diff options
| author | Marek Behún <kabel@kernel.org> | 2025-04-22 11:57:18 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-05-02 07:39:30 +0200 |
| commit | ea3ee9994300790dd3324281f30d313e2a08e3c7 (patch) | |
| tree | 95614e34231eeaf554224e674262c1f180e61538 | |
| parent | 348adceb91b2adf888599d2cc5f95b68b09f7008 (diff) | |
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: <stable@vger.kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
| -rw-r--r-- | drivers/crypto/atmel-sha204a.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/crypto/atmel-sha204a.c b/drivers/crypto/atmel-sha204a.c index c96c14e7dab1..0ef92109ce22 100644 --- a/drivers/crypto/atmel-sha204a.c +++ b/drivers/crypto/atmel-sha204a.c @@ -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) |