Password validations: Add two new validators

Add two new custom password validators. One ensures
passwords have a minimum number of uppercase letters and the
other ensures passwords have a minimum amount of numbers.

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

mayan/apps/authentication/validators.py

@@ -0,0 +1,56 @@
+from __future__ import unicode_literals
+
+from django.core.exceptions import ValidationError
+from django.utils.translation import gettext as _
+
+
+class MinimumCapitalLettersContentValidator(object):
+    """
+    Validate whether the password contains a minimum number of uppercase
+    letters.
+    """
+    def __init__(self, minimum_capital_letters=1):
+        self.minimum_capital_letters = minimum_capital_letters
+
+    def validate(self, password, user=None):
+        if sum([1 for letter in password if letter.isupper()]) < self.minimum_capital_letters:  # NOQA
+            raise ValidationError(
+                _(
+                    'This password must contain at least '
+                    '%(minimum_capital_letters)d capital letters.'
+                ), code='password_not_enough_capital_letters',
+                params={
+                    'minimum_capital_letters': self.minimum_capital_letters
+                },
+            )
+
+    def get_help_text(self):
+        return _(
+            'Your password must contain at least %(minimum_capital_letters)d '
+            'capital letters.'
+            % {'minimum_capital_letters': self.minimum_capital_letters}
+        )
+
+
+class MinimumNumberContentValidator(object):
+    """
+    Validate whether the password contains a minimum number digits.
+    """
+    def __init__(self, minimum_numbers=1):
+        self.minimum_numbers = minimum_numbers
+
+    def validate(self, password, user=None):
+        if sum([1 for letter in password if letter.isdigit()]) < self.minimum_numbers:  # NOQA
+            raise ValidationError(
+                _(
+                    'This password must contain at least %(minimum_numbers)d '
+                    'numbers.'
+                ), code='password_not_enough_numbers',
+                params={'minimum_numbers': self.minimum_numbers},
+            )
+
+    def get_help_text(self):
+        return _(
+            'Your password must contain at least %(minimum_numbers)d numbers.'
+            % {'minimum_numbers': self.minimum_numbers}
+        )