r27016 - trunk/freenet/src/freenet/clients/http/filter

Author: kurmiashish
Date: 2009-04-18 19:33:36 +0000 (Sat, 18 Apr 2009)
New Revision: 27016

Added:
   trunk/freenet/src/freenet/clients/http/filter/BMPFilter.java
Log:


Added: trunk/freenet/src/freenet/clients/http/filter/BMPFilter.java
===================================================================
--- trunk/freenet/src/freenet/clients/http/filter/BMPFilter.java	                        (rev 0)
+++ trunk/freenet/src/freenet/clients/http/filter/BMPFilter.java	2009-04-18 19:33:36 UTC (rev 27016)
@@ -0,0 +1,201 @@
+/* This code is part of Freenet. It is distributed under the GNU General
+ * Public License, version 2 (or at your option any later version). See
+ * http://www.gnu.org/ for further details of the GPL. */
+package freenet.clients.http.filter;
+
+import java.io.BufferedInputStream;
+import java.io.DataInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Arrays;
+import java.util.HashMap;
+
+import freenet.l10n.L10n;
+import freenet.support.HTMLNode;
+import freenet.support.api.Bucket;
+import freenet.support.api.BucketFactory;
+import freenet.support.io.Closer;
+
+/**
+ * This class would verify whether the BMP header is valid or not
+ Reference:
+ http://www.fastgraph.com/help/bmp_header_format.html
+ http://en.wikipedia.org/wiki/BMP_file_format
+ */
+public class BMPFilter implements ContentDataFilter {
+
+	
+	static final byte[] bmpHeaderwindows =
+		{ (byte)'B', (byte)'M'};
+	
+		static final byte[] bmpHeaderos2bArray =
+		{ (byte)'B', (byte)'A'};
+
+		static final byte[] bmpHeaderos2cIcon =
+		{ (byte)'C', (byte)'I'};
+
+
+		static final byte[] bmpHeaderos2cPointer =
+		{ (byte)'C', (byte)'P'};
+
+
+		static final byte[] bmpHeaderos2Icon =
+		{ (byte)'I', (byte)'C'};
+
+
+		static final byte[] bmpHeaderos2Pointer =
+		{ (byte)'P', (byte)'T'};
+
+
+    private int unsignedByte(byte b)
+    {
+        if (b >= 0)
+            return b;
+        else
+            return 256+b;
+    }
+
+
+  public int readInt(DataInputStream dis) throws IOException
+  {
+    int result;
+    byte[] data = new byte[4];
+
+     result = dis.read(data);
+     if (result < 0) // end of file reached
+         throw new EOFException();
+
+     result = (unsignedByte(data[2]) << 16) | (unsignedByte(data[1]) << 8) | unsignedByte(data[0]);
+     result|=(unsignedByte(data[3]) << 24);
+
+     return result;
+  }
+
+
+     public int readShort(DataInputStream dis) throws IOException
+    {
+        int result = dis.read();
+        if (result < 0)// end of file reached
+            throw new EOFException();
+
+        int r2 = is.read();
+        if (r2 < 0)// end of file reached
+            throw new EOFException();
+
+        return result | (r2*256);
+    }
+
+	
+	public Bucket readFilter(Bucket data, BucketFactory bf, String charset, HashMap<String, String> otherParams,
+	        FilterCallback cb) throws DataFilterException, IOException {
+		if(data.size() < 54) { // Size of the bmp header is 54
+			throwHeaderError(l10n("Too short file"), l10n("The file is too short to contain a bmp header"));
+		}
+		InputStream is = data.getInputStream();
+		BufferedInputStream bis = new BufferedInputStream(is);
+		DataInputStream dis = new DataInputStream(bis);
+		try {
+			
+		byte[] StartWord = new byte[2];
+		dis.readFully(StartWord);
+		if((!Arrays.equals(StartWord, bmpHeaderwindows)) && (!Arrays.equals(StartWord, bmpHeaderos2bArray)) && (!Arrays.equals(StartWord, bmpHeaderos2cIcon)) && (!Arrays.equals(StartWord, bmpHeaderos2cPointer)) && (!Arrays.equals(StartWord, bmpHeaderos2Icon)) && (!Arrays.equals(StartWord, bmpHeaderos2Pointer))) {	//Checking the first word
