Hardening: Enforce length of keys for HMAC operations #369
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
Adds a validation check to ensure that keys used for HMAC-based JWS algorithms (HS256, HS384, HS512) are at least as large as the hash algorithm's output size. This change aligns the library with RFC 7518, Section 3.2, which mandates this minimum key size. An `InvalidJWEKeyLength` exception is now raised if an undersized key is used. Tests were updated to generate and use keys of the appropriate size to pass the new validation. Signed-off-by: Simo Sorce <simo@redhat.com>
Adds a new global flag, `jwa.default_enforce_hmac_key_length`, to control whether RFC 7518 key length requirements are enforced for HMAC-based JWS algorithms. By default, the check remains enabled to ensure secure key sizes are used. Setting this flag to `False` allows the use of undersized keys, providing an escape hatch for interoperability with non-compliant systems. Co-authored-by: Gemini <gemini@google.com> Signed-off-by: Simo Sorce <simo@redhat.com>
This commit improves the project documentation in several ways: - The internal `jwcrypto.jwa` module, which implements the JSON Web Algorithms, is now documented. - Docstrings are added to module-level settings in `jwa.py` to clarify their purpose and security considerations. - The main table of contents is reorganized to separate public APIs from internal modules. Co-authored-by: Gemini <gemini@google.com> Signed-off-by: Simo Sorce <simo@redhat.com>
Signed-off-by: Simo Sorce <simo@redhat.com>
rjeffman
reviewed
Oct 22, 2025
rjeffman
reviewed
Oct 22, 2025
Member
Author
|
@rjeffman thanks a lot for the review! |
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.
Enforce minimum HMAC key size per RFC 7518
Adds a validation check to ensure that keys used for HMAC-based JWS
algorithms (HS256, HS384, HS512) are at least as large as the hash
algorithm's output size.
This change aligns the library with RFC 7518, Section 3.2, which
mandates this minimum key size.
Fixes #368