Move binaries into cmd/ directory

1 files changed, 246 insertions, 0 deletions

diff --git a/cmd/cashierd/main.go b/cmd/cashierd/main.go
new file mode 100644
index 0000000..bc460da
--- /dev/null
+++ b/cmd/cashierd/main.go
@@ -0,0 +1,246 @@
+package main
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"flag"
+	"fmt"
+	"html/template"
+	"io"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"os"
+	"strings"
+	"time"
+
+	"golang.org/x/oauth2"
+
+	"github.com/gorilla/mux"
+	"github.com/gorilla/sessions"
+	"github.com/nsheridan/cashier/lib"
+	"github.com/nsheridan/cashier/server/auth"
+	"github.com/nsheridan/cashier/server/auth/github"
+	"github.com/nsheridan/cashier/server/auth/google"
+	"github.com/nsheridan/cashier/server/config"
+	"github.com/nsheridan/cashier/server/signer"
+)
+
+var (
+	cfg = flag.String("config_file", "config.json", "Path to configuration file.")
+)
+
+// appContext contains local context - cookiestore, authprovider, authsession, templates etc.
+type appContext struct {
+	cookiestore  *sessions.CookieStore
+	authprovider auth.Provider
+	authsession  *auth.Session
+	views        *template.Template
+	sshKeySigner *signer.KeySigner
+}
+
+// getAuthCookie retrieves a cookie from the request and validates it.
+func (a *appContext) getAuthCookie(r *http.Request) *oauth2.Token {
+	session, _ := a.cookiestore.Get(r, "tok")
+	t, ok := session.Values["token"]
+	if !ok {
+		return nil
+	}
+	var tok oauth2.Token
+	if err := json.Unmarshal(t.([]byte), &tok); err != nil {
+		return nil
+	}
+	if !tok.Valid() {
+		return nil
+	}
+	return &tok
+}
+
+// setAuthCookie marshals the auth token and stores it as a cookie.
+func (a *appContext) setAuthCookie(w http.ResponseWriter, r *http.Request, t *oauth2.Token) {
+	session, _ := a.cookiestore.Get(r, "tok")
+	val, _ := json.Marshal(t)
+	session.Values["token"] = val
+	session.Save(r, w)
+}
+
+// parseKey retrieves and unmarshals the signing request.
+func parseKey(r *http.Request) (*lib.SignRequest, error) {
+	var s lib.SignRequest
+	body, err := ioutil.ReadAll(r.Body)
+	if err != nil {
+		return nil, err
+	}
+	if err := json.Unmarshal(body, &s); err != nil {
+		return nil, err
+	}
+	return &s, nil
+}
+
+// signHandler handles the "/sign" path.
+// It unmarshals the client token to an oauth token, validates it and signs the provided public ssh key.
+func signHandler(a *appContext, w http.ResponseWriter, r *http.Request) (int, error) {
+	var t string
+	if ah := r.Header.Get("Authorization"); ah != "" {
+		if len(ah) > 6 && strings.ToUpper(ah[0:7]) == "BEARER " {
+			t = ah[7:]
+		}
+	}
+	if t == "" {
+		return http.StatusUnauthorized, errors.New(http.StatusText(http.StatusUnauthorized))
+	}
+	token := &oauth2.Token{
+		AccessToken: t,
+	}
+	ok := a.authprovider.Valid(token)
+	if !ok {
+		return http.StatusUnauthorized, errors.New(http.StatusText(http.StatusUnauthorized))
+	}
+
+	// Sign the pubkey and issue the cert.
+	req, err := parseKey(r)
+	req.Principal = a.authprovider.Username(token)
+	a.authprovider.Revoke(token) // We don't need this anymore.
+	if err != nil {
+		return http.StatusInternalServerError, err
+	}
+	signed, err := a.sshKeySigner.SignUserKey(req)
+	if err != nil {
+		return http.StatusInternalServerError, err
+	}
+	json.NewEncoder(w).Encode(&lib.SignResponse{
+		Status:   "ok",
+		Response: signed,
+	})
+	return http.StatusOK, nil
+}
+
+// loginHandler starts the authentication process with the provider.
+func loginHandler(a *appContext, w http.ResponseWriter, r *http.Request) (int, error) {
+	a.authsession = a.authprovider.StartSession(newState())
+	http.Redirect(w, r, a.authsession.AuthURL, http.StatusFound)
+	return http.StatusFound, nil
+}
+
+// callbackHandler handles retrieving the access token from the auth provider and saves it for later use.
