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Diffstat (limited to 'server/web.go')
-rw-r--r--server/web.go313
1 files changed, 313 insertions, 0 deletions
diff --git a/server/web.go b/server/web.go
new file mode 100644
index 0000000..65eca49
--- /dev/null
+++ b/server/web.go
@@ -0,0 +1,313 @@
+package server
+
+import (
+ "crypto/rand"
+ "encoding/hex"
+ "encoding/json"
+ "html/template"
+ "io"
+ "log"
+ "net"
+ "net/http"
+ "os"
+ "strconv"
+ "strings"
+
+ "github.com/pkg/errors"
+ "github.com/prometheus/client_golang/prometheus/promhttp"
+
+ "golang.org/x/oauth2"
+
+ "github.com/gorilla/csrf"
+ "github.com/gorilla/handlers"
+ "github.com/gorilla/mux"
+ "github.com/gorilla/sessions"
+ "github.com/nsheridan/cashier/lib"
+ "github.com/nsheridan/cashier/server/auth"
+ "github.com/nsheridan/cashier/server/config"
+ "github.com/nsheridan/cashier/server/static"
+ "github.com/nsheridan/cashier/server/templates"
+)
+
+// appContext contains local context - cookiestore, authsession etc.
+type appContext struct {
+ cookiestore *sessions.CookieStore
+ authsession *auth.Session
+}
+
+// getAuthTokenCookie retrieves a cookie from the request.
+func (a *appContext) getAuthTokenCookie(r *http.Request) *oauth2.Token {
+ session, _ := a.cookiestore.Get(r, "session")
+ 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
+}
+
+// setAuthTokenCookie marshals the auth token and stores it as a cookie.
+func (a *appContext) setAuthTokenCookie(w http.ResponseWriter, r *http.Request, t *oauth2.Token) {
+ session, _ := a.cookiestore.Get(r, "session")
+ val, _ := json.Marshal(t)
+ session.Values["token"] = val
+ session.Save(r, w)
+}
+
+// getAuthStateCookie retrieves the oauth csrf state value from the client request.
+func (a *appContext) getAuthStateCookie(r *http.Request) string {
+ session, _ := a.cookiestore.Get(r, "session")
+ state, ok := session.Values["state"]
+ if !ok {
+ return ""
+ }
+ return state.(string)
+}
+
+// setAuthStateCookie saves the oauth csrf state value.
+func (a *appContext) setAuthStateCookie(w http.ResponseWriter, r *http.Request, state string) {
+ session, _ := a.cookiestore.Get(r, "session")
+ session.Values["state"] = state
+ session.Save(r, w)
+}
+
+func (a *appContext) getCurrentURL(r *http.Request) string {
+ session, _ := a.cookiestore.Get(r, "session")
+ path, ok := session.Values["auth_url"]
+ if !ok {
+ return ""
+ }
+ return path.(string)
+}
+
+func (a *appContext) setCurrentURL(w http.ResponseWriter, r *http.Request) {
+ session, _ := a.cookiestore.Get(r, "session")
+ session.Values["auth_url"] = r.URL.Path
+ session.Save(r, w)
+}
+
+func (a *appContext) isLoggedIn(w http.ResponseWriter, r *http.Request) bool {
+ tok := a.getAuthTokenCookie(r)
+ if !tok.Valid() || !authprovider.Valid(tok) {
+ return false
+ }
+ return true
+}
+
+func (a *appContext) login(w http.ResponseWriter, r *http.Request) (int, error) {
+ a.setCurrentURL(w, r)
+ http.Redirect(w, r, "/auth/login", http.StatusSeeOther)
+ return http.StatusSeeOther, nil
+}
+
+// parseKey retrieves and unmarshals the signing request.
+func extractKey(r *http.Request) (*lib.SignRequest, error) {
+ var s lib.SignRequest
+ if err := json.NewDecoder(r.Body).Decode(&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,
+ }
+ if !authprovider.Valid(token) {
+ return http.StatusUnauthorized, errors.New(http.StatusText(http.StatusUnauthorized))
+ }
+
+ // Sign the pubkey and issue the cert.
+ req, err := extractKey(r)
+ if err != nil {
+ return http.StatusBadRequest, errors.Wrap(err, "unable to extract key from request")
+ }
+ username := authprovider.Username(token)
+ authprovider.Revoke(token) // We don't need this anymore.
+ cert, err := keysigner.SignUserKey(req, username)
+ if err != nil {
+ return http.StatusInternalServerError, errors.Wrap(err, "error signing key")
+ }
+ if err := certstore.SetCert(cert); err != nil {
+ log.Printf("Error recording cert: %v", err)
+ }
+ if err := json.NewEncoder(w).Encode(&lib.SignResponse{
+ Status: "ok",
+ Response: string(lib.GetPublicKey(cert)),
+ }); err != nil {
+ return http.StatusInternalServerError, errors.Wrap(err, "error encoding response")
+ }
+ return http.StatusOK, nil
+}
+
+// loginHandler starts the authentication process with the provider.
