From: Mauro Carvalho Chehab [mailto:mchehab+huawei@kernel.org] Sent: Wednesday, July 28, 2021 1:10 PM Em Mon, 26 Jul 2021 18:36:49 +0200 Roberto Sassu roberto.sassu@huawei.com escreveu:
Add an overview of DIGLIM to
Documentation/security/diglim/introduction.rst
and the architecture to Documentation/security/diglim/architecture.rst
Signed-off-by: Roberto Sassu roberto.sassu@huawei.com
.../security/diglim/architecture.rst | 45 ++ Documentation/security/diglim/index.rst | 11 + .../security/diglim/introduction.rst | 631 ++++++++++++++++++ Documentation/security/index.rst | 1 + MAINTAINERS | 9 + 5 files changed, 697 insertions(+) create mode 100644 Documentation/security/diglim/architecture.rst create mode 100644 Documentation/security/diglim/index.rst create mode 100644 Documentation/security/diglim/introduction.rst
diff --git a/Documentation/security/diglim/architecture.rst
b/Documentation/security/diglim/architecture.rst
new file mode 100644 index 000000000000..a54fe2453715 --- /dev/null +++ b/Documentation/security/diglim/architecture.rst @@ -0,0 +1,45 @@ +.. SPDX-License-Identifier: GPL-2.0
+Architecture +============
+This section introduces the high level architecture of DIGLIM.
+::
- add/delete from hash table and add refs to digest list
+---------------------------------------------+| +-----+ +-------------+ +--+| | key |-->| digest refs |-->...-->| |V +-----+ +-------------+ +--+- +-------------+ +-----+ +-------------+
- | digest list | | key |-->| digest refs |
- | (compact) | +-----+ +-------------+
- +-------------+ +-----+ +-------------+
^ 4. copy to | key |-->| digest refs || kernel memory +-----+ +-------------+ kernel space
^ ^ user space|<----------------+ 3b. upload |- +-------------+ +------------+ | 6. query digest
- | digest list | | user space | 2b. convert
- | (compact) | | parser |
- +-------------+ +------------+
- 1a. upload ^ 1b. read
|+------------+| RPM header |+------------++As mentioned before, digest lists can be uploaded directly if they are in
"before"? This is at the beginning of this document ;-)
You should probably add a reference to introduction.rst here, like:
As mentioned at Documentation/security/diglim/introduction.rst, ...
Hi Mauro
ok.
+the compact format (step 1a) or can be uploaded indirectly by the user +space parser if they are in an alternative format (steps 1b-3b).
+During upload, the kernel makes a copy of the digest list to the kernel +memory (step 4), and creates the necessary structures to index the digests +(hash table and a linked list of digest list references to locate the +digests in the digest list) (step 5).
+Finally, digests can be searched from user space through a securityfs file +(step 6) or by the kernel itself.
This probably applies to Documentation/security as a hole, but the best is to split the documents on two separate parts:
- the kAPI and internals;
- the admin-guide part.
The audience for the admin-guide is distribution pagagers and syssadmins.
Ok. I will create an admin-guide.
diff --git a/Documentation/security/diglim/index.rst
b/Documentation/security/diglim/index.rst
new file mode 100644 index 000000000000..0fc5ab019bc0 --- /dev/null +++ b/Documentation/security/diglim/index.rst @@ -0,0 +1,11 @@ +.. SPDX-License-Identifier: GPL-2.0
+====================================== +Digest Lists Integrity Module (DIGLIM) +======================================
+.. toctree::
- :maxdepth: 1
- introduction
- architecture
diff --git a/Documentation/security/diglim/introduction.rst
b/Documentation/security/diglim/introduction.rst
new file mode 100644 index 000000000000..d8d8b2a17222 --- /dev/null +++ b/Documentation/security/diglim/introduction.rst @@ -0,0 +1,631 @@ +.. SPDX-License-Identifier: GPL-2.0
+Introduction +============
+Digest Lists Integrity Module (DIGLIM) is a new component added to the +integrity subsystem in the kernel, primarily aiming to aid Integrity
I would replace:
"is a new component added to" -> "is a component of"
As this is the kind of text that tends to be outdated with time... Imagine someone reading this paragraph maybe 10 years in the future ;-)
Ok.
