Package org.forgerock.openig.util

Class Randoms

java.lang.Object

org.forgerock.openig.util.Randoms

public final class Randoms
extends Object

The Randoms utility class offers methods to generate random values.

It provides both implementation method(s) and functional interface(s) so that it's easy, in the code, to convey the meaning that random values with specific constraints are required.

In other words, a method can indicate it needs a random value to be used in a URL by having a dependency on Randoms.UrlFriendlyRandomStringGenerator. Example:

   private URI addNonceToUri(final URI original, final UrlFriendlyRandomStringGenerator generator) { ... }
 

From a usage perspective, a simple method reference can be used to provide the generator function:

 URI modified = addNonceToUri(uri, Randoms::generateSecureRandomValue)
 

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	Randoms.UrlFriendlyRandomStringGenerator	Generates a random value (cryptographically secure) that can be used in a query parameter value.

Method Summary

Modifier and Type	Method	Description
static String	generateSecureRandomBase64UrlEncoded(int byteLength)	Generates a Base64 URL encoded cryptographically secure random value for use as a query parameter value.
static String	generateSecureRandomValue()	Returns a cryptographically-secure random value (never null).
static String	generateSessionId()	Returns a cryptographically-secure random value usable as session identifier.

Methods inherited from class java.lang.Object

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

Method Details

generateSecureRandomValue

public static String generateSecureRandomValue()

Returns a cryptographically-secure random value (never null).

The generated value is URL query parameter friendly (base 36: [0-9] + [a-z]).

Returns:

a cryptographically-secure random value (never null).

generateSessionId

public static String generateSessionId()

Returns a cryptographically-secure random value usable as session identifier. (never null).

The generated value is base64 encoded.

Returns:

a cryptographically-secure random value (never null).

See Also:

• OWASP considers a 128 bit long random value as secure enough against brute force attacks

generateSecureRandomBase64UrlEncoded

public static String generateSecureRandomBase64UrlEncoded(int byteLength)

Generates a Base64 URL encoded cryptographically secure random value for use as a query parameter value. The ratio of returned length to byte length is approximately 1:1.333 so a byte length of 96 will result in a String that is 128 characters long.

Parameters:

byteLength - the length of the random bytes used to generate the Base64 URL encoded value.

Returns:

a Base64 URL encoded cryptographically secure random value.