com.ibm.di.security
Class SymmetricCipherCrypto

java.lang.Object
  com.ibm.di.security.SymmetricCipherCrypto

All Implemented Interfaces:

Crypto

public class SymmetricCipherCrypto
extends Object
implements Crypto

Secret key encryption/decryption. This class can work with secret key JCE transformations like the one that javax.crypto.Cipher.getInstance accepts. It supports block ciphers (e.g. AES) in various feedback modes (ECB, CBC, CFB, ...) as well as stream ciphers (e.g. RC4). Objects of this class are thread-safe.

Since:

7.0

Constructor Summary

SymmetricCipherCrypto(String transformation, SecretKey secretKey, Provider cryptoProvider)
Initializes the object with the specified parameters.

Method Summary

byte[]	decrypt(byte[] encryptedData) Decrypt data.
byte[]	encrypt(byte[] data) Encrypt data.

Methods inherited from class java.lang.Object

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

Constructor Detail

SymmetricCipherCrypto

public SymmetricCipherCrypto(String transformation,
                             SecretKey secretKey,
                             Provider cryptoProvider)
                      throws Exception

Initializes the object with the specified parameters. Calculates the size of the initialization vector needed for the transformation. Accepts an optional Java security provider, which will be used for encryption. If the provider is set to null, the implementation will rely on the provider list configured for the JRE.

Parameters:

transformation - the name of a secret key transformation

secretKey - a secret key, suitable for the cipher of the transformation

cryptoProvider - a Java security provider

Throws:

Exception - error by the underlying JCE provider

Method Detail

encrypt

public byte[] encrypt(byte[] data)
               throws Exception

Encrypt data. If the feedback mode of the transformation requires an initialization vector (IV), a random one will be created. This makes the IV non-predictable. The encrypted data is prefixed with the IV (if required) as plaintext (the IV does not need to be kept secret).

Specified by:

encrypt in interface Crypto

Parameters:

data - plaintext

Returns:

ciphertext

Throws:

Exception - problem with encryption

decrypt

public byte[] decrypt(byte[] encryptedData)
               throws Exception

Decrypt data. If the transformation requires an initialization vector (IV), the IV used for encryption is assumed to be located in the beginning of the input buffer.

Specified by:

decrypt in interface Crypto

Parameters:

encryptedData - ciphertext

Returns:

plaintext

Throws:

Exception - problem with decryption