PHP绘图函数生成图片验证码

梦里梦外; 2022-08-20 09:24 203阅读 0赞

**PHP绘图函数生成图片验证码**

<?php
      session_start();
    
      // Set some important CAPTCHA constants
      define('CAPTCHA_NUMCHARS', 6);  // number of characters in pass-phrase
      define('CAPTCHA_WIDTH', 100);   // width of image
      define('CAPTCHA_HEIGHT', 25);   // height of image
    
      // Generate the random pass-phrase
      $pass_phrase = "";
      for ($i = 0; $i < CAPTCHA_NUMCHARS; $i++) {
        $pass_phrase .= chr(rand(97, 122));
      }
    
      // Store the encrypted pass-phrase in a session variable
      $_SESSION['pass_phrase'] = SHA($pass_phrase);
    
      // Create the image
      $img = imagecreatetruecolor(CAPTCHA_WIDTH, CAPTCHA_HEIGHT);
    
      // Set a white background with black text and gray graphics
      $bg_color = imagecolorallocate($img, 255, 255, 255);     // white
      $text_color = imagecolorallocate($img, 0, 0, 0);         // black
      $graphic_color = imagecolorallocate($img, 64, 64, 64);   // dark gray
    
      // Fill the background
      imagefilledrectangle($img, 0, 0, CAPTCHA_WIDTH, CAPTCHA_HEIGHT, $bg_color);
      // Draw some random lines
      for ($i = 0; $i < 5; $i++) {
        imageline($img, 0, rand() % CAPTCHA_HEIGHT, CAPTCHA_WIDTH, rand() % CAPTCHA_HEIGHT, $graphic_color);
      }
    
      // Sprinkle in some random dots
      for ($i = 0; $i < 50; $i++) {
        imagesetpixel($img, rand() % CAPTCHA_WIDTH, rand() % CAPTCHA_HEIGHT, $graphic_color);
      }
      // Draw the pass-phrase string
      imagettftext($img, 18, 0, 5, CAPTCHA_HEIGHT - 5, $text_color, 'Courier New Bold.ttf', $pass_phrase);
    
      // Output the image as a PNG using a header
      header("Content-type: image/png");
      imagepng($img);
    
      // Clean up
      imagedestroy($img);
    ?>

**在页面中使用这个生成验证码的脚本**

<?php
      session_start();
    ?>
    
    <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
      "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
    <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
    <head>
      <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
      <title>Guitar Wars - Add Your High Score</title>
      <link rel="stylesheet" type="text/css" href="style.css" />
    </head>
    <body>
      <h2>Guitar Wars - Add Your High Score</h2>
    
    <?php
      require_once('appvars.php');
      require_once('connectvars.php');
    
      if (isset($_POST['submit'])) {
        // Connect to the database
        $dbc = mysqli_connect(DB_HOST, DB_USER, DB_PASSWORD, DB_NAME);
    
        // Grab the score data from the POST
        $name = mysqli_real_escape_string($dbc, trim($_POST['name']));
        $score = mysqli_real_escape_string($dbc, trim($_POST['score']));
        $screenshot = mysqli_real_escape_string($dbc, trim($_FILES['screenshot']['name']));
        $screenshot_type = $_FILES['screenshot']['type'];
        $screenshot_size = $_FILES['screenshot']['size']; 
    
        // Check the CAPTCHA pass-phrase for verification
        $user_pass_phrase = SHA($_POST['verify']);
        if ($_SESSION['pass_phrase'] == $user_pass_phrase) {
          if (!empty($name) && is_numeric($score) && !empty($screenshot)) {
            if ((($screenshot_type == 'image/gif') || ($screenshot_type == 'image/jpeg') || ($screenshot_type == 'image/pjpeg') || ($screenshot_type == 'image/png'))
              && ($screenshot_size > 0) && ($screenshot_size <= GW_MAXFILESIZE)) {
              if ($_FILES['screenshot']['error'] == 0) {
                // Move the file to the target upload folder
                $target = GW_UPLOADPATH . $screenshot;
                if (move_uploaded_file($_FILES['screenshot']['tmp_name'], $target)) {
                  // Write the data to the database
                  $query = "INSERT INTO guitarwars (date, name, score, screenshot) VALUES (NOW(), '$name', '$score', '$screenshot')";
                  mysqli_query($dbc, $query);
    
                  // Confirm success with the user
                  echo '<p>Thanks for adding your new high score! It will be reviewed and added to the high score list as soon as possible.</p>';
                  echo '<p><strong>Name:</strong> ' . $name . '<br />';
                  echo '<strong>Score:</strong> ' . $score . '<br />';
                  echo '<img src="' . GW_UPLOADPATH . $screenshot . '" alt="Score image" /></p>';
                  echo '<p><a href="index.php"><< Back to high scores</a></p>';
    
                  // Clear the score data to clear the form
                  $name = "";
                  $score = "";
                  $screenshot = "";
    
                  mysqli_close($dbc);
                }
                else {
                  echo '<p class="error">Sorry, there was a problem uploading your screen shot image.</p>';
                }
              }
            }
            else {
              echo '<p class="error">The screen shot must be a GIF, JPEG, or PNG image file no greater than ' . (GW_MAXFILESIZE / 1024) . ' KB in size.</p>';
            }
    
            // Try to delete the temporary screen shot image file
            @unlink($_FILES['screenshot']['tmp_name']);
          }
          else {
            echo '<p class="error">Please enter all of the information to add your high score.</p>';
          }
        }
        else {
          echo '<p class="error">Please enter the verification pass-phrase exactly as shown.</p>';
        }
      }
    ?>
    
      <hr />
      <form enctype="multipart/form-data" method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>">
        <input type="hidden" name="MAX_FILE_SIZE" value="<?php echo GW_MAXFILESIZE; ?>" />
        <label for="name">Name:</label>
        <input type="text" id="name" name="name" value="<?php if (!empty($name)) echo $name; ?>" /><br />
        <label for="score">Score:</label>
        <input type="text" id="score" name="score" value="<?php if (!empty($score)) echo $score; ?>" /><br />
        <label for="screenshot">Screen shot:</label>
        <input type="file" id="screenshot" name="screenshot" /><br />
        <label for="verify">Verification:</label>
        <input type="text" id="verify" name="verify" value="Enter the pass-phrase." /> <img src="captcha.php" alt="Verification pass-phrase" />
        <hr />
        <input type="submit" value="Add" name="submit" />
      </form>
    </body> 
    </html>

PHP绘图函数生成图片验证码

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