Merge "Set MW_INSTALL_PATH in Maintenance.php"

[lhc/web/wiklou.git] / includes / utils / MWCryptRand.php

diff --git a/includes/utils/MWCryptRand.php b/includes/utils/MWCryptRand.php
index 5818958..673586d 100644 (file)
--- a/includes/utils/MWCryptRand.php
+++ b/includes/utils/MWCryptRand.php
@@ -24,56 +24,30 @@
  * @file
  */
 
-use MediaWiki\MediaWikiServices;
-
 class MWCryptRand {
-       /**
-        * @return CryptRand
-        */
-       protected static function singleton() {
-               return MediaWikiServices::getInstance()->getCryptRand();
-       }
 
        /**
-        * Return a boolean indicating whether or not the source used for cryptographic
-        * random bytes generation in the previously run generate* call
-        * was cryptographically strong.
-        *
-        * @return bool Returns true if the source was strong, false if not.
-        */
-       public static function wasStrong() {
-               return self::singleton()->wasStrong();
-       }
-
-       /**
-        * Generate a run of (ideally) cryptographically random data and return
-        * it in raw binary form.
-        * You can use MWCryptRand::wasStrong() if you wish to know if the source used
-        * was cryptographically strong.
-        *
-        * @param int $bytes The number of bytes of random data to generate
-        * @param bool $forceStrong Pass true if you want generate to prefer cryptographically
-        *                          strong sources of entropy even if reading from them may steal
-        *                          more entropy from the system than optimal.
-        * @return string Raw binary random data
-        */
-       public static function generate( $bytes, $forceStrong = false ) {
-               return self::singleton()->generate( $bytes, $forceStrong );
-       }
-
-       /**
-        * Generate a run of (ideally) cryptographically random data and return
+        * Generate a run of cryptographically random data and return
         * it in hexadecimal string format.
-        * You can use MWCryptRand::wasStrong() if you wish to know if the source used
-        * was cryptographically strong.
         *
         * @param int $chars The number of hex chars of random data to generate
-        * @param bool $forceStrong Pass true if you want generate to prefer cryptographically
-        *                          strong sources of entropy even if reading from them may steal
-        *                          more entropy from the system than optimal.
         * @return string Hexadecimal random data
         */
-       public static function generateHex( $chars, $forceStrong = false ) {
-               return self::singleton()->generateHex( $chars, $forceStrong );
+       public static function generateHex( $chars ) {
+               // hex strings are 2x the length of raw binary so we divide the length in half
+               // odd numbers will result in a .5 that leads the generate() being 1 character
+               // short, so we use ceil() to ensure that we always have enough bytes
+               $bytes = ceil( $chars / 2 );
+               // Generate the data and then convert it to a hex string
+               $hex = bin2hex( random_bytes( $bytes ) );
+
+               // A bit of paranoia here, the caller asked for a specific length of string
+               // here, and it's possible (eg when given an odd number) that we may actually
+               // have at least 1 char more than they asked for. Just in case they made this
+               // call intending to insert it into a database that does truncation we don't
+               // want to give them too much and end up with their database and their live
+               // code having two different values because part of what we gave them is truncated
+               // hence, we strip out any run of characters longer than what we were asked for.
+               return substr( $hex, 0, $chars );
        }
 }