http://arctic.selinuxproject.org/w/?title=NB_MLS&feed=atom&action=history NB MLS - Revision history 2024-03-29T07:17:08Z Revision history for this page on the wiki MediaWiki 1.23.13 http://arctic.selinuxproject.org/w/?title=NB_MLS&diff=1792&oldid=prev RichardHaines at 13:43, 25 September 2015 2015-09-25T13:43:41Z <p></p> <table class='diff diff-contentalign-left'> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr style='vertical-align: top;'> <td colspan='2' style="background-color: white; color:black; text-align: center;">← Older revision</td> <td colspan='2' style="background-color: white; color:black; text-align: center;">Revision as of 13:43, 25 September 2015</td> </tr><tr><td colspan="2" class="diff-lineno">Line 2:</td> <td colspan="2" class="diff-lineno">Line 2:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>As stated in the [[NB_MAC | Mandatory Access Control (MAC)]] section as well as supporting Type Enforcement (TE), SELinux also supports MLS and MCS by adding an optional &lt;tt&gt;level&lt;/tt&gt; or &lt;tt&gt;range&lt;/tt&gt; entry to the security context. This section gives a brief introduction to MLS and MCS.</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>As stated in the [[NB_MAC | Mandatory Access Control (MAC)]] section as well as supporting Type Enforcement (TE), SELinux also supports MLS and MCS by adding an optional &lt;tt&gt;level&lt;/tt&gt; or &lt;tt&gt;range&lt;/tt&gt; entry to the security context. This section gives a brief introduction to MLS and MCS.</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The [http://<del class="diffchange diffchange-inline">taiga.</del>selinuxproject.org/~rhaines/NB4-diagrams/8-security-levels.png Security Levels and Data Flows] diagram shows a simple view where security levels represent the classification of files within a file server. The security levels are strictly hierarchical and conform to the [http://en.wikipedia.org/wiki/Bell-LaPadula_model Bell-La Padula model] (BLP) in that (in the case of SELinux) a process (running at the &quot;Confidential&quot; level) can read / write at their current level but only read down levels or write up levels (the assumption here is that the process is authorised).</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The [http://selinuxproject.org/~rhaines/NB4-diagrams/8-security-levels.png Security Levels and Data Flows] diagram shows a simple view where security levels represent the classification of files within a file server. The security levels are strictly hierarchical and conform to the [http://en.wikipedia.org/wiki/Bell-LaPadula_model Bell-La Padula model] (BLP) in that (in the case of SELinux) a process (running at the &quot;Confidential&quot; level) can read / write at their current level but only read down levels or write up levels (the assumption here is that the process is authorised).</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>This ensures confidentiality as the process can copy a file up to the secret level, but can never re-read that content unless the process &quot;steps up to that level&quot;, also the process cannot write files to the lower levels as confidential information would then drift downwards.</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>This ensures confidentiality as the process can copy a file up to the secret level, but can never re-read that content unless the process &quot;steps up to that level&quot;, also the process cannot write files to the lower levels as confidential information would then drift downwards.</div></td></tr> <tr><td colspan="2" class="diff-lineno">Line 124:</td> <td colspan="2" class="diff-lineno">Line 124:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>: '''Security Level 1 is incomparable to Security Level 2''' - If the categories of Security Level 1 and Security Level 2 cannot be compared (i.e. neither Security Level dominates the other).</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>: '''Security Level 1 is incomparable to Security Level 2''' - If the categories of Security Level 1 and Security Level 2 cannot be compared (i.e. neither Security Level dominates the other).</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>To illustrate the usage of these rules, the [http://<del class="diffchange diffchange-inline">taiga.</del>selinuxproject.org/~rhaines/diagrams/t2-MLS-Security-Levels.png MLS Security Levels example] table lists the security level attributes in a table to show example files (or documents) that have been allocated labels such as &lt;tt&gt;s3:c0&lt;/tt&gt;. The process that accesses these files (e.g. an editor) is running with a range of &lt;tt&gt;s0 - s3:c1.c5&lt;/tt&gt; and has access to the files highlighted within the grey box area.</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>To illustrate the usage of these rules, the [http://selinuxproject.org/~rhaines/diagrams/t2-MLS-Security-Levels.png MLS Security Levels example] table lists the security level attributes in a table to show example files (or documents) that have been allocated labels such as &lt;tt&gt;s3:c0&lt;/tt&gt;. The process that accesses these files (e.g. an editor) is running with a range of &lt;tt&gt;s0 - s3:c1.c5&lt;/tt&gt; and has access to the files highlighted within the grey box area.