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<?php
function ascii_art_captcha_help($section) {
switch ($section) {
case 'admin/user/captcha/ascii_art_captcha':
$output = '<p>' . t('The ASCII art CAPTCHA shows a random character code in ASCII art style. Example with current settings:') . '</p>';
$captcha = ascii_art_captcha_captcha('generate', 'ASCII art CAPTCHA');
$output .= $captcha['form']['ascii']['#value'];
return $output;
}
}
function ascii_art_captcha_menu($may_cache) {
$items = array();
if ($may_cache) {
$items[] = array(
'path' => 'admin/user/captcha/ascii_art_captcha',
'title' => t('ASCII art CAPTCHA'),
'callback' => 'drupal_get_form',
'callback arguments' => array(
'ascii_art_captcha_settings_form',
),
'type' => MENU_LOCAL_TASK,
);
}
return $items;
}
function _ascii_art_captcha_available_fonts() {
$available_fonts = array();
$fontsdirectory = drupal_get_path('module', 'ascii_art_captcha') . '/fonts';
$pattern = 'ascii_art_captcha_font_([a-zA-Z0-9]+)\\.[iI][nN][cC]$';
foreach (file_scan_directory($fontsdirectory, $pattern) as $filename => $font) {
$regs = array();
ereg($pattern, $font->basename, $regs);
$available_fonts[$regs[1]] = $regs[1];
}
asort($available_fonts);
return $available_fonts;
}
function ascii_art_captcha_settings_form() {
$form = array();
$available_fonts = _ascii_art_captcha_available_fonts();
$form['ascii_art_captcha_code_length'] = array(
'#type' => 'select',
'#title' => t('Code length'),
'#options' => array(
4 => 4,
5 => 5,
6 => 6,
7 => 7,
8 => 8,
9 => 9,
10 => 10,
),
'#default_value' => (int) variable_get('ascii_art_captcha_code_length', 6),
);
$form['ascii_art_captcha_font'] = array(
'#type' => 'select',
'#title' => t('Font'),
'#options' => $available_fonts,
'#default_value' => variable_get('ascii_art_captcha_font', 'standard'),
'#description' => t('Define the ASCII art font to use. Note that some characters are not very recognizable in some (small/weird) fonts. Make sure to disable the right character sets in these cases.'),
);
$font_sizes = array(
0 => t('default'),
);
foreach (array(
4,
6,
8,
9,
10,
11,
12,
) as $pt) {
$font_sizes[$pt] = $pt . 'pt';
}
$form['ascii_art_captcha_font_size'] = array(
'#type' => 'select',
'#title' => t('Font size'),
'#options' => $font_sizes,
'#default_value' => variable_get('ascii_art_captcha_font_size', 0),
'#description' => t('Set the font size for the ASCII art.'),
);
$form['ascii_art_captcha_allowed_characters'] = array(
'#type' => 'checkboxes',
'#title' => 'Character sets to use',
'#options' => array(
'upper' => t('upper case characters'),
'lower' => t('lower case characters'),
'digit' => t('digits'),
),
'#default_value' => variable_get('ascii_art_captcha_allowed_characters', array(
'upper' => 'upper',
'lower' => 'lower',
'digit' => 'digit',
)),
'#description' => t('Enable the character sets to use in the code. Choose wisely by taking the recognizability of the used font into account.'),
);
return system_settings_form($form);
}
function ascii_art_captcha_settings_form_validate($form_id, $form_values) {
if ($form_id = 'ascii_art_captcha_settings_form') {
if ($form_values['ascii_art_captcha_allowed_characters'][0]) {
form_set_error('ascii_art_captcha_allowed_characters', t('You should select at least one type of characters to use.'));
}
}
}
function _ascii_art_captcha_get_allowed_characters() {
$allowed_chars = array();
$allowed_chars_settings = variable_get('ascii_art_captcha_allowed_characters', array(
'upper' => 'upper',
'lower' => 'lower',
'digit' => 'digit',
));
if ($allowed_chars_settings['upper']) {
$allowed_chars = array_merge($allowed_chars, array(
'A',
'B',
'C',
'D',
'E',
'F',
'G',
'H',
'I',
'J',
'K',
'L',
'M',
'N',
'P',
'Q',
'R',
'S',
'T',
'U',
'V',
'W',
'X',
'Y',
'Z',
));
}
if ($allowed_chars_settings['lower']) {
$allowed_chars = array_merge($allowed_chars, array(
'a',
'b',
'c',
'd',
'e',
'f',
'g',
'h',
'i',
'j',
'k',
'l',
'm',
'n',
'p',
'q',
'r',
's',
't',
'u',
'v',
'w',
'x',
'y',
'z',
));
}
if ($allowed_chars_settings['digit']) {
$allowed_chars += array_merge($allowed_chars, array(
'1',
'2',
'3',
'4',
'5',
'6',
'7',
'8',
'9',
));
}
return $allowed_chars;
}
function ascii_art_captcha_captcha($op, $captcha_type = '', $response = '') {
switch ($op) {
case 'list':
return array(
'ASCII art CAPTCHA',
);
case 'generate':
if ($captcha_type == "ASCII art CAPTCHA") {
$allowed_chars = _ascii_art_captcha_get_allowed_characters();
$code_length = (int) variable_get('ascii_art_captcha_code_length', 6);
$font_name = variable_get('ascii_art_captcha_font', 'standard');
if (!(include_once 'fonts/ascii_art_captcha_font_' . $font_name . '.inc')) {
return;
}
$font = call_user_func('ascii_art_captcha_font_' . $font_name);
if (!$font) {
return;
}
$solution = '';
$ascii_lines = array();
for ($i = 0; $i < $font['height']; $i++) {
$ascii_lines[$i] = '';
}
for ($i = 0; $i < $code_length; $i++) {
$character = $allowed_chars[array_rand($allowed_chars)];
$solution .= $character;
foreach ($font[$character] as $l => $cline) {
$ascii_lines[$l] .= ' ' . check_plain($cline);
}
}
$captcha = array();
$captcha['solution'] = $solution;
$style = 'line-height:1.1;';
if (variable_get('ascii_art_captcha_font_size', 0)) {
$style .= 'font-size:' . variable_get('ascii_art_captcha_font_size', 0) . 'pt;';
}
$captcha['form']['ascii'] = array(
'#type' => 'markup',
'#value' => '<pre class="ascii_art_captcha" style="' . $style . '">' . implode('<br />', $ascii_lines) . '</pre>',
);
$captcha['form']['captcha_response'] = array(
'#type' => 'textfield',
'#title' => t('Enter the code above'),
'#size' => 10,
'#maxlength' => 10,
'#required' => TRUE,
'#description' => t('Enter the code depicted in ASCII art style.'),
);
$captcha['preprocess'] = FALSE;
return $captcha;
}
break;
}
}
