[EGIT] [website/www] master 02/02: MEDIUM: shot: Find extension based on exif, not by magic signature

[Bertrand Jacquin]

beber pushed a commit to branch master.

http://git.enlightenment.org/website/www.git/commit/?id=1d551927f77ad7c62ce42f2ec7971ae94e58dc37

commit 1d551927f77ad7c62ce42f2ec7971ae94e58dc37
Author: Bertrand Jacquin <be...@meleeweb.net>
Date:   Tue Apr 29 21:53:25 2014 +0200

    MEDIUM: shot: Find extension based on exif, not by magic signature
---
 public_html/shot.php | 72 +++++++++++++++++++++++++++-------------------------
 1 file changed, 37 insertions(+), 35 deletions(-)

diff --git a/public_html/shot.php b/public_html/shot.php
index 0ef7d64..a793571 100644
--- a/public_html/shot.php
+++ b/public_html/shot.php
@@ -6,23 +6,20 @@ function get_ip()
     return $ip;
 }
 
-function extn($str) {
-  $i = strrpos($str,".");
-  if (!$i) { return ""; }
-  $l = strlen($str) - $i;
-  $ext = substr($str,$i+1,$l);
-  return $ext;
-}
-
 function dothumb($f, $thumb, $new_w, $new_h) {
-  $ext = extn($f);
-  if (!strcmp("jpg", $ext))
-    $src_img = imagecreatefromjpeg($f);
-  if (!strcmp("png", $ext))
-    $src_img = imagecreatefrompng($f);
+  $image_type = exif_imagetype($f);
 
-  if (!$src_img)
-    return false;
+  switch ($image_type) {
+    case IMAGETYPE_JPEG:
+      $src_img = imagecreatefromjpeg($f);
+      break;
+    case IMAGETYPE_PNG:
+      $src_img = imagecreatefrompng($f);
+      break;
+    default:
+      return false;
+      break;
+  }
 
   $old_x = imageSX($src_img);
   $old_y = imageSY($src_img);
@@ -39,10 +36,16 @@ function dothumb($f, $thumb, $new_w, $new_h) {
   $dst_img = ImageCreateTrueColor($thumb_w, $thumb_h);
   imagecopyresampled($dst_img, $src_img, 0, 0, 0, 0,
                     $thumb_w, $thumb_h, $old_x, $old_y);
-  if (!strcmp("png", $ext))
-    imagepng($dst_img, $thumb);
-  else
-    imagejpeg($dst_img, $thumb);
+
+  switch ($image_type) {
+    case IMAGETYPE_JPEG:
+      imagejpeg($dst_img, $thumb);
+      break;
+    case IMAGETYPE_PNG:
+      imagepng($dst_img, $thumb);
+      break;
+  }
+
   imagedestroy($dst_img);
   imagedestroy($src_img);
 }
@@ -50,23 +53,22 @@ function dothumb($f, $thumb, $new_w, $new_h) {
 ob_start();
 ############ limit - 6 mb.
 $data = file_get_contents('php://input', NULL, NULL, 0, 6 * 1024 * 1024);
-############ magic jpeg signature
-$jpeg_match = "\xff\xd8\xff\xe0";
-$jpeg_magic = substr($data, 0, 4);
-############ magic png signature
-$png_match = "\x89\x50\x4e\x47";
-$png_magic = substr($data, 0, 4);
+$image_type = exif_imagetype($data);
 
-############ base on signaure, add file extension
-$ext = ".unknown";
-if ($jpeg_match == $jpeg_magic) $ext = ".jpg";
-else if ($png_match == $png_magic) $ext = ".png";
-############ not a correct matching file - abort
-else {
-  header("HTTP/1.1 400 Bad Request");
-  echo "Invalid File Format";
-  ob_end_flush();
-  die();
+case ($image_type) {
+  case IMAGETYPE_JPEG:
+    $ext = ".jpg";
+    break;
+  case IMAGETYPE_PNG:
+    $ext = ".png";
+    break;
+  default:
+    ############ not a correct matching file - abort
+    header("HTTP/1.1 400 Bad Request");
+    echo "Invalid File Format";
+    ob_end_flush();
+    die();
+    break;
 }
 
 ############ get a unique name

--