</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>As the MLS &lt;tt&gt;dominance&lt;/tt&gt; Statement is used to enforce the sensitivity hierarchy, the security levels now follow that sequence (lowest = &lt;tt&gt;s0&lt;/tt&gt; to highest = &lt;tt&gt;s3&lt;/tt&gt;) with the categories being unordered lists of &quot;compartments&quot;. To allow the process access to files within its scope and within the dominance rules, the process will be constrained by using the &lt;tt&gt;mlsconstrain&lt;/tt&gt; statement as illustrated in the&#160; [http://<del class="diffchange diffchange-inline">taiga.</del>selinuxproject.org/~rhaines/diagrams/9-mls-constrain.png MLS constrain] diagram. &#160;</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>As the MLS &lt;tt&gt;dominance&lt;/tt&gt; Statement is used to enforce the sensitivity hierarchy, the security levels now follow that sequence (lowest = &lt;tt&gt;s0&lt;/tt&gt; to highest = &lt;tt&gt;s3&lt;/tt&gt;) with the categories being unordered lists of &quot;compartments&quot;. To allow the process access to files within its scope and within the dominance rules, the process will be constrained by using the &lt;tt&gt;mlsconstrain&lt;/tt&gt; statement as illustrated in the&#160; [http://selinuxproject.org/~rhaines/diagrams/9-mls-constrain.png MLS constrain] diagram. &#160;</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>So using the [http://<del class="diffchange diffchange-inline">taiga.</del>selinuxproject.org/~rhaines/NB4-diagrams/9-mls-constrain.png MLS constrain] diagram:</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>So using the [http://selinuxproject.org/~rhaines/NB4-diagrams/9-mls-constrain.png MLS constrain] diagram:</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div># To allow write-up, the source level (&lt;tt&gt;l1&lt;/tt&gt;) must be '''dominated by''' the target level (&lt;tt&gt;l2&lt;/tt&gt;):</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div># To allow write-up, the source level (&lt;tt&gt;l1&lt;/tt&gt;) must be '''dominated by''' the target level (&lt;tt&gt;l2&lt;/tt&gt;):</div></td></tr> </table> RichardHaines http://arctic.selinuxproject.org/w/?title=NB_MLS&diff=1744&oldid=prev RichardHaines at 15:18, 13 December 2014 2014-12-13T15:18:28Z <p></p> <table class='diff diff-contentalign-left'> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr style='vertical-align: top;'> <td colspan='2' style="background-color: white; color:black; text-align: center;">← Older revision</td> <td colspan='2' style="background-color: white; color:black; text-align: center;">Revision as of 15:18, 13 December 2014</td> </tr><tr><td colspan="2" class="diff-lineno">Line 23:</td> <td colspan="2" class="diff-lineno">Line 23:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>The table also adds terminology in general use as other terms can be used that have the same meanings. &#160;</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>The table also adds terminology in general use as other terms can be used that have the same meanings. &#160;</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>&#160;</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">''Table 1: Level, Label, Category or Compartment - this table shows the meanings depending on the context being discussed.''</ins></div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>{|border=&quot;1&quot;</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>{|border=&quot;1&quot;</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>|&lt;center&gt;'''Security Level (or Level)'''&lt;/center&gt;</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>|&lt;center&gt;'''Security Level (or Level)'''&lt;/center&gt;</div></td></tr> <tr><td colspan="2" class="diff-lineno">Line 76:</td> <td colspan="2" class="diff-lineno">Line 76:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>|}</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>|}</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">''Table 1: Level, Label, Category or Compartment - this table shows the meanings depending on the context being discussed.''</del></div></td><td colspan="2">&#160;</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>The format used in the policy language statements is fully described in the [[MLSStatements | MLS Statements]] section, however a brief overview follows.</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>The format used in the policy language statements is fully described in the [[MLSStatements | MLS Statements]] section, however a brief overview follows.</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;"></del></div></td><td colspan="2">&#160;</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>=== MLS / MCS Range Format ===</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>=== MLS / MCS Range Format ===</div></td></tr> <tr><td colspan="2" class="diff-lineno">Line 113:</td> <td colspan="2" class="diff-lineno">Line 111:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>=== Translating Levels ===</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>=== Translating Levels ===</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>When writing policy for MLS / MCS security level components it is usual to use an abbreviated form such as s0, s1 etc. to represent sensitivities and c0, c1 etc. to represent categories. This is done simply to conserve space as they are held on files as extended attributes and also in memory. So that these labels can be represented in human readable form, a translation service is provided via the [#<del class="diffchange diffchange-inline">_./</del>setrans.