private static bool IsPreHashingRequired(string filePath)
{
int oneGibibyte = 1024 * Constants.Mebibyte;
long fileSize = FileHandling.GetFileLength(filePath);
return(fileSize >= oneGibibyte);
}
private static byte[] EncryptFileHeader(string inputFilePath, byte[] ephemeralPublicKey, byte[] dataEncryptionKey, byte[] nonce, byte[] keyEncryptionKey)
{
long fileLength = FileHandling.GetFileLength(inputFilePath);
byte[] lastChunkLength = BitConversion.GetBytes(Convert.ToInt32(fileLength % Constants.FileChunkSize));
byte[] fileNameLength = FileHeaders.GetFileNameLength(inputFilePath);
byte[] fileHeader = Arrays.Concat(lastChunkLength, fileNameLength, dataEncryptionKey);
byte[] additionalData = HeaderEncryption.ComputeAdditionalData(fileLength, ephemeralPublicKey);
return(HeaderEncryption.Encrypt(fileHeader, nonce, keyEncryptionKey, additionalData));
}
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[] GetAdditionalData(string inputFilePath)
{
byte[] magicBytes = FileHeaders.ReadMagicBytes(inputFilePath);
byte[] formatVersion = FileHeaders.ReadFileFormatVersion(inputFilePath);
FileHeaders.ValidateFormatVersion(inputFilePath, formatVersion, Constants.EncryptionVersion);
long fileLength = FileHandling.GetFileLength(inputFilePath);
int headersLength = FileHeaders.GetHeadersLength();
byte[] ciphertextLength = BitConverter.GetBytes(fileLength - headersLength);
return(Utilities.ConcatArrays(magicBytes, formatVersion, ciphertextLength));
}
private static byte[] GetFileBytes(string filePath, bool preHashed)
{
int oneGibibyte = 1024 * Constants.Mebibyte;
long fileSize = FileHandling.GetFileLength(filePath);
if (fileSize >= oneGibibyte || preHashed)
{
using var fileStream = new FileStream(filePath, FileMode.Open, FileAccess.ReadWrite, FileShare.Read, Constants.FileStreamBufferSize, FileOptions.SequentialScan);
return(Blake2.Hash(fileStream));
}
return(File.ReadAllBytes(filePath));
}
private static IEnumerable <string> GetFileEncryptionErrors(char[] password, string keyfilePath, string[] filePaths)
{
if (password.Length == 0 && string.IsNullOrEmpty(keyfilePath))
{
yield return("Please specify whether to use a password and/or keyfile.");
}
if (File.Exists(keyfilePath))
{
long keyfileLength = FileHandling.GetFileLength(keyfilePath);
if (keyfileLength < Constants.KeyfileLength)
{
yield return("Please specify a keyfile that is at least 64 bytes in size.");
}
}
if (filePaths == null)
{
yield return(ValidationMessages.FilePath);
}
}
private static IEnumerable <string> GetFileEncryptionErrors(char[] password, string keyfilePath, string[] filePaths)
{
if (password.Length == 0 && string.IsNullOrEmpty(keyfilePath))
{
yield return(ValidationMessages.PasswordOrKeyfile);
}
if (File.Exists(keyfilePath))
{
long keyfileLength = FileHandling.GetFileLength(keyfilePath);
if (keyfileLength < Constants.KeyfileLength)
{
yield return("Please specify a keyfile that is at least 64 bytes in size.");
}
}
else if (Path.EndsInDirectorySeparator(keyfilePath) && !Directory.Exists(keyfilePath))
{
yield return("Please specify a valid keyfile directory.");
}
if (filePaths == null)
{
yield return(ValidationMessages.FilePath);
}
}
