New error message for signature algorithms accepting an unique nb of chars.

src/App/DisplayErrors.purs

@@ -1,7 +1,7 @@
 -- | This module provides functions to display errors in a fancy way.
 module App.DisplayErrors where
 
-import Prelude (show, ($), (<>))
+import Prelude (show, ($), (<>), (==))
 
 -- import Data.Foldable as Foldable
 import Data.Maybe (Maybe(..), maybe)
@@ -60,7 +60,9 @@ error_to_paragraph v = Bulma.error_message (Bulma.p $ show_error_title v)
 
 show_error_key_sizes :: forall w i. Int -> Int -> HH.HTML w i
 show_error_key_sizes min max
-  = Bulma.p $ "Chosen signature algorithm only accepts public key input between "
+  = if min == max
+    then Bulma.p $ "Chosen signature algorithm only accepts public key input of " <> show min <> " characters."
+    else Bulma.p $ "Chosen signature algorithm only accepts public key input between "
               <> show min <> " and " <> show max <> " characters."
 
 -- | `show_error_title` provide a simple title string to display to the user in case of an error with an entry.