean`	`isDestroyed()`	Determine if this `Object` has been destroyed.

Constructor Details

SecretKeySpec

public SecretKeySpec(byte[] key, String algorithm)

Constructs a secret key from the given byte array.

This constructor does not check if the given bytes indeed specify a secret key of the specified algorithm. For example, if the algorithm is DES, this constructor does not check if key is 8 bytes long, and also does not check for weak or semi-weak keys. In order for those checks to be performed, an algorithm-specific key specification class (in this case: DESKeySpec) should be used.

Parameters:

key - the key material of the secret key. The contents of the array are copied to protect against subsequent modification.

algorithm - the name of the secret key algorithm to be associated with the given key material. See the SecretKey Algorithms section in the Java Security Standard Algorithm Names Specification for information about standard secret key algorithm names.

Throws:

IllegalArgumentException - if algorithm is null or key is null or empty.

External Specifications

SecretKeySpec

public SecretKeySpec(byte[] key, int offset, int len, String algorithm)

Constructs a secret key from the given byte array, using the first len bytes of key, starting at offset inclusive.

The bytes that constitute the secret key are those between key[offset] and key[offset+len-1] inclusive.

This constructor does not check if the given bytes indeed specify a secret key of the specified algorithm. For example, if the algorithm is DES, this constructor does not check if key is 8 bytes long, and also does not check for weak or semi-weak keys. In order for those checks to be performed, an algorithm-specific key specification class (in this case: DESKeySpec) must be used.

Parameters:

key - the key material of the secret key. The first len bytes of the array beginning at offset inclusive are copied to protect against subsequent modification.

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

len - the length of the key material.

Throws:

IllegalArgumentException - if algorithm is null or key is null, empty, or too short, i.e. key.length-offset<len.

ArrayIndexOutOfBoundsException - if offset or len are negative.

External Specifications

Method Details

getAlgorithm

public String getAlgorithm()

Returns the name of the algorithm associated with this secret key.

Specified by:

getAlgorithm in interface Key

Returns:

the secret key algorithm.

External Specifications

getFormat

public String getFormat()

Returns the name of the encoding format for this secret key.

Specified by:: getFormat in interface Key
Returns:: the string "RAW".

getEncoded

public byte[] getEncoded()

Returns the key material of this secret key.

Specified by:: getEncoded in interface Key
Returns:: the key material. Returns a new array each time this method is called.

hashCode

public int hashCode()

Calculates a hash code value for the object. Objects that are equal will also have the same hashcode.

Overrides:

hashCode in class Object

Returns:

a hash code value for this object

See Also:

equals

public boolean equals(Object obj)

Tests for equality between the specified object and this object. Two SecretKeySpec objects are considered equal if they are both SecretKey instances which have the same case-insensitive algorithm name and key encoding.

Overrides:

equals in class Object

Parameters:

obj - the object to test for equality with this object.

Returns:

true if the objects are considered equal, false if obj is null or otherwise.

See Also:

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