[PATCH v1 5/6] KEYS: measure queued keys

Lakshmi Ramasubramanian
2019-10-23T00:18:31Z

Call process_buffer_measurement to measure keys that
are added and updated in the system.

Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
---
security/integrity/ima/ima_main.c | 23 +++++++++++++++++++++
security/integrity/ima/ima_queue.c | 32 ++++++++++++++++++++++++++++++
2 files changed, 55 insertions(+)

diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 8e965d18fb21..7c2afb954f19 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -678,6 +678,29 @@ void ima_kexec_cmdline(const void *buf, int size)
}
}

+/*
+ * ima_post_key_create_or_update
+ * @keyring points to the keyring to which the key belongs
+ * @key points to the key being created or updated
+ * @cred cred structure
+ * @flags flags passed to key_create_or_update function
+ * @create flag to indicate whether the key was created or updated
+ *
+ * IMA hook called when a new key is created or updated.
+ *
+ * On success return 0.
+ * Return appropriate error code on error
+ */
+int ima_post_key_create_or_update(struct key *keyring, struct key *key,
+ const struct cred *cred,
+ unsigned long flags, bool create)
+{
+ if (key->type != &key_type_asymmetric)
+ return 0;
+
+ return ima_measure_key(keyring, key);
+}
+
static int __init init_ima(void)
{
int error;
diff --git a/security/integrity/ima/ima_queue.c b/security/integrity/ima/ima_queue.c
index a262e289615b..0da11a292f99 100644
--- a/security/integrity/ima/ima_queue.c
+++ b/security/integrity/ima/ima_queue.c
@@ -322,7 +322,12 @@ static struct ima_trusted_key_entry *ima_alloc_trusted_queue_entry(
int ima_measure_key(struct key *keyring, struct key *key)
{
int rc = 0;
+ int pcr = CONFIG_IMA_MEASURE_PCR_IDX;
+ struct ima_template_desc *template_desc = ima_template_desc_current();
+ int action;
struct ima_trusted_key_entry *entry = NULL;
+ const struct public_key *pk;
+ u32 secid;
enum ima_hooks func;
bool queued = false;

@@ -344,16 +349,43 @@ int ima_measure_key(struct key *keyring, struct key *key)

mutex_unlock(&ima_trusted_keys_mutex);

+ if ((rc == 0) && !queued) {
+ security_task_getsecid(current, &secid);
+ action = ima_get_action(NULL, current_cred(), secid, 0,
+ func, &pcr, &template_desc);
+ if (action & IMA_MEASURE) {
+ pk = key->payload.data[asym_crypto];
+ process_buffer_measurement(pk->key, pk->keylen,
+ key->description,
+ pcr, template_desc);
+ }
+ }
+
return rc;
}

void ima_measure_queued_trusted_keys(void)
{
struct ima_trusted_key_entry *entry, *tmp;
+ int pcr = CONFIG_IMA_MEASURE_PCR_IDX;
+ struct ima_template_desc *template_desc = ima_template_desc_current();
+ int action;
+ u32 secid;

mutex_lock(&ima_trusted_keys_mutex);

list_for_each_entry_safe(entry, tmp, &ima_trusted_keys, list) {
+ security_task_getsecid(current, &secid);
+ action = ima_get_action(NULL, current_cred(), secid, 0,
+ entry->func, &pcr,
+ &template_desc);
+ if (action & IMA_MEASURE) {
+ process_buffer_measurement(entry->public_key,
+ entry->public_key_len,
+ entry->key_description,
+ pcr,
+ template_desc);
+ }
list_del(&entry->list);
ima_free_trusted_key_entry(entry);
}
--
2.17.1