通过Google reCAPTCHA v3纯JavaScript和PHP验证的联系人表单的简单示例

tldr;跳到底部的代码。

reCAPTCHA相关文档等：

• 创建关键帧：https://www.google.com/recaptcha/admin/create
• 前端集成：https://developers.google.com/recaptcha/docs/v3
• 后端验证：https://developers.google.com/recaptcha/docs/verify

(If谷歌正在听，我们爱你的工作，这将是美妙的，有一些更详细的例子链接到上述网页请。）

概述：

1.从Google获取密钥
1.在html头部加载recaptcha/api.js
1.使用JavaScript劫持表单提交，然后从Google获取令牌
1.将带有令牌的表单提交到服务器
1.从您的网站后端向Google提出请求以验证表单提交
1.解释响应并根据需要继续

**需要注意的是：**success响应参数仅表示验证码是否被成功评估，并不表示提交的内容是否可能是垃圾邮件。

“score”参数是您需要了解的结果。分数越高（0到1之间的数字），提交的内容越有可能是真实的，您可以选择接受的阈值（例如0.5）。

详细说明：

在HTML的头部添加以下行以加载recaptcha api.js代码：

<script src="https://www.google.com/recaptcha/api.js?render=$reCAPTCHA_site_key"></script>

（其中$reCAPTCHA_site_key是您的公共'站点密钥'，我已将其保存在'config.php'文件中。
您需要提交一个令牌（从Google接收，每个表单提交都是唯一的）到您的服务器。我认为最简单的方法是通过POST将其与表单的其余数据沿着发送。为此，我在表单中包含一个隐藏字段，如下所示：

<form id="contactForm" method="post" action="contact">
    <!-- other form inputs -->
    <input type="hidden" id="gRecaptchaResponse" name="gRecaptchaResponse">
    <input type="submit" name="contact_submit" value="Send message">
</form>

(Nb.“contact”是contact.php，但我已经用.htaccess“重写”了URL）
现在我们需要劫持默认表单提交来生成令牌。我们可以在页面加载时生成令牌，但由于令牌的有效期只有两分钟（如果我正确阅读了https://developers.google.com/recaptcha/docs/verify页面），我认为最好在需要将其发送到站点服务器时获取它。
为此，我在关闭表单标签后添加了以下内容：

<script>
    contactForm.addEventListener('submit', event => {
        event.preventDefault()
        validate(contactForm)
    });
</script>

我把validate(form)函数放在结束body标签之前：

function validate(form) {
    //perform optional error checking on form. If no errors then request a token and put it into the hidden field
    getRecaptchaToken(form)
}

//some other (optional) form validation functions

function getRecaptchaToken(form) {
    grecaptcha.ready(function() {
        grecaptcha.execute($reCAPTCHA_site_key, {action: 'contactForm'}).then(function(token) {
            gRecaptchaResponse.value = token //set the value of the hidden field
            form.submit() //submit the form
        });
    });
}

注：

• $reCAPTCHA_site_key是您的公共站点密钥
• action: 'contactForm'在Google reCAPTCHA Jmeter 板中识别此特定表单的提交，并在后端确认它是否符合预期是推荐的额外安全步骤

在主PHP文件中，当收到表单提交时：

//get the IP address of the origin of the submission
$ip = $_SERVER['REMOTE_ADDR'];

//construct the url to send your private Secret Key, token and (optionally) IP address of the form submitter to Google to get a spam rating for the submission (I've saved '$reCAPTCHA_secret_key' in config.php)
$url =  'https://www.google.com/recaptcha/api/siteverify?secret=' . urlencode($reCAPTCHA_secret_key) . '&response=' . urlencode($g_recaptcha_response) . '&remoteip=' . urlencode($ip);

//save the response, e.g. print_r($response) prints { "success": true, "challenge_ts": "2019-07-24T11:19:07Z", "hostname": "your-website-domain.co.uk", "score": 0.9, "action": "contactForm" }
$response = file_get_contents($url);

//decode the response, e.g. print_r($responseKeys) prints Array ( [success] => 1 [challenge_ts] => 2019-07-24T11:19:07Z [hostname] => your-website-domain.co.uk [score] => 0.9 [action] => contactForm )
$responseKeys = json_decode($response, true);

