sftpgo/httpd/middleware.go
Nicola Murino 8a4c21b64a
add builtin two-factor auth support
The builtin two-factor authentication is based on time-based one time
passwords (RFC 6238) which works with Authy, Google Authenticator and
other compatible apps.
2021-09-04 12:11:04 +02:00

458 lines
14 KiB
Go

package httpd
import (
"errors"
"fmt"
"net/http"
"runtime/debug"
"strings"
"time"
"github.com/go-chi/chi/v5/middleware"
"github.com/go-chi/jwtauth/v5"
"github.com/lestrrat-go/jwx/jwt"
"github.com/rs/xid"
"github.com/drakkan/sftpgo/v2/common"
"github.com/drakkan/sftpgo/v2/dataprovider"
"github.com/drakkan/sftpgo/v2/logger"
"github.com/drakkan/sftpgo/v2/sdk"
"github.com/drakkan/sftpgo/v2/util"
)
var (
forwardedProtoKey = &contextKey{"forwarded proto"}
errInvalidToken = errors.New("invalid JWT token")
)
type contextKey struct {
name string
}
func (k *contextKey) String() string {
return "context value " + k.name
}
func validateJWTToken(w http.ResponseWriter, r *http.Request, audience tokenAudience) error {
token, _, err := jwtauth.FromContext(r.Context())
var redirectPath string
if audience == tokenAudienceWebAdmin {
redirectPath = webLoginPath
} else {
redirectPath = webClientLoginPath
}
isAPIToken := (audience == tokenAudienceAPI || audience == tokenAudienceAPIUser)
if err != nil || token == nil {
logger.Debug(logSender, "", "error getting jwt token: %v", err)
if isAPIToken {
sendAPIResponse(w, r, err, http.StatusText(http.StatusUnauthorized), http.StatusUnauthorized)
} else {
http.Redirect(w, r, redirectPath, http.StatusFound)
}
return errInvalidToken
}
err = jwt.Validate(token)
if err != nil {
logger.Debug(logSender, "", "error validating jwt token: %v", err)
if isAPIToken {
sendAPIResponse(w, r, err, http.StatusText(http.StatusUnauthorized), http.StatusUnauthorized)
} else {
http.Redirect(w, r, redirectPath, http.StatusFound)
}
return errInvalidToken
}
if isTokenInvalidated(r) {
logger.Debug(logSender, "", "the token has been invalidated")
if isAPIToken {
sendAPIResponse(w, r, nil, "Your token is no longer valid", http.StatusUnauthorized)
} else {
http.Redirect(w, r, redirectPath, http.StatusFound)
}
return errInvalidToken
}
// a user with a partial token will be always redirected to the appropriate two factor auth page
if err := checkPartialAuth(w, r, audience, token.Audience()); err != nil {
return err
}
if !util.IsStringInSlice(audience, token.Audience()) {
logger.Debug(logSender, "", "the token is not valid for audience %#v", audience)
if isAPIToken {
sendAPIResponse(w, r, nil, "Your token audience is not valid", http.StatusUnauthorized)
} else {
http.Redirect(w, r, redirectPath, http.StatusFound)
}
return errInvalidToken
}
return nil
}
func validateJWTPartialToken(w http.ResponseWriter, r *http.Request, audience tokenAudience) error {
token, _, err := jwtauth.FromContext(r.Context())
var notFoundFunc func(w http.ResponseWriter, r *http.Request, err error)
if audience == tokenAudienceWebAdminPartial {
notFoundFunc = renderNotFoundPage
} else {
notFoundFunc = renderClientNotFoundPage
}
if err != nil || token == nil || jwt.Validate(token) != nil {
notFoundFunc(w, r, nil)
return errInvalidToken
}
if isTokenInvalidated(r) {
notFoundFunc(w, r, nil)
return errInvalidToken
}
if !util.IsStringInSlice(audience, token.Audience()) {
logger.Debug(logSender, "", "the token is not valid for audience %#v", audience)
notFoundFunc(w, r, nil)
return errInvalidToken
}
return nil
}
func jwtAuthenticatorPartial(audience tokenAudience) func(next http.Handler) http.Handler {
return func(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
if err := validateJWTPartialToken(w, r, audience); err != nil {
return
}
// Token is authenticated, pass it through
next.ServeHTTP(w, r)
})
}
}
func jwtAuthenticatorAPI(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
if err := validateJWTToken(w, r, tokenAudienceAPI); err != nil {
return
}
// Token is authenticated, pass it through
next.ServeHTTP(w, r)
})
}
func jwtAuthenticatorAPIUser(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
if err := validateJWTToken(w, r, tokenAudienceAPIUser); err != nil {
return
}
// Token is authenticated, pass it through
next.ServeHTTP(w, r)
})
}
func jwtAuthenticatorWebAdmin(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
if err := validateJWTToken(w, r, tokenAudienceWebAdmin); err != nil {
