Initial commit

Created from https://vercel.com/new

1 files changed, 31 insertions, 0 deletions

diff --git a/pkg/encoding.ts b/pkg/encoding.ts
new file mode 100644
index 0000000..2025133
--- /dev/null
+++ b/pkg/encoding.ts
@@ -0,0 +1,31 @@
+import { fromBase58, toBase58 } from "../util/base58";
+import { ID_LENGTH, ENCRYPTION_KEY_LENGTH } from "./constants";
+/**
+ * To share links easily, we encode the id, where the data is stored in redis, together with the secret encryption key.
+ */
+export function encodeCompositeKey(version: number, id: string, encryptionKey: Uint8Array): string {
+  if (version < 0 || version > 255) {
+    throw new Error("Version must fit in a byte");
+  }
+  const compositeKey = new Uint8Array([version, ...fromBase58(id), ...encryptionKey]);
+
+  return toBase58(compositeKey);
+}
+
+/**
+ * To share links easily, we encode the id, where the data is stored in redis, together with the secret encryption key.
+ */
+export function decodeCompositeKey(compositeKey: string): { id: string; encryptionKey: Uint8Array; version: number } {
+  const decoded = fromBase58(compositeKey);
+  const version = decoded.at(0);
+
+  if (version === 1 || version === 2) {
+    return {
+      id: toBase58(decoded.slice(1, 1 + ID_LENGTH)),
+      encryptionKey: decoded.slice(1 + ID_LENGTH, 1 + ID_LENGTH + ENCRYPTION_KEY_LENGTH),
+      version,
+    };
+  }
+
+  throw new Error(`Unsupported composite key version: ${version}`);
+}