On Wed, 2019-11-13 at 10:46 -0800, Lakshmi Ramasubramanian wrote:
> Measure keys loaded onto any keyring.
>
> This patch defines a new IMA policy func namely KEY_CHECK to
> measure keys. Updated ima_match_rules() to check for KEY_CHECK
> and ima_parse_rule() to handle KEY_CHECK.
>
> Signed-off-by: Lakshmi Ramasubramanian <nramas@xxxxxxxxxxxxxxxxxxx>
> ---
> Documentation/ABI/testing/ima_policy | 6 +++++-
> security/integrity/ima/ima.h | 1 +
> security/integrity/ima/ima_main.c | 7 +++++++
> security/integrity/ima/ima_policy.c | 4 +++-
> 4 files changed, 16 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy
> index 29aaedf33246..066d32797500 100644
> --- a/Documentation/ABI/testing/ima_policy
> +++ b/Documentation/ABI/testing/ima_policy
> @@ -29,7 +29,7 @@ Description:
> base: func:= [BPRM_CHECK][MMAP_CHECK][CREDS_CHECK][FILE_CHECK][MODULE_CHECK]
> [FIRMWARE_CHECK]
> [KEXEC_KERNEL_CHECK] [KEXEC_INITRAMFS_CHECK]
> - [KEXEC_CMDLINE]
> + [KEXEC_CMDLINE] [KEY_CHECK]
> mask:= [[^]MAY_READ] [[^]MAY_WRITE] [[^]MAY_APPEND]
> [[^]MAY_EXEC]
> fsmagic:= hex value
> @@ -113,3 +113,7 @@ Description:
> Example of appraise rule allowing modsig appended signatures:
>
> appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig|modsig
> +
> + Example of measure rule using KEY_CHECK to measure all keys:
> +
> + measure func=KEY_CHECK
> diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
> index df4ca482fb53..fe6c698617bd 100644
> --- a/security/integrity/ima/ima.h
> +++ b/security/integrity/ima/ima.h
> @@ -193,6 +193,7 @@ static inline unsigned long ima_hash_key(u8 *digest)
> hook(KEXEC_INITRAMFS_CHECK) \
> hook(POLICY_CHECK) \
> hook(KEXEC_CMDLINE) \
> + hook(KEY_CHECK) \
> hook(MAX_CHECK)
> #define __ima_hook_enumify(ENUM) ENUM,
>
> diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
> index d7e987baf127..12684e8d7124 100644
> --- a/security/integrity/ima/ima_main.c
> +++ b/security/integrity/ima/ima_main.c
> @@ -655,6 +655,13 @@ void process_buffer_measurement(const void *buf, int size,
> int action = 0;
> u32 secid;
>
> + /*
> + * If IMA is not yet initialized or IMA policy is empty
> + * then there is no need to measure.
> + */
> + if (!ima_policy_flag)
> + return;
> +
This addition has nothing to do with defining a new IMA hook and
should be a separate patch. This can be posted independently of this
patch set.
Mimi
> /*
> * Both LSM hooks and auxilary based buffer measurements are
> * based on policy. To avoid code duplication, differentiate
> diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
> index f19a895ad7cd..1525a28fd705 100644
> --- a/security/integrity/ima/ima_policy.c
> +++ b/security/integrity/ima/ima_policy.c
> @@ -373,7 +373,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
> {
> int i;
>
> - if (func == KEXEC_CMDLINE) {
> + if ((func == KEXEC_CMDLINE) || (func == KEY_CHECK)) {
> if ((rule->flags & IMA_FUNC) && (rule->func == func))
> return true;
> return false;
> @@ -997,6 +997,8 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
> entry->func = POLICY_CHECK;
> else if (strcmp(args[0].from, "KEXEC_CMDLINE") == 0)
> entry->func = KEXEC_CMDLINE;
> + else if (strcmp(args[0].from, "KEY_CHECK") == 0)
> + entry->func = KEY_CHECK;
> else
> result = -EINVAL;
> if (!result)
