mirror of https://github.com/hnhx/captcha.git
57 lines
1.7 KiB
PHP
57 lines
1.7 KiB
PHP
<?php
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function random_string()
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{
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//$chars = array_merge(range("A", "Z"), range("a", "z"), range(0, 9));
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$chars = array_merge(range("A", "Z"), range(0, 9));
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$random_str = "";
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for($i=0; random_int(4,8)>$i; $i++)
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$random_str .= $chars[random_int(0, count($chars)-1)];
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return $random_str;
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}
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function hex_to_rgb($hex)
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{
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list($r, $g, $b) = sscanf($hex, "#%02x%02x%02x");
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return array($r, $g, $b);
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}
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function create_captcha($captcha_string,$width,$height,$bg,$fg)
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{
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$im = imagecreate($width, $height);
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$bg_rgb = hex_to_rgb($bg);
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$fg_rgb = hex_to_rgb($fg);
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$background_color = imagecolorallocate($im, $bg_rgb[0], $bg_rgb[1], $bg_rgb[2]);
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$text_color = imagecolorallocate($im, $fg_rgb[0], $fg_rgb[1], $fg_rgb[2]);
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$text_x = 0;
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for($i=0; strlen($captcha_string)>$i; $i++)
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{
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$text_y = random_int(0, $height- ($height*0.60));
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imagestring($im, 5, $text_x, $text_y, $captcha_string[$i], $text_color);
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$text_x += 10 + random_int(0, $width / 10 - 5);
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}
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for($i=0; random_int(8, 15)>$i; $i++)
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imageline($im, random_int(0,$width), random_int(0,$height), random_int(0,$width), random_int(0,$width), $text_color);
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imagepng($im);
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imagedestroy($im);
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}
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header("Content-Type: image/png");
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$captcha_string = random_string();
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$width = 130;
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$height = 30;
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$bg = "#000000";
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$fg = "#ffffff";
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create_captcha($captcha_string,$width,$height,$bg,$fg);
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session_start();
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$_SESSION["captcha"] = $captcha_string;
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?>
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