From fa6304a5225787054067bb56089632146d288b20 Mon Sep 17 00:00:00 2001 From: Idan Moral Date: Tue, 24 Aug 2021 02:44:28 +0300 Subject: bpo-44690: Adopt binacii.a2b_base64's strict mode in base64.b64decode (GH-27272) * Use binascii.a2b_base64 to validate b64decode input. This change leads to exception messages changes (mostly). * Added more information to docstring of b64decode * Added a reference to binascii.a2b_base64 in the docs --- Doc/library/base64.rst | 2 ++ Lib/base64.py | 7 ++++--- Misc/NEWS.d/next/Library/2021-07-20-22-03-24.bpo-44690.tV7Zjg.rst | 1 + 3 files changed, 7 insertions(+), 3 deletions(-) create mode 100644 Misc/NEWS.d/next/Library/2021-07-20-22-03-24.bpo-44690.tV7Zjg.rst diff --git a/Doc/library/base64.rst b/Doc/library/base64.rst index f91547b..29e52ad 100644 --- a/Doc/library/base64.rst +++ b/Doc/library/base64.rst @@ -78,6 +78,8 @@ The modern interface provides: these non-alphabet characters in the input result in a :exc:`binascii.Error`. + For more information about the strict base64 check, see :func:`binascii.a2b_base64` + .. function:: standard_b64encode(s) diff --git a/Lib/base64.py b/Lib/base64.py index e1256ad..ffe2ce7 100755 --- a/Lib/base64.py +++ b/Lib/base64.py @@ -76,15 +76,16 @@ def b64decode(s, altchars=None, validate=False): normal base-64 alphabet nor the alternative alphabet are discarded prior to the padding check. If validate is True, these non-alphabet characters in the input result in a binascii.Error. + For more information about the strict base64 check, see: + + https://docs.python.org/3.11/library/binascii.html#binascii.a2b_base64 """ s = _bytes_from_decode_data(s) if altchars is not None: altchars = _bytes_from_decode_data(altchars) assert len(altchars) == 2, repr(altchars) s = s.translate(bytes.maketrans(altchars, b'+/')) - if validate and not re.fullmatch(b'[A-Za-z0-9+/]*={0,2}', s): - raise binascii.Error('Non-base64 digit found') - return binascii.a2b_base64(s) + return binascii.a2b_base64(s, strict_mode=validate) def standard_b64encode(s): diff --git a/Misc/NEWS.d/next/Library/2021-07-20-22-03-24.bpo-44690.tV7Zjg.rst b/Misc/NEWS.d/next/Library/2021-07-20-22-03-24.bpo-44690.tV7Zjg.rst new file mode 100644 index 0000000..1d11848 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2021-07-20-22-03-24.bpo-44690.tV7Zjg.rst @@ -0,0 +1 @@ +Adopt *binacii.a2b_base64*'s strict mode in *base64.b64decode*. \ No newline at end of file -- cgit v0.12