jamesjmann Posted February 25, 2011 Share Posted February 25, 2011 I want to build a captcha from scratch, as I'm all about doing things myself, and I've proposed a nice idea on how I can achieve that, but I'm sort of lost... What I want to do is write a script that will generate a random string of both letters and numbers, with the ability to set a limit on how many characters are generated. Then, I want to store that string within a variable called "random_string". Once the user types in that code, their input would get captured in a separate php file and stored within a variable like so: $captcha_code = $_POST['catpcha_code']; Then, I would write a code to see if the user's input matches the random character string from the html: <?php if ($random_string == $captcha_code) { mail($to, $subject, $body); } else { echo ("The code you entered did not match the captcha. Please go back and try again."); } ?> Is this possible? I haven't yet tried it myself, because I don't know how to generate random strings of characters, but I was just wondering if perhaps I'm on the right track? Any suggestions or advice is appreciated =) Quote Link to comment Share on other sites More sharing options...
jamesjmann Posted February 25, 2011 Author Share Posted February 25, 2011 Ok this is what I have so far: <?php if (isset($_POST['submit'])) { $to = "myemailaddress"; $name = $_REQUEST['name'] ; $email = $_REQUEST['email'] ; $message = $_REQUEST['message'] ; $subject = $_REQUEST['subject'] ; $header = "Contact Form"; $captcha = $_REQUEST['captcha']; $browser = $_SERVER['HTTP_USER_AGENT']; $ip = $_SERVER['REMOTE_ADDR']; $reason = $_REQUEST['reason']; $admin = "MyName"; for($i=0; $i<10; $i++){ $random_string .= chr(rand(0,25)+65); } if ($captcha != $random_string) { echo("The code you entered for the captcha was incorrect. Please go back and try again."); } else { mail($to, $header, "DJSmiley.Net Feedback\n\nVisitor Information:\n$name\n$email\n$ip\n$browser\n\nMessage - $subject\n$name says:\n$message"); mail($email, $admin, "Thank you for your feedback! I will try to get back to you with a reply when I can! \n\nTil' then \n-DJ Smiley"); echo( "Thank you for your feedback!" ); } } else { ?> <h2><a name="Feedback" id="Feedback"></a>Feedback</h2> <form name="contact" method="post" action="<?php $_SERVER['PHP_SELF']?>"> <table width="100%" border="0"> <tr> <td width="27%">Name:</td> <td width="73%"><label> </label> <label> <input name="name2" type="text" class="commentBoxforms" id="name2" /> </label></td> </tr> <tr> <td>Email: </td> <td> <input name="email2" type="text" class="commentBoxforms" id="email2" /> </td> </tr> <tr> <td>Subject:</td> <td><input name="subject" type="text" class="commentBoxforms" id="subject" /></td> </tr> <tr> <td>Message:</td> <td><label> <textarea name="message" cols="45" rows="5" class="commentField1" id="message"></textarea> <br /> </label></td> </tr> <tr> <td>Reason For Contacting:</td> <td><table width="50%" border="0"> <tr> <td><input name="reason" type="radio" id="endearment" value="endearment" checked="checked" /></td> <td><label for="endearment">Endearment</label></td> <td><input type="radio" name="reason" id="question" value="question"/></td> <td width="43%"><label for="question">Question</label></td> </tr> <tr> <td width="11%"><input type="radio" name="reason" id="general" value="general" /></td> <td width="37%"><label for="general">General</label></td> <td width="9%"><input type="radio" name="reason" id="suggestion" value="suggestion"/></td> <td><label for="suggestion">Suggestion</label></td> </tr> <tr> <td><input type="radio" name="reason" id="professional" value="professional" /></td> <td><label for="professional">Professional</label></td> <td><input type="radio" name="reason" id="technical" value="technical"/></td> <td><label for="technical">Technical</label></td> </tr> </table></td> </tr> <tr> <td><p>Captcha:</p> <p>Are you human?<br /> Enter the following:</p> <p><?php echo "<p class=\"captcha\">" .$random_string. "</p>"; ?></p> <p>*case sensitive</p></td> <td><input name="captcha" type="text" class="commentBoxforms" id="captcha" /></td> </tr> <tr> <td> </td> <td><input type="submit" class="Button1" value="Send Message" id="submit" name="submit"/> <input type="reset" class="Button1" value="Reset Form" /></td> </tr> </table> <a href="places_you_can_find_me.php"></a> </form> <?php } ?> The problem I have here is that I can't get $random_string to = the user input. Help please? Quote Link to comment Share on other sites More sharing options...
cunoodle2 Posted February 25, 2011 Share Posted February 25, 2011 Yup. Looks good to me. I would just create a function to create a random string and then go from there. Here is an article on how to create that exact function.. http://snippets.dzone.com/posts/show/3123 Quote Link to comment Share on other sites More sharing options...
jamesjmann Posted February 25, 2011 Author Share Posted February 25, 2011 Yup. Looks good to me. I would just create a function to create a random string and then go from there. Here is an article on how to create that exact function.. http://snippets.dzone.com/posts/show/3123 I have it working so that it generates a random string, but I can't get that string to echo in the html so the user knows what to type. Quote Link to comment Share on other sites More sharing options...
