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python-dns/SOURCES/fix_unicode_label_escaping....

162 lines
5.1 KiB

From c28f0584ba37cd6b0e9919dcbec652a34a420843 Mon Sep 17 00:00:00 2001
From: Lumir Balhar <lbalhar@redhat.com>
Date: Wed, 28 Aug 2019 14:10:36 +0200
Subject: [PATCH] Backported original patch from:
https://github.com/rthalley/dnspython/commit/c76aa6ac9969447220c8e807aa1e5640a6c12924
Unicode label escapify was not escapifying special characters. [Issue #339]
---
dns/name.py | 57 +++++++++++++++++++++++-----------------------
tests/test_name.py | 5 ++++
2 files changed, 34 insertions(+), 28 deletions(-)
diff --git a/dns/name.py b/dns/name.py
index 97e216c..4a064d6 100644
--- a/dns/name.py
+++ b/dns/name.py
@@ -116,20 +116,28 @@ class IDNACodec(object):
def __init__(self):
pass
+ def is_idna(self, label):
+ return label.lower().startswith(b'xn--')
+
+ def is_all_ascii(self, label):
+ for c in label:
+ if ord(c) > 0x7f:
+ return False
+ return True
+
def encode(self, label):
raise NotImplementedError
def decode(self, label):
- # We do not apply any IDNA policy on decode; we just
- downcased = label.lower()
- if downcased.startswith(b'xn--'):
+ # We do not apply any IDNA policy on decode.
+ if self.is_idna(label):
try:
- label = downcased[4:].decode('punycode')
+ label = label[4:].decode('punycode')
except Exception as e:
raise IDNAException(idna_exception=e)
else:
label = maybe_decode(label)
- return _escapify(label, True)
+ return _escapify(label)
class IDNA2003Codec(IDNACodec):
@@ -159,7 +167,7 @@ class IDNA2003Codec(IDNACodec):
if label == b'':
return u''
try:
- return _escapify(encodings.idna.ToUnicode(label), True)
+ return _escapify(encodings.idna.ToUnicode(label))
except Exception as e:
raise IDNAException(idna_exception=e)
@@ -197,12 +205,6 @@ class IDNA2008Codec(IDNACodec):
self.allow_pure_ascii = allow_pure_ascii
self.strict_decode = strict_decode
- def is_all_ascii(self, label):
- for c in label:
- if ord(c) > 0x7f:
- return False
- return True
-
def encode(self, label):
if label == '':
return b''
@@ -227,11 +229,12 @@ class IDNA2008Codec(IDNACodec):
try:
if self.uts_46:
label = idna.uts46_remap(label, False, False)
- return _escapify(idna.ulabel(label), True)
+ return _escapify(idna.ulabel(label))
except idna.IDNAError as e:
raise IDNAException(idna_exception=e)
_escaped = bytearray(b'"().;\\@$')
+_escaped_text = '"().;\\@$'
IDNA_2003_Practical = IDNA2003Codec(False)
IDNA_2003_Strict = IDNA2003Codec(True)
@@ -242,13 +245,13 @@ IDNA_2008_Strict = IDNA2008Codec(False, False, False, True)
IDNA_2008_Transitional = IDNA2008Codec(True, True, False, False)
IDNA_2008 = IDNA_2008_Practical
-def _escapify(label, unicode_mode=False):
+def _escapify(label):
"""Escape the characters in label which need it.
- @param unicode_mode: escapify only special and whitespace (<= 0x20)
- characters
@returns: the escaped string
@rtype: string"""
- if not unicode_mode:
+ if isinstance(label, bytes):
+ # Ordinary DNS label mode. Escape special characters and values
+ # < 0x20 or > 0x7f.
text = ''
if isinstance(label, text_type):
label = label.encode()
@@ -259,19 +262,17 @@ def _escapify(label, unicode_mode=False):
text += chr(c)
else:
text += '\\%03d' % c
- return text.encode()
+ return text
+ # Unicode label mode. Escape only special characters and values < 0x20
text = u''
- if isinstance(label, binary_type):
- label = label.decode()
for c in label:
- if c > u'\x20' and c < u'\x7f':
- text += c
+ if c in _escaped_text:
+ text += '\\' + c
+ elif c <= '\x20':
+ text += '\\%03d' % ord(c)
else:
- if c >= u'\x7f':
- text += c
- else:
- text += u'\\%03d' % ord(c)
+ text += c
return text
def _validate_labels(labels):
@@ -519,8 +520,8 @@ class Name(object):
l = self.labels[:-1]
else:
l = self.labels
- s = b'.'.join(map(_escapify, l))
- return maybe_decode(s)
+ s = '.'.join(map(_escapify, l))
+ return s
def to_unicode(self, omit_final_dot=False, idna_codec=None):
"""Convert name to Unicode text format.
diff --git a/tests/test_name.py b/tests/test_name.py
index f2a8773..fa1d3eb 100644
--- a/tests/test_name.py
+++ b/tests/test_name.py
@@ -255,6 +255,11 @@ class NameTestCase(unittest.TestCase):
t = dns.name.root.to_unicode()
self.assertEqual(t, '.')
+ def testToText12(self):
+ n = dns.name.from_text(r'a\.b.c')
+ t = n.to_unicode()
+ self.assertEqual(t, r'a\.b.c.')
+
def testSlice1(self):
n = dns.name.from_text(r'a.b.c.', origin=None)
s = n[:]
--
2.21.0