Defining Clients

Clients represent applications that can request tokens from your identityserver.

The details vary, but you typically define the following common settings for a client:

  • a unique client ID
  • a secret if needed
  • the allowed interactions with the token service (called a grant type)
  • a network location where identity and/or access token gets sent to (called a redirect URI)
  • a list of scopes (aka resources) the client is allowed to access

Note

At runtime, clients are retrieved via an implementation of the IClientStore. This allows loading them from arbitrary data sources like config files or databases. For this document we gonna use the in-memory version of the client store. You can wire up the in-memory store in ConfigureServices via the AddInMemoryClients extensions method.

Defining a client for server to server communication

In this scenario no interactive user is present - a service (aka client) wants to communicate with an API (aka scope):

public class Clients
{
    public static IEnumerable<Client> Get()
    {
        return new List<Client>
        {
            new Client
            {
                ClientId = "service.client",
                ClientSecrets = { new Secret("secret".Sha256()) },

                AllowedGrantTypes = GrantTypes.ClientCredentials,
                AllowedScopes = { "api1", "api2.read_only" }
            }
        };
    }
}

Defining browser-based JavaScript client (e.g. SPA) for user authentication and delegated access and API

This client uses the so called implicit flow to request an identity and access token from JavaScript:

var jsClient = new Client
{
    ClientId = "js",
    ClientName = "JavaScript Client",
    ClientUri = "http://identityserver.io",

    AllowedGrantTypes = GrantTypes.Implicit,
    AllowAccessTokensViaBrowser = true,

    RedirectUris =           { "http://localhost:7017/index.html" },
    PostLogoutRedirectUris = { "http://localhost:7017/index.html" },
    AllowedCorsOrigins =     { "http://localhost:7017" },

    AllowedScopes =
    {
        IdentityServerConstants.StandardScopes.OpenId,
        IdentityServerConstants.StandardScopes.Profile,
        IdentityServerConstants.StandardScopes.Email,

        "api1", "api2.read_only"
    }
};

Defining a server-side web application (e.g. MVC) for use authentication and delegated API access

Interactive server side (or native desktop/mobile) applications use the hybrid flow. This flow gives you the best security because the access tokens are transmitted via back-channel calls only (and gives you access to refresh tokens):

var mvcClient = new Client
{
    ClientId = "mvc",
    ClientName = "MVC Client",
    ClientUri = "http://identityserver.io",

    AllowedGrantTypes = GrantTypes.Hybrid,
    AllowOfflineAccess = true,
    ClientSecrets = { new Secret("secret".Sha256()) },

    RedirectUris =           { "http://localhost:21402/signin-oidc" },
    PostLogoutRedirectUris = { "http://localhost:21402/" },
    LogoutUri =                "http://localhost:21402/signout-oidc",

    AllowedScopes =
    {
        IdentityServerConstants.StandardScopes.OpenId,
        IdentityServerConstants.StandardScopes.Profile,
        IdentityServerConstants.StandardScopes.Email,

        "api1", "api2.read_only"
    },
};