crypto: atmel-sha204a - Set hwrng quality to lowest possible
PATCH 1/1 crypto: atmel-sha204a - Set hwrng quality to lowest possible
commit 8006aff15516a170640239c5a8e6696c0ba18d8e upstream.
According to the review by Bill Cox [1], the Atmel SHA204A random number generator produces random numbers with very low entropy.
Set the lowest possible entropy for this chip just to be safe.
[1] https://www.metzdowd.com/pipermail/cryptography/2014-December/023858.html
Fixes da001fb651b00e1d ("crypto: atmel-i2c - add support for SHA204A random number generator")
Cc <[email protected]>
Signed-off-by Marek Behún <[email protected]>
Acked-by Ard Biesheuvel <[email protected]>
Reviewed-by Linus Walleij <[email protected]>
Signed-off-by Herbert Xu <[email protected]>
[ rebased for 5.15 ]
Signed-off-by Marek Behún <[email protected]>
--- drivers/crypto/atmel-sha204a.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
drivers/crypto/atmel-sha204a.c +6 -1
@@ -107,7 +107,12 @@ static int atmel_sha204a_probe(struct i2c_client *client, i2c_priv->hwrng.name =dev_name (&client->dev); i2c_priv->hwrng.read = atmel_sha204a_rng_read; - i2c_priv->hwrng.quality =1024 ; + +/* +* According to review by Bill Cox [1], this HWRNG has very low entropy. +* [1] https://www.metzdowd.com/pipermail/cryptography/2014-December/023858.html +*/ + i2c_priv->hwrng.quality =1 ; ret =devm_hwrng_register (&client->dev, &i2c_priv->hwrng);if (ret)
Signature · 1 line
2.49.0