Changed auth to take into account not only the credentials,

but the requested operation/action too.

This allows to restrict vivify credentials to only upload
(as well as get and stat, because they're needed) to the
blobserver.

Change-Id: Idaed60d1f0d679cb9795ba9a11f094f964774335

cmd/camput/files.go

@@ -61,7 +61,6 @@ func init() {
 		cmd := new(fileCmd)
 		flags.BoolVar(&cmd.makePermanode, "permanode", false, "Create an associate a new permanode for the uploaded file or directory.")
 		flags.BoolVar(&cmd.filePermanodes, "filenodes", false, "Create (if necessary) content-based permanodes for each uploaded file.")
-		// TODO(mpl): check against possibly conflicting flags
 		flags.BoolVar(&cmd.vivify, "vivify", false,
 			"If true, ask the server to create and sign permanode(s) associated with each uploaded"+
 				" file. This permits the server to have your signing key. Used mostly with untrusted"+
@@ -103,6 +102,11 @@ func (c *fileCmd) RunCommand(up *Uploader, args []string) error {
 	if len(args) == 0 {
 		return UsageError("No files or directories given.")
 	}
+	if c.vivify {
+		if c.makePermanode || c.filePermanodes || c.tag != "" || c.name != "" {
+			return UsageError("--vivify excludes any other option")
+		}
+	}
 	if c.name != "" && !c.makePermanode {
 		return UsageError("Can't set name without using --permanode")
 	}
@@ -133,6 +137,12 @@ func (c *fileCmd) RunCommand(up *Uploader, args []string) error {
 			}
 		}
 	}
+	if c.makePermanode || c.filePermanodes {
+		testSigBlobRef := up.Client.SignerPublicKeyBlobref()
+		if testSigBlobRef == nil {
+			return UsageError("A gpg key is needed to create permanodes; configure one or use vivify mode.")
+		}
+	}
 	up.fileOpts = &fileOptions{permanode: c.filePermanodes, tag: c.tag, vivify: c.vivify}
 
 	var (
@@ -178,6 +188,10 @@ func (c *fileCmd) RunCommand(up *Uploader, args []string) error {
 			return err
 		}
 		if fi.IsDir() {
+			if up.fileOpts.wantVivify() {
+				vlog.Printf("Directories not supported in vivify mode; skipping %v\n", filename)
+				continue
+			}
 			t := up.NewTreeUpload(filename)
 			t.Start()
 			lastPut, err = t.Wait()

pkg/auth/auth.go

@@ -29,6 +29,21 @@ import (
 	"camlistore.org/pkg/netutil"
 )
 
+// Operation represents a bitmask of operations. See the OpX constants.
+type Operation int
+
+const (
+	OpUpload Operation = 1 << iota
+	OpStat
+	OpGet
+	OpEnumerate
+	OpRemove
+	OpRead   = OpEnumerate | OpStat | OpGet
+	OpRW     = OpUpload | OpEnumerate | OpStat | OpGet // Not Remove
+	OpVivify = OpUpload | OpStat | OpGet
+	OpAll    = OpUpload | OpEnumerate | OpStat | OpRemove | OpGet
+)
+
 var kBasicAuthPattern *regexp.Regexp = regexp.MustCompile(`^Basic ([a-zA-Z0-9\+/=]+)`)
 
 var (
@@ -36,8 +51,9 @@ var (
 )
 
 type AuthMode interface {
-	// IsAuthorized checks the credentials in req.
-	IsAuthorized(req *http.Request) bool
+	// AllowedAccess returns a bitmask of all operations
+	// this user/request is allowed to do.
+	AllowedAccess(req *http.Request) Operation
 	// AddAuthHeader inserts in req the credentials needed
 	// for a client to authenticate.
 	AddAuthHeader(req *http.Request)
@@ -60,7 +76,8 @@ func FromConfig(authConfig string) (AuthMode, error) {
 	authType := pieces[0]
 
 	if pw := os.Getenv("CAMLI_ADVERTISED_PASSWORD"); pw != "" {
-		mode = &DevAuth{pw}
+		// the vivify mode password is automatically set to "vivi" + Password
+		mode = &DevAuth{pw, "vivi" + pw}
 		return mode, nil
 	}
 
@@ -77,9 +94,12 @@ func FromConfig(authConfig string) (AuthMode, error) {
 		password := pieces[2]
 		mode = &UserPass{Username: username, Password: password}
 		for _, opt := range pieces[3:] {
-			switch opt {
-			case "+localhost":
+			switch {
+			case opt == "+localhost":
 				mode.(*UserPass).OrLocalhost = true
+			case strings.HasPrefix(opt, "vivify="):
+				// optional vivify mode password: "userpass:joe:ponies:vivify=rainbowdash"
+				mode.(*UserPass).VivifyPass = strings.Replace(opt, "vivify=", "", -1)
 			default:
 				return nil, fmt.Errorf("Unknown userpass option %q", opt)
 			}
@@ -115,20 +135,35 @@ func basicAuth(req *http.Request) (string, string, error) {
 
