Commit Graph

12 Commits

Author SHA1 Message Date
Dmitry Kasatkin
f4dc37785e integrity: define '.evm' as a builtin 'trusted' keyring
Require all keys added to the EVM keyring be signed by an
existing trusted key on the system trusted keyring.

This patch also switches IMA to use integrity_init_keyring().

Changes in v3:
* Added 'init_keyring' config based variable to skip initializing
  keyring instead of using  __integrity_init_keyring() wrapper.
* Added dependency back to CONFIG_IMA_TRUSTED_KEYRING

Changes in v2:
* Replace CONFIG_EVM_TRUSTED_KEYRING with IMA and EVM common
  CONFIG_INTEGRITY_TRUSTED_KEYRING configuration option
* Deprecate CONFIG_IMA_TRUSTED_KEYRING but keep it for config
  file compatibility. (Mimi Zohar)

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-11-23 14:30:02 -05:00
Dmitry Kasatkin
72e1eed8ab integrity: prevent loading untrusted certificates on the IMA trusted keyring
If IMA_LOAD_X509 is enabled, either directly or indirectly via
IMA_APPRAISE_SIGNED_INIT, certificates are loaded onto the IMA
trusted keyring by the kernel via key_create_or_update(). When
the KEY_ALLOC_TRUSTED flag is provided, certificates are loaded
without first verifying the certificate is properly signed by a
trusted key on the system keyring.  This patch removes the
KEY_ALLOC_TRUSTED flag.

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Cc:  <stable@vger.kernel.org> # 3.19+
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-10-09 15:31:18 -04:00
Dmitry Kasatkin
9d03a721a3 integrity: add validity checks for 'path' parameter
This patch adds validity checks for 'path' parameter and
makes it const.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-05-21 13:59:28 -04:00
Dmitry Kasatkin
65d543b233 integrity: provide a function to load x509 certificate from the kernel
Provide the function to load x509 certificates from the kernel into the
integrity kernel keyring.

Changes in v2:
* configuration option removed
* function declared as '__init'

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-11-17 23:11:59 -05:00
Dmitry Kasatkin
d16a8585d3 integrity: add missing '__init' keyword for integrity_init_keyring()
integrity_init_keyring() is used only from kernel '__init'
functions. Add it there as well.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-10-07 14:32:53 -04:00
Mimi Zohar
7d2ce2320e ima: define '.ima' as a builtin 'trusted' keyring
Require all keys added to the IMA keyring be signed by an
existing trusted key on the system trusted keyring.

Changelog v6:
- remove ifdef CONFIG_IMA_TRUSTED_KEYRING in C code - Dmitry
- update Kconfig dependency and help
- select KEYS_DEBUG_PROC_KEYS - Dmitry

Changelog v5:
- Move integrity_init_keyring() to init_ima() - Dmitry
- reset keyring[id] on failure - Dmitry

Changelog v1:
- don't link IMA trusted keyring to user keyring

Changelog:
- define stub integrity_init_keyring() function (reported-by Fengguang Wu)
- differentiate between regular and trusted keyring names.
- replace printk with pr_info (D. Kasatkin)
- only make the IMA keyring a trusted keyring (reported-by D. Kastatkin)
- define stub integrity_init_keyring() definition based on
  CONFIG_INTEGRITY_SIGNATURE, not CONFIG_INTEGRITY_ASYMMETRIC_KEYS.
  (reported-by Jim Davis)

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Acked-by: David Howells <dhowells@redhat.com>
2014-07-17 09:35:17 -04:00
Linus Torvalds
34ef7bd382 Revert "ima: define '_ima' as a builtin 'trusted' keyring"
This reverts commit 217091dd7a, which
caused the following build error:

  security/integrity/digsig.c:70:5: error: redefinition of ‘integrity_init_keyring’
  security/integrity/integrity.h:149:12: note: previous definition of ‘integrity_init_keyring’ w
  security/integrity/integrity.h:149:12: warning: ‘integrity_init_keyring’ defined but not used

reported by Krzysztof Kolasa. Mimi says:

 "I made the classic mistake of requesting this patch to be upstreamed
  at the last second, rather than waiting until the next open window.

  At this point, the best course would probably be to revert the two
  commits and fix them for the next open window"

Reported-by: Krzysztof Kolasa <kkolasa@winsoft.pl>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-23 16:36:35 -08:00
Mimi Zohar
217091dd7a ima: define '_ima' as a builtin 'trusted' keyring
Require all keys added to the IMA keyring be signed by an
existing trusted key on the system trusted keyring.

Changelog:
- define stub integrity_init_keyring() function (reported-by Fengguang Wu)
- differentiate between regular and trusted keyring names.
- replace printk with pr_info (D. Kasatkin)

Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
2013-10-31 20:20:48 -04:00
Dmitry Kasatkin
b1aaab22e2 ima: pass full xattr with the signature
For possibility to use xattr type for new signature formats,
pass full xattr to the signature verification function.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-10-25 17:16:59 -04:00
Dmitry Kasatkin
089bc8e95a ima: fix script messages
Fix checkpatch, lindent, etc, warnings/errors

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-10-25 13:17:19 -04:00
Dmitry Kasatkin
e0751257a6 ima: digital signature verification using asymmetric keys
Asymmetric keys were introduced in linux-3.7 to verify the signature on
signed kernel modules. The asymmetric keys infrastructure abstracts the
signature verification from the crypto details. This patch adds IMA/EVM
signature verification using asymmetric keys. Support for additional
signature verification methods can now be delegated to the asymmetric
key infrastructure.

Although the module signature header and the IMA/EVM signature header
could use the same format, to minimize the signature length and save
space in the extended attribute, this patch defines a new IMA/EVM
header format.  The main difference is that the key identifier is a
sha1[12 - 19] hash of the key modulus and exponent, similar to the
current implementation.  The only purpose of the key identifier is to
identify the corresponding key in the kernel keyring.  ima-evm-utils
was updated to support the new signature format.

While asymmetric signature verification functionality supports many
different hash algorithms, the hash used in this patch is calculated
during the IMA collection phase, based on the configured algorithm.
The default algorithm is sha1, but for backwards compatibility md5
is supported.  Due to this current limitation, signatures should be
generated using a sha1 hash algorithm.

Changes in this patch:
- Functionality has been moved to separate source file in order to get rid of
  in source #ifdefs.
- keyid is derived according to the RFC 3280. It does not require to assign
  IMA/EVM specific "description" when loading X509 certificate. Kernel
  asymmetric key subsystem automatically generate the description. Also
  loading a certificate does not require using of ima-evm-utils and can be
  done using keyctl only.
- keyid size is reduced to 32 bits to save xattr space.  Key search is done
  using partial match functionality of asymmetric_key_match().
- Kconfig option title was changed

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-02-06 21:22:18 -05:00
Dmitry Kasatkin
8607c50147 integrity: digital signature verification using multiple keyrings
Define separate keyrings for each of the different use cases - evm, ima,
and modules. Using different keyrings improves search performance, and also
allows "locking" specific keyring to prevent adding new keys.
This is useful for evm and module keyrings, when keys are usually only
added from initramfs.

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
2011-11-09 16:51:09 +02:00