diff mbox series

ima_evm_utils: extended calc_bootaggr to PCRs 8 - 9

Message ID 20200618201126.2081-2-maurizio.drocco@ibm.com (mailing list archive)
State New, archived
Headers show
Series ima_evm_utils: extended calc_bootaggr to PCRs 8 - 9 | expand

Commit Message

Maurizio Drocco June 18, 2020, 8:11 p.m. UTC
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(-)

Comments

Mimi Zohar June 22, 2020, 8:14 p.m. UTC | #1
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
diff mbox series

Patch

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;
+				}
+			}
+		}
+	}
+
 	err = EVP_DigestFinal(pctx, bank->digest, &mdlen);
 	if (!err) {
 		log_err("EVP_DigestFinal() failed\n");
@@ -1973,7 +1985,9 @@  static int append_bootaggr(char *bootaggr, struct tpm_bank_info *tpm_banks)
  * The IMA measurement list boot_aggregate is the link between the preboot
  * event log and the IMA measurement list.  Read and calculate all the
  * possible per TPM bank boot_aggregate digests based on the existing
- * PCRs 0 - 7 to validate against the IMA boot_aggregate record.
+ * PCRs 0 - 9 to validate against the IMA boot_aggregate record. If PCRs
+ * 8 - 9 are not set (i.e. all-zeros) or the digest algorithm is SHA1, only
+ * PCRs 0 - 7 are considered.
  */
 static int cmd_ima_bootaggr(struct command *cmd)
 {