The blacklist_init() function calls panic() for memory allocation
errors. This change documents the reason why we don't return -ENODEV.
Link: https://lore.kernel.org/r/20220322111323.542184-2-mic@digikod.net
Link: https://lore.kernel.org/r/YjeW2r6Wv55Du0bJ@iki.fi
Suggested-by: Paul Moore <paul@paul-moore.com>
Reviewed-by: Paul Moore <paul@paul-moore.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Add a kernel option SYSTEM_BLACKLIST_AUTH_UPDATE to enable the root user
to dynamically add new keys to the blacklist keyring. This enables to
invalidate new certificates, either from being loaded in a keyring, or
from being trusted in a PKCS#7 certificate chain. This also enables to
add new file hashes to be denied by the integrity infrastructure.
Being able to untrust a certificate which could have normaly been
trusted is a sensitive operation. This is why adding new hashes to the
blacklist keyring is only allowed when these hashes are signed and
vouched by the builtin trusted keyring. A blacklist hash is stored as a
key description. The PKCS#7 signature of this description must be
provided as the key payload.
Marking a certificate as untrusted should be enforced while the system
is running. It is then forbiden to remove such blacklist keys.
Update blacklist keyring, blacklist key and revoked certificate access
rights:
* allows the root user to search for a specific blacklisted hash, which
make sense because the descriptions are already viewable;
* forbids key update (blacklist and asymmetric ones);
* restricts kernel rights on the blacklist keyring to align with the
root user rights.
See help in tools/certs/print-cert-tbs-hash.sh .
Cc: David Howells <dhowells@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Eric Snowberg <eric.snowberg@oracle.com>
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>
Link: https://lore.kernel.org/r/20210712170313.884724-6-mic@digikod.net
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Tested-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Before exposing this new key type to user space, make sure that only
meaningful blacklisted hashes are accepted. This is also checked for
builtin blacklisted hashes, but a following commit make sure that the
user will notice (at built time) and will fix the configuration if it
already included errors.
Check that a blacklist key description starts with a valid prefix and
then a valid hexadecimal string.
Cc: David Howells <dhowells@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Eric Snowberg <eric.snowberg@oracle.com>
Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lore.kernel.org/r/20210712170313.884724-4-mic@digikod.net
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Factor out the blacklist hash creation with the get_raw_hash() helper.
This also centralize the "tbs" and "bin" prefixes and make them private,
which help to manage them consistently.
Cc: David Howells <dhowells@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Eric Snowberg <eric.snowberg@oracle.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>
Link: https://lore.kernel.org/r/20210712170313.884724-5-mic@digikod.net
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Align with the new macros and add appropriate include files.
Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>
KEY_FLAG_KEEP is not meant to be passed to keyring_alloc() or key_alloc(),
as these only take KEY_ALLOC_* flags. KEY_FLAG_KEEP has the same value as
KEY_ALLOC_BYPASS_RESTRICTION, but fortunately only key_create_or_update()
uses it. LSMs using the key_alloc hook don't check that flag.
KEY_FLAG_KEEP is then ignored but fortunately (again) the root user cannot
write to the blacklist keyring, so it is not possible to remove a key/hash
from it.
Fix this by adding a KEY_ALLOC_SET_KEEP flag that tells key_alloc() to set
KEY_FLAG_KEEP on the new key. blacklist_init() can then, correctly, pass
this to keyring_alloc().
We can also use this in ima_mok_init() rather than setting the flag
manually.
Note that this doesn't fix an observable bug with the current
implementation but it is required to allow addition of new hashes to the
blacklist in the future without making it possible for them to be removed.
