org.ifeth.sehr.core.lib

Class DeEncrypter

java.lang.Object

org.ifeth.sehr.core.lib.DeEncrypter

public class DeEncrypter
extends java.lang.Object

Encrypt and decrypt strings and file streams.

Some terminology:

• Encrypt: Scrambling data to make it unrecognizable
• Decrypt: Unscrambling data to its original format
• Cipher: Another word for algorithm
• Encrypt: Scrambling data to make it unrecognizable
• Key: A complex sequence of alpha-numeric characters, produced by the algorithm, that allows you to scramble and unscramble data
• Plaintext: Decrypted or unencrypted data (it doesn’t have to be text only)
• Ciphertext: Data that has been encrypted

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	PBEAlgorhythm

Constructor Summary

Constructors

Constructor and Description
DeEncrypter() Parameterless Constructor.

Method Summary

Modifier and Type	Method and Description
boolean	configureAES(java.lang.String pass)
boolean	configurePBE(java.lang.String pass) Configure a password (or PIN) based en/decryption.
java.lang.String	decrypt(java.lang.String ciphertext) Decrypt a given string (DE: Entschluesselt eine Zeichenkette, welche mit der Methode encrypt verschluesselt wurde).
void	decryptFile(java.lang.String encryptedSrcFile, java.lang.String decryptedDstFile) Symetric decryption of given encrypted file.
void	decryptInputStream(java.io.InputStream encryptedInpStream, java.io.OutputStream decryptedOutStream) Symetric decryption of given encrypted input stream.
java.lang.String	encrypt(java.lang.String str) Encrypt a string (DE: Verschluesselt Zeichenkette).
void	encryptFile(java.lang.String srcFile, java.lang.String encryptedDstFile) Encrypt given file (by path) using the symetric encryption.
void	encryptInputStream(java.io.InputStream inStream, java.io.OutputStream encryptedOutStream) Encrypt given input stream using the symetric encryption.
java.lang.String	getCharset()
javax.crypto.CipherInputStream	getCipherInputStream(java.io.FileInputStream fis) Input stream with cipher.
javax.crypto.CipherOutputStream	getCipherOutputStream(java.io.FileOutputStream fos) Output stream with cipher.
javax.crypto.Cipher	getDecryptionCipher() Get cipher for decryption.
javax.crypto.Cipher	getEncryptionCipher() Get cipher instance for encryption based on configuration.
java.lang.String	getErrorMessage() Returns the last errorMessage.
static java.lang.String	getMD5Password(java.lang.String plainText) Encrypts a given string into a MD5 hash.
javax.crypto.Cipher	initDecryptionCipher(java.lang.String password, java.lang.String type) Initialize DeEncrypter by password (or phrase) and type.
javax.crypto.Cipher	initEncryptionCipher(java.lang.String password, java.lang.String type)
boolean	isAESCipher() If 'true' the PBE key is usable.
boolean	isPBECipher() If 'true' the PBE key is usable.
void	loadKey(java.io.File inAESKeyFile, java.security.PrivateKey pk) Load the AESKey to decrypt files.
void	saveKey(java.io.File outAESKeyFile, java.security.PublicKey pk)
void	setCharset(java.lang.String charset)

Methods inherited from class java.lang.Object

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

Field Detail

PBEAlgorhythm

public static final java.lang.String PBEAlgorhythm

See Also:

Constant Field Values

Constructor Detail

DeEncrypter

public DeEncrypter()

Parameterless Constructor.

Method Detail

configurePBE

public boolean configurePBE(java.lang.String pass)

Configure a password (or PIN) based en/decryption.

Parameters:

pass -

Returns:

configureAES

public boolean configureAES(java.lang.String pass)

getCharset

public java.lang.String getCharset()

Returns:

the charset

setCharset

public void setCharset(java.lang.String charset)

Parameters:

charset - the charset to set

isPBECipher

public boolean isPBECipher()

If 'true' the PBE key is usable.

Returns:

true if process has been successful

isAESCipher

public boolean isAESCipher()

If 'true' the PBE key is usable.

Returns:

true if process has been successful

getEncryptionCipher

public javax.crypto.Cipher getEncryptionCipher()

Get cipher instance for encryption based on configuration.

Returns:

Cipher - 'null' if not successful, details stored in 'errorMessage'

getDecryptionCipher

public javax.crypto.Cipher getDecryptionCipher()

Get cipher for decryption.

Returns:

cipher for decryption or null

initDecryptionCipher

public javax.crypto.Cipher initDecryptionCipher(java.lang.String password,
                                                java.lang.String type)

Initialize DeEncrypter by password (or phrase) and type.

