public FileMeta3 GetFileMeta()
{
byte metaTag = this._binaryReader.ReadByte();
if (metaTag != 0x42)
{
throw new InvalidDataException($"File {this._fileItem.Name} fails to extract meta");
}
IFileStreamHandler <IDictionary <string, object> > metaHandler =
this._handlerFactory.GetHandler <IDictionary <string, object> >(metaTag);
IDictionary <string, object> metaDict = metaHandler.Handle(this._binaryReader);
if (!(metaDict.ContainsKey("type") && "metadata".Equals(metaDict["type"])))
{
throw new InvalidDataException($"File {this._fileItem.Name} fails to extract meta");
}
return(FileMeta3.fromDictionary(metaDict));
}
public bool ProcessFile(string sourcePath, string destDir, bool respectFileNameInMeta = true)
{
string destPath = null;
try
{
FileItem fi = new FileItem(sourcePath);
using (CloudSyncFile cloudSyncFile = new CloudSyncFile(fi, _handlerFactory))
{
cloudSyncFile.InitParsing();
FileMeta3 fileMeta = cloudSyncFile.GetFileMeta();
//Generate session key and make sure it matches the file
byte[] sessionKeyComputed =
CryptoUtils.RsaOaepDeciper(fileMeta.EncKey2, this._cloudSyncKey.KeyPair.Private);
string sessionKeyHashStrComputed = CryptoUtils.SaltedMd5(
fileMeta.SessionKeyHash.Substring(0, 10), sessionKeyComputed);
if (!fileMeta.SessionKeyHash.Equals(sessionKeyHashStrComputed))
{
throw new InvalidDataException($"File {fi.Name}, Computed session key is incorrect.");
}
//decrypt content
byte[] sessionKeyBytes = BytesUtils.HexStringToByteArray(
Encoding.ASCII.GetString(sessionKeyComputed));
ParametersWithIV keys =
CryptoUtils.DeriveAESKeyParameters(sessionKeyBytes, null);
AesCbcCryptor decryptor =
new AesCbcCryptor(((KeyParameter)keys.Parameters).GetKey(), keys.GetIV());
destPath = Path.Join(destDir,
respectFileNameInMeta ? fileMeta.FileName : Path.GetFileName(sourcePath));
using (var hasher = MD5.Create())
{
using (AesCryptoServiceProvider aes = new AesCryptoServiceProvider())
{
aes.Mode = CipherMode.CBC;
aes.Key = ((KeyParameter)keys.Parameters).GetKey();
aes.IV = keys.GetIV();
//Stopwatch stopwatch = new Stopwatch();
//stopwatch.Start();
//byte[] buffer = new byte[1024 * 1024];
long bytesRead = 0;
ICryptoTransform decoder = aes.CreateDecryptor();
using (CloudSyncPayloadStream cspls =
new CloudSyncPayloadStream(cloudSyncFile.GetDataBlocks(decryptor)))
using (CryptoStream aesStream = new CryptoStream(cspls, decoder, CryptoStreamMode.Read))
using (LZ4DecoderStream lz4ds = LZ4Stream.Decode(aesStream))
using (FileStream writeFs = new FileStream(destPath, FileMode.OpenOrCreate,
FileAccess.ReadWrite, FileShare.ReadWrite, 1024 * 1024))
using (CryptoStream md5HashStream =
new CryptoStream(writeFs, hasher, CryptoStreamMode.Write))
{
lz4ds.CopyTo(md5HashStream, 1024 * 1024);
// int read;
// while ((read = md5HashStream.Read(buffer, 0, buffer.Length)) > 0)
// {
// //do nothing
// bytesRead += read;
// long elapsed = stopwatch.ElapsedMilliseconds;
// if (elapsed > 1000)
// {
// double readInM = (double) bytesRead / 1024.0 / 1024.0/elapsed*1000.0;
// bytesRead = 0;
// Console.WriteLine($"Speed:{readInM} M/s");
// stopwatch.Reset();
// stopwatch.Start();
// }
// }
}
//stopwatch.Stop();
if (!cloudSyncFile.VerifyContentHash(hasher.Hash))
{
throw new InvalidDataException("File Md5 doesn't match.");
}
}
}
return(true);
}
}
catch (Exception ex)
{
if (File.Exists(destPath))
{
File.Delete(destPath);
}
this._exceptionHandler.Handle(ex);
}
return(false);
}
public static FileMeta3 fromDictionary(IDictionary <string, object> dict)
{
FileMeta3 instance = new FileMeta3();
foreach (KeyValuePair <string, object> entry in dict)
{
switch (entry.Key)
{
case "compress":
instance.Compress = (int)entry.Value > 0;
break;
case "digest":
instance.Digest = (string)entry.Value;
break;
case "enc_key1":
instance.EncKey1 = Convert.FromBase64String((string)entry.Value);
break;
case "enc_key2":
instance.EncKey2 = Convert.FromBase64String((string)entry.Value);
break;
case "encrypt":
instance.Encrypt = (int)entry.Value > 0;
break;
case "file_name":
instance.FileName = (string)entry.Value;
break;
case "key1_hash":
instance.Key1Hash = (string)entry.Value;
break;
case "key2_hash":
instance.Key2Hash = (string)entry.Value;
break;
case "salt":
instance.Salt = (string)entry.Value;
break;
case "session_key_hash":
instance.SessionKeyHash = (string)entry.Value;
break;
case "version":
IDictionary <string, object> versionDict = (IDictionary <string, object>)entry.Value;
int major = (int)versionDict["major"];
int minor = (int)versionDict["minor"];
instance.Version = new FileVersion(major, minor);
break;
default:
//TODO log not supported key
break;
}
}
return(instance);
}