Fixes: 734114f878 ("KEYS: Add a system blacklist keyring")
Reported-by: Mickaël Salaün <mic@linux.microsoft.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Mickaël Salaün <mic@linux.microsoft.com>
cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: David Woodhouse <dwmw2@infradead.org>
When looking for a blacklisted hash, bin2hex() is used to transform a
binary hash to an ascii (lowercase) hexadecimal string. This string is
then search for in the description of the keys from the blacklist
keyring. When adding a key to the blacklist keyring,
blacklist_vet_description() checks the hash prefix and the hexadecimal
string, but not that this string is lowercase. It is then valid to set
hashes with uppercase hexadecimal, which will be silently ignored by the
kernel.
Add an additional check to blacklist_vet_description() to check that
hexadecimal strings are in lowercase.
Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Ben Boeckel <mathstuf@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
certs/blacklist.c:84: warning: Function parameter or member 'hash' not
described in 'mark_hash_blacklisted'
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Ben Boeckel <mathstuf@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: keyrings@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
The -EKEYREJECTED error returned by existing is_hash_blacklisted() is
misleading when called for checking against blacklisted hash of a
binary.
This patch adds a wrapper function is_binary_blacklisted() to return
-EPERM error if binary is blacklisted.
Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1572492694-6520-7-git-send-email-zohar@linux.ibm.com
-----BEGIN PGP SIGNATURE-----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=E3bF
-----END PGP SIGNATURE-----
Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull keyring ACL support from David Howells:
"This changes the permissions model used by keys and keyrings to be
based on an internal ACL by the following means:
- Replace the permissions mask internally with an ACL that contains a
list of ACEs, each with a specific subject with a permissions mask.
Potted default ACLs are available for new keys and keyrings.
ACE subjects can be macroised to indicate the UID and GID specified
on the key (which remain). Future commits will be able to add
additional subject types, such as specific UIDs or domain
tags/namespaces.
Also split a number of permissions to give finer control. Examples
include splitting the revocation permit from the change-attributes
permit, thereby allowing someone to be granted permission to revoke
a key without allowing them to change the owner; also the ability
to join a keyring is split from the ability to link to it, thereby
stopping a process accessing a keyring by joining it and thus
acquiring use of possessor permits.
- Provide a keyctl to allow the granting or denial of one or more
permits to a specific subject. Direct access to the ACL is not
granted, and the ACL cannot be viewed"
* tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
keys: Provide KEYCTL_GRANT_PERMISSION
keys: Replace uid/gid/perm permissions checking with an ACL
-----BEGIN PGP SIGNATURE-----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=Push
-----END PGP SIGNATURE-----
Merge tag 'keys-namespace-20190627' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull keyring namespacing from David Howells:
"These patches help make keys and keyrings more namespace aware.
Firstly some miscellaneous patches to make the process easier:
- Simplify key index_key handling so that the word-sized chunks
assoc_array requires don't have to be shifted about, making it
easier to add more bits into the key.
- Cache the hash value in the key so that we don't have to calculate
on every key we examine during a search (it involves a bunch of
multiplications).
- Allow keying_search() to search non-recursively.
Then the main patches:
- Make it so that keyring names are per-user_namespace from the point
of view of KEYCTL_JOIN_SESSION_KEYRING so that they're not
accessible cross-user_namespace.
keyctl_capabilities() shows KEYCTL_CAPS1_NS_KEYRING_NAME for this.
- Move the user and user-session keyrings to the user_namespace
rather than the user_struct. This prevents them propagating
directly across user_namespaces boundaries (ie. the KEY_SPEC_*
flags will only pick from the current user_namespace).
- Make it possible to include the target namespace in which the key
shall operate in the index_key. This will allow the possibility of
multiple keys with the same description, but different target
domains to be held in the same keyring.
keyctl_capabilities() shows KEYCTL_CAPS1_NS_KEY_TAG for this.
- Make it so that keys are implicitly invalidated by removal of a
domain tag, causing them to be garbage collected.
- Institute a network namespace domain tag that allows keys to be
differentiated by the network namespace in which they operate. New
keys that are of a type marked 'KEY_TYPE_NET_DOMAIN' are assigned
the network domain in force when they are created.
