fix: properly decrypt legacy state blobs

MetaMask · Jun 10, 2024 · 4e3d119 · 4e3d119
1 parent 1bf7e4f
commit 4e3d119
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Showing 2 changed files with 45 additions and 1 deletion.
diff --git a/packages/snaps-controllers/src/snaps/SnapController.test.tsx b/packages/snaps-controllers/src/snaps/SnapController.test.tsx
@@ -78,6 +78,7 @@ import {
   getSnapControllerOptions,
   getSnapControllerWithEES,
   getSnapControllerWithEESOptions,
+  LEGACY_ENCRYPTION_KEY_DERIVATION_OPTIONS,
   loopbackDetect,
   LoopbackLocation,
   MOCK_BLOCK_NUMBER,
@@ -8178,6 +8179,42 @@ describe('SnapController', () => {
       snapController.destroy();
     });
 
+    it('uses legacy decryption where needed', async () => {
+      const messenger = getSnapControllerMessenger();
+
+      const state = { foo: 'bar' };
+
+      const { data, iv, salt } = JSON.parse(
+        await encrypt(
+          ENCRYPTION_KEY,
+          state,
+          undefined,
+          undefined,
+          LEGACY_ENCRYPTION_KEY_DERIVATION_OPTIONS,
+        ),
+      );
+
+      const snapController = getSnapController(
+        getSnapControllerOptions({
+          messenger,
+          state: {
+            snaps: {
+              [MOCK_SNAP_ID]: getPersistedSnapObject(),
+            },
+            snapStates: {
+              [MOCK_SNAP_ID]: JSON.stringify({ data, iv, salt }),
+            },
+          },
+        }),
+      );
+
+      expect(
+        await messenger.call('SnapController:getSnapState', MOCK_SNAP_ID, true),
+      ).toStrictEqual(state);
+
+      snapController.destroy();
+    });
+
     it('throws an error if the state is corrupt', async () => {
       const messenger = getSnapControllerMessenger();
 

diff --git a/packages/snaps-controllers/src/snaps/SnapController.ts b/packages/snaps-controllers/src/snaps/SnapController.ts
@@ -1676,7 +1676,14 @@ export class SnapController extends BaseController<
         snapId,
         salt,
         useCache,
-        keyMetadata,
+        // When decrypting state we expect key metadata to be present.
+        // If it isn't present, we assume that the Snap state we are decrypting is old enough to use the legacy encryption params.
+        keyMetadata: keyMetadata ?? {
+          algorithm: 'PBKDF2',
+          params: {
+            iterations: 10_000,
+          },
+        },
       });
       const decryptedState = await this.#encryptor.decryptWithKey(key, parsed);