captcha

问题 I have login form that uses captcha verification. I am having trouble writing validation in my php file that will get error if captcha is not correctly inputted. Currently I have validation that if no captcha is inputted it shows error, but I when I type some wrong captcha the login proceeds and logs in user on to site. Here is my code and any help is appreciated. login.php <?php session_start(); require 'connection.php'; $username_error = ""; $password_error = ""; $captcha_error = ""; if($

问题 can somebody sent me a link, or to provide me an example with pure Javascript/jQuery captcha. Because I can see a lots of examples with PHP/C# ... back end. But I need just Javascript . Thanks !! 回答1: I think this is not a good idea, because if validation is made in client (js), somebody can make a script to read the correct answer. EDIT Anyway, if you want a useless captcha, you can play with this: See in jsfiddle. HTML Pseudo-Human check. <br/>How much is: <input type="text" id="a"/> <br/

问题 This post refers to Google ReCaptcha v2 (not the latest version) Recently Google introduced a simplified "captcha" verification system (video) that enables users to pass the "captcha" just by clicking on it. But how can it differentiate a bot from a person just by a click? As per this answer, (assuming a similar implementation), at first "recaptcha" generates a hidden key and attaches it to a hidden input element and also lazily renders a check box (not an actual check box input but a div )

问题 This post refers to Google ReCaptcha v2 (not the latest version) Recently Google introduced a simplified "captcha" verification system (video) that enables users to pass the "captcha" just by clicking on it. But how can it differentiate a bot from a person just by a click? As per this answer, (assuming a similar implementation), at first "recaptcha" generates a hidden key and attaches it to a hidden input element and also lazily renders a check box (not an actual check box input but a div )

问题 I have this code: captcha.php: session_start(); class Captcha { protected $code; protected $width = 35; protected $height = 150; function __construct() { $this->code = substr(sha1(mt_rand()), 17, 6); $_SESSION['captcha'] = $this->code; } function getCode(){ return $this->code; } function showImage() { // here comes the code that builds the image. // it works fine! } } $image = new Captcha(); $image->showImage(); And in my login form I have: <iframe src="includes/captcha.php" frameborder="0"

问题 I want to create an script for creating captcha images similar to the captcha used by some popular websites like in the image below. I have created the script which generates captcha but I want to make it somewhat like below And I want to add those random lines in the image but I cant figure our how can I achieve it,Please suggest how to do it in PHP.or any similar open-source project I can reference to. 回答1: The below code gives you a starting point to do what you want. Note that this gives

问题 I want to create an script for creating captcha images similar to the captcha used by some popular websites like in the image below. I have created the script which generates captcha but I want to make it somewhat like below And I want to add those random lines in the image but I cant figure our how can I achieve it,Please suggest how to do it in PHP.or any similar open-source project I can reference to. 回答1: The below code gives you a starting point to do what you want. Note that this gives

问题 I'm working with Yodlee MFAs, in this case, captcha, and I'm wondering how to render the image field from this JSON response: { "isMessageAvailable":true, "fieldInfo":{ "responseFieldType":"text", "imageFieldType":"image", "image":[ 66, 77, 58, 116, 0, 0, 0, 0, 0, 0, 54, 0, 0, 0, 40, 0, 0, 0, -91, 0, 0, 0, 45, 0, 0, 0, 1, 0, 32, 0, 0, 0, 0, 0, 4, 116, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, -1, -1, 0, -1, -1, -1, 0, -1, -1, -1, 0, -1, -1, -1, 0, -1, -1, -1, 0, -1, -5, -1, 0,

问题 Is Google reCaptcha v2 supported in Internet Explorer 8? If not is there any suitable Internet Explorer 8 compatible captchas? I am seeing a issue where the reCaptcha code is trying to use the method getContext. Object doesn't support property or method 'getContext' 回答1: The code I ended up using to support IE8 was the following. <!--[if !IE 8]><!--><script src="https://www.google.com/recaptcha/api.js"></script><!--<![endif]--> <!--[if IE 8]><script src="https://www.google.com/recaptcha/api

问题 Ok, here is an issue: in the project i'm working on, we can't rely on server-side sessions for any functionality. The problem is that common captcha solutions from preventing robotic submits require session to store the string to match captcha against. The question is - is there any way to solve the problem without using sessions? What comes to my mind - is serving hidden form field, containing some hash, along with captcha input field, so that server then can match these two values together.