Saml2 Example

Controller.cs

public async Task<IActionResult> DoChallenge(string returnUrl)
{
    var context = await _interaction.GetAuthorizationContextAsync(returnUrl);

    var acrTenantValue = context.AcrValues.First(v => v.StartsWith("tenantId:"));
    var tentantId = acrTenantValue.Split(':')[1];

    // start challenge and roundtrip the return URL and
    var props = new AuthenticationProperties
    {
        RedirectUri = Url.Action("Callback"),
        Items =
        {
            {"returnUrl", returnUrl},
            {"tentantId", tentantId}
        }
    };

    return Challenge(props, "saml2");
}

Startup.cs

services
    .AddAuthentication()
    .AddSaml(options =>
    {
        options.ConfigurationID = properties =>
        {
            if (properties.Items.TryGetValue("tentantId", out var tentantId))
                return tentantId;

            return null;
        };
    });