PulseAuth 1.1.0

PulseAuth

Free, open-source OAuth2 / OpenID Connect authorization server for ASP.NET Core.

PulseAuth is a lightweight alternative to Duende IdentityServer (formerly IdentityServer4) designed to be accessible, free, and easy to set up. It implements the core OAuth2 and OIDC flows on top of ASP.NET Core minimal APIs and integrates natively with ASP.NET Core Identity.

Packages

Supported flows

• Authorization Code + PKCE — secure for web apps, SPAs and mobile
• Client Credentials — service-to-service authentication
• Refresh Token — with optional rotation
• Resource Owner Password — direct username/password login (ideal for React/Angular SPAs that own their own login UI)
• Google ID Token exchange — accept a Google-issued ID token from the frontend SDK and return PulseAuth tokens
• Facebook Access Token exchange — accept a Facebook access token from the frontend SDK and return PulseAuth tokens

OIDC endpoints

Quick start

1. Install

dotnet add package PulseAuth
dotnet add package PulseAuth.Identity
dotnet add package PulseAuth.EntityFramework   # optional, for production

2. Configure Program.cs

using PulseAuth.Constants;
using PulseAuth.Extensions;
using PulseAuth.Builders;
using PulseAuth.Helpers;
using PulseAuth.Models;

var builder = WebApplication.CreateBuilder(args);

// ── ASP.NET Core Identity ────────────────────────────────────────────────────
builder.Services
    .AddDbContext<ApplicationDbContext>(opts =>
        opts.UseSqlServer(builder.Configuration.GetConnectionString("Default")))
    .AddIdentity<ApplicationUser, IdentityRole>()
    .AddEntityFrameworkStores<ApplicationDbContext>();

// ── PulseAuth ────────────────────────────────────────────────────────────────
builder.Services
    .AddPulseAuth(opts =>
    {
        opts.Issuer    = "https://auth.myapp.com";
        opts.LoginPath = "/Account/Login";
    })
    // Signing key — use AddDeveloperSigningCredential() for dev,
    // replace with a persistent key service for production
    .AddDeveloperSigningCredential()
    // In-memory clients — swap for .AddEntityFrameworkStores() in production
    .AddInMemoryClients(new[]
    {
        new Client
        {
            ClientId          = "my-spa",
            ClientName        = "My SPA",
            AllowedGrantTypes = GrantTypes.Code,
            RequirePkce       = true,
            AllowOfflineAccess = true,
            RedirectUris      = ["https://myapp.com/callback"],
            PostLogoutRedirectUris = ["https://myapp.com/"],
            AllowedScopes     = ["openid", "profile", "email", "offline_access"],
        },
        new Client
        {
            ClientId          = "api-service",
            ClientName        = "Backend API",
            ClientSecretHash  = ClientSecretHelper.HashSecret("super-secret"),
            AllowedGrantTypes = GrantTypes.ClientCredentialsOnly,
            AllowedScopes     = ["api"],
        },
    })
    // Connect to ASP.NET Core Identity for user management
    .AddIdentityUsers<ApplicationUser>()
    // Cookie auth for the interactive session
    .AddCookieAuthentication();

// ── External providers (optional) ────────────────────────────────────────────
builder.Services
    .AddPulseAuth()   // returns the existing builder
    .AddGoogle(
        clientId:     builder.Configuration["Auth:Google:ClientId"]!,
        clientSecret: builder.Configuration["Auth:Google:ClientSecret"]!)
    .AddFacebook(
        appId:     builder.Configuration["Auth:Facebook:AppId"]!,
        appSecret: builder.Configuration["Auth:Facebook:AppSecret"]!)
    .AddGitHub(
        clientId:     builder.Configuration["Auth:GitHub:ClientId"]!,
        clientSecret: builder.Configuration["Auth:GitHub:ClientSecret"]!)
    .AddMicrosoft(
        clientId:     builder.Configuration["Auth:Microsoft:ClientId"]!,
        clientSecret: builder.Configuration["Auth:Microsoft:ClientSecret"]!);

var app = builder.Build();

app.UseAuthentication();
app.UseAuthorization();

// Map all PulseAuth endpoints
app.MapPulseAuth();

app.Run();

3. (Production) Switch to persistent stores

builder.Services
    .AddPulseAuth(opts => opts.Issuer = "https://auth.myapp.com")
    .AddEntityFrameworkStores(opts =>
        opts.UseSqlServer(builder.Configuration.GetConnectionString("Default")))
    .AddIdentityUsers<ApplicationUser>();

Apply migrations:

dotnet ef migrations add InitPulseAuth --context PulseAuthDbContext
dotnet ef database update

Hashing client secrets

Never store plaintext secrets. Use the helper:

var (plain, hash) = ClientSecretHelper.GenerateAndHash();
Console.WriteLine($"Secret: {plain}");   // share this with the client
Console.WriteLine($"Hash:   {hash}");    // store this in the DB

// Or hash an existing secret:
string hash = ClientSecretHelper.HashSecret("my-secret");

Custom user store

Implement IUserAuthenticationService to use any user database:

public class MyUserService : IUserAuthenticationService
{
    public Task<UserInfo?> ValidateCredentialsAsync(string user, string pass, CancellationToken ct) { ... }
    public Task<UserInfo?> GetUserByIdAsync(string subjectId, CancellationToken ct) { ... }
    public Task<UserInfo?> FindByExternalProviderAsync(string provider, string externalId, CancellationToken ct) { ... }
    public Task<UserInfo>  AutoProvisionUserAsync(string provider, string externalId, IEnumerable<Claim> claims, CancellationToken ct) { ... }
}

