Validate realname, username, and passwords on identity page

- Apply limits to realname (1..160)
- Apply limits to username (1..32)
- Restrict chars allowed for realname via RealnameEditor widget
- Ensure all fields have input

Signed-off-by: Ryan Harper <ryan.harper@canonical.com>

subiquity/ui/interactive.py

@@ -60,6 +60,20 @@ class PasswordEditor(StringEditor):
         super().__init__(caption, mask=mask)
 
 
+class RealnameEditor(StringEditor):
+    """ Username input prompt with input rules
+    """
+
+    def keypress(self, size, key):
+        ''' restrict what chars we allow for username '''
+
+        realname = r'[a-zA-Z0-9_\- ]'
+        if re.match(realname, key) is None:
+            return False
+
+        return super().keypress(size, key)
+
+
 class UsernameEditor(StringEditor):
     """ Username input prompt with input rules
     """

subiquity/ui/views/identity.py

@@ -22,20 +22,23 @@ import logging
 from urwid import (Pile, Columns, Text, ListBox)
 from subiquity.ui.buttons import done_btn, cancel_btn
 from subiquity.ui.interactive import (PasswordEditor,
-                                      StringEditor,
+                                      RealnameEditor,
                                       UsernameEditor)
 from subiquity.ui.utils import Padding, Color
 from subiquity.view import ViewPolicy
 
 log = logging.getLogger("subiquity.views.identity")
 
+USERNAME_MAXLEN = 32
+REALNAME_MAXLEN = 160
+
 
 class IdentityView(ViewPolicy):
     def __init__(self, model, signal):
         self.model = model
         self.signal = signal
         self.items = []
-        self.realname = StringEditor(caption="")
+        self.realname = RealnameEditor(caption="")
         self.username = UsernameEditor(caption="")
         self.password = PasswordEditor(caption="")
         self.error = Text("", align="center")
@@ -102,14 +105,37 @@ class IdentityView(ViewPolicy):
         return Pile(sl)
 
     def done(self, result):
+        if len(self.password.value) < 1:
+            self.error.set_text("Password must be set")
+            self.password.value = ""
+            self.confirm_password.value = ""
+            return
+
         if self.password.value != self.confirm_password.value:
             self.error.set_text("Passwords do not match.")
             self.password.value = ""
             self.confirm_password.value = ""
             return
 
-        if len(self.username.value) > 32:
-            self.error.set_text("Username too long, must be < 32")
+        if len(self.realname.value) < 1:
+            self.error.set_text("Realname missing.")
+            self.realname.value = ""
+            return
+
+        if len(self.realname.value) > REALNAME_MAXLEN:
+            self.error.set_text("Realname too long, must be < " +
+                                str(REALNAME_MAXLEN))
+            self.realname.value = ""
+            return
+
+        if len(self.username.value) < 1:
+            self.error.set_text("Username missing.")
+            self.username.value = ""
+            return
+
+        if len(self.username.value) > USERNAME_MAXLEN:
+            self.error.set_text("Username too long, must be < " +
+                                str(USERNAME_MAXLEN))
             self.username.value = ""
             return