1 files changed, 147 insertions, 0 deletions
diff --git a/captcha.php b/captcha.php
new file mode 100755
index 0000000..21da034
--- /dev/null
+++ b/captcha.php
@@ -0,0 +1,147 @@
+<?php
+
+if(
+	!isset($_GET["k"]) ||
+	preg_match(
+		'/^c\.[0-9]+$/',
+		$_GET["k"]
+	)
+){
+	
+	header("Content-Type: text/plain");
+	echo "Fuck you";
+	die();
+}
+
+header("Content-Type: image/jpeg");
+
+$grid = apcu_fetch($_GET["k"]);
+
+if(
+	$grid === false ||
+	$grid[3] === true // has already been generated
+){
+	
+	http_response_code(304); // not modified
+	die();
+}
+
+header("Last-Modified: Thu, 01 Oct 1970 00:00:00 GMT");
+
+// only generate one captcha with this config
+apcu_store(
+	$_GET["k"],
+	[
+		$grid[0],
+		$grid[1],
+		$grid[2],
+		true // has captcha been generated?
+	],
+	120 // we give user another 2 minutes to solve
+);
+
+// generate image
+
+if(random_int(0,1) === 0){
+	
+	$theme = [
+		"bg" => "#ebdbb2",
+		"fg" => "#1d2021"
+	];
+}else{
+	
+	$theme = [
+		"bg" => "#1d2021",
+		"fg" => "#ebdbb2"
+	];
+}
+
+$im = new Imagick();
+$im->newImage(400, 400, $theme["bg"]);
+$im->setImageBackgroundColor($theme["bg"]);
+$im->setImageFormat("jpg");
+
+$noise = [
+	imagick::NOISE_GAUSSIAN,
+	imagick::NOISE_LAPLACIAN
+];
+
+$distort = [
+	imagick::DISTORTION_AFFINE,
+	imagick::DISTORTION_SHEPARDS
+];
+
+$i = 0;
+for($y=0; $y<4; $y++){
+	
+	for($x=0; $x<4; $x++){
+		
+		$tmp = new Imagick("./data/captcha/" . $grid[0][$i][0] . "/" . random_int(1, $grid[0][$i][1]) . ".png");
+		
+		// convert transparency correctly
+		$tmp->setImageBackgroundColor("black");
+		$tmp->setImageAlphaChannel(Imagick::ALPHACHANNEL_REMOVE);
+
+		// distort $tmp
+		$tmp->distortImage(
+			$distort[random_int(0,1)],
+			[
+				0, 0,
+				random_int(-15, 15), random_int(-15, 15),
+				
+				100, 0,
+				random_int(80, 120), random_int(-15, 15),
+				
+				100, 100,
+				random_int(80, 120), random_int(80, 120),
+				
+				0, 100,
+				random_int(-15, 15), random_int(80, 120)
+			],
+			false
+		);
+		
+		// append image
+		$im->compositeImage($tmp->getImage(), Imagick::COMPOSITE_DEFAULT, $x * 100, $y * 100);
+		
+		$i++;
+	}
+}
+
+// add noise
+$im->addNoiseImage($noise[random_int(0, 1)]);
+
+// expand top of image
+$im->setImageGravity(Imagick::GRAVITY_SOUTH);
+$im->chopImage(0, -27, 400, 400);
+$im->extentImage(0, 0, 0, -27);
+
+// add text
+$draw = new ImagickDraw();
+$draw->setFontSize(20);
+$draw->setFillColor($theme["fg"]);
+//$draw->setTextAntialias(false);
+$draw->setFont("./data/captcha/font.ttf");
+
+$text = "Pick " . $grid[1] . " images of " . str_replace("_", " ", $grid[2]);
+
+$pos = 200 - ($im->queryFontMetrics($draw, $text)["textWidth"] / 2);
+
+for($i=0; $i<strlen($text); $i++){
+	
+	$im->annotateImage(
+		$draw,
+		$pos,
+		20,
+		random_int(-15, 15),
+		$text[$i]
+	);
+	
+	$pos += $im->queryFontMetrics($draw, $text[$i])["textWidth"];
+		
+}
+
+$im->setFormat("jpeg");
+$im->setImageCompressionQuality(90);
+$im->setImageCompression(Imagick::COMPRESSION_JPEG2000);
+echo $im->getImageBlob();