public static ulong? ParseCounter(string strCounter, OtpDataFmt fmt)
{
byte[] pb = ParseKey(strCounter, fmt);
if(pb == null) return null;
if(pb.Length > 8) return null;
Array.Reverse(pb); // Big endian -> little endian
byte[] pb8 = new byte[8];
Array.Copy(pb, 0, pb8, 0, pb.Length);
return MemUtil.BytesToUInt64(pb8); // Little endian
}
public static byte[] ParseKey(string strKey, OtpDataFmt fmt)
{
if(strKey == null) { Debug.Assert(false); return null; }
strKey = strKey.Trim();
if(strKey.Length == 0) return null; // No assert
if(fmt == OtpDataFmt.Hex)
{
strKey = strKey.Replace(" ", string.Empty);
strKey = strKey.Replace("\t", string.Empty);
strKey = strKey.Replace("\r", string.Empty);
strKey = strKey.Replace("\n", string.Empty);
if((strKey.Length % 2) == 1) strKey = "0" + strKey;
return MemUtil.HexStringToByteArray(strKey);
}
else if(fmt == OtpDataFmt.Base64)
{
try { return Convert.FromBase64String(strKey); }
catch(Exception) { }
}
else if(fmt == OtpDataFmt.Base32)
return ParseBase32(strKey);
else if(fmt == OtpDataFmt.Utf8)
{
try { return StrUtil.Utf8.GetBytes(strKey); }
catch(Exception) { }
}
else if(fmt == OtpDataFmt.Dec)
{
ulong u;
if(ulong.TryParse(strKey, out u))
{
byte[] pb = MemUtil.UInt64ToBytes(u);
Array.Reverse(pb); // Little endian -> big endian
return pb;
}
}
return null;
}
/*
private static byte[] Open(KeyProviderQueryContext ctx, OtpInfo otpInfo)
{
if(otpInfo.Type != ProvType)
{
MessageService.ShowWarning("Unknown OTP generator type!");
return null;
}
OtpKeyPromptForm dlg = new OtpKeyPromptForm();
dlg.InitEx(otpInfo, ctx);
if(UIUtil.ShowDialogAndDestroy(dlg) != DialogResult.OK)
return null;
if(!CreateAuxFile(otpInfo, ctx)) return null;
return otpInfo.Secret;
}
* */
/// <summary>
/// Sets the "Secret" field in otpInfo based on the list of entered OTPs (lOtps) or the entered secret itself which is in format fmt
/// </summary>
/// based on the code in OtpKeyPromptForm.cs
public void SetSecret(OtpInfo otpInfo, List<string> lOtps, string secret, OtpDataFmt? fmt)
{
byte[] pbSecret = EncodingUtil.ParseKey(secret,
(fmt.HasValue ? fmt.Value : OtpDataFmt.Hex));
if (pbSecret != null)
{
otpInfo.Secret = pbSecret;
return;
}
if (!string.IsNullOrEmpty(otpInfo.EncryptedSecret)) // < v2.0
{
byte[] pbKey32 = OtpUtil.KeyFromOtps(lOtps.ToArray(), 0,
lOtps.Count, Convert.FromBase64String(
otpInfo.TransformationKey), otpInfo.TransformationRounds);
if (pbKey32 == null) throw new InvalidOperationException();
pbSecret = OtpUtil.DecryptData(otpInfo.EncryptedSecret,
pbKey32, Convert.FromBase64String(otpInfo.EncryptionIV));
if (pbSecret == null) throw new InvalidOperationException();
otpInfo.Secret = pbSecret;
otpInfo.Counter += (ulong) otpInfo.OtpsRequired;
}
else // >= v2.0, supporting look-ahead
{
bool bSuccess = false;
for (int i = 0; i < otpInfo.EncryptedSecrets.Count; ++i)
{
OtpEncryptedData d = otpInfo.EncryptedSecrets[i];
pbSecret = OtpUtil.DecryptSecret(d, lOtps.ToArray(), 0,
lOtps.Count);
if (pbSecret != null)
{
otpInfo.Secret = pbSecret;
otpInfo.Counter += ((ulong) otpInfo.OtpsRequired +
(ulong) i);
bSuccess = true;
break;
}
}
if (!bSuccess) throw new InvalidOperationException();
}
}
