aoqi@0: /*
aoqi@0:  * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
aoqi@0:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0:  *
aoqi@0:  * This code is free software; you can redistribute it and/or modify it
aoqi@0:  * under the terms of the GNU General Public License version 2 only, as
aoqi@0:  * published by the Free Software Foundation.  Oracle designates this
aoqi@0:  * particular file as subject to the "Classpath" exception as provided
aoqi@0:  * by Oracle in the LICENSE file that accompanied this code.
aoqi@0:  *
aoqi@0:  * This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
aoqi@0:  * version 2 for more details (a copy is included in the LICENSE file that
aoqi@0:  * accompanied this code).
aoqi@0:  *
aoqi@0:  * You should have received a copy of the GNU General Public License version
aoqi@0:  * 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0:  *
aoqi@0:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0:  * or visit www.oracle.com if you need additional information or have any
aoqi@0:  * questions.
aoqi@0:  */
aoqi@0: 
aoqi@0: /* FROM mail.jar */
aoqi@0: package com.sun.xml.internal.org.jvnet.mimepull;
aoqi@0: 
aoqi@0: import java.io.*;
aoqi@0: 
aoqi@0: /**
aoqi@0:  * This class implements a UUDecoder. It is implemented as
aoqi@0:  * a FilterInputStream, so one can just wrap this class around
aoqi@0:  * any input stream and read bytes from this filter. The decoding
aoqi@0:  * is done as the bytes are read out.
aoqi@0:  *
aoqi@0:  * @author John Mani
aoqi@0:  * @author Bill Shannon
aoqi@0:  */
aoqi@0: 
aoqi@0: final class UUDecoderStream extends FilterInputStream {
aoqi@0:     private String name;
aoqi@0:     private int mode;
aoqi@0: 
aoqi@0:     private byte[] buffer = new byte[45]; // max decoded chars in a line = 45
aoqi@0:     private int bufsize = 0;    // size of the cache
aoqi@0:     private int index = 0;      // index into the cache
aoqi@0:     private boolean gotPrefix = false;
aoqi@0:     private boolean gotEnd = false;
aoqi@0:     private LineInputStream lin;
aoqi@0:     private boolean ignoreErrors;
aoqi@0:     private boolean ignoreMissingBeginEnd;
aoqi@0:     private String readAhead;
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Create a UUdecoder that decodes the specified input stream.
aoqi@0:      * The System property <code>mail.mime.uudecode.ignoreerrors</code>
aoqi@0:      * controls whether errors in the encoded data cause an exception
aoqi@0:      * or are ignored.  The default is false (errors cause exception).
aoqi@0:      * The System property <code>mail.mime.uudecode.ignoremissingbeginend</code>
aoqi@0:      * controls whether a missing begin or end line cause an exception
aoqi@0:      * or are ignored.  The default is false (errors cause exception).
aoqi@0:      * @param in        the input stream
aoqi@0:      */
aoqi@0:     public UUDecoderStream(InputStream in) {
aoqi@0:         super(in);
aoqi@0:         lin = new LineInputStream(in);
aoqi@0:         // default to false
aoqi@0:         ignoreErrors = PropUtil.getBooleanSystemProperty(
aoqi@0:             "mail.mime.uudecode.ignoreerrors", false);
aoqi@0:         // default to false
aoqi@0:         ignoreMissingBeginEnd = PropUtil.getBooleanSystemProperty(
aoqi@0:             "mail.mime.uudecode.ignoremissingbeginend", false);
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Create a UUdecoder that decodes the specified input stream.
aoqi@0:      * @param in                the input stream
aoqi@0:      * @param ignoreErrors      ignore errors?
aoqi@0:      * @param ignoreMissingBeginEnd     ignore missing begin or end?
