de.flexiprovider.core.pbe
Class PBEWithSHA1AndDES_CBC

java.lang.Object
  |
  +--javax.crypto.CipherSpi
        |
        +--de.flexiprovider.api.Cipher
              |
              +--de.flexiprovider.core.pbe.interfaces.PBES1
                    |
                    +--de.flexiprovider.core.pbe.PBES1
                          |
                          +--de.flexiprovider.core.pbe.PBEWithSHA1AndDES_CBC

public class PBEWithSHA1AndDES_CBC

extends PBES1

This class implements passphrase based encryption (PBE) as defined in PKCS#5 version 2.0. The key for the cipher (here DES) is derived from the passphrase by applying a hashfunction (here SHA-1) several times on it. Because we don't provide single DES, DESede with the same key for encryption, decryption, encryption is used instead.

Author:

Thomas Wahrenbruch

Field Summary

static java.lang.String

OID The OID of PBEWithSHA1AndDES_CBC.

Fields inherited from class de.flexiprovider.core.pbe.PBES1

cipher, kdf

Fields inherited from class de.flexiprovider.api.Cipher

DECRYPT_MODE, ENCRYPT_MODE, opMode

Constructor Summary

PBEWithSHA1AndDES_CBC()
The default constructor tries to initialize the message digest, the secret key factory and the cipher.

Method Summary

int	getKeySize(Key key) Returns the key size of the given key object.
java.lang.String	getName()
void	initDecrypt(Key key, AlgorithmParameterSpec params) Initializes this cipher with a key, a set of algorithm parameters, and a source of randomness.
void	initEncrypt(Key key, AlgorithmParameterSpec params, SecureRandom random) Initializes this cipher with a key, a set of algorithm parameters, and a source of randomness.

Methods inherited from class de.flexiprovider.core.pbe.PBES1

doFinal, doFinal, getBlockSize, getIV, getOutputSize, getParameters, setMode, setPadding, update, update

Methods inherited from class de.flexiprovider.core.pbe.interfaces.PBES1

engineInit

Methods inherited from class de.flexiprovider.api.Cipher

doFinal, doFinal, engineDoFinal, engineDoFinal, engineGetBlockSize, engineGetIV, engineGetKeySize, engineGetOutputSize, engineGetParameters, engineInit, engineInit, engineSetMode, engineSetPadding, engineUpdate, engineUpdate, update

Methods inherited from class java.lang.Object

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

Field Detail

OID

public static final java.lang.String OID

The OID of PBEWithSHA1AndDES_CBC.

Constructor Detail

PBEWithSHA1AndDES_CBC

public PBEWithSHA1AndDES_CBC()

The default constructor tries to initialize the message digest, the secret key factory and the cipher.

Method Detail

getName

public java.lang.String getName()

Overrides:

getName in class Cipher

Returns:

the name of this cipher

getKeySize

public int getKeySize(Key key)
               throws InvalidKeyException

Returns the key size of the given key object. Since the cipher underlying this PBE scheme is DES, we always return 56 as the effective key size if the key is valid.

Overrides:

getKeySize in class Cipher

Parameters:

key - the key object

Returns:

the key size of the given key object.

Throws:

InvalidKeyException - if key is not an instance of PBEKey

initEncrypt

public void initEncrypt(Key key,
                        AlgorithmParameterSpec params,
                        SecureRandom random)
                 throws InvalidKeyException,
                        InvalidAlgorithmParameterException

Initializes this cipher with a key, a set of algorithm parameters, and a source of randomness.

The cipher is initialized for encryption.

If this cipher requires any algorithm parameters and params is null, the underlying cipher implementation is supposed to generate the required parameters itself (using provider-specific default or random values) if it is being initialized for encryption, and raise an InvalidAlgorithmParameterException if it is being initialized for decryption. The generated parameters can be retrieved using engineGetParameters or engineGetIV (if the parameter is an IV).

If this cipher (including its underlying feedback or padding scheme) requires any random bytes (e.g., for parameter generation), it will get them from random.

Note that when a Cipher object is initialized, it loses all previously-acquired state. In other words, initializing a Cipher is equivalent to creating a new instance of that Cipher and initializing it.

Overrides:

initEncrypt in class Cipher

Parameters:

key - the encryption key

params - the algorithm parameters

random - the source of randomness

Throws:

InvalidKeyException - if the given key is inappropriate for initializing this cipher

InvalidAlgorithmParameterException - if the given algorithm parameters are inappropriate for this cipher, or if this cipher is being initialized fro decryption and requires algorithm parameters and params is null

initDecrypt

public void initDecrypt(Key key,
                        AlgorithmParameterSpec params)
                 throws InvalidKeyException,
                        InvalidAlgorithmParameterException

Initializes this cipher with a key, a set of algorithm parameters, and a source of randomness.

The cipher is initialized for decryption.

If this cipher requires any algorithm parameters and params is null, the underlying cipher implementation is supposed to generate the required parameters itself (using provider-specific default or random values) if it is being initialized for encryption, and raise an InvalidAlgorithmParameterException if it is being initialized for decryption. The generated parameters can be retrieved using engineGetParameters or engineGetIV (if the parameter is an IV).

If this cipher (including its underlying feedback or padding scheme) requires any random bytes (e.g., for parameter generation), it will get them from random.

Note that when a Cipher object is initialized, it loses all previously-acquired state. In other words, initializing a Cipher is equivalent to creating a new instance of that Cipher and initializing it.

Overrides:

initDecrypt in class Cipher

Parameters:

key - the encryption key

params - the algorithm parameters

Throws:

InvalidKeyException - if the given key is inappropriate for initializing this cipher

InvalidAlgorithmParameterException - if the given algorithm parameters are inappropriate for this cipher, or if this cipher is being initialized fro decryption and requires algorithm parameters and params is null