用php做出類似Google的字詞驗證圖片

[yehlu]

http://samsharehome.blogspot.com/2008/12/phpgoogle.html

雖然日前Google字詞驗證與CAPTCHA都已經宣告被破解, 但還是用php來寫出一個類似的介面, php圖片要扭曲必須要用像素位移的方式, 所以出來的圖片會有一點沙沙的感覺。 其實也可以使用其他附加軟體進行扭曲的動作, 但那樣可攜性就相對降低了。
使用時請在這支php同資料夾加上font資料夾, 裡面放置要產生驗證碼的字型, 幾個都可以, 會隨機挑選, 驗證碼存在$_SESSION['vCode']中, 格式為 驗證碼|時間, 比對時要explode("|", $_SESSION['vCode'])。

也可以加上干擾線條與點數, 變的更難辨識。


<php> SetImage(2,7,130,60,120,1);

class vCodeImage
{
var $mode; // 1.文字模式, 2.字母模式, 3.文字字母混合模式, 4.其他文字字母優化模式
var $v_num; // 驗證碼個數
var $img_w; // 圖像寬度
var $img_h; // 圖像�度
var $int_pixel_num; // 干擾像數個數
var $int_line_num; // 干擾線條數量
var $font_dir; // 字型文件路徑
var $border; // 圖像邊框
var $borderColor; // 圖像邊框顏色

function SetImage($mode, $v_num, $img_w, $img_h, $int_pixel_num, $int_line_num, $font_dir='font', $border=false, $borderColor='0,0,0')
{
if(!isset($_SESSION['vCode'])){
session_register('vCode');
}
$_SESSION['vCode'] = "";

$this -> mode = $mode;
$this -> v_num = $v_num;
$this -> img_w = $img_w;
$this -> img_h = $img_h;
$this -> int_pixel_num = $int_pixel_num;
$this -> int_line_num = $int_line_num;
$this -> font_dir = $font_dir;
$this -> border = $border;
$this -> borderColor = $borderColor;
$this -> GenerateImage();
}

function GetChar($mode)
{
if($mode == "1"){
$ychar = "0,1,2,3,4,5,6,7,8,9";
}else if($mode == "2"){
$ychar = "a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z";
}else if($mode == "3"){
$ychar = "0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z";
}else{
$ychar = "3,4,5,6,7,8,9,a,b,c,d,h,k,p,r,s,t,w,x,y";
}
return $ychar;
}

function RandColor($rs, $re, $gs, $ge, $bs, $be)
{
$r = mt_rand($rs, $re);
$g = mt_rand($gs, $ge);
$b = mt_rand($bs, $be);
return array($r, $g, $b);
}

function GenerateImage()
{
$fonts = scandir($this -> font_dir);
$ychar = $this -> GetChar($this -> mode);
$list = explode(",", $ychar);
$cmax = count($list) - 1;
$fmax = count($fonts) - 2;
$fontrand = mt_rand(2, $fmax);
$font = $this -> font_dir."/".$fonts[$fontrand];

// 驗證碼
$v_code = "";
for($i = 0; $i <this> v_num; $i++){
$randnum = mt_rand(0, $cmax);
$this_char = $list[$randnum];
$v_code .= $this_char;
}

// 扭曲圖形
$im = imagecreatetruecolor ($this -> img_w + 50, $this -> img_h);
$color = imagecolorallocate($im, 32, 81, 183);
$ranum = mt_rand(0, 2);
if($ranum == 0){
$color = imagecolorallocate($im, 32, 81, 183);
}else if($ranum == 1){
$color = imagecolorallocate($im, 17, 158, 20);
}else{
$color = imagecolorallocate($im, 196, 31, 11);
}
imagefill($im, 0, 0, imagecolorallocate($im, 255, 255, 255) );
imagettftext ($im, 24, mt_rand(-6, 6), 10, $this -> img_h * 0.6, $color, $font, $v_code);

// 干擾線條
for($i = 0; $i <this> int_line_num; $i++){
$rand_color_line = $color;
imageline($im, mt_rand(2,intval($this -> img_w/3)), mt_rand(10,$this -> img_h - 10), mt_rand(intval($this -> img_w - ($this -> img_w/3) + 50),$this -> img_w), mt_rand(0,$this -> img_h), $rand_color_line);
}

$ranum = mt_rand(0, 1);
$dis_range = mt_rand(8, 12);
$distortion_im = imagecreatetruecolor ($this -> img_w * 1.5 ,$this -> img_h);
imagefill($distortion_im, 0, 0, imagecolorallocate($distortion_im, 255, 255, 255));
for ($i = 0; $i <this> img_w + 50; $i++) {
for ($j = 0; $j <this> img_h; $j++) {
$rgb = imagecolorat($im, $i, $j);
if($ranum == 0){
if( (int)($i+40+cos($j/$this -> img_h * 2 * M_PI) * 10) <imagesx> img_h * 2 * M_PI) * 10) >=0 ) {
imagesetpixel ($distortion_im, (int)($i+10+cos($j/$this -> img_h * 2 * M_PI - M_PI * 0.4) * $dis_range), $j, $rgb);
}
}else{
if( (int)($i+40+sin($j/$this -> img_h * 2 * M_PI) * 10) <imagesx> img_h * 2 * M_PI) * 10) >=0 ) {
imagesetpixel ($distortion_im, (int)($i+10+sin($j/$this -> img_h * 2 * M_PI - M_PI * 0.4) * $dis_range), $j, $rgb);
}
}
}
}

// 干擾像素
for($i = 0; $i <this> int_pixel_num; $i++){
$rand_color_pixel = $color;
imagesetpixel($distortion_im, mt_rand() % $this -> img_w + 20, mt_rand() % $this -> img_h, $rand_color_pixel);
}

// 繪製邊框
if($this -> border){
$border_color_line = $color;
imageline($distortion_im, 0, 0, $this -> img_w, 0, $border_color_line); // 上橫
imageline($distortion_im, 0, 0, 0, $this -> img_h, $border_color_line); // 左豎
imageline($distortion_im, 0, $this -> img_h-1, $this -> img_w, $this -> img_h-1, $border_color_line); // 下橫
imageline($distortion_im, $this -> img_w-1, 0, $this -> img_w-1, $this -> img_h, $border_color_line); // 右豎
}

imageantialias($distortion_im, true); // 消除鋸齒

$time = time();
$_SESSION['vCode'] = $v_code."|".$time; // 把驗證碼與時間賦與給 $_SESSION[vCode], 時間欄位可以驗證��否超時

// 生成圖像給瀏覽器
if (function_exists("imagegif")) {
header ("Content-type: image/gif");
imagegif($distortion_im);
}else if (function_exists("imagepng")) {
header ("Content-type: image/png");
imagepng($distortion_im);
}else if (function_exists("imagejpeg")) {
header ("Content-type: image/jpeg");
imagejpeg($distortion_im, "", 80);
}else if (function_exists("imagewbmp")) {
header ("Content-type: image/vnd.wap.wbmp");
imagewbmp($distortion_im);
}else{
die("No Image Support On This Server !");
}

imagedestroy($im);
imagedestroy($distortion_im);
}
}
?>