public static byte[] KeyEncryptionKey(byte[] sharedSecret, byte[] ephemeralSharedSecret, byte[] salt)
{
byte[] inputKeyingMaterial = Utilities.ConcatArrays(sharedSecret, ephemeralSharedSecret);
byte[] keyEncryptionKey = Blake2.KeyDerivation(inputKeyingMaterial, salt, Constants.EncryptionKeyLength);
Utilities.ZeroArray(ephemeralSharedSecret);
Utilities.ZeroArray(inputKeyingMaterial);
return(keyEncryptionKey);
}
public static byte[] KeyEncryptionKey(byte[] sharedSecret, byte[] ephemeralSharedSecret, byte[] salt)
{
byte[] inputKeyingMaterial = Arrays.Concat(sharedSecret, ephemeralSharedSecret);
byte[] keyEncryptionKey = Blake2.KeyDerivation(inputKeyingMaterial, salt, Constants.EncryptionKeyLength);
CryptographicOperations.ZeroMemory(ephemeralSharedSecret);
CryptographicOperations.ZeroMemory(inputKeyingMaterial);
return(keyEncryptionKey);
}
public static byte[] Hash(char[] password)
{
if (password.Length == 0)
{
return(null);
}
byte[] passwordBytes = GetPasswordBytes(password);
return(Blake2.Hash(passwordBytes));
}
private static byte[] GetFileBytes(string filePath, bool preHash)
{
if (!preHash)
{
return(File.ReadAllBytes(filePath));
}
using var fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.Read, Constants.FileStreamBufferSize, FileOptions.SequentialScan);
return(Blake2.Hash(fileStream));
}
public static byte[] ReadKeyfile(string keyfilePath)
{
using var keyfile = new FileStream(keyfilePath, FileMode.Open, FileAccess.Read, FileShare.Read, Constants.FileStreamBufferSize, FileOptions.SequentialScan);
if (keyfile.Length == Constants.KeyfileLength)
{
byte[] keyfileBytes = new byte[Constants.KeyfileLength];
keyfile.Read(keyfileBytes, offset: 0, keyfileBytes.Length);
return(keyfileBytes);
}
return(Blake2.Hash(keyfile));
}
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));
}
public static bool Compare(char[] a, char[] b)
{
// Constant time comparison
byte[] aBytes = Encoding.UTF8.GetBytes(a);
byte[] aHash = Blake2.Hash(aBytes);
CryptographicOperations.ZeroMemory(aBytes);
byte[] bBytes = Encoding.UTF8.GetBytes(b);
byte[] bHash = Blake2.Hash(bBytes);
CryptographicOperations.ZeroMemory(bBytes);
bool equal = Utilities.Compare(aHash, bHash);
CryptographicOperations.ZeroMemory(aHash);
CryptographicOperations.ZeroMemory(bHash);
return(equal);
}
private static byte[] CombineKeyfileAndPassword(byte[] passwordBytes, byte[] keyfileBytes)
{
passwordBytes = Blake2.KeyedHash(passwordBytes, keyfileBytes);
Utilities.ZeroArray(keyfileBytes);
return(passwordBytes);
}
private static byte[] CombineKeyfileAndPassword(byte[] passwordBytes, byte[] keyfileBytes)
{
passwordBytes = Blake2.KeyedHash(passwordBytes, keyfileBytes);
CryptographicOperations.ZeroMemory(keyfileBytes);
return(passwordBytes);
}
public static byte[] ReadKeyfile(string keyfilePath)
{
using var keyfile = new FileStream(keyfilePath, FileMode.Open, FileAccess.Read, FileShare.Read, Constants.FileStreamBufferSize, FileOptions.SequentialScan);
return Blake2.Hash(keyfile);
}
public static byte[] KeyEncryptionKey(byte[] ephemeralSharedSecret, byte[] salt)
{
byte[] keyEncryptionKey = Blake2.KeyDerivation(ephemeralSharedSecret, salt, Constants.EncryptionKeyLength);
Utilities.ZeroArray(ephemeralSharedSecret);
return(keyEncryptionKey);
}
public static byte[] KeyEncryptionKey(byte[] ephemeralSharedSecret, byte[] salt)
{
byte[] keyEncryptionKey = Blake2.KeyDerivation(ephemeralSharedSecret, salt, Constants.EncryptionKeyLength);
CryptographicOperations.ZeroMemory(ephemeralSharedSecret);
return(keyEncryptionKey);
}