aoqi@0:      */
aoqi@0:     public UUDecoderStream(InputStream in, boolean ignoreErrors,
aoqi@0:                                 boolean ignoreMissingBeginEnd) {
aoqi@0:         super(in);
aoqi@0:         lin = new LineInputStream(in);
aoqi@0:         this.ignoreErrors = ignoreErrors;
aoqi@0:         this.ignoreMissingBeginEnd = ignoreMissingBeginEnd;
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Read the next decoded byte from this input stream. The byte
aoqi@0:      * is returned as an <code>int</code> in the range <code>0</code>
aoqi@0:      * to <code>255</code>. If no byte is available because the end of
aoqi@0:      * the stream has been reached, the value <code>-1</code> is returned.
aoqi@0:      * This method blocks until input data is available, the end of the
aoqi@0:      * stream is detected, or an exception is thrown.
aoqi@0:      *
aoqi@0:      * @return     next byte of data, or <code>-1</code> if the end of
aoqi@0:      *             stream is reached.
aoqi@0:      * @exception  IOException  if an I/O error occurs.
aoqi@0:      * @see        java.io.FilterInputStream#in
aoqi@0:      */
aoqi@0:     @Override
aoqi@0:     public int read() throws IOException {
aoqi@0:         if (index >= bufsize) {
aoqi@0:             readPrefix();
aoqi@0:             if (!decode()) {
aoqi@0:                 return -1;
aoqi@0:             }
aoqi@0:             index = 0; // reset index into buffer
aoqi@0:         }
aoqi@0:         return buffer[index++] & 0xff; // return lower byte
aoqi@0:     }
aoqi@0: 
aoqi@0:     @Override
aoqi@0:     public int read(byte[] buf, int off, int len) throws IOException {
aoqi@0:         int i, c;
aoqi@0:         for (i = 0; i < len; i++) {
aoqi@0:             if ((c = read()) == -1) {
aoqi@0:                 if (i == 0) {// At end of stream, so we should
aoqi@0:                     i = -1; // return -1, NOT 0.
aoqi@0:                 }
aoqi@0:                 break;
aoqi@0:             }
aoqi@0:             buf[off+i] = (byte)c;
aoqi@0:         }
aoqi@0:         return i;
aoqi@0:     }
aoqi@0: 
aoqi@0:     @Override
aoqi@0:     public boolean markSupported() {
aoqi@0:         return false;
aoqi@0:     }
aoqi@0: 
aoqi@0:     @Override
aoqi@0:     public int available() throws IOException {
aoqi@0:          // This is only an estimate, since in.available()
aoqi@0:          // might include CRLFs too ..
aoqi@0:          return ((in.available() * 3)/4 + (bufsize-index));
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Get the "name" field from the prefix. This is meant to
aoqi@0:      * be the pathname of the decoded file
aoqi@0:      *
aoqi@0:      * @return     name of decoded file
aoqi@0:      * @exception  IOException  if an I/O error occurs.
aoqi@0:      */
aoqi@0:     public String getName() throws IOException {
aoqi@0:         readPrefix();
aoqi@0:         return name;
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Get the "mode" field from the prefix. This is the permission
aoqi@0:      * mode of the source file.
aoqi@0:      *
aoqi@0:      * @return     permission mode of source file
aoqi@0:      * @exception  IOException  if an I/O error occurs.
aoqi@0:      */
aoqi@0:     public int getMode() throws IOException {
aoqi@0:         readPrefix();
aoqi@0:         return mode;
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * UUencoded streams start off with the line:
aoqi@0:      *  "begin <mode> <filename>"
aoqi@0:      * Search for this prefix and gobble it up.