+Measurement Architecture (IMA) in the process of checking the integrity of +file content and metadata. It accomplishes this task by storing reference +values coming from software vendors and by reporting whether or not the +digest of file content or metadata calculated by IMA (or EVM) is found +among those values. In this way, IMA can decide, depending on the result
of
+a query, if a measurement should be taken or access to the file should be +granted. The `Security Assumptions`_ section explains more in detail why +this component has been placed in the kernel.
+The main benefits of using IMA in conjunction with DIGLIM are the ability +to implement advanced remote attestation schemes based on the usage of
a
+TPM key for establishing a TLS secure channel [1][2], and to reduce the +burden on Linux distribution vendors to extend secure boot at OS level to +applications.
+DIGLIM does not have the complexity of feature-rich databases. In fact, its +main functionality comes from the hash table primitives already in the +kernel. It does not have an ad-hoc storage module, it just indexes data in +a fixed format (digest lists, a set of concatenated digests preceded by a +header), copied to kernel memory as they are. Lastly, it does not support +database-oriented languages such as SQL, but only accepts a digest and its +algorithm as a query.
+The only digest list format supported by DIGLIM is called ``compact``. +However, Linux distribution vendors don't have to generate new digest lists +in this format for the packages they release, as already available +information, such as RPM headers and DEB package metadata, can be
already
+used as a source for reference values (they already include file digests),
-ETOMANY_already
as "already" available... can be "already" ... "already" include...
I would simplify the above text removing such redundancy.
Ok.
+with a user space parser taking care of the conversion to the compact +format.
+Although one might perceive that storing file or metadata digests for a +Linux distribution would significantly increase the memory usage, this does +not seem to be the case. As an anticipation of the evaluation done in the +`Preliminary Performance Evaluation`_ section, protecting binaries and +shared libraries of a minimal Fedora 33 installation requires 208K of +memory for the digest lists plus 556K for indexing.
+In exchange for a slightly increased memory usage, DIGLIM improves the +performance of the integrity subsystem. In the considered scenario, IMA +measurement and appraisal with digest lists requires respectively less than +one quarter and less than half the time, compared to the current solution.
I found this paragraph a little bit confusing to understand. Could you please improve the description?
I mean:
what improved by one quarter? what improved by "less than half of the time"?
Ok. I didn't want to make the text too heavy. The tests are described in the Preliminary Performance Evaluation section.
+DIGLIM also keeps track of whether digest lists have been processed in
some
+way (e.g. measured or appraised by IMA). This is important for example for +remote attestation, so that remote verifiers understand what has been +uploaded to the kernel.
+DIGLIM behaves like a transactional database, i.e. it has the ability to +roll back to the beginning of the transaction if an error occurred during +the addition of a digest list (the deletion operation always succeeds).
I don't think it makes sense to compare it with a transactional database.
I would say, instead, something like:
The inserts on DIGLIM are atomic: if an error occurs during the addition of a digest list, it rolls back the entire insert operation.
Ok, better.
+This capability has been tested with an ad-hoc fault injection mechanism +capable of simulating failures during the operations.
+Finally, DIGLIM exposes to user space, through securityfs, the digest lists +currently loaded, the number of digests added, a query interface and an +interface to set digest list labels.
+[1] LSS EU 2019
+- slides:
https://static.sched.com/hosted_files/lsseu2019/bd/secure_attested_commu nication_channels_lss_eu_2019.pdf
+- video: https://youtu.be/mffdQgkvDNY
+[2] FutureTPM EU project, final review meeting demo
+- slides:
Device-Management-Use-Case-HWDU.pdf
+- video: https://vimeo.com/528251864/4c1d55abcd
The above won't generate any cross-references with Sphinx.
