/// <summary>
/// Writes <see cref="DataPack"/> to stream
/// </summary>
/// <param name="dataPack">Data</param>
/// <param name="stream">Stream where <see cref="DataPack"/> is written to</param>
/// <param name="signAlgorithm">Sign algorithm if needed</param>
public void Write(DataPack dataPack, Stream stream, ISignAlgorithm signAlgorithm = null)
{
if (stream == null)
{
throw new ArgumentNullException("stream");
}
if (dataPack == null)
{
throw new ArgumentNullException("dataPack");
}
if (!stream.CanSeek)
{
throw new InvalidOperationException("Stream doesn't support seeking.");
}
if (!stream.CanWrite)
{
throw new InvalidOperationException("Stream doesn't support writing.");
}
using (var wrapper = new NonClosingStreamWrapper(stream)) // To prevent source stream from closing by BinaryWriter
using (var bw = new BinaryWriter(wrapper))
{
// Size of prefix
bw.Write(dataPack.PrefixSize);
// Prefix of data
bw.Write(dataPack.GetPrefix(), 0, dataPack.PrefixSize);
uint signInfoAddress = 0;
uint dataSizeAddress = 0;
if (signAlgorithm == null)
{
// Stream not signed
bw.Write((byte)0);
}
else
{
// Stream is signed
bw.Write((byte)1);
signInfoAddress = GetAddress(bw);
bw.Write(0); // Protected data size
bw.Write(0); // Sign size
dataSizeAddress = GetAddress(bw) - 8;
}
// Create implicit properties
var implicitProperties = new Properties();
if (dataPack.DateCreate != null)
{
implicitProperties["DateCreate"] = dataPack.DateCreate.Value.ToString(Consts.DateTimeFormat, CultureInfo.InvariantCulture);
}
if (dataPack.FileId != null)
{
implicitProperties["FileId"] = dataPack.FileId != null
? dataPack.FileId.Value.ToString()
: null;
}
if (dataPack.Description != null)
{
implicitProperties["Description"] = dataPack.Description;
}
// Info section implicit properties
var properties = implicitProperties.GetPropertiesList();
bw.Write(InfoSection);
uint address = GetAddress(bw);
bw.Write(0u);
ushort cnt = (ushort)properties.Count;
bw.Write(cnt);
for (ushort i = 0; i < cnt; i++)
{
Serializer.SerializeWithLengthPrefix(wrapper, properties[i], PrefixStyle.Base128);
}
WriteSize(bw, address, address + 4);
// Info section with data headers info
bw.Write(InfoSection);
address = GetAddress(bw);
bw.Write(0u);
cnt = (ushort)dataPack.Headers.Count;
bw.Write(cnt);
for (ushort i = 0; i < cnt; i++)
{
Serializer.SerializeWithLengthPrefix(wrapper, dataPack.Headers[i], PrefixStyle.Base128);
}
WriteSize(bw, address, address + 4);
// Header section with data properties info
properties = dataPack.Properties.GetPropertiesList();
bw.Write(InfoSection);
address = GetAddress(bw);
bw.Write(0u);
cnt = (ushort)properties.Count;
bw.Write(cnt);
for (ushort i = 0; i < cnt; i++)
{
Serializer.SerializeWithLengthPrefix(wrapper, properties[i], PrefixStyle.Base128);
}
WriteSize(bw, address, address + 4);
// Header section with data dataPart's info
bw.Write(InfoSection);
var dataPartAddress = GetAddress(bw);
bw.Write(0u);
cnt = (ushort)dataPack.DataParts.Count;
bw.Write(cnt);
for (ushort i = 0; i < cnt; i++)
{
bw.Write(0u);
bw.Write((ushort)0);
bw.Write(0u);
bw.Write(0u);
bw.Write((ushort)0);
bw.Write(0u);
bw.Write(0u);
bw.Write(0u);
}
WriteSize(bw, dataPartAddress, dataPartAddress + 4);
bw.Write(DataSection);
address = GetAddress(bw);
bw.Write(0u);
for (ushort i = 0; i < cnt; i++)
{
WriteDataPart(bw, dataPartAddress + 6, i, dataPack);
}
WriteSize(bw, address, address + 4);
bw.Seek(0, SeekOrigin.End);
bw.Flush();
