Files
kubelogin/auth/authcode.go
2018-08-30 21:28:17 +09:00

110 lines
2.7 KiB
Go

package auth
import (
"context"
"fmt"
"log"
"net/http"
"time"
"github.com/pkg/browser"
"golang.org/x/oauth2"
)
type authCodeFlow struct {
Config *oauth2.Config
ServerPort int // HTTP server port
SkipOpenBrowser bool // skip opening browser if true
}
func (f *authCodeFlow) getToken(ctx context.Context) (*oauth2.Token, error) {
code, err := f.getAuthCode(ctx)
if err != nil {
return nil, fmt.Errorf("Could not get an auth code: %s", err)
}
token, err := f.Config.Exchange(ctx, code)
if err != nil {
return nil, fmt.Errorf("Could not exchange token: %s", err)
}
return token, nil
}
func (f *authCodeFlow) getAuthCode(ctx context.Context) (string, error) {
state, err := generateState()
if err != nil {
return "", fmt.Errorf("Could not generate state parameter: %s", err)
}
codeCh := make(chan string)
defer close(codeCh)
errCh := make(chan error)
defer close(errCh)
server := http.Server{
Addr: fmt.Sprintf("localhost:%d", f.ServerPort),
Handler: &authCodeHandler{
authCodeURL: f.Config.AuthCodeURL(state),
gotCode: func(code string, gotState string) {
if gotState == state {
codeCh <- code
} else {
errCh <- fmt.Errorf("State does not match, wants %s but %s", state, gotState)
}
},
gotError: func(err error) {
errCh <- err
},
},
}
go func() {
if err := server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
errCh <- err
}
}()
go func() {
log.Printf("Open http://localhost:%d for authorization", f.ServerPort)
if !f.SkipOpenBrowser {
time.Sleep(500 * time.Millisecond)
browser.OpenURL(fmt.Sprintf("http://localhost:%d/", f.ServerPort))
}
}()
select {
case err := <-errCh:
server.Shutdown(ctx)
return "", err
case code := <-codeCh:
server.Shutdown(ctx)
return code, nil
case <-ctx.Done():
server.Shutdown(ctx)
return "", ctx.Err()
}
}
type authCodeHandler struct {
authCodeURL string
gotCode func(code string, state string)
gotError func(err error)
}
func (h *authCodeHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
log.Printf("%s %s", r.Method, r.RequestURI)
m := r.Method
p := r.URL.Path
q := r.URL.Query()
switch {
case m == "GET" && p == "/" && q.Get("error") != "":
h.gotError(fmt.Errorf("OAuth Error: %s %s", q.Get("error"), q.Get("error_description")))
http.Error(w, "OAuth Error", 500)
case m == "GET" && p == "/" && q.Get("code") != "":
h.gotCode(q.Get("code"), q.Get("state"))
w.Header().Add("Content-Type", "text/html")
fmt.Fprintf(w, `<html><body>OK<script>window.close()</script></body></html>`)
case m == "GET" && p == "/":
http.Redirect(w, r, h.authCodeURL, 302)
default:
http.Error(w, "Not Found", 404)
}
}