<del class="diffchange diffchange-inline">conf_File </del>setrans.conf] configuration file that is used by the '''mcstransd'''(8) daemon. For example s0 = Unclassified, s15 = Top Secret and c0 = Finance, c100 = Spy Stories. The '''semanage'''(8) command can be used to set up this translation and is shown in the [[PolicyConfigurationFiles#setrans.conf_File | setrans.conf]] configuration file section.</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>When writing policy for MLS / MCS security level components it is usual to use an abbreviated form such as s0, s1 etc. to represent sensitivities and c0, c1 etc. to represent categories. This is done simply to conserve space as they are held on files as extended attributes and also in memory. So that these labels can be represented in human readable form, a translation service is provided via the [<ins class="diffchange diffchange-inline">[PolicyConfigurationFiles</ins>#setrans.<ins class="diffchange diffchange-inline">conf File | </ins>setrans.conf<ins class="diffchange diffchange-inline">]</ins>] configuration file that is used by the '''mcstransd'''(8) daemon. For example s0 = Unclassified, s15 = Top Secret and c0 = Finance, c100 = Spy Stories. The '''semanage'''(8) command can be used to set up this translation and is shown in the [[PolicyConfigurationFiles#setrans.conf_File | setrans.conf]] configuration file section.</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>== Managing Security Levels via Dominance Rules ==</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>== Managing Security Levels via Dominance Rules ==</div></td></tr> </table> RichardHaines http://arctic.selinuxproject.org/w/?title=NB_MLS&diff=1700&oldid=prev RichardHaines at 11:56, 7 December 2014 2014-12-07T11:56:43Z <p></p> <table class='diff diff-contentalign-left'> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr style='vertical-align: top;'> <td colspan='2' style="background-color: white; color:black; text-align: center;">← Older revision</td> <td colspan='2' style="background-color: white; color:black; text-align: center;">Revision as of 11:56, 7 December 2014</td> </tr><tr><td colspan="2" class="diff-lineno">Line 160:</td> <td colspan="2" class="diff-lineno">Line 160:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>An interesting point:</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>An interesting point:</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>* Both Red Hat Linux 5.1 and Microsoft Server 2003 (with XP) have both been certified to EAL4+ , however while the evaluation levels may be the same the Protection Profiles that they were evaluated under were: Microsoft CAPP only, Red Hat CAPP and LSPP. Therefore always look at the protection profiles as they define what was actually evaluated.</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>* Both Red Hat Linux 5.1 and Microsoft Server 2003 (with XP) have both been certified to EAL4+ , however while the evaluation levels may be the same the Protection Profiles that they were evaluated under were: Microsoft CAPP only, Red Hat CAPP and LSPP. Therefore always look at the protection profiles as they define what was actually evaluated.</div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"></ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"></ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">{| style=&quot;width: 100%;&quot; border=&quot;0&quot;</ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">|-</ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">| [[NB_Domain_and_Object_Transitions | '''Previous''']]</ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">| &lt;center&gt;[[NewUsers | '''Home''']]&lt;/center&gt;</ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">| &lt;center&gt;[[NB_PolicyType | '''Next''']]&lt;/center&gt;</ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">|}</ins></div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> </table> RichardHaines http://arctic.selinuxproject.org/w/?title=NB_MLS&diff=1691&oldid=prev RichardHaines at 14:36, 5 December 2014 2014-12-05T14:36:26Z <p></p> <table class='diff diff-contentalign-left'> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr style='vertical-align: top;'> <td colspan='2' style="background-color: white; color:black; text-align: center;">← Older revision</td> <td colspan='2' style="background-color: white; color:black; text-align: center;">Revision as of 14:36, 5 December 2014</td> </tr><tr><td colspan="2" class="diff-lineno">Line 2:</td> <td colspan="2" class="diff-lineno">Line 2:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>As stated in the [[NB_MAC | Mandatory Access Control (MAC)]] section as well as supporting Type Enforcement (TE), SELinux also supports MLS and MCS by adding an optional &lt;tt&gt;level&lt;/tt&gt; or &lt;tt&gt;range&lt;/tt&gt; entry to the security context. This section gives a brief introduction to MLS and MCS.</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>As stated in the [[NB_MAC | Mandatory Access Control (MAC)]] section as well as supporting Type Enforcement (TE), SELinux also supports MLS and MCS by adding an optional &lt;tt&gt;level&lt;/tt&gt; or &lt;tt&gt;range&lt;/tt&gt; entry to the security context. This section gives a brief introduction to MLS and MCS.