2024-08-08 03:53:46 -04:00

464 lines
13 KiB
Go

// Copyright (c) 2022 Gitpod GmbH. All rights reserved.
// Licensed under the GNU Affero General Public License (AGPL).
// See License.AGPL.txt in the project root for license information.
package oidc
import (
"bytes"
"context"
"crypto/rand"
"encoding/base64"
"encoding/json"
"fmt"
"io"
"net/http"
"time"
"github.com/coreos/go-oidc/v3/oidc"
goidc "github.com/coreos/go-oidc/v3/oidc"
"github.com/gitpod-io/gitpod/common-go/log"
db "github.com/gitpod-io/gitpod/components/gitpod-db/go"
"github.com/gitpod-io/gitpod/public-api-server/pkg/jws"
"github.com/golang-jwt/jwt/v5"
"github.com/google/cel-go/cel"
"github.com/google/cel-go/checker/decls"
"github.com/google/uuid"
"golang.org/x/oauth2"
"google.golang.org/grpc/codes"
"google.golang.org/grpc/status"
"gorm.io/gorm"
)
type Service struct {
dbConn *gorm.DB
cipher db.Cipher
// jwts
stateExpiry time.Duration
signerVerifier jws.SignerVerifier
sessionServiceAddress string
// TODO(at) remove by enhancing test setups
skipVerifyIdToken bool
}
type ClientConfig struct {
ID string
OrganizationID string
Issuer string
Active bool
OAuth2Config *oauth2.Config
VerifierConfig *goidc.Config
CelExpression string
UsePKCE bool
}
type StartParams struct {
State string
Nonce string
CodeVerifier string
AuthCodeURL string
}
type AuthFlowResult struct {
IDToken *goidc.IDToken `json:"idToken"`
Claims map[string]interface{} `json:"claims"`
}
func NewService(sessionServiceAddress string, dbConn *gorm.DB, cipher db.Cipher, signerVerifier jws.SignerVerifier, stateExpiry time.Duration) *Service {
return &Service{
sessionServiceAddress: sessionServiceAddress,
dbConn: dbConn,
cipher: cipher,
signerVerifier: signerVerifier,
stateExpiry: stateExpiry,
}
}
func (s *Service) getStartParams(config *ClientConfig, redirectURL string, stateParams StateParams) (*StartParams, error) {
// the `state` is supposed to be passed through unmodified by the IdP.
state, err := s.encodeStateParam(stateParams)
if err != nil {
return nil, fmt.Errorf("failed to encode state")
}
// number used once
nonce, err := randString(32)
if err != nil {
return nil, fmt.Errorf("failed to create nonce")
}
// Configuring `AuthCodeOption`s, e.g. nonce
config.OAuth2Config.RedirectURL = redirectURL
opts := []oauth2.AuthCodeOption{goidc.Nonce(nonce)}
var verifier string
if config.UsePKCE {
verifier = oauth2.GenerateVerifier()
opts = append(opts, oauth2.S256ChallengeOption(verifier))
}
authCodeURL := config.OAuth2Config.AuthCodeURL(state, opts...)
return &StartParams{
AuthCodeURL: authCodeURL,
State: state,
Nonce: nonce,
CodeVerifier: verifier,
}, nil
}
func (s *Service) encodeStateParam(state StateParams) (string, error) {
now := time.Now().UTC()
expiry := now.Add(s.stateExpiry)
token := NewStateJWT(state, now, expiry)
signed, err := s.signerVerifier.Sign(token)
if err != nil {
return "", fmt.Errorf("failed to sign jwt: %w", err)
}
return signed, nil
}
func (s *Service) decodeStateParam(encodedToken string) (StateParams, error) {
claims := &StateClaims{}
_, err := s.signerVerifier.Verify(encodedToken, claims)
if err != nil {
return StateParams{}, fmt.Errorf("failed to verify state token: %w", err)
}
return claims.StateParams, nil
}
func randString(size int) (string, error) {
b := make([]byte, size)
if _, err := io.ReadFull(rand.Reader, b); err != nil {
return "", err
}
return base64.RawURLEncoding.EncodeToString(b), nil
}
func (s *Service) getClientConfigFromStartRequest(r *http.Request) (*ClientConfig, error) {
orgSlug := r.URL.Query().Get("orgSlug")
idParam := r.URL.Query().Get("id")
// if no org slug is given, we assume the request is for the default org
if orgSlug == "" && idParam == "" {
org, err := db.GetSingleOrganizationWithActiveSSO(r.Context(), s.dbConn)
