package oauthutil
import (
"context"
"crypto/rand"
"encoding/json"
"fmt"
"html/template"
"log"
"net"
"net/http"
"strings"
"sync"
"time"
"github.com/ncw/rclone/fs"
"github.com/ncw/rclone/fs/config"
"github.com/ncw/rclone/fs/config/configmap"
"github.com/ncw/rclone/fs/fshttp"
"github.com/pkg/errors"
"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 + "/"
// AuthResponse is a template to handle the redirect URL for oauth requests
AuthResponse = `
{{ if .OK }}Success!{{ else }}Failure!{{ end }}
{{ if .OK }}Success!{{ else }}Failure!{{ end }}
{{ if eq .OK false }}
Error: {{ .AuthError.Name }}
{{ if .AuthError.Description }}Description: {{ .AuthError.Description }}
{{ end }}
{{ if .AuthError.Code }}Code: {{ .AuthError.Code }}
{{ end }}
{{ if .AuthError.HelpURL }}Look here for help: {{ .AuthError.HelpURL }}
{{ end }}
{{ else }}
{{ if .Code }}
Please copy this code into rclone:
{{ .Code }}
{{ else }}
All done. Please go back to rclone.
{{ end }}
{{ end }}
`
)
// 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, errors.New("empty token found - please run rclone config again")
}
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 {
err = config.SetValueAndSave(name, config.ConfigToken, tokenString)
if newSection && err != nil {
fs.Debugf(name, "Added new token to config, still needs to be saved")
} else if err != nil {
fs.Errorf(nil, "Failed to save new token in config file: %v", err)
} else {
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
}
// 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()
// 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 {
return nil, err
}
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, 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(client *http.Client) context.Context {
return context.WithValue(context.Background(), 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(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(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(name string, m configmap.Mapper, oauthConfig *oauth2.Config) (*http.Client, *TokenSource, error) {
return NewClientWithBaseClient(name, m, oauthConfig, fshttp.NewClient(fs.Config))
}
// Config does the initial creation of the token
//
// It may run an internal webserver to receive the results
func Config(id, name string, m configmap.Mapper, config *oauth2.Config, opts ...oauth2.AuthCodeOption) error {
return doConfig(id, name, m, nil, config, true, opts)
}
// ConfigNoOffline does the same as Config but does not pass the
// "access_type=offline" parameter.
func ConfigNoOffline(id, name string, m configmap.Mapper, config *oauth2.Config, opts ...oauth2.AuthCodeOption) error {
return doConfig(id, name, m, nil, config, false, opts)
}
// ConfigErrorCheck does the same as Config, but allows the backend to pass a error handling function
// This function gets called with the request made to rclone as a parameter if no code was found
func ConfigErrorCheck(id, name string, m configmap.Mapper, errorHandler func(*http.Request) AuthError, config *oauth2.Config, opts ...oauth2.AuthCodeOption) error {
return doConfig(id, name, m, errorHandler, config, true, opts)
}
func doConfig(id, name string, m configmap.Mapper, errorHandler func(*http.Request) AuthError, oauthConfig *oauth2.Config, offline bool, opts []oauth2.AuthCodeOption) error {
oauthConfig, changed := overrideCredentials(name, m, oauthConfig)
auto, ok := m.Get(config.ConfigAutomatic)
automatic := ok && auto != ""
// See if already have a token
tokenString, ok := m.Get("token")
if ok && tokenString != "" {
fmt.Printf("Already have a token - refresh?\n")
if !config.Confirm() {
return nil
}
}
// Detect whether we should use internal web server
useWebServer := false
switch oauthConfig.RedirectURL {
case RedirectURL, RedirectPublicURL, RedirectLocalhostURL:
if changed {
fmt.Printf("Make sure your Redirect URL is set to %q in your custom config.\n", oauthConfig.RedirectURL)
}
useWebServer = true
if automatic {
break
}
fmt.Printf("Use auto config?\n")
fmt.Printf(" * Say Y if not sure\n")
fmt.Printf(" * Say N if you are working on a remote or headless machine\n")
auto := config.Confirm()
if !auto {
fmt.Printf("For this to work, you will need rclone available on a machine that has a web browser available.\n")
fmt.Printf("Execute the following on your machine:\n")
if changed {
fmt.Printf("\trclone authorize %q %q %q\n", id, oauthConfig.ClientID, oauthConfig.ClientSecret)
} else {
fmt.Printf("\trclone authorize %q\n", id)
}
fmt.Println("Then paste the result below:")
code := ""
for code == "" {
fmt.Printf("result> ")
code = strings.TrimSpace(config.ReadLine())
}
token := &oauth2.Token{}
err := json.Unmarshal([]byte(code), token)
if err != nil {
return err
}
return PutToken(name, m, token, true)
}
case TitleBarRedirectURL:
useWebServer = automatic
if !automatic {
fmt.Printf("Use auto config?\n")
fmt.Printf(" * Say Y if not sure\n")
fmt.Printf(" * Say N if you are working on a remote or headless machine or Y didn't work\n")
useWebServer = config.Confirm()
}
if useWebServer {
// copy the config and set to use the internal webserver
configCopy := *oauthConfig
oauthConfig = &configCopy
oauthConfig.RedirectURL = RedirectURL
}
}
// Make random state
stateBytes := make([]byte, 16)
_, err := rand.Read(stateBytes)
if err != nil {
return err
}
state := fmt.Sprintf("%x", stateBytes)
if offline {
opts = append(opts, oauth2.AccessTypeOffline)
}
authURL := oauthConfig.AuthCodeURL(state, opts...)
