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API common to all crypto modules
/*
* See the NOTICE file distributed with this work for additional
* information regarding copyright ownership.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.xwiki.crypto.internal.encoder;
import java.io.ByteArrayOutputStream;
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
/**
* An input stream wrapper that will decode string data to binary in block.
*
* @version $Id: 7e14cc3b12f7bfc6f644f063b76859056e0a92ce $
* @since 5.4M1
*/
class BcBinaryStringEncoderInputStream extends FilterInputStream
{
/** Number of bytes of binary data that is produced from {@code charSize} chars of encoded data. */
private final int blockSize;
/** Number of bytes of string data that should be decoded together. */
private final int charSize;
/** A one byte buffer to optimize one byte writing. */
private byte[] oneByte = new byte[1];
/** An overflow buffer to collate data read in advance. */
private byte[] ofBuf;
/** Current offset in byte of valid data in the overflow buffer. */
private int ofOff;
/** Current length in byte of valid data in the overflow buffer. */
private int ofLen;
/** Encoder used to decode data. */
private final InternalBinaryStringEncoder encoder;
/**
* Buffer reading input data for a given number of input blocks (including blanks).
*/
class InputBuffer
{
/** Buffer to containing read data. */
private byte[] buf;
/** Length in bytes of valid data in the buffer. */
private int bufLen;
/** Count in bytes of blanks chars in the buffer. */
private int bcount;
/** Count in bytes of blanks chars read during the last read operation. */
private int rblank;
/**
* Construct an new buffer initialized with the amount of data requested, or less if EOF is reach.
*
* @param blen number of block of input string data to read.
* @throws IOException on error.
*/
InputBuffer(int blen) throws IOException
{
int rlen = 0;
int rbl = blen * BcBinaryStringEncoderInputStream.this.charSize;
this.buf = new byte[rbl];
// Try to read the number of block requested, read more as needed if some blank char has been read.
while (rbl > 0 && rlen >= 0) {
rlen = read(rbl);
rbl = this.rblank;
}
rlen = this.bufLen - this.bcount;
// Some non-blank data found ?
if (rlen > 0) {
// Wait until reaching EOF or being aligned on block size
// Remember that some input stream may be lazy,
// but should at least return one byte, else EOF is reached.
int rblen = (rlen + BcBinaryStringEncoderInputStream.this.charSize - 1)
/ BcBinaryStringEncoderInputStream.this.charSize;
int runder = (rblen * BcBinaryStringEncoderInputStream.this.charSize) - rlen;
int rrlen = 0;
while (runder > 0 && rrlen >= 0) {
rrlen = read(runder);
if (rrlen > 0) {
runder -= rrlen - this.rblank;
}
}
}
}
/**
* @return the data buffer.
*/
byte[] getBuffer()
{
return this.buf;
}
/**
* @return the length in bytes of valid data in the buffer.
*/
int getReadLength()
{
return this.bufLen;
}
/**
* @return the count in bytes of non-blank data in the buffer.
*/
int getEffectiveLength()
{
return this.bufLen - this.bcount;
}
/**
* Count blanks char in a given area of the buffer.
*
* @param off starting offset
* @param len length of the area
* @return number of bytes containing blank characters.
*/
private int countBlank(int off, int len)
{
int blank = 0;
for (int i = off; i < len; i++) {
if (isBlank(this.buf[i])) {
blank++;
}
}
return blank;
}
private boolean isBlank(byte b)
{
return (b == '\n' || b == '\r' || b == '\t' || b == ' ');
}
/**
* Ensure the buffer is large enough to contains a given amount of bytes.
*
* @param len the number of bytes the buffer should be able to contains.
*/
private void ensureSize(int len)
{
if (len > this.buf.length) {
byte[] nbuf = new byte[len];
System.arraycopy(this.buf, 0, nbuf, 0, this.buf.length);
this.buf = nbuf;
}
}
/**
* Appends some data from the input stream to valid data in the buffer.
*
* @param len number of bytes to be read.
* @return number of bytes effectively read.
* @throws IOException on error.
*/
private int read(int len) throws IOException
{
ensureSize(this.bufLen + len);
return readBase64(len);
}
/**
* Append only valid base64 data from the input stream in the buffer.
*
* The buffer may be affected over len size even if the returned len is lower.
*
* @param len number of bytes to be read.
* @return number of bytes effectively read.
* @throws IOException on error.
