optional encrypted key

Dockerfile

@@ -1,15 +1,15 @@
-FROM php:7.2-cli
+FROM php:7.4-cli
 
 RUN apt-get update && apt-get install -y libdb5.3++-dev
 
-RUN curl -O --referer https://fossies.org/linux/misc/db-18.1.25.tar.gz/ \
-        https://fossies.org/linux/misc/db-18.1.25.tar.gz \
-    && tar -zxf db-18.1.25.tar.gz && cd db-18.1.25/lang/php_db4/ \
+RUN curl -O --referer https://fossies.org/linux/misc/db-18.1.40.tar.gz/ \
+        https://fossies.org/linux/misc/db-18.1.40.tar.gz \
+    && tar -zxf db-18.1.40.tar.gz && cd db-18.1.40/lang/php_db4/ \
     && phpize \
     && ./configure --with-db4 \
     && make \
     && make install \
     && docker-php-ext-enable db4
 
-RUN apt-get install libgmp-dev \
+RUN apt-get install -y libgmp-dev \
     && docker-php-ext-install gmp

src/Item/MasterKey.php

@@ -68,14 +68,13 @@ public function getDerivationIterations(): int
 
     /**
      * Returns master key hash for hashcat.
-     * @param EncryptedKey $encryptedKey
+     * @param EncryptedKey|null $encryptedKey
      * @return string
-     * @throws \AndKom\Bitcoin\Wallet\Exception
      */
-    public function getHash(EncryptedKey $encryptedKey): string
+    public function getHash(EncryptedKey $encryptedKey = null): string
     {
-        $encrypted = bin2hex($encryptedKey->getEncryptedPrivateKey());
-        $public = bin2hex($encryptedKey->getPublicKey());
+        $encrypted = $encryptedKey ? bin2hex($encryptedKey->getEncryptedPrivateKey()) : '00';
+        $public = $encryptedKey ? bin2hex($encryptedKey->getPublicKey()) : '00';
         $master = substr(bin2hex($this->getEncryptedKey()), -64); // last two aes blocks should be enough
         $salt = bin2hex($this->getSalt());
 

tests/WalletTest.php

@@ -36,6 +36,7 @@ public function testMasterKey()
         $this->assertEquals($mk->getDerivationMethod(), 0);
         $this->assertEquals($mk->getDerivationIterations(), 196349);
         $this->assertEquals($mk->getHash($key), '$bitcoin$64$681a195c345695c6e87396eb7f8aefbf4e098ed009a42a173bd6db863c24d464$16$98313fb978e6ef49$196349$96$efe4244d839af470418ee08b278ffd20510dcd105bd1aa3de016bf59c35f99b8537222a0e4a8ea1db2b6b795de697785$66$03f4c3e512b84d950cf7568966a89c9048526076a2654c907a43db8fb8f38db508');
+        $this->assertEquals($mk->getHash(), '$bitcoin$64$681a195c345695c6e87396eb7f8aefbf4e098ed009a42a173bd6db863c24d464$16$98313fb978e6ef49$196349$2$00$2$00');
     }
 
     public function testDecrypt()