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dex/server/server.go
2018-12-13 11:50:34 +01:00

527 lines
15 KiB
Go

package server
import (
"context"
"encoding/json"
"errors"
"fmt"
"net/http"
"net/url"
"path"
"strconv"
"strings"
"sync"
"sync/atomic"
"time"
"golang.org/x/crypto/bcrypt"
"github.com/felixge/httpsnoop"
"github.com/gorilla/handlers"
"github.com/gorilla/mux"
"github.com/prometheus/client_golang/prometheus"
"github.com/sirupsen/logrus"
"github.com/dexidp/dex/connector"
"github.com/dexidp/dex/connector/authproxy"
"github.com/dexidp/dex/connector/bitbucketcloud"
"github.com/dexidp/dex/connector/github"
"github.com/dexidp/dex/connector/gitlab"
"github.com/dexidp/dex/connector/ldap"
"github.com/dexidp/dex/connector/linkedin"
"github.com/dexidp/dex/connector/microsoft"
"github.com/dexidp/dex/connector/mock"
"github.com/dexidp/dex/connector/oidc"
"github.com/dexidp/dex/connector/saml"
"github.com/dexidp/dex/storage"
)
// LocalConnector is the local passwordDB connector which is an internal
// connector maintained by the server.
const LocalConnector = "local"
// Connector is a connector with resource version metadata.
type Connector struct {
ResourceVersion string
Connector connector.Connector
}
// Config holds the server's configuration options.
//
// Multiple servers using the same storage are expected to be configured identically.
type Config struct {
Issuer string
// The backing persistence layer.
Storage storage.Storage
// Valid values are "code" to enable the code flow and "token" to enable the implicit
// flow. If no response types are supplied this value defaults to "code".
SupportedResponseTypes []string
// List of allowed origins for CORS requests on discovery, token and keys endpoint.
// If none are indicated, CORS requests are disabled. Passing in "*" will allow any
// domain.
AllowedOrigins []string
// If enabled, the server won't prompt the user to approve authorization requests.
// Logging in implies approval.
SkipApprovalScreen bool
RotateKeysAfter time.Duration // Defaults to 6 hours.
IDTokensValidFor time.Duration // Defaults to 24 hours
AuthRequestsValidFor time.Duration // Defaults to 24 hours
GCFrequency time.Duration // Defaults to 5 minutes
// If specified, the server will use this function for determining time.
Now func() time.Time
Web WebConfig
Logger logrus.FieldLogger
PrometheusRegistry *prometheus.Registry
}
// WebConfig holds the server's frontend templates and asset configuration.
//
// These are currently very custom to CoreOS and it's not recommended that
// outside users attempt to customize these.
type WebConfig struct {
// A filepath to web static.
//
// It is expected to contain the following directories:
//
// * static - Static static served at "( issuer URL )/static".
// * templates - HTML templates controlled by dex.
// * themes/(theme) - Static static served at "( issuer URL )/theme".
//
Dir string
// Defaults to "( issuer URL )/theme/logo.png"
LogoURL string
// Defaults to "dex"
Issuer string
// Defaults to "coreos"
Theme string
}
func value(val, defaultValue time.Duration) time.Duration {
if val == 0 {
return defaultValue
}
return val
}
// Server is the top level object.
type Server struct {
issuerURL url.URL
// mutex for the connectors map.
mu sync.Mutex
// Map of connector IDs to connectors.
connectors map[string]Connector
storage storage.Storage
mux http.Handler
templates *templates
// If enabled, don't prompt user for approval after logging in through connector.
skipApproval bool
supportedResponseTypes map[string]bool
now func() time.Time
idTokensValidFor time.Duration
authRequestsValidFor time.Duration
logger logrus.FieldLogger
}
// NewServer constructs a server from the provided config.
