gh-145264: Do not ignore excess Base64 data after the first padded quad#145267
Merged
serhiy-storchaka merged 4 commits intopython:mainfrom Mar 22, 2026
Merged
gh-145264: Do not ignore excess Base64 data after the first padded quad#145267serhiy-storchaka merged 4 commits intopython:mainfrom
serhiy-storchaka merged 4 commits intopython:mainfrom
Conversation
…ded quad Base64 decoder (see binascii.a2b_base64(), base64.b64decode(), etc) no longer ignores excess data after the first padded quad in non-strict (default) mode. Instead, in conformance with RFC 4648, it ignores the pad character, "=", if it is present before the end of the encoded data.
50967e0 to
0229b06
Compare
gpshead
reviewed
Feb 28, 2026
| @@ -0,0 +1,4 @@ | |||
| Base64 decoder (see :func:`binascii.a2b_base64`, :func:`base64.b64decode`, etc) no | |||
| longer ignores excess data after the first padded quad in non-strict | |||
| (default) mode. Instead, in conformance with :rfc:`4648`, it ignores | |||
Member
There was a problem hiding this comment.
I guess this is in accordance with the MAY in https://datatracker.ietf.org/doc/html/rfc4648#section-3.3 about ignoring PADs as non-alphabet data? it'd be good to cite the specific section.
Lib/test/test_binascii.py
Outdated
| # Test excess data exceptions | ||
| def assertExcessData(data, non_strict_expected, | ||
| ignore_padchar_expected=None): | ||
| def assertExcessData(data, non_strict_expected): |
Member
There was a problem hiding this comment.
rename this from non_strict_expected to just expected.
Member
Author
There was a problem hiding this comment.
In strict mode you get an error. You get that value only in non-strict mode, either when strict_mode=False, or when ignorechars contains "=".
But I agree that expected is shorter. The old name was even longer: non_strict_mode_expected_result.
Member
Author
|
@gpshead, could you please look again at that PR? |
Member
Author
|
Is it fine for you, @gpshead? |
gpshead
approved these changes
Mar 22, 2026
|
Thanks @serhiy-storchaka for the PR 🌮🎉.. I'm working now to backport this PR to: 3.13, 3.14. |
|
Sorry, @serhiy-storchaka, I could not cleanly backport this to |
|
Sorry, @serhiy-storchaka, I could not cleanly backport this to |
serhiy-storchaka
added a commit
to serhiy-storchaka/cpython
that referenced
this pull request
Mar 23, 2026
…rst padded quad (pythonGH-145267) Base64 decoder (see binascii.a2b_base64(), base64.b64decode(), etc) no longer ignores excess data after the first padded quad in non-strict (default) mode. Instead, in conformance with RFC 4648, it ignores the pad character, "=", if it is present before the end of the encoded data. (cherry picked from commit 4561f64) Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
|
GH-146326 is a backport of this pull request to the 3.14 branch. |
CuriousLearner
added a commit
to CuriousLearner/cpython
that referenced
this pull request
Mar 23, 2026
…8577 * 'main' of github.com:python/cpython: pythongh-146197: Run -m test.pythoninfo on the Emscripten CI (python#146332) pythongh-146325: Use `test.support.requires_fork` in test_fastpath_cache_cleared_in_forked_child (python#146330) pythongh-146197: Add Emscripten to CI (python#146198) pythongh-143387: Raise an exception instead of returning None when metadata file is missing. (python#146234) pythongh-108907: ctypes: Document _type_ codes (pythonGH-145837) pythongh-146175: Soft-deprecate outdated macros; convert internal usage (pythonGH-146178) pythongh-146056: Rework ref counting in treebuilder_handle_end() (python#146167) Add a warning about untrusted input to `configparser` docs (python#146276) pythongh-145264: Do not ignore excess Base64 data after the first padded quad (pythonGH-145267) pythongh-146308: Fix error handling issues in _remote_debugging module (python#146309) pythongh-146192: Add base32 support to binascii (pythonGH-146193) pythongh-135953: Properly obtain main thread identifier in Gecko Collector (python#146045) pythongh-143414: Implement unique reference tracking for JIT, optimize unpacking of such tuples (pythonGH-144300) pythongh-146261: Fix bug in `_Py_uop_sym_set_func_version` (pythonGH-146291) pythongh-145144: Add more tests for UserList, UserDict, etc (pythonGH-145145) pythongh-143959: Fix test_datetime if _datetime is unavailable (pythonGH-145248) pythongh-146245: Fix reference and buffer leaks via audit hook in socket module (pythonGH-146248) pythongh-140049: Colorize exception notes in `traceback.py` (python#140051) Update docs for pythongh-146056 (pythonGH-146213)
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Base64 decoder (see binascii.a2b_base64(), base64.b64decode(), etc) no longer ignores excess data after the first padded quad in non-strict (default) mode. Instead, in conformance with RFC 4648, it ignores the pad character, "=", if it is present before the end of the encoded data.