Index: django/contrib/localflavor/br/forms.py
===================================================================
--- django/contrib/localflavor/br/forms.py	(revision 4940)
+++ django/contrib/localflavor/br/forms.py	(working copy)
@@ -37,3 +37,36 @@
     def __init__(self, attrs=None):
         from br_states import STATE_CHOICES # relative import
         super(BRStateSelect, self).__init__(attrs, choices=STATE_CHOICES)
+
+def DV_maker(v):
+    if v >= 2:
+        return 11 - v
+    return 0
+
+class BRCNPJField(Field):
+    def clean(self, value):
+        """ value can be either a string in the format XX.XXX.XXX/XXXX-XX
+        or a group of 14 characters. """
+        if not value.isdigit():
+            value = re.sub("[-/\.]", "", value)
+        if len(value) != 14:
+            raise ValidationError(
+                gettext(u"This field requires at least 14 digits"))
+        orig_value = value[:]
+        orig_dv = value[-2:]
+
+        new_1dv = sum([i * int(value[idx])
+                         for idx, i in enumerate(range(5, 1, -1) +
+                                                 range(9, 1, -1))])
+        new_1dv = DV_maker(new_1dv % 11)
+        value = value[:-2] + str(new_1dv) + value[-1]
+        new_2dv = sum([i * int(value[idx])
+                         for idx, i in enumerate(range(6, 1, -1) +
+                                                 range(9, 1, -1))])
+        new_2dv = DV_maker(new_2dv % 11)
+        value = value[:-1] + str(new_2dv)
+        if (value[-2:] != orig_dv):
+            raise ValidationError(gettext(u"Invalid CNPJ number"))
+
+        return orig_value
+