Enable attester selections from the request

README.md

@@ -53,3 +53,24 @@ Ratsd currently supports the Trusted Secure Module `tsm` attester. You can speci
 ```bash
 curl -X POST http://localhost:8895/ratsd/chares -H "Content-type: application/vnd.veraison.chares+json" -d '{"nonce": "TUlEQk5IMjhpaW9pc2pQeXh4eHh4eHh4eHh4eHh4eHhNSURCTkgyOGlpb2lzalB5eHh4eHh4eHh4eHh4eHh4eA", tsm-report:{"privilege_level": "$level"}}' # Replace $level with a number from 0 to 3
 ```
+
+## Get evidence from the selected attester only
+
+If more than one leaf attesters present, ratsd adds the evidence generated by all attesters to the response of `/ratsd/chares`. To limit the output to the selected attester, add `list-options: selected` to config.yaml,
+ then specify the name of each attester along with the associated options in `attester-selection`. If the user does not wish to specify the attester-specific option, "$attester_name": "null" should be specified. The following is an example of the request:
+```
+"nonce": "base64urlencoded",
+
+"attester-selection": {
+  "attester-id-1": {
+    "param11name": "param11value",
+    "param12name": "param12value"
+  },
+  "attester-id-2": {
+    "param21name": "param21value"
+  },
+  "attester-id-3": null
+}
+```
+
+If `list-options` is not set, or if it's set to `all` in config.yaml, ratsd populates the EAT with CMW from all available attesters as the default behavior.

api/server.go

@@ -24,12 +24,14 @@ const (
 type Server struct {
 	logger  *zap.SugaredLogger
 	manager plugin.IManager
+	options string
 }
 
-func NewServer(logger *zap.SugaredLogger, manager plugin.IManager) *Server {
+func NewServer(logger *zap.SugaredLogger, manager plugin.IManager, options string) *Server {
 	return &Server{
 		logger:  logger,
 		manager: manager,
+		options: options,
 	}
 }
 
@@ -124,19 +126,28 @@ func (s *Server) RatsdChares(w http.ResponseWriter, r *http.Request, param Ratsd
 				Status: http.StatusBadRequest,
 			}
 			s.reportProblem(w, p)
-			fmt.Println(errMsg)
 			return
 		}
+	} else if s.options == "selected" {
+		errMsg := "attester-selection must contain at least one attester"
+		p := &problems.DefaultProblem{
+			Type:   string(TagGithubCom2024VeraisonratsdErrorInvalidrequest),
+			Title:  string(InvalidRequest),
+			Detail: errMsg,
+			Status: http.StatusBadRequest,
+		}
+		s.reportProblem(w, p)
+		return
 	}
 
-	for _, pn := range pl {
+	getCMW := func (pn string) bool {
 		attester, err := s.manager.LookupByName(pn)
 		if err != nil {
 			errMsg := fmt.Sprintf(
 				"failed to get handle from %s: %s", pn, err.Error())
 			p := problems.NewDetailedProblem(http.StatusInternalServerError, errMsg)
 			s.reportProblem(w, p)
-			return
+			return false
 		}
 
 		formatOut := attester.GetSupportedFormats()
@@ -145,11 +156,11 @@ func (s *Server) RatsdChares(w http.ResponseWriter, r *http.Request, param Ratsd
 				pn, formatOut.Status.Error)
 			p := problems.NewDetailedProblem(http.StatusInternalServerError, errMsg)
 			s.reportProblem(w, p)
-			return
+			return false
 		}
 
 		params, hasOption := options[pn]
-		if !hasOption {
+		if !hasOption || string(params) == "null" {
 			params = json.RawMessage{}
 		}
 
@@ -166,11 +177,26 @@ func (s *Server) RatsdChares(w http.ResponseWriter, r *http.Request, param Ratsd
 				"failed to get attestation report from %s: %s ", pn, out.Status.Error)
 			p := problems.NewDetailedProblem(http.StatusInternalServerError, errMsg)
 			s.reportProblem(w, p)
-			return
+			return false
 		}
 
 		c := cmw.NewMonad(in.ContentType, out.Evidence)
 		collection.AddCollectionItem(pn, c)
+		return true
+	}
+
+	if s.options == "all" {
+		for _, pn := range pl {
+			if !getCMW(pn) {
+				return
+			}
+		}
+	} else {
+		for pn, _ := range options {
+			if !getCMW(pn) {
+				return
+			}
+		}
 	}
 
 	serialized, err := collection.MarshalJSON()

api/server_test.go

@@ -89,12 +89,12 @@ func TestRatsdChares_invalid_body(t *testing.T) {
 	params.Accept = &param
 	logger := log.Named("test")
 
