com.bankframe.util
Class Cryptography

java.lang.Object
  com.bankframe.util.Cryptography

public class Cryptography
extends Object

This class provides a wrapper around the Java Cryptography API. This class contains methods to generate an encryption key, wrap an encryption key byte array, encrypt data and decrypt data. The user can specify the encryption algorithm and provider to use. This class requires the Java Cryptography API jars to run.

Constructor Summary

Cryptography()
Constructor

Method Summary

static byte[]	asciiArrayToByteArray(byte[] bytes) This method converts an array of ascii characters into the actual values that the ascii characters represent.
static byte[]	byteArrayToCharArray(byte[] bytes) This method converts an array of actual values into their ascii character representation.
static byte[]	decrypt(byte[] encryptedData, SecretKey masterKey, String algorithm) This method decrypts the specified data
static byte[]	decrypt(byte[] encryptedData, SecretKey masterKey, String algorithm, String provider) This method decrypts the specified data using the specified algorithm.
static byte[]	encrypt(byte[] rawData, SecretKey masterKey, String algorithm) This method encrypts the specified data
static byte[]	encrypt(byte[] rawData, SecretKey masterKey, String algorithm, String provider) This method encrypts the specified data using the specified algorithm.
static SecretKey	generateEncryptionKey(String algorithm, int keysize) This method generates a symetric encryption key using the specified algorithm.
static SecretKey	generateEncryptionKey(String algorithm, String provider, int keysize) This method generates a symetric encryption key using the specified algorithm and provider.
static SecretKey	wrapEncryptionKey(byte[] theEncryptionKey, String algorithm) This method wraps the specified symetric encryption key bytes into a SecretKey for use by the Java Cryptography API.

Methods inherited from class java.lang.Object

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

Constructor Detail

Cryptography

public Cryptography()

Constructor

Method Detail

generateEncryptionKey

public static SecretKey generateEncryptionKey(String algorithm,
                                              String provider,
                                              int keysize)
                                       throws NoSuchProviderException,
                                              NoSuchAlgorithmException

This method generates a symetric encryption key using the specified algorithm and provider. If the SunJCE provider is specified then the SunJCE security provider is added.

Parameters:

algorithm - is the name of the Encryption algorithm, e.g. DES

provider - is the name of the provider to use, e.g. SunJCE

keysize - is an algorithm-specific metric, specified in number of bits. e.g. 56 for Des encryption key

Returns:

the generated SecretKey.

Throws:

NoSuchAlgorithmException - if a particular cryptographic algorithm is requested but is not available in the environment

NoSuchProviderException - if a particular security provider is requested but is not available in the environment

generateEncryptionKey

public static SecretKey generateEncryptionKey(String algorithm,
                                              int keysize)
                                       throws NoSuchProviderException,
                                              NoSuchAlgorithmException

This method generates a symetric encryption key using the specified algorithm.

Parameters:

algorithm - is the name of the Encryption algorithm, e.g. DES

keysize - is an algorithm-specific metric, specified in number of bits. e.g. 56 for Des encryption key

Returns:

the generated SecretKey.

Throws:

NoSuchAlgorithmException - if a particular cryptographic algorithm is requested but is not available in the environment

NoSuchProviderException

wrapEncryptionKey

public static SecretKey wrapEncryptionKey(byte[] theEncryptionKey,
                                          String algorithm)
                                   throws InvalidKeyException,
                                          NoSuchAlgorithmException,
                                          InvalidKeySpecException

This method wraps the specified symetric encryption key bytes into a SecretKey for use by the Java Cryptography API.

Parameters:

theEncryptionKey - is the bytes to wrap into a Secret key

algorithm - is the algorithm to use, e.g. DES

Returns:

the wrapped SecretKey.

Throws:

NoSuchAlgorithmException - if a particular cryptographic algorithm is requested but is not available in the environment

InvalidKeyException - for invalid Keys (invalid encoding, wrong length, uninitialized, etc)

InvalidKeySpecException - for invalid key specifications

NoSuchProviderException - if a particular security provider is requested but is not available in the environment

IllegalBlockSizeException - if the length of data provided to a block cipher is incorrect, i.e., does not match the block size of the cipher

encrypt

public static byte[] encrypt(byte[] rawData,
                             SecretKey masterKey,
                             String algorithm,
                             String provider)
                      throws NoSuchPaddingException,
                             NoSuchAlgorithmException,
                             InvalidKeyException,
                             BadPaddingException,
                             NoSuchProviderException,
                             IllegalBlockSizeException

This method encrypts the specified data using the specified algorithm.