carbayon Posted February 25, 2011 Share Posted February 25, 2011 I know you want to do it yourself, but I have a simple captcha that does as you said. File 1 contains the list of characters to use and those to avoid.... <?php //returns a string of random text function random_text($count, $rm_similar = true){ //create list of characters $chars = array_flip(array_merge(range(0,9), range('A','Z'), range('a','z'))); //remove similar charactes that might lead to confussion if ($rm_similar){ unset($chars[0], $chars[1], //Ad characters that could be confused 1/l; 2/Z; O/0; 8/B..... $chars['Z']); } //end if //generate the string of random text for ($i = 0, $text = ''; $i < $count; $i++){ $text .= array_rand($chars); } //end for return $text; } //end function ?> Then you have another script that creates an image; <?php //This point to the file above include 'exceptions.php'; // must start or continue session and save CAPTCHA string in $_SESSION for it // to be available to other requests if (!isset($_SESSION)) { session_start(); header('Cache-control: private'); } // create an image $width = 155; $height = 20; $image = imagecreate(170, 20); // fill the image background color $bg_color = imagecolorallocate($image, 0x33, 0x66, 0xFF); imagefilledrectangle($image, 0, 0, $width, $height, $bg_color); // fetch random text $text = random_text(5); //5 is the number of characters, increase-decrease as needed // determine x and y coordinates for centering text $font = 8; $x = imagesx($image) / 2 - strlen($textp) * imagefontwidth($font) / 2; $y = imagesy($image) / 2 - imagefontheight($font) / 2; // write text on image $fg_color = imagecolorallocate($image, 0xFF, 0xFF, 0xFF); imagestring($image, $font, $x, $y, $text, $fg_color); // save the CAPTCHA string for later comparison $_SESSION['captcha'] = $text1 // output the image header('Content-type: image/png'); imagepng($image); imagedestroy($image); ?> This is how you call the captcha from the HTML website; <img src="../images/captcha.php?nocache=<?php echo time(); ?>" alt=""/> <input type="text" name="captcha" size="1/> An finally how you can process the information sent from the form; if(empty($_POST["captcha"])){ echo "Please enter a CAPTCHA security code.<br />"; }//if(empty($_POST["captcha"])) elseif($_SESSION["captcha"] !== $captcha){ $msg_reg .= "Please enter the correct CAPTCHA security code.<br />"; }//elseif($_SESSION["captcha"] !== $captcha) I hope this helps you on your journey... you can see mine (with modifications) working on http://merso.eu click on registration link. Regards Quote Link to comment Share on other sites More sharing options...
jamesjmann Posted February 25, 2011 Author Share Posted February 25, 2011 I know you want to do it yourself, but I have a simple captcha that does as you said. File 1 contains the list of characters to use and those to avoid.... <?php //returns a string of random text function random_text($count, $rm_similar = true){ //create list of characters $chars = array_flip(array_merge(range(0,9), range('A','Z'), range('a','z'))); //remove similar charactes that might lead to confussion if ($rm_similar){ unset($chars[0], $chars[1], //Ad characters that could be confused 1/l; 2/Z; O/0; 8/B..... $chars['Z']); } //end if //generate the string of random text for ($i = 0, $text = ''; $i < $count; $i++){ $text .= array_rand($chars); } //end for return $text; } //end function ?> Then you have another script that creates an image; <?php //This point to the file above include 'exceptions.php'; // must start or continue session and save CAPTCHA string in $_SESSION for it // to be available to other requests if (!isset($_SESSION)) { session_start(); header('Cache-control: private'); } // create an image $width = 155; $height = 20; $image = imagecreate(170, 20); // fill the image background color $bg_color = imagecolorallocate($image, 0x33, 0x66, 0xFF); imagefilledrectangle($image, 0, 0, $width, $height, $bg_color); // fetch random text $text = random_text(5); //5 is the number of characters, increase-decrease as needed // determine x and y coordinates for centering text $font = 8; $x = imagesx($image) / 2 - strlen($textp) * imagefontwidth($font) / 2; $y = imagesy($image) / 2 - imagefontheight($font) / 2; // write text on image $fg_color = imagecolorallocate($image, 0xFF, 0xFF, 0xFF); imagestring($image, $font, $x, $y, $text, $fg_color); // save the CAPTCHA string for later comparison $_SESSION['captcha'] = $text1 // output the image header('Content-type: image/png'); imagepng($image); imagedestroy($image); ?> This is how you call the captcha from the HTML website; <img src="../images/captcha.php?nocache=<?php echo time(); ?>" alt=""/> <input type="text" name="captcha" size="1/> An finally how you can process the information sent from the form; if(empty($_POST["captcha"])){ echo "Please enter a CAPTCHA security code.<br />"; }//if(empty($_POST["captcha"])) elseif($_SESSION["captcha"] !== $captcha){ $msg_reg .= "Please enter the correct CAPTCHA security code.<br />"; }//elseif($_SESSION["captcha"] !== $captcha) I hope this helps you on your journey... you can see mine (with modifications) working on http://merso.eu click on registration link. Regards Finally, an image generated captcha script that doesn't require downloading a ton of mb's worth of files. I'll try it out real quick and let you know if I encounter any problems...thanks for the script! Quote Link to comment Share on other sites More sharing options...
jamesjmann Posted February 25, 2011 Author Share Posted February 25, 2011 What do I name the image generating script file as? Quote Link to comment Share on other sites More sharing options...
jamesjmann Posted February 25, 2011 Author Share Posted February 25, 2011 Couple things... I stored both captcha scripts in a directory called "captcha", called the image generating script "captcha.php", and called the captcha in my html as so: <img src="../captcha/captcha.php?nocache=<?php echo time(); ?>" alt=""/> Is this right? Because the captcha is not being displayed on my website. Quote Link to comment Share on other sites More sharing options...
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