crypto: allow importing compact secp256k1 pubkey through recovery#27
Merged
MichaelMure merged 1 commit intomasterfrom Mar 24, 2026
Merged
crypto: allow importing compact secp256k1 pubkey through recovery#27MichaelMure merged 1 commit intomasterfrom
MichaelMure merged 1 commit intomasterfrom
Conversation
smoyer64
approved these changes
Mar 24, 2026
| if len(signature) != 65 { | ||
| return nil, fmt.Errorf("secp256k1: invalid compact signature length: expected 65 bytes, got %d", len(signature)) | ||
| } | ||
| pub, _, err := ecdsa.RecoverCompact(signature, hash) |
Collaborator
There was a problem hiding this comment.
Interesting - doing the same thing with the go-ethereum library requires adding 27 and maybe 4 but this is waaaay cleaner (ref: https://pkg.go.dev/github.com/decred/dcrd/dcrec/secp256k1/v4@v4.4.1/ecdsa#SignCompact)
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
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
Note
Medium Risk
Adds new public-key recovery API based on ECDSA compact signatures; main risk is misuse or accepting malformed inputs if callers pass non-hash data or wrong signature formats.
Overview
Adds
PublicKeyFromCompactRecovery, allowing secp256k1 public keys to be derived from a 65-byte compact signature (recovery flag + R/S) and the message hash viaecdsa.RecoverCompact, with explicit length validation and wrapped errors.Extends the secp256k1 test suite with a new unit test that signs a SHA-256 hash using
ecdsa.SignCompactand verifies the recovered key matches the original.Written by Cursor Bugbot for commit 46d6ce9. This will update automatically on new commits. Configure here.