Added in API level 1

Summary: Inherited Constants | Ctors | Methods | Inherited Methods

SecretKeySpec

public class SecretKeySpec
extends Object implements KeySpec, SecretKey

java.lang.Object
↳	javax.crypto.spec.SecretKeySpec

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.

See also:

SecretKey
SecretKeyFactory

Summary

Inherited constants

From interface javax.crypto.SecretKey

long

serialVersionUID

The class fingerprint that is set to indicate serialization compatibility since J2SE 1.4.

From interface java.security.Key

long

serialVersionUID

This constant was deprecated in API level 34. A serialVersionUID field in an interface is ineffectual. Do not use; no replacement.

Public constructors
`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.

Public methods
`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.

Inherited methods

From class


        
          java.lang.Object

`Object`	`clone()` Creates and returns a copy of this object.
`boolean`	`equals(Object obj)` Indicates whether some other object is "equal to" this one.
`void`	`finalize()` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
`final Class<?>`	`getClass()` Returns the runtime class of this `Object`.
`int`	`hashCode()` Returns a hash code value for the 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(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.
`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()` Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

From interface


        
          javax.security.auth.Destroyable

`default void`	`destroy()` Destroy this `Object`.
`default boolean`	`isDestroyed()` Determine if this `Object` has been destroyed.

From interface


        
          java.security.Key

`abstract String`	`getAlgorithm()` Returns the standard algorithm name for this key.
`abstract byte[]`	`getEncoded()` Returns the key in its primary encoding format, or null if this key does not support encoding.
`abstract String`	`getFormat()` Returns the name of the primary encoding format of this key, or null if this key does not support encoding.

Public constructors

SecretKeySpec

Added in API level 1

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`	`byte`: 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`	`int`: the offset in `key` where the key material starts.
`len`	`int`: the length of the key material.
`algorithm`	`String`: the name of the secret-key algorithm to be associated with the given key material. See Appendix A in the Java Cryptography Architecture Reference Guide for information about standard algorithm names.

Throws
`IllegalArgumentException`	if `algorithm` is null or `key` is null, empty, or too short, i.e. `key.length-offset<len`.
`ArrayIndexOutOfBoundsException`	is thrown if `offset` or `len` index bytes outside the `key`.

SecretKeySpec

Added in API level 1

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`	`byte`: the key material of the secret key. The contents of the array are copied to protect against subsequent modification.
`algorithm`	`String`: the name of the secret-key algorithm to be associated with the given key material. See Appendix A in the Java Cryptography Architecture Reference Guide for information about standard algorithm names.

Throws
`IllegalArgumentException`	if `algorithm` is null or `key` is null or empty.

Public methods

equals

Added in API level 1

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.

Parameters
`obj`	`Object`: the object to test for equality with this object.

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

getAlgorithm

Added in API level 1

public String getAlgorithm ()

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

Returns
`String`	the secret key algorithm.

getEncoded

Added in API level 1

public byte[] getEncoded ()

Returns the key material of this secret key.

Returns
`byte[]`	the key material. Returns a new array each time this method is called.

getFormat

Added in API level 1

public String getFormat ()

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

Returns
`String`	the string "RAW".

hashCode

Added in API level 1

public int hashCode ()

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

Returns
`int`	a hash code value for this object.