This patch allows users to provide a custom template format through the
new kernel command line parameter 'ima_template_fmt'. If the supplied
format is not valid, IMA uses the default template descriptor.
Changelog:
- v3:
- added check for 'fields' and 'num_fields' in
template_desc_init_fields() (suggested by Mimi Zohar)
- v2:
- using template_desc_init_fields() to validate a format string
(Roberto Sassu)
- updated documentation by stating that only the chosen template
descriptor is initialized (Roberto Sassu)
- v1:
- simplified code of ima_template_fmt_setup()
(Roberto Sassu, suggested by Mimi Zohar)
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
The allocation of a field pointers array is moved at the end of
template_desc_init_fields() and done only if the value of the 'fields'
and 'num_fields' parameters is not NULL. For just validating a template
format string, retrieved template field pointers are placed in a temporary
array.
Changelog:
- v3:
- do not check in this patch if 'fields' and 'num_fields' are NULL
(suggested by Mimi Zohar)
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
This patch removes the allocation of a copy of 'template_fmt', needed for
iterating over all fields in the passed template format string. The removal
was possible by replacing strcspn(), which modifies the passed string,
with strchrnul(). The currently processed template field is copied in
a temporary variable.
The purpose of this change is use template_desc_init_fields() in two ways:
for just validating a template format string (the function should work
if called by a setup function, when memory cannot be allocated), and for
actually initializing a template descriptor. The implementation of this
feature will be complete with the next patch.
Changelog:
- v3:
- added 'goto out' in template_desc_init_fields() to free allocated
memory if a template field length is not valid (suggested by
Mimi Zohar)
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
With the introduction of the 'ima_template_fmt' kernel cmdline parameter,
a user can define a new template descriptor with custom format. However,
in this case, userspace tools will be unable to parse the measurements
list because the new template is unknown. For this reason, this patch
modifies the current IMA behavior to display in the list the template
format instead of the name (only if the length of the latter is zero)
so that a tool can extract needed information if it can handle listed
fields.
This patch also correctly displays the error log message in
ima_init_template() if the selected template cannot be initialized.
Changelog:
- v3:
- check the first byte of 'e->template_desc->name' instead of using
strlen() in ima_fs.c (suggested by Mimi Zohar)
- v2:
- print the template format in ima_init_template(), if the selected
template is custom (Roberto Sassu)
- v1:
- fixed patch description (Roberto Sassu, suggested by Mimi Zohar)
- set 'template_name' variable in ima_fs.c only once
(Roberto Sassu, suggested by Mimi Zohar)
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
This patch adds some error messages to inform users about the following
events: template descriptor not found, invalid template descriptor,
template field not found and template initialization failed.
Changelog:
- v2:
- display an error message if the format string contains too many
fields (Roberto Sassu)
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
IMA uses only one template. This patch initializes only required
template to avoid unnecessary memory allocations.
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Reviewed-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Add missing keywords to the function definition to cleanup
to discard initialization code.
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Reviewed-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Between checkpatch changes (eg. sizeof) and inconsistencies between
Lindent and checkpatch, unfixed checkpatch errors make it difficult
to see new errors. This patch fixes them. Some lines with over 80 chars
remained unchanged to improve code readability.
The "extern" keyword is removed from internal evm.h to make it consistent
with internal ima.h.
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
This patch stores the address of the 'template_fmt_copy' variable in a new
variable, called 'template_fmt_ptr', so that the latter is passed as an
argument of strsep() instead of the former. This modification is needed
in order to correctly free the memory area referenced by
'template_fmt_copy' (strsep() modifies the pointer of the passed string).
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Reported-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
This patch defines a new template called 'ima-sig', which includes
the file signature in the template data, in addition to the file's
digest and pathname.
A template is composed of a set of fields. Associated with each
field is an initialization and display function. This patch defines
a new template field called 'sig', the initialization function
ima_eventsig_init(), and the display function ima_show_template_sig().
This patch modifies the .field_init() function definition to include
the 'security.ima' extended attribute and length.
Changelog:
- remove unused code (Dmitry Kasatkin)
- avoid calling ima_write_template_field_data() unnecesarily (Roberto Sassu)
- rename DATA_FMT_SIG to DATA_FMT_HEX
- cleanup ima_eventsig_init() based on Roberto's comments
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
This patch allows users to specify from the kernel command line the
template descriptor, among those defined, that will be used to generate
and display measurement entries. If an user specifies a wrong template,
IMA reverts to the template descriptor set in the kernel configuration.
