# secure_link_module模块

作用

1. 制定并允许检查请求的链接的真实性以及保护资源免遭未经授权的访问
2. 限制链接生效周期

首先检查nginx是否已安装模块

#nginx -V

输出nginx所有已安装模块，检查是否有ngx_http_secure_link_module

原理图

语法

配置nginx

#vi /etc/nginx/conf.d/cms.conf
    location /sec/ {
        root /soft/xlongwei;
        secure_link $arg_st,$arg_e;
        secure_link_md5 segredo$uri$arg_e; #segredo为密码样例
        if ( $secure_link = "" ) {
                return 402;
        }
        if ( $secure_link = "0" ) {
                return 405;
        }
    }

用php生成测试安全下载链接，由于配置有discuz版的bbs.xlongwei.com，所以直接在discuz目录编辑sec.php即可测试

#vi /soft/discuz/sec.php
<?php
$secret = 'segredo'; // secrets
$path   = "/".$_REQUEST["f"]; // ?f=path
$expire = time()+10; // add ? seconds to be available，这里是10妙内访问有效

$md5 = base64_encode(md5($secret . $path . $expire, true)); // Using binary hashing.
$md5 = strtr($md5, '+/', '-_'); // + and / are considered special characters in URLs, see the wikipedia page linked in references.
$md5 = str_replace('=', '', $md5); // When used in query parameters the base64 padding character is considered special.

$url = "http://cms.xlongwei.com$path?st=$md5&e=$expire";  //安全下载链接可以直接echo输出

$arr = array("url"=>$url, "expire"=>date("Y-m-d H:i:s", $expire), "md5"=>$md5);

echo json_encode($arr); //转成json格式输出也不错
?>

测试访问：http://bbs.xlongwei.com/sec.php?f=sec/test.txt

响应内容中的url：http://cms.xlongwei.com/sec/test.txt?st=FzMATYtf1urcUE5hKf01Bg&e=1437467381

如果超时后再访问会返回405

shell方式生成，http://tool.xlongwei.com/shells/sec.sh

secret=`echo segredo`
path=$1
e=`date -d "+15 seconds" +%s`
str=$secret$path$e
#echo $str
st=`echo -n $str | openssl md5 -binary | openssl base64 | tr +/ -_ | tr -d =`

url="http://cms.xlongwei.com$path?st=$st&e=$e"
echo $url

java方式生成

public class Sec {
	public static String url(String path) {
		String secret="segredo"; //secret
		String e=String.valueOf((System.currentTimeMillis()/1000)+10); //10 seconds
		String md5 = Base64.encodeBase64URLSafeString(DigestUtils.md5(secret+path+e));
		return "http://cms.xlongwei.com"+path+"?st="+md5+"&e="+e;
	}
}

原文链接：https://www.xlongwei.com/detail/15072116