func NewServer(ctx context.Context, c Config) (*Server, error) {
return newServer(ctx, c, defaultRotationStrategy(
value(c.RotateKeysAfter, 6*time.Hour),
value(c.IDTokensValidFor, 24*time.Hour),
))
}
func newServer(ctx context.Context, c Config, rotationStrategy rotationStrategy) (*Server, error) {
issuerURL, err := url.Parse(c.Issuer)
if err != nil {
return nil, fmt.Errorf("server: can't parse issuer URL")
}
if c.Storage == nil {
return nil, errors.New("server: storage cannot be nil")
}
if len(c.SupportedResponseTypes) == 0 {
c.SupportedResponseTypes = []string{responseTypeCode}
}
supported := make(map[string]bool)
for _, respType := range c.SupportedResponseTypes {
switch respType {
case responseTypeCode, responseTypeIDToken, responseTypeToken:
default:
return nil, fmt.Errorf("unsupported response_type %q", respType)
}
supported[respType] = true
}
web := webConfig{
dir: c.Web.Dir,
logoURL: c.Web.LogoURL,
issuerURL: c.Issuer,
issuer: c.Web.Issuer,
theme: c.Web.Theme,
}
static, theme, tmpls, err := loadWebConfig(web)
if err != nil {
return nil, fmt.Errorf("server: failed to load web static: %v", err)
}
now := c.Now
if now == nil {
now = time.Now
}
s := &Server{
issuerURL: *issuerURL,
connectors: make(map[string]Connector),
storage: newKeyCacher(c.Storage, now),
supportedResponseTypes: supported,
idTokensValidFor: value(c.IDTokensValidFor, 24*time.Hour),
authRequestsValidFor: value(c.AuthRequestsValidFor, 24*time.Hour),
skipApproval: c.SkipApprovalScreen,
now: now,
templates: tmpls,
logger: c.Logger,
}
// Retrieves connector objects in backend storage. This list includes the static connectors
// defined in the ConfigMap and dynamic connectors retrieved from the storage.
storageConnectors, err := c.Storage.ListConnectors()
if err != nil {
return nil, fmt.Errorf("server: failed to list connector objects from storage: %v", err)
}
if len(storageConnectors) == 0 && len(s.connectors) == 0 {
return nil, errors.New("server: no connectors specified")
}
for _, conn := range storageConnectors {
if _, err := s.OpenConnector(conn); err != nil {
return nil, fmt.Errorf("server: Failed to open connector %s: %v", conn.ID, err)
}
}
requestCounter := prometheus.NewCounterVec(prometheus.CounterOpts{
Name: "http_requests_total",
Help: "Count of all HTTP requests.",
}, []string{"handler", "code", "method"})
err = c.PrometheusRegistry.Register(requestCounter)
if err != nil {
return nil, fmt.Errorf("server: Failed to register Prometheus HTTP metrics: %v", err)
}
instrumentHandlerCounter := func(handlerName string, handler http.Handler) http.HandlerFunc {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
m := httpsnoop.CaptureMetrics(handler, w, r)
requestCounter.With(prometheus.Labels{"handler": handlerName, "code": strconv.Itoa(m.Code), "method": r.Method}).Inc()
})
}
r := mux.NewRouter()
handleFunc := func(p string, h http.HandlerFunc) {
r.HandleFunc(path.Join(issuerURL.Path, p), instrumentHandlerCounter(p, h))
}
handlePrefix := func(p string, h http.Handler) {
prefix := path.Join(issuerURL.Path, p)
r.PathPrefix(prefix).Handler(http.StripPrefix(prefix, h))
}
handleWithCORS := func(p string, h http.HandlerFunc) {
var handler http.Handler = h
if len(c.AllowedOrigins) > 0 {
corsOption := handlers.AllowedOrigins(c.AllowedOrigins)
handler = handlers.CORS(corsOption)(handler)
}
r.Handle(path.Join(issuerURL.Path, p), handler)
}
r.NotFoundHandler = http.HandlerFunc(http.NotFound)
discoveryHandler, err := s.discoveryHandler()
if err != nil {
return nil, err
}
handleWithCORS("/.well-known/openid-configuration", discoveryHandler)
// TODO(ericchiang): rate limit certain paths based on IP.
