Is there any way to Authenticate B2C application using multiple policies - azure

Question

I am using a B2C login page to authenticate my users. These users have multiple IDP's of their choice as per their business and I created multiple policies with selected IDP's. In the login page based on the user email, I display his login page which has only his relevant IDP's. But in my web application, I can only add one Signup or SignIn policy in my appsettings.json to authenticate the user. Is there any option to have multiple policies in appsettings.json file or any other way to handle this requirement
My Current appsettings.json looks like below
"AzureAdB2C": {
"Instance": "https://login.microsoftonline.com/tfp/",
"ClientId": "******-***-****-****-*******",
"Domain": "mycustomdomain.onmicrosoft.com",
"SignUpSignInPolicyId": "Org-signinsignout"
},

Answer 1

You can invoke a different policy for a different type of user by passing the requested policy from a controller method to the authentication middleware:
public IActionResult LogInForBusinessCustomer(string uiLocale)
{
return LogInFor(Constants.AuthenticationSchemes.B2COpenIdConnect, Constants.Policies.SignUpOrSignInWithWorkAccount, uiLocale);
}
public IActionResult LogInForIndividualCustomer(string uiLocale)
{
return LogInFor(Constants.AuthenticationSchemes.B2COpenIdConnect, Constants.Policies.SignUpOrSignInWithPersonalAccount, uiLocale);
}
public IActionResult LogInForPartner(string uiLocale)
{
return LogInFor(Constants.AuthenticationSchemes.B2BOpenIdConnect, null, uiLocale);
}
private IActionResult LogInFor(string authenticationScheme, string policy)
{
if (!User.Identity.IsAuthenticated)
{
return new ChallengeResult(
authenticationScheme,
new AuthenticationProperties(
new Dictionary<string, string>
{
{Constants.AuthenticationProperties.Policy, policy}
})
{
RedirectUri = Url.Action("LoggedIn", "Account", values: null, protocol: Request.Scheme)
});
}
return RedirectToHome();
}
and then setting the redirection URL for the requested policy in the authentication middleware:
OnRedirectToIdentityProvider = async context =>
{
var policy = context.Properties.Items.ContainsKey(Constants.AuthenticationProperties.Policy) ? context.Properties.Items[Constants.AuthenticationProperties.Policy] : Constants.Policies.SignUpOrSignInWithPersonalAccount;
var configuration = await GetB2COpenIdConnectConfigurationAsync(context, policy);
context.ProtocolMessage.IssuerAddress = configuration.AuthorizationEndpoint;
if (context.Properties.Items.ContainsKey(Constants.AuthenticationProperties.UILocales))
{
context.ProtocolMessage.SetParameter("ui_locales", context.Properties.Items[Constants.AuthenticationProperties.UILocales]);
}
context.ProtocolMessage.SetParameter("dc", "cdm");
context.ProtocolMessage.SetParameter("slice", "001-000");
},
Reference: https://github.com/Azure-Samples/active-directory-external-identities-woodgrove-demo/blob/2b5110c25d1a626bf9b9ac27ecaaabad8b4bccf4/src/WoodGroveGroceriesWebApplication/Startup.cs#L283
Also please check out this thread
Azure B2C - Single App with multiple login for different user types setup in Azure
Hope it helps.