Initial Commit

iTechSharp/iTextSharp/text/pdf/OutputStreamEncryption.cs

@@ -0,0 +1,170 @@
+using System;
+using System.IO;
+using iTextSharp.text.pdf.crypto;
+/*
+ * $Id: OutputStreamEncryption.cs,v 1.3 2007/04/29 13:57:07 psoares33 Exp $
+ *
+ * Copyright 2006 Paulo Soares
+ *
+ * The contents of this file are subject to the Mozilla Public License Version 1.1
+ * (the "License"); you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the License.
+ *
+ * The Original Code is 'iText, a free JAVA-PDF library'.
+ *
+ * The Initial Developer of the Original Code is Bruno Lowagie. Portions created by
+ * the Initial Developer are Copyright (C) 1999, 2000, 2001, 2002 by Bruno Lowagie.
+ * All Rights Reserved.
+ * Co-Developer of the code is Paulo Soares. Portions created by the Co-Developer
+ * are Copyright (C) 2000, 2001, 2002 by Paulo Soares. All Rights Reserved.
+ *
+ * Contributor(s): all the names of the contributors are added in the source code
+ * where applicable.
+ *
+ * Alternatively, the contents of this file may be used under the terms of the
+ * LGPL license (the "GNU LIBRARY GENERAL PUBLIC LICENSE"), in which case the
+ * provisions of LGPL are applicable instead of those above.  If you wish to
+ * allow use of your version of this file only under the terms of the LGPL
+ * License and not to allow others to use your version of this file under
+ * the MPL, indicate your decision by deleting the provisions above and
+ * replace them with the notice and other provisions required by the LGPL.
+ * If you do not delete the provisions above, a recipient may use your version
+ * of this file under either the MPL or the GNU LIBRARY GENERAL PUBLIC LICENSE.
+ *
+ * This library is free software; you can redistribute it and/or modify it
+ * under the terms of the MPL as stated above or under the terms of the GNU
+ * Library General Public License as published by the Free Software Foundation;
+ * either version 2 of the License, or any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU Library general Public License for more
+ * details.
+ *
+ * If you didn't download this code from the following link, you should check if
+ * you aren't using an obsolete version:
+ * http://www.lowagie.com/iText/
+ */
+
+namespace iTextSharp.text.pdf {
+    public class OutputStreamEncryption : Stream {
+    protected Stream outc;
+    protected ARCFOUREncryption arcfour;
+    protected AESCipher cipher;
+    private byte[] buf = new byte[1];
+    private const int AES_128 = 4;
+    private bool aes;
+    private bool finished;
+
+        public OutputStreamEncryption(Stream outc, byte[] key, int off, int len, int revision) {
+            this.outc = outc;
+            aes = revision == AES_128;
+            if (aes) {
+                byte[] iv = IVGenerator.GetIV();
+                byte[] nkey = new byte[len];
+                System.Array.Copy(key, off, nkey, 0, len);
+                cipher = new AESCipher(true, nkey, iv);
+                Write(iv, 0, iv.Length);
+            }
+            else {
+                arcfour = new ARCFOUREncryption();
+                arcfour.PrepareARCFOURKey(key, off, len);
+            }
+        }  
+
+        public OutputStreamEncryption(Stream outc, byte[] key, int revision) : this(outc, key, 0, key.Length, revision) {
+        }
+
+        public override bool CanRead {
+            get {
+                return false;
+            }
+        }
+    
+        public override bool CanSeek {
+            get {
+                return false;
+            }
+        }
+    
+        public override bool CanWrite {
+            get {
+                return true;
+            }
+        }
+    
+        public override long Length {
+            get {
+                throw new NotSupportedException();
+            }
+        }
+    
+        public override long Position {
+            get {
+                throw new NotSupportedException();
+            }
+            set {
+                throw new NotSupportedException();
+            }
+        }
+    
+        public override void Flush() {
+            outc.Flush();
+        }
+    
+        public override int Read(byte[] buffer, int offset, int count) {
+            throw new NotSupportedException();
+        }
+    
+        public override long Seek(long offset, SeekOrigin origin) {
+            throw new NotSupportedException();
+        }
+    
+        public override void SetLength(long value) {
+            throw new NotSupportedException();
+        }
+    
+        public override void Write(byte[] b, int off, int len) {
+            if (aes) {
+                byte[] b2 = cipher.Update(b, off, len);
+                if (b2 == null || b2.Length == 0)
+                    return;
+                outc.Write(b2, 0, b2.Length);
+            }
+            else {
+                byte[] b2 = new byte[Math.Min(len, 4192)];
+                while (len > 0) {
+                    int sz = Math.Min(len, b2.Length);
+                    arcfour.EncryptARCFOUR(b, off, sz, b2, 0);
+                    outc.Write(b2, 0, sz);
+                    len -= sz;
+                    off += sz;
+                }
+            }
+        }
+    
+        public override void Close() {
+            Finish();
+            outc.Close();
+        }
+    
+        public override void WriteByte(byte value) {
+            buf[0] = value;
+            Write(buf, 0, 1);
+        }
+
+        public void Finish() {
+            if (!finished) {
+                finished = true;
+                if (aes) {
+                    byte[] b = cipher.DoFinal();
+                    outc.Write(b, 0, b.Length);
+                }
+            }
+        }
+    }
+}