Fix bug #61660: bin2hex(hex2bin($data)) != $data

If the input data has an odd length a warning is thrown and false is returned.

Author: nikic

NEWS

@@ -9,6 +9,7 @@ PHP                                                                        NEWS
   . "Connection: close" instead of "Connection: closed" (Gustavo)
 
 - Core:
+  . Fixed bug #61660 (bin2hex(hex2bin($data)) != $data). (Nikita Popov)
   . Fixed bug #61650 (ini parser crashes when using ${xxxx} ini variables
     (without apache2)). (Laruence)
   . Fixed bug #61605 (header_remove() does not remove all headers). (Laruence)

ext/standard/string.c

@@ -266,6 +266,11 @@ PHP_FUNCTION(hex2bin)
 		return;
 	}
 
+	if (datalen % 2 != 0) {
+		php_error_docref(NULL TSRMLS_CC, E_WARNING, "Hexadecimal input string must have an even length");
+		RETURN_FALSE;
+	}
+
 	result = php_hex2bin((unsigned char *)data, datalen, &newlen);
 
 	if (!result) {

ext/standard/tests/strings/bug61660.phpt

@@ -0,0 +1,11 @@
+--TEST--
+Bug #61660: bin2hex(hex2bin($data)) != $data
+--FILE--
+<?php
+
+var_dump(hex2bin('123'));
+
+?>
+--EXPECTF--
+Warning: hex2bin(): Hexadecimal input string must have an even length in %s on line %d
+bool(false)