TCP client command (#1696)

* add cli commands

* add jwt cache test

* add tcptunnel test

* add stdin/stdout support

* use cryptutil hash function

* doc updates

* fix log timestamp

internal/authclient/authclient_test.go

@@ -0,0 +1,74 @@
+package authclient
+
+import (
+	"context"
+	"net"
+	"net/http"
+	"net/url"
+	"testing"
+	"time"
+
+	"github.com/go-chi/chi"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestAuthClient(t *testing.T) {
+	ctx, clearTimeout := context.WithTimeout(context.Background(), time.Second*30)
+	defer clearTimeout()
+
+	li, err := net.Listen("tcp", "127.0.0.1:0")
+	if !assert.NoError(t, err) {
+		return
+	}
+	defer func() { _ = li.Close() }()
+
+	go func() {
+		h := chi.NewMux()
+		h.Get("/.pomerium/api/v1/login", func(w http.ResponseWriter, r *http.Request) {
+			_, _ = w.Write([]byte(r.FormValue("pomerium_redirect_uri")))
+		})
+		srv := &http.Server{
+			BaseContext: func(li net.Listener) context.Context {
+				return ctx
+			},
+			Handler: h,
+		}
+		_ = srv.Serve(li)
+	}()
+
+	origOpenBrowser := openBrowser
+	defer func() {
+		openBrowser = origOpenBrowser
+	}()
+	openBrowser = func(input string) error {
+		u, err := url.Parse(input)
+		if err != nil {
+			return err
+		}
+		u = u.ResolveReference(&url.URL{
+			RawQuery: url.Values{
+				"pomerium_jwt": {"TEST"},
+			}.Encode(),
+		})
+
+		req, err := http.NewRequestWithContext(ctx, "GET", u.String(), nil)
+		if err != nil {
+			return err
+		}
+
+		res, err := http.DefaultClient.Do(req)
+		if err != nil {
+			return err
+		}
+		_ = res.Body.Close()
+		return nil
+	}
+
+	ac := New()
+	rawJWT, err := ac.GetJWT(ctx, &url.URL{
+		Scheme: "http",
+		Host:   li.Addr().String(),
+	})
+	assert.NoError(t, err)
+	assert.Equal(t, "TEST", rawJWT)
+}