Re: [PATCH] KEYS: asym_tpm: Switch to get_random_bytes()

[Jerry Snitselaar]

On Thu Sep 26 19, Jarkko Sakkinen wrote:
> Only the kernel random pool should be used for generating random numbers.
> TPM contributes to that pool among the other sources of entropy. In here it
> is not, agreed, absolutely critical because TPM is what is trusted anyway
> but in order to remove tpm_get_random() we need to first remove all the
> call sites.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 0c36264aa1d5 ("KEYS: asym_tpm: Add loadkey2 and flushspecific [ver #2]")
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
> ---
> crypto/asymmetric_keys/asym_tpm.c | 7 ++-----
> 1 file changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/crypto/asymmetric_keys/asym_tpm.c b/crypto/asymmetric_keys/asym_tpm.c
> index 76d2ce3a1b5b..c14b8d186e93 100644
> --- a/crypto/asymmetric_keys/asym_tpm.c
> +++ b/crypto/asymmetric_keys/asym_tpm.c
> @@ -6,6 +6,7 @@
> #include <linux/kernel.h>
> #include <linux/seq_file.h>
> #include <linux/scatterlist.h>
> +#include <linux/random.h>
> #include <linux/tpm.h>
> #include <linux/tpm_command.h>
> #include <crypto/akcipher.h>
> @@ -54,11 +55,7 @@ static int tpm_loadkey2(struct tpm_buf *tb,
> 	}
>
> 	/* generate odd nonce */
> -	ret = tpm_get_random(NULL, nonceodd, TPM_NONCE_SIZE);
> -	if (ret < 0) {
> -		pr_info("tpm_get_random failed (%d)\n", ret);
> -		return ret;
> -	}
> +	get_random_bytes(nonceodd, TPM_NONCE_SIZE);
>
> 	/* calculate authorization HMAC value */
> 	ret = TSS_authhmac(authdata, keyauth, SHA1_DIGEST_SIZE, enonce,
> --
> 2.20.1

Should tpm_unbind and tpm_sign in asym_tpm.c be switched as well then?