- Make it so that the desired network namespace can be handed down
into the request_key() mechanism. This allows AFS, NFS, etc. to
request keys specific to the network namespace of the superblock.
This also means that the keys in the DNS record cache are
thenceforth namespaced, provided network filesystems pass the
appropriate network namespace down into dns_query().
For DNS, AFS and NFS are good, whilst CIFS and Ceph are not. Other
cache keyrings, such as idmapper keyrings, also need to set the
domain tag - for which they need access to the network namespace of
the superblock"
* tag 'keys-namespace-20190627' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
keys: Pass the network namespace into request_key mechanism
keys: Network namespace domain tag
keys: Garbage collect keys for which the domain has been removed
keys: Include target namespace in match criteria
keys: Move the user and user-session keyrings to the user_namespace
keys: Namespace keyring names
keys: Add a 'recurse' flag for keyring searches
keys: Cache the hash value to avoid lots of recalculation
keys: Simplify key description management
Replace the uid/gid/perm permissions checking on a key with an ACL to allow
the SETATTR and SEARCH permissions to be split. This will also allow a
greater range of subjects to represented.
============
WHY DO THIS?
============
The problem is that SETATTR and SEARCH cover a slew of actions, not all of
which should be grouped together.
For SETATTR, this includes actions that are about controlling access to a
key:
(1) Changing a key's ownership.
(2) Changing a key's security information.
(3) Setting a keyring's restriction.
And actions that are about managing a key's lifetime:
(4) Setting an expiry time.
(5) Revoking a key.
and (proposed) managing a key as part of a cache:
(6) Invalidating a key.
Managing a key's lifetime doesn't really have anything to do with
controlling access to that key.
Expiry time is awkward since it's more about the lifetime of the content
and so, in some ways goes better with WRITE permission. It can, however,
be set unconditionally by a process with an appropriate authorisation token
for instantiating a key, and can also be set by the key type driver when a
key is instantiated, so lumping it with the access-controlling actions is
probably okay.
As for SEARCH permission, that currently covers:
(1) Finding keys in a keyring tree during a search.
(2) Permitting keyrings to be joined.
(3) Invalidation.
But these don't really belong together either, since these actions really
need to be controlled separately.
Finally, there are number of special cases to do with granting the
administrator special rights to invalidate or clear keys that I would like
to handle with the ACL rather than key flags and special checks.
===============
WHAT IS CHANGED
===============
The SETATTR permission is split to create two new permissions:
(1) SET_SECURITY - which allows the key's owner, group and ACL to be
changed and a restriction to be placed on a keyring.
(2) REVOKE - which allows a key to be revoked.
The SEARCH permission is split to create:
(1) SEARCH - which allows a keyring to be search and a key to be found.
(2) JOIN - which allows a keyring to be joined as a session keyring.
(3) INVAL - which allows a key to be invalidated.
The WRITE permission is also split to create:
(1) WRITE - which allows a key's content to be altered and links to be
added, removed and replaced in a keyring.
(2) CLEAR - which allows a keyring to be cleared completely. This is
split out to make it possible to give just this to an administrator.
(3) REVOKE - see above.
Keys acquire ACLs which consist of a series of ACEs, and all that apply are
unioned together. An ACE specifies a subject, such as:
(*) Possessor - permitted to anyone who 'possesses' a key
(*) Owner - permitted to the key owner
(*) Group - permitted to the key group
(*) Everyone - permitted to everyone
Note that 'Other' has been replaced with 'Everyone' on the assumption that
you wouldn't grant a permit to 'Other' that you wouldn't also grant to
everyone else.
Further subjects may be made available by later patches.
The ACE also specifies a permissions mask. The set of permissions is now:
VIEW Can view the key metadata
READ Can read the key content
WRITE Can update/modify the key content
SEARCH Can find the key by searching/requesting
LINK Can make a link to the key
SET_SECURITY Can change owner, ACL, expiry
INVAL Can invalidate
REVOKE Can revoke
JOIN Can join this keyring
CLEAR Can clear this keyring
The KEYCTL_SETPERM function is then deprecated.
