package oauthutil
import (
"context"
"encoding/json"
"errors"
"fmt"
"html/template"
"net"
"net/http"
"net/url"
"strings"
"sync"
"time"
"github.com/rclone/rclone/fs"
"github.com/rclone/rclone/fs/config"
"github.com/rclone/rclone/fs/config/configmap"
"github.com/rclone/rclone/fs/fserrors"
"github.com/rclone/rclone/fs/fshttp"
"github.com/rclone/rclone/lib/random"
"github.com/skratchdot/open-golang/open"
"golang.org/x/oauth2"
)
const (
// TitleBarRedirectURL is the OAuth2 redirect URL to use when the authorization
// code should be returned in the title bar of the browser, with the page text
// prompting the user to copy the code and paste it in the application.
TitleBarRedirectURL = "urn:ietf:wg:oauth:2.0:oob"
// bindPort is the port that we bind the local webserver to
bindPort = "53682"
// bindAddress is binding for local webserver when active
bindAddress = "127.0.0.1:" + bindPort
// RedirectURL is redirect to local webserver when active
RedirectURL = "http://" + bindAddress + "/"
// RedirectPublicURL is redirect to local webserver when active with public name
RedirectPublicURL = "http://localhost.rclone.org:" + bindPort + "/"
// RedirectLocalhostURL is redirect to local webserver when active with localhost
RedirectLocalhostURL = "http://localhost:" + bindPort + "/"
// RedirectPublicSecureURL is a public https URL which
// redirects to the local webserver
RedirectPublicSecureURL = "https://oauth.rclone.org/"
// AuthResponseTemplate is a template to handle the redirect URL for oauth requests
AuthResponseTemplate = `
{{ if .OK }}Success!{{ else }}Failure!{{ end }}
{{ if .OK }}Success!{{ else }}Failure!{{ end }}
{{ if eq .OK false }}
Error: {{ .Name }}
{{ if .Description }}Description: {{ .Description }}
{{ end }}
{{ if .Code }}Code: {{ .Code }}
{{ end }}
{{ if .HelpURL }}Look here for help: {{ .HelpURL }}
{{ end }}
{{ else }}
All done. Please go back to rclone.
{{ end }}
`
)
// SharedOptions are shared between backends the utilize an OAuth flow
var SharedOptions = []fs.Option{{
Name: config.ConfigClientID,
Help: "OAuth Client Id.\n\nLeave blank normally.",
}, {
Name: config.ConfigClientSecret,
Help: "OAuth Client Secret.\n\nLeave blank normally.",
}, {
Name: config.ConfigToken,
Help: "OAuth Access Token as a JSON blob.",
Advanced: true,
}, {
Name: config.ConfigAuthURL,
Help: "Auth server URL.\n\nLeave blank to use the provider defaults.",
Advanced: true,
}, {
Name: config.ConfigTokenURL,
Help: "Token server url.\n\nLeave blank to use the provider defaults.",
Advanced: true,
}}
// oldToken contains an end-user's tokens.
// This is the data you must store to persist authentication.
//
// From the original code.google.com/p/goauth2/oauth package - used
// for backwards compatibility in the rclone config file
type oldToken struct {
AccessToken string
RefreshToken string
Expiry time.Time
}
// GetToken returns the token saved in the config file under
// section name.
