support changing wallet password

src/wallet/monero_wallet.h

@@ -1328,10 +1328,13 @@ namespace monero {
     }
 
     /**
-     * Save the wallet at its current path.
+     * Change the wallet password.
+     *
+     * @param old_password is the wallet's old password
+     * @param new_password is the wallet's new password
      */
-    virtual void save() {
-      throw std::runtime_error("save() not supported");
+    virtual void change_password(const std::string& old_password, const std::string& new_password) {
+      throw std::runtime_error("change_password() not supported");
     }
 
     /**
@@ -1340,10 +1343,17 @@ namespace monero {
      * @param path is the new wallet's path
      * @param password is the new wallet's password
      */
-    virtual void move_to(std::string path, std::string password) {
+    virtual void move_to(const std::string& path, const std::string& password) {
       throw std::runtime_error("move_to() not supported");
     }
 
+    /**
+     * Save the wallet at its current path.
+     */
+    virtual void save() {
+      throw std::runtime_error("save() not supported");
+    }
+
     /**
      * Optionally save then close the wallet.
      *

src/wallet/monero_wallet_full.cpp

@@ -3312,16 +3312,24 @@ namespace monero {
     return tx_hashes;
   }
 
+  void monero_wallet_full::change_password(const std::string& old_password, const std::string& new_password) {
+    MTRACE("change_password(" << "***" << ", ***)");
+    #if !defined(__EMSCRIPTEN__) // TODO: wallet2 verify_password loads from disk so password is verified in js for wasm
+      if (!m_w2->verify_password(old_password)) throw std::runtime_error("Invalid original password.");
+    #endif
+    m_w2->change_password(m_w2->get_wallet_file(), old_password, new_password);
+  }
+
+  void monero_wallet_full::move_to(const std::string& path, const std::string& password) {
+    MTRACE("move_to(" << path << ", ***)");
+    m_w2->store_to(path, password);
+  }
+
   void monero_wallet_full::save() {
     MTRACE("save()");
     m_w2->store();
   }
 
-  void monero_wallet_full::move_to(std::string path, std::string password) {
-    MTRACE("move_to(" << path << ", ***)");
-    m_w2->store_to(path, password);
-  }
-
   std::string monero_wallet_full::get_keys_file_buffer(const epee::wipeable_string& password, bool view_only) const {
     boost::optional<wallet2::keys_file_data> keys_file_data = m_w2->get_keys_file_data(password, view_only);
     std::string buf;

src/wallet/monero_wallet_full.h

@@ -274,8 +274,9 @@ namespace monero {
     int import_multisig_hex(const std::vector<std::string>& multisig_hexes) override;
     monero_multisig_sign_result sign_multisig_tx_hex(const std::string& multisig_tx_hex) override;
     std::vector<std::string> submit_multisig_tx_hex(const std::string& signed_multisig_tx_hex) override;
+    void change_password(const std::string& old_password, const std::string& new_password) override;
+    void move_to(const std::string& path, const std::string& password) override;
     void save() override;
-    void move_to(std::string path, std::string password) override;
     void close(bool save = false) override;
 
     /**