+				throwHeaderError(l10n("Invalid start word"), l10n("invalidHeader"));
+		}
+			
+			
+			
+		int fileSize = readInt(dis); // read total file size
+		byte[] skipbytes=new byte[4];
+		dis.readFully(skipbytes);
+        int headerSize = readInt(dis); // read file header size or pixel offset
+		if(headerSize<0) {
+					throwHeaderError(l10n("Invalid offset"), l10n("Image has invalid pixel offset of "+headerSize));
+		}
+		
+
+
+		int size_bitmapinfoheader=readInt(dis);
+		if(size_bitmapinfoheader!=40) {
+					throwHeaderError(l10n("Invalid Bit Map info header size"), l10n("Size of bitmap info header is not 40"));
+		}
+
+
+        int imageWidth = readInt(dis); // read width
+        int imageHeight = readInt(dis); // read height
+		if(imageWidth<0 || imageHeight<0) {
+					throwHeaderError(l10n("Invalid Dimensions"), l10n("The image has invalid width or height"));
+		}
+
+
+        
+		int no_plane=readShort(dis);
+		if(no_plane!=1) { // No of planes should be 1
+					throwHeaderError(l10n("Invalid no of plannes"), l10n("The image has "+no_plane+" planes"));
+		}
+				
+
+        int bitDepth = readShort(dis);
+		
+		// Bit depth should be 1,2,4,8,16 or 32.
+		if(bitDepth!=1 && bitDepth!=2 && bitDepth!=4 && bitDepth!=8 && bitDepth!=16 && bitDepth!=24 && bitDepth!=32) {
+					throwHeaderError(l10n("Invalid bit depth"), l10n("The bit depth field is set to"+bitDepth+". It is not of 1,2,4,8,16, and 32."));
+		}
+
+		int compression_type=readInt(dis);
+		if( !(compression_type>=0 && compression_type<=3) ) {
+					throwHeaderError(l10n("Invalid Compression type"), l10n("Compression type field is set to "+compression_type+" instead of 0-3"));
+		}
+			
+		int imagedatasize=readInt(dis);
+		if(fileSize!=headerSize+imagedatasize) {
+					throwHeaderError(l10n("Invalid File size"), l10n("File size is not matching to headersize+ imagedatasize"));
+		}
+
+		int horizontal_resolution=readInt(dis);
+		int vertical_resolution=readInt(dis);
+
+		if(horizontal_resolution<0 || vertical_resolution<0) {
+				throwHeaderError(l10n("Invalid resolution"), l10n("This image file has resolution of "+horizontal_resolution+"x"+vertical_resolution ));
+		}
+		if(compression_type==0) {
+		// Verifying the file size w.r.t. image dimensions(width and height), bitDepth with imagedatasize(including padding).
+			int bytesperline=(int)Math.ceil((imageWidth*bitDepth)/8);
+			int paddingperline=0;
+			if(bytesperline%4!=0) {
+						paddingperline=4-bytesperline%4;
+			}
+			int calculatedsize= (int)Math.ceil((imageWidth*imageHeight*bitDepth)/8)+paddingperline*imageHeight;
+			if(calculatedsize!=imagedatasize) {
+					throwHeaderError(l10n("Invalid size of image data"), l10n("The calculated image data size ("+calculatedsize+") is not matching with the actual size ("+imagedatasize+")" ));
+			}
+		}
+			
+
+
+			dis.close();
+		} finally {
+			Closer.close(dis);
+		}
+		return data;
+	}
+
+	private static String l10n(String key) {
+		return L10n.getString("BMPFilter."+key);
+	}
+
+	private void throwHeaderError(String shortReason, String reason) throws DataFilterException {
+		// Throw an exception
+		String message = l10n("notBMP");
+		if(reason != null) message += ' ' + reason;
+		if(shortReason != null)
+			message += " - (" + shortReason + ')';
+		throw new DataFilterException(shortReason, shortReason,
+				"<p>"+message+"</p>", new HTMLNode("p").addChild("#", message));
+	}
+
+	public Bucket writeFilter(Bucket data, BucketFactory bf, String charset, HashMap<String, String> otherParams,
+	        FilterCallback cb) throws DataFilterException, IOException {
+		return null;
+	}
+
+}