</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The [http://taiga.selinuxproject.org/~rhaines/diagrams/8-security-levels.png Security Levels and Data Flows] diagram shows a simple view where security levels represent the classification of files within a file server. The security levels are strictly hierarchical and conform to the [http://en.wikipedia.org/wiki/Bell-LaPadula_model Bell-La Padula model] (BLP) in that (in the case of SELinux) a process (running at the &quot;Confidential&quot; level) can read / write at their current level but only read down levels or write up levels (the assumption here is that the process is authorised).</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The [http://taiga.selinuxproject.org/~rhaines/<ins class="diffchange diffchange-inline">NB4-</ins>diagrams/8-security-levels.png Security Levels and Data Flows] diagram shows a simple view where security levels represent the classification of files within a file server. The security levels are strictly hierarchical and conform to the [http://en.wikipedia.org/wiki/Bell-LaPadula_model Bell-La Padula model] (BLP) in that (in the case of SELinux) a process (running at the &quot;Confidential&quot; level) can read / write at their current level but only read down levels or write up levels (the assumption here is that the process is authorised).</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>This ensures confidentiality as the process can copy a file up to the secret level, but can never re-read that content unless the process &quot;steps up to that level&quot;, also the process cannot write files to the lower levels as confidential information would then drift downwards.</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>This ensures confidentiality as the process can copy a file up to the secret level, but can never re-read that content unless the process &quot;steps up to that level&quot;, also the process cannot write files to the lower levels as confidential information would then drift downwards.</div></td></tr> <tr><td colspan="2" class="diff-lineno">Line 33:</td> <td colspan="2" class="diff-lineno">Line 33:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>| &lt;tt&gt;&lt;center&gt;sensitivity [: category, ... ]&lt;/center&gt;&lt;/tt&gt;</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>| &lt;tt&gt;&lt;center&gt;sensitivity [: category, ... ]&lt;/center&gt;&lt;/tt&gt;</div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"></ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"> &lt;center&gt;also known as:&lt;/center&gt;</ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"></ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">&lt;center&gt;'''Sensitivity Label'''&lt;/center&gt;</ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"></ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">&lt;center&gt;Consisting of a classification and compartment.&lt;/center&gt;</ins></div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td></tr> <tr><td colspan="2" class="diff-lineno">Line 80:</td> <td colspan="2" class="diff-lineno">Line 86:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>&lt;pre&gt;</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>&lt;pre&gt;</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>user:role:type:sensitivity[:category,...]&#160; -&#160; sensitivity [:category,...]</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>user:role:type:sensitivity[:category,...]&#160; -&#160; sensitivity [:category,...]</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>---------------<del class="diffchange diffchange-inline">x</del>------------------------<del class="diffchange diffchange-inline">x</del>-----<del class="diffchange diffchange-inline">x</del>-------------------------<del class="diffchange diffchange-inline">x</del></div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>---------------<ins class="diffchange diffchange-inline">▼</ins>------------------------<ins class="diffchange diffchange-inline">▼</ins>-----<ins class="diffchange diffchange-inline">▼</ins>-------------------------<ins class="diffchange diffchange-inline">▼</ins></div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>&#160;&#160; &#160; &#160; &#160; &#160; &#160; &#160; |&#160; &#160; &#160; &#160; level&#160; &#160; &#160; &#160; &#160; |&#160; -&#160; |&#160; &#160; &#160; &#160; level&#160; &#160; &#160; &#160; &#160; &#160; |</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>&#160;&#160; &#160; &#160; &#160; &#160; &#160; &#160; |&#160; &#160; &#160; &#160; level&#160; &#160; &#160; &#160; &#160; |&#160; -&#160; |&#160; &#160; &#160; &#160; level&#160; &#160; &#160; &#160; &#160; &#160; |</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>&#160;&#160; &#160; &#160; &#160; &#160; &#160; &#160; |&#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; |</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>&#160;&#160; &#160; &#160; &#160; &#160; &#160; &#160; |&#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; &#160; |</div></td></tr> <tr><td colspan="2" class="diff-lineno">Line 107:</td> <td colspan="2" class="diff-lineno">Line 113:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>=== Translating Levels ===</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>=== Translating Levels ===</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>When writing policy for MLS / MCS security level components it is usual to use an abbreviated form such as <del class="diffchange diffchange-inline">&lt;tt&gt;</del>s0, s1<del class="diffchange diffchange-inline">&lt;/tt&gt; </del>etc. to represent sensitivities and <del class="diffchange