jaxws/src/java.xml.ws/share/classes/com/sun/xml/internal/messaging/saaj/packaging/mime/util/BASE64DecoderStream.java - platform/libcore - Git at Google

 /*
  * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this
  * particular file as subject to the "Classpath" exception as provided
  * by Oracle in the LICENSE file that accompanied this code.
  *
  * This code 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 General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */

 /*
  * @(#)BASE64DecoderStream.java       1.8 02/03/27
  */


 package com.sun.xml.internal.messaging.saaj.packaging.mime.util;

 import java.io.*;

 /**
  * This class implements a BASE64 Decoder. It is implemented as
  * a FilterInputStream, so one can just wrap this class around
  * any input stream and read bytes from this filter. The decoding
  * is done as the bytes are read out.
  *
  * @author John Mani
  * @author Bill Shannon
  */

 public class BASE64DecoderStream extends FilterInputStream {
     private byte[] buffer;      // cache of decoded bytes
     private int bufsize = 0;    // size of the cache
     private int index = 0;      // index into the cache

     /**
      * Create a BASE64 decoder that decodes the specified input stream
      * @param in        the input stream
      */
     public BASE64DecoderStream(InputStream in) {
         super(in);
         buffer = new byte[3];
     }

     /**
      * Read the next decoded byte from this input stream. The byte
      * is returned as an <code>int</code> in the range <code>0</code>
      * to <code>255</code>. If no byte is available because the end of
      * the stream has been reached, the value <code>-1</code> is returned.
      * This method blocks until input data is available, the end of the
      * stream is detected, or an exception is thrown.
      *
      * @return     next byte of data, or <code>-1</code> if the end of the
      *             stream is reached.
      * @exception  IOException  if an I/O error occurs.
      * @see        java.io.FilterInputStream#in
      */
     @Override
     public int read() throws IOException {
         if (index >= bufsize) {
             decode(); // Fills up buffer
             if (bufsize == 0) // buffer is empty
                 return -1;
             index = 0; // reset index into buffer
         }
         return buffer[index++] & 0xff; // Zero off the MSB
     }

     /**
      * Reads up to <code>len</code> decoded bytes of data from this input stream
      * into an array of bytes. This method blocks until some input is
      * available.
      * <p>
      *
      * @param      buf   the buffer into which the data is read.
      * @param      off   the start offset of the data.
      * @param      len   the maximum number of bytes read.
      * @return     the total number of bytes read into the buffer, or
      *             <code>-1</code> if there is no more data because the end of
      *             the stream has been reached.
      * @exception  IOException  if an I/O error occurs.
      */
     @Override
     public int read(byte[] buf, int off, int len) throws IOException {
         int i, c;
         for (i = 0; i < len; i++) {
             if ((c = read()) == -1) {
                 if (i == 0) // At end of stream, so we should
                     i = -1; // return -1 , NOT 0.
                 break;
             }
             buf[off+i] = (byte)c;
         }

         return i;
     }

     /**
      * Tests if this input stream supports marks. Currently this class
      * does not support marks
      */
     @Override
     public boolean markSupported() {
         return false; // Maybe later ..
     }

     /**
      * Returns the number of bytes that can be read from this input
      * stream without blocking. However, this figure is only
      * a close approximation in case the original encoded stream
      * contains embedded CRLFs; since the CRLFs are discarded, not decoded
      */
     @Override
     public int available() throws IOException {
          // This is only an estimate, since in.available()
          // might include CRLFs too ..
          return ((in.available() * 3)/4 + (bufsize-index));
     }

     /**
      * This character array provides the character to value map
      * based on RFC1521.
      */
     private final static char pem_array[] = {
         'A','B','C','D','E','F','G','H', // 0
         'I','J','K','L','M','N','O','P', // 1
         'Q','R','S','T','U','V','W','X', // 2
         'Y','Z','a','b','c','d','e','f', // 3
         'g','h','i','j','k','l','m','n', // 4
         'o','p','q','r','s','t','u','v', // 5
         'w','x','y','z','0','1','2','3', // 6
         '4','5','6','7','8','9','+','/'  // 7
     };

     private final static byte pem_convert_array[] = new byte[256];

     static {
         for (int i = 0; i < 255; i++)
             pem_convert_array[i] = -1;
         for(int i = 0; i < pem_array.length; i++)
             pem_convert_array[pem_array[i]] = (byte) i;
     }