+func loginHandler(a *appContext, w http.ResponseWriter, r *http.Request) (int, error) {
+ state := newState()
+ a.setAuthStateCookie(w, r, state)
+ a.authsession = authprovider.StartSession(state)
+ 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.getAuthStateCookie(r) {
+ return http.StatusUnauthorized, errors.New(http.StatusText(http.StatusUnauthorized))
+ }
+ code := r.FormValue("code")
+ if err := a.authsession.Authorize(authprovider, code); err != nil {
+ return http.StatusInternalServerError, err
+ }
+ a.setAuthTokenCookie(w, r, a.authsession.Token)
+ http.Redirect(w, r, a.getCurrentURL(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) {
+ if !a.isLoggedIn(w, r) {
+ return a.login(w, r)
+ }
+ tok := a.getAuthTokenCookie(r)
+ page := struct {
+ Token string
+ }{tok.AccessToken}
+
+ tmpl := template.Must(template.New("token.html").Parse(templates.Token))
+ tmpl.Execute(w, page)
+ return http.StatusOK, nil
+}
+
+func listRevokedCertsHandler(a *appContext, w http.ResponseWriter, r *http.Request) (int, error) {
+ revoked, err := certstore.GetRevoked()
+ if err != nil {
+ return http.StatusInternalServerError, err
+ }
+ rl, err := keysigner.GenerateRevocationList(revoked)
+ if err != nil {
+ return http.StatusInternalServerError, errors.Wrap(err, "unable to generate KRL")
+ }
+ w.Header().Set("Content-Type", "application/octet-stream")
+ w.Write(rl)
+ return http.StatusOK, nil
+}
+
+func listAllCertsHandler(a *appContext, w http.ResponseWriter, r *http.Request) (int, error) {
+ if !a.isLoggedIn(w, r) {
+ return a.login(w, r)
+ }
+ tmpl := template.Must(template.New("certs.html").Parse(templates.Certs))
+ tmpl.Execute(w, map[string]interface{}{
+ csrf.TemplateTag: csrf.TemplateField(r),
+ })
+ return http.StatusOK, nil
+}
+
+func listCertsJSONHandler(a *appContext, w http.ResponseWriter, r *http.Request) (int, error) {
+ if !a.isLoggedIn(w, r) {
+ return http.StatusUnauthorized, errors.New(http.StatusText(http.StatusUnauthorized))
+ }
+ includeExpired, _ := strconv.ParseBool(r.URL.Query().Get("all"))
+ certs, err := certstore.List(includeExpired)
+ j, err := json.Marshal(certs)
+ if err != nil {
+ return http.StatusInternalServerError, errors.New(http.StatusText(http.StatusInternalServerError))
+ }
+ w.Write(j)
+ return http.StatusOK, nil
+}
+
+func revokeCertHandler(a *appContext, w http.ResponseWriter, r *http.Request) (int, error) {
+ if !a.isLoggedIn(w, r) {
+ return a.login(w, r)
+ }
+ r.ParseForm()
+ for _, id := range r.Form["cert_id"] {
+ if err := certstore.Revoke(id); err != nil {
+ return http.StatusInternalServerError, errors.Wrap(err, "unable to revoke")
+ }
+ }
+ http.Redirect(w, r, "/admin/certs", http.StatusSeeOther)
+ return http.StatusSeeOther, 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)
+ http.Error(w, err.Error(), 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 runHTTPServer(conf *config.Server, l net.Listener) {
+ var err error
+ ctx := &appContext{
+ cookiestore: sessions.NewCookieStore([]byte(conf.CookieSecret)),
+ }
+ ctx.cookiestore.Options = &sessions.Options{
+ MaxAge: 900,
+ Path: "/",
+ Secure: conf.UseTLS,
+ HttpOnly: true,
+ }
+
+ logfile := os.Stderr
+ if conf.HTTPLogFile != "" {
+ logfile, err = os.OpenFile(conf.HTTPLogFile, os.O_WRONLY|os.O_APPEND|os.O_CREATE, 0640)
+ if err != nil {
+ log.Printf("unable to open %s for writing. logging to stdout", conf.HTTPLogFile)
+ logfile = os.Stderr
+ }
+ }
+
+ CSRF := csrf.Protect([]byte(conf.CSRFSecret), csrf.Secure(conf.UseTLS))
+ r := mux.NewRouter()
+ r.Methods("GET").Path("/").Handler(appHandler{ctx, rootHandler})
+ r.Methods("GET").Path("/auth/login").Handler(appHandler{ctx, loginHandler})
+ r.Methods("GET").Path("/auth/callback").Handler(appHandler{ctx, callbackHandler})
+ r.Methods("POST").Path("/sign").Handler(appHandler{ctx, signHandler})
+ r.Methods("GET").Path("/revoked").Handler(appHandler{ctx, listRevokedCertsHandler})
+ r.Methods("POST").Path("/admin/revoke").Handler(CSRF(appHandler{ctx, revokeCertHandler}))
+ r.Methods("GET").Path("/admin/certs").Handler(CSRF(appHandler{ctx, listAllCertsHandler}))
+ r.Methods("GET").Path("/admin/certs.json").Handler(appHandler{ctx, listCertsJSONHandler})
+ r.Methods("GET").Path("/metrics").Handler(promhttp.Handler())
+ r.PathPrefix("/").Handler(http.FileServer(static.FS(false)))
+ h := handlers.LoggingHandler(logfile, r)
+ s := &http.Server{
+ Handler: h,
+ }
+ s.Serve(l)
+}