* @author Daniel Friesen
* @file
*/
-use Psr\Log\LoggerInterface;
+/**
+ * @deprecated since 1.32, use random_bytes()/random_int()
+ */
class CryptRand {
/**
- * Minimum number of iterations we want to make in our drift calculations.
+ * @deprecated since 1.32, unused
*/
const MIN_ITERATIONS = 1000;
/**
- * Number of milliseconds we want to spend generating each separate byte
- * of the final generated bytes.
- * This is used in combination with the hash length to determine the duration
- * we should spend doing drift calculations.
+ * @deprecated since 1.32, unused
*/
const MSEC_PER_BYTE = 0.5;
/**
- * A boolean indicating whether the previous random generation was done using
- * cryptographically strong random number generator or not.
- */
- protected $strong = null;
-
- /**
- * List of functions to call to generate some random state
+ * Initialize an initial random state based off of whatever we can find
*
- * @var callable[]
- */
- protected $randomFuncs = [];
-
- /**
- * List of files to generate some random state from
+ * @deprecated since 1.32, unused and does nothing
*
- * @var string[]
- */
- protected $randomFiles = [];
-
- /**
- * @var LoggerInterface
- */
- protected $logger;
-
- public function __construct( array $randomFuncs, array $randomFiles, LoggerInterface $logger ) {
- $this->randomFuncs = $randomFuncs;
- $this->randomFiles = $randomFiles;
- $this->logger = $logger;
- }
-
- /**
- * Initialize an initial random state based off of whatever we can find
* @return string
*/
protected function initialRandomState() {
- // $_SERVER contains a variety of unstable user and system specific information
- // It'll vary a little with each page, and vary even more with separate users
- // It'll also vary slightly across different machines
- $state = serialize( $_SERVER );
-
- // Try to gather a little entropy from the different php rand sources
- $state .= rand() . uniqid( mt_rand(), true );
-
- // Include some information about the filesystem's current state in the random state
- $files = $this->randomFiles;
-
- // We know this file is here so grab some info about ourselves
- $files[] = __FILE__;
-
- // We must also have a parent folder, and with the usual file structure, a grandparent
- $files[] = __DIR__;
- $files[] = dirname( __DIR__ );
-
- foreach ( $files as $file ) {
- Wikimedia\suppressWarnings();
- $stat = stat( $file );
- Wikimedia\restoreWarnings();
- if ( $stat ) {
- // stat() duplicates data into numeric and string keys so kill off all the numeric ones
- foreach ( $stat as $k => $v ) {
- if ( is_numeric( $k ) ) {
- unset( $k );
- }
- }
- // The absolute filename itself will differ from install to install so don't leave it out
- $path = realpath( $file );
- if ( $path !== false ) {
- $state .= $path;
- } else {
- $state .= $file;
- }
- $state .= implode( '', $stat );
- } else {
- // The fact that the file isn't there is worth at least a
- // minuscule amount of entropy.
- $state .= '0';
- }
- }
-
- // Try and make this a little more unstable by including the varying process
- // id of the php process we are running inside of if we are able to access it
- if ( function_exists( 'getmypid' ) ) {
- $state .= getmypid();
- }
-
- // If available try to increase the instability of the data by throwing in
- // the precise amount of memory that we happen to be using at the moment.
- if ( function_exists( 'memory_get_usage' ) ) {
- $state .= memory_get_usage( true );
- }
-
- foreach ( $this->randomFuncs as $randomFunc ) {
- $state .= call_user_func( $randomFunc );
- }
-
- return $state;
+ return '';
}
/**
* Randomly hash data while mixing in clock drift data for randomness
*
+ * @deprecated since 1.32, unused and does nothing
+ *
* @param string $data The data to randomly hash.
* @return string The hashed bytes
* @author Tim Starling
*/
protected function driftHash( $data ) {
- // Minimum number of iterations (to avoid slow operations causing the
- // loop to gather little entropy)
- $minIterations = self::MIN_ITERATIONS;
- // Duration of time to spend doing calculations (in seconds)
- $duration = ( self::MSEC_PER_BYTE / 1000 ) * MWCryptHash::hashLength();
- // Create a buffer to use to trigger memory operations
- $bufLength = 10000000;
- $buffer = str_repeat( ' ', $bufLength );
- $bufPos = 0;
-
- // Iterate for $duration seconds or at least $minIterations number of iterations
- $iterations = 0;
- $startTime = microtime( true );
- $currentTime = $startTime;
- while ( $iterations < $minIterations || $currentTime - $startTime < $duration ) {
- // Trigger some memory writing to trigger some bus activity
- // This may create variance in the time between iterations
- $bufPos = ( $bufPos + 13 ) % $bufLength;
- $buffer[$bufPos] = ' ';
- // Add the drift between this iteration and the last in as entropy
- $nextTime = microtime( true );
- $delta = (int)( ( $nextTime - $currentTime ) * 1000000 );
- $data .= $delta;
- // Every 100 iterations hash the data and entropy
- if ( $iterations % 100 === 0 ) {
- $data = sha1( $data );
- }
- $currentTime = $nextTime;
- $iterations++;
- }
- $timeTaken = $currentTime - $startTime;
- $data = MWCryptHash::hash( $data );
-
- $this->logger->debug( "Clock drift calculation " .
- "(time-taken=" . ( $timeTaken * 1000 ) . "ms, " .
- "iterations=$iterations, " .