return
}
// Token is authenticated, pass it through
next.ServeHTTP(w, r)
})
}
func jwtAuthenticatorWebClient(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
if err := validateJWTToken(w, r, tokenAudienceWebClient); err != nil {
return
}
// Token is authenticated, pass it through
next.ServeHTTP(w, r)
})
}
func checkHTTPUserPerm(perm string) func(next http.Handler) http.Handler {
return func(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
_, claims, err := jwtauth.FromContext(r.Context())
if err != nil {
if isWebRequest(r) {
renderClientBadRequestPage(w, r, err)
} else {
sendAPIResponse(w, r, err, http.StatusText(http.StatusBadRequest), http.StatusBadRequest)
}
return
}
tokenClaims := jwtTokenClaims{}
tokenClaims.Decode(claims)
// for web client perms are negated and not granted
if tokenClaims.hasPerm(perm) {
if isWebRequest(r) {
renderClientForbiddenPage(w, r, "You don't have permission for this action")
} else {
sendAPIResponse(w, r, nil, http.StatusText(http.StatusForbidden), http.StatusForbidden)
}
return
}
next.ServeHTTP(w, r)
})
}
}
func checkPerm(perm string) func(next http.Handler) http.Handler {
return func(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
_, claims, err := jwtauth.FromContext(r.Context())
if err != nil {
if isWebRequest(r) {
renderBadRequestPage(w, r, err)
} else {
sendAPIResponse(w, r, err, http.StatusText(http.StatusBadRequest), http.StatusBadRequest)
}
return
}
tokenClaims := jwtTokenClaims{}
tokenClaims.Decode(claims)
if !tokenClaims.hasPerm(perm) {
if isWebRequest(r) {
renderForbiddenPage(w, r, "You don't have permission for this action")
} else {
sendAPIResponse(w, r, nil, http.StatusText(http.StatusForbidden), http.StatusForbidden)
}
return
}
next.ServeHTTP(w, r)
})
}
}
func verifyCSRFHeader(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
tokenString := r.Header.Get(csrfHeaderToken)
token, err := jwtauth.VerifyToken(csrfTokenAuth, tokenString)
if err != nil || token == nil {
logger.Debug(logSender, "", "error validating CSRF header: %v", err)
sendAPIResponse(w, r, err, "Invalid token", http.StatusForbidden)
return
}
if !util.IsStringInSlice(tokenAudienceCSRF, token.Audience()) {
logger.Debug(logSender, "", "error validating CSRF header audience")
sendAPIResponse(w, r, errors.New("the token is not valid"), "", http.StatusForbidden)
return
}
next.ServeHTTP(w, r)
})
}
func checkAPIKeyAuth(tokenAuth *jwtauth.JWTAuth, scope dataprovider.APIKeyScope) func(next http.Handler) http.Handler {
return func(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
apiKey := r.Header.Get("X-SFTPGO-API-KEY")
if apiKey == "" {
next.ServeHTTP(w, r)
return
}
keyParams := strings.SplitN(apiKey, ".", 3)
if len(keyParams) < 2 {
logger.Debug(logSender, "", "invalid api key %#v", apiKey)
sendAPIResponse(w, r, errors.New("the provided api key is not valid"), "", http.StatusBadRequest)
return
}
keyID := keyParams[0]
key := keyParams[1]
apiUser := ""
if len(keyParams) > 2 {
apiUser = keyParams[2]
}
k, err := dataprovider.APIKeyExists(keyID)
if err != nil {
logger.Debug(logSender, "invalid api key %#v: %v", apiKey, err)
sendAPIResponse(w, r, errors.New("the provided api key is not valid"), "", http.StatusBadRequest)
return
}
if err := k.Authenticate(key); err != nil {
logger.Debug(logSender, "unable to authenticate api key %#v: %v", apiKey, err)
sendAPIResponse(w, r, fmt.Errorf("the provided api key cannot be authenticated"), "", http.StatusUnauthorized)
return
}
if scope == dataprovider.APIKeyScopeAdmin {
if k.Admin != "" {
apiUser = k.Admin
}
if err := authenticateAdminWithAPIKey(apiUser, keyID, tokenAuth, r); err != nil {
logger.Debug(logSender, "", "unable to authenticate admin %#v associated with api key %#v: %v",
apiUser, apiKey, err)
sendAPIResponse(w, r, fmt.Errorf("the admin associated with the provided api key cannot be authenticated"),
"", http.StatusUnauthorized)
return
}
} else {
if k.User != "" {
apiUser = k.User
}
if err := authenticateUserWithAPIKey(apiUser, keyID, tokenAuth, r); err != nil {
logger.Debug(logSender, "", "unable to authenticate user %#v associated with api key %#v: %v",
apiUser, apiKey, err)
code := http.StatusUnauthorized
if errors.Is(err, common.ErrInternalFailure) {
code = http.StatusInternalServerError
}