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
This patch adds a Kconfig option to select the default IMA
measurement list template. The 'ima' template limited the
filedata hash to 20 bytes and the pathname to 255 charaters.
The 'ima-ng' measurement list template permits larger hash
digests and longer pathnames.
Changelog:
- keep 'select CRYPTO_HASH_INFO' in 'config IMA' section (Kconfig)
(Roberto Sassu);
- removed trailing whitespaces (Roberto Sassu).
- Lindent fixes
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
This patch performs the switch to the new template mechanism by modifying
the functions ima_alloc_init_template(), ima_measurements_show() and
ima_ascii_measurements_show(). The old function ima_template_show() was
removed as it is no longer needed. Also, if the template descriptor used
to generate a measurement entry is not 'ima', the whole length of field
data stored for an entry is provided before the data itself through the
binary_runtime_measurement interface.
Changelog:
- unnecessary to use strncmp() (Mimi Zohar)
- create new variable 'field' in ima_alloc_init_template() (Roberto Sassu)
- use GFP_NOFS flag in ima_alloc_init_template() (Roberto Sassu)
- new variable 'num_fields' in ima_store_template() (Roberto Sassu,
proposed by Mimi Zohar)
- rename ima_calc_buffer_hash/template_hash() to ima_calc_field_array_hash(),
something more generic (Mimi, requested by Dmitry)
- sparse error fix - Fengguang Wu
- fix lindent warnings
- always include the field length in the template data length
- include the template field length variable size in the template data length
- include both the template field data and field length in the template digest
calculation. Simplifies verifying the template digest. (Mimi)
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
This patch adds support for the new template 'ima-ng', whose format
is defined as 'd-ng|n-ng'. These new field definitions remove the
size limitations of the original 'ima' template. Further, the 'd-ng'
field prefixes the inode digest with the hash algorithim, when
displaying the new larger digest sizes.
Change log:
- scripts/Lindent fixes - Mimi
- "always true comparison" - reported by Fengguang Wu, resolved Dmitry
- initialize hash_algo variable to HASH_ALGO__LAST
- always prefix digest with hash algorithm - Mimi
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
This patch defines a library containing two initial template fields,
inode digest (d) and file name (n), the 'ima' template descriptor,
whose format is 'd|n', and two helper functions,
ima_write_template_field_data() and ima_show_template_field_data().
Changelog:
- replace ima_eventname_init() parameter NULL checking with BUG_ON.
(suggested by Mimi)
- include "new template fields for inode digest (d) and file name (n)"
definitions to fix a compiler warning. - Mimi
- unnecessary to prefix static function names with 'ima_'. remove
prefix to resolve Lindent formatting changes. - Mimi
- abbreviated/removed inline comments - Mimi
- always send the template field length - Mimi
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
The original 'ima' template is fixed length, containing the filedata hash
and pathname. The filedata hash is limited to 20 bytes (md5/sha1). The
pathname is a null terminated string, limited to 255 characters. To
overcome these limitations and to add additional file metadata, it is
necessary to extend the current version of IMA by defining additional
templates.
The main reason to introduce this feature is that, each time a new
template is defined, the functions that generate and display the
measurement list would include the code for handling a new format and,
thus, would significantly grow over time.
This patch set solves this problem by separating the template management
from the remaining IMA code. The core of this solution is the definition
of two new data structures: a template descriptor, to determine which
information should be included in the measurement list, and a template
field, to generate and display data of a given type.
To define a new template field, developers define the field identifier
and implement two functions, init() and show(), respectively to generate
and display measurement entries. Initially, this patch set defines the
following template fields (support for additional data types will be
added later):
- 'd': the digest of the event (i.e. the digest of a measured file),
calculated with the SHA1 or MD5 hash algorithm;
- 'n': the name of the event (i.e. the file name), with size up to
255 bytes;
- 'd-ng': the digest of the event, calculated with an arbitrary hash
algorithm (field format: [<hash algo>:]digest, where the digest
prefix is shown only if the hash algorithm is not SHA1 or MD5);
- 'n-ng': the name of the event, without size limitations.
Defining a new template descriptor requires specifying the template format,
a string of field identifiers separated by the '|' character. This patch
set defines the following template descriptors:
- "ima": its format is 'd|n';
- "ima-ng" (default): its format is 'd-ng|n-ng'
Further details about the new template architecture can be found in
Documentation/security/IMA-templates.txt.
Changelog:
- don't defer calling ima_init_template() - Mimi
- don't define ima_lookup_template_desc() until used - Mimi
- squashed with documentation patch - Mimi
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Roberto Sassu