From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.7 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9A451C43331 for ; Sat, 9 Nov 2019 13:29:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5644A21848 for ; Sat, 9 Nov 2019 13:29:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="PfnkjBA6" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726320AbfKIN3B (ORCPT ); Sat, 9 Nov 2019 08:29:01 -0500 Received: from mail-pf1-f180.google.com ([209.85.210.180]:34912 "EHLO mail-pf1-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726307AbfKIN3B (ORCPT ); Sat, 9 Nov 2019 08:29:01 -0500 Received: by mail-pf1-f180.google.com with SMTP id d13so7062847pfq.2 for ; Sat, 09 Nov 2019 05:29:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to; bh=V0dcfjSsClF9Vvn2QG0lFTvRyH4w1Rt9rORwYtF7hsg=; b=PfnkjBA6dB62KLBpuTBR/rBX5fTbuE0njk0prFq62ukCHULmsh02gpZVvwFa+bfq0h ok/v/PYheYnhih4wlkP/MY5YQFVmzj7g+SINZsiO/DAnlhcjonDcHHuGpeEWP1JJKrAe 2pssqN7XBsZQdblZ20cEZj7qztj82zrBjv7YjYtQ01b0+kM/7aYz52IaCfuoOc6kaT0g oZqkvMN756xHy39jQkCBqR7CQ+oS+QrZNXr78rZBIdCJ97LBJUR3mr4wbSDy7PVI+i+g 98Q5tQqIEvEKpOJUorwQpdh2T+IjGZYWk4b1kZccmNAtD7C/hndsV5q6i+/8p/oyVFoU MCzw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=V0dcfjSsClF9Vvn2QG0lFTvRyH4w1Rt9rORwYtF7hsg=; b=YkPOwqTZoJOLF56lRG9Kdqynd/wZ3dxxhCdv1xNoo3rnLkdy+xw5izcqw2T5odCbqU vOcxPJ/5Cw8plgfLU5VRt0PxLjpfcK/+d/FLk81nyqwZjpKPslnWOh8UNc1A3USzmTDr NU+OnC665QbLKeIr5MCAgTLJM7VG6rGljJfXcV0bRMl70JDke6rLaS7uZzyqQzG+Gd2k PoKWFuj4OsguUKB0mY3tkVarSaxbkCzlcLQL6aZevaBwi9buKmEb7VAlA9vHKGnk1oih 5+qS0sEOnMPyHV99pKgc4JH93ciwpBT/hqigfCKakkBMR3NmtepJuK71cAm82U681jhX RTgw== X-Gm-Message-State: APjAAAXR5tQkJkf6YDDBcnyjyNcPTXuAf4TytXq+Le/65S9BKYM6zxiC p7zMq5vAwhUn3ne3kWwF/A8A+DJ+4ipWq2VLpA55fg== X-Google-Smtp-Source: APXvYqw6pGPC3sFRpLalCPFQx6RZ1pKa1V01s5kiRF4Sq+Rqb6PtzjWia9Fo6pW6zEh7d6XhK5UqY+wUTlZFrYc6bE8= X-Received: by 2002:a63:6286:: with SMTP id w128mr5617853pgb.290.1573306139750; Sat, 09 Nov 2019 05:28:59 -0800 (PST) MIME-Version: 1.0 Received: by 2002:a17:90a:23ab:0:0:0:0 with HTTP; Sat, 9 Nov 2019 05:28:59 -0800 (PST) From: "Thomas P. K. Healy" Date: Sat, 9 Nov 2019 13:28:59 +0000 Message-ID: Subject: Re: Remove PRNG from Linux Kernel To: linux-crypto@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org I've done performance testing, and I can generate 50 kilobytes of random data in 6.9 seconds using the TMP2 hardware. This is adequate. The boot-up state of my embedded device is very predictable, and so I don't want any mathematical algorithms for psudeo-randomness present on my device. I am cutting them all out. I don't want to use the TPM2 to feed entropy into the Linux kernel's PRNG. Instead I wish to remove the PRNG from the kernel and replace it with a direct call to the TPM2 chip. Performance is not an issue here.