rename models to pkg (#2005)

pkg/auth/oidc.go

@@ -0,0 +1,255 @@
+// Copyright 2020 guylewin, guy@lewin.co.il
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package auth
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/fatedier/frp/pkg/msg"
+
+	"github.com/coreos/go-oidc"
+	"github.com/vaughan0/go-ini"
+	"golang.org/x/oauth2/clientcredentials"
+)
+
+type oidcClientConfig struct {
+	// OidcClientID specifies the client ID to use to get a token in OIDC
+	// authentication if AuthenticationMethod == "oidc". By default, this value
+	// is "".
+	OidcClientID string `json:"oidc_client_id"`
+	// OidcClientSecret specifies the client secret to use to get a token in OIDC
+	// authentication if AuthenticationMethod == "oidc". By default, this value
+	// is "".
+	OidcClientSecret string `json:"oidc_client_secret"`
+	// OidcAudience specifies the audience of the token in OIDC authentication
+	//if AuthenticationMethod == "oidc". By default, this value is "".
+	OidcAudience string `json:"oidc_audience"`
+	// OidcTokenEndpointURL specifies the URL which implements OIDC Token Endpoint.
+	// It will be used to get an OIDC token if AuthenticationMethod == "oidc".
+	// By default, this value is "".
+	OidcTokenEndpointURL string `json:"oidc_token_endpoint_url"`
+}
+
+func getDefaultOidcClientConf() oidcClientConfig {
+	return oidcClientConfig{
+		OidcClientID:         "",
+		OidcClientSecret:     "",
+		OidcAudience:         "",
+		OidcTokenEndpointURL: "",
+	}
+}
+
+func unmarshalOidcClientConfFromIni(conf ini.File) oidcClientConfig {
+	var (
+		tmpStr string
+		ok     bool
+	)
+
+	cfg := getDefaultOidcClientConf()
+
+	if tmpStr, ok = conf.Get("common", "oidc_client_id"); ok {
+		cfg.OidcClientID = tmpStr
+	}
+
+	if tmpStr, ok = conf.Get("common", "oidc_client_secret"); ok {
+		cfg.OidcClientSecret = tmpStr
+	}
+
+	if tmpStr, ok = conf.Get("common", "oidc_audience"); ok {
+		cfg.OidcAudience = tmpStr
+	}
+
+	if tmpStr, ok = conf.Get("common", "oidc_token_endpoint_url"); ok {
+		cfg.OidcTokenEndpointURL = tmpStr
+	}
+
+	return cfg
+}
+
+type oidcServerConfig struct {
+	// OidcIssuer specifies the issuer to verify OIDC tokens with. This issuer
+	// will be used to load public keys to verify signature and will be compared
+	// with the issuer claim in the OIDC token. It will be used if
+	// AuthenticationMethod == "oidc". By default, this value is "".
+	OidcIssuer string `json:"oidc_issuer"`
+	// OidcAudience specifies the audience OIDC tokens should contain when validated.
+	// If this value is empty, audience ("client ID") verification will be skipped.
+	// It will be used when AuthenticationMethod == "oidc". By default, this
+	// value is "".
+	OidcAudience string `json:"oidc_audience"`
+	// OidcSkipExpiryCheck specifies whether to skip checking if the OIDC token is
+	// expired. It will be used when AuthenticationMethod == "oidc". By default, this
+	// value is false.
+	OidcSkipExpiryCheck bool `json:"oidc_skip_expiry_check"`
+	// OidcSkipIssuerCheck specifies whether to skip checking if the OIDC token's
+	// issuer claim matches the issuer specified in OidcIssuer. It will be used when
+	// AuthenticationMethod == "oidc". By default, this value is false.
