On Mon, Jun 15, 2020 at 04:41:34PM -0300, Bruno Meneguele wrote: > On Thu, May 28, 2020 at 06:05:27PM +0200, Petr Vorel wrote: > > Hi Mimi, > > ... > > > > > With just this change, the ima_tpm.sh test is failing.  I assume it is > > > > > failing because it is reading the SHA1 TPM bank, not the SHA256 bank > > > > > to calculate the boot_aggregate hash. > > > > First question: is it correct to take sha256? Because on my test below it's > > > > reading sha1, because that's the content of /sys/kernel/security/ima/ascii_runtime_measurements > > > > > > I thought just kernel commit: 6f1a1d103b48 ima: ("Switch to ima_hash_algo for > > > > boot aggregate") from current linux-integrity tree is needed, but I tested it on > > > > b59fda449cf0 ("ima: Set again build_ima_appraise variable") (i.e. having all > > > > Robeto's ima patches, missing just last 2 commits from next-integrity head). > > > > What is needed to get your setup? > > > > > This isn't a configuration problem, but an issue of reading PCRs and > > > calculating the TPM bank appropriate boot_aggregate.  If you're > > > calculating a sha256 boot_aggregate, then the test needs to read and > > > calculate the boot_aggregate by reading the SHA256 TPM bank. > > OK, I tested it on TPM 1.2 (no TPM 2.0 available atm). > > I guess you have TPM 2.0, that's why I didn't spot this issue. > > > > To sum that: my patch is required for any system without physical TPM with with > > kernel with b59fda449cf0 + it also works for TPM 1.2 (regardless kernel > > version), because TPM 1.2 supports sha1 only boot aggregate. > > > > But testing on kernel with b59fda449cf0 with TPM 2.0 is not only broken with > > this patch, but also on current version in master, right? As you have > > sha256:3fd5dc717f886ff7182526efc5edc3abb179a5aac1ab589c8ec888398233ae5 anyway. > > So this patch would help at least testing on VM without vTPM. > > > > If we consider to delay this change until we have the ima-evm-utils > released with the ima_boot_aggregate + make this test dependent on > both ima-evm-utils and tsspcrread, would it be worth to SKIP the test in > case a TPM2.0 sha256 bank is detected instead of FAIL? Thus we could > have the test fixed for TPM1.2 && no-TPM cases until we get the full > support for multiple banks? > > > ... > > > > > The ima-evm-utils next-testing branch has code to calculate the > > > > > boot_aggregate based on multiple banks. > > > > I see, 696bf0b ("ima-evm-utils: calculate the digests for multiple TPM banks") > > > > I wonder whether it's reasonable trying to port that to ima_boot_aggregate.c or > > > > just depend on evmctl. External dependencies are sometimes complicated, but for > > > > IMA I incline to just require evmctl. > > > > > Unlike TPM 1.2, the TPM 2.0 device driver doesn't export the TPM PCRs. > > >  Not only would you have a dependency on ima-evm-utils, but also on a > > > userspace application(s) for reading the TPM PCRs.  That dependency > > > exists whether you're using evmctl to calculate the boot_aggregate or > > > doing it yourself. > > Hm, things get complicated. > > Yep I remember your patch to skip verifying TPM 2.0 PCR values > > https://patchwork.ozlabs.org/project/ltp/patch/1558041162.3971.2.camel@linux.ibm.com/ > > At least thanks to Jerry Snitselaar since v5.6 we have > > /sys/class/tpm/tpm*/tpm_version_major. We could check this (+ try also > > /sys/class/tpm/tpm0/device/description for older kernels). > > > > BTW on my system there is also /sys/class/tpm/tpm0/ppi/version, which has 1.2, > > not sure if it indicate TPM 1.2, but I wouldn't rely on that. > > > > IIUC 'tpm_version_major' should be the only safe reference of the actual > TCG spec version being implemented by the hw TPM, in a sysfs standard > output. > > > ... > > > > > There's also a new test to verify the boot_aggregate. > > > > > > > $ VERBOSE=1 make check TESTS=boog_aggregate.test ^^^^ boot That's the issue :). > > > > BTW I got some errors > > > > ... > > > > make check-TESTS > > > > make[2]: Entering directory '/home/foo/ima-evm-utils/tests' > > > > make[3]: Entering directory '/home/foo/ima-evm-utils/tests' > > > > make[4]: Entering directory '/home/foo/ima-evm-utils/tests' > > > > make[4]: Nothing to be done for 'boog_aggregate.log'. > > > > make[4]: Leaving directory '/home/foo/ima-evm-utils/tests' > > > > fatal: making test-suite.log: failed to create boog_aggregate.trs > > > > fatal: making test-suite.log: failed to create boog_aggregate.log > > > > make[3]: *** [Makefile:516: test-suite.log] Error 1 > > > > make[3]: Leaving directory '/home/foo/ima-evm-utils/tests' > > > > make[2]: *** [Makefile:625: check-TESTS] Error 2 > > > > make[2]: Leaving directory '/home/foo/ima-evm-utils/tests' > > > > make[1]: *** [Makefile:692: check-am] Error 2 > > > > make[1]: Leaving directory '/home/foo/ima-evm-utils/tests' > > > > make: *** [Makefile:514: check-recursive] Error 1 > > > > > [Cc'ing Vitaly] > > > > > The boot_aggregate.trs and boot_aggregate.log files are being created > > > in the tests/ directory.  Is that directory read-only? > > Yes, drwxr-xr-x. Testing on fresh clone and issue persists. > > > > Yes, same thing here.. but didn't really check the reason for that. Will > take a time later to see what's happening. > > > > > > Both need some review and testing before being released. > > > > Any estimation when code is released? > > > > > Probably not before the next open window, but definitely before it is > > > released. > > Thanks for info. > > > > -- > bmeneg > PGP Key: http://bmeneg.com/pubkey.txt -- bmeneg PGP Key: http://bmeneg.com/pubkey.txt