For it correct syntax, see: https://www.sphinx- doc.org/en/master/usage/restructuredtext/basics.html#citations
Ok, will fix it.
+Binary Integrity +----------------
+Integrity is a fundamental security property in information systems.
+Integrity could be described as the condition in which a generic +component is just after it has been released by the entity that created it.
Sounds a weird description for me. (ISC)2 defines integrity on its glossary[1] as:
"Guarding against improper information modification or destruction and includes ensuring information non-repudiation and authenticity."
[1] https://www.isc2.org/Certifications/CISSP/CISSP-Student-Glossary
Ok, I meant integrity in the context of trusted computing.
https://trustedcomputinggroup.org/wp-content/uploads/IWG_ArchitecturePartII_...
In general the term "integrity" is used to denote the pristine state of a component (page 13).
+One way to check whether a component is in this condition (called binary +integrity) is to calculate its digest and to compare it with a reference +value (i.e. the digest calculated in controlled conditions, when the +component is released).
+IMA, a software part of the integrity subsystem, can perform such +evaluation and execute different actions:
+- store the digest in an integrity-protected measurement list, so that it
- can be sent to a remote verifier for analysis;
+- compare the calculated digest with a reference value (usually protected
- with a signature) and deny operations if the file is found corrupted;
+- store the digest in the system log.
+Contribution +------------
I would rename this chapter to "Benefits".
Ok.
+DIGLIM further enhances the capabilities offered by IMA-based solutions +and, at the same time, makes them more practical to adopt by reusing +existing sources as reference values for integrity decisions.
+Possible sources for digest lists are:
+- RPM headers; +- Debian repository metadata.
+Benefits for IMA Measurement +~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+One of the issues that arises when files are measured by the OS is that, +due to parallel execution, the order in which file accesses happen cannot +be predicted. Since the TPM Platform Configuration Register (PCR) extend +operation, executed after each file measurement, cryptographically binds +the current measurement to the previous ones, the PCR value at the end of
a
+workload cannot be predicted too.
+Thus, even if the usage of a TPM key, bound to a PCR value, should be +allowed when only good files were accessed, the TPM could unexpectedly
deny
+an operation on that key if files accesses did not happen as stated by the +key policy (which allows only one of the possible sequences).
+DIGLIM solves this issue by making the PCR value stable over the time and +not dependent on file accesses. The following figure depicts the current +and the new approaches:
+::
- IMA measurement list (current)
- entry# 1st boot 2nd boot 3rd boot
+----+---------------+ +----+---------------+ +----+---------------+- 1: | 10 | file1 measur. | | 10 | file3 measur. | | 10 | file2 measur. |
+----+---------------+ +----+---------------+ +----+---------------+- 2: | 10 | file2 measur. | | 10 | file2 measur. | | 10 | file3 measur. |
+----+---------------+ +----+---------------+ +----+---------------+- 3: | 10 | file3 measur. | | 10 | file1 measur. | | 10 | file4 measur. |
+----+---------------+ +----+---------------+ +----+---------------+- PCR: Extend != Extend != Extend
file1, file2, file3 file3, file2, file1 file2, file3, file4- PCR Extend definition:
PCR(new value) = Hash(Hash(meas. entry), PCR(previous value))+A new entry in the measurement list is created by IMA for each file access. +Assuming that ``file1``, ``file2`` and ``file3`` are files provided by the +software vendor, ``file4`` is an unknown file, the first two PCR values +above represent a good system state, the third a bad system state. The PCR +values are the result of the PCR extend operation performed for each +measurement entry with the digest of the measurement entry as an input.
+::
- IMA measurement list (with DIGLIM)
- dlist
- +--------------+
- | header |
- +--------------+
- | file1 digest |
- | file2 digest |
- | file3 digest |
- +--------------+
+``dlist`` is a digest list containing the digest of ``file1``, ``file2`` +and ``file3``. In the intended scenario, it is generated by a software +vendor at the end of the building process, and retrieved by the +administrator of the system where the digest list is loaded.
