de.ipcon.tools

Class CryptoTools

java.lang.Object

de.ipcon.tools.CryptoTools

public class CryptoTools
extends java.lang.Object

Method Summary

Modifier and Type	Method and Description
static java.lang.String	generatePassword(int len) Generates and returns a password
static java.lang.String	generatePassword(int len, int maxSpecialChars)
static java.lang.String	generatePassword(int len, int maxSpecialChars, netrexx.lang.Rexx chars)
static java.lang.String	generatePasswordCharsAndNumbersOnly(int len) Generates and returns a password containing only of numbers and letters (excluding O, I, L, 0 and 1 which can easily be mistaken for one another).
static java.lang.String	generatePasswordCharsOnly(int len) Generates and returns a password containing only of letters (excluding O, I and L which can easily be mistaken for 0 and 1).
static java.lang.String	generatePasswordNumsOnly(int len) Generates and returns a password containing only of numbers.
static java.util.Random	getRandom() Returns a Random for generating random numbers for usage in a shared or unshared scenario.
static java.security.SecureRandom	getSharedSecureRandom() Returns a shared SecureRandom object.
static java.security.SecureRandom	getUnsharedSecureRandom() Returns an unshared SecureRandom object.
static void	setUniqueKeyModifier(int l) Sets a unique key modifier (i.e. a salt) for subsequently generating a unique key via uniqueKey()
static long	uniqueKey() A Keymaker algorithm for calculating a unique key using the previously set unique key identifier (or a default one)

Methods inherited from class java.lang.Object

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

Method Detail

setUniqueKeyModifier

public static void setUniqueKeyModifier(int l)

Sets a unique key modifier (i.e. a salt) for subsequently generating a unique key via uniqueKey()

Parameters:

l - an int to use as unique key modifier

uniqueKey

public static long uniqueKey()

A Keymaker algorithm for calculating a unique key using the previously set unique key identifier (or a default one)

Returns:

a calculated unique key

getSharedSecureRandom

public static java.security.SecureRandom getSharedSecureRandom()

Returns a shared SecureRandom object. If many threads are using a single SecureRandom, there might be contention that hurts performance. On the other hand, initializing a SecureRandom instance can be relatively slow, because SecureRandom uses an implementation of java.security.SecureRandomSpi, which will eventually be contended. So using a new SecureRandom in each thread is not a solution to lock contention problems. Anyway, SecureRandom is thread safe, so it may at least be safely shared and used concurrently, though performance might be very very bad when using e.g. lots of SSL connections which rely on SecureRandom for their crypto-handshaking magic.

getUnsharedSecureRandom

public static java.security.SecureRandom getUnsharedSecureRandom()

Returns an unshared SecureRandom object.

See Also:

getSharedSecureRandom()

getRandom

public static java.util.Random getRandom()

Returns a Random for generating random numbers for usage in a shared or unshared scenario. We are returning a ThreadLocalRandom here rather than a shared Random object, because in concurrent programs we will typically encounter much less overhead and contention when using that and there are no drawbacks because of the Random not being shared.

generatePassword

public static java.lang.String generatePassword(int len)

Generates and returns a password

Parameters:

len - the length of the desired password

maxSpecialChars - the maximum number of special characters to be contained in the generated password

chars - the selection of characters to be used for the password to be generated

Returns:

a random password

generatePassword

public static java.lang.String generatePassword(int len,
                                                int maxSpecialChars)

generatePassword

public static java.lang.String generatePassword(int len,
                                                int maxSpecialChars,
                                                netrexx.lang.Rexx chars)

generatePasswordNumsOnly

public static java.lang.String generatePasswordNumsOnly(int len)

Generates and returns a password containing only of numbers.

Parameters:

len - the length of the desired password

Returns:

a random password containing numbers only

generatePasswordCharsOnly

public static java.lang.String generatePasswordCharsOnly(int len)

Generates and returns a password containing only of letters (excluding O, I and L which can easily be mistaken for 0 and 1).

Parameters:

len - the length of the desired password

Returns:

a random password containing letters only

generatePasswordCharsAndNumbersOnly

public static java.lang.String generatePasswordCharsAndNumbersOnly(int len)

Generates and returns a password containing only of numbers and letters (excluding O, I, L, 0 and 1 which can easily be mistaken for one another).

Parameters:

len - the length of the desired password

Returns:

a random password containing letters and numbers only