Blake2bDigest (Bouncy Castle Library 1.60 API Specification)

java.lang.Object
- org.bouncycastle.crypto.digests.Blake2bDigest

All Implemented Interfaces:

Digest, ExtendedDigest
```
public class Blake2bDigest
extends java.lang.Object
implements ExtendedDigest
```
Implementation of the cryptographic hash function Blakbe2b.
Blake2b offers a built-in keying mechanism to be used directly for authentication ("Prefix-MAC") rather than a HMAC construction.
Blake2b offers a built-in support for a salt for randomized hashing and a personal string for defining a unique hash function for each application.
BLAKE2b is optimized for 64-bit platforms and produces digests of any size between 1 and 64 bytes.

Constructor Summary

Constructors
Constructor	Description
`Blake2bDigest()`
`Blake2bDigest(byte[] key)`	Blake2b for authentication ("Prefix-MAC mode").
`Blake2bDigest(byte[] key, int digestLength, byte[] salt, byte[] personalization)`	Blake2b with key, required digest length (in bytes), salt and personalization.
`Blake2bDigest(int digestSize)`	Basic sized constructor - size in bits.
`Blake2bDigest(Blake2bDigest digest)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`clearKey()`	Overwrite the key if it is no longer used (zeroization)
`void`	`clearSalt()`	Overwrite the salt (pepper) if it is secret and no longer used (zeroization)
`int`	`doFinal(byte[] out, int outOffset)`	close the digest, producing the final digest value.
`java.lang.String`	`getAlgorithmName()`	return the algorithm name
`int`	`getByteLength()`	Return the size in bytes of the internal buffer the digest applies it's compression function to.
`int`	`getDigestSize()`	return the size, in bytes, of the digest produced by this message digest.
`void`	`reset()`	Reset the digest back to it's initial state.
`void`	`update(byte b)`	update the message digest with a single byte.
`void`	`update(byte[] message, int offset, int len)`	update the message digest with a block of bytes.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - Blake2bDigest
```
public Blake2bDigest()
```
  - Blake2bDigest
```
public Blake2bDigest(Blake2bDigest digest)
```
  - Blake2bDigest
```
public Blake2bDigest(int digestSize)
```
    Basic sized constructor - size in bits.
    
    Parameters:
    
    digestSize - size of the digest in bits
  - Blake2bDigest
```
public Blake2bDigest(byte[] key)
```
    Blake2b for authentication ("Prefix-MAC mode"). After calling the doFinal() method, the key will remain to be used for further computations of this instance. The key can be overwritten using the clearKey() method.
    
    Parameters:
    
    key - A key up to 64 bytes or null
  - Blake2bDigest
```
public Blake2bDigest(byte[] key,
                     int digestLength,
                     byte[] salt,
                     byte[] personalization)
```
    Blake2b with key, required digest length (in bytes), salt and personalization. After calling the doFinal() method, the key, the salt and the personal string will remain and might be used for further computations with this instance. The key can be overwritten using the clearKey() method, the salt (pepper) can be overwritten using the clearSalt() method.
    
    Parameters:
    
    key - A key up to 64 bytes or null
    
    digestLength - from 1 up to 64 bytes
    
    salt - 16 bytes or null
    
    personalization - 16 bytes or null
- Method Detail
  - update
```
public void update(byte b)
```
    update the message digest with a single byte.
    
    Specified by:
    
    update in interface Digest
    
    Parameters:
    
    b - the input byte to be entered.
  - update
```
public void update(byte[] message,
                   int offset,
                   int len)
```
    update the message digest with a block of bytes.
    
    Specified by:
    
    update in interface Digest
    
    Parameters:
    
    message - the byte array containing the data.
    
    offset - the offset into the byte array where the data starts.
    
    len - the length of the data.
  - doFinal
```
public int doFinal(byte[] out,
                   int outOffset)
```
    close the digest, producing the final digest value. The doFinal call leaves the digest reset. Key, salt and personal string remain.
    
    Specified by:
    
    doFinal in interface Digest
    
    Parameters:
    
    out - the array the digest is to be copied into.
    
    outOffset - the offset into the out array the digest is to start at.
  - reset
```
public void reset()
```
    Reset the digest back to it's initial state. The key, the salt and the personal string will remain for further computations.
    
    Specified by:
    
    reset in interface Digest
  - getAlgorithmName
```
public java.lang.String getAlgorithmName()
```
    return the algorithm name
    
    Specified by:
    
    getAlgorithmName in interface Digest
    
    Returns:
    
    the algorithm name
  - getDigestSize
```
public int getDigestSize()
```
    return the size, in bytes, of the digest produced by this message digest.
    
    Specified by:
    
    getDigestSize in interface Digest
    
    Returns:
    
    the size, in bytes, of the digest produced by this message digest.
  - getByteLength
```
public int getByteLength()
```
    Return the size in bytes of the internal buffer the digest applies it's compression function to.
    
    Specified by:
    
    getByteLength in interface ExtendedDigest
    
    Returns:
    
    byte length of the digests internal buffer.
  - clearKey
```
public void clearKey()
```
    Overwrite the key if it is no longer used (zeroization)
  - clearSalt
```
public void clearSalt()
```
    Overwrite the salt (pepper) if it is secret and no longer used (zeroization)

Class Blake2bDigest

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

Blake2bDigest

Blake2bDigest

Blake2bDigest

Blake2bDigest

Blake2bDigest

Method Detail

update

update

doFinal

reset

getAlgorithmName

getDigestSize

getByteLength

clearKey

clearSalt