Re: [PATCH v4 01/10] IMA: Defined an IMA hook to measure keys on key create or update

From: Lakshmi Ramasubramanian
Date: Wed Nov 06 2019 - 19:21:25 EST



On 11/6/2019 2:43 PM, Mimi Zohar wrote:

+void ima_post_key_create_or_update(struct key *keyring, struct key *key,
+ unsigned long flags, bool create)
+{
+ if ((keyring != NULL) && (key != NULL))
+ return;

I would move the patch that defines the "keyring=" policy option prior
to this one. ÂInclude the call to process_buffer_measurement() in this
patch. ÂA subsequent patch would add support to defer measuring the
key, by calling a function named something like
ima_queue_key_measurement().

Mimi

As I'd stated in the other response, I wanted to isolate all key related code in a separate C file and build it if and only if all CONFIG dependencies are met.

I can do the following:

=> Define the IMA hook in ima_asymmetric_keys.c instead of ima_main.c

=> In include/linux/ima.h declare the IMA hook if CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS is enabled.
Else, NOP it.

#ifdef CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS
extern void ima_post_key_create_or_update(struct key *keyring,
struct key *key,
unsigned long flags,
bool create);
#else
static inline void ima_post_key_create_or_update(struct key *keyring,
struct key *key,
unsigned long flags,
bool create) {}
#endif

Would that be acceptable?

thanks,
-lakshmi