com.arsdigita.kernel.security
Class Crypto

java.lang.Object
  com.arsdigita.kernel.security.Crypto

public class Crypto

extends Object

Provides cryptographic functions and stores the server's secret key.

Since:

ACS 4.5

Author:

Sameer Ajmani

Field Summary

static String	CHARACTER_ENCODING
static String	versionId

Constructor Summary

Crypto()

Method Summary

static String	decrypt(String encrypted, char[] password) Decrypts a string with a key derived from a password.
static String	encrypt(String decrypted, char[] password) Encrypts a string with a key derived from a password.
static SecureRandom	getRandom() Returns a secure random number generator.
static void	main(String[] args) Benchmarks password-based encryption and decryption.
static MessageDigest	newDigester() Creates a new message digest (hash) calculator.
static javax.crypto.Mac	newMac() Creates a new Message Authentication Code (MAC) calculator that uses the server's secret key.

Methods inherited from class java.lang.Object

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

Field Detail

versionId

public static final String versionId

See Also:

Constant Field Values

CHARACTER_ENCODING

public static final String CHARACTER_ENCODING

See Also:

Constant Field Values

Constructor Detail

Crypto

public Crypto()

Method Detail

newMac

public static javax.crypto.Mac newMac()
                               throws GeneralSecurityException

Creates a new Message Authentication Code (MAC) calculator that uses the server's secret key.

Returns:

a new Mac object.

Throws:

GeneralSecurityException - if an error occurs.

newDigester

public static MessageDigest newDigester()
                                 throws GeneralSecurityException

Creates a new message digest (hash) calculator.

Returns:

a new MessageDigest object.

Throws:

GeneralSecurityException - if an error occurs.

getRandom

public static SecureRandom getRandom()
                              throws GeneralSecurityException

Returns a secure random number generator.

Returns:

a SecureRandom number generator.

Throws:

GeneralSecurityException - if an error occurs.

encrypt

public static String encrypt(String decrypted,
                             char[] password)
                      throws GeneralSecurityException

Encrypts a string with a key derived from a password. Output is BASE64Encode(salt) + ":" + BASE64Encode(encrypt(UTF8Encode(cleartext.length() + ":" + cleartext))).

Parameters:

decrypted - the string to encrypt

password - the password from which to create an encryption key

Returns:

the encrypted string.

Throws:

GeneralSecurityException - if encryption fails.

decrypt

public static String decrypt(String encrypted,
                             char[] password)
                      throws GeneralSecurityException

Decrypts a string with a key derived from a password.

Parameters:

encrypted - the string to decrypt

password - the password from which to create an decryption key

Returns:

the decrypted string

Throws:

IllegalArgumentException - if the given string is not legal output of encrypt().

InvalidKeyException - if the decrypted text does not pass validation.

GeneralSecurityException - if decryption fails otherwise.

main

public static void main(String[] args)
                 throws GeneralSecurityException

Benchmarks password-based encryption and decryption.

Throws:

GeneralSecurityException