     /* The decoder algorithm */
     private byte[] decode_buffer = new byte[4];
     private void decode() throws IOException {
         bufsize = 0;
         /*
          * We need 4 valid base64 characters before we start decoding.
          * We skip anything that's not a valid base64 character (usually
          * just CRLF).
          */
         int got = 0;
         while (got < 4) {
             int i = in.read();
             if (i == -1) {
                 if (got == 0)
                     return;     // EOF before any data is ok
                 throw new IOException("Error in encoded stream, got " + got);
             }
             if (i >= 0 && i < 256 && i == '=' || pem_convert_array[i] != -1)
                 decode_buffer[got++] = (byte)i;
         }

         byte a, b;
         a = pem_convert_array[decode_buffer[0] & 0xff];
         b = pem_convert_array[decode_buffer[1] & 0xff];
         // The first decoded byte
         buffer[bufsize++] = (byte)(((a << 2) & 0xfc) | ((b >>> 4) & 3));

         if (decode_buffer[2] == '=') // End of this BASE64 encoding
             return;
         a = b;
         b = pem_convert_array[decode_buffer[2] & 0xff];
         // The second decoded byte
         buffer[bufsize++] = (byte)(((a << 4) & 0xf0) | ((b >>> 2) & 0xf));

         if (decode_buffer[3] == '=') // End of this BASE64 encoding
             return;
         a = b;
         b = pem_convert_array[decode_buffer[3] & 0xff];
         // The third decoded byte
         buffer[bufsize++] = (byte)(((a << 6) & 0xc0) | (b & 0x3f));
     }

     /**
      * Base64 decode a byte array.  No line breaks are allowed.
      * This method is suitable for short strings, such as those
      * in the IMAP AUTHENTICATE protocol, but not to decode the
      * entire content of a MIME part.
      *
      * @param inbuf byte array to decode
      *
      * @return decoded byte array
      *
      * NOTE: inbuf may only contain valid base64 characters.
      *       Whitespace is not ignored.
      */
     public static byte[] decode(byte[] inbuf) {
         int size = (inbuf.length / 4) * 3;
         if (size == 0)
             return inbuf;

         if (inbuf[inbuf.length - 1] == '=') {
             size--;
             if (inbuf[inbuf.length - 2] == '=')
                 size--;
         }
         byte[] outbuf = new byte[size];

         int inpos = 0, outpos = 0;
         size = inbuf.length;
         while (size > 0) {
             byte a, b;
             a = pem_convert_array[inbuf[inpos++] & 0xff];
             b = pem_convert_array[inbuf[inpos++] & 0xff];
             // The first decoded byte
             outbuf[outpos++] = (byte)(((a << 2) & 0xfc) | ((b >>> 4) & 3));

             if (inbuf[inpos] == '=') // End of this BASE64 encoding
                 return outbuf;
             a = b;
             b = pem_convert_array[inbuf[inpos++] & 0xff];
             // The second decoded byte
             outbuf[outpos++] = (byte)(((a << 4) & 0xf0) | ((b >>> 2) & 0xf));

             if (inbuf[inpos] == '=') // End of this BASE64 encoding
                 return outbuf;
             a = b;
             b = pem_convert_array[inbuf[inpos++] & 0xff];
             // The third decoded byte
             outbuf[outpos++] = (byte)(((a << 6) & 0xc0) | (b & 0x3f));
             size -= 4;
         }
         return outbuf;
     }

