深入PHP的Email地址邮箱验证的内部函数filter

深入PHP的Email地址邮箱验证的内部函数filter

目录

1、在ThinkPHP 验证邮箱地址的函数。

2、在PHP源代码中查看该函数实现

3、提取之后编写个PHP测试脚本进行测试。

1、在ThinkPHP 验证邮箱地址的函数。

下载了ThinkPHP 5.1源代码，地址：.1-source-code-reading

在里面搜索“email”（忽略大小写），结果如下：

然后分别搜索"filter"和"FILTER_VALIDATE_EMAIL"。

filter的结果太多了，好像没有有用的信息。

在看看FILTER_VALIDATE_EMAIL的结果：

只有一条记录。

然后去Google去搜索“PHP FILTER_VALIDATE_EMAIL”。

去W3school看看使用示例：

<?php$email = "someone@exa mple";if(!filter_var($email, FILTER_VALIDATE_EMAIL)){echo "E-mail is not validn";}else{echo "E-mail is validn";}?>

filter_var是什么函数，怎么直接调用就可以了。在TP5.1中的搜索“filter_var”不存在，那就继续Google。

但都是些用法，没有看到其内部实现。

2、在PHP源代码中查看该函数实现

考虑看看PHP源代码。于是下载了PHP 5.4.45的源代码。下载地址：.4.45.tar.bz2

在源代码中搜索“FILTER_VALIDATE_EMAIL”，很多结果。关键看该函数的内部实现。

FILTER_VALIDATE_EMAIL旁边的标志有个"php_filter_validate_email"，于是继续搜索"php_filter_validate_email"。

打开./ext/filter/logical_filters.c

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 © Michael Rushton 2009-10* /* Feel free to use and redistribute this code. But please keep this copyright notice.**/const char regexp[] = "/^(?!(?:(?:\x22?\x5C[\x00-\x7E]\x22?)|(?:\x22?[^\x5C\x22]\x22?)){255,})(?!(?:(?:\x22?\x5C[\x00-\x7E]\x22?)|(?:\x22?[^\x5C\x22]\x22?)){65,}@)(?:(?:[\x21\x23-\x27\x2A\x2B\x2D\x2F-\x39\x3D\x3F\x5E-\x7E]+)|(?:\x22(?:[\x01-\x08\x0B\x0C\x0E-\x1F\x21\x23-\x5B\x5D-\x7F]|(?:\x5C[\x00-\x7F]))*\x22))(?:\.(?:(?:[\x21\x23-\x27\x2A\x2B\x2D\x2F-\x39\x3D\x3F\x5E-\x7E]+)|(?:\x22(?:[\x01-\x08\x0B\x0C\x0E-\x1F\x21\x23-\x5B\x5D-\x7F]|(?:\x5C[\x00-\x7F]))*\x22)))*@(?:(?:(?!.*[^.]{64,})(?:(?:(?:xn--)?[a-z0-9]+(?:-+[a-z0-9]+)*\.){1,126}){1,}(?:(?:[a-z][a-z0-9]*)|(?:(?:xn--)[a-z0-9]+))(?:-+[a-z0-9]+)*)|(?:\[(?:(?:IPv6:(?:(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){7})|(?:(?!(?:.*[a-f0-9][:\]]){7,})(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){0,5})?::(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){0,5})?)))|(?:(?:IPv6:(?:(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){5}:)|(?:(?!(?:.*[a-f0-9]:){5,})(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){0,3})?::(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){0,3}:)?)))?(?:(?:25[0-5])|(?:2[0-4][0-9])|(?:1[0-9]{2})|(?:[1-9]?[0-9]))(?:\.(?:(?:25[0-5])|(?:2[0-4][0-9])|(?:1[0-9]{2})|(?:[1-9]?[0-9]))){3}))\]))$/iD";pcre       *re = NULL;pcre_extra *pcre_extra = NULL;int preg_options = 0;int         ovector[150]; /* Needs to be a multiple of 3 */int         matches;/* The maximum length of an e-mail address is 320 octets, per RFC 2821. */if (Z_STRLEN_P(value) > 320) {RETURN_VALIDATION_FAILED}re = pcre_get_compiled_regex((char *)regexp, &pcre_extra, &preg_options TSRMLS_CC);if (!re) {RETURN_VALIDATION_FAILED}matches = pcre_exec(re, NULL, Z_STRVAL_P(value), Z_STRLEN_P(value), 0, 0, ovector, 3);/* 0 means that the vector is too small to hold all the captured substring offsets */if (matches < 0) {RETURN_VALIDATION_FAILED}}

从代码中可以看出，首先检查输入的字符长度不能超过320个。然后就用正则表达式匹配了。

这里的正则表达式好像用了ASCII码16进制，看不懂。

3、提取之后编写个PHP测试脚本进行测试。

都是正则表达式应该是通用的编写个测试脚本试试。

$expr = "/^(?!(?:(?:\x22?\x5C[\x00-\x7E]\x22?)|(?:\x22?[^\x5C\x22]\x22?)){255,})(?!(?:(?:\x22?\x5C[\x00-\x7E]\x22?)|(?:\x22?[^\x5C\x22]\x22?)){65,}@)(?:(?:[\x21\x23-\x27\x2A\x2B\x2D\x2F-\x39\x3D\x3F\x5E-\x7E]+)|(?:\x22(?:[\x01-\x08\x0B\x0C\x0E-\x1F\x21\x23-\x5B\x5D-\x7F]|(?:\x5C[\x00-\x7F]))*\x22))(?:\.(?:(?:[\x21\x23-\x27\x2A\x2B\x2D\x2F-\x39\x3D\x3F\x5E-\x7E]+)|(?:\x22(?:[\x01-\x08\x0B\x0C\x0E-\x1F\x21\x23-\x5B\x5D-\x7F]|(?:\x5C[\x00-\x7F]))*\x22)))*@(?:(?:(?!.*[^.]{64,})(?:(?:(?:xn--)?[a-z0-9]+(?:-+[a-z0-9]+)*\.){1,126}){1,}(?:(?:[a-z][a-z0-9]*)|(?:(?:xn--)[a-z0-9]+))(?:-+[a-z0-9]+)*)|(?:\[(?:(?:IPv6:(?:(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){7})|(?:(?!(?:.*[a-f0-9][:\]]){7,})(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){0,5})?::(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){0,5})?)))|(?:(?:IPv6:(?:(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){5}:)|(?:(?!(?:.*[a-f0-9]:){5,})(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){0,3})?::(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){0,3}:)?)))?(?:(?:25[0-5])|(?:2[0-4][0-9])|(?:1[0-9]{2})|(?:[1-9]?[0-9]))(?:\.(?:(?:25[0-5])|(?:2[0-4][0-9])|(?:1[0-9]{2})|(?:[1-9]?[0-9]))){3}))\]))$/iD";if(preg_match($expr,"sw@opensource")){echo "Matchedn";
}else{echo "Invalidedn";
}

运行结果：

将sw@opensource改成sw@opensourcecom，看看结果：

需要进行更多的验证。