NAME
Captcha::Stateless::Text - stateless, text-based CAPTCHAs
DESCRIPTION
A module to make stateless, text-based CAPTCHAs easy to implement. It supports:
* Simple math:
"7 + 3 = ?"
answer = 10
* Character selection:
"Provide the second, third, and sixth characters from B-G-Q-E-O-S"
answer = GQSSYNOPSIS
use Captcha::Stateless::Text;
my $captcha = Captcha::Stateless::Text->new();
# Recommend setting these to values that *you* derive
# Must be 16 bytes / 128 bits
$captcha->set_iv('gkbx5g9hsvhqrosg');
# 32 bytes / 256 bits for AES256
$captcha->set_key('tyDjb39dQ20pdva0lTpyuiowWfxSSwa9');
# Grab a question/answer data structure
my $qa = $captcha->getQA_chars();
# __or__
my $qa = $captcha->getQA_math();
# For getQA_chars(), $qa will look similar to this:
my $qa_chars = {
'q' => 'Provide the first and fifth characters from A-W-N-Z-L-X'
'a' => 'AL',
'enc_payload' => <<base-64 and url-encoded encrypted data>>,
},
# For getQA_math(), $qa will look similar to this:
my $qa_math = {
'q' => '7 + 3',
'a' => '10',
'enc_payload' => <<base-64 and url-encoded encrypted data>>,
};
# Your job now is to present the user with the question ($qa->{q}), to
# not lose the enc_payload (use a HTML <input type="hidden"> field), to
# collect the user's answer, and then validate it, like this:
my $is_valid = $captcha->validate($user_answer, $enc_payload_from_qa);
if ($is_valid) {
print "You win!\n";
} else {
print "You lose!\n";
}SUBROUTINES
The two subroutines that generate the questions and answers have a few options that can be specified to control their behavior.
my $qa = $captcha->getQA_chars($q_len, $a_len, $q_sort);
OPT DEFAULT DESCRIPTION
--------------------------------------------------------------------
$q_len 6 The character length of the question string.
$a_len 3 The number of characters in the answer.
$q_sort 1 Sort the answer characters, so that users will always
be asked for characters flowing left-to-right, or
require them to "jump around" in the question string.
my $qa = $captcha->getQA_math($a_max, $a_min);
OPT DEFAULT DESCRIPTION
--------------------------------------------------------------------
$a_max 11 The maximum value of the answer.
$a_min 2 The minimum value of the answer.COPYRIGHT
Copyright (C) 2024, Lester Hightower <hightowe@cpan.org>
LICENSE
This software is licensed under the OSI certified Artistic License, one of the licenses of Perl itself.