+::
- entry# 1st boot 2nd boot 3rd boot
+----+---------------+ +----+---------------+ +----+---------------+- 0: | 11 | dlist measur. | | 11 | dlist measur. | | 11 | dlist measur. |
+----+---------------+ +----+---------------+ +----+---------------+- 1: < file1 measur. skip > < file3 measur. skip > < file2 measur. skip >
- 2: < file2 measur. skip > < file2 measur. skip > < file3 measur. skip >
+----+---------------+- 3: < file3 measur. skip > < file1 measur. skip > | 11 | file4 measur. |
+----+---------------+- PCR: Extend = Extend != Extend
dlist dlist dlist, file4+The first entry in the measurement list contains the digest of the digest +list uploaded to the kernel at kernel initialization time.
+When a file is accessed, IMA queries DIGLIM with the calculated file digest +and, if it is found, IMA skips the measurement.
+Thus, the only information sent to remote verifiers are: the list of +files that could possibly be accessed (from the digest list), but not if +they were accessed and when; the measurement of unknown files.
+Despite providing less information, this solution has the advantage that +the good system state (i.e. when only ``file1``, ``file2`` and ``file3`` +are accessed) now can be represented with a deterministic PCR value (the +PCR is extended only with the measurement of the digest list). Also, the +bad system state can still be distinguished from the good state (the PCR is +extended also with the measurement of ``file4``).
+If a TPM key is bound to the good PCR value, the TPM would allow the key
to
+be used if ``file1``, ``file2`` or ``file3`` are accessed, regardless of +the sequence in which they are accessed (the PCR value does not change), +and would revoke the permission when the unknown ``file4`` is accessed
(the
+PCR value changes). If a system is able to establish a TLS connection with +a peer, this implicitly means that the system was in a good state (i.e. +``file4`` was not accessed, otherwise the TPM would have denied the usage +of the TPM key due to the key policy).
+Benefits for IMA Appraisal +~~~~~~~~~~~~~~~~~~~~~~~~~~
+Extending secure boot to applications means being able to verify the +provenance of files accessed. IMA does it by verifying file signatures with +a key that it trusts, which requires Linux distribution vendors to +additionally include in the package header a signature for each file that +must be verified (there is the dedicated ``RPMTAG_FILESIGNATURES``
section
+in the RPM header).
+The proposed approach would be instead to verify data provenance from +already available metadata (file digests) in existing packages. IMA would +verify the signature of package metadata and search file digests extracted +from package metadata and added to the hash table in the kernel.
+For RPMs, file digests can be found in the ``RPMTAG_FILEDIGESTS`` section +of ``RPMTAG_IMMUTABLE``, whose signature is in
``RPMTAG_RSAHEADER``. For
+DEBs, file digests (unsafe to use due to a weak digest algorithm) can be +found in the ``md5sum`` file, which can be indirectly verified from +``Release.gpg``.
+The following figure highlights the differences between the current and the +proposed approach.
+::
- IMA appraisal (current solution, with file signatures):
appraise+-----------+V |- +-------------------------+-----+ +-------+-----+ |
- | RPM header | | ima rpm | file1 | sig | |
- | ... | | plugin +-------+-----+ +-----+
- | file1 sig [to be added] | sig |--------> ... | IMA |
- | ... | | +-------+-----+ +-----+
- | fileN sig [to be added] | | | fileN | sig |
- +-------------------------+-----+ +-------+-----+
+In this case, file signatures must be added to the RPM header, so that the +``ima`` rpm plugin can extract them together with the file content. The
RPM
+header signature is not used.
