/* * Copyright (c) 1995, 2000, 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. */package sun.misc; import java.io.OutputStream;import java.io.ByteArrayOutputStream;import java.io.PushbackInputStream;import java.io.PrintStream;import java.io.IOException; /** * This class implements a robust character decoder. The decoder will * converted encoded text into binary data. * * The basic encoding unit is a 3 character atom. It encodes two bytes * of data. Bytes are encoded into a 64 character set, the characters * were chosen specifically because they appear in all codesets. * We don't care what their numerical equivalent is because * we use a character array to map them. This is like UUencoding * with the dependency on ASCII removed. * * The three chars that make up an atom are encoded as follows: * <pre> * 00xxxyyy 00axxxxx 00byyyyy * 00 = leading zeros, all values are 0 - 63 * xxxyyy - Top 3 bits of X, Top 3 bits of Y * axxxxx - a = X parity bit, xxxxx lower 5 bits of X * byyyyy - b = Y parity bit, yyyyy lower 5 bits of Y * </pre> * * The atoms are arranged into lines suitable for inclusion into an * email message or text file. The number of bytes that are encoded * per line is 48 which keeps the total line length under 80 chars) * * Each line has the form( * <pre> * *(LLSS)(DDDD)(DDDD)(DDDD)...(CRC) * Where each (xxx) represents a three character atom. * (LLSS) - 8 bit length (high byte), and sequence number * modulo 256; * (DDDD) - Data byte atoms, if length is odd, last data * atom has (DD00) (high byte data, low byte 0) * (CRC) - 16 bit CRC for the line, includes length, * sequence, and all data bytes. If there is a * zero pad byte (odd length) it is _NOT_ * included in the CRC. * </pre> * * If an error is encountered during decoding this class throws a * CEFormatException. The specific detail messages are: * * <pre> * "UCDecoder: High byte parity error." * "UCDecoder: Low byte parity error." * "UCDecoder: Out of sequence line." * "UCDecoder: CRC check failed." * </pre> * * @author Chuck McManis * @see CharacterEncoder * @see UCEncoder */public class UCDecoder extends CharacterDecoder { /** This class encodes two bytes per atom. */ protected int bytesPerAtom() { return (2); } /** this class encodes 48 bytes per line */ protected int bytesPerLine() { return (48); } /* this is the UCE mapping of 0-63 to characters .. */ private final static byte map_array[] = { // 0 1 2 3 4 5 6 7 (byte)'0',(byte)'1',(byte)'2',(byte)'3',(byte)'4',(byte)'5',(byte)'6',(byte)'7', // 0 (byte)'8',(byte)'9',(byte)'A',(byte)'B',(byte)'C',(byte)'D',(byte)'E',(byte)'F', // 1 (byte)'G',(byte)'H',(byte)'I',(byte)'J',(byte)'K',(byte)'L',(byte)'M',(byte)'N', // 2 (byte)'O',(byte)'P',(byte)'Q',(byte)'R',(byte)'S',(byte)'T',(byte)'U',(byte)'V', // 3 (byte)'W',(byte)'X',(byte)'Y',(byte)'Z',(byte)'a',(byte)'b',(byte)'c',(byte)'d', // 4 (byte)'e',(byte)'f',(byte)'g',(byte)'h',(byte)'i',(byte)'j',(byte)'k',(byte)'l', // 5 (byte)'m',(byte)'n',(byte)'o',(byte)'p',(byte)'q',(byte)'r',(byte)'s',(byte)'t', // 6 (byte)'u',(byte)'v',(byte)'w',(byte)'x',(byte)'y',(byte)'z',(byte)'(',(byte)')' // 7 }; private int sequence; private byte tmp[] = new byte[2]; private CRC16 crc = new CRC16(); /** * Decode one atom - reads the characters from the input stream, decodes * them, and checks for valid parity. */ protected void decodeAtom(PushbackInputStream inStream, OutputStream outStream, int l) throws IOException { int i, p1, p2, np1, np2; byte a = -1, b = -1, c = -1; byte high_byte, low_byte; byte tmp[] = new byte[3]; i = inStream.read(tmp); if (i != 3) { throw new CEStreamExhausted(); } for (i = 0; (i < 64) && ((a == -1) || (b == -1) || (c == -1)); i++) { if (tmp[0] == map_array[i]) { a = (byte) i; } if (tmp[1] == map_array[i]) { b = (byte) i; } if (tmp[2] == map_array[i]) { c = (byte) i; } } high_byte = (byte) (((a & 0x38) << 2) + (b & 0x1f)); low_byte = (byte) (((a & 0x7) << 5) + (c & 0x1f)); p1 = 0; p2 = 0; for (i = 1; i < 256; i = i * 2) { if ((high_byte & i) != 0) p1++; if ((low_byte & i) != 0) p2++; } np1 = (b & 32) / 32; np2 = (c & 32) / 32; if ((p1 & 