if err != nil {
return nil, fmt.Errorf("Failed to find team: %w", err)
}
orgSlug = org.Slug
}
if orgSlug != "" {
dbEntry, err := db.GetActiveOIDCClientConfigByOrgSlug(r.Context(), s.dbConn, orgSlug)
if err != nil {
return nil, fmt.Errorf("Failed to find OIDC clients: %w", err)
}
config, err := s.convertClientConfig(r.Context(), dbEntry)
if err != nil {
return nil, fmt.Errorf("Failed to find OIDC clients: %w", err)
}
return &config, nil
}
if idParam == "" {
return nil, fmt.Errorf("missing id parameter")
}
if idParam != "" {
config, err := s.getConfigById(r.Context(), idParam)
if err != nil {
return nil, err
}
return config, nil
}
return nil, fmt.Errorf("failed to find OIDC config")
}
func (s *Service) getClientConfigFromCallbackRequest(r *http.Request) (*ClientConfig, *StateParams, error) {
stateParam := r.URL.Query().Get("state")
if stateParam == "" {
return nil, nil, fmt.Errorf("missing state parameter")
}
state, err := s.decodeStateParam(stateParam)
if err != nil {
return nil, nil, fmt.Errorf("bad state param")
}
config, _ := s.getConfigById(r.Context(), state.ClientConfigID)
if config != nil {
return config, &state, nil
}
return nil, nil, fmt.Errorf("failed to find OIDC config on callback")
}
func (s *Service) activateAndVerifyClientConfig(ctx context.Context, config *ClientConfig) error {
uuid, err := uuid.Parse(config.ID)
if err != nil {
return err
}
err = db.VerifyClientConfig(ctx, s.dbConn, uuid)
if err != nil {
return err
}
return db.SetClientConfigActiviation(ctx, s.dbConn, uuid, true)
}
func (s *Service) markClientConfigAsVerified(ctx context.Context, config *ClientConfig) error {
uuid, err := uuid.Parse(config.ID)
if err != nil {
return err
}
return db.VerifyClientConfig(ctx, s.dbConn, uuid)
}
func (s *Service) getConfigById(ctx context.Context, id string) (*ClientConfig, error) {
uuid, err := uuid.Parse(id)
if err != nil {
return nil, err
}
dbEntry, err := db.GetOIDCClientConfig(ctx, s.dbConn, uuid)
if err != nil {
return nil, err
}
config, err := s.convertClientConfig(ctx, dbEntry)
if err != nil {
log.Log.WithError(err).Error("Failed to decrypt oidc client config.")
return nil, status.Errorf(codes.Internal, "Failed to decrypt OIDC client config.")
}
return &config, nil
}
func (s *Service) convertClientConfig(ctx context.Context, dbEntry db.OIDCClientConfig) (ClientConfig, error) {
spec, err := dbEntry.Data.Decrypt(s.cipher)
if err != nil {
log.Log.WithError(err).Error("Failed to decrypt oidc client config.")
return ClientConfig{}, status.Errorf(codes.Internal, "Failed to decrypt OIDC client config.")
}
provider, err := oidc.NewProvider(ctx, dbEntry.Issuer)
if err != nil {
return ClientConfig{}, err
}
return ClientConfig{
ID: dbEntry.ID.String(),
OrganizationID: dbEntry.OrganizationID.String(),
Issuer: dbEntry.Issuer,
Active: dbEntry.Active,
OAuth2Config: &oauth2.Config{
ClientID: spec.ClientID,
ClientSecret: spec.ClientSecret,
Endpoint: provider.Endpoint(),
Scopes: spec.Scopes,
},
CelExpression: spec.CelExpression,
UsePKCE: spec.UsePKCE,
VerifierConfig: &goidc.Config{
ClientID: spec.ClientID,
},
}, nil
}
type authenticateParams struct {
Config *ClientConfig
OAuth2Result *OAuth2Result
NonceCookieValue string
}
type CelExprError struct {
Msg string
Code string
}
func (e *CelExprError) Error() string {
return fmt.Sprintf("%s [%s]", e.Msg, e.Code)
}
func (s *Service) authenticate(ctx context.Context, params authenticateParams) (*AuthFlowResult, error) {
rawIDToken, ok := params.OAuth2Result.OAuth2Token.Extra("id_token").(string)
if !ok {
return nil, fmt.Errorf("id_token not found")
}
provider, err := oidc.NewProvider(ctx, params.Config.Issuer)
if err != nil {
return nil, fmt.Errorf("Failed to initialize provider.")