sendAPIResponse(w, r, errors.New("the user associated with the provided api key cannot be authenticated"),
"", code)
return
}
}
dataprovider.UpdateAPIKeyLastUse(&k) //nolint:errcheck
next.ServeHTTP(w, r)
})
}
}
func forbidAPIKeyAuthentication(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
claims, err := getTokenClaims(r)
if err != nil || claims.Username == "" {
sendAPIResponse(w, r, err, "Invalid token claims", http.StatusBadRequest)
return
}
if claims.APIKeyID != "" {
sendAPIResponse(w, r, nil, "API key authentication is not allowed", http.StatusForbidden)
return
}
next.ServeHTTP(w, r)
})
}
func recoverer(next http.Handler) http.Handler {
fn := func(w http.ResponseWriter, r *http.Request) {
defer func() {
if rvr := recover(); rvr != nil {
if rvr == http.ErrAbortHandler {
panic(rvr)
}
logEntry := middleware.GetLogEntry(r)
if logEntry != nil {
logEntry.Panic(rvr, debug.Stack())
} else {
middleware.PrintPrettyStack(rvr)
}
w.WriteHeader(http.StatusInternalServerError)
}
}()
next.ServeHTTP(w, r)
}
return http.HandlerFunc(fn)
}
func authenticateAdminWithAPIKey(username, keyID string, tokenAuth *jwtauth.JWTAuth, r *http.Request) error {
if username == "" {
return errors.New("the provided key is not associated with any admin and no username was provided")
}
admin, err := dataprovider.AdminExists(username)
if err != nil {
return err
}
if !admin.Filters.AllowAPIKeyAuth {
return fmt.Errorf("API key authentication disabled for admin %#v", admin.Username)
}
if err := admin.CanLogin(util.GetIPFromRemoteAddress(r.RemoteAddr)); err != nil {
return err
}
c := jwtTokenClaims{
Username: admin.Username,
Permissions: admin.Permissions,
Signature: admin.GetSignature(),
APIKeyID: keyID,
}
resp, err := c.createTokenResponse(tokenAuth, tokenAudienceAPI)
if err != nil {
return err
}
r.Header.Set("Authorization", fmt.Sprintf("Bearer %v", resp["access_token"]))
dataprovider.UpdateAdminLastLogin(&admin)
return nil
}
func authenticateUserWithAPIKey(username, keyID string, tokenAuth *jwtauth.JWTAuth, r *http.Request) error {
ipAddr := util.GetIPFromRemoteAddress(r.RemoteAddr)
if username == "" {
err := errors.New("the provided key is not associated with any user and no username was provided")
updateLoginMetrics(&dataprovider.User{BaseUser: sdk.BaseUser{Username: username}}, ipAddr, err)
return err
}
if err := common.Config.ExecutePostConnectHook(ipAddr, common.ProtocolHTTP); err != nil {
return err
}
user, err := dataprovider.UserExists(username)
if err != nil {
updateLoginMetrics(&dataprovider.User{BaseUser: sdk.BaseUser{Username: username}}, ipAddr, err)
return err
}
if !user.Filters.AllowAPIKeyAuth {
err := fmt.Errorf("API key authentication disabled for user %#v", user.Username)
updateLoginMetrics(&user, ipAddr, err)
return err
}
if err := user.CheckLoginConditions(); err != nil {
updateLoginMetrics(&user, ipAddr, err)
return err
}
connectionID := fmt.Sprintf("%v_%v", common.ProtocolHTTP, xid.New().String())
if err := checkHTTPClientUser(&user, r, connectionID); err != nil {
updateLoginMetrics(&user, ipAddr, err)
return err
}
lastLogin := util.GetTimeFromMsecSinceEpoch(user.LastLogin)
diff := -time.Until(lastLogin)
if diff < 0 || diff > 10*time.Minute {
defer user.CloseFs() //nolint:errcheck
err = user.CheckFsRoot(connectionID)
if err != nil {
updateLoginMetrics(&user, ipAddr, common.ErrInternalFailure)
return common.ErrInternalFailure
}
}
c := jwtTokenClaims{
Username: user.Username,
Permissions: user.Filters.WebClient,
Signature: user.GetSignature(),
APIKeyID: keyID,
}
resp, err := c.createTokenResponse(tokenAuth, tokenAudienceAPIUser)
if err != nil {
updateLoginMetrics(&user, ipAddr, common.ErrInternalFailure)
return err
}
r.Header.Set("Authorization", fmt.Sprintf("Bearer %v", resp["access_token"]))
dataprovider.UpdateLastLogin(&user)
updateLoginMetrics(&user, ipAddr, nil)
return nil
}
func checkPartialAuth(w http.ResponseWriter, r *http.Request, audience string, tokenAudience []string) error {
if audience == tokenAudienceWebAdmin && util.IsStringInSlice(tokenAudienceWebAdminPartial, tokenAudience) {
http.Redirect(w, r, webAdminTwoFactorPath, http.StatusFound)
return errInvalidToken
}
if audience == tokenAudienceWebClient && util.IsStringInSlice(tokenAudienceWebClientPartial, tokenAudience) {
http.Redirect(w, r, webClientTwoFactorPath, http.StatusFound)
return errInvalidToken
}
return nil
}