OSSL_PARAM_BUF_PUBLIC
if (!ossl_param_buf_alloc(&buf[OSSL_PARAM_BUF_PUBLIC], param_blocks, 0))
OPENSSL_free(buf[OSSL_PARAM_BUF_PUBLIC].alloc);
dst = (OSSL_PARAM *)buf[OSSL_PARAM_BUF_PUBLIC].alloc;