func GetToken(name string, m configmap.Mapper) (*oauth2.Token, error) {
tokenString, ok := m.Get(config.ConfigToken)
if !ok || tokenString == "" {
return nil, fmt.Errorf("empty token found - please run \"rclone config reconnect %s:\"", name)
}
token := new(oauth2.Token)
err := json.Unmarshal([]byte(tokenString), token)
if err != nil {
return nil, err
}
// if has data then return it
if token.AccessToken != "" {
return token, nil
}
// otherwise try parsing as oldToken
oldtoken := new(oldToken)
err = json.Unmarshal([]byte(tokenString), oldtoken)
if err != nil {
return nil, err
}
// Fill in result into new token
token.AccessToken = oldtoken.AccessToken
token.RefreshToken = oldtoken.RefreshToken
token.Expiry = oldtoken.Expiry
// Save new format in config file
err = PutToken(name, m, token, false)
if err != nil {
return nil, err
}
return token, nil
}
// PutToken stores the token in the config file
//
// This saves the config file if it changes
func PutToken(name string, m configmap.Mapper, token *oauth2.Token, newSection bool) error {
tokenBytes, err := json.Marshal(token)
if err != nil {
return err
}
tokenString := string(tokenBytes)
old, ok := m.Get(config.ConfigToken)
if !ok || tokenString != old {
m.Set(config.ConfigToken, tokenString)
fs.Debugf(name, "Saved new token in config file")
}
return nil
}
// TokenSource stores updated tokens in the config file
type TokenSource struct {
mu sync.Mutex
name string
m configmap.Mapper
tokenSource oauth2.TokenSource
token *oauth2.Token
config *oauth2.Config
ctx context.Context
expiryTimer *time.Timer // signals whenever the token expires
}
// If token has expired then first try re-reading it (and its refresh token)
// from the config file in case a concurrently running rclone has updated them
// already.
// Returns whether either of the two tokens has been reread.
func (ts *TokenSource) reReadToken() (changed bool) {
tokenString, found := ts.m.Get(config.ConfigToken)
if !found || tokenString == "" {
fs.Debugf(ts.name, "Failed to read token out of config file")
return false
}
newToken := new(oauth2.Token)
err := json.Unmarshal([]byte(tokenString), newToken)
if err != nil {
fs.Debugf(ts.name, "Failed to parse token out of config file: %v", err)
return false
}
if !newToken.Valid() {
fs.Debugf(ts.name, "Loaded invalid token from config file - ignoring")
} else {
fs.Debugf(ts.name, "Loaded fresh token from config file")
changed = true
}
if newToken.RefreshToken != "" && newToken.RefreshToken != ts.token.RefreshToken {
fs.Debugf(ts.name, "Loaded new refresh token from config file")
changed = true
}
if changed {
ts.token = newToken
ts.tokenSource = nil // invalidate since we changed the token
}
return changed
}
// Token returns a token or an error.
// Token must be safe for concurrent use by multiple goroutines.
// The returned Token must not be modified.
//
// This saves the token in the config file if it has changed
func (ts *TokenSource) Token() (*oauth2.Token, error) {
ts.mu.Lock()
defer ts.mu.Unlock()
var (
token *oauth2.Token
err error
changed = false
)
const maxTries = 5
// Try getting the token a few times
for i := 1; i <= maxTries; i++ {
// Try reading the token from the config file in case it has
// been updated by a concurrent rclone process
if !ts.token.Valid() {
if ts.reReadToken() {
changed = true
} else if ts.token.RefreshToken == "" {
return nil, fserrors.FatalError(
fmt.Errorf("token expired and there's no refresh token - manually refresh with \"rclone config reconnect %s:\"", ts.name),
)
}
}
// Make a new token source if required
if ts.tokenSource == nil {
ts.tokenSource = ts.config.TokenSource(ts.ctx, ts.token)
}
token, err = ts.tokenSource.Token()
if err == nil {
break
}
fs.Debugf(ts.name, "Token refresh failed try %d/%d: %v", i, maxTries, err)
time.Sleep(1 * time.Second)
}
if err != nil {
return nil, fmt.Errorf("couldn't fetch token - maybe it has expired? - refresh with \"rclone config reconnect %s:\": %w", ts.name, err)
}
changed = changed || (*token != *ts.token)
ts.token = token
if changed {
// Bump on the expiry timer if it is set
if ts.expiryTimer != nil {
ts.expiryTimer.Reset(ts.timeToExpiry())
}
err = PutToken(ts.name, ts.m, token, false)
if err != nil {
return nil, fmt.Errorf("couldn't store token: %w", err)
}
}
return token, nil
}
// Invalidate invalidates the token
func (ts *TokenSource) Invalidate() {
ts.mu.Lock()
ts.token.AccessToken = ""
ts.mu.Unlock()
}
// timeToExpiry returns how long until the token expires
//
// Call with the lock held
func (ts *TokenSource) timeToExpiry() time.Duration {
t := ts.token
if t == nil {
return 0
}
if t.Expiry.IsZero() {
return 3e9 * time.Second // ~95 years
}
return t.Expiry.Sub(time.Now())
}
// OnExpiry returns a channel which has the time written to it when
// the token expires. Note that there is only one channel so if
// attaching multiple go routines it will only signal to one of them.
