Re: [PATCH 1/3] IMA: Update key test documentation

Lachlan Sneff
2020-08-04T16:42:52Z

Hi Petr,
Thanks for updating the readme. Should I send a new patch with
the changes you have proposed?

Thanks,
Lachlan

On 8/4/20 12:35 AM, Petr Vorel wrote:
> Hi Lachlan,
>
>> The current documentation for the existing IMA key test was
>> left in by accident by a previous merge. It does not apply
>> to the test that is currently included in the LTP.
>> Update the documentation for the IMA key test.
> Reviewed-by: Petr Vorel <petr.vorel@gmail.com>
> Thanks for fixing this, I propose this changes:
>
> Fixes: d2768c84e ("IMA: Add a test to verify measurement of keys")
>
>> ---
>> .../kernel/security/integrity/ima/README.md | 22 +++++--------------
>> 1 file changed, 5 insertions(+), 17 deletions(-)
>> diff --git a/testcases/kernel/security/integrity/ima/README.md b/testcases/kernel/security/integrity/ima/README.md
>> index d4644ba39..2956ac7fd 100644
>> --- a/testcases/kernel/security/integrity/ima/README.md
>> +++ b/testcases/kernel/security/integrity/ima/README.md
>> @@ -15,27 +15,15 @@ Although a custom policy, loaded via dracut, systemd or manually from user
>> space, may contain equivalent measurement tcb rules, detecting them would
>> require `IMA_READ_POLICY=y` therefore ignore this option.
>> -### IMA key import test
>> -`ima_keys.sh` requires a x509 public key, by default in `/etc/keys/x509_ima.der`
>> -(defined in `CONFIG_IMA_X509_PATH` kernel config option).
>> -The key must be signed by the private key you generate. Follow these instructions:
>> -https://manpages.ubuntu.com/manpages/disco/man1/evmctl.1.html#generate%20trusted%20keys
>> -
>> -The test cannot be set-up automatically because the x509 public key must be
>> -built into the kernel and loaded onto a trusted keyring
>> -(e.g. `.builtin_trusted_keys`, `.secondary_trusted_keyring`).
>> -
>> -As well as what's required for the IMA tests, the following are also required
>> -in the kernel configuration:
>> +### IMA key test
>> +`ima_keys.sh` requires a readable IMA policy, as well as a loaded policy
>> +with `func=KEY_CHECK keyrings=...`, see example in `keycheck.policy`.
>> +
>> +Mandatory kernel configuration for IMA:
> This "Mandatory kernel configuration for IMA:" would be in docs twice. The above
> one (CONFIG_INTEGRITY=y, CONFIG_IMA=y) is required for all tests.
> Take it that "### IMA key test" is header 3, but ## IMA tests
> is header 2 (upper level).
>
>> ```
>> CONFIG_IMA_READ_POLICY=y
>> -CONFIG_IMA_X509_PATH="/etc/keys/x509_ima.der"
>> -CONFIG_SYSTEM_TRUSTED_KEYRING=y
>> -CONFIG_SYSTEM_TRUSTED_KEYS="/etc/keys/ima-local-ca.pem"
>> ```
>> -Test also requires loaded policy with `func=KEY_CHECK`, see example in `keycheck.policy`.
>> -
>> ### IMA kexec test
>> `ima_kexec.sh` requires loaded policy which contains `measure func=KEXEC_CMDLINE`,
> I also removed "IMA" from EVM tests header.
>
> Kind regards,
> Petr
>
> diff --git testcases/kernel/security/integrity/ima/README.md testcases/kernel/security/integrity/ima/README.md
> index 2956ac7fd..392e1e868 100644
> --- testcases/kernel/security/integrity/ima/README.md
> +++ testcases/kernel/security/integrity/ima/README.md
> @@ -19,7 +19,8 @@ require `IMA_READ_POLICY=y` therefore ignore this option.
> `ima_keys.sh` requires a readable IMA policy, as well as a loaded policy
> with `func=KEY_CHECK keyrings=...`, see example in `keycheck.policy`.
>
> -Mandatory kernel configuration for IMA:
> +As well as what's required for the IMA tests, the following are also required
> +-in the kernel configuration:
> ```
> CONFIG_IMA_READ_POLICY=y
> ```
> @@ -38,7 +39,7 @@ To kexec a different kernel image export `IMA_KEXEC_IMAGE=<pathname>`.
> kernel parameter) which appraises the integrity of all files owned by root and EVM setup.
> Again, for simplicity ignore possibility to load requires rules via custom policy.
>
> -Mandatory kernel configuration for IMA & EVM:
> +Mandatory kernel configuration for EVM tests:
> ```
> CONFIG_INTEGRITY=y
> CONFIG_INTEGRITY_SIGNATURE=y
> @@ -50,7 +51,7 @@ CONFIG_TRUSTED_KEYS=y
> CONFIG_ENCRYPTED_KEYS=y
> ```
>
> -Example of installing IMA + EVM on openSUSE:
> +Example of preparing environment on for EVM on openSUSE:
>
> * Boot install system with `ima_policy=tcb|appraise_tcb ima_appraise=fix evm=fix` kernel parameters
> (for IMA measurement, IMA appraisal and EVM protection)