GCMBlockCipher (Bouncy Castle Library (LTS Edition) 2.73.5 Provider API)

java.lang.Object
- org.bouncycastle.crypto.modes.GCMBlockCipher

All Implemented Interfaces:

AEADBlockCipher, AEADCipher, GCMModeCipher
```
public class GCMBlockCipher
extends java.lang.Object
implements GCMModeCipher
```
Implements the Galois/Counter mode (GCM) detailed in NIST Special Publication 800-38D.

Constructor Summary

Constructors
Constructor and Description

GCMBlockCipher(BlockCipher c)

GCMBlockCipher(BlockCipher c, GCMMultiplier m)

Constructors
Constructor and Description
`GCMBlockCipher(BlockCipher c)`
`GCMBlockCipher(BlockCipher c, GCMMultiplier m)`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`int`	`doFinal(byte[] out, int outOff)` Finish the operation either appending or verifying the MAC at the end of the data.
`java.lang.String`	`getAlgorithmName()` Return the name of the algorithm.
`byte[]`	`getMac()` Return the value of the MAC associated with the last stream processed.
`int`	`getOutputSize(int len)` return the size of the output buffer required for a processBytes plus a doFinal with an input of len bytes.
`BlockCipher`	`getUnderlyingCipher()` return the `BlockCipher` this object wraps.
`int`	`getUpdateOutputSize(int len)` return the size of the output buffer required for a processBytes an input of len bytes.
`void`	`init(boolean forEncryption, CipherParameters params)` NOTE: MAC sizes from 32 bits to 128 bits (must be a multiple of 8) are supported.
`static GCMModeCipher`	`newInstance(BlockCipher cipher)` Return a new GCM mode cipher based on the passed in base cipher
`static GCMModeCipher`	`newInstance(BlockCipher cipher, GCMMultiplier m)` Return a new GCM mode cipher based on the passed in base cipher and multiplier.
`void`	`processAADByte(byte in)` Add a single byte to the associated data check.
`void`	`processAADBytes(byte[] in, int inOff, int len)` Add a sequence of bytes to the associated data check.
`int`	`processByte(byte in, byte[] out, int outOff)` encrypt/decrypt a single byte.
`int`	`processBytes(byte[] in, int inOff, int len, byte[] out, int outOff)` process a block of bytes from in putting the result into out.
`void`	`reset()` Reset the cipher.
`java.lang.String`	`toString()`

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

- Constructor Detail
  - GCMBlockCipher
```
public GCMBlockCipher(BlockCipher c)
```
  - GCMBlockCipher
```
public GCMBlockCipher(BlockCipher c,
                      GCMMultiplier m)
```
- Method Detail
  - newInstance
```
public static GCMModeCipher newInstance(BlockCipher cipher)
```
    Return a new GCM mode cipher based on the passed in base cipher
    
    Parameters:
    
    cipher - the base cipher for the GCM mode.
  - newInstance
```
public static GCMModeCipher newInstance(BlockCipher cipher,
                                        GCMMultiplier m)
```
    Return a new GCM mode cipher based on the passed in base cipher and multiplier.
    
    Parameters:
    
    cipher - the base cipher for the GCM mode.
    
    m - the GCM multiplier to use.
  - getUnderlyingCipher
```
public BlockCipher getUnderlyingCipher()
```
    Description copied from interface: AEADBlockCipher
    
    return the BlockCipher this object wraps.
    
    Specified by:
    
    getUnderlyingCipher in interface AEADBlockCipher
    
    Returns:
    
    the BlockCipher this object wraps.
  - getAlgorithmName
```
public java.lang.String getAlgorithmName()
```
    Description copied from interface: AEADCipher
    
    Return the name of the algorithm.
    
    Specified by:
    
    getAlgorithmName in interface AEADCipher
    
    Returns:
    
    the algorithm name.
  - init
```
public void init(boolean forEncryption,
                 CipherParameters params)
          throws java.lang.IllegalArgumentException
```
    NOTE: MAC sizes from 32 bits to 128 bits (must be a multiple of 8) are supported. The default is 128 bits. Sizes less than 96 are not recommended, but are supported for specialized applications.
    
    Specified by:
    
    init in interface AEADCipher
    
    Parameters:
    
    forEncryption - true if we are setting up for encryption, false otherwise.
    
    params - the necessary parameters for the underlying cipher to be initialised.
    
    Throws:
    
    java.lang.IllegalArgumentException - if the params argument is inappropriate.
  - getMac
```
public byte[] getMac()
```
    Description copied from interface: AEADCipher
    
    Return the value of the MAC associated with the last stream processed.
    
