CodeLogic.TwoFactorAuth 4.5.2-preview.68

.NET 10.0 This package targets .NET 10.0. The package is compatible with this framework or higher.
This is a prerelease version of CodeLogic.TwoFactorAuth.
There is a newer version of this package available.
See the version list below for details. 
dotnet add package CodeLogic.TwoFactorAuth --version 4.5.2-preview.68
                    


                    

                
NuGet\Install-Package CodeLogic.TwoFactorAuth -Version 4.5.2-preview.68
This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package. 
<PackageReference Include="CodeLogic.TwoFactorAuth" Version="4.5.2-preview.68" />
For projects that support PackageReference, copy this XML node into the project file to reference the package. 
<PackageVersion Include="CodeLogic.TwoFactorAuth" Version="4.5.2-preview.68" />
                    


                            Directory.Packages.props
                        

                    

                
<PackageReference Include="CodeLogic.TwoFactorAuth" />
                    


                            Project file
For projects that support Central Package Management (CPM), copy this XML node into the solution Directory.Packages.props file to version the package. 
paket add CodeLogic.TwoFactorAuth --version 4.5.2-preview.68
                    


                    

                
#r "nuget: CodeLogic.TwoFactorAuth, 4.5.2-preview.68"
#r directive can be used in F# Interactive and Polyglot Notebooks. Copy this into the interactive tool or source code of the script to reference the package. 
#:package CodeLogic.TwoFactorAuth@4.5.2-preview.68
#:package directive can be used in C# file-based apps starting in .NET 10 preview 4. Copy this into a .cs file before any lines of code to reference the package. 
#addin nuget:?package=CodeLogic.TwoFactorAuth&version=4.5.2-preview.68&prerelease
                    


                            Install as a Cake Addin
                        

                    

                
#tool nuget:?package=CodeLogic.TwoFactorAuth&version=4.5.2-preview.68&prerelease
                    


                            Install as a Cake Tool

CodeLogic.TwoFactorAuth

NuGet

TOTP two-factor authentication with QR code generation for CodeLogic applications.

Install

dotnet add package CodeLogic.TwoFactorAuth

Quick Start

var tfaLib = new TwoFactorAuthLibrary();
// After library initialization via the CodeLogic framework:

// Generate a new key bound to an issuer + user (creates a fresh Base32 secret)
TwoFactorKey key = tfaLib.GenerateNewKey("MyApp", "user@example.com");

// Persist key.SecretKey alongside the user record for later validation

// Render a QR code as a data URI for an authenticator app (Google Authenticator / Authy / 1Password)
Result<string> qrDataUri = tfaLib.GenerateQrCodeDataUri(key);
if (qrDataUri.IsSuccess)
{
    // Embed qrDataUri.Value in an <img src="..."> tag
}

// Validate a code entered by the user
TotpValidationResult result = tfaLib.ValidateTotp("123456", key.SecretKey);
Console.WriteLine($"Valid: {result.IsValid}");

Features

  • Secret key generation — cryptographically random Base32-encoded TOTP secrets (GenerateSecretKey)
  • Provisioning keys — GenerateNewKey(issuer, user) returns a TwoFactorKey exposing a standard otpauth:// ProvisioningUri
  • TOTP generation & validation — GenerateTotpCode and ValidateTotp with configurable time-step and drift window; validation returns a TotpValidationResult (including the matched window offset)
  • Code lifetime helpers — GetSecondsUntilExpiry() and GetCurrentTimeWindow()
  • QR code rendering — PNG bytes, BMP bytes, Base64, data URI, and save-to-file output with configurable module size and error-correction level
  • Google Authenticator compatible — standard otpauth://totp/... URI format (RFC 6238)
  • Event integration — SecretKeyGeneratedEvent and TotpValidatedEvent are published to the CodeLogic event bus
  • Health check — exercises live TOTP key generation

Services

The library exposes two services plus convenience pass-throughs:

Member Returns Purpose
Authenticator TwoFactorAuthenticator TOTP generation/validation service
QrCode QrCodeGenerator QR code rendering service
GenerateSecretKey() string New Base32 secret
GenerateNewKey(issuer, user) TwoFactorKey New key + provisioning URI
ValidateTotp(code, secretKey) TotpValidationResult Verify a 6-digit code
GenerateQrCodeDataUri(key) Result<string> data:image/png;base64,... URI

TwoFactorAuthenticator

var auth = tfaLib.Authenticator;

string secret = auth.GenerateSecretKey();
Result<string> codeResult = auth.GenerateTotpCode(secret);

// userId is optional — when supplied, a TotpValidatedEvent is published
TotpValidationResult check = auth.ValidateTotp("123456", secret, userId: "alice");

int secondsLeft = auth.GetSecondsUntilExpiry();
long window     = auth.GetCurrentTimeWindow();

QrCodeGenerator

var qr  = tfaLib.QrCode;
var key = tfaLib.GenerateNewKey("MyApp", "user@example.com");

