libxml_disable_entity_loader

(PHP 5 >= 5.2.11, PHP 7, PHP 8)

libxml_disable_entity_loader — Disable the ability to load external entities

警告

本函数已自 PHP 8.0.0 起被废弃。强烈建议不要依赖本函数。

说明

#[\Deprecated]
libxml_disable_entity_loader(bool $disable = true): bool

Disable/enable the ability to load external entities. Note that disabling the loading of external entities may cause general issues with loading XML documents.

As of libxml 2.9.0 entity substitution is disabled by default, so there is no need to disable the loading of external entities, unless there is the need to resolve internal entity references with LIBXML_NOENT, LIBXML_DTDVALID, or LIBXML_DTDLOAD. Generally, it is preferable to use libxml_set_external_entity_loader() to suppress loading of external entities. The LIBXML_NO_XXE constant can be used to prevent this as well (only available in Libxml >= 2.13.0, as of PHP 8.4.0).

参数

disable: Disable (true) or enable (false) libxml extensions (such as DOM, XMLWriter and XMLReader) to load external entities.

返回值

Returns the previous value.

更新日志

版本	说明
8.0.0	This function has been deprecated.

参见

libxml_use_internal_errors() - Disable libxml errors and allow user to fetch error information as needed
libxml_set_external_entity_loader() - Changes the default external entity loader
The LIBXML_NOENT constant
The LIBXML_DTDVALID constant
The LIBXML_NO_XXE constant

发现了问题？

了解如何改进此页面 • 提交拉取请求 • 报告一个错误

＋添加备注

用户贡献的备注 6 notes

down

suconghou at gmail dot com ¶

4 years ago

In PHP 8.0 and later, PHP uses libxml versions from 2.9.0, libxml_disable_entity_loader is deprecated.
so it is now safe to remove all `libxml_disable_entity_loader` calls on php8

if you want Backwards Compatibility

use this snippet

if (\PHP_VERSION_ID < 80000) {
    libxml_disable_entity_loader(true);
}

down

vavra at 602 dot cz ¶

7 years ago

If is called 
libxml_disable_entity_loader(true);

, it causes that new SoapClient(.) fails with

SOAP-ERROR: Parsing WSDL: Couldn't load from 'D:\path/dm_operations.wsdl' : failed to load external entity "D:\path/dm_operations.wsdl

because this wsdl imports a xsd as an another external file.
Tested on php 7.1.12, win x64.

down

editor at geekkb.com ¶

1 year ago

There is an extra \ should be deleted before PHP_VERSION_ID in the code which suconghou posted 2 years ago.

if (PHP_VERSION_ID < 80000) {
    libxml_disable_entity_loader(true);
}

down

phofstetter at sensational dot ch ¶

11 years ago

Be mindful that this also disables url loading in simplexml_load_file() and likely other libxml based functions that deal with URLs

down

simonsimcity ¶

12 years ago

Using this function you can prevent a vulnerable to Local and Remote File Inclusion attacks.

You'll see it in an example where I load and validate the following string:

<!DOCTYPE scan [<!ENTITY test SYSTEM "php://filter/read=convert.base64-encode/resource=/etc/passwd">]>
<scan>&test;</scan>

One way to prevent that the file in given back is to set this value to 0.
Please take a closer look at the release of symfony 2.0.11

down

-3

brendan at bloodbone dot ws ¶

10 years ago

This also seems to have an impact on <xsl:import /> statements if this is applied when loading XSLT for the XSLTProcessor class.

＋添加备注

备份地址：http://www.lvesu.com/blog/php/function.libxml-disable-entity-loader.php