add key derivation function

Author: matthiasgeihs

packages/keyring-controller/src/KeyringController.test.ts

@@ -816,6 +816,18 @@ describe('KeyringController', () => {
       );
     });
 
+    it('should create new vault with encryption key from key seed', async () => {
+      await withController(
+        { cacheEncryptionKey: true, skipVaultCreation: true },
+        async ({ controller }) => {
+          const key = await controller.deriveKeyFromSeed(password);
+          await controller.createNewVaultAndKeychain(password, key);
+          expect(controller.state.encryptionKey).toBeDefined();
+          expect(controller.state.encryptedEncryptionKey).toBeDefined();
+        },
+      );
+    });
+
     it('should throw error if creating new vault with encryption key and cacheEncryptionKey is false', async () => {
       await withController(
         { cacheEncryptionKey: false, skipVaultCreation: true },

packages/keyring-controller/src/KeyringController.ts

@@ -809,6 +809,21 @@ export class KeyringController extends BaseController<
     });
   }
 
+  /**
+   * Derives an encryption key from a key seed.
+   *
+   * @param keySeed - The key seed to derive the key from.
+   * @returns Promise resolving to the derived encryption key.
+   */
+  async deriveKeyFromSeed(keySeed: string): Promise<string> {
+    assertIsExportableKeyEncryptor(this.#encryptor);
+    const { exportedKeyString } = await this.#encryptor.encryptWithDetail(
+      keySeed,
+      null, // dummy value, we just want the key
+    );
+    return exportedKeyString;
+  }
+
   /**
    * Effectively the same as creating a new keychain then populating it
    * using the given seed phrase.