refactor: encryptor to typescript

Author: gantunesr

app/core/Encryptor/Encryptor.ts

@@ -0,0 +1,133 @@
+import { NativeModules } from 'react-native';
+const Aes = NativeModules.Aes;
+const AesForked = NativeModules.AesForked;
+
+/**
+ * Class that exposes two public methods: Encrypt and Decrypt
+ * This is used by the KeyringController to encrypt / decrypt the state
+ * which contains sensitive seed words and addresses
+ */
+class Encryptor {
+  key = null;
+
+  _generateSalt(byteCount = 32) {
+    const view = new Uint8Array(byteCount);
+    global.crypto.getRandomValues(view);
+    const b64encoded = btoa(String.fromCharCode.apply(null, Array.from(view)));
+    return b64encoded;
+  }
+
+  _generateKey = ({
+    password,
+    salt,
+    lib,
+  }: {
+    password: string;
+    salt: string;
+    lib: string;
+  }) =>
+    lib === 'original'
+      ? Aes.pbkdf2(password, salt, 5000, 256)
+      : AesForked.pbkdf2(password, salt);
+
+  _keyFromPassword = ({
+    password,
+    salt,
+    lib,
+  }: {
+    password: string;
+    salt: string;
+    lib: string;
+  }) => this._generateKey({ password, salt, lib });
+
+  _encryptWithKey = async ({
+    text,
+    keyBase64,
+  }: {
+    text: string;
+    keyBase64: string;
+  }) => {
+    const iv = await Aes.randomKey(16);
+    return Aes.encrypt(text, keyBase64, iv).then((cipher: string) => ({
+      cipher,
+      iv,
+    }));
+  };
+
+  _decryptWithKey = ({
+    encryptedData,
+    key,
+    lib,
+  }: {
+    encryptedData: { cipher: string; iv: string };
+    key: string;
+    lib: string;
+  }) =>
+    lib === 'original'
+      ? Aes.decrypt(encryptedData.cipher, key, encryptedData.iv)
+      : AesForked.decrypt(encryptedData.cipher, key, encryptedData.iv);
+
+  /**
+   * Asynchronously encrypts a given object using AES encryption.
+   * The encryption process involves generating a salt, deriving a key from the provided password and salt,
+   * and then using the key to encrypt the object. The result includes the encrypted data, the salt used,
+   * and the library version ('original' in this case).
+   *
+   * @param params.password - The password used for generating the encryption key.
+   * @param params.object - The data object to encrypt. It can be of any type, as it will be stringified during the encryption process.
+   * @returns A promise that resolves to a string. The string is a JSON representation of an object containing the encrypted data, the salt used for encryption, and the library version.
+   */
+  encrypt = async ({
+    password,
+    object,
+  }: {
+    password: string;
+    object: unknown;
+  }): Promise<string> => {
+    const salt = this._generateSalt(16);
+    const key = await this._keyFromPassword({
+      password,
+      salt,
+      lib: 'original',
+    });
+    const result = await this._encryptWithKey({
+      text: JSON.stringify(object),
+      keyBase64: key,
+    });
+    result.salt = salt;
+    result.lib = 'original';
+    return JSON.stringify(result);
+  };
+
+  /**
+   * Decrypts an encrypted JS object (encryptedString)
+   * using a password (and AES decryption with native libraries)
+   *
+   * @param {string} password - Password used for decryption
+   * @param {string} encryptedString - String to decrypt
+   * @returns - Promise resolving to decrypted data object
+   */
+  decrypt = async ({
+    password,
+    encryptedString,
+  }: {
+    password: string;
+    encryptedString: string;
+  }) => {
+    const encryptedData = JSON.parse(encryptedString);
+    const key = await this._keyFromPassword({
+      password,
+      salt: encryptedData.salt,
+      lib: encryptedData.lib,
+    });
+    const data = await this._decryptWithKey({
+      encryptedData,
+      key,
+      lib: encryptedData.lib,
+    });
+    return JSON.parse(data);
+  };
+}
+
+// eslint-disable-next-line import/prefer-default-export
+export { Encryptor };

app/core/Encryptor/index.ts

@@ -0,0 +1,3 @@
+import { Encryptor } from './Encryptor';
+
+export default Encryptor;