Re: [PATCH] ima_evm_utils: extended calc_bootaggr to PCRs 8 - 9

From: Mimi Zohar <zohar@linux.ibm.com>
To: Maurizio Drocco <maurizio.drocco@ibm.com>, roberto.sassu@huawei.com
Cc: Silviu.Vlasceanu@huawei.com, dmitry.kasatkin@gmail.com,
	jejb@linux.ibm.com, jmorris@namei.org,
	linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-security-module@vger.kernel.org, serge@hallyn.com,
	mdrocco@linux.vnet.ibm.com
Subject: Re: [PATCH] ima_evm_utils: extended calc_bootaggr to PCRs 8 - 9
Date: Mon, 22 Jun 2020 16:14:31 -0400	[thread overview]
Message-ID: <1592856871.4987.21.camel@linux.ibm.com> (raw)
In-Reply-To: <20200618201126.2081-2-maurizio.drocco@ibm.com>

On Thu, 2020-06-18 at 16:11 -0400, Maurizio Drocco wrote:
> From: Maurizio <maurizio.drocco@ibm.com>
> 
> If PCRs 8 - 9 are set (i.e. not all-zeros), cal_bootaggr should include
> them into the digest.
> 
> Signed-off-by: Maurizio Drocco <maurizio.drocco@ibm.com>
> ---
>  src/evmctl.c | 16 +++++++++++++++-
>  1 file changed, 15 insertions(+), 1 deletion(-)
> 
> diff --git a/src/evmctl.c b/src/evmctl.c
> index 1d065ce..554571e 100644
> --- a/src/evmctl.c
> +++ b/src/evmctl.c
> @@ -1930,6 +1930,18 @@ static void calc_bootaggr(struct tpm_bank_info *bank)
>  		}
>  	}
>  
> +	if (strcmp(bank->algo_name, "sha1") != 0) {
> +		for (i = 8; i < 10; i++) {
> +			if (memcmp(bank->pcr[i], zero, bank->digest_size) != 0) {
> +				err = EVP_DigestUpdate(pctx, bank->pcr[i], bank->digest_size);
> +				if (!err) {
> +					log_err("EVP_DigestUpdate() failed\n");
> +					return;
> +				}
> +			}
> +		}
> +	}

Roberto, now that we're only including the PCRs 8 & 9 in the non-sha1
"boot_aggregate", they can always be included.

Please reflect this change in the patch description and, here, in the
code.

thanks,

Mimi