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问Google reCAPTCHA验证器:迭代2
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Code Review用户

提问于 2015-08-11 15:52:23

回答 2查看 1.4K关注 0票数 6

这是我(不到一小时前)关于我的Google reCAPTCHA C#实现的另一篇文章的后续文章：Google reCAPTCHA Validator。

这增加了对错误消息的支持，以便您可以确定reCAPTCHA请求失败的原因(如果返回了错误)。

如果在将ReCaptchaLocationInclude设置为非空列表之前使用ExtraClasses，也会修复错误。

我为错误添加了一个枚举：

/// <summary>
/// Indicates errors that could be returned by the reCAPTCHA API.
/// </summary>
/// <remarks>
/// See: https://developers.google.com/recaptcha/docs/verify
/// </remarks>
[Flags]
public enum ReCaptchaErrors
{
    /// <summary>
    /// No errors occurred.
    /// </summary>
    None = 0x00,
    /// <summary>
    /// The secret parameter is missing.
    /// </summary>
    MissingInputSecret = 0x01,
    /// <summary>
    /// The secret parameter is invalid or malformed.
    /// </summary>
    InvalidInputSecret = 0x02,
    /// <summary>
    /// The response parameter is missing.
    /// </summary>
    MissingInputResponse = 0x04,
    /// <summary>
    /// The response parameter is invalid or malformed.
    /// </summary>
    InvalidInputResponse = 0x08,
}

用于reCAPTCHA响应的类：

/// <summary>
/// This class is used by the <see cref="ReCaptchaValidator"/> to return a proper response to a reCAPTCHA validation request.
/// </summary>
public class ReCaptchaResponse
{
    private bool _Success;
    private ReCaptchaErrors _Errors;

    /// <summary>
    /// Returns a value indicating if the <see cref="ReCaptchaValidator"/> succeeded in validating the reCAPTCHA response or not.
    /// </summary>
    public bool Success { get { return _Success; } }

    /// <summary>
    /// Returns any <see cref="ReCaptchaErrors"/> that occurred during the reCAPTCHA response validation.
    /// </summary>
    public ReCaptchaErrors Errors { get { return _Errors; } }

    /// <summary>
    /// Creates a new <see cref="ReCaptchaResponse"/> from the specified JSON string.
    /// </summary>
    /// <param name="jsonResponse">The JSON string to transform.</param>
    public ReCaptchaResponse(string jsonResponse)
    {
        JavaScriptSerializer jss = new JavaScriptSerializer();
        dynamic deserializedJson = jss.DeserializeObject(jsonResponse);

        _Success = deserializedJson["success"];
        _Errors = ReCaptchaErrors.None;

        if (deserializedJson.ContainsKey("error-codes"))
        {
            foreach (string error in deserializedJson["error-codes"])
            {
                // Our `ReCaptchaErrors` enum contains the exact same strings as the returned `error` text would be, with the following transformations:
                // 1. The words are transformed to PascalCase;
                // 2. The dashes are stripped;
                string[] errorWords = error.Split('-');

                string errorEnumName = "";
                foreach (string errorWord in errorWords)
                    errorEnumName += errorWord[0].ToString().ToUpper() + errorWord.Substring(1);

                _Errors = _Errors | (ReCaptchaErrors)Enum.Parse(typeof(ReCaptchaErrors), errorEnumName);
            }
        }
    }
}

并更新了reCAPTCHA验证器：

/// <summary>
/// This class provides the ability to easily implement Google's reCAPTCHA.
/// </summary>
/// <remarks>
/// See: https://www.google.com/recaptcha/intro/index.html
/// </remarks>
public class ReCaptchaValidator
{
    private const string _HeadScriptInclude = "<script src='https://www.google.com/recaptcha/api.js'></script>";
    private const string _BodyDivInclude = "<div class=\"g-recaptcha %EXTRACLASSES%\" data-sitekey=\"%SITEKEY%\"></div>";
    private const string _ReCaptchaFormCode = "g-recaptcha-response";

    private readonly string _ReCaptchaSecret;
    private readonly string _ReCaptchaSiteKey;
    private readonly List<string> _ExtraClasses = new List<string>();

