modify random password generator function make_password() to always include at least one of the possible string groups (ascii_letters, digits, special characters etc.)

modoboa/admin/lib.py

@@ -294,13 +294,27 @@ def make_password():
     """Create a random password."""
     length = int(param_tools.get_global_parameter("random_password_length", app="core"))
     allow_special_characters = bool(param_tools.get_global_parameter("allow_special_characters", app="core"))
-    possible_chars = string.ascii_letters + string.digits
+    possible_chars_types = [string.ascii_letters, string.digits]
+    all_possible_chars = ''
+    certain_chars = ''
     for i in range(10): # limit tries
         if allow_special_characters: # add special characters in random passwd
-            possible_chars += string.punctuation
+            possible_chars_types.append(string.punctuation)
+        # make it so there is always one character of each type in password
+        # and then will randomize their placement
+        for possible_chars in possible_chars_types:
+            all_possible_chars += possible_chars
+            certain_chars += random.SystemRandom().choice(possible_chars)
+        
         password = "".join(
-            random.SystemRandom().choice(possible_chars) for _ in range(length)
-        )
+            random.SystemRandom().choice(all_possible_chars) \
+                for _ in range(length - len(possible_chars_types))
+        ) + certain_chars
+        
+        li_password = list(password)
+        random.shuffle(li_password)
+        password = "".join(li_password)
+        
         try:
             password_validation.validate_password(password)
         except ValidationError: