Message ID | 93740b6b42e67caa2a1854520b7e68f0966e5024.camel@HansenPartnership.com (mailing list archive) |
---|---|
State | New |
Headers | show |
Series | add integrity and security to TPM2 transactions | expand |
Hi James, I love your patch! Perhaps something to improve: [auto build test WARNING on char-misc/char-misc-testing] [also build test WARNING on char-misc/char-misc-next char-misc/char-misc-linus herbert-cryptodev-2.6/master linus/master v6.2-rc8 next-20230217] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/James-Bottomley/crypto-lib-implement-library-version-of-AES-in-CFB-mode/20230217-044329 patch link: https://lore.kernel.org/r/93740b6b42e67caa2a1854520b7e68f0966e5024.camel%40HansenPartnership.com patch subject: [PATCH 11/12] tpm: add the null key name as a sysfs export config: nios2-randconfig-m041-20230217 (https://download.01.org/0day-ci/archive/20230217/202302171852.zpg5jNaj-lkp@intel.com/config) compiler: nios2-linux-gcc (GCC) 12.1.0 reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://github.com/intel-lab-lkp/linux/commit/4c35ecc57dfd3fd82341cd20dfc30c5f665ba952 git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review James-Bottomley/crypto-lib-implement-library-version-of-AES-in-CFB-mode/20230217-044329 git checkout 4c35ecc57dfd3fd82341cd20dfc30c5f665ba952 # save the config file mkdir build_dir && cp config build_dir/.config COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=nios2 olddefconfig COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=nios2 SHELL=/bin/bash drivers/char/tpm/ If you fix the issue, kindly add following tag where applicable | Reported-by: kernel test robot <lkp@intel.com> | Link: https://lore.kernel.org/oe-kbuild-all/202302171852.zpg5jNaj-lkp@intel.com/ All warnings (new ones prefixed by >>): >> drivers/char/tpm/tpm-sysfs.c:344:5: warning: "CONFIG_TPM_BUS_SECURITY" is not defined, evaluates to 0 [-Wundef] 344 | #if CONFIG_TPM_BUS_SECURITY | ^~~~~~~~~~~~~~~~~~~~~~~ vim +/CONFIG_TPM_BUS_SECURITY +344 drivers/char/tpm/tpm-sysfs.c 341 342 static struct attribute *tpm2_dev_attrs[] = { 343 &dev_attr_tpm_version_major.attr, > 344 #if CONFIG_TPM_BUS_SECURITY 345 &dev_attr_null_name.attr, 346 #endif 347 NULL 348 }; 349
diff --git a/drivers/char/tpm/tpm-sysfs.c b/drivers/char/tpm/tpm-sysfs.c index 54c71473aa29..6044a2765da2 100644 --- a/drivers/char/tpm/tpm-sysfs.c +++ b/drivers/char/tpm/tpm-sysfs.c @@ -309,6 +309,21 @@ static ssize_t tpm_version_major_show(struct device *dev, } static DEVICE_ATTR_RO(tpm_version_major); +#ifdef CONFIG_TPM_BUS_SECURITY +static ssize_t null_name_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct tpm_chip *chip = to_tpm_chip(dev); + int size = TPM2_NAME_SIZE; + + bin2hex(buf, chip->tpmkeyname, size); + size *= 2; + buf[size++] = '\n'; + return size; +} +static DEVICE_ATTR_RO(null_name); +#endif + static struct attribute *tpm1_dev_attrs[] = { &dev_attr_pubek.attr, &dev_attr_pcrs.attr, @@ -326,6 +341,9 @@ static struct attribute *tpm1_dev_attrs[] = { static struct attribute *tpm2_dev_attrs[] = { &dev_attr_tpm_version_major.attr, +#if CONFIG_TPM_BUS_SECURITY + &dev_attr_null_name.attr, +#endif NULL };
This is the last component of encrypted tpm2 session handling that allows us to verify from userspace that the key derived from the NULL seed genuinely belongs to the TPM and has not been spoofed. The procedure for doing this involves creating an attestation identity key (which requires verification of the TPM EK certificate) and then using that AIK to sign a certification of the Elliptic Curve key over the NULL seed. Userspace must create this EC Key using the parameters prescribed in TCG TPM v2.0 Provisioning Guidance for the SRK ECC; if this is done correctly the names will match and the TPM can then run a TPM2_Certify operation on this derived primary key using the newly created AIK. Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com> --- drivers/char/tpm/tpm-sysfs.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)