account_add: Better error handling

In the case where the token is not a valid Base32 string or the provider
was not found the ErrorRevealer widget is used.

Fixes: https://gitlab.gnome.org/World/Authenticator/-/issues/225

data/resources/ui/account_add.ui

@@ -85,6 +85,11 @@
                                 <property name="size">96</property>
                               </object>
                             </child>
+                            <child>
+                              <object class="ErrorRevealer" id="error_revealer">
+                                <property name="margin-top">12</property>
+                              </object>
+                            </child>
                             <child>
                               <object class="GtkListBox">
                                 <property name="selection-mode">none</property>

po/POTFILES.in

@@ -19,6 +19,7 @@ src/backup/bitwarden.rs
 src/backup/freeotp.rs
 src/backup/legacy.rs
 src/models/algorithm.rs
+src/widgets/accounts/add.rs
 src/widgets/window.rs
 src/widgets/preferences/password_page.rs
 src/widgets/preferences/window.rs

src/models/otp.rs

@@ -15,12 +15,17 @@ pub static TOTP_DEFAULT_PERIOD: u32 = 30;
 /// https://github.com/TimDumol/rust-otp/blob/master/src/lib.rs
 
 /// Decodes a secret (given as an RFC4648 base32-encoded ASCII string)
-/// into a byte string
+/// into a byte string. It fails if secret is not a valid Base32 string.
 fn decode_secret(secret: &str) -> Result<Vec<u8>> {
     let res = BASE32.decode(secret.as_bytes())?;
     Ok(res)
 }
 
+/// Validates if `secret` is a valid Base32 String.
+pub fn is_valid(secret: &str) -> bool {
+    decode_secret(secret).is_ok()
+}
+
 /// Calculates the HMAC digest for the given secret and counter.
 fn calc_digest(decoded_secret: &[u8], counter: u64, algorithm: hmac::Algorithm) -> hmac::Tag {
     let key = hmac::Key::new(algorithm, decoded_secret);

src/widgets/accounts/add.rs

@@ -1,8 +1,9 @@
 use crate::{
-    models::{Account, OTPMethod, OTPUri, Provider, ProvidersModel},
-    widgets::{Camera, ProviderImage, UrlRow},
+    models::{otp, Account, OTPMethod, OTPUri, Provider, ProvidersModel},
+    widgets::{Camera, ErrorRevealer, ProviderImage, UrlRow},
 };
-use anyhow::Result;
+use anyhow::{Context, Result};
+use gettextrs::gettext;
 use glib::{clone, signal::Inhibit};
 use gtk::{gio, glib, prelude::*, subclass::prelude::*, CompositeTemplate};
 use gtk_macros::{action, get_action};
@@ -52,6 +53,8 @@ mod imp {
         pub period_row: TemplateChild<adw::ActionRow>,
         #[template_child]
         pub provider_completion: TemplateChild<gtk::EntryCompletion>,
+        #[template_child]
+        pub error_revealer: TemplateChild<ErrorRevealer>,
     }
 
     impl ObjectSubclass for AccountAddDialog {
@@ -87,6 +90,7 @@ mod imp {
                 period_row: TemplateChild::default(),
                 deck: TemplateChild::default(),
                 camera: TemplateChild::default(),
+                error_revealer: TemplateChild::default(),
             }
         }
 
@@ -192,14 +196,23 @@ impl AccountAddDialog {
         let self_ = imp::AccountAddDialog::from_instance(self);
 
         if let Some(ref provider) = *self_.selected_provider.borrow() {
-            let username = self_.username_entry.get_text().unwrap();
-            let token = self_.token_entry.get_text().unwrap();
+            let username = self_
+                .username_entry
+                .get_text()
+                .context("Could not get text")?;
+            let token = self_.token_entry.get_text().context("Could not get text")?;
+            if !otp::is_valid(&token) {
+                self_.error_revealer.popup(&gettext("Invalid Token"));
+                anyhow::bail!("Token {} is not a valid Base32 secret", &token);
+            }
 
             let account = Account::create(&username, &token, provider)?;
 
             self_.model.get().unwrap().add_account(&account, &provider);
             self.emit("added", &[]).unwrap();
-            // TODO: display an error message saying there was an error form keyring
+        // TODO: display an error message saying there was an error form keyring
+        } else {
+            anyhow::bail!("Could not find provider");
         }
         Ok(())
     }