PHP filter_var 和 RFC 5322

Question

PHP 函数 filter_var('bob@example.com', FILTER_VALIDATE_EMAIL) 是否使用标准 RFC 5322 验证电子邮件？

Answer 1

void php_filter_validate_email(PHP_INPUT_FILTER_PARAM_DECL) /* {{{ */
{
    /*
     * The regex below is based on a regex by Michael Rushton.
     * However, it is not identical.  I changed it to only consider routeable
     * addresses as valid.  Michael's regex considers a@b a valid address
     * which conflicts with section 2.3.5 of RFC 5321 which states that:
     *
     *   Only resolvable, fully-qualified domain names (FQDNs) are permitted
     *   when domain names are used in SMTP.  In other words, names that can
     *   be resolved to MX RRs or address (i.e., A or AAAA) RRs (as discussed
     *   in Section 5) are permitted, as are CNAME RRs whose targets can be
     *   resolved, in turn, to MX or address RRs.  Local nicknames or
     *   unqualified names MUST NOT be used.
     *
     * This regex does not handle comments and folding whitespace.  While
     * this is technically valid in an email address, these parts aren't
     * actually part of the address itself.
     *
     * Michael's regex carries this copyright:
     *
     * Copyright Â© Michael Rushton 2009-10
     * http://squiloople.com/
     * Feel free to use and redistribute this code. But please keep this copyright notice.
     *
     */

而 "original" 来源最有可能是：http://squiloople.com/2009/12/20/email-address-validation/

/**
   * Validate an email address using RFC 5322
   *
...

所以，您有一个索赔，并且有人修复了所谓的错误，并且...
...除此之外我一无所知 ;-)

Answer 2

作为 filter_var 使用的正则表达式的作者，我可以确认它没有 全面地 使用 RFC 5322（具体来说，它不允许用于评论和折叠白色 space).

VolkerK 链接到的文章包含更新的验证——包括更准确的 RFC 5322 实现以及 RFC 5321 的实现（在我看来更合适的标准）——但是 filter_var 没有未更新以纳入改进。

PHP filter_var 和 RFC 5322

PHP filter_var and RFC 5322

php

filter-var

rfc5322