SHOW Signed

net.rim.device.api.crypto
Class CBCDecryptorEngine

java.lang.Object
  |
  +--net.rim.device.api.crypto.CBCDecryptorEngine

All Implemented Interfaces:

BlockDecryptorEngine

public final class CBCDecryptorEngine

extends Object

implements BlockDecryptorEngine

Provides the functionality of using CBC or Cipher Block Chaining mode for decryption. CBC mode is defined in FIPS 81.

CBC Mode is defined where the encryption of each block depends on the encryption of the previous block. Note also that with CBC mode an Initialization Vector (IV) is required. If one is not supplied a random IV is generated.

For a code sample using the CBC decryptor engine, click here.

Category:

Signed: This element is only accessible by signed clients. If you intend to use this element, please contact RIM to establish the necessary agreements that will allow you to have your COD files signed. Signing is only required for use on the device, development under the JDE can occur without signing the CODs.

Since:

JDE 3.6.0

See Also:

CBCEncryptorEngine

Constructor Summary

CBCDecryptorEngine(BlockDecryptorEngine engine, InitializationVector iv) Creates a CBC decryptor engine given an algorithm engine and an initialization vector.

Method Summary

	void	decrypt(byte[] ciphertext, int ciphertextOffset, byte[] plaintext, int plaintextOffset) Decodes a block of the given ciphertext into a block of plaintext.
	String	getAlgorithm() Returns the name of the encryption algorithm used, ie BlockDecryptorEngine.getAlgorithm() + "/CBC".
	int	getBlockLength() Returns the block length of the block cipher in bytes.
	InitializationVector	getIV() Returns the initialization vector associated with this decryptor engine.
	void	setIV(InitializationVector iv) Sets the initialization vector associated with this decryptor engine.

Methods inherited from class java.lang.Object

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

Constructor Detail

CBCDecryptorEngine

public CBCDecryptorEngine(BlockDecryptorEngine engine,
                          InitializationVector iv)

Creates a CBC decryptor engine given an algorithm engine and an initialization vector.

Parameters:

engine - The algorithm engine used for decryption.

iv - An initialization vector used for seeding the engine.

Since:

JDE 3.6.0

Category:

Signed: This element is only accessible by signed clients. If you intend to use this element, please contact RIM to establish the necessary agreements that will allow you to have your COD files signed. Signing is only required for use on the device, development under the JDE can occur without signing the CODs.

Method Detail

getAlgorithm

public String getAlgorithm()

Returns the name of the encryption algorithm used, ie BlockDecryptorEngine.getAlgorithm() + "/CBC".

Specified by:

getAlgorithm in interface BlockDecryptorEngine

Returns:

A string that represents the name of the algorithm used.

Since:

JDE 3.6.0

Category:

Signed: This element is only accessible by signed clients. If you intend to use this element, please contact RIM to establish the necessary agreements that will allow you to have your COD files signed. Signing is only required for use on the device, development under the JDE can occur without signing the CODs.

getBlockLength

public int getBlockLength()

Description copied from interface: BlockDecryptorEngine

Returns the block length of the block cipher in bytes.

Specified by:

getBlockLength in interface BlockDecryptorEngine

Since:

JDE 3.6.0

Category:

Signed: This element is only accessible by signed clients. If you intend to use this element, please contact RIM to establish the necessary agreements that will allow you to have your COD files signed. Signing is only required for use on the device, development under the JDE can occur without signing the CODs.

setIV

public void setIV(InitializationVector iv)

Sets the initialization vector associated with this decryptor engine.

Parameters:

iv - An initialization vector used for seeding the engine.

Since:

JDE 4.0.0

See Also:

getIV()

Category:

Signed: This element is only accessible by signed clients. If you intend to use this element, please contact RIM to establish the necessary agreements that will allow you to have your COD files signed. Signing is only required for use on the device, development under the JDE can occur without signing the CODs.

getIV

public InitializationVector getIV()

Returns the initialization vector associated with this decryptor engine.

Returns:

The initialization vector.

Since:

JDE 3.6.0

See Also:

setIV(net.rim.device.api.crypto.InitializationVector)

Category:

Signed: This element is only accessible by signed clients. If you intend to use this element, please contact RIM to establish the necessary agreements that will allow you to have your COD files signed. Signing is only required for use on the device, development under the JDE can occur without signing the CODs.

decrypt

public void decrypt(byte[] ciphertext,
                    int ciphertextOffset,
                    byte[] plaintext,
                    int plaintextOffset)
             throws CryptoTokenException

Description copied from interface: BlockDecryptorEngine

Decodes a block of the given ciphertext into a block of plaintext.

Specified by:

decrypt in interface BlockDecryptorEngine

Since:

JDE 4.0.0

Category:

Signed: This element is only accessible by signed clients. If you intend to use this element, please contact RIM to establish the necessary agreements that will allow you to have your COD files signed. Signing is only required for use on the device, development under the JDE can occur without signing the CODs.