Fix notary keys requests for all keys (#3296)

This should be more spec compliant:
> If no key IDs are given to be queried, the notary server should query
for all keys.

federationapi/federationapi_test.go

@@ -5,11 +5,14 @@ import (
 	"crypto/ed25519"
 	"encoding/json"
 	"fmt"
+	"net/http"
+	"net/http/httptest"
 	"strings"
 	"sync"
 	"testing"
 	"time"
 
+	"github.com/matrix-org/dendrite/federationapi/routing"
 	"github.com/matrix-org/dendrite/internal/caching"
 	"github.com/matrix-org/dendrite/internal/httputil"
 	"github.com/matrix-org/dendrite/internal/sqlutil"
@@ -17,7 +20,10 @@ import (
 	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/matrix-org/gomatrixserverlib/fclient"
 	"github.com/matrix-org/gomatrixserverlib/spec"
+	"github.com/matrix-org/util"
 	"github.com/nats-io/nats.go"
+	"github.com/stretchr/testify/assert"
+	"github.com/tidwall/gjson"
 
 	"github.com/matrix-org/dendrite/federationapi"
 	"github.com/matrix-org/dendrite/federationapi/api"
@@ -362,3 +368,126 @@ func TestRoomsV3URLEscapeDoNot404(t *testing.T) {
 		}
 	}
 }
+
+func TestNotaryServer(t *testing.T) {
+	testCases := []struct {
+		name          string
+		httpBody      string
+		pubKeyRequest *gomatrixserverlib.PublicKeyNotaryLookupRequest
+		validateFunc  func(t *testing.T, response util.JSONResponse)
+	}{
+		{
+			name: "empty httpBody",
+			validateFunc: func(t *testing.T, resp util.JSONResponse) {
+				assert.Equal(t, http.StatusBadRequest, resp.Code)
+				nk, ok := resp.JSON.(spec.MatrixError)
+				assert.True(t, ok)
+				assert.Equal(t, spec.ErrorBadJSON, nk.ErrCode)
+			},
+		},
+		{
+			name:     "valid but empty httpBody",
+			httpBody: "{}",
+			validateFunc: func(t *testing.T, resp util.JSONResponse) {
+				want := util.JSONResponse{
+					Code: http.StatusOK,
+					JSON: routing.NotaryKeysResponse{ServerKeys: []json.RawMessage{}},
+				}
+				assert.Equal(t, want, resp)
+			},
+		},
+		{
+			name:     "request all keys using an empty criteria",
+			httpBody: `{"server_keys":{"servera":{}}}`,
+			validateFunc: func(t *testing.T, resp util.JSONResponse) {
+				assert.Equal(t, http.StatusOK, resp.Code)
+				nk, ok := resp.JSON.(routing.NotaryKeysResponse)
+				assert.True(t, ok)
+				assert.Equal(t, "servera", gjson.GetBytes(nk.ServerKeys[0], "server_name").Str)
+				assert.True(t, gjson.GetBytes(nk.ServerKeys[0], "verify_keys.ed25519:someID").Exists())
+			},
+		},
+		{
+			name:     "request all keys using null as the criteria",
+			httpBody: `{"server_keys":{"servera":null}}`,
+			validateFunc: func(t *testing.T, resp util.JSONResponse) {
+				assert.Equal(t, http.StatusOK, resp.Code)
+				nk, ok := resp.JSON.(routing.NotaryKeysResponse)
+				assert.True(t, ok)
+				assert.Equal(t, "servera", gjson.GetBytes(nk.ServerKeys[0], "server_name").Str)
+				assert.True(t, gjson.GetBytes(nk.ServerKeys[0], "verify_keys.ed25519:someID").Exists())
+			},
+		},
+		{
+			name:     "request specific key",
+			httpBody: `{"server_keys":{"servera":{"ed25519:someID":{}}}}`,
+			validateFunc: func(t *testing.T, resp util.JSONResponse) {
+				assert.Equal(t, http.StatusOK, resp.Code)
+				nk, ok := resp.JSON.(routing.NotaryKeysResponse)
+				assert.True(t, ok)
+				assert.Equal(t, "servera", gjson.GetBytes(nk.ServerKeys[0], "server_name").Str)
+				assert.True(t, gjson.GetBytes(nk.ServerKeys[0], "verify_keys.ed25519:someID").Exists())
+			},
+		},
+		{
+			name:     "request multiple servers",
+			httpBody: `{"server_keys":{"servera":{"ed25519:someID":{}},"serverb":{"ed25519:someID":{}}}}`,
+			validateFunc: func(t *testing.T, resp util.JSONResponse) {
+				assert.Equal(t, http.StatusOK, resp.Code)
+				nk, ok := resp.JSON.(routing.NotaryKeysResponse)
+				assert.True(t, ok)
+				wantServers := map[string]struct{}{
+					"servera": {},
+					"serverb": {},
+				}
+				for _, js := range nk.ServerKeys {
+					serverName := gjson.GetBytes(js, "server_name").Str
+					_, ok = wantServers[serverName]
+					assert.True(t, ok, "unexpected servername: %s", serverName)
+					delete(wantServers, serverName)
+					assert.True(t, gjson.GetBytes(js, "verify_keys.ed25519:someID").Exists())
+				}
+				if len(wantServers) > 0 {
+					t.Fatalf("expected response to also contain: %#v", wantServers)
+				}
+			},
+		},
+	}
+
+	test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
+		cfg, processCtx, close := testrig.CreateConfig(t, dbType)
+		defer close()
+		cm := sqlutil.NewConnectionManager(processCtx, cfg.Global.DatabaseOptions)
+		caches := caching.NewRistrettoCache(128*1024*1024, time.Hour, caching.DisableMetrics)
+		natsInstance := jetstream.NATSInstance{}
+		fc := &fedClient{
+			keys: map[spec.ServerName]struct {
+				key   ed25519.PrivateKey
+				keyID gomatrixserverlib.KeyID
+			}{
+				"servera": {
+					key:   test.PrivateKeyA,
+					keyID: "ed25519:someID",
+				},
+				"serverb": {
+					key:   test.PrivateKeyB,
+					keyID: "ed25519:someID",
+				},
+			},
+		}
+
+		fedAPI := federationapi.NewInternalAPI(processCtx, cfg, cm, &natsInstance, fc, nil, caches, nil, true)
+
+		for _, tc := range testCases {
+			t.Run(tc.name, func(t *testing.T) {
+				req := httptest.NewRequest(http.MethodPost, "/", strings.NewReader(tc.httpBody))
+				req.Host = string(cfg.Global.ServerName)
+
+				resp := routing.NotaryKeys(req, &cfg.FederationAPI, fedAPI, tc.pubKeyRequest)
+				// assert that we received the expected response
+				tc.validateFunc(t, resp)
+			})
+		}
+
+	})
+}

