/// <summary>
/// Called when a request to the Token endpoint arrives with a "grant_type" of "client_credentials". This occurs when a registered client
/// application wishes to acquire an "access_token" to interact with protected resources on it's own behalf, rather than on behalf of an authenticated user.
/// If the web application supports the client credentials it may assume the context.ClientId has been validated by the ValidateClientAuthentication call.
/// To issue an access token the context.Validated must be called with a new ticket containing the claims about the client application which should be associated
/// with the access token. The application should take appropriate measures to ensure that the endpoint isn't abused by malicious callers.
/// The default behavior is to reject this grant type.
/// See also http://tools.ietf.org/html/rfc6749#section-4.4.2
/// </summary>
/// <param name="context">The context of the event carries information in and results out.</param>
/// <returns>Task to enable asynchronous execution</returns>
public virtual Task GrantClientCredentials(OpenIdConnectGrantClientCredentialsContext context)
{
return OnGrantClientCredentials.Invoke(context);
}
private Task GrantClientCredentials(OpenIdConnectGrantClientCredentialsContext context)
{
// there is no identity for ClientCredentials only, so create one based on clientid
var identity = new ClaimsIdentity(new GenericIdentity(
context.ClientId, OpenIdConnectDefaults.AuthenticationType),
context.Scope.Select(x => new Claim("urn:oauth:scope", x))
);
// it must have subject claim for openid, it can be ClaimTypes.NameIdentifier
// or JwtRegisteredClaimNames.Sub
identity.AddClaim(new Claim(ClaimTypes.NameIdentifier,context.ClientId));
context.Validated(identity);
return Task.FromResult(0);
}