func (ts *TokenSource) OnExpiry() <-chan time.Time {
ts.mu.Lock()
defer ts.mu.Unlock()
if ts.expiryTimer == nil {
ts.expiryTimer = time.NewTimer(ts.timeToExpiry())
}
return ts.expiryTimer.C
}
// Check interface satisfied
var _ oauth2.TokenSource = (*TokenSource)(nil)
// Context returns a context with our HTTP Client baked in for oauth2
func Context(ctx context.Context, client *http.Client) context.Context {
return context.WithValue(ctx, oauth2.HTTPClient, client)
}
// overrideCredentials sets the ClientID and ClientSecret from the
// config file if they are not blank.
// If any value is overridden, true is returned.
// the origConfig is copied
func overrideCredentials(name string, m configmap.Mapper, origConfig *oauth2.Config) (newConfig *oauth2.Config, changed bool) {
newConfig = new(oauth2.Config)
*newConfig = *origConfig
changed = false
ClientID, ok := m.Get(config.ConfigClientID)
if ok && ClientID != "" {
newConfig.ClientID = ClientID
changed = true
}
ClientSecret, ok := m.Get(config.ConfigClientSecret)
if ok && ClientSecret != "" {
newConfig.ClientSecret = ClientSecret
changed = true
}
AuthURL, ok := m.Get(config.ConfigAuthURL)
if ok && AuthURL != "" {
newConfig.Endpoint.AuthURL = AuthURL
changed = true
}
TokenURL, ok := m.Get(config.ConfigTokenURL)
if ok && TokenURL != "" {
newConfig.Endpoint.TokenURL = TokenURL
changed = true
}
return newConfig, changed
}
// NewClientWithBaseClient gets a token from the config file and
// configures a Client with it. It returns the client and a
// TokenSource which Invalidate may need to be called on. It uses the
// httpClient passed in as the base client.
func NewClientWithBaseClient(ctx context.Context, name string, m configmap.Mapper, config *oauth2.Config, baseClient *http.Client) (*http.Client, *TokenSource, error) {
config, _ = overrideCredentials(name, m, config)
token, err := GetToken(name, m)
if err != nil {
return nil, nil, err
}
// Set our own http client in the context
ctx = Context(ctx, baseClient)
// Wrap the TokenSource in our TokenSource which saves changed
// tokens in the config file
ts := &TokenSource{
name: name,
m: m,
token: token,
config: config,
ctx: ctx,
}
return oauth2.NewClient(ctx, ts), ts, nil
}
// NewClient gets a token from the config file and configures a Client
// with it. It returns the client and a TokenSource which Invalidate may need to be called on
func NewClient(ctx context.Context, name string, m configmap.Mapper, oauthConfig *oauth2.Config) (*http.Client, *TokenSource, error) {
return NewClientWithBaseClient(ctx, name, m, oauthConfig, fshttp.NewClient(ctx))
}
// AuthResult is returned from the web server after authorization
// success or failure
type AuthResult struct {
OK bool // Failure or Success?
