Merge "Add support for PHP7 random_bytes in favor of mcrypt_create_iv"

[lhc/web/wiklou.git] / includes / libs / CryptRand.php

diff --git a/includes/libs/CryptRand.php b/includes/libs/CryptRand.php
index 6d18c81..0d3613a 100644 (file)
--- a/includes/libs/CryptRand.php
+++ b/includes/libs/CryptRand.php
@@ -182,7 +182,7 @@ class CryptRand {
                $this->logger->debug( "Clock drift calculation " .
                        "(time-taken=" . ( $timeTaken * 1000 ) . "ms, " .
                        "iterations=$iterations, " .
-                       "time-per-iteration=" . ( $timeTaken / $iterations * 1e6 ) . "us)\n" );
+                       "time-per-iteration=" . ( $timeTaken / $iterations * 1e6 ) . "us)" );
 
                return $data;
        }
@@ -235,8 +235,6 @@ class CryptRand {
         */
        public function generate( $bytes, $forceStrong = false ) {
 
-               $this->logger->debug( "Generating cryptographic random bytes for\n" );
-
                $bytes = floor( $bytes );
                static $buffer = '';
                if ( is_null( $this->strong ) ) {
@@ -244,6 +242,21 @@ class CryptRand {
                        $this->strong = true;
                }
 
+               if ( strlen( $buffer ) < $bytes ) {
+                       // If available make use of PHP 7's random_bytes
+                       // On Linux, getrandom syscall will be used if available.
+                       // On Windows CryptGenRandom will always be used
+                       // On other platforms, /dev/urandom will be used.
+                       // All error situations will throw Exceptions and or Errors
+                       if ( function_exists( 'random_bytes' ) ) {
+                               $rem = $bytes - strlen( $buffer );
+                               $buffer .= random_bytes( $rem );
+                       }
+                       if ( strlen( $buffer ) >= $bytes ) {
+                               $this->strong = true;
+                       }
+               }
+
                if ( strlen( $buffer ) < $bytes ) {
                        // If available make use of mcrypt_create_iv URANDOM source to generate randomness
                        // On unix-like systems this reads from /dev/urandom but does it without any buffering
@@ -255,11 +268,11 @@ class CryptRand {
                                $rem = $bytes - strlen( $buffer );
                                $iv = mcrypt_create_iv( $rem, MCRYPT_DEV_URANDOM );
                                if ( $iv === false ) {
-                                       $this->logger->debug( "mcrypt_create_iv returned false.\n" );
+                                       $this->logger->debug( "mcrypt_create_iv returned false." );
                                } else {
                                        $buffer .= $iv;
                                        $this->logger->debug( "mcrypt_create_iv generated " . strlen( $iv ) .
-                                               " bytes of randomness.\n" );
+                                               " bytes of randomness." );
                                }
                        }
                }
@@ -269,12 +282,12 @@ class CryptRand {
                                $rem = $bytes - strlen( $buffer );
                                $openssl_bytes = openssl_random_pseudo_bytes( $rem, $openssl_strong );
                                if ( $openssl_bytes === false ) {
-                                       $this->logger->debug( "openssl_random_pseudo_bytes returned false.\n" );
+                                       $this->logger->debug( "openssl_random_pseudo_bytes returned false." );
                                } else {
                                        $buffer .= $openssl_bytes;
                                        $this->logger->debug( "openssl_random_pseudo_bytes generated " .
                                                strlen( $openssl_bytes ) . " bytes of " .
-                                               ( $openssl_strong ? "strong" : "weak" ) . " randomness.\n" );
+                                               ( $openssl_strong ? "strong" : "weak" ) . " randomness." );
                                }
                                if ( strlen( $buffer ) >= $bytes ) {
                                        // openssl tells us if the random source was strong, if some of our data was generated
@@ -291,7 +304,7 @@ class CryptRand {
                        $rem = $bytes - strlen( $buffer );
                        if ( !function_exists( 'stream_set_read_buffer' ) && $forceStrong ) {
                                $this->logger->debug( "Was forced to read from /dev/urandom " .
-                                       "without control over the buffer size.\n" );
+                                       "without control over the buffer size." );
                        }
                        // /dev/urandom is generally considered the best possible commonly
                        // available random source, and is available on most *nix systems.
@@ -317,14 +330,14 @@ class CryptRand {
                                $buffer .= $random_bytes;
                                fclose( $urandom );
                                $this->logger->debug( "/dev/urandom generated " . strlen( $random_bytes ) .
-                                       " bytes of randomness.\n" );
+                                       " bytes of randomness." );
 
                                if ( strlen( $buffer ) >= $bytes ) {
                                        // urandom is always strong, set to true if all our data was generated using it
                                        $this->strong = true;
                                }
                        } else {
-                               $this->logger->debug( "/dev/urandom could not be opened.\n" );
+                               $this->logger->debug( "/dev/urandom could not be opened." );
                        }
                }
 
@@ -336,7 +349,7 @@ class CryptRand {
                // out and being used to predict the /randomness/ that follows.
                if ( strlen( $buffer ) < $bytes ) {
                        $this->logger->debug( __METHOD__ .
-                               ": Falling back to using a pseudo random state to generate randomness.\n" );
+                               ": Falling back to using a pseudo random state to generate randomness." );
                }
                while ( strlen( $buffer ) < $bytes ) {
                        $buffer .= MWCryptHash::hmac( $this->randomState(), strval( mt_rand() ) );
@@ -352,7 +365,7 @@ class CryptRand {
                $buffer = substr( $buffer, $bytes );
 
                $this->logger->debug( strlen( $buffer ) .
-                       " bytes of randomness leftover in the buffer.\n" );
+                       " bytes of randomness leftover in the buffer." );
 
                return $generated;
        }