inching forward with oidc idp

internal/oidc/oidc.go

@@ -0,0 +1,76 @@
+package oidc
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/coreos/go-oidc/v3/oidc"
+	"github.com/superseriousbusiness/gotosocial/internal/config"
+	"golang.org/x/oauth2"
+)
+
+const (
+	// CallbackPath is the API path for receiving callback tokens from external OIDC providers
+	CallbackPath = "/auth/callback"
+	profileScope = "profile"
+	emailScope   = "email"
+	groupsScope  = "groups"
+)
+
+type IDP interface {
+}
+
+type idp struct {
+	oauth2Config    oauth2.Config
+	provider        *oidc.Provider
+	idTokenVerifier *oidc.IDTokenVerifier
+}
+
+func NewIDP(config *config.Config) (IDP, error) {
+
+	// oidc isn't enabled so we don't need to do anything
+	if !config.OIDCConfig.Enabled {
+		return nil, nil
+	}
+
+	// validate config fields
+	if config.OIDCConfig.IDPID == "" {
+		return nil, fmt.Errorf("not set: IDPID")
+	}
+
+	if config.OIDCConfig.IDPName == "" {
+		return nil, fmt.Errorf("not set: IDPName")
+	}
+
+	aaaaaaaaaaaaaaaaaaaaaaaaaaaa
+
+
+	provider, err := oidc.NewProvider(context.Background(), config.OIDCConfig.Issuer)
+	if err != nil {
+		return nil, err
+	}
+
+	oauth2Config := oauth2.Config{
+		// client_id and client_secret of the client.
+		ClientID:     config.OIDCConfig.ClientID,
+		ClientSecret: config.OIDCConfig.ClientSecret,
+
+		// The redirectURL.
+		RedirectURL: fmt.Sprintf("%s://%s%s", config.Protocol, config.Host, CallbackPath),
+
+		// Discovery returns the OAuth2 endpoints.
+		Endpoint: provider.Endpoint(),
+
+		// "openid" is a required scope for OpenID Connect flows.
+		//
+		// Other scopes, such as "groups" can be requested.
+		Scopes: config.OIDCConfig.Scopes,
+	}
+
+	idTokenVerifier := provider.Verifier(&oidc.Config{ClientID: config.OIDCConfig.ClientID})
+
+	return &idp{
+		oauth2Config:    oauth2Config,
+		idTokenVerifier: idTokenVerifier,
+	}, nil
+}