feat(cli): added implementation for codeflow with a cli (#26)

pkg/cli/cli.go

@@ -0,0 +1,107 @@
+package cli
+
+import (
+	"context"
+	"fmt"
+	"github.com/caos/oidc/pkg/oidc"
+	"github.com/caos/oidc/pkg/rp"
+	"github.com/caos/oidc/pkg/utils"
+	"github.com/google/uuid"
+	"github.com/sirupsen/logrus"
+	"log"
+	"net/http"
+	"strings"
+	"time"
+)
+
+func CodeFlow(rpc *rp.Config, key []byte, callbackPath string, port string) *oidc.Tokens {
+	cookieHandler := utils.NewCookieHandler(key, key, utils.WithUnsecure())
+	provider, err := rp.NewDefaultRP(rpc, rp.WithCookieHandler(cookieHandler)) //rp.WithPKCE(cookieHandler)) //,
+	if err != nil {
+		logrus.Fatalf("error creating provider %s", err.Error())
+	}
+
+	return codeFlow(provider, callbackPath, port)
+}
+
+func CodeFlowForClient(rpc *rp.Config, key []byte, callbackPath string, port string) *http.Client {
+	cookieHandler := utils.NewCookieHandler(key, key, utils.WithUnsecure())
+	provider, err := rp.NewDefaultRP(rpc, rp.WithCookieHandler(cookieHandler)) //rp.WithPKCE(cookieHandler)) //,
+	if err != nil {
+		logrus.Fatalf("error creating provider %s", err.Error())
+	}
+	token := codeFlow(provider, callbackPath, port)
+
+	return provider.Client(context.Background(), token.Token)
+}
+
+func codeFlow(provider rp.DelegationTokenExchangeRP, callbackPath string, port string) *oidc.Tokens {
+	loginPath := "/login"
+	portStr := port
+	if !strings.HasPrefix(port, ":") {
+		portStr = strings.Join([]string{":", portStr}, "")
+	}
+
+	getToken, setToken := getAndSetTokens()
+
+	state := uuid.New().String()
+	http.Handle(loginPath, provider.AuthURLHandler(state))
+
+	marshal := func(w http.ResponseWriter, r *http.Request, tokens *oidc.Tokens, state string) {
+		setToken(w, tokens)
+	}
+	http.Handle(callbackPath, provider.CodeExchangeHandler(marshal))
+
+	// start  http-server
+	stopHttpServer := startHttpServer(portStr)
+
+	// open browser in different window
+	utils.OpenBrowser(strings.Join([]string{"http://localhost", portStr, loginPath}, ""))
+
+	// wait until user is logged into browser
+	ret := getToken()
+
+	// stop http-server as no callback is needed anymore
+	stopHttpServer()
+
+	// return tokens
+	return ret
+}
+
+func startHttpServer(port string) func() {
+	srv := &http.Server{Addr: port}
+	go func() {
+
+		// always returns error. ErrServerClosed on graceful close
+		if err := srv.ListenAndServe(); err != http.ErrServerClosed {
+			// unexpected error. port in use?
+			log.Fatalf("ListenAndServe(): %v", err)
+		}
+	}()
+
+	return func() {
+		ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+		defer cancel()
+
+		if err := srv.Shutdown(ctx); err != nil {
+			log.Fatalf("Shutdown(): %v", err)
+		}
+	}
+}
+
+func getAndSetTokens() (func() *oidc.Tokens, func(w http.ResponseWriter, tokens *oidc.Tokens)) {
+	marshalChan := make(chan *oidc.Tokens)
+
+	getToken := func() *oidc.Tokens {
+		return <-marshalChan
+	}
+	setToken := func(w http.ResponseWriter, tokens *oidc.Tokens) {
+		marshalChan <- tokens
+
+		msg := "<p><strong>Success!</strong></p>"
+		msg = msg + "<p>You are authenticated and can now return to the CLI.</p>"
+		fmt.Fprintf(w, msg)
+	}
+
+	return getToken, setToken
+}