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MWCryptRand.php
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1 <?php
27 class MWCryptRand {
28 
36  public static function generateHex( $chars ) {
37  // hex strings are 2x the length of raw binary so we divide the length in half
38  // odd numbers will result in a .5 that leads the generate() being 1 character
39  // short, so we use ceil() to ensure that we always have enough bytes
40  $bytes = ceil( $chars / 2 );
41  // Generate the data and then convert it to a hex string
42  $hex = bin2hex( random_bytes( $bytes ) );
43 
44  // A bit of paranoia here, the caller asked for a specific length of string
45  // here, and it's possible (eg when given an odd number) that we may actually
46  // have at least 1 char more than they asked for. Just in case they made this
47  // call intending to insert it into a database that does truncation we don't
48  // want to give them too much and end up with their database and their live
49  // code having two different values because part of what we gave them is truncated
50  // hence, we strip out any run of characters longer than what we were asked for.
51  return substr( $hex, 0, $chars );
52  }
53 }
static generateHex( $chars)
Generate a run of cryptographically random data and return it in hexadecimal string format...
Definition: MWCryptRand.php:36