    /// <summary>
    /// Returns the script to be included in the <code><head></code> of the page.
    /// </summary>
    public string HeadScriptInclude { get { return _HeadScriptInclude; } }

    /// <summary>
    /// Use this to get or set any extra classes that should be added to the <code><div></code> that is created by the <see cref="BodyDivInclude"/>.
    /// </summary>
    public List<string> ExtraClasses { get { return _ExtraClasses; } }

    /// <summary>
    /// Returns the <code><div></code> that should be inserted in the HTML where the reCAPTCHA should go.
    /// </summary>
    /// <remarks>
    /// I'm still not sure if this should be a method or not.
    /// </remarks>
    public string BodyDivInclude { get { return _BodyDivInclude.Replace("%SITEKEY%", _ReCaptchaSiteKey).Replace("%EXTRACLASSES%", string.Join(" ", ExtraClasses)); } }

    /// <summary>
    /// Creates a new instance of the <see cref="ReCaptchaValidator"/>.
    /// </summary>
    /// <param name="reCaptchaSecret">The reCAPTCHA secret.</param>
    /// <param name="reCaptchaSiteKey">The reCAPTCHA site key.</param>
    public ReCaptchaValidator(string reCaptchaSecret, string reCaptchaSiteKey)
    {
        _ReCaptchaSecret = reCaptchaSecret;
        _ReCaptchaSiteKey = reCaptchaSiteKey;
    }

    /// <summary>
    /// Determines if the reCAPTCHA response in a <code>NameValueCollection</code> passed validation.
    /// </summary>
    /// <param name="form">The <code>Request.Form</code> to validate.</param>
    /// <returns>A <see cref="ReCaptchaResponse"/> value indicating the response of the verification.</returns>
    public ReCaptchaResponse Validate(NameValueCollection form)
    {
        string reCaptchaSecret = _ReCaptchaSecret;
        string reCaptchaResponse = form[_ReCaptchaFormCode];

        using (WebClient client = new WebClient())
        {
            // TODO: send user's IP optionally with reCAPTCHA information.
            byte[] response = client.UploadValues("https://www.google.com/recaptcha/api/siteverify",
                                                    new NameValueCollection() { { "secret", reCaptchaSecret }, { "response", reCaptchaResponse } });

            string reCaptchaResult = System.Text.Encoding.UTF8.GetString(response);

            return new ReCaptchaResponse(reCaptchaResult);
        }
    }
}

对于更新的ReCaptchaValidator，我也将ReCaptchaLocationInclude属性更改为BodyDivInclude，以使名称更有意义。我还使ExtraClasses成为一个只获取的List，这样您就不会意外地给它分配一个新的列表。(您只需先使用ReCaptchaValidator.ExtraClasses.Clear()，然后添加新类即可。)

用法：

string reCaptchaSecret = "";
string reCaptchaSiteKey = "";

protected void Page_Load(object sender, EventArgs e)
{
    ReCaptchaValidator rcv = new ReCaptchaValidator(reCaptchaSecret, reCaptchaSiteKey);
    reCaptchaBodyCode.Text = rcv.BodyDivInclude;
    reCaptchaHeadCode.Text = rcv.HeadScriptInclude;
}

protected void CreateUser_Click(object sender, EventArgs e)
{
    ReCaptchaValidator rcv = new ReCaptchaValidator(reCaptchaSecret, reCaptchaSiteKey);
    ReCaptchaResponse reCaptchaResponse = rcv.Validate(Request.Form);

    if (reCaptchaResponse.Success)
    {
        // Please do not comment on code within this block, it is provided as-is by Microsoft and I will not change it unless it is broken (and it is not).

