/*
* File structure
* Byte 1 to 4 = ConfigOffsetLength int32
* Section2: Salt1
* Section3: Salt2
* Section4: PasswordHash 64 bytes
* section5: EncodedBlockSize 4 byte
* section6: Sha256 EncodedDataValidation 256 bytes
* section7: encodedBlock to EOF
*
*
* Byte
*/
public bool LoadSettings(string filename, string password)
{
FileStream fs = null;
try
{
fs = File.OpenRead(filename);
int bytesRead = 0;
var buffer = new byte[4];
bytesRead = fs.Read(buffer, 0, 4);
int configOffsetBytes = BitConverter.ToInt32(buffer, 0);
if (configOffsetBytes <= 0 || configOffsetBytes > SaltByteLength * 2 + 64)
{
throw new DataMisalignedException("configOffsetBytes is invalid");
}
buffer = new byte[configOffsetBytes];
bytesRead += fs.Read(buffer, 0, buffer.Length);
byte[] salt1Bytes = new byte[SaltByteLength];
byte[] salt2Bytes = new byte[SaltByteLength];
byte[] passwordHashBytes = new byte[64];
Buffer.BlockCopy(buffer, 0, salt1Bytes, 0, SaltByteLength);
Buffer.BlockCopy(buffer, SaltByteLength, salt2Bytes, 0, SaltByteLength);
Buffer.BlockCopy(buffer, SaltByteLength * 2, passwordHashBytes, 0, passwordHashBytes.Length);
buffer = new byte[4];
bytesRead += fs.Read(buffer, 0, 4);
int encodedBlockSize = BitConverter.ToInt32(buffer, 0);
if (encodedBlockSize <= 0 || encodedBlockSize > fs.Length - bytesRead)
{
throw new DataMisalignedException("configOffsetBytes is invalid");
}
buffer = new byte[encodedBlockSize];
fs.Read(buffer, 0, buffer.Length);
_otpSettings = new OTPSettings(null, salt1Bytes, salt2Bytes);
if (_otpSettings.Decode(buffer, password))
{
Initialized = true;
}
}
catch (Exception ex)
{
Log.Error(ex, "Exception in LoadSettings()");
return(false);
}
finally
{
fs?.Close();
}
return(true);
}
/// <summary>
/// Create a new instance of otpSettings
/// </summary>
/// <param name="password"></param>
/// <returns>Password hash</returns>
public string Create(string password, Authenticator.SecretKeyLength keyLength)
{
using (var randomNumberGenerator = RandomNumberGenerator.Create())
{
byte[] salt1Bytes = new byte[SaltByteLength];
byte[] salt2Bytes = new byte[SaltByteLength];
byte[] passwordBytes = GeneralConverters.GetByteArrayFromString(password);
randomNumberGenerator.GetBytes(salt1Bytes);
randomNumberGenerator.GetBytes(salt2Bytes);
PasswordHash = CreatePasswordHash(salt1Bytes, salt2Bytes, passwordBytes);
_otpSettings = new OTPSettings(Authenticator.GenerateKey(keyLength), salt1Bytes, salt2Bytes);
Initialized = true;
return(PasswordHash);
}
}
public OTPGenerator(OTPSettings settings)
{
_random = new Random(Guid.NewGuid().GetHashCode());
_activeTime = settings.OTPLifeTime;
_numberOfDigits = settings.NumberOfDigits;
}
private OTPConfigService()
{
_otpSettings = null;
}
public static void AddOTPGenerator(this IServiceCollection services, OTPSettings settings)
{
var generator = new OTPGenerator(settings);
services.AddTransient <IOTPGenerator>(provider => { return(generator); });
}