Result<byte[]> png    = qr.GenerateQrCodePng(key);
Result<byte[]> bmp    = qr.GenerateQrCodeBmp(key);
Result<string> base64 = qr.GenerateQrCodeBase64(key);
Result<string> uri    = qr.GenerateQrCodeDataUri(key);
Result         saved  = qr.SaveQrCodeToFile(key, "qrcode.png");

Configuration

Config file: config.twofactorauth.json

{
  "Enabled": true,
  "TimeStepSeconds": 30,
  "WindowSize": 1,
  "QrCodeModuleSize": 20,
  "ErrorCorrectionLevel": "Q"
}
Setting Default Description
Enabled true Master switch; when false the services are not created and the health check reports disabled
TimeStepSeconds 30 TOTP time step in seconds (1–300); must match the authenticator app
WindowSize 1 Steps before/after the current window to accept (0–10); 1 ≈ ±30s drift tolerance
QrCodeModuleSize 20 Pixel size of each QR module (1–100)
ErrorCorrectionLevel Q QR error correction: L (~7%), M (~15%), Q (~25%), H (~30%)

Documentation

Full API docs: https://github.com/Media2A/CodeLogic.Libs

Requirements

License

MIT — see LICENSE

Product Compatible and additional computed target framework versions.
.NET net10.0 is compatible.  net10.0-android was computed.  net10.0-browser was computed.  net10.0-ios was computed.  net10.0-maccatalyst was computed.  net10.0-macos was computed.  net10.0-tvos was computed.  net10.0-windows was computed. 
Compatible target framework(s)
Included target framework(s) (in package)
Learn more about Target Frameworks and .NET Standard.

NuGet packages

This package is not used by any NuGet packages.

GitHub repositories

This package is not used by any popular GitHub repositories.

Version Downloads Last Updated
4.6.72 178 6/20/2026
4.6.69-preview 36 6/20/2026
4.5.2 105 5/24/2026
4.5.2-preview.68 57 6/20/2026
4.5.1 157 5/24/2026
4.5.1-preview.56 97 5/24/2026
4.4.2-preview.53 56 5/24/2026
4.4.1 101 5/24/2026
4.0.5 107 5/15/2026
4.0.4 111 5/9/2026
4.0.3 109 5/9/2026
3.3.1 624 4/18/2026
3.3.0 114 4/18/2026
3.2.11 125 4/18/2026
3.2.10 113 4/18/2026
3.2.9 108 4/18/2026
3.2.8 107 4/18/2026
3.2.7 107 4/18/2026
3.2.6 107 4/18/2026
3.2.5 114 4/18/2026
Loading failed

# CL.TwoFactorAuth — Changelog

All notable changes to **CodeLogic.TwoFactorAuth** are documented here. Versions follow
[Semantic Versioning](https://semver.org/).

## [4.5.2] — 2026-06-20

### Documentation

- Corrected the README and the security guide to match the shipping API. The
 previous docs referenced members and config keys that do not exist
 (`GenerateSecret`, `Validate(secret, token)`, `GetOtpAuthUri`, backup-code
 helpers, and the `Issuer`/`SecretKeyLength`/`TokenValiditySeconds`/
 `AllowedClockSkewSeconds`/`QrCodeSize` settings).
- Documented the real configuration keys: `Enabled`, `TimeStepSeconds`,
 `WindowSize`, `QrCodeModuleSize`, and `ErrorCorrectionLevel`
 (`L`/`M`/`Q`/`H`).
- Documented the `Authenticator` and `QrCode` services and their full surface:
 `GenerateSecretKey`, `GenerateNewKey`, `GenerateTotpCode`, `ValidateTotp`
 (incl. the optional `userId` argument and the `TotpValidationResult` shape),
 `GetSecondsUntilExpiry`, `GetCurrentTimeWindow`, and the QR outputs
 `GenerateQrCodePng` / `GenerateQrCodeBmp` / `GenerateQrCodeBase64` /
 `GenerateQrCodeDataUri` / `SaveQrCodeToFile`.
- Documented the `TwoFactorKey.ProvisioningUri` (`otpauth://`) property, the
 `SecretKeyGeneratedEvent` / `TotpValidatedEvent` bus events, and the actual
 health-check behavior (live TOTP key generation).

## [4.5.0] — 2026-05-24

### Changed

- **Unified versioning.** All CodeLogic.Libs now share a single version line
 controlled by `version.txt` in the repo root. This is a version alignment
 release — no functional changes to this library.
## [4.0.4] — 2026-04-16

### Changed

- README + manifest refresh for the v4 baseline. No functional changes vs 4.0.3.
- `LibraryManifest.Version` now reads from assembly metadata.

## [4.0.2] — 2026-04-09

### Changed

- Annotated 2FA configuration with `[ConfigField]` for the admin UI surface.
- Aligned with the v4 baseline across all libraries.

## [4.0.0] — 2026-04-09

Major rewrite. Republished as v4.0.0 to reset the version line under the
unified v4 baseline. TOTP-based 2FA with QR code generation, backup codes,
and a CodeLogic-native flow for Google Authenticator / Authy / 1Password.

### Notes

- Earlier history is retained in the
 [git log](https://github.com/Media2A/CodeLogic.Libs/commits/main/CL.TwoFactorAuth).