fix: use io.ReadFull for salt generation #19
Merged
Conversation
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
Switch salt generation to io.ReadFull to reject short reads and prevent zero-padded, low-entropy salts when the RNG is swapped. Add a short-EOF RNG test to verify failure. Signed-off-by: Ville Vesilehto <[email protected]>
dhui
approved these changes
Sep 21, 2025
There was a problem hiding this comment.
Thanks for the find and fix @thevilledev !
EDIT: also thanks for adding a test to prevent a regression!
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Outdated suggestions cannot be applied.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.
Motivation
Salt generation used
io.Reader.Readand ignored short reads, allowing zero-padded, low-entropy salts when the RNG is swapped.Changes
Switch salt generation to use
io.ReadFull. Performance impact should be negligible.Prevents CWE-331 "Insufficient Entropy". Fails fast on RNG anomalies.
Testing
Add a short-EOF RNG test to verify failure. All tests pass.
Backwards Compatibility
No API changes. Credential creation will now error if the RNG short-reads instead of silently proceeding.