diffchange-inline">&lt;tt&gt;</del>c0, c1<del class="diffchange diffchange-inline">&lt;/tt&gt; </del>etc. to represent categories. This is done simply to conserve space as they are held on files as extended attributes and also in memory. So that these labels can be represented in human readable form a translation service is provided via the <del class="diffchange diffchange-inline">&lt;tt&gt;</del>setrans.conf<del class="diffchange diffchange-inline">&lt;/tt&gt; </del>configuration file that <del class="diffchange diffchange-inline">uses </del>the <del class="diffchange diffchange-inline">&lt;tt&gt;</del>mcstransd<del class="diffchange diffchange-inline">&lt;/tt&gt; </del>daemon. For example <del class="diffchange diffchange-inline">&lt;tt&gt;</del>s0 = Unclassified<del class="diffchange diffchange-inline">&lt;/tt&gt;</del>, <del class="diffchange diffchange-inline">&lt;tt&gt;</del>s15 = <del class="diffchange diffchange-inline">TopSecret&lt;/tt&gt; </del>and <del class="diffchange diffchange-inline">&lt;tt&gt;</del>c0 = Finance<del class="diffchange diffchange-inline">&lt;/tt&gt;</del>, <del class="diffchange diffchange-inline">&lt;tt&gt;</del>c100 = <del class="diffchange diffchange-inline">SpyStories&lt;/tt&gt; (unfortunately the translation does not support spaces in words)</del>. The <del class="diffchange diffchange-inline">&lt;tt&gt;</del>semanage(8)<del class="diffchange diffchange-inline">&lt;/tt&gt; </del>command can be used to set up this translation and is shown in the [[<del class="diffchange diffchange-inline">GlobalConfigurationFiles </del>| <del class="diffchange diffchange-inline">Global Configuration Files</del>]] section.</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>When writing policy for MLS / MCS security level components it is usual to use an abbreviated form such as s0, s1 etc. to represent sensitivities and c0, c1 etc. to represent categories. This is done simply to conserve space as they are held on files as extended attributes and also in memory. So that these labels can be represented in human readable form<ins class="diffchange diffchange-inline">, </ins>a translation service is provided via the <ins class="diffchange diffchange-inline">[#_./setrans.conf_File </ins>setrans.conf<ins class="diffchange diffchange-inline">] </ins>configuration file that <ins class="diffchange diffchange-inline">is used by </ins>the <ins class="diffchange diffchange-inline">'''</ins>mcstransd<ins class="diffchange diffchange-inline">'''(8) </ins>daemon. For example s0 = Unclassified, s15 = <ins class="diffchange diffchange-inline">Top Secret </ins>and c0 = Finance, c100 = <ins class="diffchange diffchange-inline">Spy Stories</ins>. The <ins class="diffchange diffchange-inline">'''</ins>semanage<ins class="diffchange diffchange-inline">'''</ins>(8) command can be used to set up this translation and is shown in the [[<ins class="diffchange diffchange-inline">PolicyConfigurationFiles#setrans.conf_File </ins>| <ins class="diffchange diffchange-inline">setrans.conf</ins>]] <ins class="diffchange diffchange-inline">configuration file </ins>section.</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>== Managing Security Levels via Dominance Rules ==</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>== Managing Security Levels via Dominance Rules ==</div></td></tr> <tr><td colspan="2" class="diff-lineno">Line 124:</td> <td colspan="2" class="diff-lineno">Line 130:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>As the MLS &lt;tt&gt;dominance&lt;/tt&gt; Statement is used to enforce the sensitivity hierarchy, the security levels now follow that sequence (lowest = &lt;tt&gt;s0&lt;/tt&gt; to highest = &lt;tt&gt;s3&lt;/tt&gt;) with the categories being unordered lists of &quot;compartments&quot;. To allow the process access to files within its scope and within the dominance rules, the process will be constrained by using the &lt;tt&gt;mlsconstrain&lt;/tt&gt; statement as illustrated in the&#160; [http://taiga.selinuxproject.org/~rhaines/diagrams/9-mls-constrain.png MLS constrain] diagram. &#160;</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>As the MLS &lt;tt&gt;dominance&lt;/tt&gt; Statement is used to enforce the sensitivity hierarchy, the security levels now follow that sequence (lowest = &lt;tt&gt;s0&lt;/tt&gt; to highest = &lt;tt&gt;s3&lt;/tt&gt;) with the categories being unordered lists of &quot;compartments&quot;. To allow the process access to files within its scope and within the dominance rules, the process will be constrained by using the &lt;tt&gt;mlsconstrain&lt;/tt&gt; statement as illustrated in the&#160; [http://taiga.selinuxproject.org/~rhaines/diagrams/9-mls-constrain.png MLS constrain] diagram. &#160;</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>So using the [http://taiga.selinuxproject.org/~rhaines/diagrams/9-mls-constrain.png MLS constrain] diagram:</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>So using the [http://taiga.selinuxproject.org/~rhaines/<ins class="diffchange diffchange-inline">NB4-</ins>diagrams/9-mls-constrain.png MLS constrain] diagram:</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div># To allow write-up, the source level (&lt;tt&gt;l1&lt;/tt&gt;) must be '''dominated by''' the target level (&lt;tt&gt;l2&lt;/tt&gt;):</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div># To allow write-up, the source level (&lt;tt&gt;l1&lt;/tt&gt;) must be '''dominated by''' the target level (&lt;tt&gt;l2&lt;/tt&gt;):</div></td></tr> <tr><td colspan="2" class="diff-lineno">Line 143:</td> <td colspan="2" class="diff-lineno">Line 149:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>Networking for MLS is supported via the NetLabel CIPSO (commercial IP security option) service as discussed in the [[NB_Networking | SELinux Networking Support]] section.