CodeLogic.TwoFactorAuth 4.6.69-preview

.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.
This package has a SemVer 2.0.0 package version: 4.6.69-preview+38521e3.
There is a newer version of this package available.
See the version list below for details. 
dotnet add package CodeLogic.TwoFactorAuth --version 4.6.69-preview
                    


                    

                
NuGet\Install-Package CodeLogic.TwoFactorAuth -Version 4.6.69-preview
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="4.6.69-preview" />
For projects that support PackageReference, copy this XML node into the project file to reference the package. 
<PackageVersion Include="CodeLogic.TwoFactorAuth" Version="4.6.69-preview" />
                    


                            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 4.6.69-preview
                    


                    

                
#r "nuget: CodeLogic.TwoFactorAuth, 4.6.69-preview"
#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@4.6.69-preview
#: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=4.6.69-preview&prerelease
                    


                            Install as a Cake Addin
                        

                    

                
#tool nuget:?package=CodeLogic.TwoFactorAuth&version=4.6.69-preview&prerelease
                    


                            Install as a Cake Tool

CodeLogic.TwoFactorAuth

NuGet License: MIT

TOTP two-factor authentication with QR-code generation for CodeLogic 4 — compatible with Google Authenticator, Authy, and 1Password.

Implements RFC 6238 time-based one-time passwords over Otp.NET and renders provisioning QR codes with QRCoder. Two services are exposed: an authenticator (generate/validate codes) and a QR-code generator.

Install

dotnet add package CodeLogic.TwoFactorAuth

Quick start

await Libraries.LoadAsync<TwoFactorAuthLibrary>();
await CodeLogic.ConfigureAsync();
await CodeLogic.StartAsync();

var tfa = Libraries.Get<TwoFactorAuthLibrary>();

// 1. Enrol: create a key bound to issuer + user (fresh Base32 secret)
TwoFactorKey key = tfa.GenerateNewKey("MyApp", "user@example.com");
//    persist key.SecretKey alongside the user record

// 2. Show a QR code for the authenticator app
Result<string> qr = tfa.GenerateQrCodeDataUri(key);   // data:image/png;base64,...
if (qr.IsSuccess) { /* <img src="qr.Value"> */ }

// 3. Verify a code the user typed
TotpValidationResult check = tfa.ValidateTotp("123456", key.SecretKey);
if (check.IsValid) { /* grant access */ }

Features

  • Secret generation — cryptographically random Base32 TOTP secrets (GenerateSecretKey).
  • Provisioning — GenerateNewKey(issuer, user) returns a TwoFactorKey with a standard otpauth:// ProvisioningUri.
  • Generate & validate — GenerateTotpCode / ValidateTotp with a configurable time step and drift window; validation returns a TotpValidationResult including the matched window offset.
  • Lifetime helpers — GetSecondsUntilExpiry() and GetCurrentTimeWindow().
  • QR rendering — PNG / BMP bytes, Base64, data URI, and save-to-file, with configurable module size and error-correction level.
  • Events — SecretKeyGeneratedEvent and TotpValidatedEvent on the CodeLogic event bus.

Configuration

Auto-generated on first run as config.twofactorauth.json:

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

Documentation

Full guide: CL.TwoFactorAuth documentation

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
4.6.72 177 6/20/2026
4.6.69-preview 35 6/20/2026
4.5.2 105 5/24/2026
4.5.2-preview.68 56 6/20/2026
4.5.1 156 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
4.0.5 106 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/).

## 2026-06-20

### Documentation

- Full rewrite of the README and the `docs/libs/twofactorauth.md` guide to the
 shared house style: a concise, NuGet-rendered README (badges, tagline, install,
 quick start, features, configuration table + JSON, requirements) and a single
 deep documentation page covering the enrolment flow, sign-in validation, the
 `Authenticator` and `QrCode` services, the `TwoFactorKey` /
 `TotpValidationResult` shapes, configuration, events, and the health check.
 No API changes.

## [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).