PHP实现GIF图片验证码

2024-05-04 23:40:05

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这篇文章主要介绍了PHP如何生成GIF动态图片验证码，在注册界面时大家经常用到验证码，需要了解的朋友可以参考下

这是一个用PHP生成GIF动画来实现动态图片验证码的程序，非常实用，是php用户注册登录界面经常需要用到的验证码程序，有需要GIF动态图片验证码功能的朋友可以收藏一下。

第一步：创建ImageCode.php文件，验证码生成函数代码如下：

<?php

/**

* ImageCode 生成GIF图片验证

* @param $string 字符串

* @param $width 宽度

* @param $height 高度

* */

function ImageCode($string = '', $width = 75, $height = 25)

{

$authstr = $string ? $string : ((time() % 2 == 0) ? mt_rand(1000, 9999) : mt_rand(10000, 99999));

$board_width = $width;

$board_height = $height;

// 生成一个32帧的GIF动画

for($i = 0; $i < 32; $i++)

{

ob_start();

$image = imagecreate($board_width, $board_height);

imagecolorallocate($image, 0,0,0);

// 设定文字颜色数组

$colorList[] = ImageColorAllocate($image, 15,73,210);

$colorList[] = ImageColorAllocate($image, 0,64,0);

$colorList[] = ImageColorAllocate($image, 0,0,64);

$colorList[] = ImageColorAllocate($image, 0,128,128);

$colorList[] = ImageColorAllocate($image, 27,52,47);

$colorList[] = ImageColorAllocate($image, 51,0,102);

$colorList[] = ImageColorAllocate($image, 0,0,145);

$colorList[] = ImageColorAllocate($image, 0,0,113);

$colorList[] = ImageColorAllocate($image, 0,51,51);

$colorList[] = ImageColorAllocate($image, 158,180,35);

$colorList[] = ImageColorAllocate($image, 59,59,59);

$colorList[] = ImageColorAllocate($image, 0,0,0);

$colorList[] = ImageColorAllocate($image, 1,128,180);

$colorList[] = ImageColorAllocate($image, 0,153,51);

$colorList[] = ImageColorAllocate($image, 60,131,1);

$colorList[] = ImageColorAllocate($image, 0,0,0);

$fontcolor = ImageColorAllocate($image, 0,0,0);

$gray = ImageColorAllocate($image, 245,245,245);

$color = imagecolorallocate($image, 255,255,255);

$color2 = imagecolorallocate($image, 255,0,0);

imagefill($image, 0, 0, $gray);

$space = 15; // 字符间距

if($i > 0) // 屏蔽第一帧

{

for ($k = 0; $k < strlen($authstr); $k++)

{

$colorRandom = mt_rand(0,sizeof($colorList)-1);

$float_top = rand(0,4);

$float_left = rand(0,3);

imagestring($image, 6, $space * $k, $top + $float_top, substr($authstr, $k, 1), $colorList[$colorRandom]);

}

}

for ($k = 0; $k < 20; $k++)

{

$colorRandom = mt_rand(0,sizeof($colorList)-1);

imagesetpixel($image, rand()%70 , rand()%15 , $colorList[$colorRandom]);

}

// 添加干扰线

for($k = 0; $k < 3; $k++)

{

$colorRandom = mt_rand(0, sizeof($colorList)-1);

// $todrawline = rand(0,1);

$todrawline = 1;

if($todrawline)

{

imageline($image, mt_rand(0, $board_width), mt_rand(0,$board_height), mt_rand(0,$board_width), mt_rand(0,$board_height), $colorList[$colorRandom]);

}

else

{

$w = mt_rand(0,$board_width);

$h = mt_rand(0,$board_width);

imagearc($image, $board_width - floor($w / 2) , floor($h / 2), $w, $h, rand(90,180), rand(180,270), $colorList[$colorRandom]);

}

}

imagegif($image);

imagedestroy($image);

$imagedata[] = ob_get_contents();

ob_clean();

++$i;

}

$gif = new GIFEncoder($imagedata);

Header ('Content-type:image/gif');

echo $gif->GetAnimation();

}

/**

* GIFEncoder类

* */

Class GIFEncoder

{

var $GIF = "GIF89a"; /* GIF header 6 bytes */

var $VER = "GIFEncoder V2.06"; /* Encoder version */

var $BUF = Array ( );

var $LOP = 0;

var $DIS = 2;

var $COL = -1;

var $IMG = -1;

var $ERR = Array (

'ERR00' =>"Does not supported function for only one image!",

'ERR01' =>"Source is not a GIF image!",

'ERR02' =>"Unintelligible flag ",

'ERR03' =>"Could not make animation from animated GIF source",

);

function GIFEncoder ($GIF_src, $GIF_dly = 100, $GIF_lop = 0, $GIF_dis = 0, $GIF_red = 0, $GIF_grn = 0, $GIF_blu = 0, $GIF_mod = 'bin' )

{

if (!is_array($GIF_src) && !is_array($GIF_tim))

{

printf ( "%s: %s", $this->VER, $this->ERR['ERR00']);

exit( 0 );

}

$this->LOP = ($GIF_lop > -1) ? $GIF_lop : 0;

$this->DIS = ($GIF_dis > -1) ? (( $GIF_dis < 3 ) ? $GIF_dis : 3) : 2;

$this->COL = ($GIF_red > -1 && $GIF_grn > -1 && $GIF_blu > -1) ? ($GIF_red | ($GIF_grn << 8) | ($GIF_blu << 16)) : -1;

for ($i = 0, $src_count = count($GIF_src); $i < $src_count; $i++ )

{

if (strToLower( $GIF_mod ) == "url")

{

$this->BUF[] = fread (fopen($GIF_src [$i], "rb"), filesize ($GIF_src [$i]));

}

elseif(strToLower($GIF_mod) == "bin")

{

$this->BUF [ ] = $GIF_src [ $i ];

}

else

{

printf("%s: %s ( %s )!", $this->VER, $this->ERR [ 'ERR02' ], $GIF_mod);

exit(0);

}

if (substr($this->BUF[$i], 0, 6) != "GIF87a" && substr($this->BUF [$i], 0, 6) != "GIF89a")

{

printf( "%s: %d %s", $this->VER, $i, $this->ERR ['ERR01']);

exit(0);

}

for ($j = (13 + 3 * (2 << (ord($this->BUF[$i]{10}) & 0x07 ))), $k = TRUE; $k; $j++)

{

switch ($this->BUF [$i]{$j})

{

case "!":

if ((substr($this->BUF[$i], ($j + 3), 8)) == "NETSCAPE")

{

printf( "%s: %s ( %s source )!", $this->VER, $this->ERR ['ERR03'], ($i + 1));

exit( 0 );

}

break;

case ";":

$k = FALSE;

break;

}

}

}

GIFEncoder::GIFAddHeader();

for($i = 0, $count_buf = count($this->BUF); $i < $count_buf; $i++)

{

GIFEncoder::GIFAddFrames($i, $GIF_dly[$i]);

}

GIFEncoder::GIFAddFooter();

}

function GIFAddHeader ( )

{

$cmap = 0;

if (ord($this->BUF[0]{10}) & 0x80 )

{

$cmap = 3 * ( 2 << ( ord ( $this->BUF [ 0 ]{10} ) & 0x07 ));

$this->GIF .= substr ( $this->BUF [ 0 ], 6, 7);

$this->GIF .= substr ( $this->BUF [ 0 ], 13, $cmap);

$this->GIF .= "!/377/13NETSCAPE2.0/3/1" . GIFEncoder::GIFWord ( $this->LOP ) . "/0";

}

}

function GIFAddFrames ( $i, $d )

{

$Locals_str = 13 + 3 * (2 <<(ord($this->BUF[$i]{10}) & 0x07));

$Locals_end = strlen($this->BUF[$i]) - $Locals_str - 1;

$Locals_tmp = substr ($this->BUF[$i], $Locals_str, $Locals_end);

$Global_len = 2 << (ord( $this->BUF [0]{10} ) & 0x07 );

$Locals_len = 2 << (ord( $this->BUF[$i]{10}) & 0x07);

$Global_rgb = substr($this->BUF[0], 13, 3 * (2 << ( ord ( $this->BUF[0]{10} ) & 0x07)));

$Locals_rgb = substr ( $this->BUF[$i], 13, 3 * (2 << ( ord ( $this->BUF[$i]{10} ) & 0x07)));

$Locals_ext = "!/xF9/x04" . chr(($this->DIS << 2) + 0) . chr(($d >> 0) & 0xFF) . chr(($d >> 8) & 0xFF) . "/x0/x0";

if ( $this->COL > -1 && ord($this->BUF[$i]{10}) & 0x80)

{

for($j = 0; $j < (2 << (ord( $this->BUF[$i]{10}) & 0x07)); $j++ )

{

if(ord ($Locals_rgb{3 * $j + 0}) == ($this->COL >> 0) & 0xFF && ord ( $Locals_rgb { 3 * $j + 1 } ) == ( $this->COL >> 8 ) & 0xFF && ord ( $Locals_rgb { 3 * $j + 2 } ) == ( $this->COL >> 16 ) & 0xFF )

{

$Locals_ext = "!/xF9/x04" . chr(($this->DIS << 2) + 1) . chr (( $d >> 0) & 0xFF) . chr (( $d >> 8) & 0xFF) . chr ($j) . "/x0";

break;

}

}

}

switch ( $Locals_tmp { 0 } )

{

case "!":

$Locals_img = substr($Locals_tmp, 8, 10);

$Locals_tmp = substr($Locals_tmp, 18, strlen ($Locals_tmp) - 18);

break;

case ",":

$Locals_img = substr($Locals_tmp, 0, 10);

$Locals_tmp = substr($Locals_tmp, 10, strlen($Locals_tmp) - 10);

break;

}

if ( ord ( $this->BUF[$i]{10} ) & 0x80 && $this->IMG > -1 )

{

if ( $Global_len == $Locals_len )

{

if ( GIFEncoder::GIFBlockCompare ( $Global_rgb, $Locals_rgb, $Global_len ) )

{

$this->GIF .= ( $Locals_ext . $Locals_img . $Locals_tmp );

}

else

{

$byte = ord ( $Locals_img{9});

$byte |= 0x80;

$byte &= 0xF8;

$byte |= ( ord ( $this->BUF [ 0 ]{10}) & 0x07);

$Locals_img{9} = chr($byte);

$this->GIF .= ($Locals_ext . $Locals_img . $Locals_rgb . $Locals_tmp);

}

}

else

{

$byte = ord($Locals_img{9});

$byte |= 0x80;

$byte &= 0xF8;

$byte |= (ord($this->BUF[$i]{10}) & 0x07);

$Locals_img {9} = chr($byte);

$this->GIF .= ($Locals_ext . $Locals_img . $Locals_rgb . $Locals_tmp);

}

}

else

{

$this->GIF .= ( $Locals_ext . $Locals_img . $Locals_tmp );

}

$this->IMG = 1;

}

function GIFAddFooter ( ) {

$this->GIF .= ";";

}

function GIFBlockCompare ( $GlobalBlock, $LocalBlock, $Len )

{

for ( $i = 0; $i < $Len; $i++ )

{

if($GlobalBlock { 3 * $i + 0 } != $LocalBlock { 3 * $i + 0 } || $GlobalBlock { 3 * $i + 1 } != $LocalBlock { 3 * $i + 1 } || $GlobalBlock { 3 * $i + 2 } != $LocalBlock{3 * $i + 2})

{

return ( 0 );

}

}

return ( 1 );

}

function GIFWord ( $int )

{

return ( chr ( $int & 0xFF ) . chr ( ( $int >> 8 ) & 0xFF ) );

}

function GetAnimation ( )

{

return ($this->GIF);

}

}

第二步：验证码生成，创建yzimg.php，并引用入文件ImageCode.php。代码如下：

<?php

if(!isset($_SESSION)){

session_start();

}

require_once(dirname(__FILE__)."ImageCode.php");

unset($_SESSION['yzm']);

$randCode = '';

$chars = 'abcdefghjkmnpqrstuvwxyzABCDEFGHJKLMNPRSTUVWXYZ23456789';

for ( $i = 0; $i < 4; $i++ )

{

$randCode .= substr($chars, mt_rand(0, strlen($chars) - 1), 1);

}

$_SESSION['yzm']=$randCode; // 记录session

ImageCode($randCode, 60);

/*方法二*/

/*$authstr = mt_rand(1000, 9999); // 生成随机字符串

$_SESSION['yzm'] = $authstr; // 记录session

ImageCode($authstr, 60); // 显示GIF动画*/

?>

第三步：调用和显示验证码，在需要添加验证码的页面加入以下代码，代码如下：

<input name="yzm" type="text" class="input1" size="12" style="width:70px;"/>

<SCRIPT LANGUAGE="JavaScript">



</SCRIPT>