// Register:
builder.Services
    .AddPulseAuth(...)
    .AddUserAuthentication<MyUserService>();

React / Angular SPA — pure API mode

If your frontend is a React or Angular SPA and you want to keep all UI in the frontend (no server-rendered login pages), configure PulseAuth in pure API mode:

Email/password login

Enable the password grant on your client and call /connect/token directly from the SPA:

// Auth server Program.cs
var client = new Client
{
    ClientId          = "mundoecoa-spa",
    AllowedGrantTypes = [GrantTypes.Password, GrantTypes.RefreshToken],
    AllowOfflineAccess = true,
    AllowedScopes     = [StandardScopes.OpenId, StandardScopes.Profile,
                          StandardScopes.Email, StandardScopes.OfflineAccess, "api"],
};

// React / TypeScript
const tokens = await fetch('https://auth.myapp.com/connect/token', {
  method: 'POST',
  headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
  body: new URLSearchParams({
    grant_type: 'password',
    client_id:  'mundoecoa-spa',
    username:   email,
    password:   password,
    scope:      'openid profile email offline_access api',
  }),
}).then(r => r.json());
// tokens.access_token, tokens.refresh_token, tokens.id_token

Google Sign-In (SDK → token exchange)

1. Add the exchange on the auth server:

builder.Services
    .AddPulseAuth(...)
    .AddGoogleTokenExchange(googleClientId: "123-xxx.apps.googleusercontent.com");

2. Enable the grant type on the client:

AllowedGrantTypes = [GrantTypes.Password, GrantTypes.GoogleIdToken, GrantTypes.RefreshToken],

3. From React (using @react-oauth/google or similar):

// After Google Sign-In returns credential (ID token)
const tokens = await fetch('https://auth.myapp.com/connect/token', {
  method: 'POST',
  headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
  body: new URLSearchParams({
    grant_type: 'urn:ietf:params:oauth:grant-type:google_id_token',
    client_id:  'mundoecoa-spa',
    token:      googleCredential,   // from useGoogleLogin / CredentialResponse
    scope:      'openid profile email offline_access api',
  }),
}).then(r => r.json());

Facebook Login (SDK → token exchange)

1. Add the exchange on the auth server:

builder.Services
    .AddPulseAuth(...)
    .AddFacebookTokenExchange(appId: "123456789", appSecret: "your-secret");

2. Enable the grant type on the client:

AllowedGrantTypes = [GrantTypes.Password, GrantTypes.FacebookAccessToken, GrantTypes.RefreshToken],

3. From React (using react-facebook-login or the JS SDK):

// After FB.login() returns authResponse.accessToken
const tokens = await fetch('https://auth.myapp.com/connect/token', {
  method: 'POST',
  headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
  body: new URLSearchParams({
    grant_type: 'urn:ietf:params:oauth:grant-type:facebook_access_token',
    client_id:  'mundoecoa-spa',
    token:      fbAccessToken,
    scope:      'openid profile email offline_access api',
  }),
}).then(r => r.json());

Validating tokens in other microservices

Any microservice in your ecosystem can validate PulseAuth tokens using standard JWT Bearer authentication — no package dependency required:

// In any ASP.NET Core microservice
builder.Services
    .AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
    .AddJwtBearer(opts =>
    {
        // Auth server URL — tokens are validated against its JWKS automatically
        opts.Authority = "https://auth.myapp.com";
        opts.Audience  = "mundoecoa-spa";   // or your client_id
        opts.RequireHttpsMetadata = false;  // only in dev
    });

The microservice downloads the public keys from https://auth.myapp.com/.well-known/jwks and caches them. No shared secrets, no extra packages beyond Microsoft.AspNetCore.Authentication.JwtBearer.

Login page

PulseAuth redirects to LoginPath (default /Account/Login) when the user is not authenticated. Your login page must sign the user in using ASP.NET Core Identity and then redirect back to the returnUrl parameter.

// Example Razor Page
public class LoginModel : PageModel
{
    public async Task<IActionResult> OnPostAsync(string returnUrl = "/")
    {
        var result = await _signInManager.PasswordSignInAsync(Input.Email, Input.Password, false, false);
        if (result.Succeeded)
            return LocalRedirect(returnUrl);

        ModelState.AddModelError(string.Empty, "Invalid login attempt.");
        return Page();
    }
}

External provider callback

After a social login, redirect the user back to the authorize endpoint:

// /Account/ExternalLoginCallback
public async Task<IActionResult> Callback(string returnUrl = "/")
{
    var info = await _signInManager.GetExternalLoginInfoAsync();
    
    // Find or auto-provision the user
    var user = await _pulseAuthUsers.FindByExternalProviderAsync(info.LoginProvider, info.ProviderKey)
            ?? await _pulseAuthUsers.AutoProvisionUserAsync(
                info.LoginProvider, info.ProviderKey, info.Principal.Claims);

    await _signInManager.SignInAsync(identityUser, isPersistent: false);
    return LocalRedirect(returnUrl);
}

💖 Support

This project is developed and maintained by Andrés Mariño. If you find this library useful, consider supporting its continued development:

• Bitcoin (BTC): bc1p9zqgxghkjhauruhsza9n382e6kp5tpj4xtzu2csv4mypsdtdc4tqvdyg86
• Ko-fi:

📝 License

This project is licensed under the MIT License. See the LICENSE file for details.

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