Issue #24848: Fixed bugs in UTF-7 decoding of misformed data:

1. Non-ASCII bytes were accepted after shift sequence.
2. A low surrogate could be emitted in case of error in high surrogate.
This commit is contained in:
Serhiy Storchaka 2015-10-02 13:14:53 +03:00
parent a87633e596
commit e12f632186
4 changed files with 71 additions and 7 deletions

View File

@ -642,6 +642,32 @@ class UTF8Test(ReadTest):
class UTF7Test(ReadTest):
encoding = "utf-7"
def test_ascii(self):
# Set D (directly encoded characters)
set_d = ('ABCDEFGHIJKLMNOPQRSTUVWXYZ'
'abcdefghijklmnopqrstuvwxyz'
'0123456789'
'\'(),-./:?')
self.assertEqual(set_d.encode(self.encoding), set_d)
self.assertEqual(set_d.decode(self.encoding), set_d)
# Set O (optional direct characters)
set_o = ' !"#$%&*;<=>@[]^_`{|}'
self.assertEqual(set_o.encode(self.encoding), set_o)
self.assertEqual(set_o.decode(self.encoding), set_o)
# +
self.assertEqual(u'a+b'.encode(self.encoding), 'a+-b')
self.assertEqual('a+-b'.decode(self.encoding), u'a+b')
# White spaces
ws = ' \t\n\r'
self.assertEqual(ws.encode(self.encoding), ws)
self.assertEqual(ws.decode(self.encoding), ws)
# Other ASCII characters
other_ascii = ''.join(sorted(set(chr(i) for i in range(0x80)) -
set(set_d + set_o + '+' + ws)))
self.assertEqual(other_ascii.encode(self.encoding),
'+AAAAAQACAAMABAAFAAYABwAIAAsADAAOAA8AEAARABIAEwAU'
'ABUAFgAXABgAGQAaABsAHAAdAB4AHwBcAH4Afw-')
def test_partial(self):
self.check_partial(
u"a+-b",
@ -656,7 +682,9 @@ class UTF7Test(ReadTest):
def test_errors(self):
tests = [
('\xffb', u'\ufffdb'),
('a\xffb', u'a\ufffdb'),
('a\xff\xffb', u'a\ufffd\ufffdb'),
('a+IK', u'a\ufffd'),
('a+IK-b', u'a\ufffdb'),
('a+IK,b', u'a\ufffdb'),
@ -672,6 +700,8 @@ class UTF7Test(ReadTest):
('a+//,+IKw-b', u'a\ufffd\u20acb'),
('a+///,+IKw-b', u'a\uffff\ufffd\u20acb'),
('a+////,+IKw-b', u'a\uffff\ufffd\u20acb'),
('a+IKw-b\xff', u'a\u20acb\ufffd'),
('a+IKw\xffb', u'a\u20ac\ufffdb'),
]
for raw, expected in tests:
self.assertRaises(UnicodeDecodeError, codecs.utf_7_decode,
@ -682,6 +712,35 @@ class UTF7Test(ReadTest):
self.assertEqual(u'\U000104A0'.encode(self.encoding), '+2AHcoA-')
self.assertEqual(u'\ud801\udca0'.encode(self.encoding), '+2AHcoA-')
self.assertEqual('+2AHcoA-'.decode(self.encoding), u'\U000104A0')
self.assertEqual('+2AHcoA'.decode(self.encoding), u'\U000104A0')
self.assertEqual(u'\u20ac\U000104A0'.encode(self.encoding), '+IKzYAdyg-')
self.assertEqual('+IKzYAdyg-'.decode(self.encoding), u'\u20ac\U000104A0')
self.assertEqual('+IKzYAdyg'.decode(self.encoding), u'\u20ac\U000104A0')
self.assertEqual(u'\u20ac\u20ac\U000104A0'.encode(self.encoding),
'+IKwgrNgB3KA-')
self.assertEqual('+IKwgrNgB3KA-'.decode(self.encoding),
u'\u20ac\u20ac\U000104A0')
self.assertEqual('+IKwgrNgB3KA'.decode(self.encoding),
u'\u20ac\u20ac\U000104A0')
def test_lone_surrogates(self):
tests = [
('a+2AE-b', u'a\ud801b'),
('a+2AE\xffb', u'a\ufffdb'),
('a+2AE', u'a\ufffd'),
('a+2AEA-b', u'a\ufffdb'),
('a+2AH-b', u'a\ufffdb'),
('a+IKzYAQ-b', u'a\u20ac\ud801b'),
('a+IKzYAQ\xffb', u'a\u20ac\ufffdb'),
('a+IKzYAQA-b', u'a\u20ac\ufffdb'),
('a+IKzYAd-b', u'a\u20ac\ufffdb'),
('a+IKwgrNgB-b', u'a\u20ac\u20ac\ud801b'),
('a+IKwgrNgB\xffb', u'a\u20ac\u20ac\ufffdb'),
('a+IKwgrNgB', u'a\u20ac\u20ac\ufffd'),
('a+IKwgrNgBA-b', u'a\u20ac\u20ac\ufffdb'),
]
for raw, expected in tests:
self.assertEqual(raw.decode('utf-7', 'replace'), expected)
class UTF16ExTest(unittest.TestCase):