Parameters:

rawData - is the raw data to encrypt

masterKey - is the symetric encryption key to use for encryption

algorithm - is the algorithm to use, e.g. DES/ECB/NoPadding

provider - is the provider to use, e.g. SunJCE

Returns:

decrypted data

Throws:

NoSuchPaddingException - if a padding format is incorrect

NoSuchAlgorithmException - if a particular cryptographic algorithm is requested but is not available in the environment

InvalidKeyException - for invalid Keys (invalid encoding, wrong length, uninitialized, etc)

BadPaddingException - if a particular padding mechanism is expected for the input data but the data is not padded properly

NoSuchProviderException - if a particular security provider is requested but is not available in the environment

IllegalBlockSizeException - if the length of data provided to a block cipher is incorrect, i.e., does not match the block size of the cipher

encrypt

public static byte[] encrypt(byte[] rawData,
                             SecretKey masterKey,
                             String algorithm)
                      throws NoSuchPaddingException,
                             NoSuchAlgorithmException,
                             InvalidKeyException,
                             BadPaddingException,
                             NoSuchProviderException,
                             IllegalBlockSizeException

This method encrypts the specified data

Parameters:

rawData - is the raw data to encrypt

masterKey - to use for encryption

algorithm - is the algorithm to use, e.g. "DES/ECB/NoPadding"

Returns:

decrypted data

Throws:

NoSuchPaddingException - if a padding format is incorrect

NoSuchAlgorithmException - if a a particular cryptographic algorithm is requested but is not available in the environment

InvalidKeyException - for invalid Keys (invalid encoding, wrong length, uninitialized, etc)

BadPaddingException - if a particular padding mechanism is expected for the input data but the data is not padded properly

NoSuchProviderException - if a particular security provider is requested but is not available in the environment

IllegalBlockSizeException - if the length of data provided to a block cipher is incorrect, i.e., does not match the block size of the cipher

decrypt

public static byte[] decrypt(byte[] encryptedData,
                             SecretKey masterKey,
                             String algorithm,
                             String provider)
                      throws NoSuchPaddingException,
                             NoSuchAlgorithmException,
                             InvalidKeyException,
                             BadPaddingException,
                             NoSuchProviderException,
                             IllegalBlockSizeException

This method decrypts the specified data using the specified algorithm.

Parameters:

encryptedData - is the encrypted data

masterKey - to use for decryption

algorithm - is the algorithm to use, e.g. "DES/ECB/NoPadding"

provider - is the provider to use, e.g. SunJCE

Returns:

decrypted data

Throws:

NoSuchPaddingException - if a padding format is incorrect

NoSuchAlgorithmException - if a a particular cryptographic algorithm is requested but is not available in the environment

InvalidKeyException - for invalid Keys (invalid encoding, wrong length, uninitialized, etc)

BadPaddingException - if a particular padding mechanism is expected for the input data but the data is not padded properly

NoSuchProviderException - if a particular security provider is requested but is not available in the environment

IllegalBlockSizeException - if the length of data provided to a block cipher is incorrect, i.e., does not match the block size of the cipher

decrypt

public static byte[] decrypt(byte[] encryptedData,
                             SecretKey masterKey,
                             String algorithm)
                      throws NoSuchPaddingException,
                             NoSuchAlgorithmException,
                             InvalidKeyException,
                             BadPaddingException,
                             NoSuchProviderException,
                             IllegalBlockSizeException

This method decrypts the specified data

Parameters:

encryptedData - is the encrypted data

masterKey - to use for decryption

algorithm - is the algorithm to use, e.g., "DES/ECB/NoPadding"

Returns:

decrypted data

Throws:

NoSuchPaddingException - if a padding format is incorrect

NoSuchAlgorithmException - if a a particular cryptographic algorithm is requested but is not available in the environment

InvalidKeyException - for invalid Keys (invalid encoding, wrong length, uninitialized, etc)

BadPaddingException - if a particular padding mechanism is expected for the input data but the data is not padded properly

NoSuchProviderException - if a particular security provider is requested but is not available in the environment

IllegalBlockSizeException - if the length of data provided to a block cipher is incorrect, i.e., does not match the block size of the cipher

asciiArrayToByteArray

public static byte[] asciiArrayToByteArray(byte[] bytes)
                                    throws NumberFormatException

This method converts an array of ascii characters into the actual values that the ascii characters represent. This method is called on a server to convert a block of encrypted data from a client that has been transmitted in ascii text form over HTTP. The real encrypted data can then be decrypted on the server.

Parameters:

bytes - byte[] ascii characters.

Returns:

byte[] actual values.

Throws:

NumberFormatException

byteArrayToCharArray

public static byte[] byteArrayToCharArray(byte[] bytes)

This method converts an array of actual values into their ascii character representation. This method is called by a client to convert an encrypted block of data into an ascii representation. The ascii text data can then be transmitted over HTTP to the server.

Parameters:

bytes - byte[] actual values.

Returns:

byte[] ascii character representation.