X-Git-Url: http://git.heureux-cyclage.org/?a=blobdiff_plain;ds=sidebyside;f=includes%2FGlobalFunctions.php;h=11388e8607f9bbd9ce6905dbe5dfebfd2d60a56f;hb=17cc78767ab099f9d00d267f230be81c202b1795;hp=ddea620b815dcb637bcd2686bd2e0a8f037437a3;hpb=db6b2cb3c252479ed6e9cf80100c3802528bd45f;p=lhc%2Fweb%2Fwiklou.git

diff --git a/includes/GlobalFunctions.php b/includes/GlobalFunctions.php
index ddea620b81..11388e8607 100644
--- a/includes/GlobalFunctions.php
+++ b/includes/GlobalFunctions.php
@@ -102,19 +102,30 @@ if ( !function_exists( 'gzdecode' ) ) {
 }
 
 // hash_equals function only exists in PHP >= 5.6.0
+// http://php.net/hash_equals
 if ( !function_exists( 'hash_equals' ) ) {
 	/**
-	 * Check whether a user-provided string is equal to a fixed-length secret without
-	 * revealing bytes of the secret through timing differences.
+	 * Check whether a user-provided string is equal to a fixed-length secret string
+	 * without revealing bytes of the secret string through timing differences.
 	 *
-	 * This timing guarantee -- that a partial match takes the same time as a complete
-	 * mismatch -- is why this function is used in some security-sensitive parts of the code.
-	 * For example, it shouldn't be possible to guess an HMAC signature one byte at a time.
+	 * The usual way to compare strings (PHP's === operator or the underlying memcmp()
+	 * function in C) is to compare corresponding bytes and stop at the first difference,
+	 * which would take longer for a partial match than for a complete mismatch. This
+	 * is not secure when one of the strings (e.g. an HMAC or token) must remain secret
+	 * and the other may come from an attacker. Statistical analysis of timing measurements
+	 * over many requests may allow the attacker to guess the string's bytes one at a time
+	 * (and check his guesses) even if the timing differences are extremely small.
+	 *
+	 * When making such a security-sensitive comparison, it is essential that the sequence
+	 * in which instructions are executed and memory locations are accessed not depend on
+	 * the secret string's value. HOWEVER, for simplicity, we do not attempt to minimize
+	 * the inevitable leakage of the string's length. That is generally known anyway as
+	 * a chararacteristic of the hash function used to compute the secret value.
 	 *
 	 * Longer explanation: http://www.emerose.com/timing-attacks-explained
 	 *
 	 * @codeCoverageIgnore
-	 * @param string $known_string Fixed-length secret to compare against
+	 * @param string $known_string Fixed-length secret string to compare against
 	 * @param string $user_string User-provided string
 	 * @return bool True if the strings are the same, false otherwise
 	 */
@@ -134,14 +145,14 @@ if ( !function_exists( 'hash_equals' ) ) {
 			return false;
 		}
 
-		// Note that we do one thing PHP doesn't: try to avoid leaking information about
-		// relative lengths of $known_string and $user_string, and of multiple $known_strings.
-		// However, lengths may still inevitably leak through, for example, CPU cache misses.
 		$known_string_len = strlen( $known_string );
-		$user_string_len = strlen( $user_string );
-		$result = $known_string_len ^ $user_string_len;
-		for ( $i = 0; $i < $user_string_len; $i++ ) {
-			$result |= ord( $known_string[$i % $known_string_len] ) ^ ord( $user_string[$i] );
+		if ( $known_string_len !== strlen( $user_string ) ) {
+			return false;
+		}
+
+		$result = 0;
+		for ( $i = 0; $i < $known_string_len; $i++ ) {
+			$result |= ord( $known_string[$i] ) ^ ord( $user_string[$i] );
 		}
 
 		return ( $result === 0 );
@@ -1407,7 +1418,7 @@ function wfGetLangObj( $langcode = false ) {
  *
  * This function replaces all old wfMsg* functions.
  *
- * @param string $key Message key
+ * @param string|string[] $key Message key, or array of keys
  * @param mixed $params,... Normal message parameters
  * @return Message
  *
@@ -2975,7 +2986,9 @@ function wfShellExec( $cmd, &$retval = null, $environ = array(),
  * function, as all the arguments to wfShellExec can become unwieldy.
  *
  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
- * @param string $cmd Command line, properly escaped for shell.
+ * @param string|string[] $cmd If string, a properly shell-escaped command line,
+ *   or an array of unescaped arguments, in which case each value will be escaped
+ *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
  * @param null|mixed &$retval Optional, will receive the program's exit code.
  *   (non-zero is usually failure)
  * @param array $environ Optional environment variables which should be
@@ -3179,10 +3192,10 @@ function wfDiff( $before, $after, $params = '-u' ) {
 
 	// Kill the --- and +++ lines. They're not useful.
 	$diff_lines = explode( "\n", $diff );
-	if ( strpos( $diff_lines[0], '---' ) === 0 ) {
+	if ( isset( $diff_lines[0] ) && strpos( $diff_lines[0], '---' ) === 0 ) {
 		unset( $diff_lines[0] );
 	}
-	if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
+	if ( isset( $diff_lines[1] ) && strpos( $diff_lines[1], '+++' ) === 0 ) {
 		unset( $diff_lines[1] );
 	}
 