}
verifier := provider.Verifier(&goidc.Config{
ClientID: params.Config.OAuth2Config.ClientID,
})
idToken, err := verifier.Verify(ctx, rawIDToken)
if err != nil {
return nil, fmt.Errorf("failed to verify id_token: %w", err)
}
if idToken.Nonce != params.NonceCookieValue {
return nil, fmt.Errorf("nonce mismatch")
}
validatedClaims, err := s.validateRequiredClaims(ctx, provider, idToken)
if err != nil {
return nil, fmt.Errorf("failed to validate required claims: %w", err)
}
validatedCelExpression, err := s.verifyCelExpression(ctx, params.Config.CelExpression, validatedClaims)
if err != nil {
return nil, err
}
if !validatedCelExpression {
return nil, &CelExprError{Msg: "CEL expression did not evaluate to true", Code: "CEL:EVAL_FALSE"}
}
return &AuthFlowResult{
IDToken: idToken,
Claims: validatedClaims,
}, nil
}
func (s *Service) createSession(ctx context.Context, flowResult *AuthFlowResult, clientConfig *ClientConfig) ([]*http.Cookie, string, error) {
type CreateSessionPayload struct {
AuthFlowResult
OrganizationID string `json:"organizationId"`
ClientConfigID string `json:"oidcClientConfigId"`
}
sessionPayload := CreateSessionPayload{
AuthFlowResult: *flowResult,
OrganizationID: clientConfig.OrganizationID,
ClientConfigID: clientConfig.ID,
}
payload, err := json.Marshal(sessionPayload)
if err != nil {
return nil, "", err
}
url := fmt.Sprintf("http://%s/session", s.sessionServiceAddress)
req, err := http.NewRequestWithContext(ctx, http.MethodPost, url, bytes.NewReader(payload))
if err != nil {
return nil, "", fmt.Errorf("failed to construct session request: %w", err)
}
req.Header.Set("Content-Type", "application/json")
res, err := http.DefaultClient.Do(req)
if err != nil {
return nil, "", fmt.Errorf("failed to make request to /session endpoint: %w", err)
}
body, err := io.ReadAll(res.Body)
if err != nil {
return nil, "", err
}
message := string(body)
if res.StatusCode == http.StatusOK {
return res.Cookies(), message, nil
}
log.WithField("create-session-error", message).Error("Failed to create session (via server)")
return nil, message, fmt.Errorf("unexpected status code: %v", res.StatusCode)
}
func (s *Service) validateRequiredClaims(ctx context.Context, provider *oidc.Provider, token *goidc.IDToken) (jwt.MapClaims, error) {
if len(token.Audience) < 1 {
return nil, fmt.Errorf("audience claim is missing")
}
var claims jwt.MapClaims
err := token.Claims(&claims)
if err != nil {
return nil, fmt.Errorf("failed to unmarshal claims of ID token: %w", err)
}
requiredClaims := []string{"email", "name"}
missingClaims := []string{}
for _, claim := range requiredClaims {
if _, ok := claims[claim]; !ok {
missingClaims = append(missingClaims, claim)
}
}
if len(missingClaims) > 0 {
err = s.fillClaims(ctx, provider, claims, missingClaims)
if err != nil {
log.WithError(err).Error("failed to fill claims")
}
// continue
}
for _, claim := range requiredClaims {
if _, ok := claims[claim]; !ok {
return nil, fmt.Errorf("%s claim is missing", claim)
}
}
return claims, nil
}
func (s *Service) verifyCelExpression(ctx context.Context, celExpression string, claims jwt.MapClaims) (bool, error) {
if celExpression == "" {
return true, nil
}
env, err := cel.NewEnv(cel.Declarations(decls.NewVar("claims", decls.NewMapType(decls.String, decls.Dyn))))
if err != nil {
return false, &CelExprError{Msg: fmt.Errorf("failed to create claims env: %w", err).Error(), Code: "CEL:INVALIDATE"}
}
ast, issues := env.Compile(celExpression)
if issues != nil {
if issues.Err() != nil {
return false, &CelExprError{Msg: fmt.Errorf("failed to compile CEL Expression: %w", issues.Err()).Error(), Code: "CEL:INVALIDATE"}
}
// should not happen
log.WithField("issues", issues).Error("failed to compile CEL Expression")
return false, &CelExprError{Msg: fmt.Errorf("failed to compile CEL Expression").Error(), Code: "CEL:INVALIDATE"}
}
prg, err := env.Program(ast)
if err != nil {
log.WithError(err).Error("failed to create CEL program")
return false, &CelExprError{Msg: fmt.Errorf("failed to create CEL program").Error(), Code: "CEL:INVALIDATE"}
}
input := map[string]interface{}{
"claims": claims,
}
val, _, err := prg.ContextEval(ctx, input)
if err != nil {
return false, &CelExprError{Msg: fmt.Errorf("failed to evaluate CEL program: %w", err).Error(), Code: "CEL:EVAL_ERR"}
}
result, ok := val.Value().(bool)
if !ok {
return false, &CelExprError{Msg: fmt.Errorf("CEL Expression did not evaluate to a boolean").Error(), Code: "CEL:EVAL_NOT_BOOL"}
}
if !result {
return false, &CelExprError{Msg: fmt.Errorf("CEL Expression did not evaluate to true").Error(), Code: "CEL:EVAL_FALSE"}
}
return result, nil
}
func (s *Service) fillClaims(ctx context.Context, provider *oidc.Provider, claims jwt.MapClaims, missingClaims []string) error {
oauth2Info := GetOAuth2ResultFromContext(ctx)
if oauth2Info == nil {
return fmt.Errorf("oauth2 info not found")
}
userinfo, err := provider.UserInfo(ctx, oauth2.StaticTokenSource(oauth2Info.OAuth2Token))
if err != nil {
return fmt.Errorf("failed to get userinfo: %w", err)
}
var userinfoClaims map[string]interface{}
if err := userinfo.Claims(&userinfoClaims); err != nil {
return fmt.Errorf("failed to unmarshal userinfo claims: %w", err)
}
for _, key := range missingClaims {
switch key {
case "email":
// check userinfo definition to get more info
claims["email"] = userinfo.Email
default:
if value, ok := userinfoClaims[key]; ok {
claims[key] = value
}
}
}
return nil
}