handleWithCORS("/token", s.handleToken)
handleWithCORS("/keys", s.handlePublicKeys)
handleFunc("/auth", s.handleAuthorization)
handleFunc("/auth/{connector}", s.handleConnectorLogin)
r.HandleFunc(path.Join(issuerURL.Path, "/callback"), func(w http.ResponseWriter, r *http.Request) {
// Strip the X-Remote-* headers to prevent security issues on
// misconfigured authproxy connector setups.
for key := range r.Header {
if strings.HasPrefix(strings.ToLower(key), "x-remote-") {
r.Header.Del(key)
}
}
s.handleConnectorCallback(w, r)
})
// For easier connector-specific web server configuration, e.g. for the
// "authproxy" connector.
handleFunc("/callback/{connector}", s.handleConnectorCallback)
handleFunc("/approval", s.handleApproval)
handleFunc("/healthz", s.handleHealth)
handlePrefix("/static", static)
handlePrefix("/theme", theme)
s.mux = r
s.startKeyRotation(ctx, rotationStrategy, now)
s.startGarbageCollection(ctx, value(c.GCFrequency, 5*time.Minute), now)
return s, nil
}
func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
s.mux.ServeHTTP(w, r)
}
func (s *Server) absPath(pathItems ...string) string {
paths := make([]string, len(pathItems)+1)
paths[0] = s.issuerURL.Path
copy(paths[1:], pathItems)
return path.Join(paths...)
}
func (s *Server) absURL(pathItems ...string) string {
u := s.issuerURL
u.Path = s.absPath(pathItems...)
return u.String()
}
func newPasswordDB(s storage.Storage) interface {
connector.Connector
connector.PasswordConnector
} {
return passwordDB{s}
}
type passwordDB struct {
s storage.Storage
}
func (db passwordDB) Login(ctx context.Context, s connector.Scopes, email, password string) (connector.Identity, bool, error) {
p, err := db.s.GetPassword(email)
if err != nil {
if err != storage.ErrNotFound {
return connector.Identity{}, false, fmt.Errorf("get password: %v", err)
}
return connector.Identity{}, false, nil
}
// This check prevents dex users from logging in using static passwords
// configured with hash costs that are too high or low.
if err := checkCost(p.Hash); err != nil {
return connector.Identity{}, false, err
}
if err := bcrypt.CompareHashAndPassword(p.Hash, []byte(password)); err != nil {
return connector.Identity{}, false, nil
}
return connector.Identity{
UserID: p.UserID,
Username: p.Username,
Email: p.Email,
EmailVerified: true,
}, true, nil
}
func (db passwordDB) Refresh(ctx context.Context, s connector.Scopes, identity connector.Identity) (connector.Identity, error) {
// If the user has been deleted, the refresh token will be rejected.
p, err := db.s.GetPassword(identity.Email)
if err != nil {
if err == storage.ErrNotFound {
return connector.Identity{}, errors.New("user not found")
}
return connector.Identity{}, fmt.Errorf("get password: %v", err)
}
// User removed but a new user with the same email exists.
if p.UserID != identity.UserID {
return connector.Identity{}, errors.New("user not found")
}
// If a user has updated their username, that will be reflected in the
// refreshed token.
//
// No other fields are expected to be refreshable as email is effectively used
// as an ID and this implementation doesn't deal with groups.
identity.Username = p.Username
return identity, nil
}
func (db passwordDB) Prompt() string {
return "Email Address"
}
// newKeyCacher returns a storage which caches keys so long as the next
func newKeyCacher(s storage.Storage, now func() time.Time) storage.Storage {
if now == nil {
now = time.Now
}
return &keyCacher{Storage: s, now: now}
}
type keyCacher struct {
storage.Storage
now func() time.Time
keys atomic.Value // Always holds nil or type *storage.Keys.