On AES the password can be blank and will be created then by the system.
N.B.On system algorithms you have no password. You must use the generated cipher also for decrypting.

Parameters:

password -

type - "AES" (password or generated) or "PBE" (password based encryption)

Returns:

initEncryptionCipher

public javax.crypto.Cipher initEncryptionCipher(java.lang.String password,
                                                java.lang.String type)

Parameters:

password -

type - "AES" (password or generated) or "PBE" (password based encryption)

Returns:

getCipherInputStream

public javax.crypto.CipherInputStream getCipherInputStream(java.io.FileInputStream fis)

Input stream with cipher.

Parameters:

fis - - FileInputStream

Returns:

CipherInputStream_Object - CipherInputStream (decrypted) oder null

getCipherOutputStream

public javax.crypto.CipherOutputStream getCipherOutputStream(java.io.FileOutputStream fos)

Output stream with cipher.

Parameters:

fos - - FileOutputStream

Returns:

CipherOutputStream_Object - CipherOutputStream (encrypted) oder null

encrypt

public java.lang.String encrypt(java.lang.String str)
                         throws java.lang.SecurityException

Encrypt a string (DE: Verschluesselt Zeichenkette).

Parameters:

str - Plain text to cipher (crypt)

Returns:

The encrypted string.

Throws:

java.lang.SecurityException - Description of the Exception

decrypt

public java.lang.String decrypt(java.lang.String ciphertext)
                         throws java.lang.SecurityException

Decrypt a given string (DE: Entschluesselt eine Zeichenkette, welche mit der Methode encrypt verschluesselt wurde).

Parameters:

ciphertext - The encrypted string.

Returns:

The plaintext of the encrypted string.

Throws:

java.lang.SecurityException - Description of the Exception.

encryptFile

public void encryptFile(java.lang.String srcFile,
                        java.lang.String encryptedDstFile)
                 throws java.security.GeneralSecurityException,
                        java.io.IOException

Encrypt given file (by path) using the symetric encryption.

Symmetric-key encryptionmeans the same key is used to both encrypt and decrypt. It sometimes called secret-key encryption, single-key encryption or simply symmetric encryption.

Parameters:

srcFile - source file to encrypt

encryptedDstFile - the encrypted file

Throws:

java.security.GeneralSecurityException

java.io.IOException

encryptInputStream

public void encryptInputStream(java.io.InputStream inStream,
                               java.io.OutputStream encryptedOutStream)
                        throws java.security.GeneralSecurityException,
                               java.io.IOException

Encrypt given input stream using the symetric encryption.

Streams werden mit close() geschlossen.

Parameters:

inStream -

encryptedOutStream -

Throws:

java.security.GeneralSecurityException

java.io.IOException

decryptFile

public void decryptFile(java.lang.String encryptedSrcFile,
                        java.lang.String decryptedDstFile)
                 throws java.security.GeneralSecurityException,
                        java.io.IOException

Symetric decryption of given encrypted file.

Use configureAES(java.lang.String) to configure the processor.

Parameters:

encryptedSrcFile -

decryptedDstFile -

Throws:

java.security.GeneralSecurityException

java.io.IOException

decryptInputStream

public void decryptInputStream(java.io.InputStream encryptedInpStream,
                               java.io.OutputStream decryptedOutStream)
                        throws java.security.GeneralSecurityException,
                               java.io.IOException

Symetric decryption of given encrypted input stream.

Use configureAES(java.lang.String) to configure the processor.

Streams werden mit close() geschlossen.

Throws:

java.security.GeneralSecurityException

java.io.IOException

getMD5Password

public static java.lang.String getMD5Password(java.lang.String plainText)
                                       throws java.security.NoSuchAlgorithmException

Encrypts a given string into a MD5 hash. This is a one way encryption.

Parameters:

plainText - string to encrypt

Returns:

md5 hash

Throws:

java.security.NoSuchAlgorithmException - possible exception

saveKey

public void saveKey(java.io.File outAESKeyFile,
                    java.security.PublicKey pk)
             throws java.io.IOException,
                    java.security.GeneralSecurityException

Throws:

java.io.IOException

java.security.GeneralSecurityException

loadKey

public void loadKey(java.io.File inAESKeyFile,
                    java.security.PrivateKey pk)
             throws java.security.GeneralSecurityException,
                    java.io.IOException

Load the AESKey to decrypt files. Before decryption can take place, the encrypted key must be prepared using the RSA private key.

Parameters:

inAESKeyFile -

pk -

Throws:

java.security.GeneralSecurityException

java.io.IOException

getErrorMessage

public java.lang.String getErrorMessage()

Returns the last errorMessage.

Returns:

string