View File

@ -1036,6 +1036,7 @@ class UnicodeTest(
self.assertRaises(UnicodeError, unicode, 'Andr\202 x', 'ascii','strict')
self.assertEqual(unicode('Andr\202 x','ascii','ignore'), u"Andr x")
self.assertEqual(unicode('Andr\202 x','ascii','replace'), u'Andr\uFFFD x')
self.assertEqual(unicode('\202 x', 'ascii', 'replace'), u'\uFFFD x')
self.assertEqual(u'abcde'.decode('ascii', 'ignore'),
u'abcde'.decode('ascii', errors='ignore'))
self.assertEqual(u'abcde'.decode('ascii', 'replace'),

View File

@ -10,6 +10,8 @@ What's New in Python 2.7.11?
Core and Builtins
-----------------
- Issue #24848: Fixed a number of bugs in UTF-7 decoding of misformed data.
- Issue #25003: os.urandom() doesn't use getentropy() on Solaris because
getentropy() is blocking, whereas os.urandom() should not block. getentropy()
is supported since Solaris 11.3.

View File

@ -1716,29 +1716,29 @@ PyObject *PyUnicode_DecodeUTF7Stateful(const char *s,
}
else { /* now leaving a base-64 section */
inShift = 0;
s++;
if (surrogate) {
*p++ = surrogate;
surrogate = 0;
}
if (base64bits > 0) { /* left-over bits */
if (base64bits >= 6) {
/* We've seen at least one base-64 character */
s++;
errmsg = "partial character in shift sequence";
goto utf7Error;
}
else {
/* Some bits remain; they should be zero */
if (base64buffer != 0) {
s++;
errmsg = "non-zero padding bits in shift sequence";
goto utf7Error;
}
}
}
if (ch != '-') {
if (surrogate && DECODE_DIRECT(ch))
*p++ = surrogate;
surrogate = 0;
if (ch == '-') {
/* '-' is absorbed; other terminating
characters are preserved */
*p++ = ch;
s++;
}
}
}
@ -1751,6 +1751,7 @@ PyObject *PyUnicode_DecodeUTF7Stateful(const char *s,
}
else { /* begin base64-encoded section */
inShift = 1;
surrogate = 0;
shiftOutStart = p;
base64bits = 0;
base64buffer = 0;
@ -1782,6 +1783,7 @@ utf7Error:
if (inShift && !consumed) { /* in shift sequence, no more to follow */
/* if we're in an inconsistent state, that's an error */
inShift = 0;
if (surrogate ||
(base64bits >= 6) ||
(base64bits > 0 && base64buffer != 0)) {