fix: signature verification due to leading zeros #326
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
According to FIPS 186-5, section 6.4.2 ECDSA Signature
Verification Algorithm, the hash of the message must be adjusted
based on the order n of the base point of the elliptic curve:
If log2(n) ≥ hashlen, set E = H. Otherwise, set E equal to
the leftmost log2(n) bits of H.
Unfortunately because elliptic converts messages to BN instances the
reported `byteLength()` for the message can be incorrect if the message
has 8 or more leading zero bits.
Here we fix it by:
1. Counting leading zeroes in hex strings provided as messages
2. Counting all array entries in Array-like (e.g. Buffer)
messages
3. Providing an `msgBitLength` option to both `.sign`/`.verify` to let
user override the behavior
Original PR: #322
Credit: @Markus-MS
paulmillr
approved these changes
Oct 25, 2024
|
Who would use |
|
@paulmillr thanks for the review! I just wanted to provide an escape hatch for people whom this patch broke 😭 |
|
Published in 6.6.0. Thank you! |
This was referenced Oct 28, 2024
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Outdated suggestions cannot be applied.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.
According to FIPS 186-5, section 6.4.2 ECDSA Signature Verification Algorithm, the hash of the message must be adjusted based on the order n of the base point of the elliptic curve:
Unfortunately because elliptic converts messages to BN instances the reported
byteLength()for the message can be incorrect if the message has 8 or more leading zero bits.Here we fix it by:
msgBitLengthoption to both.sign/.verifyto let user override the behaviorOriginal PR: #322
Credit: @Markus-MS