client_cert_cb
int (*client_cert_cb)(SSL *ssl, X509 **x509,
int (*client_cert_cb)(SSL *ssl, X509 **x509, EVP_PKEY **pkey);
ctx->client_cert_cb = cb;
return ctx->client_cert_cb;
if (sctx->client_cert_cb)
i = sctx->client_cert_cb(SSL_CONNECTION_GET_USER_SSL(s), px509, ppkey);
SSL_CTX_set_client_cert_cb(cctx, client_cert_cb);
SSL_CTX_set_client_cert_cb(cctx, client_cert_cb);