* The data elements this class caters for are described in [1]. *
* References: *
* Calls the method with the same name and three arguments as:
* getInstance(raw, 0, raw.length).
*
* @param raw the encoded form, excluding the header bytes, of a SASL buffer.
* @return a new instance of {@link InputBuffer}.
*/
public static InputBuffer getInstance(byte[] raw)
{
return getInstance(raw, 0, raw.length);
}
/**
* Returns an instance of a SASL buffer given the buffer's encoded contents,
* excluding the buffer's header bytes.
*
* @param raw the encoded form, excluding the header bytes, of a SASL buffer.
* @param offset offset where to start using raw bytes from.
* @param len number of bytes to use.
* @return a new instance of {@link InputBuffer}.
*/
public static InputBuffer getInstance(byte[] raw, int offset, int len)
{
InputBuffer result = new InputBuffer();
result.in = new ByteArrayInputStream(raw, offset, len);
return result;
}
/**
* Converts two octets into the number that they represent.
*
* @param b the two octets.
* @return the length.
*/
public static int twoBytesToLength(byte[] b) throws SaslEncodingException
{
final int result = (b[0] & 0xFF) << 8 | (b[1] & 0xFF);
if (result > Registry.SASL_TWO_BYTE_MAX_LIMIT)
throw new SaslEncodingException("SASL MPI/Text size limit exceeded");
return result;
}
public boolean hasMoreElements()
{
return (in.available() > 0);
}
/**
* Decodes a SASL scalar quantity, count-octet long, from the
* current buffer.
*
* @param count the number of octets of this scalar quantity.
* @return a native representation of a SASL scalar (unsigned integer)
* quantity.
* @throws SaslEncodingException if an encoding exception occurs during the
* operation.
* @throws IOException if any other I/O exception occurs during the operation.
*/
public long getScalar(int count) throws IOException
{
if (count < 0 || count > 4)
throw new SaslEncodingException("Invalid SASL scalar octet count: "
+ String.valueOf(count));
if (! hasMoreElements())
throw new SaslEncodingException("Not enough bytes for a scalar in buffer");
if (in.available() < count)
throw new SaslEncodingException("Illegal SASL scalar encoding");
byte[] element = new byte[count];
in.read(element);
long result = 0L;
for (int i = 0; i < count; i++)
{
result <<= 8;
result |= element[i] & 0xFFL;
}
return result;
}
/**
* Decodes a SASL OS from the current buffer.
*
* @return a native representation of a SASL OS.
* @throws SaslEncodingException if an encoding exception occurs during the
* operation.
* @throws IOException if any other I/O exception occurs during the operation.
*/
public byte[] getOS() throws IOException
{
if (! hasMoreElements())
throw new SaslEncodingException(
"Not enough bytes for an octet-sequence in buffer");
final int elementLength = in.read();
if (elementLength > Registry.SASL_ONE_BYTE_MAX_LIMIT)
throw new SaslEncodingException("SASL octet-sequence size limit exceeded");
if (in.available() < elementLength)
throw new SaslEncodingException("Illegal SASL octet-sequence encoding");
byte[] result = new byte[elementLength];
in.read(result);
return result;
}
/**
* Decodes a SASL EOS from the current buffer.
*
* @return a native representation of a SASL EOS.
* @throws SaslEncodingException if an encoding exception occurs during the
* operation.
* @throws IOException if any other I/O exception occurs during the operation.
*/
public byte[] getEOS() throws IOException
{
if (in.available() < 2)
throw new SaslEncodingException(
"Not enough bytes for an extended octet-sequence in buffer");
byte[] elementLengthBytes = new byte[2];
in.read(elementLengthBytes);
final int elementLength = twoBytesToLength(elementLengthBytes);
if (in.available() < elementLength)
throw new SaslEncodingException(
"Illegal SASL extended octet-sequence encoding");
byte[] result = new byte[elementLength];
in.read(result);
return result;
}
/**
* Decodes a SASL MPI from the current buffer.
*
* @return a native representation of a SASL MPI.
* @throws SaslEncodingException if an encoding exception occurs during the
* operation.
* @throws IOException if any other I/O exception occurs during the operation.
*/
public BigInteger getMPI() throws IOException
{
if (in.available() < 2)
throw new SaslEncodingException("Not enough bytes for an MPI in buffer");
byte[] elementLengthBytes = new byte[2];
in.read(elementLengthBytes);
final int elementLength = twoBytesToLength(elementLengthBytes);
if (in.available() < elementLength)
throw new SaslEncodingException(
"Illegal SASL multi-precision integer encoding");
byte[] element = new byte[elementLength];
in.read(element);
return new BigInteger(1, element);
}
/**
* Decodes a SASL Text from the current buffer.
*
* @return a native representation of a SASL Text.
* @throws SaslEncodingException if an encoding exception occurs during the
* operation.
* @throws SaslEncodingException if the UTF-8 character encoding is not
* supported on this platform.
* @throws IOException if any other I/O exception occurs during the operation.
*/
public String getText() throws IOException
{
if (in.available() < 2)
throw new SaslEncodingException("Not enough bytes for a text in buffer");
byte[] elementLengthBytes = new byte[2];
in.read(elementLengthBytes);
final int elementLength = twoBytesToLength(elementLengthBytes);
if (in.available() < elementLength)
throw new SaslEncodingException("Illegal SASL text encoding");
byte[] element = new byte[elementLength];
in.read(element);
return new String(element, "UTF8");
}
}