EVP_SignFinal
EVP_SignFinal(ctx, *sig, sig_len, pkey);
|| !EVP_SignFinal(ctx, (unsigned char *)buf_out,
if (EVP_SignFinal(ctx, m, &m_len, pkey) <= 0)
__owur int EVP_SignFinal(EVP_MD_CTX *ctx, unsigned char *md, unsigned int *s,