unlock with PIN (#8977)

* add custom password to unlock settings

* If not set, use admin password; if set, use custom settings password.
* At least 4 characters.
* Set with gui or command line.

Signed-off-by: 21pages <sunboeasy@gmail.com>

* Update cn.rs

---------

Signed-off-by: 21pages <sunboeasy@gmail.com>
Co-authored-by: RustDesk <71636191+rustdesk@users.noreply.github.com>

libs/hbb_common/src/config.rs

@@ -208,6 +208,8 @@ pub struct Config2 {
     nat_type: i32,
     #[serde(default, deserialize_with = "deserialize_i32")]
     serial: i32,
+    #[serde(default, deserialize_with = "deserialize_string")]
+    unlock_pin: String,
 
     #[serde(default)]
     socks: Option<Socks5Server>,
@@ -427,14 +429,20 @@ fn patch(path: PathBuf) -> PathBuf {
 impl Config2 {
     fn load() -> Config2 {
         let mut config = Config::load_::<Config2>("2");
+        let mut store = false;
         if let Some(mut socks) = config.socks {
-            let (password, _, store) =
+            let (password, _, store2) =
                 decrypt_str_or_original(&socks.password, PASSWORD_ENC_VERSION);
             socks.password = password;
             config.socks = Some(socks);
-            if store {
-                config.store();
-            }
+            store |= store2;
+        }
+        let (unlock_pin, _, store2) =
+            decrypt_str_or_original(&config.unlock_pin, PASSWORD_ENC_VERSION);
+        config.unlock_pin = unlock_pin;
+        store |= store2;
+        if store {
+            config.store();
         }
         config
     }
@@ -450,6 +458,8 @@ impl Config2 {
                 encrypt_str_or_original(&socks.password, PASSWORD_ENC_VERSION, ENCRYPT_MAX_LEN);
             config.socks = Some(socks);
         }
+        config.unlock_pin =
+            encrypt_str_or_original(&config.unlock_pin, PASSWORD_ENC_VERSION, ENCRYPT_MAX_LEN);
         Config::store_(&config, "2");
     }
 
@@ -1081,6 +1091,19 @@ impl Config {
         NetworkType::Direct
     }
 
+    pub fn get_unlock_pin() -> String {
+        CONFIG2.read().unwrap().unlock_pin.clone()
+    }
+
+    pub fn set_unlock_pin(pin: &str) {
+        let mut config = CONFIG2.write().unwrap();
+        if pin == config.unlock_pin {
+            return;
+        }
+        config.unlock_pin = pin.to_string();
+        config.store();
+    }
+
     pub fn get() -> Config {
         return CONFIG.read().unwrap().clone();
     }