On Wed, 2019-10-30 at 18:19 -0700, Lakshmi Ramasubramanian wrote:
> Asymmetric keys used for verifying file signatures or certificates
> are currently not included in the IMA measurement list.
>
> This patch defines a new IMA hook namely ima_post_key_create_or_update()
> to measure asymmetric keys.
It's not enough for the kernel to be able to compile the kernel after
applying all the patches in a patch set. After applying each patch,
the kernel should build properly, otherwise it is not bi-sect safe.
Refer to "3) Separate your changes" of
"Documentation/process/submitting-patches.rst.
>
> Signed-off-by: Lakshmi Ramasubramanian <nramas@xxxxxxxxxxxxxxxxxxx>
> ---
> security/integrity/ima/ima.h | 2 ++
> security/integrity/ima/ima_main.c | 26 ++++++++++++++++++++++++++
> 2 files changed, 28 insertions(+)
>
> diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
> index 997a57137351..22d0628faf56 100644
> --- a/security/integrity/ima/ima.h
> +++ b/security/integrity/ima/ima.h
> @@ -21,6 +21,8 @@
> #include <linux/tpm.h>
> #include <linux/audit.h>
> #include <crypto/hash_info.h>
> +#include <crypto/public_key.h>
> +#include <keys/asymmetric-type.h>
>
> #include "../integrity.h"
>
> diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
> index 492b8f241d39..18e1bc105be7 100644
> --- a/security/integrity/ima/ima_main.c
> +++ b/security/integrity/ima/ima_main.c
> @@ -635,6 +635,9 @@ void process_buffer_measurement(const void *buf, int size,
> int action = 0;
> u32 secid;
>
> + if (!ima_policy_flag)
> + return;
> +
> if (func) {
> security_task_getsecid(current, &secid);
> action = ima_get_action(NULL, current_cred(), secid, 0, func,
> @@ -695,6 +698,29 @@ void ima_kexec_cmdline(const void *buf, int size)
> }
> }
>
> +/**
> + * ima_post_key_create_or_update - measure asymmetric keys
> + * @keyring: keyring to which the key is linked to
> + * @key: created or updated key
> + * @flags: key flags
> + * @create: flag indicating whether the key was created or updated
> + *
> + * Keys can only be measured, not appraised.
> + */
> +void ima_post_key_create_or_update(struct key *keyring, struct key *key,
> + unsigned long flags, bool create)
> +{
> + const struct public_key *pk;
> +
> + if (key->type != &key_type_asymmetric)
> + return;
> +
> + pk = key->payload.data[asym_crypto];
> + process_buffer_measurement(pk->key, pk->keylen,
> + keyring->description,
> + NONE, 0);
This patch should also define the new "func".
Mimi
> +}
> +
> static int __init init_ima(void)
> {
> int error;