</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>Networking for MLS is supported via the NetLabel CIPSO (commercial IP security option) service as discussed in the [[NB_Networking | SELinux Networking Support]] section.</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>PostgreSQL supports labeling for MLS database services as discussed in the <del class="diffchange diffchange-inline">&quot;</del>[<del class="diffchange diffchange-inline">http://wiki</del>.<del class="diffchange diffchange-inline">postgresql.org/wiki/SEPostgreSQL_Development Security</del>-<del class="diffchange diffchange-inline">Enhanced </del>PostgreSQL <del class="diffchange diffchange-inline">Security Wiki</del>]<del class="diffchange diffchange-inline">&quot;</del>.</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>PostgreSQL supports labeling for MLS database services as discussed in the [<ins class="diffchange diffchange-inline">[NB_SQL_9</ins>.<ins class="diffchange diffchange-inline">3 | SE</ins>-PostgreSQL <ins class="diffchange diffchange-inline">Support]</ins>] <ins class="diffchange diffchange-inline">section</ins>.</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>== Common Criteria Certification ==</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>== Common Criteria Certification ==</div></td></tr> </table> RichardHaines http://arctic.selinuxproject.org/w/?title=NB_MLS&diff=1028&oldid=prev Jaxelson at 20:47, 13 September 2010 2010-09-13T20:47:12Z <p></p> <table class='diff diff-contentalign-left'> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr style='vertical-align: top;'> <td colspan='2' style="background-color: white; color:black; text-align: center;">← Older revision</td> <td colspan='2' style="background-color: white; color:black; text-align: center;">Revision as of 20:47, 13 September 2010</td> </tr><tr><td colspan="2" class="diff-lineno">Line 158:</td> <td colspan="2" class="diff-lineno">Line 158:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>----</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>----</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>&lt;references/&gt;</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>&lt;references/&gt;</div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"></ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">[[Category:Notebook]]</ins></div></td></tr> </table> Jaxelson http://arctic.selinuxproject.org/w/?title=NB_MLS&diff=946&oldid=prev RichardHaines: /* Managing Security Levels via Dominance Rules */ 2010-05-16T14:36:17Z <p>‎<span dir="auto"><span class="autocomment">Managing Security Levels via Dominance Rules</span></span></p> <table class='diff diff-contentalign-left'> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr style='vertical-align: top;'> <td colspan='2' style="background-color: white; color:black; text-align: center;">← Older revision</td> <td colspan='2' style="background-color: white; color:black; text-align: center;">Revision as of 14:36, 16 May 2010</td> </tr><tr><td colspan="2" class="diff-lineno">Line 112:</td> <td colspan="2" class="diff-lineno">Line 112:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>As stated earlier, allowing a process access to an object is managed by &quot;dominance&quot; rules applied to the security levels. These rules are as follows:</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>As stated earlier, allowing a process access to an object is managed by &quot;dominance&quot; rules applied to the security levels. These rules are as follows:</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">#</del>: '''Security Level 1 dominates Security Level 2''' - If the sensitivity of Security Level 1 is equal to or higher than the sensitivity of Security Level 2 and the categories of Security Level 1 are the same or a superset of the categories of Security Level 2.</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>: '''Security Level 1 dominates Security Level 2''' - If the sensitivity of Security Level 1 is equal to or higher than the sensitivity of Security Level 2 and the categories of Security Level 1 are the same or a superset of the categories of Security Level 2.</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">#</del>: '''Security Level 1 is dominated by Security Level 2''' - If the sensitivity of Security Level 1 is equal to or lower than the sensitivity of Security Level 2 and the categories of Security Level 1 are a subset of the categories of Security Level 2.</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>: '''Security Level 1 is dominated by Security Level 2''' - If the sensitivity of Security Level 1 is equal to or lower than the sensitivity of Security Level 2 and the categories of Security Level 1 are a subset of the categories of Security Level 2.</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">#</del>: '''Security Level 1 equals Security Level 2''' - If the sensitivity of Security Level 1 is equal to Security Level 2 and the categories of Security Level 1 and Security Level 2 are the same set (sometimes expressed as: both Security Levels dominate each other).