+::
- IMA appraisal (with DIGLIM):
kernel hash tablewith RPM header content+---+ +--------------+| |--->| file1 digest |+---+ +--------------+...+---+ appraise (file1)| | <--------------+- +----------------+-----+ +---+ |
- | RPM header | | ^ |
- | ... | | digest_list | |
- | file1 digest | sig | rpm plugin | +-------+ +-----+
- | ... | |-------------+--->| file1 | | IMA |
- | fileN digest | | +-------+ +-----+
- +----------------+-----+ |
^ |+------------------------------------+appraise (RPM header)+In this case, the RPM header is used as it is, and its signature is used +for IMA appraisal. Then, the ``digest_list`` rpm plugin executes the user +space parser to parse the RPM header and add the extracted digests to an +hash table in the kernel. IMA appraisal of the files in the RPM package +consists in searching their digest in the hash table.
+Other than reusing available information as digest list, another advantage +is the lower computational overhead compared to the solution with file +signatures (only one signature verification for many files and digest +lookup, instead of per file signature verification, see `Preliminary +Performance Evaluation`_ for more details).
+Lifecycle +---------
+The lifecycle of DIGLIM is represented in the following figure:
+::
You could just use:
The lifecycle of DIGLIM is represented in the following figure::
- Vendor premises (release process with modifications):
- +------------+ +-----------------------+ +------------------------+
- | 1. build a | | 2. generate and sign | | 3. publish the package |
- | package |-->| a digest list from |-->| and digest list in |
- | | | packaged files | | a repository |
- +------------+ +-----------------------+ +------------------------+
||- User premises: |
V- +---------------------+ +------------------------+ +-----------------+
- | 6. use digest lists | | 5. download the digest | | 4. download and |
- | for measurement |<--| list and upload to |<--| install the |
- | and/or appraisal | | the kernel | | package |
- +---------------------+ +------------------------+ +-----------------+
+The figure above represents all the steps when a digest list is +generated separately. However, as mentioned in `Contribution`_, in most +cases existing packages can be already used as a source for digest lists, +limiting the effort for software vendors.
+If, for example, RPMs are used as a source for digest lists, the figure +above becomes:
+::
Same here.
Ok.
Thanks
Roberto
HUAWEI TECHNOLOGIES Duesseldorf GmbH, HRB 56063 Managing Director: Li Peng, Li Jian, Shi Yanli
- Vendor premises (release process without modifications):
- +------------+ +------------------------+
- | 1. build a | | 2. publish the package |
- | package |-->| in a repository |---------------------+
- | | | | |
- +------------+ +------------------------+ |
||- User premises: |
V- +---------------------+ +------------------------+ +-----------------+
- | 5. use digest lists | | 4. extract digest list | | 3. download and |
- | for measurement |<--| from the package |<--| install the |
- | and/or appraisal | | and upload to the | | package |
- | | | kernel | | |
- +---------------------+ +------------------------+ +-----------------+
+Step 4 can be performed with the ``digest_list`` rpm plugin and the user +space parser, without changes to rpm itself.
+Security Assumptions +--------------------
+As mentioned in the `Introduction`_, DIGLIM will be primarily used in +conjunction with IMA to enforce a mandatory policy on all user space +processes, including those owned by root. Even root, in a system with a +locked-down kernel, cannot affect the enforcement of the mandatory
policy
+or, if changes are permitted, it cannot do so without being detected.
+Given that the target of the enforcement are user space processes, DIGLIM +cannot be placed in the target, as a Mandatory Access Control (MAC)
design
+is required to have the components responsible to enforce the mandatory +policy separated from the target.
+While locking-down a system and limiting actions with a mandatory policy
is
+generally perceived by users as an obstacle, it has noteworthy benefits for +the users themselves.
+First, it would timely block attempts by malicious software to steal or +misuse user assets. Although users could query the package managers to +detect them, detection would happen after the fact, or it wouldn't happen +at all if the malicious software tampered with package managers. With a +mandatory policy enforced by the kernel, users would still be able to +decide which software they want to be executed except that, unlike
package
+managers, the kernel is not affected by user space processes or root.
+Second, it might make systems more easily verifiable from outside, due to +the limited actions the system allows. When users connect to a server, not +only they would be able to verify the server identity, which is already +possible with communication protocols like TLS, but also if the software +running on that server can be trusted to handle their sensitive data.
