[edit] Last updated: Fri, 24 Jun 2011

OAuthProvider::generateToken

(PECL OAuth >= 1.0.0)

OAuthProvider::generateToken — Generate a random token

Description

final public static string OAuthProvider::generateToken ( int $size [, bool $strong = false ] )

Generates a string of pseudo-random bytes.

Parameters

size: The desired token length, in terms of bytes.
strong: Setting to TRUE means /dev/random will be used for entropy, as otherwise the non-blocking /dev/urandom is used. This parameter is ignored on Windows.

Return Values

The generated token, as a string of bytes.

Errors/Exceptions

If the strong parameter is TRUE, then an E_WARNING level error will be emitted when the fallback rand() implementation is used to fill the remaining random bytes (e.g., when not enough random data was found, initially).

Examples

Example #1 OAuthProvider::generateToken() example


<?php
$p = new OAuthProvider();

$t = $p->generateToken(4);

echo strlen($t),  PHP_EOL;
echo bin2hex($t), PHP_EOL;

?>

The above example will output something similar to:

4
b6a82c27

Notes

Note:
When not enough random data is available to the system, this function will fill the remaining random bytes using the internal PHP rand() implementation.


Be careful when setting the 'strong' parameter to true.



If you system doesn't have enough entropy your script will block which can cause timeouts in other parts of your code.



In my case, the most serious symptom was my script blocking when trying to read from /dev/random and causing a 'MySQL has gone away' error.



Hopefully this saves someone the trouble when deciding to use /dev/random entropy

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