 // UserPass is used when the auth string provided in the config
 // is of the kind "userpass:username:pass"
+// Possible options appended to the config string are
+// "+localhost" and "vivify=pass", where pass will be the
+// alternative password which only allows the vivify operation.
 type UserPass struct {
 	Username, Password string
 	OrLocalhost        bool // if true, allow localhost ident auth too
+	// Alternative password used (only) for the vivify operation.
+	// It is checked when uploading, but Password takes precedence.
+	VivifyPass string
 }
 
-func (up *UserPass) IsAuthorized(req *http.Request) bool {
+func (up *UserPass) AllowedAccess(req *http.Request) Operation {
 	if up.OrLocalhost && localhostAuthorized(req) {
-		return true
+		return OpAll
 	}
+
 	user, pass, err := basicAuth(req)
 	if err != nil {
-		return false
+		return 0
 	}
-	return user == up.Username && pass == up.Password
+	if user == up.Username {
+		if pass == up.Password {
+			return OpAll
+		}
+		if pass == up.VivifyPass {
+			return OpVivify
+		}
+	}
+	return 0
 }
 
 func (up *UserPass) AddAuthHeader(req *http.Request) {
@@ -137,26 +172,55 @@ func (up *UserPass) AddAuthHeader(req *http.Request) {
 
 type None struct{}
 
-func (None) IsAuthorized(req *http.Request) bool {
-	return true
-}
-
-type Localhost struct {
-	None
-}
-
-func (Localhost) IsAuthorized(req *http.Request) bool {
-	return localhostAuthorized(req)
+func (None) AllowedAccess(req *http.Request) Operation {
+	return OpAll
 }
 
 func (None) AddAuthHeader(req *http.Request) {
 	// Nothing.
 }
 
+type Localhost struct {
+	None
+}
+
+func (Localhost) AllowedAccess(req *http.Request) Operation {
+	if localhostAuthorized(req) {
+		return OpAll
+	}
+	return 0
+}
+
 // DevAuth is used when the env var CAMLI_ADVERTISED_PASSWORD
 // is defined
 type DevAuth struct {
 	Password string
+	// Password for the vivify mode, automatically set to "vivi" + Password
+	VivifyPass string
+}
+
+func (da *DevAuth) AllowedAccess(req *http.Request) Operation {
+	// First see if the local TCP port is owned by the same
+	// non-root user as this server.
+	if localhostAuthorized(req) {
+		return OpAll
+	}
+
+	_, pass, err := basicAuth(req)
+	if err != nil {
+		return 0
+	}
+	if pass == da.Password {
+		return OpAll
+	}
+	if pass == da.VivifyPass {
+		return OpVivify
+	}
+	return 0
+}
+
+func (da *DevAuth) AddAuthHeader(req *http.Request) {
+	req.SetBasicAuth("", da.Password)
 }
 
 func localhostAuthorized(req *http.Request) bool {
@@ -196,30 +260,21 @@ func isLocalhost(addrPort net.IP) bool {
 	return addrPort.IsLoopback()
 }
 
-func LocalhostAuthorized(req *http.Request) bool {
+func IsLocalhost(req *http.Request) bool {
 	return localhostAuthorized(req)
 }
 
-func (da *DevAuth) IsAuthorized(req *http.Request) bool {
-	// First see if the local TCP port is owned by the same
-	// non-root user as this server.
-	if localhostAuthorized(req) {
-		return true
+// TODO(mpl): if/when we ever need it:
+// func AllowedWithAuth(am AuthMode, req *http.Request, op Operation) bool
+
+// Allowed returns whether the given request
+// has access to perform all the operations in op.
+func Allowed(req *http.Request, op Operation) bool {
+	if op|OpUpload != 0 {
+		// upload (at least from camput) requires stat and get too
+		op = op | OpVivify
 	}
-
-	_, pass, err := basicAuth(req)
-	if err != nil {
-		return false
-	}
-	return pass == da.Password
-}
-
-func (da *DevAuth) AddAuthHeader(req *http.Request) {
-	req.SetBasicAuth("", da.Password)
-}
-
-func IsAuthorized(req *http.Request) bool {
-	return mode.IsAuthorized(req)
+	return mode.AllowedAccess(req)&op == op
 }
 
 func TriedAuthorization(req *http.Request) bool {
@@ -242,8 +297,14 @@ type Handler struct {
 	http.Handler
 }
 
+// ServeHTTP serves only if this request and auth mode are allowed all Operations.
 func (h Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
-	if mode.IsAuthorized(r) {
+	h.serveHTTPForOp(w, r, OpAll)
+}
+
+// serveHTTPForOp serves only if op is allowed for this request and auth mode.
+func (h Handler) serveHTTPForOp(w http.ResponseWriter, r *http.Request, op Operation) {
+	if Allowed(r, op) {
 		h.Handler.ServeHTTP(w, r)
 	} else {
 		SendUnauthorized(w)
@@ -251,10 +312,10 @@ func (h Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 }
 
