1 files changed, 41 insertions, 0 deletions
diff --git a/internal/caching/cache_serverkeys.go b/internal/caching/cache_serverkeys.go
new file mode 100644
index 00000000..8c71ffbd
--- /dev/null
+++ b/internal/caching/cache_serverkeys.go
@@ -0,0 +1,41 @@
+package caching
+
+import (
+	"fmt"
+
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+const (
+	ServerKeyCacheName       = "server_key"
+	ServerKeyCacheMaxEntries = 4096
+	ServerKeyCacheMutable    = true
+)
+
+// ServerKeyCache contains the subset of functions needed for
+// a server key cache.
+type ServerKeyCache interface {
+	GetServerKey(request gomatrixserverlib.PublicKeyLookupRequest) (response gomatrixserverlib.PublicKeyLookupResult, ok bool)
+	StoreServerKey(request gomatrixserverlib.PublicKeyLookupRequest, response gomatrixserverlib.PublicKeyLookupResult)
+}
+
+func (c Caches) GetServerKey(
+	request gomatrixserverlib.PublicKeyLookupRequest,
+) (gomatrixserverlib.PublicKeyLookupResult, bool) {
+	key := fmt.Sprintf("%s/%s", request.ServerName, request.KeyID)
+	val, found := c.ServerKeys.Get(key)
+	if found && val != nil {
+		if keyLookupResult, ok := val.(gomatrixserverlib.PublicKeyLookupResult); ok {
+			return keyLookupResult, true
+		}
+	}
+	return gomatrixserverlib.PublicKeyLookupResult{}, false
+}
+
+func (c Caches) StoreServerKey(
+	request gomatrixserverlib.PublicKeyLookupRequest,
+	response gomatrixserverlib.PublicKeyLookupResult,
+) {
+	key := fmt.Sprintf("%s/%s", request.ServerName, request.KeyID)
+	c.ServerKeys.Set(key, response)
+}