     /*** begin TEST program ***
     public static void main(String argv[]) throws Exception {
         FileInputStream infile = new FileInputStream(argv[0]);
         BASE64DecoderStream decoder = new BASE64DecoderStream(infile);
         int c;

         while ((c = decoder.read()) != -1)
             System.out.print((char)c);
         System.out.flush();
     }
     *** end TEST program ***/
 }
	/*
	* Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code 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 General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	/*
	* @(#)BASE64DecoderStream.java 1.8 02/03/27
	*/



	package com.sun.xml.internal.messaging.saaj.packaging.mime.util;

	import java.io.*;

	/**
	* This class implements a BASE64 Decoder. It is implemented as
	* a FilterInputStream, so one can just wrap this class around
	* any input stream and read bytes from this filter. The decoding
	* is done as the bytes are read out.
	*
	* @author John Mani
	* @author Bill Shannon
	*/

	public class BASE64DecoderStream extends FilterInputStream {
	private byte[] buffer; // cache of decoded bytes
	private int bufsize = 0; // size of the cache
	private int index = 0; // index into the cache

	/**
	* Create a BASE64 decoder that decodes the specified input stream
	* @param in the input stream
	*/
	public BASE64DecoderStream(InputStream in) {
	super(in);
	buffer = new byte[3];
	}

	/**
	* Read the next decoded byte from this input stream. The byte
	* is returned as an <code>int</code> in the range <code>0</code>
	* to <code>255</code>. If no byte is available because the end of
	* the stream has been reached, the value <code>-1</code> is returned.
	* This method blocks until input data is available, the end of the
	* stream is detected, or an exception is thrown.
	*
	* @return next byte of data, or <code>-1</code> if the end of the
	* stream is reached.
	* @exception IOException if an I/O error occurs.
	* @see java.io.FilterInputStream#in
	*/
	@Override
	public int read() throws IOException {
	if (index >= bufsize) {
	decode(); // Fills up buffer
	if (bufsize == 0) // buffer is empty
	return -1;
	index = 0; // reset index into buffer
	}
	return buffer[index++] & 0xff; // Zero off the MSB
	}

	/**
	* Reads up to <code>len</code> decoded bytes of data from this input stream
	* into an array of bytes. This method blocks until some input is
	* available.
	* <p>
	*
	* @param buf the buffer into which the data is read.
	* @param off the start offset of the data.
	* @param len the maximum number of bytes read.
	* @return the total number of bytes read into the buffer, or
	* <code>-1</code> if there is no more data because the end of
	* the stream has been reached.
	* @exception IOException if an I/O error occurs.
	*/
	@Override
	public int read(byte[] buf, int off, int len) throws IOException {
	int i, c;
	for (i = 0; i < len; i++) {
	if ((c = read()) == -1) {
	if (i == 0) // At end of stream, so we should
	i = -1; // return -1 , NOT 0.
	break;
	}
	buf[off+i] = (byte)c;
	}

	return i;
	}

	/**
	* Tests if this input stream supports marks. Currently this class
	* does not support marks
	*/
	@Override
	public boolean markSupported() {
	return false; // Maybe later ..
	}

	/**
	* Returns the number of bytes that can be read from this input
	* stream without blocking. However, this figure is only
	* a close approximation in case the original encoded stream
	* contains embedded CRLFs; since the CRLFs are discarded, not decoded
	*/
	@Override
	public int available() throws IOException {
	// This is only an estimate, since in.available()
	// might include CRLFs too ..
	return ((in.available() * 3)/4 + (bufsize-index));
	}

	/**
	* This character array provides the character to value map
	* based on RFC1521.
	*/
	private final static char pem_array[] = {
	'A','B','C','D','E','F','G','H', // 0
	'I','J','K','L','M','N','O','P', // 1
	'Q','R','S','T','U','V','W','X', // 2
	'Y','Z','a','b','c','d','e','f', // 3
	'g','h','i','j','k','l','m','n', // 4
	'o','p','q','r','s','t','u','v', // 5
	'w','x','y','z','0','1','2','3', // 6
	'4','5','6','7','8','9','+','/' // 7
	};

	private final static byte pem_convert_array[] = new byte[256];

	static {
	for (int i = 0; i < 255; i++)
	pem_convert_array[i] = -1;
	for(int i = 0; i < pem_array.length; i++)
	pem_convert_array[pem_array[i]] = (byte) i;
	}

