Lowercase SRV records in to_digestable(), fixes #496

1 files changed, 23 insertions, 0 deletions

diff --git a/tests/test_bugs.py b/tests/test_bugs.py
index 59e5f0e..e10f826 100644
--- a/tests/test_bugs.py
+++ b/tests/test_bugs.py
@@ -25,6 +25,8 @@ import dns.rdataclass
 import dns.rdatatype
 import dns.rdtypes.ANY.TXT
 import dns.ttl
+from dns import rdata, rdataclass, rdatatype
+
 
 class BugsTestCase(unittest.TestCase):
 
@@ -95,5 +97,26 @@ class BugsTestCase(unittest.TestCase):
         self.assertEqual(t1, t2)
         self.assertEqual(t1, t4)
 
+    def test_lowercase_canonicals(self):
+        for t, presentation_format in [
+            ('SRV', '100 1 5061 EXAMPLE.com.'),
+            # TODO also check NS, MD, MF, CNAME, SOA, MB, MG, MR, PTR,
+            #  HINFO, MINFO, MX, HINFO, RP, AFSDB, RT, SIG, PX, NXT,
+            #  NAPTR, KX, SRV, DNAME, A6, RRSIG, or NSEC
+        ]:
+            canonical_format = rdata.from_text(
+                    rdclass=rdataclass.IN,
+                    rdtype=rdatatype.from_text(t),
+                    tok=presentation_format,
+                    relativize=False
+                ).to_digestable()
+            self.assertIn(
+                b'example',
+                canonical_format,
+                f'Expected canonical format of {t} record type to have '
+                f'lowercase DNS names, but saw {canonical_format}.'
+            )
+
+
 if __name__ == '__main__':
     unittest.main()