    Specified by:
    
    getMac in interface AEADCipher
    
    Returns:
    
    MAC for plaintext data.
  - getOutputSize
```
public int getOutputSize(int len)
```
    Description copied from interface: AEADCipher
    
    return the size of the output buffer required for a processBytes plus a doFinal with an input of len bytes.
    The returned size may be dependent on the initialisation of this cipher and may not be accurate once subsequent input data is processed - this method should be invoked immediately prior to a call to final processing of input data and a call to AEADCipher.doFinal(byte[], int).
    
    Specified by:
    
    getOutputSize in interface AEADCipher
    
    Parameters:
    
    len - the length of the input.
    
    Returns:
    
    the space required to accommodate a call to processBytes and doFinal with len bytes of input.
  - getUpdateOutputSize
```
public int getUpdateOutputSize(int len)
```
    Description copied from interface: AEADCipher
    
    return the size of the output buffer required for a processBytes an input of len bytes.
    The returned size may be dependent on the initialisation of this cipher and may not be accurate once subsequent input data is processed - this method should be invoked immediately prior to input data being processed.
    
    Specified by:
    
    getUpdateOutputSize in interface AEADCipher
    
    Parameters:
    
    len - the length of the input.
    
    Returns:
    
    the space required to accommodate a call to processBytes with len bytes of input.
  - processAADByte
```
public void processAADByte(byte in)
```
    Description copied from interface: AEADCipher
    
    Add a single byte to the associated data check.
    If the implementation supports it, this will be an online operation and will not retain the associated data.
    
    Specified by:
    
    processAADByte in interface AEADCipher
    
    Parameters:
    
    in - the byte to be processed.
  - processAADBytes
```
public void processAADBytes(byte[] in,
                            int inOff,
                            int len)
```
    Description copied from interface: AEADCipher
    
    Add a sequence of bytes to the associated data check.
    If the implementation supports it, this will be an online operation and will not retain the associated data.
    
    Specified by:
    
    processAADBytes in interface AEADCipher
    
    Parameters:
    
    in - the input byte array.
    
    inOff - the offset into the in array where the data to be processed starts.
    
    len - the number of bytes to be processed.
  - processByte
```
public int processByte(byte in,
                       byte[] out,
                       int outOff)
                throws DataLengthException
```
    Description copied from interface: AEADCipher
    
    encrypt/decrypt a single byte.
    
    Specified by:
    
    processByte in interface AEADCipher
    
    Parameters:
    
    in - the byte to be processed.
    
    out - the output buffer the processed byte goes into.
    
    outOff - the offset into the output byte array the processed data starts at.
    
    Returns:
    
    the number of bytes written to out.
    
    Throws:
    
    DataLengthException - if the output buffer is too small.
  - processBytes
```
public int processBytes(byte[] in,
                        int inOff,
                        int len,
                        byte[] out,
                        int outOff)
                 throws DataLengthException
```
    Description copied from interface: AEADCipher
    
    process a block of bytes from in putting the result into out.
    
    Specified by:
    
    processBytes in interface AEADCipher
    
    Parameters:
    
    in - the input byte array.
    
    inOff - the offset into the in array where the data to be processed starts.
    
    len - the number of bytes to be processed.
    
    out - the output buffer the processed bytes go into.
    
    outOff - the offset into the output byte array the processed data starts at.
    
    Returns:
    
    the number of bytes written to out.
    
    Throws:
    
    DataLengthException - if the output buffer is too small.
  - doFinal
```
public int doFinal(byte[] out,
                   int outOff)
            throws java.lang.IllegalStateException,
                   InvalidCipherTextException
```
    Description copied from interface: AEADCipher
    
    Finish the operation either appending or verifying the MAC at the end of the data.
    
    Specified by:
    
    doFinal in interface AEADCipher
    
    Parameters:
    
    out - space for any resulting output data.
    
    outOff - offset into out to start copying the data at.
    
    Returns:
    
    number of bytes written into out.
    
    Throws:
    
    java.lang.IllegalStateException - if the cipher is in an inappropriate state.
    
    InvalidCipherTextException - if the MAC fails to match.
  - reset
```
public void reset()
```
    Description copied from interface: AEADCipher
    
    Reset the cipher. After resetting the cipher is in the same state as it was after the last init (if there was one).
    
    Specified by:
    
    reset in interface AEADCipher
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object

Class GCMBlockCipher

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

GCMBlockCipher

GCMBlockCipher

Method Detail

newInstance

newInstance

getUnderlyingCipher

getAlgorithmName

init

getMac

getOutputSize

getUpdateOutputSize

processAADByte

processAADBytes

processByte

processBytes

doFinal

reset

toString