crypto
Class SymmetricCipher

java.lang.Object
  crypto.SymmetricCipher

public class SymmetricCipher
extends java.lang.Object

Instances of the Symmetric cipher class arew used to cipher peer-to-peer datagram packets. Cipher's secret key is exchanged using asymmetric cipher.

Author:

Mikica B Kocic

Field Summary

private javax.crypto.Cipher	cipher Instance of the cipher used to encrypt/decrypt data.
private static java.lang.String	mode Cipher-Block Chaining mode.
private static java.lang.String	padding PKCS5 padding.
private javax.crypto.SecretKey	secretKey Secret key used to encrypt/decrypt data.
private java.lang.String	verificator Contains name of the verificator (i.e the name associated with authorized public key that has verified this public key).

Constructor Summary

SymmetricCipher(javax.crypto.SecretKey secretKey, java.lang.String verificator)
Wraps existing secret key with information about verificatory (if any).

SymmetricCipher(java.lang.String algorithm, int keySize, boolean attnReport)
Generates a new secret key using specified algorithm and key size.

Method Summary

byte[]	decrypt(int randomPreambleLen, byte[] cipherText) Decrypts cipher text first then discards random preamble of the given length.
java.lang.String	decrypt(java.lang.String encodedCipherText) Decodes Base64 encoded cipher text, decrypts text message and discards random preamble.
byte[]	encrypt(int randomPreambleLen, byte[] plainText) Encrypts random preamble of the given length appended with the input plain text.
java.lang.String	encrypt(java.lang.String plainText) Encrypts text message with random preamble and returns Base64 encoded cipher text.
java.lang.String	getAlgorithmDesc() Returns description of the cipher algorithm
javax.crypto.SecretKey	getSecretKey() Returns secret key.
java.lang.String	getVerificatorName() Returns if name of the verificator from authorized keys that verified this public key
boolean	isActive() Returns if cipher is properly initialized
boolean	isVerified() Returns if public key was verified

Methods inherited from class java.lang.Object

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

Field Detail

mode

private static final java.lang.String mode

Cipher-Block Chaining mode. \see http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation

See Also:

Constant Field Values

padding

private static final java.lang.String padding

PKCS5 padding. \see http://www.ietf.org/rfc/rfc2898.txt

See Also:

Constant Field Values

cipher

private javax.crypto.Cipher cipher

Instance of the cipher used to encrypt/decrypt data.

secretKey

private javax.crypto.SecretKey secretKey

Secret key used to encrypt/decrypt data.

verificator

private java.lang.String verificator

Contains name of the verificator (i.e the name associated with authorized public key that has verified this public key). Not null indicates that the public key was successfully verified.

Constructor Detail

SymmetricCipher

public SymmetricCipher(javax.crypto.SecretKey secretKey,
                       java.lang.String verificator)

Wraps existing secret key with information about verificatory (if any).

SymmetricCipher

public SymmetricCipher(java.lang.String algorithm,
                       int keySize,
                       boolean attnReport)

Generates a new secret key using specified algorithm and key size.

Method Detail

getSecretKey

public javax.crypto.SecretKey getSecretKey()

Returns secret key.

isActive

public boolean isActive()

Returns if cipher is properly initialized

isVerified

public boolean isVerified()

Returns if public key was verified

getVerificatorName

public java.lang.String getVerificatorName()

Returns if name of the verificator from authorized keys that verified this public key

Returns:

name of the verificator; May be null indicating not verified public key

getAlgorithmDesc

public java.lang.String getAlgorithmDesc()

Returns description of the cipher algorithm

encrypt

public byte[] encrypt(int randomPreambleLen,
                      byte[] plainText)

Encrypts random preamble of the given length appended with the input plain text.

decrypt

public byte[] decrypt(int randomPreambleLen,
                      byte[] cipherText)

Decrypts cipher text first then discards random preamble of the given length.

encrypt

public java.lang.String encrypt(java.lang.String plainText)

Encrypts text message with random preamble and returns Base64 encoded cipher text.

decrypt

public java.lang.String decrypt(java.lang.String encodedCipherText)

Decodes Base64 encoded cipher text, decrypts text message and discards random preamble.