+Adoption +--------
+A former version of DIGLIM is used in the following OSes:
+- openEuler 20.09
+- openEuler 21.03
+Originally, DIGLIM was part of IMA (known as IMA Digest Lists). In this +version, it has been redesigned as a standalone module with an API that +makes its functionality accessible by IMA and, eventually, other +subsystems.
+User Space Support +------------------
+Digest lists can be generated and managed with ``digest-list-tools``:
+https://github.com/openeuler-mirror/digest-list-tools
+It includes two main applications:
+- ``gen_digest_lists``: generates digest lists from files in the
- filesystem or from the RPM database (more digest list sources can be
- supported);
+- ``manage_digest_lists``: converts and uploads digest lists to the
- kernel.
+Integration with rpm is done with the ``digest_list`` plugin:
+https://gitee.com/src-openeuler/rpm/blob/master/Add-digest-list-
plugin.patch
+This plugin writes the RPM header and its signature to a file, so that the +file is ready to be appraised by IMA, and calls the user space parser to +convert and upload the digest list to the kernel.
+Simple Usage Example (Tested with Fedora 33) +--------------------------------------------
+1. Digest list generation (RPM headers and their signature are copied to
- the specified directory):
+.. code-block:: bash
- # mkdir /etc/digest_lists
- # gen_digest_lists -t file -f rpm+db -d /etc/digest_lists -o add
+2. Digest list upload with the user space parser:
+.. code-block:: bash
- # manage_digest_lists -p add-digest -d /etc/digest_lists
+3. First digest list query:
+.. code-block:: bash
- # echo sha256-$(sha256sum /bin/cat) >
/sys/kernel/security/integrity/diglim/digest_query
- # cat /sys/kernel/security/integrity/diglim/digest_query
- sha256-[...]-0-file_list-rpm-coreutils-8.32-18.fc33.x86_64 (actions: 0):
version: 1, algo: sha256, type: 2, modifiers: 1, count: 106, datalen: 3392
+4. Second digest list query:
+.. code-block:: bash
- # echo sha256-$(sha256sum /bin/zip) >
/sys/kernel/security/integrity/diglim/digest_query
- # cat /sys/kernel/security/integrity/diglim/digest_query
- sha256-[...]-0-file_list-rpm-zip-3.0-27.fc33.x86_64 (actions: 0): version: 1,
algo: sha256, type: 2, modifiers: 1, count: 4, datalen: 128
+Preliminary Performance Evaluation +----------------------------------
+This section provides an initial estimation of the overhead introduced by +DIGLIM. The estimation has been performed on a Fedora 33 virtual machine +with 1447 packages installed. The virtual machine has 16 vCPU (host CPU: +AMD Ryzen Threadripper PRO 3955WX 16-Cores) and 2G of RAM (host
memory:
+64G). The virtual machine also has a vTPM with libtpms and swtpm as +backend.
+After writing the RPM headers to files, the size of the directory +containing them is 36M.
+After converting the RPM headers to the compact digest list, the size of +the data being uploaded to the kernel is 3.6M.
+The time to load the entire RPM database is 0.628s.
+After loading the digest lists to the kernel, the slab usage due to +indexing is (obtained with slab_nomerge in the kernel command line):
+::
- OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
- 118144 118144 100% 0,03K 923 128 3692K
digest_list_item_ref_cache
- 102400 102400 100% 0,03K 800 128 3200K digest_item_cache
- 2646 2646 100% 0,09K 63 42 252K digest_list_item_cache
+The stats, obtained from the ``digests_count`` interface, introduced later, +are:
+::
- Parser digests: 0
- File digests: 99100
- Metadata digests: 0
- Digest list digests: 1423
+On this installation, this would be the worst case in which all files are +measured and/or appraised, which is currently not recommended without +enforcing an integrity policy protecting mutable files. Infoflow LSM is a +component to accomplish this task:
integrity/cover/20190818235745.1417-1-roberto.sassu@huawei.com/
+The first manageable goal of IMA with DIGLIM is to use an execution policy, +with measurement and/or appraisal of files executed or mapped in memory
as
+executable (in addition to kernel modules and firmware). In this +case, the digest list contains the digest only for those files. The numbers +above change as follows.
