Package org.bouncycastle.crypto

## Interface BlockCipher

- All Known Implementing Classes:
    `AESEngine`, `AESFastEngine`, `AESLightEngine`, `ARIAEngine`, `BlowfishEngine`, `CamelliaEngine`, `CamelliaLightEngine`, `CAST5Engine`, `CAST6Engine`, `CBCBlockCipher`, `CFBBlockCipher`, `DESedeEngine`, `DESEngine`, `DSTU7624Engine`, `G3413CBCBlockCipher`, `G3413CFBBlockCipher`, `G3413CTRBlockCipher`, `G3413OFBBlockCipher`, `GCFBBlockCipher`, `GOFBBlockCipher`, `GOST28147Engine`, `GOST3412_2015Engine`, `IDEAEngine`, `KCTRBlockCipher`, `NoekeonEngine`, `NullEngine`, `OFBBlockCipher`, `OpenPGPCFBBlockCipher`, `PGPCFBBlockCipher`, `RC2Engine`, `RC532Engine`, `RC564Engine`, `RC6Engine`, `RijndaelEngine`, `SEEDEngine`, `SerpentEngine`, `SerpentEngineBase`, `Shacal2Engine`, `SICBlockCipher`, `SkipjackEngine`, `SM4Engine`, `StreamBlockCipher`, `TEAEngine`, `ThreefishEngine`, `TnepresEngine`, `TwofishEngine`, `XTEAEngine`

      public interface BlockCipher

  Block cipher engines are expected to conform to this interface.

- - ### Method Summary

    All Methods Instance Methods Abstract Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `java.lang.String` | `getAlgorithmName()` | Return the name of the algorithm the cipher implements.
    `int` | `getBlockSize()` | Return the block size for this cipher (in bytes).
    `void` | `init​(boolean forEncryption, CipherParameters params)` | Initialise the cipher.
    `int` | `processBlock​(byte[] in, int inOff, byte[] out, int outOff)` | Process one block of input from the array in and write it to the out array.
    `void` | `reset()` | Reset the cipher.

- - ### Method Detail

    - #### init

          void init​(boolean forEncryption,
                    CipherParameters params)
             throws java.lang.IllegalArgumentException

      Initialise the cipher.
      Parameters:
        `forEncryption` - if true the cipher is initialised for encryption, if false for decryption.
        `params` - the key and other data required by the cipher.
      Throws:
        `java.lang.IllegalArgumentException` - if the params argument is inappropriate.

    - #### getAlgorithmName

          java.lang.String getAlgorithmName()

      Return the name of the algorithm the cipher implements.
      Returns:
        the name of the algorithm the cipher implements.

    - #### getBlockSize

          int getBlockSize()

      Return the block size for this cipher (in bytes).
      Returns:
        the block size for this cipher in bytes.

    - #### processBlock

          int processBlock​(byte[] in,
                           int inOff,
                           byte[] out,
                           int outOff)
                    throws DataLengthException,
                           java.lang.IllegalStateException

      Process one block of input from the array in and write it to the out array.
      Parameters:
        `in` - the array containing the input data.
        `inOff` - offset into the in array the data starts at.
        `out` - the array the output data will be copied into.
        `outOff` - the offset into the out array the output will start at.
      Returns:
        the number of bytes processed and produced.
      Throws:
        `DataLengthException` - if there isn't enough data in in, or space in out.
        `java.lang.IllegalStateException` - if the cipher isn't initialised.

    - #### reset

          void reset()

      Reset the cipher. After resetting the cipher is in the same state as it was after the last init (if there was one).