Skip to content

fix: Switch anonymous user ID hash from md5 to shake #26198

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
jinder1s merged 5 commits into from
Feb 10, 2021
Merged

fix: Switch anonymous user ID hash from md5 to shake #26198

Show file tree
Hide file tree
Changes from 3 commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
63240b1
refactor: switching hashing algorithm for md5 to shake
Jan 27, 2021
d5d30ec
fix: quality
Jan 27, 2021
874acdd
fix: tests hardcoded for shake algorithm
Jan 27, 2021
e80c93d
Update common/djangoapps/student/models.py
jinder1s Jan 29, 2021
19d1d40
Merge branch 'master' into msingh/refactor/hashing/md5/shake
jinder1s Feb 9, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
10 changes: 8 additions & 2 deletions common/djangoapps/student/models.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -200,12 +200,18 @@ def anonymous_id_for_user(user, course_id, save=True):
monitoring.increment('temp_anon_uid_v2.fetched_existing')
else:
# include the secret key as a salt, and to make the ids unique across different LMS installs.
hasher = hashlib.md5()
hasher = hashlib.shake_128()

@timmc-edx timmc-edx Jan 27, 2021

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

No test changes?

Incidentally, I'd call this a fix in the nomenclature of Conventional Commits.

@jinder1s jinder1s Jan 27, 2021

Copy link
Copy Markdown
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Oh no, yep, there will be.

@jinder1s jinder1s Jan 27, 2021

Copy link
Copy Markdown
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

hmmm, I can kinda see, but still think it doesn't really work. We are not fixing a bug, we are just moving to a better algorithm.

@timmc-edx timmc-edx Jan 27, 2021

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Honestly, I'm not real thrilled by the options suggested in that spec. :-) This isn't a feature, and it's not exactly a bug fix, it's... an "improvement".

# This is one of several uses of SECRET_KEY.
#
# Impact of exposure: If a person has the SECRET_KEY and a user's `id`
# they can correlate the users anonymous user IDs across any courses they have participated in.
#
# Rotation process: Can be rotated at will.
Comment thread
jinder1s marked this conversation as resolved.
Resolved
hasher.update(settings.SECRET_KEY.encode('utf8'))
hasher.update(text_type(user.id).encode('utf8'))
if course_id:
hasher.update(text_type(course_id).encode('utf-8'))
anonymous_user_id = hasher.hexdigest()
anonymous_user_id = hasher.hexdigest(16) # pylint: disable=too-many-function-args

if save is True:
try:
Expand Down
6 changes: 3 additions & 3 deletions lms/djangoapps/courseware/tests/test_module_render.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1991,7 +1991,7 @@ def test_per_student_anonymized_id(self, descriptor_class):
self.assertEqual(
# This value is set by observation, so that later changes to the student
# id computation don't break old data
'5afe5d9bb03796557ee2614f5c9611fb',
'de619ab51c7f4e9c7216b4644c24f3b5',
Comment thread
jinder1s marked this conversation as resolved.
Resolved
self._get_anonymous_id(CourseKey.from_string(course_id), descriptor_class)
)

Expand All @@ -2000,14 +2000,14 @@ def test_per_course_anonymized_id(self, descriptor_class):
self.assertEqual(
# This value is set by observation, so that later changes to the student
# id computation don't break old data
'e3b0b940318df9c14be59acb08e78af5',
'0c706d119cad686d28067412b9178454',
self._get_anonymous_id(CourseKey.from_string('MITx/6.00x/2012_Fall'), descriptor_class)
)

self.assertEqual(
# This value is set by observation, so that later changes to the student
# id computation don't break old data
'f82b5416c9f54b5ce33989511bb5ef2e',
'e9969c28c12c8efa6e987d6dbeedeb0b',
self._get_anonymous_id(CourseKey.from_string('MITx/6.00x/2013_Spring'), descriptor_class)
)

Expand Down