org.bouncycastle.tls.ByteQueue Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of bctls-fips Show documentation
Show all versions of bctls-fips Show documentation
The Bouncy Castle Java APIs for the TLS, including a JSSE provider. The APIs are designed primarily to be used in conjunction with the BC FIPS provider. The APIs may also be used with other providers although if being used in a FIPS context it is the responsibility of the user to ensure that any other providers used are FIPS certified and used appropriately.
package org.bouncycastle.tls;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.ByteBuffer;
/**
* A queue for bytes. This file could be more optimized.
*/
public class ByteQueue
{
/**
* @return The smallest number which can be written as 2^x which is bigger than i.
*/
public static int nextTwoPow(int i)
{
/*
* This code is based of a lot of code I found on the Internet which mostly
* referenced a book called "Hacking delight".
*/
i |= (i >> 1);
i |= (i >> 2);
i |= (i >> 4);
i |= (i >> 8);
i |= (i >> 16);
return i + 1;
}
/**
* The buffer where we store our data.
*/
private byte[] databuf;
/**
* How many bytes at the beginning of the buffer are skipped.
*/
private int skipped = 0;
/**
* How many bytes in the buffer are valid data.
*/
private int available = 0;
private boolean readOnlyBuf = false;
public ByteQueue()
{
this(0);
}
public ByteQueue(int capacity)
{
databuf = capacity == 0 ? TlsUtils.EMPTY_BYTES : new byte[capacity];
}
public ByteQueue(byte[] buf, int off, int len)
{
this.databuf = buf;
this.skipped = off;
this.available = len;
this.readOnlyBuf = true;
}
/**
* Add some data to our buffer.
*
* @param buf A byte-array to read data from.
* @param off How many bytes to skip at the beginning of the array.
* @param len How many bytes to read from the array.
*/
public void addData(byte[] buf, int off, int len)
{
if (readOnlyBuf)
{
throw new IllegalStateException("Cannot add data to read-only buffer");
}
if (available == 0)
{
if (len > databuf.length)
{
int desiredSize = nextTwoPow(len | 256);
databuf = new byte[desiredSize];
}
skipped = 0;
}
else if ((skipped + available + len) > databuf.length)
{
int desiredSize = nextTwoPow(available + len);
if (desiredSize > databuf.length)
{
byte[] tmp = new byte[desiredSize];
System.arraycopy(databuf, skipped, tmp, 0, available);
databuf = tmp;
}
else
{
System.arraycopy(databuf, skipped, databuf, 0, available);
}
skipped = 0;
}
System.arraycopy(buf, off, databuf, skipped + available, len);
available += len;
}
/**
* @return The number of bytes which are available in this buffer.
*/
public int available()
{
return available;
}
/**
* Copy some bytes from the beginning of the data to the provided {@link OutputStream}.
*
* @param output The {@link OutputStream} to copy the bytes to.
* @param length How many bytes to copy.
*/
public void copyTo(OutputStream output, int length) throws IOException
{
if (length > available)
{
throw new IllegalStateException("Cannot copy " + length + " bytes, only got " + available);
}
output.write(databuf, skipped, length);
}
/**
* Read data from the buffer.
*
* @param buf The buffer where the read data will be copied to.
* @param offset How many bytes to skip at the beginning of buf.
* @param len How many bytes to read at all.
* @param skip How many bytes from our data to skip.
*/
public void read(byte[] buf, int offset, int len, int skip)
{
if ((buf.length - offset) < len)
{
throw new IllegalArgumentException("Buffer size of " + buf.length
+ " is too small for a read of " + len + " bytes");
}
if ((available - skip) < len)
{
throw new IllegalStateException("Not enough data to read");
}
System.arraycopy(databuf, skipped + skip, buf, offset, len);
}
/**
* Read data from the buffer.
*
* @param buf The {@link ByteBuffer} where the read data will be copied to.
* @param len How many bytes to read at all.
* @param skip How many bytes from our data to skip.
*/
public void read(ByteBuffer buf, int len, int skip)
{
int remaining = buf.remaining();
if (remaining < len)
{
throw new IllegalArgumentException(
"Buffer size of " + remaining + " is too small for a read of " + len + " bytes");
}
if ((available - skip) < len)
{
throw new IllegalStateException("Not enough data to read");
}
buf.put(databuf, skipped + skip, len);
}
/**
* Return a {@link HandshakeMessageInput} over some bytes at the beginning of the data.
*
* @param length
* How many bytes will be readable.
* @return A {@link HandshakeMessageInput} over the data.
*/
HandshakeMessageInput readHandshakeMessage(int length)
{
if (length > available)
{
throw new IllegalStateException("Cannot read " + length + " bytes, only got " + available);
}
int position = skipped;
available -= length;
skipped += length;
return new HandshakeMessageInput(databuf, position, length);
}
public int readInt32()
{
if (available < 4)
{
throw new IllegalStateException("Not enough data to read");
}
return TlsUtils.readInt32(databuf, skipped);
}
public short readUint8(int skip)
{
if (available < skip + 1)
{
throw new IllegalStateException("Not enough data to read");
}
return TlsUtils.readUint8(databuf, skipped + skip);
}
public int readUint16(int skip)
{
if (available < skip + 2)
{
throw new IllegalStateException("Not enough data to read");
}
return TlsUtils.readUint16(databuf, skipped + skip);
}
/**
* Remove some bytes from our data from the beginning.
*
* @param i How many bytes to remove.
*/
public void removeData(int i)
{
if (i > available)
{
throw new IllegalStateException("Cannot remove " + i + " bytes, only got " + available);
}
/*
* Skip the data.
*/
available -= i;
skipped += i;
}
/**
* Remove data from the buffer.
*
* @param buf The buffer where the removed data will be copied to.
* @param off How many bytes to skip at the beginning of buf.
* @param len How many bytes to read at all.
* @param skip How many bytes from our data to skip.
*/
public void removeData(byte[] buf, int off, int len, int skip)
{
read(buf, off, len, skip);
removeData(skip + len);
}
/**
* Remove data from the buffer.
*
* @param buf The {@link ByteBuffer} where the removed data will be copied to.
* @param len How many bytes to read at all.
* @param skip How many bytes from our data to skip.
*/
public void removeData(ByteBuffer buf, int len, int skip)
{
read(buf, len, skip);
removeData(skip + len);
}
public byte[] removeData(int len, int skip)
{
byte[] buf = new byte[len];
removeData(buf, 0, len, skip);
return buf;
}
public void shrink()
{
if (available == 0)
{
databuf = TlsUtils.EMPTY_BYTES;
skipped = 0;
}
else
{
int desiredSize = nextTwoPow(available);
if (desiredSize < databuf.length)
{
byte[] tmp = new byte[desiredSize];
System.arraycopy(databuf, skipped, tmp, 0, available);
databuf = tmp;
skipped = 0;
}
}
}
}
© 2015 - 2024 Weber Informatics LLC | Privacy Policy