//check if the test was done OK, if the action name is correct and if the score is above your chosen threshold (again, I've saved '$g_recaptcha_allowable_score' in config.php)
if ($responseKeys["success"] && $responseKeys["action"] == 'contactForm') {
    if ($responseKeys["score"] >= $g_recaptcha_allowable_score) {
        //send email with contact form submission data to site owner/ submit to database/ etc
        //redirect to confirmation page or whatever you need to do
    } elseif ($responseKeys["score"] < $g_recaptcha_allowable_score) {
        //failed spam test. Offer the visitor the option to try again or use an alternative method of contact.
    }
} elseif($responseKeys["error-codes"]) { //optional
    //handle errors. See notes below for possible error codes
    //personally I'm probably going to handle errors in much the same way by sending myself a the error code for debugging and offering the visitor the option to try again or use an alternative method of contact
} else {
    //unkown screw up. Again, offer the visitor the option to try again or use an alternative method of contact.
}

注：

• 这是Google响应中的数据（作为JSON对象返回）：

{
     "success": true|false,      // whether this request was a valid reCAPTCHA token for your site
     "score": number             // the score for this request (0.0 - 1.0)
     "action": string            // the action name for this request (important to verify)
     "challenge_ts": timestamp,  // timestamp of the challenge load (ISO format yyyy-MM-dd'T'HH:mm:ssZZ)
     "hostname": string,         // the hostname of the site where the reCAPTCHA was solved
     "error-codes": [...]        // optional
   }

• 以下是可能的错误代码：
• missing-input-secret：缺少机密参数。
• invalid-input-secret：secret参数无效或格式不正确。
• missing-input-response：缺少响应参数。
• invalid-input-response：响应参数无效或格式不正确。
• bad-request：请求无效或格式不正确。
• 超时或重复：响应不再有效;或者太旧或者以前用过。

把这些放在一起：

联系方式.php

<?php  //contact.php

    require_once('config.php');

    //do server-side validation of other form fields

    if (/*form has been submitted and has passed server-side validation of the other form fields*/) {
        $ip = $_SERVER['REMOTE_ADDR'];
        $url =  'https://www.google.com/recaptcha/api/siteverify?secret=' . urlencode($reCAPTCHA_secret_key) . '&response=' . urlencode($g_recaptcha_response) . '&remoteip=' . urlencode($ip);
        $response = file_get_contents($url);
        $responseKeys = json_decode($response, true);

        if ($responseKeys["success"] && $responseKeys["action"] == 'contactForm') {
            if ($responseKeys["score"] >= $g_recaptcha_allowable_score) {
                //send email with contact form submission data to site owner/ submit to database/ etc
                //redirect to confirmation page or whatever you need to do
            } elseif ($responseKeys["score"] < $g_recaptcha_allowable_score) {
                //failed spam test. Offer the visitor the option to try again or use an alternative method of contact.
            }
        } elseif($responseKeys["error-codes"]) { //optional
            //handle errors. See notes below for possible error codes
            //(I handle errors by sending myself an email with the error code for debugging and offering the visitor the option to try again or use an alternative method of contact)
        } else {
            //unkown screw up. Again, offer the visitor the option to try again or use an alternative method of contact.
        }

        exit;

    } else { //(re)display the page with the form

        echo <<<_END

            <!DOCTYPE html>
            <html lang="en">
                <head>
                    <title>Contact | Your website</title>
                    <link rel="stylesheet" href="css/style.css">
                    <script src="https://www.google.com/recaptcha/api.js?render=$reCAPTCHA_site_key"></script>
                </head>
                <body>

                    <!-- header etc -->

                    <form id="contactForm" method="post" action="contact">
                        //other form inputs
                        <input type="hidden" id="gRecaptchaResponse" name="gRecaptchaResponse">
                        <input type="submit" name="contact_submit" value="Send message">
                    </form>
                    <script>
                        contactForm.addEventListener('submit', event => {
                            event.preventDefault()
                            validate(contactForm)
                        });
                    </script>

                    <!-- footer etc -->

                    <script>
                        function validate(form) {
                            //perform optional client-side error checking of the form. If no errors are found then request a token and put it into the hidden field. Finally submit the form.
                            getRecaptchaToken(form)
                        }

                        //some (optional) form field validation functions

                        function getRecaptchaToken(form) {
                            grecaptcha.ready(function() {
                                grecaptcha.execute($reCAPTCHA_site_key, {action: 'contactForm'}).then(function(token) {
                                    gRecaptchaResponse.value = token
                                    form.submit()
                                });
                            });
                        }
                    </script>
                </body>
            </html>

_END;

配置文件php

<?php //config.php

//other site settings

// Google reCAPTCHA v3 keys
// For reducing spam contact form submissions

// Site key (public)
$reCAPTCHA_site_key = 'N0t-a-real-0N3_JHbnbUJ-BLAHBLAH_Blahblah';

// Secret key
$reCAPTCHA_secret_key = 'N0t-a-real-0N3_i77tyYGH7Ty6UfG-blah';

// Min score returned from reCAPTCHA to allow form submission
$g_recaptcha_allowable_score = 0.5; //Number between 0 and 1. You choose this. Setting a number closer to 0 will let through more spam, closer to 1 and you may start to block valid submissions.

