ee <a href="../man3/SRP_VBASE_init.html">SRP_VBASE_init(3)</a> to parse the verifier file created by <a href="../man1/openssl-srp.html">openssl-srp(1)</a> or <a href="../man3/SRP_create_verifier.html">SRP_create_verifier(3)</a> to generate it. The callback should return <b>SSL_ERROR_NONE</b> to proceed with the server key exchange, <b>SSL3_AL_FATAL</b> for a fatal error or any value &lt; 0 for a retryable error. In the event of a <b>SSL3_AL_FATAL</b> the alert flag given by <b>*al</b> will be sent back. By 