private DataReader DecodeFile(DataReader reader, FileType containerType, int fileNumber)
{
var header = reader.Size < 4 ? 0 : reader.PeekDword();
var fileType = ((header & 0xffff0000) == (uint)FileType.JH) ? FileType.JH : (FileType)header;
if (fileType == FileType.JH)
{
reader.Position += 4; // skip header
reader = new DataReader(JH.Crypt(reader, (ushort)(((header & 0xffff0000u) >> 16) ^ (header & 0x0000ffffu))));
}
else if (containerType == FileType.AMNC) // AMNC archives are always encoded
{
reader = new DataReader(JH.Crypt(reader, (ushort)fileNumber));
}
header = reader.Size < 4 ? 0 : reader.PeekDword(); // Note: The header might have changed above.
fileType = (FileType)header; // Note: No need to check for JH here as this can not happen.
// See if it is a LOB file
if (fileType == FileType.LOB || fileType == FileType.VOL1)
{
reader.Position += 4; // skip header
uint decodedSize = reader.PeekDword() & 0x00ffffff; // the first byte would contain the offset for the size entry (= 6)
// AMNP archives are always encoded
if (containerType == FileType.AMNP)
{
reader.Position += 4; // skip decoded size
reader = new DataReader(JH.Crypt(reader, (ushort)fileNumber));
reader.Position += 4; // skip encoded size
}
else
{
reader.Position += 8; // skip decoded and encoded size
}
return(Lob.Decompress(reader, decodedSize));
}
else
{
// AMNP archives are always encoded
if (containerType == FileType.AMNP)
{
// ensure and skip the header (should be FileType.None here)
if (reader.ReadDword() != (uint)FileType.None)
{
throw new AmbermoonException(ExceptionScope.Data, "Invalid AMNP file data.");
}
reader = new DataReader(JH.Crypt(reader, (ushort)fileNumber));
}
return(reader);
}
}
// Test encryption
static void TestCryptography()
{
IHashProvider p;
// Generate a random set of bytes
byte[] Bytes = SecureRandom.Bytes(32);
// Write bytes to console
Console.WriteLine($"Randomly generated bytes: {Encoding.ByteArrayToHexString(Bytes)}");
// Keccak the generated bytes
byte[] KeccakBytes = Keccak.keccak(Bytes);
// Write keccak bytes to console
Console.WriteLine($"Keccak: {Encoding.ByteArrayToHexString(KeccakBytes)}");
// Blake256 the generated bytes
p = new Blake();
byte[] BlakeBytes = p.Hash(Bytes);
// Write blake256 bytes to console
Console.WriteLine($"Blake: {Encoding.ByteArrayToHexString(BlakeBytes)}");
// Skein the generated bytes
p = new Skein();
byte[] SkeinBytes = p.Hash(Bytes);
// Write skein bytes to console
Console.WriteLine($"Skein: {Encoding.ByteArrayToHexString(SkeinBytes)}");
// Groestl the generated bytes
p = new Groestl();
byte[] GroestlBytes = p.Hash(Bytes);
// Write groestl bytes to console
Console.WriteLine($"Groestl: {Encoding.ByteArrayToHexString(GroestlBytes)}");
// JH the generated bytes
p = new JH();
byte[] JHBytes = p.Hash(Bytes);
// Write JH bytes to console
Console.WriteLine($"JH: {Encoding.ByteArrayToHexString(JHBytes)}");
// Base58 the generated bytes
string Base58String = Base58.Encode(Bytes);
// Write base58 bytes to console
Console.WriteLine($"Base58: {Base58String}");
Console.WriteLine();
}
/* CryptoNight Step 5: Apply Keccak to the state again, and then
* use the resulting data to select which of four finalizer
* hash functions to apply to the data (Blake, Groestl, JH,
* or Skein). Use this hash to squeeze the state array down
* to the final 32 byte hash output.
*/
public static byte[] HashFinalState(CNState cnState)
{
/* Get the state buffer as an array of ulongs rather than bytes */
ulong[] hashState = cnState.GetHashState();
Keccak.Keccakf(hashState, 24);
/* Set the state buffer from the coerced hash state */
cnState.SetHashState(hashState);
/* Get the actual state buffer finally */
byte[] state = cnState.GetState();
/* Choose the final hashing function to use based on the value of
* state[0] */
switch (state[0] % 4)
{
case 0:
{
return(Blake.Hash(state));
}
case 1:
{
return(Groestl.Hash(state));
}
case 2:
{
return(JH.Hash(state));
}
default:
{
return(Skein.Hash(state));
}
}
}
