com.entrust.toolkit.util

Class ByteStreamSerializer

java.lang.Object

com.entrust.toolkit.util.ByteStreamSerializer

public class ByteStreamSerializer
extends java.lang.Object

The ByteStreamSerializer is useful for serializing/deserializing byte stream data in a format that is compliant to the TLS 1.2 specification. It is also used for the Data Specification of Certificate Transparency (RFC 6962).

Field Summary

Fields

Modifier and Type	Field and Description
static int	MAXREADLIMIT This is the largest data size allowed for certificate transparency, so CAP reading input at this size (by default).

Constructor Summary

Constructors

Constructor and Description
ByteStreamSerializer()

Method Summary

Methods

Modifier and Type	Method and Description
static int	calculateByteLength(long datalen) This helper function calculates the number of bytes required to store the length of the given data.
static byte[]	readDefiniteLength(java.io.InputStream is, int datalen) Reads datalen number of bytes from the specified input Stream.
static byte[]	readDefiniteLengthFromStream(java.io.InputStream is, int datalen, int limit) Read a fixed number of bytes from the specified input stream, but do not allow more than limit to be read.
static byte[]	readIndefiniteLength(java.io.InputStream is, int maxBytes) This function will read indefinite length data.
static byte[]	readIndefiniteLength(java.io.InputStream is, int maxBytes, int readLimit) This function will read indefinite length data.
static long	readLongValue(java.io.InputStream is, int bytes) Reads the specified number of bytes and returns them as a Long value.
static void	writeDefiniteLength(java.io.OutputStream os, byte[] data) Writes a pre-defined number of bytes to the specified output stream.
static void	writeIndefiniteLength(java.io.OutputStream os, byte[] data, int maxByteLength) Write the specified data of indefinite length to the given OutputStream.
static void	writeLongValue(java.io.OutputStream os, long value) Writes the specified Long value to the given OutputStream
static void	writeLongValue(java.io.OutputStream os, long value, int bytes) Write the specified long value to the given OutputStream by converting the long value to a stream of bytes where the most significant bit is first.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

MAXREADLIMIT

public static final int MAXREADLIMIT

This is the largest data size allowed for certificate transparency, so CAP reading input at this size (by default).

See Also:

Constant Field Values

Constructor Detail

ByteStreamSerializer

public ByteStreamSerializer()

Method Detail

readDefiniteLength

public static byte[] readDefiniteLength(java.io.InputStream is,
                        int datalen)
                                 throws java.io.IOException

Reads datalen number of bytes from the specified input Stream.

Parameters:

is - The InputStream to read the data

datalen - the number of bytes to read from the inputStream.

Returns:

The bytes read from the stream

Throws:

java.io.IOException - if error reading data, or data is too large

readDefiniteLengthFromStream

public static byte[] readDefiniteLengthFromStream(java.io.InputStream is,
                                  int datalen,
                                  int limit)
                                           throws java.io.IOException

Read a fixed number of bytes from the specified input stream, but do not allow more than limit to be read. We don't want to cause an OutOfMemoryException.

Parameters:

is - The InputStream to read data

datalen - The length of the definite length data to be read

limit - the limit on the size of the data

Returns:

the byte array representing the data

Throws:

java.io.IOException - if error reading data, or data is too large

readLongValue

public static long readLongValue(java.io.InputStream is,
                 int bytes)
                          throws java.io.IOException

Reads the specified number of bytes and returns them as a Long value. Since a long is a 64-bit value, no more than 8 bytes can be read by this function

Parameters:

is - The input stream for the data to be read

bytes - the number of bytes that will be used to compute the long value

Returns:

a number of at most 2^64 (a 64-bit long value)

Throws:

java.io.IOException - if error reading InputStream, or bytes is negative or greater than 8.

readIndefiniteLength

public static byte[] readIndefiniteLength(java.io.InputStream is,
                          int maxBytes)
                                   throws java.io.IOException

This function will read indefinite length data. The function first reads the length of the data from the given inputStream as a long value, and then reads the result of the data as definite length from the stream. This function will cap the data being read at MAXREADLIMIT

Parameters:

is - the inputstream used to read the data

maxBytes - the maximum size of the data length (used to read the length of the data)

Returns:

The byte array containing the data

Throws:

java.io.IOException - if an error occurs when reading the data

readIndefiniteLength

public static byte[] readIndefiniteLength(java.io.InputStream is,
                          int maxBytes,
                          int readLimit)
                                   throws java.io.IOException

This function will read indefinite length data. The function first reads the length of the data from the given inputStream as a long value, and then reads the result of the data as a definite length from the stream. This function will CAP the data being read at readLimit

Note: The maxBytes parameter is required so that the number of bytes required can be read. To know how many bytes need to be read, the maximum data length needs to be known so that the correct length can be read.

Parameters:

is - the inputstream used to read the data

maxBytes - the maximum size of the data length

readLimit - The absolute maximum data this function will allow to be read

Returns:

The byte array containing the data

Throws:

java.io.IOException - if an error occurs when reading the data

calculateByteLength

public static int calculateByteLength(long datalen)

This helper function calculates the number of bytes required to store the length of the given data. This is needed when encoding the data to an outputStream. The largest value that can be returned from this function is 8 because a long in Java is 64 bits.

Parameters:

datalen - the length of the data as an integer

Returns:

byte length required to store the specified data length

writeLongValue

public static void writeLongValue(java.io.OutputStream os,
                  long value,
                  int bytes)
                           throws java.io.IOException

Write the specified long value to the given OutputStream by converting the long value to a stream of bytes where the most significant bit is first.

Note: The numbers of bytes must be in the range 0 to 8.

Parameters:

os - The OutputStream to write the data

value - the long value that will be converted to a byte array

bytes - The number of bytes to write the data

Throws:

java.io.IOException - if an error occurs when writing the data or bytes is not in the range of 0 to 8.

writeLongValue

public static void writeLongValue(java.io.OutputStream os,
                  long value)
                           throws java.io.IOException

Writes the specified Long value to the given OutputStream

Parameters:

os - The OutputStream to write the long value

value - The value of the Long

Throws:

java.io.IOException - if an error occurs

writeIndefiniteLength

public static void writeIndefiniteLength(java.io.OutputStream os,
                         byte[] data,
                         int maxByteLength)
                                  throws java.io.IOException

Write the specified data of indefinite length to the given OutputStream. The function will not write more than maxByteLength bytes to the stream.

Note: This function writes the length of the data to the stream before writing the actual data. The size of the field holding the length is always the number of bytes that can hold the specified length. For example, if the length of data was 250 bytes, but the maxByteLength is 2^24-1, the data length value being written would occupy 3 bytes even those only 1 byte actually holds the value.

Parameters:

os - The OutputStream data will be written to

data - The data to write

maxByteLength - The Maximum data Length to write

Throws:

java.io.IOException - if an error occurs

writeDefiniteLength

public static void writeDefiniteLength(java.io.OutputStream os,
                       byte[] data)
                                throws java.io.IOException

Writes a pre-defined number of bytes to the specified output stream. This method just wraps the given OutputStream.

Parameters:

os - The OutputStream to write the data

data - The data to be written.

Throws:

java.io.IOException - if problem occurs when writing to the stream