From patchwork Fri Dec 18 09:28:04 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthias Brugger X-Patchwork-Id: 1418139 X-Patchwork-Delegate: trini@ti.com Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.denx.de (client-ip=2a01:238:438b:c500:173d:9f52:ddab:ee01; helo=phobos.denx.de; envelope-from=u-boot-bounces@lists.denx.de; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=kernel.org Received: from phobos.denx.de (phobos.denx.de [IPv6:2a01:238:438b:c500:173d:9f52:ddab:ee01]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4Cy3TQ4bPMz9sW8 for ; Fri, 18 Dec 2020 20:28:58 +1100 (AEDT) Received: from h2850616.stratoserver.net (localhost [IPv6:::1]) by phobos.denx.de (Postfix) with ESMTP id 2D00882C8E; Fri, 18 Dec 2020 10:28:39 +0100 (CET) Authentication-Results: phobos.denx.de; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: phobos.denx.de; spf=pass smtp.mailfrom=u-boot-bounces@lists.denx.de Received: by phobos.denx.de (Postfix, from userid 109) id C13AE82C85; Fri, 18 Dec 2020 10:28:34 +0100 (CET) X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on phobos.denx.de X-Spam-Level: X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_HI, SPF_HELO_NONE autolearn=ham autolearn_force=no version=3.4.2 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by phobos.denx.de (Postfix) with ESMTPS id E027382C7A for ; Fri, 18 Dec 2020 10:28:31 +0100 (CET) Authentication-Results: phobos.denx.de; dmarc=pass (p=none dis=none) header.from=kernel.org Authentication-Results: phobos.denx.de; spf=pass smtp.mailfrom=matthias.bgg@kernel.org From: matthias.bgg@kernel.org Authentication-Results: mail.kernel.org; dkim=permerror (bad message/signature format) To: joe.hershberger@ni.com, sjg@chromium.org Cc: u-boot@lists.denx.de, duwe@suse.de, pbrobinson@gmail.com, Matthias Brugger Subject: [PATCH v3 2/2] net: Use NDRNG device in srand_mac() Date: Fri, 18 Dec 2020 10:28:04 +0100 Message-Id: <20201218092804.19753-3-matthias.bgg@kernel.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201218092804.19753-1-matthias.bgg@kernel.org> References: <20201218092804.19753-1-matthias.bgg@kernel.org> MIME-Version: 1.0 X-BeenThere: u-boot@lists.denx.de X-Mailman-Version: 2.1.34 Precedence: list List-Id: U-Boot discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: u-boot-bounces@lists.denx.de Sender: "U-Boot" X-Virus-Scanned: clamav-milter 0.102.3 at phobos.denx.de X-Virus-Status: Clean From: Matthias Brugger When calling srand_mac we use a weak seed dependent on the mac address. If present, use a RNG device instead to incerase entropy. Signed-off-by: Matthias Brugger Reviewed-by: Torsten Duwe --- Changes in v3: - use IS_ENABLED instead of #if Changes in v2: - fix dm_rng_read() parameters - add missing include file net/net_rand.h | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) diff --git a/net/net_rand.h b/net/net_rand.h index 4bf9bd817e..6a52cda85e 100644 --- a/net/net_rand.h +++ b/net/net_rand.h @@ -10,6 +10,8 @@ #define __NET_RAND_H__ #include +#include +#include /* * Return a seed for the PRNG derived from the eth0 MAC address. @@ -37,7 +39,22 @@ static inline unsigned int seed_mac(void) */ static inline void srand_mac(void) { - srand(seed_mac()); + int ret; + struct udevice *devp; + u32 randv = 0; + + if (IS_ENABLED(CONFIG_DM_RNG)) { + ret = uclass_get_device(UCLASS_RNG, 0, &devp); + if (ret) { + ret = dm_rng_read(devp, &randv, sizeof(randv)); + if (ret < 0) + randv = 0; + } + } + if (randv) + srand(randv); + else + srand(seed_mac()); } #endif /* __NET_RAND_H__ */