SSL_CTX_use_psk_identity_hint
if (!SSL_CTX_use_psk_identity_hint(ctx, psk_identity_hint)) {
__owur int SSL_CTX_use_psk_identity_hint(SSL_CTX *ctx, const char *identity_hint);
if (!SSL_CTX_use_psk_identity_hint(s_ctx, "ctx server identity_hint") || !SSL_CTX_use_psk_identity_hint(s_ctx2, "ctx server identity_hint")) {