crypto
Class CipherEngine

java.lang.Object
  crypto.CipherEngine

public class CipherEngine
extends java.lang.Object

Common ciphering engine (for the whole application) providing: - Asymmetric ciphering: used for signing/verification and encryption/decryption of secret key used in symmetric ciphering. - Symmetric ciphering: used for encryption/decryption of PDUs and secret chat text messages.

Field Summary

private static java.lang.String	defaultPrivateKeyDirectory Subdirectory of the user.home where private key is stored
private static java.lang.String	myCipherAlgorithm The default cipher algorithm for data (PDUs and secret chat messages)
private static int	myCipherKeySize The default key size for cipher algorithm
private static SymmetricCipher	myPduCipher Symmetric cipher used to encrypt data (PDUs and secret chat messages)
private static java.lang.String	myPrivateKeyPath Full path of the directory holding our private key
private static AsymmetricCipher	privateCipher Asymmetric cipher used to encrypt secret keys

Constructor Summary

CipherEngine()

Method Summary

static SymmetricCipher	deserializeEncryptedSecretKey(java.lang.String encryptedSecret) Reconstructs secret key from Base64 respresentation of encrypted (using our public key) serialized secret key and verifies signature of the remote peer.
static boolean	generateNewSecret(java.lang.String algorithm, int keySize, boolean verbose) Generates new symmetric secret key.
static SymmetricCipher	getCipher() Returns local symmetric ciphering engine
static java.lang.String	getNamedPublicKey() Returns serialized named public key encoded as Base64 string.
static java.lang.String	getPrivateKeyDirectory() Returns path to the directory holding our private key
static java.lang.String	getSignedPublicKey() Returns serialized signed public key (used for encryption of datagrams) as Base64 string.
static java.security.SignedObject	getSignedSecretKey() Returns secret key signed with our private key
static void	initialize() Loads authorized public keys and initializes asymmetric and symmetric ciphering engines, where: - Asymmetric ciphering is used for verification and encryption/decryption of secret key used in symmetric ciphering
static void	reloadAuthorizedPublicKeys() Reloads only authorized public keys

Methods inherited from class java.lang.Object

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

Field Detail

privateCipher

private static AsymmetricCipher privateCipher

Asymmetric cipher used to encrypt secret keys

myCipherAlgorithm

private static final java.lang.String myCipherAlgorithm

The default cipher algorithm for data (PDUs and secret chat messages)

See Also:

Constant Field Values

myCipherKeySize

private static final int myCipherKeySize

The default key size for cipher algorithm

See Also:

Constant Field Values

defaultPrivateKeyDirectory

private static final java.lang.String defaultPrivateKeyDirectory

Subdirectory of the user.home where private key is stored

See Also:

Constant Field Values

myPrivateKeyPath

private static java.lang.String myPrivateKeyPath

Full path of the directory holding our private key

myPduCipher

private static SymmetricCipher myPduCipher

Symmetric cipher used to encrypt data (PDUs and secret chat messages)

Constructor Detail

CipherEngine

public CipherEngine()

Method Detail

getPrivateKeyDirectory

public static java.lang.String getPrivateKeyDirectory()

Returns path to the directory holding our private key

getSignedPublicKey

public static java.lang.String getSignedPublicKey()

Returns serialized signed public key (used for encryption of datagrams) as Base64 string.

getNamedPublicKey

public static java.lang.String getNamedPublicKey()

Returns serialized named public key encoded as Base64 string.

getCipher

public static SymmetricCipher getCipher()

Returns local symmetric ciphering engine

getSignedSecretKey

public static java.security.SignedObject getSignedSecretKey()

Returns secret key signed with our private key

deserializeEncryptedSecretKey

public static SymmetricCipher deserializeEncryptedSecretKey(java.lang.String encryptedSecret)

Reconstructs secret key from Base64 respresentation of encrypted (using our public key) serialized secret key and verifies signature of the remote peer.

initialize

public static void initialize()

Loads authorized public keys and initializes asymmetric and symmetric ciphering engines, where: - Asymmetric ciphering is used for verification and encryption/decryption of secret key used in symmetric ciphering. - Symmetric ciphering is used for encryption/decryption of PDUs and secret chat text messages. Initialization is non-blocking and performed in separate worker thread.

reloadAuthorizedPublicKeys

public static void reloadAuthorizedPublicKeys()

Reloads only authorized public keys

generateNewSecret

public static boolean generateNewSecret(java.lang.String algorithm,
                                        int keySize,
                                        boolean verbose)

Generates new symmetric secret key.

Returns:

true if generated cipher may be used (i.e. false in case of error)