aoqi@0:      */
aoqi@0:     private void readPrefix() throws IOException {
aoqi@0:         if (gotPrefix) {
aoqi@0:             return;
aoqi@0:         }
aoqi@0: 
aoqi@0:         mode = 0666;            // defaults, overridden below
aoqi@0:         name = "encoder.buf";   // same default used by encoder
aoqi@0:         String line;
aoqi@0:         for (;;) {
aoqi@0:             // read till we get the prefix: "begin MODE FILENAME"
aoqi@0:             line = lin.readLine(); // NOTE: readLine consumes CRLF pairs too
aoqi@0:             if (line == null) {
aoqi@0:                 if (!ignoreMissingBeginEnd) {
aoqi@0:                     throw new DecodingException("UUDecoder: Missing begin");
aoqi@0:                 }
aoqi@0:                 // at EOF, fake it
aoqi@0:                 gotPrefix = true;
aoqi@0:                 gotEnd = true;
aoqi@0:                 break;
aoqi@0:             }
aoqi@0:             if (line.regionMatches(false, 0, "begin", 0, 5)) {
aoqi@0:                 try {
aoqi@0:                     mode = Integer.parseInt(line.substring(6,9));
aoqi@0:                 } catch (NumberFormatException ex) {
aoqi@0:                     if (!ignoreErrors) {
aoqi@0:                         throw new DecodingException(
aoqi@0:                                 "UUDecoder: Error in mode: " + ex.toString());
aoqi@0:                     }
aoqi@0:                 }
aoqi@0:                 if (line.length() > 10) {
aoqi@0:                     name = line.substring(10);
aoqi@0:                 } else {
aoqi@0:                     if (!ignoreErrors) {
aoqi@0:                         throw new DecodingException(
aoqi@0:                                 "UUDecoder: Missing name: " + line);
aoqi@0:                     }
aoqi@0:                 }
aoqi@0:                 gotPrefix = true;
aoqi@0:                 break;
aoqi@0:             } else if (ignoreMissingBeginEnd && line.length() != 0) {
aoqi@0:                 int count = line.charAt(0);
aoqi@0:                 count = (count - ' ') & 0x3f;
aoqi@0:                 int need = ((count * 8)+5)/6;
aoqi@0:                 if (need == 0 || line.length() >= need + 1) {
aoqi@0:                     /*
aoqi@0:                      * Looks like a legitimate encoded line.
aoqi@0:                      * Pretend we saw the "begin" line and
aoqi@0:                      * save this line for later processing in
aoqi@0:                      * decode().
aoqi@0:                      */
aoqi@0:                     readAhead = line;
aoqi@0:                     gotPrefix = true;   // fake it
aoqi@0:                     break;
aoqi@0:                 }
aoqi@0:             }
aoqi@0:         }
aoqi@0:     }
aoqi@0: 
aoqi@0:     private boolean decode() throws IOException {
aoqi@0: 
aoqi@0:         if (gotEnd) {
aoqi@0:             return false;
aoqi@0:         }
aoqi@0:         bufsize = 0;
aoqi@0:         int count = 0;
aoqi@0:         String line;
aoqi@0:         for (;;) {
aoqi@0:             /*
aoqi@0:              * If we ignored a missing "begin", the first line
aoqi@0:              * will be saved in readAhead.
aoqi@0:              */
aoqi@0:             if (readAhead != null) {
aoqi@0:                 line = readAhead;
aoqi@0:                 readAhead = null;
aoqi@0:             } else {
aoqi@0:                 line = lin.readLine();
aoqi@0:             }
aoqi@0: 
aoqi@0:             /*
aoqi@0:              * Improperly encoded data sometimes omits the zero length
aoqi@0:              * line that starts with a space character, we detect the
aoqi@0:              * following "end" line here.
aoqi@0:              */
aoqi@0:             if (line == null) {
aoqi@0:                 if (!ignoreMissingBeginEnd) {
aoqi@0:                     throw new DecodingException(
aoqi@0:                                         "UUDecoder: Missing end at EOF");
aoqi@0:                 }
aoqi@0:                 gotEnd = true;
aoqi@0:                 return false;
aoqi@0:             }
aoqi@0:             if (line.equals("end")) {
aoqi@0:                 gotEnd = true;
aoqi@0:                 return false;
aoqi@0:             }
aoqi@0:             if (line.length() == 0) {
aoqi@0:                 continue;
aoqi@0:             }
aoqi@0:             count = line.charAt(0);
aoqi@0:             if (count < ' ') {
aoqi@0:                 if (!ignoreErrors) {
aoqi@0:                     throw new DecodingException(
aoqi@0:                                         "UUDecoder: Buffer format error");
aoqi@0:                 }
aoqi@0:                 continue;
aoqi@0:             }
aoqi@0: 
aoqi@0:             /*
aoqi@0:              * The first character in a line is the number of original (not
aoqi@0:              *  the encoded atoms) characters in the line. Note that all the
aoqi@0:              *  code below has to handle the <SPACE> character that indicates
aoqi@0:              *  end of encoded stream.