}
func (k *keyCacher) GetKeys() (storage.Keys, error) {
keys, ok := k.keys.Load().(*storage.Keys)
if ok && keys != nil && k.now().Before(keys.NextRotation) {
return *keys, nil
}
storageKeys, err := k.Storage.GetKeys()
if err != nil {
return storageKeys, err
}
if k.now().Before(storageKeys.NextRotation) {
k.keys.Store(&storageKeys)
}
return storageKeys, nil
}
func (s *Server) startGarbageCollection(ctx context.Context, frequency time.Duration, now func() time.Time) {
go func() {
for {
select {
case <-ctx.Done():
return
case <-time.After(frequency):
if r, err := s.storage.GarbageCollect(now()); err != nil {
s.logger.Errorf("garbage collection failed: %v", err)
} else if r.AuthRequests > 0 || r.AuthCodes > 0 {
s.logger.Infof("garbage collection run, delete auth requests=%d, auth codes=%d", r.AuthRequests, r.AuthCodes)
}
}
}
}()
return
}
// ConnectorConfig is a configuration that can open a connector.
type ConnectorConfig interface {
Open(id string, logger logrus.FieldLogger) (connector.Connector, error)
}
// ConnectorsConfig variable provides an easy way to return a config struct
// depending on the connector type.
var ConnectorsConfig = map[string]func() ConnectorConfig{
"mockCallback": func() ConnectorConfig { return new(mock.CallbackConfig) },
"mockPassword": func() ConnectorConfig { return new(mock.PasswordConfig) },
"ldap": func() ConnectorConfig { return new(ldap.Config) },
"github": func() ConnectorConfig { return new(github.Config) },
"gitlab": func() ConnectorConfig { return new(gitlab.Config) },
"oidc": func() ConnectorConfig { return new(oidc.Config) },
"saml": func() ConnectorConfig { return new(saml.Config) },
"authproxy": func() ConnectorConfig { return new(authproxy.Config) },
"linkedin": func() ConnectorConfig { return new(linkedin.Config) },
"microsoft": func() ConnectorConfig { return new(microsoft.Config) },
"bitbucket-cloud": func() ConnectorConfig { return new(bitbucketcloud.Config) },
// Keep around for backwards compatibility.
"samlExperimental": func() ConnectorConfig { return new(saml.Config) },
}
// openConnector will parse the connector config and open the connector.
func openConnector(logger logrus.FieldLogger, conn storage.Connector) (connector.Connector, error) {
var c connector.Connector
f, ok := ConnectorsConfig[conn.Type]
if !ok {
return c, fmt.Errorf("unknown connector type %q", conn.Type)
}
connConfig := f()
if len(conn.Config) != 0 {
data := []byte(string(conn.Config))
if err := json.Unmarshal(data, connConfig); err != nil {
return c, fmt.Errorf("parse connector config: %v", err)
}
}
c, err := connConfig.Open(conn.ID, logger)
if err != nil {
return c, fmt.Errorf("failed to create connector %s: %v", conn.ID, err)
}
return c, nil
}
// OpenConnector updates server connector map with specified connector object.
func (s *Server) OpenConnector(conn storage.Connector) (Connector, error) {
var c connector.Connector
if conn.Type == LocalConnector {
c = newPasswordDB(s.storage)
} else {
var err error
c, err = openConnector(s.logger.WithField("connector", conn.Name), conn)
if err != nil {
return Connector{}, fmt.Errorf("failed to open connector: %v", err)
}
}
connector := Connector{
ResourceVersion: conn.ResourceVersion,
Connector: c,
}
s.mu.Lock()
s.connectors[conn.ID] = connector
s.mu.Unlock()
return connector, nil
}
// getConnector retrieves the connector object with the given id from the storage
// and updates the connector list for server if necessary.
func (s *Server) getConnector(id string) (Connector, error) {
storageConnector, err := s.storage.GetConnector(id)
if err != nil {
return Connector{}, fmt.Errorf("failed to get connector object from storage: %v", err)
}
var conn Connector
var ok bool
s.mu.Lock()
conn, ok = s.connectors[id]
s.mu.Unlock()
if !ok || storageConnector.ResourceVersion != conn.ResourceVersion {
// Connector object does not exist in server connectors map or
// has been updated in the storage. Need to get latest.
conn, err := s.OpenConnector(storageConnector)
if err != nil {
return Connector{}, fmt.Errorf("failed to open connector: %v", err)
}
return conn, nil
}
return conn, nil
}