de.unikassel.android.sdcframework.util.facade
Class Encryption

java.lang.Object
  de.unikassel.android.sdcframework.util.facade.Encryption

public final class Encryption
extends Object

Utility class for encryption and checksums.

Field Summary

static String	PRIVATE_KEY_FILE private key file name
static String	PUBLIC_KEY_FILE public key file name
private static String	RSA_ALGORITHM The RSA algorithm description
private static String	RSA_ENCRYPTION The RSA transformation description for encryption
private static int	RSA_KEY_LENGTH The RSA key length

Constructor Summary

Encryption()

Method Summary

static KeyPair	createRSAKeyPair() Method to create an RSA key pair of RSA_KEY_LENGTH bit length and save the key bytes to files.
static boolean	decryptRSA(PrivateKey key, File srcFile, File destFile) Method for RSA file decryption
static boolean	encryptRSA(PublicKey key, File srcFile, File destFile) Method for RSA file encryption
static String	md5(String text) Method to create an MD5 hash for a given string
static PrivateKey	readPrivateKeyFromFile(File file) Method to read a private key from file
static PublicKey	readPublicKeyFromFile(File file) Method to read a public key from file
static PublicKey	readPublicKeyFromStream(InputStream is) Method to read a public key from an input stream
private static byte[]	readRSAKeyFromFile(File file) Method to store a public or a private RSA key bytes
static byte[]	readRSAKeyFromStream(InputStream is) Method to store a public or a private RSA key bytes
static void	saveRSAKeyToFile(String file, byte[] bytes) Method to store a public or a private RSA key bytes

Methods inherited from class java.lang.Object

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

Field Detail

PRIVATE_KEY_FILE

public static final String PRIVATE_KEY_FILE

private key file name

See Also:

Constant Field Values

PUBLIC_KEY_FILE

public static final String PUBLIC_KEY_FILE

public key file name

See Also:

Constant Field Values

RSA_KEY_LENGTH

private static final int RSA_KEY_LENGTH

The RSA key length

See Also:

Constant Field Values

RSA_ALGORITHM

private static final String RSA_ALGORITHM

The RSA algorithm description

See Also:

Constant Field Values

RSA_ENCRYPTION

private static final String RSA_ENCRYPTION

The RSA transformation description for encryption

See Also:

Constant Field Values

Constructor Detail

Encryption

public Encryption()

Method Detail

md5

public static final String md5(String text)

Method to create an MD5 hash for a given string

Parameters:

text - the string to create MD5 hash for

Returns:

the MD5 hash for the text

encryptRSA

public static final boolean encryptRSA(PublicKey key,
                                       File srcFile,
                                       File destFile)

Method for RSA file encryption

Parameters:

key - the public key to use for encryption

srcFile - the source file to encrypt

destFile - the file to store encrypted data in

Returns:

true if successful, false otherwise

decryptRSA

public static final boolean decryptRSA(PrivateKey key,
                                       File srcFile,
                                       File destFile)

Method for RSA file decryption

Parameters:

key - the private key to use for decryption

srcFile - the source file to decrypt

destFile - the file to store decrypted data in

Returns:

true if successful, false otherwise

createRSAKeyPair

public static final KeyPair createRSAKeyPair()

Method to create an RSA key pair of RSA_KEY_LENGTH bit length and save the key bytes to files.

Returns:

the genrated key pair

saveRSAKeyToFile

public static final void saveRSAKeyToFile(String file,
                                          byte[] bytes)
                                   throws IOException

Method to store a public or a private RSA key bytes

Parameters:

file - the file to save the key into

bytes - the key bytes

Throws:

IOException

readPublicKeyFromFile

public static final PublicKey readPublicKeyFromFile(File file)

Method to read a public key from file

Parameters:

file - the file to read the public key from

Returns:

the public key

readPublicKeyFromStream

public static final PublicKey readPublicKeyFromStream(InputStream is)

Method to read a public key from an input stream

Parameters:

is - the input stream to read from

Returns:

the public key

readPrivateKeyFromFile

public static final PrivateKey readPrivateKeyFromFile(File file)

Method to read a private key from file

Parameters:

file - the file to read the private key from

Returns:

the private key

readRSAKeyFromFile

private static final byte[] readRSAKeyFromFile(File file)
                                        throws IOException

Method to store a public or a private RSA key bytes

Parameters:

file - the file to read the public key from

Returns:

the key bytes

Throws:

IOException

readRSAKeyFromStream

public static final byte[] readRSAKeyFromStream(InputStream is)
                                         throws IOException

Method to store a public or a private RSA key bytes

Parameters:

is - the input stream to read the public key from

Returns:

the key bytes

Throws:

IOException