if (signAlgorithm != null)
{
uint protectedDataSize = GetAddress(bw) - dataSizeAddress;
wrapper.Position = dataSizeAddress;
bw.Write(protectedDataSize);
bw.Flush();
byte[] sign;
using (var filter = new FilteredStream(wrapper, dataSizeAddress, protectedDataSize))
{
sign = signAlgorithm.GetSign(filter);
}
wrapper.Seek(0, SeekOrigin.End);
bw.Write(sign, 0, sign.Length);
bw.Flush();
wrapper.Position = signInfoAddress;
bw.Write((uint)sign.Length);
bw.Flush();
wrapper.Seek(0, SeekOrigin.End);
}
}
}
/// <summary>
/// Sign source <see cref="DataPack"/> stream using given sign algorithm and outputs result to destinationStream
/// </summary>
/// <param name="prefixSize">Size of file prefix</param>
/// <param name="signAlgorithm">Sign algorithm</param>
/// <param name="sourceStream">Source stream</param>
/// <param name="destinationStream">Destination stream</param>
public static void Sign(uint prefixSize, ISignAlgorithm signAlgorithm, Stream sourceStream, Stream destinationStream)
{
if (signAlgorithm == null)
{
throw new ArgumentNullException("signAlgorithm");
}
if (sourceStream == null)
{
throw new ArgumentNullException("sourceStream");
}
if (destinationStream == null)
{
throw new ArgumentNullException("destinationStream");
}
var position = sourceStream.Position;
if (!sourceStream.CanSeek)
{
throw new InvalidOperationException("Source stream doesn't support seeking.");
}
if (!sourceStream.CanRead)
{
throw new InvalidOperationException("Source stream doesn't support reading.");
}
if (!destinationStream.CanSeek)
{
throw new InvalidOperationException("Destination stream doesn't support seeking.");
}
if (!destinationStream.CanRead)
{
throw new InvalidOperationException("Destination stream doesn't support reading.");
}
if (!destinationStream.CanWrite)
{
throw new InvalidOperationException("Destination stream doesn't support writing.");
}
sourceStream.Seek(prefixSize + 1, SeekOrigin.Current);
int isSignedByte = sourceStream.ReadByte();
if (isSignedByte == 1)
{
throw new InvalidOperationException("Source stream already signed.");
}
sourceStream.Position = position;
var buffer = BufferProvider.Current.TakeBuffer();
try
{
int byteCount;
uint prefixBytesLeft = prefixSize + 1;
while ((byteCount = sourceStream.Read(buffer, 0, (int)Math.Min(buffer.Length, prefixBytesLeft))) > 0)
{
destinationStream.Write(buffer, 0, byteCount);
prefixBytesLeft -= (uint)byteCount;
if (prefixBytesLeft == 0)
{
break;
}
}
using (var wrapper = new NonClosingStreamWrapper(destinationStream)) // To prevent stream from closing by BinaryWriter
using (var bw = new BinaryWriter(wrapper))
{
bw.Write((byte)1);
uint signInfoAddress = GetAddress(bw);
bw.Write(0); // Protected data size
bw.Write(0); // Sign size
uint dataSizeAddress = GetAddress(bw) - 8;
while ((byteCount = sourceStream.Read(buffer, 0, buffer.Length)) > 0)
{
wrapper.Write(buffer, 0, byteCount);
}
wrapper.Flush();
uint protectedDataSize = GetAddress(bw) - dataSizeAddress;
wrapper.Position = dataSizeAddress;
bw.Write(protectedDataSize);
bw.Flush();
byte[] sign;
using (var filter = new FilteredStream(wrapper, dataSizeAddress, protectedDataSize))
{
sign = signAlgorithm.GetSign(filter);
}
wrapper.Seek(0, SeekOrigin.End);
bw.Write(sign, 0, sign.Length);
bw.Flush();
wrapper.Position = signInfoAddress;
bw.Write((uint)sign.Length);
bw.Flush();
wrapper.Seek(0, SeekOrigin.End);
}
}
finally
{
BufferProvider.Current.ReturnBuffer(buffer);
}
}
