Azure AD B2C Web API Using .NET Core 2 - asp.net

Question

I’m trying to call a Web API from a Web App both protected by Azure AD B2C. The App signs in fine with the Azure sign in page. But when I call my [Authorize] endpoint on my API I get a 401 unauthorized response.
I thought this is supposed to work right out of the box using VS2017 and ASP.NET Core 2.1. When I created both apps I specified “Individual User Accounts” for authentication and “Connect to an existing user store in the cloud”. The examples I’ve found seem to be from .NET Core 1 or older and no longer relevant or using deprecated setups.
I have the App in the API access section with read and write scopes in Azure.
How do I successfully authorize my App to call my API?
Here’s my App Startup.cs:
public void ConfigureServices(IServiceCollection services)
{
services.Configure<CookiePolicyOptions>(options =>
{
// This lambda determines whether user consent for non-essential cookies is needed for a given request.
options.CheckConsentNeeded = context => true;
options.MinimumSameSitePolicy = SameSiteMode.None;
});
services.AddAuthentication(AzureADB2CDefaults.AuthenticationScheme)
.AddAzureADB2C(options => Configuration.Bind("AzureAdB2C", options));
services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1);
}
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
else
{
app.UseExceptionHandler("/Home/Error");
app.UseHsts();
}
app.UseHttpsRedirection();
app.UseStaticFiles();
app.UseCookiePolicy();
app.UseAuthentication();
app.UseMvc(routes =>
{
routes.MapRoute(
name: "default",
template: "{controller=Home}/{action=Index}/{id?}");
});
}
My App appsettings.json:
{
"AzureAdB2C": {
"Instance": "https://myCompanyPassport.b2clogin.com/tfp/",
"ClientId": "51dde0de-a204-4b67-b890-068846e17ff1",
"ClientSecret": "------------------------",
"CallbackPath": "/signin-oidc",
"Domain": "myCompanyPassport.onmicrosoft.com",
"SignUpSignInPolicyId": "B2C_1_myCompanySignUpSignIn",
"ResetPasswordPolicyId": "B2C_1_myCompanyPasswordReset",
"EditProfilePolicyId": "B2C_1_myCompanyProfile",
"TaskServiceUrl": "https://localhost:44337/",
"ApiIdentifier": "https://myCompanyPassport.onmicrosoft.com/taskapi",
"ReadScope": "read",
"WriteScope": "write"
},
"Logging": {
"LogLevel": {
"Default": "Warning"
}
},
"AllowedHosts": "*"
}
Here’s my API Startup.cs:
public void ConfigureServices(IServiceCollection services)
{
services.AddAuthentication(AzureADB2CDefaults.BearerAuthenticationScheme)
.AddAzureADB2CBearer(options => Configuration.Bind("AzureAdB2C", options));
services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1);
}
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
else
{
app.UseHsts();
}
app.UseHttpsRedirection();
app.UseAuthentication();
app.UseMvc();
}
My API appsettings.json:
{
"AzureAdB2C": {
"Instance": "https://myCompanyPassport.b2clogin.com/tfp/",
"ClientId": "213764b3-8c2a-4bf6-9e69-355495a8f14e",
"ClientSecret": "------------------------",
"Domain": "myCompanyPassport.onmicrosoft.com",
"SignUpSignInPolicyId": "B2C_1_myCompanySignUpSignIn",
"ReadScope": "read",
"WriteScope": "write"
},
"Logging": {
"LogLevel": {
"Default": "Warning"
}
},
"AllowedHosts": "*"
}

Answer 1

Did you try this ( addazureadbearer api )
services.AddAuthentication(sharedOptions =>
{
sharedOptions.DefaultScheme = JwtBearerDefaults.AuthenticationScheme;
})
.AddAzureAdBearer(options => Configuration.Bind("AzureAd", options));