Author Topic: CAPTCHA (verification code) related  (Read 28457 times)

0 Members and 1 Guest are viewing this topic.

Offline V@no

  • If you don't tell me what to do, I won't tell you where you should go :)
  • Administrator
  • 4images Guru
  • *****
  • Posts: 17.849
  • mmm PHP...
    • View Profile
    • 4images MODs Demo
CAPTCHA (verification code) related
« on: September 19, 2006, 02:09:25 PM »
This is a very basic FAQ about CAPTCHA. For more info please read docs/CAPTCHA.txt from 4images package.

Q: What is CAPTCHA?
A: A CAPTCHA (an acronym for "Completely Automated Public Turing test to tell Computers and Humans Apart") is a type of challenge-response test used in computing to determine whether or not the user is human. (you can find more info about it here)

Q: Where CAPTCHA being used in 4images?
A: By default the following forms can be protected by CAPTCHA:
  • Registration
  • E-Cards
  • Comments
  • Image-Upload

Q: How do I enable/disable CAPTCHA or how do I control it?
A: You can control the CAPTCHA system in your config.php by inserting the following configuration variables above closing
  • $captcha_enable = 1;
    A value of 1 enables the CAPTCHA system, 0 disables it.
    Default value is 1.

  • $captcha_enable_comments = 1;
    A value of 1 enables the CAPTCHA system for the comments
    form, 0 disables it.
    Default value is 1.

  • $captcha_enable_upload = 1;
    A value of 1 enables the CAPTCHA system for the upload
    form, 0 disables it.
    Default value is 1.

  • $captcha_enable_registration = 1;
    A value of 1 enables the CAPTCHA system for the
    registration form, 0 disables it.
    Default value is 1.

  • $captcha_enable_postcards = 1;
    A value of 1 enables the CAPTCHA system for the e-cards
    form, 0 disables it.
    Default value is 1.

  • $captcha_path = './captcha';
    Path to the folder which contains the CAPTCHA files
    (backgrounds, fonts).

  • $captcha_chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
    A list of letters which will be used for the
    randomly generated CAPTCHA strings
    Default value is "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ".

  • $captcha_length = 5;
    Number of letters of the CAPTCHA strings
    Default value is 5.

  • $captcha_wordfile = 0;
    If this option is set to 1, a word from
    "captcha/wordlist.txt" is used.
    Default value is 0.

  • $captcha_width = 200;
    Width of the CAPTCHA image in pixel.
    Default value is 200.

  • $captcha_height = 70;
    Height of the CAPTCHA image in pixel.
    Default value is 70.

  • $captcha_text_color = "#000000";
    Color (Hex) of the CAPTCHA text.
    Default value is "#000000" (black).

  • $captcha_text_size = 25;
    Size of the CAPTCHA text.
    Default value is 25.

  • $captcha_text_transparency = 60;
    Transparency of the CAPTCHA text.
    Default value is 60.

  • $captcha_filter_text = 1;
    If this option is set to 1, the CAPTCHA text will
    be filtered ("obscured").
    Default value is 1.

  • $captcha_filter_bg = 1;
    If this option is set to 1, the CAPTCHA background
    image will be filtered ("obscured").
    Default value is 1.

Q: Why I cannot see CAPTCHA image?
A: There are several possible reasons:
  • CAPTCHA is disabled. Look previous question for more info.
  • You are using an old/custom template that does not support CAPTCHA. You can find detailed template changes here
  • Your server does not support GD library. If you look in phpinfo() and can't find anything about GD, then most probably its not installed/enabled on your server. In that case contact your host's administrator. Until they enable/install GD you won't have other choice but disable CAPTCHA feature (see above)
  • Some FTP programms gernerate a log file after uploading files to a server. Make sure that in the directory /captacha/backgrounds/ on your server are ONLY the background images for the CAPTCHA and not any other files like wsftp.log, thumbs.db, etc.
  • You are logged in as admin. Administrators don't have to enter verifications codes

Q: How can I change the look of the captcha images?
A: [TUT] Change of the CAPTCHA-Design
or
[MOD] reCAPTCHA
« Last Edit: July 18, 2010, 08:31:44 AM by V@no »
Your first three "must do" before you ask a question:
Please do not PM me asking for help unless you've been specifically asked to do so. Such PMs will be deleted without answer. (forum rule #6)
Extension for Firefox/Thunderbird: Master Password+    Back/Forward History Tweaks (restartless)    Cookies Manager+    Fit Images (restartless for Thunderbird)

 

Post your comments here