试试这个。

<script>
  grecaptcha.ready(function() {
   grecaptcha.execute('YOUR_SITE_KEY', {action: 'MyForm'})
   .then(function(token) {
    console.log(token)
    document.getElementById('g-recaptcha-response').value =    token;
   }); 
  }); 
 </script> 

<form action="verify.php" method="post">
  <input type="hidden" id="g-recaptcha-response" name="g-recaptcha-response">
  <input type="text" name="name" placeholder="Your name" required >
  <input type="email" name="email" placeholder="Your email address" required>
  <input type="submit" name="submit" value="SUBMIT" >
</form>

<html>
    <head>
        <script src='https://www.google.com/recaptcha/api.js?render=6Le7-FkUAAAAADDSsTVBvpoUB5MkesNKgPVemFf-UD'></script>
    </head>
    <body> 
    <script>
    // when form is submit
    $('form').submit(function() { 
        // we stoped it
        event.preventDefault();
        // needs for recaptacha ready
        grecaptcha.ready(function() {
            // do request for recaptcha token
            // response is promise with passed token
            grecaptcha.execute('6Le7-FkUAAAAADDSsTVBvpoUB5MkesNKgPVemFf-UD', {action: 'create_comment'}).then(function(token) {
                // add token to form
                $('form').prepend('<input type="hidden" name="token" value="' + token + '">');
                $('form').prepend('<input type="hidden" name="action" value="create_comment">');
                // submit form now
                $('form').unbind('submit').submit();
            });;
        });
    });

    </script>

    <form action="verify.php" method="post">
        <input type="text" name="name" placeholder="Your name" required >
        <input type="email" name="email" placeholder="Your email address" required>
        <textarea name="message" placeholder="Type your message here...." required></textarea>   

        <input type="submit" name="submit" value="SUBMIT">

    </form>

    </body>

</html>

菲律宾

$token = $_POST['token'];
$secret = 'ur secret';
$action = $_POST['action'];
// now you need do a POST requst to google recaptcha server.
// url: https://www.google.com/recaptcha/api/siteverify.
// with data secret:$secret and response:$token

在代码中的这一点上，您需要向ReCAPTCHA发送一个post请求来验证令牌，如下所示：https://www.google.com/recaptcha/api/siteverify。响应将是一个json对象，带有字段“success”（true/false）和“action”，用于比较（==）和得分（数字从0.0 - 1.0）
https://developers.google.com/recaptcha/docs/v3#api-response.
您还可以为每个请求指定操作名称（create_post、update_post、create_comment...）

下面是一个示例工作代码与演示。
html副代码

<html>
  <head>
    <title>Google recapcha v3 demo - Codeforgeek</title>
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
      <script src="https://www.google.com/recaptcha/api.js?render=put your site key here"></script>
  </head>
  <body>
    <h1>Google reCAPTHA Demo</h1>
    <form id="comment_form" action="form.php" method="post" >
      <input type="email" name="email" placeholder="Type your email" size="40"><br><br>
      <textarea name="comment" rows="8" cols="39"></textarea><br><br>
      <input type="submit" name="submit" value="Post comment"><br><br>
    </form>
      <script>
       // when form is submit
    $('#comment_form').submit(function() {
        // we stoped it
        event.preventDefault();
        var email = $('#email').val();
        var comment = $("#comment").val();
        // needs for recaptacha ready
        grecaptcha.ready(function() {
            // do request for recaptcha token
            // response is promise with passed token
            grecaptcha.execute('put your site key here', {action: 'create_comment'}).then(function(token) {
                // add token to form
                $('#comment_form').prepend('<input type="hidden" name="g-recaptcha-response" value="' + token + '">');
                    $.post("form.php",{email: email, comment: comment, token: token}, function(result) {
                            console.log(result);
                            if(result.success) {
                                    alert('Thanks for posting comment.')
                            } else {
                                    alert('You are spammer ! Get the @$%K out.')
                            }
                    });
            });;
        });
  });
  </script>
  </body>
</html>