1) != np1) { throw new CEFormatException("UCDecoder: High byte parity error."); } if ((p2 & 1) != np2) { throw new CEFormatException("UCDecoder: Low byte parity error."); } outStream.write(high_byte); crc.update(high_byte); if (l == 2) { outStream.write(low_byte); crc.update(low_byte); } } private ByteArrayOutputStream lineAndSeq = new ByteArrayOutputStream(2); /** * decodeBufferPrefix initializes the sequence number to zero. */ protected void decodeBufferPrefix(PushbackInputStream inStream, OutputStream outStream) { sequence = 0; } /** * decodeLinePrefix reads the sequence number and the number of * encoded bytes from the line. If the sequence number is not the * previous sequence number + 1 then an exception is thrown. * UCE lines are line terminator immune, they all start with * * so the other thing this method does is scan for the next line * by looking for the * character. * * @exception CEFormatException out of sequence lines detected. */ protected int decodeLinePrefix(PushbackInputStream inStream, OutputStream outStream) throws IOException { int i; int nLen, nSeq; byte xtmp[]; int c; crc.value = 0; while (true) { c = inStream.read(tmp, 0, 1); if (c == -1) { throw new CEStreamExhausted(); } if (tmp[0] == '*') { break; } } lineAndSeq.reset(); decodeAtom(inStream, lineAndSeq, 2); xtmp = lineAndSeq.toByteArray(); nLen = xtmp[0] & 0xff; nSeq = xtmp[1] & 0xff; if (nSeq != sequence) { throw new CEFormatException("UCDecoder: Out of sequence line."); } sequence = (sequence + 1) & 0xff; return (nLen); } /** * this method reads the CRC that is at the end of every line and * verifies that it matches the computed CRC. * * @exception CEFormatException if CRC check fails. */ protected void decodeLineSuffix(PushbackInputStream inStream, OutputStream outStream) throws IOException { int i; int lineCRC = crc.value; int readCRC; byte tmp[]; lineAndSeq.reset(); decodeAtom(inStream, lineAndSeq, 2); tmp = lineAndSeq.toByteArray(); readCRC = ((tmp[0] << 8) & 0xFF00) + (tmp[1] & 0xff); if (readCRC != lineCRC) { throw new CEFormatException("UCDecoder: CRC check failed."); } }}
/*
* Copyright (c) 1995, 2000, 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.
*/
package sun.misc;
import java.io.OutputStream;
import java.io.ByteArrayOutputStream;
import java.io.PushbackInputStream;
import java.io.PrintStream;
import java.io.IOException;
/**
* This class implements a robust character decoder. The decoder will
* converted encoded text into binary data.
*
* The basic encoding unit is a 3 character atom. It encodes two bytes
* of data. Bytes are encoded into a 64 character set, the characters
* were chosen specifically because they appear in all codesets.
* We don't care what their numerical equivalent is because
* we use a character array to map them. This is like UUencoding
* with the dependency on ASCII removed.
*
* The three chars that make up an atom are encoded as follows:
* <pre>
* 00xxxyyy 00axxxxx 00byyyyy
* 00 = leading zeros, all values are 0 - 63
* xxxyyy - Top 3 bits of X, Top 3 bits of Y
* axxxxx - a = X parity bit, xxxxx lower 5 bits of X
* byyyyy - b = Y parity bit, yyyyy lower 5 bits of Y
* </pre>
*
* The atoms are arranged into lines suitable for inclusion into an
* email message or text file. The number of bytes that are encoded
* per line is 48 which keeps the total line length under 80 chars)
*
* Each line has the form(
* <pre>
* *(LLSS)(DDDD)(DDDD)(DDDD)...(CRC)
* Where each (xxx) represents a three character atom.
* (LLSS) - 8 bit length (high byte), and sequence number
* modulo 256;
* (DDDD) - Data byte atoms, if length is odd, last data
* atom has (DD00) (high byte data, low byte 0)
* (CRC) - 16 bit CRC for the line, includes length,
* sequence, and all data bytes. If there is a
* zero pad byte (odd length) it is _NOT_
* included in the CRC.
* </pre>
*
* If an error is encountered during decoding this class throws a
* CEFormatException. The specific detail messages are:
*
* <pre>
* "UCDecoder: High byte parity error."
* "UCDecoder: Low byte parity error."
* "UCDecoder: Out of sequence line."
* "UCDecoder: CRC check failed."
