配置

server {
    listen        8080;
    secure_link $arg_md5,$arg_expires;
    secure_link_md5 "$secure_link_expires$uri secret_key";

    if ($secure_link = ""){
        return 403;
    }

    if ($secure_link = "0"){
        return 410;
    }

    root E:\\Collection\\;
}

实现

阅读文章和文档。

var link = new Uri("http://localhost:8080/sample.png");
var expires = new DateTimeOffset(new DateTime(2021, 5, 11)).ToUnixTimeSeconds();
string str = $"{expires}{link.LocalPath} secret_key";
Console.WriteLine(str);
var md5 = MD5.Create();
var md5Str = Convert.ToBase64String(md5.ComputeHash(Encoding.UTF8.GetBytes(str)))
    .Replace(‘+‘, ‘-‘)
    .Replace(‘/‘, ‘_‘)
    .Replace("=", "");

Console.WriteLine($"{link}?md5={md5Str}&expires={expires}");

输出

1620662400/sample.png secret_key
http://localhost:8080/sample.png?md5=rBlDE51CM1v5dc6Wr7my9Q&expires=1620662400

nginx secure_link_md5 计算md5 C#实现