private static void SaveKeyData(RSACrypt provider, string path, DataTypeFlag saveInfoFlag)
{
using (var bw = new BinaryWriter(File.Create(path)))
{
bw.Write((byte)Opcode.KeyLength);
bw.Write(provider.ExportKeyLenght());
if (Convert.ToBoolean(saveInfoFlag & DataTypeFlag.PublicKey))
{
using (var key = provider.ExportKey(false))
{
var keyBuffer = key.GetBuffer();
bw.Write((byte)Opcode.PublicKey);
bw.Write(keyBuffer.Length);
bw.Write(keyBuffer);
}
}
if (Convert.ToBoolean(saveInfoFlag & DataTypeFlag.PrivateKey))
{
using (var key = provider.ExportKey(true))
{
var keyBuffer = key.GetBuffer();
bw.Write((byte)Opcode.PrivateKey);
bw.Write(keyBuffer.Length);
bw.Write(keyBuffer);
}
}
}
}
public static async Task EncryptFileAsync(string filePath, string saveKeyDataPath, DataTypeFlag saveInfoFlag)
{
if (!File.Exists(filePath))
{
throw new FileNotFoundException("File not found");
}
using (var stream = new FileStream(filePath, FileMode.Open, FileAccess.ReadWrite, FileShare.Read))
{
using (var provider = new RSACrypt())
{
byte[] fileBuffer = new byte[stream.Length];
await stream.ReadAsync(fileBuffer, 0, fileBuffer.Length);
var encryptBuffer = provider.Encrypt(fileBuffer);
stream.Seek(0, SeekOrigin.Begin);
stream.SetLength(encryptBuffer.Length);
await stream.WriteAsync(encryptBuffer, 0, encryptBuffer.Length);
Array.Clear(fileBuffer, 0, fileBuffer.Length);
SaveKeyData(provider, saveKeyDataPath, saveInfoFlag);
}
}
}
private static (int, byte[], byte[]) ReadKeyData(RSACrypt provider, string path, DataTypeFlag saveTypeFlag)
{
int?keyLenght = null;
byte[] publicKey = null;
byte[] privateKey = null;
if (!File.Exists(path))
{
throw new FileNotFoundException("Key file not found");
}
using (var br = new BinaryReader(File.Open(path, FileMode.Open)))
{
while (br.BaseStream.Position < br.BaseStream.Length)
{
Opcode opcode = (Opcode)br.ReadByte();
switch (opcode)
{
case Opcode.KeyLength:
if (keyLenght == null)
{
keyLenght = br.ReadInt32();
}
break;
case Opcode.PublicKey:
if (publicKey == null)
{
publicKey = br.ReadBytes(br.ReadInt32());
}
break;
case Opcode.PrivateKey:
if (privateKey == null)
{
privateKey = br.ReadBytes(br.ReadInt32());
}
break;
default:
throw new Exception("Detected unknown opcode");
}
}
}
if (keyLenght == null)
{
throw new Exception("Key lenght fault");
}
return(keyLenght.Value, publicKey, privateKey);
}