federationapi/internal/query.go

@@ -43,6 +43,15 @@ func (a *FederationInternalAPI) fetchServerKeysFromCache(
 	ctx context.Context, req *api.QueryServerKeysRequest,
 ) ([]gomatrixserverlib.ServerKeys, error) {
 	var results []gomatrixserverlib.ServerKeys
+
+	// We got a request for _all_ server keys, return them.
+	if len(req.KeyIDToCriteria) == 0 {
+		serverKeysResponses, _ := a.db.GetNotaryKeys(ctx, req.ServerName, []gomatrixserverlib.KeyID{})
+		if len(serverKeysResponses) == 0 {
+			return nil, fmt.Errorf("failed to find server key response for server %s", req.ServerName)
+		}
+		return serverKeysResponses, nil
+	}
 	for keyID, criteria := range req.KeyIDToCriteria {
 		serverKeysResponses, _ := a.db.GetNotaryKeys(ctx, req.ServerName, []gomatrixserverlib.KeyID{keyID})
 		if len(serverKeysResponses) == 0 {

federationapi/routing/keys.go

@@ -197,6 +197,10 @@ func localKeys(cfg *config.FederationAPI, serverName spec.ServerName) (*gomatrix
 	return &keys, err
 }
 
+type NotaryKeysResponse struct {
+	ServerKeys []json.RawMessage `json:"server_keys"`
+}
+
 func NotaryKeys(
 	httpReq *http.Request, cfg *config.FederationAPI,
 	fsAPI federationAPI.FederationInternalAPI,
@@ -217,10 +221,9 @@ func NotaryKeys(
 		}
 	}
 
-	var response struct {
-		ServerKeys []json.RawMessage `json:"server_keys"`
+	response := NotaryKeysResponse{
+		ServerKeys: []json.RawMessage{},
 	}
-	response.ServerKeys = []json.RawMessage{}
 
 	for serverName, kidToCriteria := range req.ServerKeys {
 		var keyList []gomatrixserverlib.ServerKeys