Name string
Description string
Code string
HelpURL string
Form url.Values // the complete contents of the form
Err error // any underlying error to report
}
// Error satisfies the error interface so AuthResult can be used as an error
func (ar *AuthResult) Error() string {
status := "Error"
if ar.OK {
status = "OK"
}
return fmt.Sprintf("%s: %s\nCode: %q\nDescription: %s\nHelp: %s",
status, ar.Name, ar.Code, ar.Description, ar.HelpURL)
}
// CheckAuthFn is called when a good Auth has been received
type CheckAuthFn func(*oauth2.Config, *AuthResult) error
// Options for the oauth config
type Options struct {
OAuth2Config *oauth2.Config // Basic config for oauth2
NoOffline bool // If set then "access_type=offline" parameter is not passed
CheckAuth CheckAuthFn // When the AuthResult is known the checkAuth function is called if set
OAuth2Opts []oauth2.AuthCodeOption // extra oauth2 options
StateBlankOK bool // If set, state returned as "" is deemed to be OK
}
// ConfigOut returns a config item suitable for the backend config
//
// state is the place to return the config to
// oAuth is the config to run the oauth with
func ConfigOut(state string, oAuth *Options) (*fs.ConfigOut, error) {
return &fs.ConfigOut{
State: state,
OAuth: oAuth,
}, nil
}
// ConfigOAuth does the oauth config specified in the config block
//
// This is called with a state which has pushed on it
//
// state prefixed with "*oauth"
// state for oauth to return to
// state that returned the OAuth when we wish to recall it
// value that returned the OAuth
func ConfigOAuth(ctx context.Context, name string, m configmap.Mapper, ri *fs.RegInfo, in fs.ConfigIn) (*fs.ConfigOut, error) {
stateParams, state := fs.StatePop(in.State)
// Make the next state
newState := func(state string) string {
return fs.StatePush(stateParams, state)
}
// Recall the Oauth state again by calling the Config with the same input again
getOAuth := func() (opt *Options, err error) {
tmpState, _ := fs.StatePop(stateParams)
tmpState, State := fs.StatePop(tmpState)
_, Result := fs.StatePop(tmpState)
out, err := ri.Config(ctx, name, m, fs.ConfigIn{State: State, Result: Result})
if err != nil {
return nil, err
}
if out.OAuth == nil {
return nil, errors.New("failed to recall OAuth state")
}
opt, ok := out.OAuth.(*Options)
if !ok {
return nil, fmt.Errorf("internal error: oauth failed: wrong type in config: %T", out.OAuth)
}
if opt.OAuth2Config == nil {
return nil, errors.New("internal error: oauth failed: OAuth2Config not set")
}
return opt, nil
}
switch state {
case "*oauth":
// See if already have a token
tokenString, ok := m.Get("token")
if ok && tokenString != "" {
return fs.ConfigConfirm(newState("*oauth-confirm"), true, "config_refresh_token", "Already have a token - refresh?")
}
return fs.ConfigGoto(newState("*oauth-confirm"))
case "*oauth-confirm":
if in.Result == "false" {
return fs.ConfigGoto(newState("*oauth-done"))
}
return fs.ConfigConfirm(newState("*oauth-islocal"), true, "config_is_local", "Use auto config?\n * Say Y if not sure\n * Say N if you are working on a remote or headless machine\n")
case "*oauth-islocal":
if in.Result == "true" {
return fs.ConfigGoto(newState("*oauth-do"))
}
return fs.ConfigGoto(newState("*oauth-remote"))
case "*oauth-remote":
opt, err := getOAuth()
if err != nil {
return nil, err
}
if noWebserverNeeded(opt.OAuth2Config) {
authURL, _, err := getAuthURL(name, m, opt.OAuth2Config, opt)
if err != nil {
return nil, err
}
return fs.ConfigInput(newState("*oauth-do"), "config_verification_code", fmt.Sprintf("Verification code\n\nGo to this URL, authenticate then paste the code here.\n\n%s\n", authURL))
}
var out strings.Builder
fmt.Fprintf(&out, `For this to work, you will need rclone available on a machine that has
a web browser available.
For more help and alternate methods see: https://rclone.org/remote_setup/
Execute the following on the machine with the web browser (same rclone
version recommended):
`)
// Find the overridden options
inM := ri.Options.NonDefault(m)
delete(inM, fs.ConfigToken) // delete token as we are refreshing it
for k, v := range inM {
fs.Debugf(nil, "sending %s = %q", k, v)
}
// Encode them into a string
mCopyString, err := inM.Encode()
if err != nil {
return nil, fmt.Errorf("oauthutil authorize encode: %w", err)
}
// Write what the user has to do
if len(mCopyString) > 0 {
fmt.Fprintf(&out, "\trclone authorize %q %q\n", ri.Name, mCopyString)
} else {
fmt.Fprintf(&out, "\trclone authorize %q\n", ri.Name)
}
fmt.Fprintln(&out, "\nThen paste the result.")
