Safe check all formats

Author: automata

lib/exif/ExifImage.js

@@ -427,6 +427,7 @@ ExifImage.prototype.extractExifData = function (data, start, length) {
 
     debug("Makernote IFD parsed",exifData.makernote);
   }
+
 };
 
 ExifImage.prototype.extractExifEntry = function (data, entryOffset, tiffOffset, isBigEndian, tags) {
@@ -461,14 +462,14 @@ ExifImage.prototype.extractExifEntry = function (data, entryOffset, tiffOffset,
   } else {
     return false;
   }
-
   switch (entry.format) {
 
     case 0x0001: // unsigned byte, 1 byte per component
       entry.valueOffset = (entry.components <= 4) ? entryOffset + 8 : data.getLong(entryOffset + 8, isBigEndian) + tiffOffset;
       for (var i = 0; i < entry.components; i++) {
-        if (data.getByte(entry.valueOffset + i)) {
-          entry.value.push(data.getByte(entry.valueOffset + i));
+        var value = data.getByte(entry.valueOffset + i);
+        if (value) {
+          entry.value.push(value);
         } else {
           break;
         }
@@ -477,33 +478,59 @@ ExifImage.prototype.extractExifEntry = function (data, entryOffset, tiffOffset,
 
     case 0x0002: // ascii strings, 1 byte per component
       entry.valueOffset = (entry.components <= 4) ? entryOffset + 8 : data.getLong(entryOffset + 8, isBigEndian) + tiffOffset;
+
       entry.value = data.getString(entry.valueOffset, entry.components);
       if (entry.value[entry.value.length - 1] === "\u0000") // Trim null terminated strings
         entry.value = entry.value.substring(0, entry.value.length - 1);
       break;
 
     case 0x0003: // unsigned short, 2 byte per component
       entry.valueOffset = (entry.components <= 2) ? entryOffset + 8 : data.getLong(entryOffset + 8, isBigEndian) + tiffOffset;
-      for (var i = 0; i < entry.components; i++)
-        entry.value.push(data.getShort(entry.valueOffset + i * 2, isBigEndian));
+      for (var i = 0; i < entry.components; i++) {
+        var value = data.getShort(entry.valueOffset + i * 2, isBigEndian);
+        if (value) {
+          entry.value.push(value);
+        } else {
+          break;
+        }
+      }
       break;
 
     case 0x0004: // unsigned long, 4 byte per component
       entry.valueOffset = (entry.components == 1) ? entryOffset + 8 : data.getLong(entryOffset + 8, isBigEndian) + tiffOffset;
-      for (var i = 0; i < entry.components; i++)
-        entry.value.push(data.getLong(entry.valueOffset + i * 4, isBigEndian));
+      for (var i = 0; i < entry.components; i++) {
+        var value = data.getLong(entry.valueOffset + i * 4, isBigEndian);
+        if (value) {
+          entry.value.push(value);
+        } else {
+          break;
+        }
+      }
       break;
 
     case 0x0005: // unsigned rational, 8 byte per component (4 byte numerator and 4 byte denominator)
       entry.valueOffset = data.getLong(entryOffset + 8, isBigEndian) + tiffOffset;
-      for (var i = 0; i < entry.components; i++)
-        entry.value.push(data.getLong(entry.valueOffset + i * 8, isBigEndian) / data.getLong(entry.valueOffset + i * 8 + 4, isBigEndian));
+      for (var i = 0; i < entry.components; i++) {
+        var num = data.getLong(entry.valueOffset + i * 8, isBigEndian);
+        var den = data.getLong(entry.valueOffset + i * 8 + 4, isBigEndian);
+        if (num && den && den > 0) {
+          entry.value.push(num / den);
+        } else {
+          break;
+        }
+      }
       break;
 
     case 0x0006: // signed byte, 1 byte per component
       entry.valueOffset = (entry.components <= 4) ? entryOffset + 8 : data.getLong(entryOffset + 8, isBigEndian) + tiffOffset;
-      for (var i = 0; i < entry.components; i++)
-        entry.value.push(data.getSignedByte(entry.valueOffset + i));
+      for (var i = 0; i < entry.components; i++) {
+        var value = data.getSignedByte(entry.valueOffset + i);
+        if (value) {
+          entry.value.push(value);
+        } else {
+          break;
+        }
+      }
       break;
 
     case 0x0007: // undefined, 1 byte per component
@@ -513,20 +540,39 @@ ExifImage.prototype.extractExifEntry = function (data, entryOffset, tiffOffset,
 
     case 0x0008: // signed short, 2 byte per component
       entry.valueOffset = (entry.components <= 2) ? entryOffset + 8 : data.getLong(entryOffset + 8, isBigEndian) + tiffOffset;
-      for (var i = 0; i < entry.components; i++)
-        entry.value.push(data.getSignedShort(entry.valueOffset + i * 2, isBigEndian));
+      for (var i = 0; i < entry.components; i++) {
+        var value = data.getSignedShort(entry.valueOffset + i * 2, isBigEndian);
+        if (value) {
+          entry.value.push(value);
+        } else {
+          break;
+        }
+      }
       break;
 
     case 0x0009: // signed long, 4 byte per component
       entry.valueOffset = (entry.components == 1) ? entryOffset + 8 : data.getLong(entryOffset + 8, isBigEndian) + tiffOffset;
-      for (var i = 0; i < entry.components; i++)
-        entry.value.push(data.getSignedLong(entry.valueOffset + i * 4, isBigEndian));
+      for (var i = 0; i < entry.components; i++) {
+        var value = data.getSignedLong(entry.valueOffset + i * 4, isBigEndian);
+        if (value) {
+          entry.value.push(value);
+        } else {
+          break;
+        }
+      }
       break;
 
     case 0x000A: // signed rational, 8 byte per component (4 byte numerator and 4 byte denominator)
       entry.valueOffset = data.getLong(entryOffset + 8, isBigEndian) + tiffOffset;
-      for (var i = 0; i < entry.components; i++)
-        entry.value.push(data.getSignedLong(entry.valueOffset + i * 8, isBigEndian) / data.getSignedLong(entry.valueOffset + i * 8 + 4, isBigEndian));
+      for (var i = 0; i < entry.components; i++) {
+        var num = data.getSignedLong(entry.valueOffset + i * 8, isBigEndian);
+        var den = data.getSignedLong(entry.valueOffset + i * 8 + 4, isBigEndian);
+        if (num && den && den > 0) {
+          entry.value.push(num / den);
+        } else {
+          break;
+        }
+      }
       break;
 
     default: