From: James Bottomley <James.Bottomley@HansenPartnership.com>
To: linux-integrity@vger.kernel.org
Cc: linux-crypto@vger.kernel.org,
linux-security-module@vger.kernel.org,
Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Subject: [PATCH v6 07/12] tpm2: add hmac checks to tpm2_pcr_extend()
Date: Mon, 09 Sep 2019 13:22:19 +0100 [thread overview]
Message-ID: <1568031739.6613.36.camel@HansenPartnership.com> (raw)
In-Reply-To: <1568031408.6613.29.camel@HansenPartnership.com>
We use tpm2_pcr_extend() in trusted keys to extend a PCR to prevent a
key from being re-loaded until the next reboot. To use this
functionality securely, that extend must be protected by a session
hmac.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
---
v3: add error handling to sessions
---
drivers/char/tpm/tpm2-cmd.c | 28 +++++++++++-----------------
1 file changed, 11 insertions(+), 17 deletions(-)
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index d120b0a260eb..0012657d3617 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -223,13 +223,6 @@ int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx,
return rc;
}
-struct tpm2_null_auth_area {
- __be32 handle;
- __be16 nonce_size;
- u8 attributes;
- __be16 auth_size;
-} __packed;
-
/**
* tpm2_pcr_extend() - extend a PCR value
*
@@ -243,24 +236,23 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
struct tpm_digest *digests)
{
struct tpm_buf buf;
- struct tpm2_null_auth_area auth_area;
+ struct tpm2_auth *auth;
int rc;
int i;
- rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_PCR_EXTEND);
+ rc = tpm2_start_auth_session(chip, &auth);
if (rc)
return rc;
- tpm_buf_append_u32(&buf, pcr_idx);
+ rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_PCR_EXTEND);
+ if (rc) {
+ tpm2_end_auth_session(auth);
+ return rc;
+ }
- auth_area.handle = cpu_to_be32(TPM2_RS_PW);
- auth_area.nonce_size = 0;
- auth_area.attributes = 0;
- auth_area.auth_size = 0;
+ tpm_buf_append_name(&buf, auth, pcr_idx, NULL);
+ tpm_buf_append_hmac_session(&buf, auth, 0, NULL, 0);
- tpm_buf_append_u32(&buf, sizeof(struct tpm2_null_auth_area));
- tpm_buf_append(&buf, (const unsigned char *)&auth_area,
- sizeof(auth_area));
tpm_buf_append_u32(&buf, chip->nr_allocated_banks);
for (i = 0; i < chip->nr_allocated_banks; i++) {
@@ -269,7 +261,9 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
chip->allocated_banks[i].digest_size);
}
+ tpm_buf_fill_hmac_session(&buf, auth);
rc = tpm_transmit_cmd(chip, &buf, 0, "attempting extend a PCR value");
+ rc = tpm_buf_check_hmac_response(&buf, auth, rc);
tpm_buf_destroy(&buf);
--
2.16.4
next prev parent reply other threads:[~2019-09-09 12:22 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-09 12:16 [PATCH v6 00/12] add integrity and security to TPM2 transactions James Bottomley
2019-09-09 12:17 ` [PATCH v6 01/12] tpm-buf: move from static inlines to real functions James Bottomley
2019-09-20 14:06 ` Jarkko Sakkinen
2019-09-20 14:06 ` Jarkko Sakkinen
2019-09-20 15:53 ` James Bottomley
2019-09-09 12:18 ` [PATCH v6 02/12] tpm-buf: add handling for TPM2B types James Bottomley
2019-09-20 14:18 ` Jarkko Sakkinen
2019-09-24 11:12 ` James Bottomley
2019-09-25 12:34 ` Jarkko Sakkinen
2019-09-25 12:34 ` Jarkko Sakkinen
2019-09-09 12:19 ` [PATCH v6 03/12] tpm-buf: add cursor based functions for response parsing James Bottomley
2019-09-09 12:19 ` [PATCH v6 04/12] tpm2-space: export the context save and load commands James Bottomley
2019-09-09 12:20 ` [PATCH v6 05/12] tpm2-sessions: Add full HMAC and encrypt/decrypt session handling James Bottomley
2019-09-20 14:34 ` Jarkko Sakkinen
2019-09-20 14:35 ` Jarkko Sakkinen
2019-09-24 11:18 ` James Bottomley
2019-09-09 12:21 ` [PATCH v6 06/12] tpm-buf: add tpm_buf_parameters() James Bottomley
2019-09-09 12:22 ` James Bottomley [this message]
2019-09-09 12:22 ` [PATCH v6 08/12] tpm2: add session encryption protection to tpm2_get_random() James Bottomley
2019-09-09 12:23 ` [PATCH v6 09/12] trusted keys: Add session encryption protection to the seal/unseal path James Bottomley
2019-09-09 12:24 ` [PATCH v6 10/12] tpm: add the null key name as a tpm2 sysfs variable James Bottomley
2019-09-09 12:25 ` [PATCH v6 11/12] Documentation: add tpm-security.rst James Bottomley
2019-09-09 12:26 ` [PATCH v6 12/12] tpm2-sessions: NOT FOR COMMITTING add sessions testing James Bottomley
2019-09-10 16:21 ` [PATCH v6 00/12] add integrity and security to TPM2 transactions Jarkko Sakkinen
2019-09-10 16:29 ` James Bottomley
2019-09-11 8:42 ` Jarkko Sakkinen
2019-09-11 9:40 ` Jarkko Sakkinen
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