	/* The decoder algorithm */
	private byte[] decode_buffer = new byte[4];
	private void decode() throws IOException {
	bufsize = 0;
	/*
	* We need 4 valid base64 characters before we start decoding.
	* We skip anything that's not a valid base64 character (usually
	* just CRLF).
	*/
	int got = 0;
	while (got < 4) {
	int i = in.read();
	if (i == -1) {
	if (got == 0)
	return; // EOF before any data is ok
	throw new IOException("Error in encoded stream, got " + got);
	}
	if (i >= 0 && i < 256 && i == '=' \|\| pem_convert_array[i] != -1)
	decode_buffer[got++] = (byte)i;
	}

	byte a, b;
	a = pem_convert_array[decode_buffer[0] & 0xff];
	b = pem_convert_array[decode_buffer[1] & 0xff];
	// The first decoded byte
	buffer[bufsize++] = (byte)(((a << 2) & 0xfc) \| ((b >>> 4) & 3));

	if (decode_buffer[2] == '=') // End of this BASE64 encoding
	return;
	a = b;
	b = pem_convert_array[decode_buffer[2] & 0xff];
	// The second decoded byte
	buffer[bufsize++] = (byte)(((a << 4) & 0xf0) \| ((b >>> 2) & 0xf));

	if (decode_buffer[3] == '=') // End of this BASE64 encoding
	return;
	a = b;
	b = pem_convert_array[decode_buffer[3] & 0xff];
	// The third decoded byte
	buffer[bufsize++] = (byte)(((a << 6) & 0xc0) \| (b & 0x3f));
	}

	/**
	* Base64 decode a byte array. No line breaks are allowed.
	* This method is suitable for short strings, such as those
	* in the IMAP AUTHENTICATE protocol, but not to decode the
	* entire content of a MIME part.
	*
	* @param inbuf byte array to decode
	*
	* @return decoded byte array
	*
	* NOTE: inbuf may only contain valid base64 characters.
	* Whitespace is not ignored.
	*/
	public static byte[] decode(byte[] inbuf) {
	int size = (inbuf.length / 4) * 3;
	if (size == 0)
	return inbuf;

	if (inbuf[inbuf.length - 1] == '=') {
	size--;
	if (inbuf[inbuf.length - 2] == '=')
	size--;
	}
	byte[] outbuf = new byte[size];

	int inpos = 0, outpos = 0;
	size = inbuf.length;
	while (size > 0) {
	byte a, b;
	a = pem_convert_array[inbuf[inpos++] & 0xff];
	b = pem_convert_array[inbuf[inpos++] & 0xff];
	// The first decoded byte
	outbuf[outpos++] = (byte)(((a << 2) & 0xfc) \| ((b >>> 4) & 3));

	if (inbuf[inpos] == '=') // End of this BASE64 encoding
	return outbuf;
	a = b;
	b = pem_convert_array[inbuf[inpos++] & 0xff];
	// The second decoded byte
	outbuf[outpos++] = (byte)(((a << 4) & 0xf0) \| ((b >>> 2) & 0xf));

	if (inbuf[inpos] == '=') // End of this BASE64 encoding
	return outbuf;
	a = b;
	b = pem_convert_array[inbuf[inpos++] & 0xff];
	// The third decoded byte
	outbuf[outpos++] = (byte)(((a << 6) & 0xc0) \| (b & 0x3f));
	size -= 4;
	}
	return outbuf;
	}

	/* begin TEST program *
	public static void main(String argv[]) throws Exception {
	FileInputStream infile = new FileInputStream(argv[0]);
	BASE64DecoderStream decoder = new BASE64DecoderStream(infile);
	int c;

	while ((c = decoder.read()) != -1)
	System.out.print((char)c);
	System.out.flush();
	}
	* end TEST program */
	}