aoqi@0:              */
aoqi@0:             count = (count - ' ') & 0x3f;
aoqi@0: 
aoqi@0:             if (count == 0) {
aoqi@0:                 line = lin.readLine();
aoqi@0:                 if (line == null || !line.equals("end")) {
aoqi@0:                     if (!ignoreMissingBeginEnd) {
aoqi@0:                         throw new DecodingException(
aoqi@0:                                 "UUDecoder: Missing End after count 0 line");
aoqi@0:                     }
aoqi@0:                 }
aoqi@0:                 gotEnd = true;
aoqi@0:                 return false;
aoqi@0:             }
aoqi@0: 
aoqi@0:             int need = ((count * 8)+5)/6;
aoqi@0: //System.out.println("count " + count + ", need " + need + ", len " + line.length());
aoqi@0:             if (line.length() < need + 1) {
aoqi@0:                 if (!ignoreErrors) {
aoqi@0:                     throw new DecodingException(
aoqi@0:                                         "UUDecoder: Short buffer error");
aoqi@0:                 }
aoqi@0:                 continue;
aoqi@0:             }
aoqi@0: 
aoqi@0:             // got a line we're committed to, break out and decode it
aoqi@0:             break;
aoqi@0:         }
aoqi@0: 
aoqi@0:         int i = 1;
aoqi@0:         byte a, b;
aoqi@0:         /*
aoqi@0:          * A correct uuencoder always encodes 3 characters at a time, even
aoqi@0:          * if there aren't 3 characters left.  But since some people out
aoqi@0:          * there have broken uuencoders we handle the case where they
aoqi@0:          * don't include these "unnecessary" characters.
aoqi@0:          */
aoqi@0:         while (bufsize < count) {
aoqi@0:             // continue decoding until we get 'count' decoded chars
aoqi@0:             a = (byte)((line.charAt(i++) - ' ') & 0x3f);
aoqi@0:             b = (byte)((line.charAt(i++) - ' ') & 0x3f);
aoqi@0:             buffer[bufsize++] = (byte)(((a << 2) & 0xfc) | ((b >>> 4) & 3));
aoqi@0: 
aoqi@0:             if (bufsize < count) {
aoqi@0:                 a = b;
aoqi@0:                 b = (byte)((line.charAt(i++) - ' ') & 0x3f);
aoqi@0:                 buffer[bufsize++] =
aoqi@0:                                 (byte)(((a << 4) & 0xf0) | ((b >>> 2) & 0xf));
aoqi@0:             }
aoqi@0: 
aoqi@0:             if (bufsize < count) {
aoqi@0:                 a = b;
aoqi@0:                 b = (byte)((line.charAt(i++) - ' ') & 0x3f);
aoqi@0:                 buffer[bufsize++] = (byte)(((a << 6) & 0xc0) | (b & 0x3f));
aoqi@0:             }
aoqi@0:         }
aoqi@0:         return true;
aoqi@0:     }
aoqi@0: 
aoqi@0:     /*** begin TEST program *****
aoqi@0:     public static void main(String argv[]) throws Exception {
aoqi@0:         FileInputStream infile = new FileInputStream(argv[0]);
aoqi@0:         UUDecoderStream decoder = new UUDecoderStream(infile);
aoqi@0:         int c;
aoqi@0: 
aoqi@0:         try {
aoqi@0:             while ((c = decoder.read()) != -1)
aoqi@0:                 System.out.write(c);
aoqi@0:             System.out.flush();
aoqi@0:         } catch (Exception e) {
aoqi@0:             e.printStackTrace();
aoqi@0:         }
aoqi@0:     }
aoqi@0:     **** end TEST program ****/
aoqi@0: }