@@ -3366,7 +3379,10 @@ function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1,
 	);
 
 	if ( extension_loaded( 'gmp' ) && ( $engine == 'auto' || $engine == 'gmp' ) ) {
-		$result = gmp_strval( gmp_init( $input, $sourceBase ), $destBase );
+		// Removing leading zeros works around broken base detection code in
+		// some PHP versions (see <https://bugs.php.net/bug.php?id=50175> and
+		// <https://bugs.php.net/bug.php?id=55398>).
+		$result = gmp_strval( gmp_init( ltrim( $input, '0' ), $sourceBase ), $destBase );
 	} elseif ( extension_loaded( 'bcmath' ) && ( $engine == 'auto' || $engine == 'bcmath' ) ) {
 		$decimal = '0';
 		foreach ( str_split( strtolower( $input ) ) as $char ) {
@@ -3749,46 +3765,77 @@ function wfGetNull() {
 }
 
 /**
- * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
- * and waiting for it to go down, this waits for the slaves to catch up to the
- * master position. Use this when updating very large numbers of rows, as
- * in maintenance scripts, to avoid causing too much lag.  Of course, this is
- * a no-op if there are no slaves.
+ * Waits for the slaves to catch up to the master position
+ *
+ * Use this when updating very large numbers of rows, as in maintenance scripts,
+ * to avoid causing too much lag. Of course, this is a no-op if there are no slaves.
+ *
+ * By default this waits on the main DB cluster of the current wiki.
+ * If $cluster is set to "*" it will wait on all DB clusters, including
+ * external ones. If the lag being waiting on is caused by the code that
+ * does this check, it makes since to use $ifWritesSince, particularly if
+ * cluster is "*", to avoid excess overhead.
+ *
+ * Never call this function after a big DB write that is still in a transaction.
+ * This only makes sense after the possible lag inducing changes were committed.
  *
  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
+ * @param int|null $timeout Max wait time. Default: 1 day (cli), ~10 seconds (web)
  * @return bool Success (able to connect and no timeouts reached)
  */
-function wfWaitForSlaves( $ifWritesSince = false, $wiki = false, $cluster = false ) {
+function wfWaitForSlaves(
+	$ifWritesSince = null, $wiki = false, $cluster = false, $timeout = null
+) {
 	// B/C: first argument used to be "max seconds of lag"; ignore such values
-	$ifWritesSince = ( $ifWritesSince > 1e9 ) ? $ifWritesSince : false;
+	$ifWritesSince = ( $ifWritesSince > 1e9 ) ? $ifWritesSince : null;
 
-	if ( $cluster !== false ) {
-		$lb = wfGetLBFactory()->getExternalLB( $cluster );
-	} else {
-		$lb = wfGetLB( $wiki );
+	if ( $timeout === null ) {
+		$timeout = ( PHP_SAPI === 'cli' ) ? 86400 : 10;
 	}
 
-	// bug 27975 - Don't try to wait for slaves if there are none
-	// Prevents permission error when getting master position
-	if ( $lb->getServerCount() > 1 ) {
-		if ( $ifWritesSince && !$lb->hasMasterConnection() ) {
-			return true; // assume no writes done
-		}
-		$dbw = $lb->getConnection( DB_MASTER, array(), $wiki );
-		if ( $ifWritesSince && $dbw->lastDoneWrites() < $ifWritesSince ) {
-			return true; // no writes since the last wait
+	// Figure out which clusters need to be checked
+	$lbs = array();
+	if ( $cluster === '*' ) {
+		wfGetLBFactory()->forEachLB( function( LoadBalancer $lb ) use ( &$lbs ) {
+			$lbs[] = $lb;
+		} );
+	} elseif ( $cluster !== false ) {
+		$lbs[] = wfGetLBFactory()->getExternalLB( $cluster );
+	} else {
+		$lbs[] = wfGetLB( $wiki );
+	}
+
+	// Get all the master positions of applicable DBs right now.
+	// This can be faster since waiting on one cluster reduces the
+	// time needed to wait on the next clusters.
+	$masterPositions = array_fill( 0, count( $lbs ), false );
+	foreach ( $lbs as $i => $lb ) {
+		// bug 27975 - Don't try to wait for slaves if there are none
+		// Prevents permission error when getting master position
+		if ( $lb->getServerCount() > 1 ) {
+			if ( $ifWritesSince && !$lb->hasMasterConnection() ) {
+				continue; // assume no writes done
+			}
+			$dbw = $lb->getConnection( DB_MASTER, array(), $wiki );
+			if ( $ifWritesSince && $dbw->lastDoneWrites() < $ifWritesSince ) {
+				continue; // no writes since the last wait
+			}
+			$masterPositions[$i] = $dbw->getMasterPos();
 		}
-		$pos = $dbw->getMasterPos();
-		// The DBMS may not support getMasterPos() or the whole
-		// load balancer might be fake (e.g. $wgAllDBsAreLocalhost).
-		if ( $pos !== false ) {
-			return $lb->waitForAll( $pos, PHP_SAPI === 'cli' ? 86400 : null );
+	}
+
+	$ok = true;
+	foreach ( $lbs as $i => $lb ) {
+		if ( $masterPositions[$i] ) {
+			// The DBMS may not support getMasterPos() or the whole
+			// load balancer might be fake (e.g. $wgAllDBsAreLocalhost).
+			$ok = $lb->waitForAll( $masterPositions[$i], $timeout ) && $ok;
 		}
 	}
 
-	return true;
+	return $ok;
 }
 
 /**