The KEYCTL_SET_TIMEOUT function then is permitted if SET_SECURITY is set,
or if the caller has a valid instantiation auth token.
The KEYCTL_INVALIDATE function then requires INVAL.
The KEYCTL_REVOKE function then requires REVOKE.
The KEYCTL_JOIN_SESSION_KEYRING function then requires JOIN to join an
existing keyring.
The JOIN permission is enabled by default for session keyrings and manually
created keyrings only.
======================
BACKWARD COMPATIBILITY
======================
To maintain backward compatibility, KEYCTL_SETPERM will translate the
permissions mask it is given into a new ACL for a key - unless
KEYCTL_SET_ACL has been called on that key, in which case an error will be
returned.
It will convert possessor, owner, group and other permissions into separate
ACEs, if each portion of the mask is non-zero.
SETATTR permission turns on all of INVAL, REVOKE and SET_SECURITY. WRITE
permission turns on WRITE, REVOKE and, if a keyring, CLEAR. JOIN is turned
on if a keyring is being altered.
The KEYCTL_DESCRIBE function translates the ACL back into a permissions
mask to return depending on possessor, owner, group and everyone ACEs.
It will make the following mappings:
(1) INVAL, JOIN -> SEARCH
(2) SET_SECURITY -> SETATTR
(3) REVOKE -> WRITE if SETATTR isn't already set
(4) CLEAR -> WRITE
Note that the value subsequently returned by KEYCTL_DESCRIBE may not match
the value set with KEYCTL_SETATTR.
=======
TESTING
=======
This passes the keyutils testsuite for all but a couple of tests:
(1) tests/keyctl/dh_compute/badargs: The first wrong-key-type test now
returns EOPNOTSUPP rather than ENOKEY as READ permission isn't removed
if the type doesn't have ->read(). You still can't actually read the
key.
(2) tests/keyctl/permitting/valid: The view-other-permissions test doesn't
work as Other has been replaced with Everyone in the ACL.
Signed-off-by: David Howells <dhowells@redhat.com>
Add a 'recurse' flag for keyring searches so that the flag can be omitted
and recursion disabled, thereby allowing just the nominated keyring to be
searched and none of the children.
Signed-off-by: David Howells <dhowells@redhat.com>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public licence as published by
the free software foundation either version 2 of the licence or at
your option any later version
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 114 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190520170857.552531963@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix typos and add the following to the scripts/spelling.txt:
intialisation||initialisation
intialised||initialised
intialise||initialise
This commit does not intend to change the British spelling itself.
Link: http://lkml.kernel.org/r/1481573103-11329-18-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add the following:
(1) A new system keyring that is used to store information about
blacklisted certificates and signatures.
(2) A new key type (called 'blacklist') that is used to store a
blacklisted hash in its description as a hex string. The key accepts
no payload.
(3) The ability to configure a list of blacklisted hashes into the kernel
at build time. This is done by setting
CONFIG_SYSTEM_BLACKLIST_HASH_LIST to the filename of a list of hashes
that are in the form:
"<hash>", "<hash>", ..., "<hash>"
where each <hash> is a hex string representation of the hash and must
include all necessary leading zeros to pad the hash to the right size.
The above are enabled with CONFIG_SYSTEM_BLACKLIST_KEYRING.
Once the kernel is booted, the blacklist keyring can be listed:
root@andromeda ~]# keyctl show %:.blacklist
Keyring
723359729 ---lswrv 0 0 keyring: .blacklist
676257228 ---lswrv 0 0 \_ blacklist: 123412341234c55c1dcc601ab8e172917706aa32fb5eaf826813547fdf02dd46
The blacklist cannot currently be modified by userspace, but it will be
possible to load it, for example, from the UEFI blacklist database.
A later commit will make it possible to load blacklisted asymmetric keys in
here too.
Signed-off-by: David Howells <dhowells@redhat.com>
