On Wed, Jun 24, 2020 at 05:17:52PM -0400, Stefan Berger wrote: > On 6/23/20 2:13 PM, Bruno Meneguele wrote: > > On Tue, Jun 23, 2020 at 02:01:22PM -0400, Maurizio Drocco wrote: > > > From: Maurizio <[email protected]> > > > > > > If PCRs 8 - 9 are set (i.e. not all-zeros), cal_bootaggr should include > > > them into the digest. > > > Wouldn't you have to check for not all-zeros in your code? >
boot_aggregate in kernel, after the following patch be applied: https://lkml.org/lkml/2020/6/23/833 is calculated regardless PCR 8 & 9 being zero or not. Thus evmctl is only reflecting the same behavior. I think it would be worth changing the commit log here. > > Stefan > > > > > > > > Signed-off-by: Maurizio Drocco <[email protected]> > > > --- > > > Changelog: > > > v2: > > > - Always include PCRs 8 & 9 to non-sha1 hashes > > > v1: > > > - Include non-zero PCRs 8 & 9 to boot aggregates > > > > > > src/evmctl.c | 15 +++++++++++++-- > > > 1 file changed, 13 insertions(+), 2 deletions(-) > > > > > > diff --git a/src/evmctl.c b/src/evmctl.c > > > index 1d065ce..46b7092 100644 > > > --- a/src/evmctl.c > > > +++ b/src/evmctl.c > > > @@ -1930,6 +1930,16 @@ static void calc_bootaggr(struct tpm_bank_info > > > *bank) > > > } > > > } > > > + if (strcmp(bank->algo_name, "sha1") != 0) { > > > + for (i = 8; i < 10; i++) { > > > + 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"); > > > @@ -1972,8 +1982,9 @@ 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. > > > + * possible per TPM bank boot_aggregate digests based on the existing > > > PCRs > > > + * 0 - 9 to validate against the IMA boot_aggregate record. If the digest > > > + * algorithm is SHA1, only PCRs 0 - 7 are considered to avoid ambiguity. > > > */ > > > static int cmd_ima_bootaggr(struct command *cmd) > > > { > > > -- > > > 2.17.1 > > > > > Reviewed-by: Bruno Meneguele <[email protected]> > > > -- bmeneg PGP Key: http://bmeneg.com/pubkey.txt
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