- "time-per-iteration=" . ( $timeTaken / $iterations * 1e6 ) . "us)" );
-
- return $data;
+ return '';
}
/**
* Return a rolling random state initially build using data from unstable sources
+ *
+ * @deprecated since 1.32, unused and does nothing
+ *
* @return string A new weak random state
*/
protected function randomState() {
- static $state = null;
- if ( is_null( $state ) ) {
- // Initialize the state with whatever unstable data we can find
- // It's important that this data is hashed right afterwards to prevent
- // it from being leaked into the output stream
- $state = MWCryptHash::hash( $this->initialRandomState() );
- }
- // Generate a new random state based on the initial random state or previous
- // random state by combining it with clock drift
- $state = $this->driftHash( $state );
-
- return $state;
+ return '';
}
/**
* random bytes generation in the previously run generate* call
* was cryptographically strong.
*
- * @return bool Returns true if the source was strong, false if not.
+ * @deprecated since 1.32, always returns true
+ *
+ * @return bool Always true
*/
public function wasStrong() {
- if ( is_null( $this->strong ) ) {
- throw new RuntimeException( __METHOD__ . ' called before generation of random data' );
- }
-
- return $this->strong;
+ return true;
}
/**
- * Generate a run of (ideally) cryptographically random data and return
+ * Generate a run of cryptographically random data and return
* it in raw binary form.
* You can use CryptRand::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 function generate( $bytes, $forceStrong = false ) {
+ public function generate( $bytes ) {
$bytes = floor( $bytes );
- static $buffer = '';
- if ( is_null( $this->strong ) ) {
- // Set strength to false initially until we know what source data is coming from
- $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.
- // Avoids polyfills from before php 7.0
- // All error situations will throw Exceptions and or Errors
- if ( PHP_VERSION_ID >= 70000
- || ( defined( 'HHVM_VERSION_ID' ) && HHVM_VERSION_ID >= 31101 )
- ) {
- $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
- // and bypasses openbasedir restrictions, so it's preferable to reading directly
- // On Windows starting in PHP 5.3.0 Windows' native CryptGenRandom is used to generate
- // entropy so this is also preferable to just trying to read urandom because it may work
- // on Windows systems as well.
- if ( function_exists( 'mcrypt_create_iv' ) ) {
- $rem = $bytes - strlen( $buffer );
- $iv = mcrypt_create_iv( $rem, MCRYPT_DEV_URANDOM );
- if ( $iv === false ) {
- $this->logger->debug( "mcrypt_create_iv returned false." );
- } else {
- $buffer .= $iv;
- $this->logger->debug( "mcrypt_create_iv generated " . strlen( $iv ) .
- " bytes of randomness." );
- }
- }
- }
-
- if ( strlen( $buffer ) < $bytes ) {
- if ( function_exists( 'openssl_random_pseudo_bytes' ) ) {
- $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." );
- } else {
- $buffer .= $openssl_bytes;
- $this->logger->debug( "openssl_random_pseudo_bytes generated " .
- strlen( $openssl_bytes ) . " bytes of " .
- ( $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
- // using it use it's say on whether the randomness is strong
- $this->strong = !!$openssl_strong;
- }
- }
- }
-
- // Only read from urandom if we can control the buffer size or were passed forceStrong
- if ( strlen( $buffer ) < $bytes &&
- ( function_exists( 'stream_set_read_buffer' ) || $forceStrong )
- ) {
- $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." );
- }
- // /dev/urandom is generally considered the best possible commonly
- // available random source, and is available on most *nix systems.
- Wikimedia\suppressWarnings();
- $urandom = fopen( "/dev/urandom", "rb" );
- Wikimedia\restoreWarnings();
-
- // Attempt to read all our random data from urandom
- // php's fread always does buffered reads based on the stream's chunk_size
- // so in reality it will usually read more than the amount of data we're
- // asked for and not storing that risks depleting the system's random pool.
- // If stream_set_read_buffer is available set the chunk_size to the amount
- // of data we need. Otherwise read 8k, php's default chunk_size.
- if ( $urandom ) {
- // php's default chunk_size is 8k
- $chunk_size = 1024 * 8;
- if ( function_exists( 'stream_set_read_buffer' ) ) {
- // If possible set the chunk_size to the amount of data we need
- stream_set_read_buffer( $urandom, $rem );
- $chunk_size = $rem;
- }
- $random_bytes = fread( $urandom, max( $chunk_size, $rem ) );
- $buffer .= $random_bytes;
- fclose( $urandom );
- $this->logger->debug( "/dev/urandom generated " . strlen( $random_bytes ) .
- " 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." );
- }
- }
-
- // If we cannot use or generate enough data from a secure source
- // use this loop to generate a good set of pseudo random data.
- // This works by initializing a random state using a pile of unstable data
- // and continually shoving it through a hash along with a variable salt.
- // We hash the random state with more salt to avoid the state from leaking
- // 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." );
- }
- while ( strlen( $buffer ) < $bytes ) {
- $buffer .= MWCryptHash::hmac( $this->randomState(), strval( mt_rand() ) );
- // This code is never really cryptographically strong, if we use it
- // at all, then set strong to false.
- $this->strong = false;
- }
-
- // Once the buffer has been filled up with enough random data to fulfill
- // the request shift off enough data to handle the request and leave the
- // unused portion left inside the buffer for the next request for random data
- $generated = substr( $buffer, 0, $bytes );
- $buffer = substr( $buffer, $bytes );
-
- $this->logger->debug( strlen( $buffer ) .
- " bytes of randomness leftover in the buffer." );
-
- return $generated;
+ return random_bytes( $bytes );
}
/**
- * 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 CryptRand::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 function generateHex( $chars, $forceStrong = false ) {
- // 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( $this->generate( $bytes, $forceStrong ) );
-
- // 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 );
+ public function generateHex( $chars ) {
+ return MWCryptRand::generateHex( $chars );
}
}
dépôts / lhc / web / wiklou.git / blobdiff