        var manager = Context.GetOwinContext().GetUserManager<ApplicationUserManager>();
        var signInManager = Context.GetOwinContext().Get<ApplicationSignInManager>();
        var user = new ApplicationUser() { UserName = Email.Text, Email = Email.Text };
        IdentityResult result = manager.Create(user, Password.Text);
        if (result.Succeeded)
        {
            // For more information on how to enable account confirmation and password reset please visit http://go.microsoft.com/fwlink/?LinkID=320771
            //string code = manager.GenerateEmailConfirmationToken(user.Id);
            //string callbackUrl = IdentityHelper.GetUserConfirmationRedirectUrl(code, user.Id, Request);
            //manager.SendEmail(user.Id, "Confirm your account", "Please confirm your account by clicking <a href=\"" + callbackUrl + "\">here</a>.");

            signInManager.SignIn(user, isPersistent: false, rememberBrowser: false);
            IdentityHelper.RedirectToReturnUrl(Request.QueryString["ReturnUrl"], Response);
        }
        else
        {
            ErrorMessage.Text = result.Errors.FirstOrDefault();
        }
    }
    else
    {
        ErrorMessage.Text = "We could not verify that you are a human.";
    }
}

这显示了在默认的Web应用程序的注册页面上实现的reCAPTCHA。if (reCaptchaResponse.Success)块中的代码块是页面的默认代码，其余部分是我的修改。请不要评论该代码块内的代码。

最后，前端：

<asp:Content runat="server" ID="HeadContent" ContentPlaceHolderID="HeadContent">
    <%-- This next line is where the <script> tag will end up. --%>
    <asp:Literal ID="reCaptchaHeadCode" runat="server"></asp:Literal>
</asp:Content>

<asp:Content runat="server" ID="BodyContent" ContentPlaceHolderID="MainContent">
    <h2><%: Title %>.</h2>
    <p class="text-danger">
        <asp:Literal runat="server" ID="ErrorMessage" />
    </p>

    <div class="form-horizontal">
        <h4>Create a new account</h4>
        <hr />
        <asp:ValidationSummary runat="server" CssClass="text-danger" />
        <div class="form-group">
            <asp:Label runat="server" AssociatedControlID="Email" CssClass="col-md-2 control-label">Email</asp:Label>
            <div class="col-md-10">
                <asp:TextBox runat="server" ID="Email" CssClass="form-control" TextMode="Email" />
                <asp:RequiredFieldValidator runat="server" ControlToValidate="Email"
                    CssClass="text-danger" ErrorMessage="The email field is required." />
            </div>
        </div>
        <div class="form-group">
            <asp:Label runat="server" AssociatedControlID="Password" CssClass="col-md-2 control-label">Password</asp:Label>
            <div class="col-md-10">
                <asp:TextBox runat="server" ID="Password" TextMode="Password" CssClass="form-control" />
                <asp:RequiredFieldValidator runat="server" ControlToValidate="Password"
                    CssClass="text-danger" ErrorMessage="The password field is required." />
            </div>
        </div>
        <div class="form-group">
            <asp:Label runat="server" AssociatedControlID="ConfirmPassword" CssClass="col-md-2 control-label">Confirm password</asp:Label>
            <div class="col-md-10">
                <asp:TextBox runat="server" ID="ConfirmPassword" TextMode="Password" CssClass="form-control" />
                <asp:RequiredFieldValidator runat="server" ControlToValidate="ConfirmPassword"
                    CssClass="text-danger" Display="Dynamic" ErrorMessage="The confirm password field is required." />
                <asp:CompareValidator runat="server" ControlToCompare="Password" ControlToValidate="ConfirmPassword"
                    CssClass="text-danger" Display="Dynamic" ErrorMessage="The password and confirmation password do not match." />
            </div>
        </div>
        <%-- This next line is where the body code will be filled. --%>
        <asp:Literal ID="reCaptchaBodyCode" runat="server"></asp:Literal>
        <div class="form-group">
            <div class="col-md-offset-2 col-md-10">
                <asp:Button runat="server" OnClick="CreateUser_Click" Text="Register" CssClass="btn btn-default" />
            </div>
        </div>
    </div>
</asp:Content>

