org.bouncycastle.crypto.engines

## Class IDEAEngine

- java.lang.Object
- - org.bouncycastle.crypto.engines.IDEAEngine

All Implemented Interfaces:
  BlockCipher

    public class IDEAEngine
    extends java.lang.Object
    implements BlockCipher

A class that provides a basic International Data Encryption Algorithm (IDEA) engine.

This implementation is based on the "HOWTO: INTERNATIONAL DATA ENCRYPTION ALGORITHM" implementation summary by Fauzan Mirza (F.U.Mirza@sheffield.ac.uk). (baring 1 typo at the end of the mulinv function!).

It can be found at ftp://ftp.funet.fi/pub/crypt/cryptography/symmetric/idea/

Note 1: This algorithm is patented in the USA, Japan, and Europe including at least Austria, France, Germany, Italy, Netherlands, Spain, Sweden, Switzerland and the United Kingdom. Non-commercial use is free, however any commercial products are liable for royalties. Please see www.mediacrypt.com for further details. This announcement has been included at the request of the patent holders.

Note 2: Due to the requests concerning the above, this algorithm is now only included in the extended Bouncy Castle provider and JCE signed jars. It is not included in the default distributions.

### Field Summary

Fields
`protected static int` `BLOCK_SIZE`

### Constructor Summary

Constructors
Constructor and Description
`IDEAEngine()` standard constructor.

### Method Summary

Methods
`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 an IDEA 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.

### Methods inherited from class java.lang.Object

`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

### Field Detail

#### BLOCK_SIZE

    protected static final int BLOCK_SIZE

See Also:
  Constant Field Values

### Constructor Detail

#### IDEAEngine

    public IDEAEngine()

standard constructor.

### Method Detail

#### init

    public void init(boolean forEncryption,
            CipherParameters params)

initialise an IDEA cipher.

Specified by:
  `init` in interface `BlockCipher`
Parameters:
  `forEncryption` - whether or not we are for encryption.
  `params` - the parameters required to set up the cipher.
Throws:
  `java.lang.IllegalArgumentException` - if the params argument is inappropriate.

#### getAlgorithmName

    public java.lang.String getAlgorithmName()

Description copied from interface: `BlockCipher`
Return the name of the algorithm the cipher implements.

Specified by:
  `getAlgorithmName` in interface `BlockCipher`
Returns:
  the name of the algorithm the cipher implements.

#### getBlockSize

    public int getBlockSize()

Description copied from interface: `BlockCipher`
Return the block size for this cipher (in bytes).

Specified by:
  `getBlockSize` in interface `BlockCipher`
Returns:
  the block size for this cipher in bytes.

#### processBlock

    public int processBlock(byte[] in,
                   int inOff,
                   byte[] out,
                   int outOff)

Description copied from interface: `BlockCipher`
Process one block of input from the array in and write it to the out array.

Specified by:
  `processBlock` in interface `BlockCipher`
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.

#### reset

    public void reset()

Description copied from interface: `BlockCipher`
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 `BlockCipher`