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From: Oleksij Rempel <o.rempel@pengutronix.de>
To: barebox@lists.infradead.org
Cc: Oleksij Rempel <o.rempel@pengutronix.de>,
	Steffen Trumtrar <s.trumtrar@pengutronix.de>
Subject: [PATCH v1 3/3] lib: random: get_random_bytes from HWRNG if present
Date: Mon, 13 Mar 2017 14:42:28 +0100	[thread overview]
Message-ID: <20170313134228.32521-3-o.rempel@pengutronix.de> (raw)
In-Reply-To: <20170313134228.32521-1-o.rempel@pengutronix.de>

From: Steffen Trumtrar <s.trumtrar@pengutronix.de>

Instead of generating pseudo random numbers, get random bytes
from an optional HW generator, if enabled and registered.

Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
---
 lib/random.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/lib/random.c b/lib/random.c
index 210fea994..ff82dd1be 100644
--- a/lib/random.c
+++ b/lib/random.c
@@ -1,5 +1,6 @@
 #include <common.h>
 #include <stdlib.h>
+#include <linux/hw_random.h>
 
 static unsigned int random_seed;
 
@@ -22,6 +23,24 @@ void get_random_bytes(void *_buf, int len)
 {
 	char *buf = _buf;
 
+	if (IS_ENABLED(CONFIG_HWRNG)) {
+		struct hwrng *rng;
+		int bytes;
+
+		rng = hwrng_get_first();
+		if (!PTR_ERR(rng)) {
+			while (len) {
+				bytes = hwrng_get_data(rng, _buf, len, 0);
+				if (!bytes)
+					goto sw_fallback;
+				len -= bytes;
+			}
+
+			return;
+		}
+	}
+
+sw_fallback:
 	while (len--)
 		*buf++ = rand() % 256;
 }
-- 
2.11.0


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  parent reply	other threads:[~2017-03-13 13:42 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-13 13:42 [PATCH v1 1/3] drivers: add simple hw_random implementation Oleksij Rempel
2017-03-13 13:42 ` [PATCH v1 2/3] hw_random: add driver for Freescale RNGC Oleksij Rempel
2017-03-13 13:42 ` Oleksij Rempel [this message]
2017-03-14  7:55 ` [PATCH v1 1/3] drivers: add simple hw_random implementation Sascha Hauer

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