</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>: '''Security Level 1 equals Security Level 2''' - If the sensitivity of Security Level 1 is equal to Security Level 2 and the categories of Security Level 1 and Security Level 2 are the same set (sometimes expressed as: both Security Levels dominate each other).</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">#</del>: '''Security Level 1 is incomparable to Security Level 2''' - If the categories of Security Level 1 and Security Level 2 cannot be compared (i.e. neither Security Level dominates the other).</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>: '''Security Level 1 is incomparable to Security Level 2''' - If the categories of Security Level 1 and Security Level 2 cannot be compared (i.e. neither Security Level dominates the other).</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>To illustrate the usage of these rules, the [http://taiga.selinuxproject.org/~rhaines/diagrams/t2-MLS-Security-Levels.png MLS Security Levels example] table lists the security level attributes in a table to show example files (or documents) that have been allocated labels such as &lt;tt&gt;s3:c0&lt;/tt&gt;. The process that accesses these files (e.g. an editor) is running with a range of &lt;tt&gt;s0 - s3:c1.c5&lt;/tt&gt; and has access to the files highlighted within the grey box area.</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>To illustrate the usage of these rules, the [http://taiga.selinuxproject.org/~rhaines/diagrams/t2-MLS-Security-Levels.png MLS Security Levels example] table lists the security level attributes in a table to show example files (or documents) that have been allocated labels such as &lt;tt&gt;s3:c0&lt;/tt&gt;. The process that accesses these files (e.g. an editor) is running with a range of &lt;tt&gt;s0 - s3:c1.c5&lt;/tt&gt; and has access to the files highlighted within the grey box area.</div></td></tr> <tr><td colspan="2" class="diff-lineno">Line 127:</td> <td colspan="2" class="diff-lineno">Line 127:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div># To allow write-up, the source level (&lt;tt&gt;l1&lt;/tt&gt;) must be '''dominated by''' the target level (&lt;tt&gt;l2&lt;/tt&gt;):</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div># To allow write-up, the source level (&lt;tt&gt;l1&lt;/tt&gt;) must be '''dominated by''' the target level (&lt;tt&gt;l2&lt;/tt&gt;):</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">#</del>: Source level = &lt;tt&gt;s0:c3&lt;/tt&gt; or &lt;tt&gt;s1:c1&lt;/tt&gt;</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>: Source level = &lt;tt&gt;s0:c3&lt;/tt&gt; or &lt;tt&gt;s1:c1&lt;/tt&gt;</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">#</del>: Target level = &lt;tt&gt;s2:c1.c4&lt;/tt&gt;</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>: Target level = &lt;tt&gt;s2:c1.c4&lt;/tt&gt;</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>As can be seen, either of the source levels are '''dominated by''' the target level.</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>As can be seen, either of the source levels are '''dominated by''' the target level.</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div># To allow read-down, the source level (&lt;tt&gt;l1&lt;/tt&gt;) must '''dominate''' the target level (&lt;tt&gt;l2&lt;/tt&gt;):</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div># To allow read-down, the source level (&lt;tt&gt;l1&lt;/tt&gt;) must '''dominate''' the target level (&lt;tt&gt;l2&lt;/tt&gt;):</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">#</del>: Source level = &lt;tt&gt;s2:c1.c4&lt;/tt&gt;</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>: Source level = &lt;tt&gt;s2:c1.c4&lt;/tt&gt;</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">#</del>: Target level = &lt;tt&gt;s0:c3&lt;/tt&gt;</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>: Target level = &lt;tt&gt;s0:c3&lt;/tt&gt;</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>As can be seen, the source level does '''dominate''' the target level.</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>As can be seen, the source level does '''dominate''' the target level.</div></td></tr> </table> RichardHaines http://arctic.selinuxproject.org/w/?title=NB_MLS&diff=945&oldid=prev RichardHaines: /* Security Levels */ 2010-05-16T14:34:22Z <p>‎<span dir="auto"><span class="autocomment">Security Levels</span></span></p> <table class='diff diff-contentalign-left'> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr style='vertical-align: top;'> <td colspan='2' style="background-color: white; color:black; text-align: center;">← Older revision</td> <td colspan='2' style="background-color: white; color:black; text-align: center;">Revision as of 14:34, 16 May 2010</td> </tr><tr><td colspan="2" class="diff-lineno">Line 19:</td> <td colspan="2" class="diff-lineno">Line 19:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>== Security Levels ==</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>== Security Levels ==</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Table 1 shows the components that make up a security level and how two security levels form a range for the fourth and optional &lt;nowiki&gt;[:level]&lt;/nowiki&gt; of the [[NB_SC | security context]] within an MLS / MCS environment.