tests: fix flaky ja4 test #5169
Merged
Conversation
This file contains 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
maddeleine
reviewed
Mar 7, 2025
| RESULT_GUARD_POSIX(s2n_stuffer_skip_write(&bytes, ciphers_size)); | ||
| for (size_t i = 0; i < cipher_count; i++) { | ||
| RESULT_GUARD_POSIX(s2n_stuffer_write_uint16(&bytes, 0)); | ||
| } |
There was a problem hiding this comment.
Yeah I agree this is more correct. If you're worried about the test still being flaky you could always add a debugging print statement if the test fails.
There was a problem hiding this comment.
I'm leaning towards only doing that if this doesn't work. I'm pretty confident this will work.
CarolYeh910
approved these changes
Mar 7, 2025
maddeleine
approved these changes
Mar 7, 2025
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
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Outdated suggestions cannot be applied.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.
Release Summary:
Description of changes:
The JA4 test has been failing on AL2 randomly. See this test run. It fails with:
I think the problem is this chunk of code from the test setup:
https://github.com/lrstewart/s2n/blob/2c0f038397a8660732a5c15eebca085373d7569b/tests/unit/s2n_fingerprint_ja4_test.c#L148-L150
Basically, instead of writing individual cipher suite ianas, since we didn't care what the ianas were we just skipped over the right size chunk of data. But stuffers don't initialize their memory, so the data that ends up representing cipher ianas is whatever malloc returns. I suspect in most environments that memory is 0s, but AL2 is giving more random values, some of which happen to be grease values. JA4 doesn't count grease values when counting cipher suites, so the test fails.
Testing:
Hard to prove, since it's flaky. So far I've failed to repro the failures by:
But this change doesn't break anything, is more correct, and /may/ fix the flakiness.
By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.