// Prepare webserver
server := authServer{
state: state,
bindAddress: bindAddress,
authURL: authURL,
errorHandler: errorHandler,
}
if useWebServer {
server.code = make(chan string, 1)
server.err = make(chan error, 1)
go server.Start()
defer server.Stop()
authURL = "http://" + bindAddress + "/auth"
}
// Generate a URL for the user to visit for authorization.
_ = open.Start(authURL)
fmt.Printf("If your browser doesn't open automatically go to the following link: %s\n", authURL)
fmt.Printf("Log in and authorize rclone for access\n")
var authCode string
if useWebServer {
// Read the code, and exchange it for a token.
fmt.Printf("Waiting for code...\n")
authCode = <-server.code
authError := <-server.err
if authCode != "" {
fmt.Printf("Got code\n")
} else {
if authError != nil {
return authError
}
return errors.New("failed to get code")
}
} else {
// Read the code, and exchange it for a token.
fmt.Printf("Enter verification code> ")
authCode = config.ReadLine()
}
token, err := oauthConfig.Exchange(oauth2.NoContext, authCode)
if err != nil {
return errors.Wrap(err, "failed to get token")
}
// Print code if we do automatic retrieval
if automatic {
result, err := json.Marshal(token)
if err != nil {
return errors.Wrap(err, "failed to marshal token")
}
fmt.Printf("Paste the following into your remote machine --->\n%s\n<---End paste", result)
}
return PutToken(name, m, token, true)
}
// Local web server for collecting auth
type authServer struct {
state string
listener net.Listener
bindAddress string
code chan string
err chan error
authURL string
server *http.Server
errorHandler func(*http.Request) AuthError
}
// AuthError gets returned by the backend's errorHandler function
type AuthError struct {
Name string
Description string
Code string
HelpURL string
}
// AuthResponseData can fill the AuthResponse template
type AuthResponseData struct {
OK bool // Failure or Success?
Code string // code to paste into rclone config
AuthError
}
// startWebServer runs an internal web server to receive config details
func (s *authServer) Start() {
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, "", 404)
return
})
mux.HandleFunc("/auth", func(w http.ResponseWriter, req *http.Request) {
http.Redirect(w, req, s.authURL, http.StatusTemporaryRedirect)
return
})
mux.HandleFunc("/", func(w http.ResponseWriter, req *http.Request) {
w.Header().Set("Content-Type", "text/html")
fs.Debugf(nil, "Received request on auth server")
code := req.FormValue("code")
var err error
var t = template.Must(template.New("authResponse").Parse(AuthResponse))
resp := AuthResponseData{AuthError: AuthError{}}
if code != "" {
state := req.FormValue("state")
if state != s.state {
fs.Debugf(nil, "State did not match: want %q got %q", s.state, state)
resp.OK = false
resp.AuthError = AuthError{
Name: "Auth State doesn't match",
}
} else {
fs.Debugf(nil, "Successfully got code")
resp.OK = true
if s.code == nil {
resp.Code = code
}
}
} else {
fs.Debugf(nil, "No code found on request")
var authError AuthError
if s.errorHandler == nil {
authError = AuthError{
Name: "Auth Error",
Description: "No code found returned by remote server.",
}
} else {
authError = s.errorHandler(req)
}
err = fmt.Errorf("Error: %s\nCode: %s\nDescription: %s\nHelp: %s",
authError.Name, authError.Code, authError.Description, authError.HelpURL)
resp.OK = false
resp.AuthError = authError
w.WriteHeader(500)
}
if err := t.Execute(w, resp); err != nil {
fs.Debugf(nil, "Could not execute template for web response.")
}
if s.code != nil {
s.code <- code
s.err <- err
}
})
var err error
s.listener, err = net.Listen("tcp", s.bindAddress)
if err != nil {
log.Fatalf("Failed to start auth webserver: %v", err)
}
err = s.server.Serve(s.listener)
fs.Debugf(nil, "Closed auth server with error: %v", err)
}