Implement logic for key uploads (#1197)

* begin work on storing keys

* Finish rough impl of the internal key API

* Linting

keyserver/storage/interface.go

@@ -0,0 +1,38 @@
+// Copyright 2020 The Matrix.org Foundation C.I.C.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package storage
+
+import (
+	"context"
+	"encoding/json"
+
+	"github.com/matrix-org/dendrite/keyserver/api"
+)
+
+type Database interface {
+	// ExistingOneTimeKeys returns a map of keyIDWithAlgorithm to key JSON for the given parameters. If no keys exist with this combination
+	// of user/device/key/algorithm 4-uple then it is omitted from the map. Returns an error when failing to communicate with the database.
+	ExistingOneTimeKeys(ctx context.Context, userID, deviceID string, keyIDsWithAlgorithms []string) (map[string]json.RawMessage, error)
+
+	// StoreOneTimeKeys persists the given one-time keys.
+	StoreOneTimeKeys(ctx context.Context, keys api.OneTimeKeys) error
+
+	// DeviceKeysJSON populates the KeyJSON for the given keys. If any proided `keys` have a `KeyJSON` already then it will be replaced.
+	DeviceKeysJSON(ctx context.Context, keys []api.DeviceKeys) error
+
+	// StoreDeviceKeys persists the given keys. Keys with the same user ID and device ID will be replaced.
+	// Returns an error if there was a problem storing the keys.
+	StoreDeviceKeys(ctx context.Context, keys []api.DeviceKeys) error
+}