linux.git/security/integrity/ima/ima.h, branch v5.8

ima: extend boot_aggregate with kernel measurements

2020-06-25T00:47:24+00:00

Registers 8-9 are used to store measurements of the kernel and its
command line (e.g., grub2 bootloader with tpm module enabled). IMA
should include them in the boot aggregate. Registers 8-9 should be
only included in non-SHA1 digests to avoid ambiguity.

Signed-off-by: Maurizio Drocco 
Reviewed-by: Bruno Meneguele 
Tested-by: Bruno Meneguele   (TPM 1.2, TPM 2.0)
Signed-off-by: Mimi Zohar

ima: Call ima_calc_boot_aggregate() in ima_eventdigest_init()

2020-06-03T21:20:43+00:00

If the template field 'd' is chosen and the digest to be added to the
measurement entry was not calculated with SHA1 or MD5, it is
recalculated with SHA1, by using the passed file descriptor. However, this
cannot be done for boot_aggregate, because there is no file descriptor.

This patch adds a call to ima_calc_boot_aggregate() in
ima_eventdigest_init(), so that the digest can be recalculated also for the
boot_aggregate entry.

Cc: stable@vger.kernel.org # 3.13.x
Fixes: 3ce1217d6cd5d ("ima: define template fields library and new helpers")
Reported-by: Takashi Iwai 
Signed-off-by: Roberto Sassu 
Signed-off-by: Mimi Zohar

ima: Fix ima digest hash table key calculation

2020-05-08T02:54:07+00:00

Function hash_long() accepts unsigned long, while currently only one byte
is passed from ima_hash_key(), which calculates a key for ima_htable.

Given that hashing the digest does not give clear benefits compared to
using the digest itself, remove hash_long() and return the modulus
calculated on the first two bytes of the digest with the number of slots.
Also reduce the depth of the hash table by doubling the number of slots.

Cc: stable@vger.kernel.org
Fixes: 3323eec921ef ("integrity: IMA as an integrity service provider")
Co-developed-by: Roberto Sassu 
Signed-off-by: Roberto Sassu 
Signed-off-by: Krzysztof Struczynski 
Acked-by: David.Laight@aculab.com (big endian system concerns)
Signed-off-by: Mimi Zohar

ima: Use ima_hash_algo for collision detection in the measurement list

2020-04-20T02:03:39+00:00

Before calculating a digest for each PCR bank, collisions were detected
with a SHA1 digest. This patch includes ima_hash_algo among the algorithms
used to calculate the template digest and checks collisions on that digest.

The position in the measurement entry array of the template digest
calculated with the IMA default hash algorithm is stored in the
ima_hash_algo_idx global variable and is determined at IMA initialization
time.

Signed-off-by: Roberto Sassu 
Signed-off-by: Mimi Zohar

ima: Switch to dynamically allocated buffer for template digests

2020-04-20T02:03:39+00:00

This patch dynamically allocates the array of tpm_digest structures in
ima_alloc_init_template() and ima_restore_template_data(). The size of the
array is equal to the number of PCR banks plus ima_extra_slots, to make
room for SHA1 and the IMA default hash algorithm, when PCR banks with those
algorithms are not allocated.

Calculating the SHA1 digest is mandatory, as SHA1 still remains the default
hash algorithm for the measurement list. When IMA will support the Crypto
Agile format, remaining digests will be also provided.

The position in the measurement entry array of the SHA1 digest is stored in
the ima_sha1_idx global variable and is determined at IMA initialization
time.

Signed-off-by: Roberto Sassu 
Signed-off-by: Mimi Zohar

ima: Store template digest directly in ima_template_entry

2020-04-20T02:03:39+00:00

In preparation for the patch that calculates a digest for each allocated
PCR bank, this patch passes to ima_calc_field_array_hash() the
ima_template_entry structure, so that digests can be directly stored in
that structure instead of ima_digest_data.

Signed-off-by: Roberto Sassu 
Signed-off-by: Mimi Zohar

IMA: Defined delayed workqueue to free the queued keys

2020-01-23T12:37:31+00:00

Keys queued for measurement should be freed if a custom IMA policy
was not loaded.  Otherwise, the keys will remain queued forever
consuming kernel memory.

This patch defines a delayed workqueue to handle the above scenario.
The workqueue handler is setup to execute 5 minutes after IMA
initialization is completed.

If a custom IMA policy is loaded before the workqueue handler is
scheduled to execute, the workqueue task is cancelled and any queued keys
are processed for measurement.  But if a custom policy was not loaded then
the queued keys are just freed when the delayed workqueue handler is run.

Signed-off-by: Lakshmi Ramasubramanian 
Reported-by: kernel test robot  # sleeping
function called from invalid context
Reported-by: kbuild test robot  # redefinition of
ima_init_key_queue() function.
Signed-off-by: Mimi Zohar

IMA: Define workqueue for early boot key measurements

2020-01-23T12:35:11+00:00

Measuring keys requires a custom IMA policy to be loaded.  Keys created
or updated before a custom IMA policy is loaded should be queued and
will be processed after a custom policy is loaded.

This patch defines a workqueue for queuing keys when a custom IMA policy
has not yet been loaded.  An intermediate Kconfig boolean option namely
IMA_QUEUE_EARLY_BOOT_KEYS is used to declare the workqueue functions.

A flag namely ima_process_keys is used to check if the key should be
queued or should be processed immediately.

Signed-off-by: Lakshmi Ramasubramanian 
Signed-off-by: Mimi Zohar

IMA: Add support to limit measuring keys

2019-12-12T13:53:50+00:00

Limit measuring keys to those keys being loaded onto a given set of
keyrings only and when the user id (uid) matches if uid is specified
in the policy.

This patch defines a new IMA policy option namely "keyrings=" that
can be used to specify a set of keyrings. If this option is specified
in the policy for "measure func=KEY_CHECK" then only the keys
loaded onto a keyring given in the "keyrings=" option are measured.

If uid is specified in the policy then the key is measured only if
the current user id matches the one specified in the policy.

Added a new parameter namely "keyring" (name of the keyring) to
process_buffer_measurement(). The keyring name is passed to
ima_get_action() to determine the required action.
ima_match_rules() is updated to check keyring in the policy, if
specified, for KEY_CHECK function.

Signed-off-by: Lakshmi Ramasubramanian 
Signed-off-by: Mimi Zohar

IMA: Add KEY_CHECK func to measure keys

2019-12-12T13:53:50+00:00

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 
Signed-off-by: Mimi Zohar