*/
private int readBase64(int len) throws IOException
{
int rlen;
if (BcBinaryStringEncoderInputStream.this.in.markSupported()) {
rlen = readBase64WithMark(len);
} else {
rlen = readBase64WithoutMark(len);
}
if (rlen > 0) {
this.rblank = countBlank(this.bufLen, rlen);
this.bufLen += rlen;
this.bcount += this.rblank;
return rlen;
}
return -1;
}
private int readBase64WithoutMark(int len) throws IOException
{
int rlen;
rlen = this.bufLen;
while (rlen < (this.bufLen + len)) {
int c = BcBinaryStringEncoderInputStream.this.in.read();
if (c < 0) {
break;
}
byte b = (byte) c;
if (!isBlank(b) && !BcBinaryStringEncoderInputStream.this.encoder.isValidEncoding(b)) {
break;
}
this.buf[rlen++] = b;
}
rlen -= this.bufLen;
return rlen;
}
private int readBase64WithMark(int len) throws IOException
{
int rlen;
BcBinaryStringEncoderInputStream.this.in.mark(len);
rlen = BcBinaryStringEncoderInputStream.this.in.read(this.buf, this.bufLen, len);
int i = this.bufLen;
while (i < (this.bufLen + rlen)) {
byte b = this.buf[i];
if (!isBlank(b) && !BcBinaryStringEncoderInputStream.this.encoder.isValidEncoding(b)) {
break;
}
i++;
}
i -= this.bufLen;
if (i < rlen) {
BcBinaryStringEncoderInputStream.this.in.reset();
rlen = (int) BcBinaryStringEncoderInputStream.this.in.skip(i);
}
return rlen;
}
}
/**
* Construct a filter stream for the given encoder, following the specifications.
*
* @param inputStream the underlying input stream where data will be read.
* @param encoder the encoder used to decode data.
*/
BcBinaryStringEncoderInputStream(InputStream inputStream, InternalBinaryStringEncoder encoder)
{
super(inputStream);
this.encoder = encoder;
this.blockSize = encoder.getEncodingBlockSize();
this.charSize = encoder.getDecodingBlockSize();
this.ofBuf = new byte[this.blockSize];
}
@Override
public int read() throws IOException
{
if (read(this.oneByte, 0, 1) > 0) {
return this.oneByte[0];
}
return -1;
}
@Override
public int read(byte[] out, int offset, int length) throws IOException
{
if ((offset | length | (out.length - (length + offset)) | (offset + length)) < 0) {
throw new IndexOutOfBoundsException();
}
if (length == 0) {
return 0;
}
int readLen = 0;
int off = offset;
int len = length;
// Is some pending data of a previous call available ?
if (this.ofLen > 0) {
int clen = copyData(this.ofBuf, this.ofOff, this.ofLen, out, off, len);
this.ofLen -= clen;
this.ofOff += clen;
off += clen;
len -= clen;
readLen += clen;
}
// Still some data to read ?
if (len > 0) {
// Try to read the needed block to get -len- bytes decoded
int blen = (len + this.blockSize - 1) / this.blockSize;
InputBuffer inBuf = new InputBuffer(blen);
int rlen = inBuf.getEffectiveLength();
if (rlen > 0) {
int rblen = (rlen + this.charSize - 1) / this.charSize;
// Decode read data
ByteArrayOutputStream baos = new ByteArrayOutputStream(rblen * this.blockSize);
this.encoder.decode(inBuf.getBuffer(), 0, inBuf.getReadLength(), baos);
baos.close();
int clen = copyData(baos.toByteArray(), 0, baos.size(), out, off, len);
readLen += clen;
this.ofLen = baos.size() - clen;
this.ofOff = 0;
if (this.ofLen > 0) {
System.arraycopy(baos.toByteArray(), clen, this.ofBuf, this.ofOff, this.ofLen);
}
}
}
return (readLen > 0) ? readLen : -1;
}
@Override
public int available() throws IOException
{
int len = super.available();
return ((len + this.charSize - 1) / this.charSize) * this.blockSize;
}
@Override
public boolean markSupported()
{
return false;
}
private int copyData(byte[] inBuf, int inOff, int inLen, byte[] outBuf, int outOff, int outLen)
{
int clen = inLen;
if (clen > outLen) {
clen = outLen;
}
System.arraycopy(inBuf, inOff, outBuf, outOff, clen);
return clen;
}
}
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