+	OidcSkipIssuerCheck bool `json:"oidc_skip_issuer_check"`
+}
+
+func getDefaultOidcServerConf() oidcServerConfig {
+	return oidcServerConfig{
+		OidcIssuer:          "",
+		OidcAudience:        "",
+		OidcSkipExpiryCheck: false,
+		OidcSkipIssuerCheck: false,
+	}
+}
+
+func unmarshalOidcServerConfFromIni(conf ini.File) oidcServerConfig {
+	var (
+		tmpStr string
+		ok     bool
+	)
+
+	cfg := getDefaultOidcServerConf()
+
+	if tmpStr, ok = conf.Get("common", "oidc_issuer"); ok {
+		cfg.OidcIssuer = tmpStr
+	}
+
+	if tmpStr, ok = conf.Get("common", "oidc_audience"); ok {
+		cfg.OidcAudience = tmpStr
+	}
+
+	if tmpStr, ok = conf.Get("common", "oidc_skip_expiry_check"); ok && tmpStr == "true" {
+		cfg.OidcSkipExpiryCheck = true
+	} else {
+		cfg.OidcSkipExpiryCheck = false
+	}
+
+	if tmpStr, ok = conf.Get("common", "oidc_skip_issuer_check"); ok && tmpStr == "true" {
+		cfg.OidcSkipIssuerCheck = true
+	} else {
+		cfg.OidcSkipIssuerCheck = false
+	}
+
+	return cfg
+}
+
+type OidcAuthProvider struct {
+	baseConfig
+
+	tokenGenerator *clientcredentials.Config
+}
+
+func NewOidcAuthSetter(baseCfg baseConfig, cfg oidcClientConfig) *OidcAuthProvider {
+	tokenGenerator := &clientcredentials.Config{
+		ClientID:     cfg.OidcClientID,
+		ClientSecret: cfg.OidcClientSecret,
+		Scopes:       []string{cfg.OidcAudience},
+		TokenURL:     cfg.OidcTokenEndpointURL,
+	}
+
+	return &OidcAuthProvider{
+		baseConfig:     baseCfg,
+		tokenGenerator: tokenGenerator,
+	}
+}
+
+func (auth *OidcAuthProvider) generateAccessToken() (accessToken string, err error) {
+	tokenObj, err := auth.tokenGenerator.Token(context.Background())
+	if err != nil {
+		return "", fmt.Errorf("couldn't generate OIDC token for login: %v", err)
+	}
+	return tokenObj.AccessToken, nil
+}
+
+func (auth *OidcAuthProvider) SetLogin(loginMsg *msg.Login) (err error) {
+	loginMsg.PrivilegeKey, err = auth.generateAccessToken()
+	return err
+}
+
+func (auth *OidcAuthProvider) SetPing(pingMsg *msg.Ping) (err error) {
+	if !auth.AuthenticateHeartBeats {
+		return nil
+	}
+
+	pingMsg.PrivilegeKey, err = auth.generateAccessToken()
+	return err
+}
+
+func (auth *OidcAuthProvider) SetNewWorkConn(newWorkConnMsg *msg.NewWorkConn) (err error) {
+	if !auth.AuthenticateNewWorkConns {
+		return nil
+	}
+
+	newWorkConnMsg.PrivilegeKey, err = auth.generateAccessToken()
+	return err
+}
+
+type OidcAuthConsumer struct {
+	baseConfig
+
+	verifier         *oidc.IDTokenVerifier
+	subjectFromLogin string
+}
+
+func NewOidcAuthVerifier(baseCfg baseConfig, cfg oidcServerConfig) *OidcAuthConsumer {
+	provider, err := oidc.NewProvider(context.Background(), cfg.OidcIssuer)
+	if err != nil {
+		panic(err)
+	}
+	verifierConf := oidc.Config{
+		ClientID:          cfg.OidcAudience,
+		SkipClientIDCheck: cfg.OidcAudience == "",
+		SkipExpiryCheck:   cfg.OidcSkipExpiryCheck,
+		SkipIssuerCheck:   cfg.OidcSkipIssuerCheck,
+	}
+	return &OidcAuthConsumer{
+		baseConfig: baseCfg,
+		verifier:   provider.Verifier(&verifierConf),
+	}
+}
+
+func (auth *OidcAuthConsumer) VerifyLogin(loginMsg *msg.Login) (err error) {
+	token, err := auth.verifier.Verify(context.Background(), loginMsg.PrivilegeKey)
+	if err != nil {
+		return fmt.Errorf("invalid OIDC token in login: %v", err)
+	}
+	auth.subjectFromLogin = token.Subject
+	return nil
+}
+
+func (auth *OidcAuthConsumer) verifyPostLoginToken(privilegeKey string) (err error) {
+	token, err := auth.verifier.Verify(context.Background(), privilegeKey)
+	if err != nil {
+		return fmt.Errorf("invalid OIDC token in ping: %v", err)
+	}
+	if token.Subject != auth.subjectFromLogin {
+		return fmt.Errorf("received different OIDC subject in login and ping. "+
+			"original subject: %s, "+
+			"new subject: %s",
+			auth.subjectFromLogin, token.Subject)
+	}
+	return nil
+}
+
+func (auth *OidcAuthConsumer) VerifyPing(pingMsg *msg.Ping) (err error) {
+	if !auth.AuthenticateHeartBeats {
+		return nil
+	}
+
+	return auth.verifyPostLoginToken(pingMsg.PrivilegeKey)
+}
+
+func (auth *OidcAuthConsumer) VerifyNewWorkConn(newWorkConnMsg *msg.NewWorkConn) (err error) {
+	if !auth.AuthenticateNewWorkConns {
+		return nil
+	}
+
+	return auth.verifyPostLoginToken(newWorkConnMsg.PrivilegeKey)
+}