PHP代码。

<?php

        $email;$comment;$captcha;
        if(isset($_POST['email'])){
          $email=$_POST['email'];
        }if(isset($_POST['comment'])){
          $comment=$_POST['comment'];
        }if(isset($_POST['token'])){
          $captcha=$_POST['token'];
          }
        if(!$captcha){
          echo '<h2>Please check the the captcha form.</h2>';
          exit;
        }
        $secretKey = "put your secret key here";
        $ip = $_SERVER['REMOTE_ADDR'];

        // post request to server

        $url =  'https://www.google.com/recaptcha/api/siteverify?secret=' . urlencode($secretKey) .  '&response=' . urlencode($captcha);
        $response = file_get_contents($url);
        $responseKeys = json_decode($response,true);
        header('Content-type: application/json');
        if($responseKeys["success"]) {
                echo json_encode(array('success' => 'true'));
        } else {
                echo json_encode(array('success' => 'false'));
        }
?>

它工作正常。
演示：https://demo.codeforgeek.com/recaptcha-v3/
教程：https://codeforgeek.com/2019/02/google-recaptcha-v3-tutorial/

我想给予你一个完整的工作流程来集成recaptchav 3到ASP.NET核心MVC解决方案。
在appsettings.json文件中：

"RecaptchaSettings": {
    "Uri": "https://www.google.com/recaptcha/api/siteverify",
    "SecretKey": "your private key"
    "SiteKey": "your public key",
    "Version": "v3"
  }

在你看来（@razor语法）：

@using Microsoft.Extensions.Configuration
@inject IConfiguration Configuration

<script src="https://www.google.com/recaptcha/api.js?render=@Configuration.GetSection("RecaptchaSettings")["SiteKey"]"></script>

    <script>
        grecaptcha.ready(function () {
            grecaptcha.execute('@Configuration.GetSection("RecaptchaSettings")["SiteKey"]',  { action: 'homepage' })
                .then(function (token) {

                    document.getElementById('g-recaptcha-response').value = token;
                });
        });
    </script>

在你的表格里写上：

<form action="/">
…
<input type="hidden" id="g-recaptcha-response" name="g-recaptcha-response">
…

</form>

我创建了一个简单的方法来管理它：

public async Task<bool> ChallengePassed(string uri, string gRecaptchaResponse, string secret)
        {

            var concUri = uri + "?secret=" + secret + "&response=" + gRecaptchaResponse;

            var request = new HttpRequestMessage(HttpMethod.Get, concUri);
            var res = await _Client.SendAsync(request);

            if (!res.IsSuccessStatusCode)
            {
                return false;
            }

            var data = await res.Content.ReadAsStringAsync();

            dynamic JSONdata = JObject.Parse(data);
            if (JSONdata.success != "true")
            {
                return false;
            }

            return true;
        }

        #endregion

        #region PRIVATE

        #endregion

        #endregion

        #endregion
    }

我只是把它调用到一个控制器中：

//recaptcha validation

    bool isChallengeOk = await _CaptchaVerify.ChallengePassed(_Configuration.GetValue<string>("RecaptchaSettings:Uri"), Request.Form["g-recaptcha-response"], _Configuration.GetValue<string>("RecaptchaSettings:SecretKey"));

请注意，我正在从“_Configuration”对象设置输入参数，该对象表示Startup.cs中配置设置对象的示例。您可以将手动输入参数传递给该方法。
好好享受吧

下面是一个示例php脚本来验证recaptcha，它适用于v2和v3。

<?php
function reCaptcha($recaptcha){
    $secret = "6LenFiQlAAAAANQmiVnxv6MtLmDFSiDeM4CWBjnG";
    $ip = $_SERVER['REMOTE_ADDR'];

    $postvars = array("secret"=>$secret, "response"=>$recaptcha, "remoteip"=>$ip);
    $url = "https://www.google.com/recaptcha/api/siteverify";

    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ch, CURLOPT_TIMEOUT, 10);
    curl_setopt($ch, CURLOPT_POSTFIELDS, $postvars);
    $data = curl_exec($ch);
    curl_close($ch);

    return json_decode($data, true);
}
$recaptcha = $_POST['g-recaptcha-response'];

$res = reCaptcha($recaptcha);

if($res['success']){
    $email = $_POST['email'];
    echo "Success ".$email;
}
else{
    echo "CAPTCHA Failed";
}
?>

你需要发送一个带有secretkey，ip和验证码响应的post请求。
如果您需要有关如何将recapatchav3与示例html和php代码集成的完整教程，请阅读此教程https://geekvortex.com/integrate-invisible-recaptcha-v3-html-php