private static byte[] EncryptFileHeader(string inputFilePath, byte[] dataEncryptionKey, byte[] nonce, byte[] keyEncryptionKey)
{
byte[] keyCommitmentBlock = ChunkHandling.GetKeyCommitmentBlock();
long fileLength = FileHandling.GetFileLength(inputFilePath);
byte[] lastChunkLength = BitConverter.GetBytes(Convert.ToInt32(fileLength % Constants.FileChunkSize));
byte[] fileNameLength = FileHeaders.GetFileNameLength(inputFilePath);
byte[] fileHeader = Utilities.ConcatArrays(keyCommitmentBlock, lastChunkLength, fileNameLength, dataEncryptionKey);
byte[] additionalData = HeaderEncryption.ComputeAdditionalData(fileLength);
return(HeaderEncryption.Encrypt(fileHeader, nonce, keyEncryptionKey, additionalData));
}
public static byte[] Encrypt(byte[] passwordBytes, byte[] privateKey, byte[] keyAlgorithm)
{
byte[] salt = Generate.Salt();
byte[] key = Argon2.DeriveKey(passwordBytes, salt);
Utilities.ZeroArray(passwordBytes);
byte[] nonce = Generate.Nonce();
byte[] additionalData = Utilities.ConcatArrays(keyAlgorithm, Constants.PrivateKeyVersion);
byte[] keyCommitmentBlock = ChunkHandling.GetKeyCommitmentBlock();
privateKey = Utilities.ConcatArrays(keyCommitmentBlock, privateKey);
byte[] encryptedPrivateKey = SecretAeadXChaCha20Poly1305.Encrypt(privateKey, nonce, key, additionalData);
Utilities.ZeroArray(privateKey);
Utilities.ZeroArray(key);
return(Utilities.ConcatArrays(additionalData, salt, nonce, encryptedPrivateKey));
}