* </pre>
*
* @author Chuck McManis
* @see CharacterEncoder
* @see UCEncoder
*/
public class UCDecoder extends CharacterDecoder {
/** This class encodes two bytes per atom. */
protected int bytesPerAtom() {
return (2);
}
/** this class encodes 48 bytes per line */
protected int bytesPerLine() {
return (48);
}
/* this is the UCE mapping of 0-63 to characters .. */
private final static byte map_array[] = {
// 0 1 2 3 4 5 6 7
(byte)'0',(byte)'1',(byte)'2',(byte)'3',(byte)'4',(byte)'5',(byte)'6',(byte)'7', // 0
(byte)'8',(byte)'9',(byte)'A',(byte)'B',(byte)'C',(byte)'D',(byte)'E',(byte)'F', // 1
(byte)'G',(byte)'H',(byte)'I',(byte)'J',(byte)'K',(byte)'L',(byte)'M',(byte)'N', // 2
(byte)'O',(byte)'P',(byte)'Q',(byte)'R',(byte)'S',(byte)'T',(byte)'U',(byte)'V', // 3
(byte)'W',(byte)'X',(byte)'Y',(byte)'Z',(byte)'a',(byte)'b',(byte)'c',(byte)'d', // 4
(byte)'e',(byte)'f',(byte)'g',(byte)'h',(byte)'i',(byte)'j',(byte)'k',(byte)'l', // 5
(byte)'m',(byte)'n',(byte)'o',(byte)'p',(byte)'q',(byte)'r',(byte)'s',(byte)'t', // 6
(byte)'u',(byte)'v',(byte)'w',(byte)'x',(byte)'y',(byte)'z',(byte)'(',(byte)')' // 7
};
private int sequence;
private byte tmp[] = new byte[2];
private CRC16 crc = new CRC16();
/**
* Decode one atom - reads the characters from the input stream, decodes
* them, and checks for valid parity.
*/
protected void decodeAtom(PushbackInputStream inStream, OutputStream outStream, int l) throws IOException {
int i, p1, p2, np1, np2;
byte a = -1, b = -1, c = -1;
byte high_byte, low_byte;
byte tmp[] = new byte[3];
i = inStream.read(tmp);
if (i != 3) {
throw new CEStreamExhausted();
}
for (i = 0; (i < 64) && ((a == -1) || (b == -1) || (c == -1)); i++) {
if (tmp[0] == map_array[i]) {
a = (byte) i;
}
if (tmp[1] == map_array[i]) {
b = (byte) i;
}
if (tmp[2] == map_array[i]) {
c = (byte) i;
}
}
high_byte = (byte) (((a & 0x38) << 2) + (b & 0x1f));
low_byte = (byte) (((a & 0x7) << 5) + (c & 0x1f));
p1 = 0;
p2 = 0;
for (i = 1; i < 256; i = i * 2) {
if ((high_byte & i) != 0)
p1++;
if ((low_byte & i) != 0)
p2++;
}
np1 = (b & 32) / 32;
np2 = (c & 32) / 32;
if ((p1 & 1) != np1) {
throw new CEFormatException("UCDecoder: High byte parity error.");
}
if ((p2 & 1) != np2) {
throw new CEFormatException("UCDecoder: Low byte parity error.");
}
outStream.write(high_byte);
crc.update(high_byte);
if (l == 2) {
outStream.write(low_byte);
crc.update(low_byte);
}
}
private ByteArrayOutputStream lineAndSeq = new ByteArrayOutputStream(2);
/**
* decodeBufferPrefix initializes the sequence number to zero.
*/
protected void decodeBufferPrefix(PushbackInputStream inStream, OutputStream outStream) {
sequence = 0;
}
/**
* decodeLinePrefix reads the sequence number and the number of
* encoded bytes from the line. If the sequence number is not the
* previous sequence number + 1 then an exception is thrown.
* UCE lines are line terminator immune, they all start with *
* so the other thing this method does is scan for the next line
* by looking for the * character.
*
* @exception CEFormatException out of sequence lines detected.
*/
protected int decodeLinePrefix(PushbackInputStream inStream, OutputStream outStream) throws IOException {
int i;
int nLen, nSeq;
byte xtmp[];
int c;
crc.value = 0;
while (true) {
c = inStream.read(tmp, 0, 1);
if (c == -1) {
throw new CEStreamExhausted();
}
if (tmp[0] == '*') {
break;
}
}
lineAndSeq.reset();
decodeAtom(inStream, lineAndSeq, 2);
xtmp = lineAndSeq.toByteArray();
nLen = xtmp[0] & 0xff;
nSeq = xtmp[1] & 0xff;
if (nSeq != sequence) {
throw new CEFormatException("UCDecoder: Out of sequence line.");
}
sequence = (sequence + 1) & 0xff;
return (nLen);
}
/**
* this method reads the CRC that is at the end of every line and
* verifies that it matches the computed CRC.
*
* @exception CEFormatException if CRC check fails.
*/
protected void decodeLineSuffix(PushbackInputStream inStream, OutputStream outStream) throws IOException {
int i;
int lineCRC = crc.value;
int readCRC;
byte tmp[];
lineAndSeq.reset();
decodeAtom(inStream, lineAndSeq, 2);
tmp = lineAndSeq.toByteArray();
readCRC = ((tmp[0] << 8) & 0xFF00) + (tmp[1] & 0xff);
if (readCRC != lineCRC) {
throw new CEFormatException("UCDecoder: CRC check failed.");
}
}
}