createSign not working consistently for non-RSA keys

[Fabian-Lobnig]

Hi,

I tested createSign with secp256k1 and secp256r1 key input and it randomly produces incorrect signatures but sometimes correct ones - I cross tested this with NodeJS which gives me this error whenever there is an incorrect signature:

error: Signature without r or s
      at assert (node:crypto:2371:39)
      at new Signature (node:crypto:7569:45)
      at node:crypto:7699:75

(As temporary workaround I used @noble-curves)