+func callbackHandler(a *appContext, w http.ResponseWriter, r *http.Request) (int, error) {
+	if r.FormValue("state") != a.authsession.State {
+		return http.StatusUnauthorized, errors.New(http.StatusText(http.StatusUnauthorized))
+	}
+	code := r.FormValue("code")
+	if err := a.authsession.Authorize(a.authprovider, code); err != nil {
+		return http.StatusInternalServerError, err
+	}
+	// Github tokens don't have an expiry. Set one so that the session expires
+	// after a period.
+	if a.authsession.Token.Expiry.Unix() <= 0 {
+		a.authsession.Token.Expiry = time.Now().Add(1 * time.Hour)
+	}
+	a.setAuthCookie(w, r, a.authsession.Token)
+	http.Redirect(w, r, "/", http.StatusFound)
+	return http.StatusFound, nil
+}
+
+// rootHandler starts the auth process. If the client is authenticated it renders the token to the user.
+func rootHandler(a *appContext, w http.ResponseWriter, r *http.Request) (int, error) {
+	tok := a.getAuthCookie(r)
+	if !tok.Valid() || !a.authprovider.Valid(tok) {
+		http.Redirect(w, r, "/auth/login", http.StatusSeeOther)
+		return http.StatusSeeOther, nil
+	}
+	page := struct {
+		Token string
+	}{tok.AccessToken}
+	a.views.ExecuteTemplate(w, "token.html", page)
+	return http.StatusOK, nil
+}
+
+// appHandler is a handler which uses appContext to manage state.
+type appHandler struct {
+	*appContext
+	h func(*appContext, http.ResponseWriter, *http.Request) (int, error)
+}
+
+// ServeHTTP handles the request and writes responses.
+func (ah appHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	status, err := ah.h(ah.appContext, w, r)
+	if err != nil {
+		log.Printf("HTTP %d: %q", status, err)
+		switch status {
+		case http.StatusNotFound:
+			http.NotFound(w, r)
+		case http.StatusInternalServerError:
+			http.Error(w, http.StatusText(status), status)
+		default:
+			http.Error(w, http.StatusText(status), status)
+		}
+	}
+}
+
+// newState generates a state identifier for the oauth process.
+func newState() string {
+	k := make([]byte, 32)
+	if _, err := io.ReadFull(rand.Reader, k); err != nil {
+		return "unexpectedstring"
+	}
+	return hex.EncodeToString(k)
+}
+
+func readConfig(filename string) (*config.Config, error) {
+	f, err := os.Open(filename)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+	return config.ReadConfig(f)
+}
+
+func main() {
+	flag.Parse()
+	config, err := readConfig(*cfg)
+	if err != nil {
+		log.Fatal(err)
+	}
+	signer, err := signer.New(config.SSH)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	var authprovider auth.Provider
+	switch config.Auth.Provider {
+	case "google":
+		authprovider = google.New(&config.Auth)
+	case "github":
+		authprovider = github.New(&config.Auth)
+	default:
+		log.Fatalln("Unknown provider %s", config.Auth.Provider)
+	}
+
+	ctx := &appContext{
+		cookiestore:  sessions.NewCookieStore([]byte(config.Server.CookieSecret)),
+		authprovider: authprovider,
+		views:        template.Must(template.ParseGlob("templates/*")),
+		sshKeySigner: signer,
+	}
+	ctx.cookiestore.Options = &sessions.Options{
+		MaxAge:   900,
+		Path:     "/",
+		Secure:   config.Server.UseTLS,
+		HttpOnly: true,
+	}
+
+	m := mux.NewRouter()
+	m.Handle("/", appHandler{ctx, rootHandler})
+	m.Handle("/auth/login", appHandler{ctx, loginHandler})
+	m.Handle("/auth/callback", appHandler{ctx, callbackHandler})
+	m.Handle("/sign", appHandler{ctx, signHandler})
+
+	fmt.Println("Starting server...")
+	l := fmt.Sprintf(":%d", config.Server.Port)
+	if config.Server.UseTLS {
+		log.Fatal(http.ListenAndServeTLS(l, config.Server.TLSCert, config.Server.TLSKey, m))
+	}
+	log.Fatal(http.ListenAndServe(l, m))
+}