From: Maurizio Drocco <maurizio.drocco@ibm.com>
To: zohar@linux.ibm.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, maurizio.drocco@ibm.com,
mdrocco@linux.vnet.ibm.com, roberto.sassu@huawei.com,
serge@hallyn.com
Subject: [PATCH] ima: extend boot_aggregate with kernel measurements
Date: Mon, 22 Jun 2020 00:50:19 -0400 [thread overview]
Message-ID: <20200622045019.1636-1-maurizio.drocco@ibm.com> (raw)
In-Reply-To: <1592856871.4987.21.camel@linux.ibm.com>
IMA is not considering TPM registers 8-9 when calculating the boot
aggregate. When registers 8-9 are used to store measurements of the
kernel and its command line (e.g., grub2 bootloader with tpm module
enabled), IMA should include them in the boot aggregate. Registers
8-9 are only included in non-SHA1 boot_aggregate digests to avoid
ambiguity.
Signed-off-by: Maurizio Drocco <maurizio.drocco@ibm.com>
---
security/integrity/ima/ima.h | 2 +-
security/integrity/ima/ima_crypto.c | 15 ++++++++++++++-
2 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index df93ac258e01..9d94080bdad8 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -30,7 +30,7 @@
enum ima_show_type { IMA_SHOW_BINARY, IMA_SHOW_BINARY_NO_FIELD_LEN,
IMA_SHOW_BINARY_OLD_STRING_FMT, IMA_SHOW_ASCII };
-enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8 };
+enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8, TPM_PCR10 = 10 };
/* digest size for IMA, fits SHA1 or MD5 */
#define IMA_DIGEST_SIZE SHA1_DIGEST_SIZE
diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index 220b14920c37..d02917d85033 100644
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c
@@ -823,13 +823,26 @@ static int ima_calc_boot_aggregate_tfm(char *digest, u16 alg_id,
if (rc != 0)
return rc;
- /* cumulative sha1 over tpm registers 0-7 */
+ /* cumulative digest over tpm registers 0-7 */
for (i = TPM_PCR0; i < TPM_PCR8; i++) {
ima_pcrread(i, &d);
/* now accumulate with current aggregate */
rc = crypto_shash_update(shash, d.digest,
crypto_shash_digestsize(tfm));
}
+ /*
+ * extend cumulative digest over tpm registers 8-9, which contain
+ * measurement for the kernel command line (reg. 8) and image (reg. 9)
+ * in a typical PCR allocation. Registers 8-9 are only included in
+ * non-SHA1 boot_aggregate digests to avoid ambiguity.
+ */
+ if (alg_id != TPM_ALG_SHA1) {
+ for (i = TPM_PCR8; i < TPM_PCR10; i++) {
+ ima_pcrread(i, &d);
+ rc = crypto_shash_update(shash, d.digest,
+ crypto_shash_digestsize(tfm));
+ }
+ }
if (!rc)
crypto_shash_final(shash, digest);
return rc;
--
2.17.1
next prev parent reply other threads:[~2020-06-22 23:14 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-11 19:54 [PATCH] extend IMA boot_aggregate with kernel measurements Maurizio Drocco
2020-06-12 0:29 ` Mimi Zohar
2020-06-12 14:38 ` Maurizio Drocco
2020-06-12 15:11 ` Roberto Sassu
2020-06-12 17:14 ` James Bottomley
2020-06-16 17:29 ` Roberto Sassu
2020-06-16 18:11 ` Mimi Zohar
2020-06-18 12:38 ` Roberto Sassu
2020-06-18 20:11 ` Maurizio Drocco
2020-06-18 20:11 ` [PATCH] ima_evm_utils: extended calc_bootaggr to PCRs 8 - 9 Maurizio Drocco
2020-06-22 20:14 ` Mimi Zohar
2020-06-22 4:50 ` Maurizio Drocco [this message]
2020-06-23 14:03 ` [PATCH] ima: extend boot_aggregate with kernel measurements Mimi Zohar
2020-06-23 15:57 ` [PATCH v4] " Maurizio Drocco
2020-06-23 18:53 ` Bruno Meneguele
2020-06-23 18:01 ` [PATCH v2] ima_evm_utils: extended calc_bootaggr to PCRs 8 - 9 Maurizio Drocco
2020-06-23 18:13 ` Bruno Meneguele
2020-06-24 21:17 ` Stefan Berger
2020-06-24 21:33 ` [PATCH] " Maurizio Drocco
2020-06-24 21:33 ` [PATCH v2] " Bruno Meneguele
2020-06-24 21:35 ` [PATCH v3] " Maurizio Drocco
2020-06-24 21:50 ` Bruno Meneguele
2020-06-12 4:47 ` [PATCH] extend IMA boot_aggregate with kernel measurements kernel test robot
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200622045019.1636-1-maurizio.drocco@ibm.com \
--to=maurizio.drocco@ibm.com \
--cc=Silviu.Vlasceanu@huawei.com \
--cc=dmitry.kasatkin@gmail.com \
--cc=jejb@linux.ibm.com \
--cc=jmorris@namei.org \
--cc=linux-integrity@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=mdrocco@linux.vnet.ibm.com \
--cc=roberto.sassu@huawei.com \
--cc=serge@hallyn.com \
--cc=zohar@linux.ibm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).