1 if enough space was available to serialize, 0 otherwise Args: ctx: a secp256k1 context object Out: output: a pointer to an array to store the DER serialization In/Out: outputlen: a pointer to a length integer. Initially, this integer should be set to the length of output. After the call it will be set to the length of the serialization (even if 0 was returned). In: sig: a pointer to an initialized signature object
Serialize an ECDSA signature in DER format.