请不要过多地评论标记，它提供了更多的上下文，并表明使用实际上是相当简单的。

如果有人使用这个，我不介意，请把这个帖子作为代码的原始源代码。

另外，下面是几张与它一起运行的图片：

captcha

asp.net

validation

polymorphism

回答 2

Code Review用户

回答已采纳

发布于 2015-08-11 22:19:42

在构造函数中拥有可以抛出异常的操作被认为不是一个好形式--它应该简单地验证参数(并且异常抛出可以由您来完成)，然后操作应该在一个方法中进行，比如Process或什么-不是。虽然在ReCaptchaResponse的例子中，它可能是一个简单的静态类：

/// <summary>
/// This class is used by the <see cref="ReCaptchaValidator"/> to return a proper response to a reCAPTCHA validation request.
/// </summary>
public static class ReCaptchaResponse
{
    /// <summary>
    /// Creates a new <see cref="ReCaptchaResponse"/> from the specified JSON string.
    /// </summary>
    /// <param name="jsonResponse">The JSON string to transform.</param>
    /// <param name="errors">Returns any <see cref="ReCaptchaErrors"/> that occurred during the reCAPTCHA response validation.</param>
    /// <returns>Returns a value indicating if the <see cref="ReCaptchaValidator"/> succeeded in validating the reCAPTCHA response or not.</returns>
    public static bool TryParseJson(string jsonResponse, out ReCaptchaErrors errors)
    {
        JavaScriptSerializer jss = new JavaScriptSerializer();
        dynamic deserializedJson = jss.DeserializeObject(jsonResponse);

        bool success = deserializedJson["success"];
        errors = ReCaptchaErrors.None;

        if (deserializedJson.ContainsKey("error-codes"))
        {
            foreach (string error in deserializedJson["error-codes"])
            {
                // Our `ReCaptchaErrors` enum contains the exact same strings as the returned `error` text would be, with the following transformations:
                // 1. The words are transformed to PascalCase;
                // 2. The dashes are stripped;
                string[] errorWords = error.Split('-');

                string errorEnumName = "";
                foreach (string errorWord in errorWords)
                    errorEnumName += errorWord[0].ToString().ToUpper() + errorWord.Substring(1);

                errors = errors | (ReCaptchaErrors)Enum.Parse(typeof(ReCaptchaErrors), errorEnumName);
            }
        }

        return success;
    }
}

可能通过将this添加到第一个参数使其成为一个扩展方法，并且可以这样调用它：

ReCaptchaErrors errors;

var success = reCaptchaResult.TryParseJson(out errors);

票数 4

Code Review用户

发布于 2015-08-11 16:06:38

标志公共枚举ReCaptchaErrors {/ /没有发生错误。/ is = 0x00，/ /缺少秘密参数。/ MissingInputSecret = 0x01，/ /秘密参数无效或格式错误。/ InvalidInputSecret = 0x02，// /缺少响应参数。/ MissingInputResponse = 0x04，/ /响应参数无效或格式错误。/ InvalidInputResponse = 0x08，}

您正在分配这些值，因此enum选项的二进制值是0001、0010、0100、1000等。这样您就可以将多个错误赋值给单个变量，对吗？

如果您使用了位移位，您将更清楚地知道您到底在做什么，如下所示：

[Flags]
public enum ReCaptchaErrors
{
    /// <summary>
    /// No errors occurred.
    /// </summary>
    None = 0,
    /// <summary>
    /// The secret parameter is missing.
    /// </summary>
    MissingInputSecret = 1 << 0,
    /// <summary>
    /// The secret parameter is invalid or malformed.
    /// </summary>
    InvalidInputSecret = 1 << 1,
    /// <summary>
    /// The response parameter is missing.
    /// </summary>
    MissingInputResponse = 1 << 2,
    /// <summary>
    /// The response parameter is invalid or malformed.
    /// </summary>
    InvalidInputResponse = 1 << 3,
}

现在，您不能意外地通过键入0x09而不是0x08来破坏代码，而且很明显，您希望每个标志都是它自己的位。有关更多信息，您可以通过我们自己的@nhgrif阅读这个博客帖子。

票数 4

页面原文内容由Code Review提供。腾讯云小微IT领域专用引擎提供翻译支持

原文链接：

https://codereview.stackexchange.com/questions/100604

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