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MessageDigestSpi

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Summary: Ctors | Methods | Protected Methods | Inherited Methods | [Expand All]

Added in API level 1

public abstract class

MessageDigestSpi

extends Object

java.lang.Object
↳	java.security.MessageDigestSpi

Known Direct Subclasses

MessageDigest

Class Overview

MessageDigestSpi is the Service Provider Interface (SPI) definition for MessageDigest. Examples of digest algorithms are MD5 and SHA. A digest is a secure one way hash function for a stream of bytes. It acts like a fingerprint for a stream of bytes.

See also:

MessageDigest

Summary

Public Constructors
	MessageDigestSpi()

Public Methods
Object	clone() Creates and returns a copy of this `Object`.

Protected Methods
abstract byte[]	engineDigest() Computes and returns the final hash value for this `MessageDigestSpi`.
int	engineDigest(byte[] buf, int offset, int len) Computes and stores the final hash value for this `MessageDigestSpi`.
int	engineGetDigestLength() Returns the engine digest length in bytes.
abstract void	engineReset() Puts this `MessageDigestSpi` back in an initial state, such that it is ready to compute a one way hash value.
abstract void	engineUpdate(byte[] input, int offset, int len) Updates this `MessageDigestSpi` using the given `byte[]`.
abstract void	engineUpdate(byte input) Updates this `MessageDigestSpi` using the given `byte`.
void	engineUpdate(ByteBuffer input) Updates this `MessageDigestSpi` using the given `input`.

[Expand]

Inherited Methods

From class java.lang.Object

Object	clone() Creates and returns a copy of this `Object`.
boolean	equals(Object o) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of `Class` that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait() Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object.
final void	wait(long millis, int nanos) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.
final void	wait(long millis) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.

Public Constructors

public MessageDigestSpi ()

Added in API level 1

Public Methods

public Object clone ()

Added in API level 1

Creates and returns a copy of this Object. The default implementation returns a so-called "shallow" copy: It creates a new instance of the same class and then copies the field values (including object references) from this instance to the new instance. A "deep" copy, in contrast, would also recursively clone nested objects. A subclass that needs to implement this kind of cloning should call super.clone() to create the new instance and then create deep copies of the nested, mutable objects.

Returns
`Object`	a copy of this object.

Throws
`CloneNotSupportedException`

Protected Methods

protected abstract byte[] engineDigest ()

Added in API level 1

Computes and returns the final hash value for this MessageDigestSpi. After the digest is computed the receiver is reset.

Returns
`byte[]`	the computed one way hash value.

See also:

engineReset()

protected int engineDigest (byte[] buf, int offset, int len)

Added in API level 1

Computes and stores the final hash value for this MessageDigestSpi. After the digest is computed the receiver is reset.

Parameters
`buf`	`byte`: the buffer to store the result in.
`offset`	`int`: the index of the first byte in `buf` to store in.
`len`	`int`: the number of bytes allocated for the digest.

Returns
`int`	the number of bytes written to `buf`.

Throws
`DigestException`	if an error occures.
`IllegalArgumentException`	if `offset` or `len` are not valid in respect to `buf`.

See also:

engineReset()

protected int engineGetDigestLength ()

Added in API level 1

Returns the engine digest length in bytes. If the implementation does not implement this function 0 is returned.

Returns
`int`	the digest length in bytes, or `0`.

protected abstract void engineReset ()

Added in API level 1

Puts this MessageDigestSpi back in an initial state, such that it is ready to compute a one way hash value.

protected abstract void engineUpdate (byte[] input, int offset, int len)

Added in API level 1

Updates this MessageDigestSpi using the given byte[].

Parameters
`input`	`byte`: the `byte` array.
`offset`	`int`: the index of the first byte in `input` to update from.
`len`	`int`: the number of bytes in `input` to update from.

Throws
`IllegalArgumentException`	if `offset` or `len` are not valid in respect to `input`.

protected abstract void engineUpdate (byte input)

Added in API level 1

Updates this MessageDigestSpi using the given byte.

Parameters
`input`	`byte`: the `byte` to update this `MessageDigestSpi` with.

See also:

engineReset()

protected void engineUpdate (ByteBuffer input)

Added in API level 1

Updates this MessageDigestSpi using the given input.

Parameters
`input`	`ByteBuffer`: the `ByteBuffer`.

Mar	APR	May
	05
2015	2016	2017

Results

Interfaces

Classes

Enums

Exceptions

MessageDigestSpi

Class Overview

Summary

Public Constructors

public MessageDigestSpi ()

Public Methods

public Object clone ()

Protected Methods

protected abstract byte[] engineDigest ()

protected int engineDigest (byte[] buf, int offset, int len)

protected int engineGetDigestLength ()

protected abstract void engineReset ()

protected abstract void engineUpdate (byte[] input, int offset, int len)

protected abstract void engineUpdate (byte input)

protected void engineUpdate (ByteBuffer input)