+After converting the RPM headers to the compact digest list, the size of +the data being uploaded to the kernel is 208K.
+The time to load the digest of binaries and shared libraries is 0.062s.
+After loading the digest lists to the kernel, the slab usage due to +indexing is:
+::
- OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
- 7168 7168 100% 0,03K 56 128 224K digest_list_item_ref_cache
- 7168 7168 100% 0,03K 56 128 224K digest_item_cache
- 1134 1134 100% 0,09K 27 42 108K digest_list_item_cache
+The stats, obtained from the ``digests_count`` interface, are:
+::
- Parser digests: 0
- File digests: 5986
- Metadata digests: 0
- Digest list digests: 1104
+Comparison with IMA +~~~~~~~~~~~~~~~~~~~
+This section compares the performance between the current solution for
IMA
+measurement and appraisal, and IMA with DIGLIM.
+Workload A (without DIGLIM):
+#. cat file[0-5985] > /dev/null
+Workload B (with DIGLIM):
+#. echo $PWD/0-file_list-compact-file[0-1103] >
<securityfs>/integrity/diglim/digest_list_add
+#. cat file[0-5985] > /dev/null
+Workload A execution time without IMA policy:
+::
- real 0m0,155s
- user 0m0,008s
- sys 0m0,066s
+Measurement +...........
+IMA policy:
+::
- measure fowner=2000 func=FILE_CHECK mask=MAY_READ
use_diglim=allow pcr=11 ima_template=ima-sig
+``use_diglim`` is a policy keyword not yet supported by IMA.
+Workload A execution time with IMA and 5986 files with signature
measured:
+::
- real 0m8,273s
- user 0m0,008s
- sys 0m2,537s
+Workload B execution time with IMA, 1104 digest lists with signature +measured and uploaded to the kernel, and 5986 files with signature
accessed
+but not measured (due to the file digest being found in the hash table):
+::
- real 0m1,837s
- user 0m0,036s
- sys 0m0,583s
+Appraisal +.........
+IMA policy:
+::
- appraise fowner=2000 func=FILE_CHECK mask=MAY_READ
use_diglim=allow
+``use_diglim`` is a policy keyword not yet supported by IMA.
+Workload A execution time with IMA and 5986 files with file signature +appraised:
+::
- real 0m2,197s
- user 0m0,011s
- sys 0m2,022s
+Workload B execution time with IMA, 1104 digest lists with signature +appraised and uploaded to the kernel, and with 5986 files with signature +not verified (due to the file digest being found in the hash table):
+::
- real 0m0,982s
- user 0m0,020s
- sys 0m0,865s
diff --git a/Documentation/security/index.rst
b/Documentation/security/index.rst
index 16335de04e8c..6c3aea41c55b 100644 --- a/Documentation/security/index.rst +++ b/Documentation/security/index.rst @@ -17,3 +17,4 @@ Security Documentation tpm/index digsig landlock
- diglim/index
diff --git a/MAINTAINERS b/MAINTAINERS index 6c8be735cc91..c914dadd7e65 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -5452,6 +5452,15 @@ L: linux-gpio@vger.kernel.org S: Maintained F: drivers/gpio/gpio-gpio-mm.c
+DIGLIM +M: Roberto Sassu roberto.sassu@huawei.com +L: linux-integrity@vger.kernel.org +S: Supported +T: git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity.git +F: Documentation/security/diglim/architecture.rst +F: Documentation/security/diglim/index.rst +F: Documentation/security/diglim/introduction.rst
DIOLAN U2C-12 I2C DRIVER M: Guenter Roeck linux@roeck-us.net L: linux-i2c@vger.kernel.org
Thanks, Mauro