 // requireAuth wraps a function with another function that enforces
-// HTTP Basic Auth.
-func RequireAuth(handler func(conn http.ResponseWriter, req *http.Request)) func(conn http.ResponseWriter, req *http.Request) {
+// HTTP Basic Auth and checks if the operations in op are all permitted.
+func RequireAuth(handler func(conn http.ResponseWriter, req *http.Request), op Operation) func(conn http.ResponseWriter, req *http.Request) {
 	return func(conn http.ResponseWriter, req *http.Request) {
-		if mode.IsAuthorized(req) {
+		if Allowed(req, op) {
 			handler(conn, req)
 		} else {
 			SendUnauthorized(conn)

pkg/blobserver/gethandler/get.go

@@ -69,7 +69,7 @@ func (h *Handler) ServeHTTP(conn http.ResponseWriter, req *http.Request) {
 	}
 
 	switch {
-	case h.AllowGlobalAccess || auth.IsAuthorized(req):
+	case h.AllowGlobalAccess || auth.Allowed(req, auth.OpGet):
 		serveBlobRef(conn, req, blobRef, h.Fetcher)
 	case auth.TriedAuthorization(req):
 		log.Printf("Attempted authorization failed on %s", req.URL)

pkg/httputil/httputil.go

@@ -54,7 +54,7 @@ func RequestEntityTooLargeError(conn http.ResponseWriter) {
 
 func ServerError(conn http.ResponseWriter, req *http.Request, err error) {
 	conn.WriteHeader(http.StatusInternalServerError)
-	if auth.LocalhostAuthorized(req) {
+	if auth.IsLocalhost(req) {
 		fmt.Fprintf(conn, "Server error: %s\n", err)
 		return
 	}

pkg/server/root.go

@@ -89,7 +89,9 @@ func (rh *RootHandler) registerUIHandler(h *UIHandler) {
 
 func (rh *RootHandler) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 	if wantsDiscovery(req) {
-		if auth.IsAuthorized(req) {
+		// TODO(mpl): an OpDiscovery would be more to the point,
+		//  but OpGet is similar/good enough for now.
+		if auth.Allowed(req, auth.OpGet) {
 			rh.serveDiscovery(rw, req)
 			return
 		}
@@ -104,7 +106,7 @@ func (rh *RootHandler) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 	}
 
 	configLink := ""
-	if auth.LocalhostAuthorized(req) {
+	if auth.IsLocalhost(req) {
 		configLink = "<p>If you're coming from localhost, hit <a href='/setup'>/setup</a>.</p>"
 	}
 	fmt.Fprintf(rw, "<html><body>This is camlistored, a "+

pkg/server/wizard.go

@@ -246,7 +246,7 @@ func handleSetupChange(rw http.ResponseWriter, req *http.Request) {
 }
 
 func (sh *SetupHandler) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
-	if !auth.LocalhostAuthorized(req) {
+	if !auth.IsLocalhost(req) {
 		fmt.Fprintf(rw,
 			"<html><body>Setup only allowed from localhost"+
 				"<p><a href='/'>Back</a></p>"+

pkg/serverconfig/serverconfig.go

@@ -113,23 +113,24 @@ func handleCamliUsingStorage(conn http.ResponseWriter, req *http.Request, action
 	case "GET":
 		switch action {
 		case "enumerate-blobs":
-			handler = auth.RequireAuth(handlers.CreateEnumerateHandler(storage))
+			handler = auth.RequireAuth(handlers.CreateEnumerateHandler(storage), auth.OpGet)
 		case "stat":
-			handler = auth.RequireAuth(handlers.CreateStatHandler(storage))
+			handler = auth.RequireAuth(handlers.CreateStatHandler(storage), auth.OpAll)
 		default:
 			handler = gethandler.CreateGetHandler(storage)
 		}
 	case "POST":
 		switch action {
 		case "stat":
-			handler = auth.RequireAuth(handlers.CreateStatHandler(storage))
+			handler = auth.RequireAuth(handlers.CreateStatHandler(storage), auth.OpStat)
 		case "upload":
-			handler = auth.RequireAuth(handlers.CreateUploadHandler(storage))
+			handler = auth.RequireAuth(handlers.CreateUploadHandler(storage), auth.OpUpload)
 		case "remove":
-			handler = auth.RequireAuth(handlers.CreateRemoveHandler(storage))
+			handler = auth.RequireAuth(handlers.CreateRemoveHandler(storage), auth.OpAll)
 		}
+	// TODO: delete. Replaced with upload helper endpoint.
 	case "PUT": // no longer part of spec
-		handler = auth.RequireAuth(handlers.CreateNonStandardPutHandler(storage))
+		handler = auth.RequireAuth(handlers.CreateNonStandardPutHandler(storage), auth.OpAll)
 	}
 	handler(conn, req)
 }