doc: ReSTify IMA-templates.txt

Adjust IMA-templates.txt for ReST markup and add to the index for
security/, under the Kernel API Documentation.

Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/security/00-INDEX

@@ -22,5 +22,3 @@ keys.txt
 	- description of the kernel key retention service.
 tomoyo.txt
 	- documentation on the TOMOYO Linux Security Module.
-IMA-templates.txt
-	- documentation on the template management mechanism for IMA.

Documentation/security/IMA-templates.txt → Documentation/security/IMA-templates.rst

-                       IMA Template Management Mechanism
+=================================
+IMA Template Management Mechanism
+=================================
 
 
-==== INTRODUCTION ====
+Introduction
+============
 
-The original 'ima' template is fixed length, containing the filedata hash
+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
@@ -28,61 +31,64 @@ a new data type, developers define the field identifier and implement
 two functions, init() and show(), respectively to generate and display
 measurement entries. Defining a new template descriptor requires
 specifying the template format (a string of field identifiers separated
-by the '|' character) through the 'ima_template_fmt' kernel command line
+by the ``|`` character) through the ``ima_template_fmt`` kernel command line
 parameter. At boot time, IMA initializes the chosen template descriptor
 by translating the format into an array of template fields structures taken
 from the set of the supported ones.
 
-After the initialization step, IMA will call ima_alloc_init_template()
+After the initialization step, IMA will call ``ima_alloc_init_template()``
 (new function defined within the patches for the new template management
 mechanism) to generate a new measurement entry by using the template
 descriptor chosen through the kernel configuration or through the newly
-introduced 'ima_template' and 'ima_template_fmt' kernel command line parameters.
+introduced ``ima_template`` and ``ima_template_fmt`` kernel command line parameters.
 It is during this phase that the advantages of the new architecture are
 clearly shown: the latter function will not contain specific code to handle
-a given template but, instead, it simply calls the init() method of the template
+a given template but, instead, it simply calls the ``init()`` method of the template
 fields associated to the chosen template descriptor and store the result
 (pointer to allocated data and data length) in the measurement entry structure.
 
 The same mechanism is employed to display measurements entries.
-The functions ima[_ascii]_measurements_show() retrieve, for each entry,
+The functions ``ima[_ascii]_measurements_show()`` retrieve, for each entry,
 the template descriptor used to produce that entry and call the show()
 method for each item of the array of template fields structures.
 
 
 
-==== SUPPORTED TEMPLATE FIELDS AND DESCRIPTORS ====
+Supported Template Fields and Descriptors
+=========================================
 
 In the following, there is the list of supported template fields
-('<identifier>': description), that can be used to define new template
+``('<identifier>': description)``, that can be used to define new template
 descriptors by adding their identifier to the format string
 (support for more 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;
+   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);
+   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;
  - 'sig': the file signature.
 
 
 Below, there is the list of defined template descriptors:
- - "ima": its format is 'd|n';
- - "ima-ng" (default): its format is 'd-ng|n-ng';
- - "ima-sig": its format is 'd-ng|n-ng|sig'.
 
+ - "ima": its format is ``d|n``;
+ - "ima-ng" (default): its format is ``d-ng|n-ng``;
+ - "ima-sig": its format is ``d-ng|n-ng|sig``.
 
 
-==== USE ====
+
+Use
+===
 
 To specify the template descriptor to be used to generate measurement entries,
 currently the following methods are supported:
 
  - select a template descriptor among those supported in the kernel
-   configuration ('ima-ng' is the default choice);
+   configuration (``ima-ng`` is the default choice);
  - specify a template descriptor name from the kernel command line through
-   the 'ima_template=' parameter;
+   the ``ima_template=`` parameter;
  - register a new template descriptor with custom format through the kernel
-   command line parameter 'ima_template_fmt='.
+   command line parameter ``ima_template_fmt=``.

Documentation/security/index.rst

 ======================
-Security documentation
+Security Documentation
 ======================
 
 .. toctree::
+   :maxdepth: 1
 
+   IMA-templates
    tpm/index