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

Petr Vorel
2020-08-04T04:35:04Z

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)