return fs.ConfigInput(newState("*oauth-authorize"), "config_token", out.String())
case "*oauth-authorize":
// Read the updates to the config
outM := configmap.Simple{}
token := oauth2.Token{}
code := in.Result
newFormat := true
err := outM.Decode(code)
if err != nil {
newFormat = false
err = json.Unmarshal([]byte(code), &token)
}
if err != nil {
return fs.ConfigError(newState("*oauth-authorize"), fmt.Sprintf("Couldn't decode response - try again (make sure you are using a matching version of rclone on both sides: %v\n", err))
}
// Save the config updates
if newFormat {
for k, v := range outM {
m.Set(k, v)
fs.Debugf(nil, "received %s = %q", k, v)
}
} else {
m.Set(fs.ConfigToken, code)
}
return fs.ConfigGoto(newState("*oauth-done"))
case "*oauth-do":
code := in.Result
opt, err := getOAuth()
if err != nil {
return nil, err
}
oauthConfig, changed := overrideCredentials(name, m, opt.OAuth2Config)
if changed {
fs.Logf(nil, "Make sure your Redirect URL is set to %q in your custom config.\n", oauthConfig.RedirectURL)
}
if code == "" {
oauthConfig = fixRedirect(oauthConfig)
code, err = configSetup(ctx, ri.Name, name, m, oauthConfig, opt)
if err != nil {
return nil, fmt.Errorf("config failed to refresh token: %w", err)
}
}
err = configExchange(ctx, name, m, oauthConfig, code)
if err != nil {
return nil, err
}
return fs.ConfigGoto(newState("*oauth-done"))
case "*oauth-done":
// Return to the state indicated in the State stack
_, returnState := fs.StatePop(stateParams)
return fs.ConfigGoto(returnState)
}
return nil, fmt.Errorf("unknown internal oauth state %q", state)
}
func init() {
// Set the function to avoid circular import
fs.ConfigOAuth = ConfigOAuth
}
// Return true if can run without a webserver and just entering a code
func noWebserverNeeded(oauthConfig *oauth2.Config) bool {
return oauthConfig.RedirectURL == TitleBarRedirectURL
}
// get the URL we need to send the user to
func getAuthURL(name string, m configmap.Mapper, oauthConfig *oauth2.Config, opt *Options) (authURL string, state string, err error) {
oauthConfig, _ = overrideCredentials(name, m, oauthConfig)
// Make random state
state, err = random.Password(128)
if err != nil {
return "", "", err
}
// Generate oauth URL
opts := opt.OAuth2Opts
if !opt.NoOffline {
opts = append(opts, oauth2.AccessTypeOffline)
}
authURL = oauthConfig.AuthCodeURL(state, opts...)
return authURL, state, nil
}
// If TitleBarRedirect is set but we are doing a real oauth, then
// override our redirect URL
func fixRedirect(oauthConfig *oauth2.Config) *oauth2.Config {
switch oauthConfig.RedirectURL {
case TitleBarRedirectURL:
// copy the config and set to use the internal webserver
configCopy := *oauthConfig
oauthConfig = &configCopy
oauthConfig.RedirectURL = RedirectURL
}
return oauthConfig
}
// configSetup does the initial creation of the token
//
// If opt is nil it will use the default Options
//
// It will run an internal webserver to receive the results
func configSetup(ctx context.Context, id, name string, m configmap.Mapper, oauthConfig *oauth2.Config, opt *Options) (string, error) {
if opt == nil {
opt = &Options{}
}
authorizeNoAutoBrowserValue, ok := m.Get(config.ConfigAuthNoBrowser)
authorizeNoAutoBrowser := ok && authorizeNoAutoBrowserValue != ""
authURL, state, err := getAuthURL(name, m, oauthConfig, opt)
if err != nil {
return "", err
}
// Prepare webserver
server := newAuthServer(opt, bindAddress, state, authURL)
err = server.Init()
if err != nil {
return "", fmt.Errorf("failed to start auth webserver: %w", err)
}
go server.Serve()
defer server.Stop()
authURL = "http://" + bindAddress + "/auth?state=" + state
if !authorizeNoAutoBrowser {
// Open the URL for the user to visit
_ = open.Start(authURL)
fs.Logf(nil, "If your browser doesn't open automatically go to the following link: %s\n", authURL)
} else {
fs.Logf(nil, "Please go to the following link: %s\n", authURL)
