[TESTNET] Pending transaction is rejected: Non-canonical signature: S value is unnecessarily high about bitcoinspv

[keeshux]

Farid, unfortunately I haven't been able to keep this library up-to-date through the years. Bitcoin changed quite a lot so I can't guarantee that the code is still complying. I can look into this but certainly not soon.

[pmattos]

Hey @keeshux, looks like I’m facing the exact same issue here :( I did some digging and this really looks related to this specific signature bounding issue.

I understand you are not actively maintaining this library anymore, but could you please point me out where you do such computations in your codebase so I can try fixing this myself instead?

Thanks!

[keeshux]

The relevant code for signatures is signatureForHash256 in Core/WSKey.m. It's been a while but, given that verbatim comment, the enforcement of "low S" in signature must have been taken from somewhere in Bitcoin Core:

https://bitcointalk.org/index.php?topic=285142.40

I suggest unit testing (R, S) in signatures, they're just big numbers (BIGNUM). Poking in the dark against the network could be very time-consuming.