-	pluginList := []string{"mock-tsm"}
+	pluginList := []string{"mock-tsm", "tsm-report"}
 	dm := mock_deps.NewMockIManager(ctrl)
 	dm.EXPECT().GetPluginList().Return(pluginList).AnyTimes()
 	dm.EXPECT().LookupByName("mock-tsm").Return(mocktsm.GetPlugin(), nil).AnyTimes()
 
-	s := NewServer(logger, dm)
+	s := NewServer(logger, dm, "selected")
 	tests := []struct{ name, body, msg string }{
 		{"missing nonce", `{"noncee": "MIDBNH28iioisjPy"}`,
 			"fail to retrieve nonce from the request"},
@@ -103,6 +103,8 @@ func TestRatsdChares_invalid_body(t *testing.T) {
 		"attester-selection": "attester-slection"}`, validNonce),
 			"failed to parse attester selection: json: cannot unmarshal string into" +
 				` Go value of type map[string]json.RawMessage`},
+		{"no attester specified in selected mode", fmt.Sprintf(`{"nonce": "%s"}`, validNonce),
+			"attester-selection must contain at least one attester"},
 	}
 
 	for _, tt := range tests {
@@ -146,7 +148,7 @@ func TestRatsdChares_valid_request_no_available_attester(t *testing.T) {
 	dm := mock_deps.NewMockIManager(ctrl)
 	dm.EXPECT().GetPluginList().Return(pluginList)
 
-	s := NewServer(logger, dm)
+	s := NewServer(logger, dm, "all")
 	w := httptest.NewRecorder()
 	rs := fmt.Sprintf(`{"nonce": "%s"}`, validNonce)
 	rb := strings.NewReader(rs)
@@ -182,7 +184,7 @@ func TestRatsdChares_valid_request(t *testing.T) {
 	dm.EXPECT().GetPluginList().Return(pluginList).AnyTimes()
 	dm.EXPECT().LookupByName("mock-tsm").Return(mocktsm.GetPlugin(), nil).AnyTimes()
 
-	s := NewServer(logger, dm)
+	s := NewServer(logger, dm, "all")
 	realNonce, _ := base64.RawURLEncoding.DecodeString(validNonce)
 
 	tests := []struct {
@@ -194,6 +196,15 @@ func TestRatsdChares_valid_request(t *testing.T) {
 			fmt.Sprintf(`{"nonce": "%s"}`, validNonce),
 			0,
 		},
+		{
+			"with null as params",
+			fmt.Sprintf(`{"nonce": "%s",
+				"attester-selection":{
+					"mock-tsm": null
+				}
+			}`, validNonce),
+			0,
+		},
 		{
 			"with params",
 			fmt.Sprintf(`{"nonce": "%s",

cmd/main.go

@@ -18,11 +18,12 @@ var (
 )
 
 type cfg struct {
-	ListenAddr string `mapstructure:"listen-addr" valid:"dialstring"`
-	Protocol   string `mapstructure:"protocol" valid:"in(http|https)"`
-	Cert       string `mapstructure:"cert" config:"zerodefault"`
-	CertKey    string `mapstructure:"cert-key" config:"zerodefault"`
-	PluginDir  string `mapstructure:"plugin-dir" config:"zerodefault"`
+	ListenAddr  string `mapstructure:"listen-addr" valid:"dialstring"`
+	Protocol    string `mapstructure:"protocol" valid:"in(http|https)"`
+	Cert        string `mapstructure:"cert" config:"zerodefault"`
+	CertKey     string `mapstructure:"cert-key" config:"zerodefault"`
+	PluginDir   string `mapstructure:"plugin-dir" config:"zerodefault"`
+	ListOptions string `mapstructure:"list-options" valid:"in(all|selected)"`
 }
 
 func (o cfg) Validate() error {
@@ -84,7 +85,7 @@ func main() {
 
 	log.Info("Loaded sub-attesters:", pluginManager.GetPluginList())
 
-	svr := api.NewServer(log.Named("api"), pluginManager)
+	svr := api.NewServer(log.Named("api"), pluginManager, cfg.ListOptions)
 	r := http.NewServeMux()
 	options := api.StdHTTPServerOptions{
 		BaseRouter:  r,

config.yaml

@@ -4,3 +4,4 @@ ratsd:
   listen-addr: 0.0.0.0:8895
   protocol: http
   plugin-dir: attesters/bin
+  list-options: all