y not support them at all if either <i>kinv</i> or <i>r</i> is not NULL.</p>

<p>ECDSA_sign_setup() may be used to precompute parts of the signing operation. <i>eckey</i> is the private EC key and <i>ctx</i> is a pointer to <b>BN_CTX</b> structure (or NULL). The precomputed values or returned in <i>kinv</i> and <i>rp</i> and can be used in a later call to ECDSA_sign_ex() or ECDSA_do_sign_ex().</p>

<p>ECDSA_sign_ex() computes a digital signature of the <i>dgstlen</i> bytes hash value <i>dgst</i> using the p