}
fs.Logf(nil, "Log in and authorize rclone for access\n")
// Read the code via the webserver
fs.Logf(nil, "Waiting for code...\n")
auth := <-server.result
if !auth.OK || auth.Code == "" {
return "", auth
}
fs.Logf(nil, "Got code\n")
if opt.CheckAuth != nil {
err = opt.CheckAuth(oauthConfig, auth)
if err != nil {
return "", err
}
}
return auth.Code, nil
}
// Exchange the code for a token
func configExchange(ctx context.Context, name string, m configmap.Mapper, oauthConfig *oauth2.Config, code string) error {
ctx = Context(ctx, fshttp.NewClient(ctx))
token, err := oauthConfig.Exchange(ctx, code)
if err != nil {
return fmt.Errorf("failed to get token: %w", err)
}
return PutToken(name, m, token, true)
}
// Local web server for collecting auth
type authServer struct {
opt *Options
state string
listener net.Listener
bindAddress string
authURL string
server *http.Server
result chan *AuthResult
}
// newAuthServer makes the webserver for collecting auth
func newAuthServer(opt *Options, bindAddress, state, authURL string) *authServer {
return &authServer{
opt: opt,
state: state,
bindAddress: bindAddress,
authURL: authURL, // http://host/auth redirects to here
result: make(chan *AuthResult, 1),
}
}
// Receive the auth request
func (s *authServer) handleAuth(w http.ResponseWriter, req *http.Request) {
fs.Debugf(nil, "Received %s request on auth server to %q", req.Method, req.URL.Path)
// Reply with the response to the user and to the channel
reply := func(status int, res *AuthResult) {
w.WriteHeader(status)
w.Header().Set("Content-Type", "text/html")
var t = template.Must(template.New("authResponse").Parse(AuthResponseTemplate))
if err := t.Execute(w, res); err != nil {
fs.Debugf(nil, "Could not execute template for web response.")
}
s.result <- res
}
// Parse the form parameters and save them
err := req.ParseForm()
if err != nil {
reply(http.StatusBadRequest, &AuthResult{
Name: "Parse form error",
Description: err.Error(),
})
return
}
// get code, error if empty
code := req.Form.Get("code")
if code == "" {
reply(http.StatusBadRequest, &AuthResult{
Name: "Auth Error",
Description: "No code returned by remote server",
})
return
}
// check state
state := req.Form.Get("state")
if state != s.state && !(state == "" && s.opt.StateBlankOK) {
reply(http.StatusBadRequest, &AuthResult{
Name: "Auth state doesn't match",
Description: fmt.Sprintf("Expecting %q got %q", s.state, state),
})
return
}
// code OK
reply(http.StatusOK, &AuthResult{
OK: true,
Code: code,
Form: req.Form,
})
}
// Init gets the internal web server ready to receive config details
func (s *authServer) Init() error {
fs.Debugf(nil, "Starting auth server on %s", s.bindAddress)
mux := http.NewServeMux()
s.server = &http.Server{
Addr: s.bindAddress,
Handler: mux,
}
s.server.SetKeepAlivesEnabled(false)
mux.HandleFunc("/favicon.ico", func(w http.ResponseWriter, req *http.Request) {
http.Error(w, "", http.StatusNotFound)
return
})
mux.HandleFunc("/auth", func(w http.ResponseWriter, req *http.Request) {
state := req.FormValue("state")
if state != s.state {
fs.Debugf(nil, "State did not match: want %q got %q", s.state, state)
http.Error(w, "State did not match - please try again", http.StatusForbidden)
return
}
fs.Debugf(nil, "Redirecting browser to: %s", s.authURL)
http.Redirect(w, req, s.authURL, http.StatusTemporaryRedirect)
return
})
mux.HandleFunc("/", s.handleAuth)
var err error
s.listener, err = net.Listen("tcp", s.bindAddress)
if err != nil {
return err
}
return nil
}
// Serve the auth server, doesn't return
func (s *authServer) Serve() {
err := s.server.Serve(s.listener)
fs.Debugf(nil, "Closed auth server with error: %v", err)
}
// Stop the auth server by closing its socket
func (s *authServer) Stop() {
fs.Debugf(nil, "Closing auth server")
close(s.result)
_ = s.listener.Close()
// close the server
_ = s.server.Close()
}