</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Table 1 shows the components that make up a security level and how two security levels form a range for the fourth and optional <ins class="diffchange diffchange-inline">&lt;tt&gt;</ins>&lt;nowiki&gt;[:level]&lt;/nowiki<ins class="diffchange diffchange-inline">&gt;&lt;/tt</ins>&gt; of the [[NB_SC | security context]] within an MLS / MCS environment.</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>The table also adds terminology in general use as other terms can be used that have the same meanings. &#160;</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>The table also adds terminology in general use as other terms can be used that have the same meanings. &#160;</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>{| border=&quot;1&quot;</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>{|border=&quot;1&quot;</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>| &lt;center&gt;'''Security Level (or Level)'''&lt;/center&gt;</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>|&lt;center&gt;'''Security Level (or Level)'''&lt;/center&gt;</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>&lt;center&gt;Consisting of a sensitivity and zero or more category entries:&lt;/center&gt;</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>&lt;center&gt;Consisting of a sensitivity and zero or more category entries:&lt;/center&gt;</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">| colspan=&quot;2&quot; | Note that SELinux uses level, sensitivity and category in the language statements (see the [[MLSStatements | MLS Language Statements]] section), however when discussing these the following terms can also be used: labels, classifications, and compartments.</del></div></td><td colspan="2">&#160;</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>|<del class="diffchange diffchange-inline">-</del></div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">!colspan=&quot;2&quot; rowspan=&quot;2&quot;</ins>| <ins class="diffchange diffchange-inline">Note that SELinux uses level, </ins>sensitivity <ins class="diffchange diffchange-inline">and </ins>category <ins class="diffchange diffchange-inline">in the language statements</ins>, <ins class="diffchange diffchange-inline">however when discussing these the following terms can also be used: labels, classifications, and compartments</ins>.</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">| </del>sensitivity <del class="diffchange diffchange-inline">[: </del>category, .<del class="diffchange diffchange-inline">.. ]</del></div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div></div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>| &lt;<del class="diffchange diffchange-inline">center</del>&gt;<del class="diffchange diffchange-inline">also known as:</del>&lt;<del class="diffchange diffchange-inline">/</del>center&gt;</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>| &lt;<ins class="diffchange diffchange-inline">tt</ins>&gt;&lt;center&gt;<ins class="diffchange diffchange-inline">sensitivity [: category, ... ]</ins>&lt;/center&gt;&lt;/<ins class="diffchange diffchange-inline">tt</ins>&gt;</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>&#160;</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div></div></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">&lt;center&gt;'''Sensitivity Label'''</del>&lt;/center&gt;</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div></div></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>&#160;</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div></div></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; 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vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">| </del>colspan=&quot;3&quot; | &lt;center&gt;<del class="diffchange diffchange-inline">'''&lt;- </del>Range <del class="diffchange diffchange-inline">-&gt; '''</del>&lt;/center&gt;</div></td><td class='diff-marker'>+</td><td style="color:black; 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vertical-align: top; white-space: pre-wrap;"><div>|-</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>| &lt;center&gt;<del class="diffchange diffchange-inline">'''</del>Low<del class="diffchange diffchange-inline">'''</del>&lt;/center&gt;</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>|&lt;center&gt;Low&lt;/center&gt;</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>| &#160;</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>| &#160;</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>| &lt;center&gt;<del class="diffchange diffchange-inline">'''</del>High<del class="diffchange diffchange-inline">'''</del>&lt;/center&gt;</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>|&lt;center&gt;High&lt;/center&gt;</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>| sensitivity [: category, ... ]</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>| <ins class="diffchange diffchange-inline">&lt;tt&gt;&lt;center&gt;</ins>sensitivity [: category, ... ]<ins class="diffchange diffchange-inline">&lt;/center&gt;&lt;/tt&gt;</ins></div></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>| &lt;center&gt;<del class="diffchange diffchange-inline">'''</del>-<del class="diffchange diffchange-inline">'''</del>&lt;/center&gt;</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>| &lt;center&gt;-&lt;/center&gt;</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>| &lt;<del class="diffchange diffchange-inline">div align=&quot;right&quot;</del>&gt;sensitivity [: category, ... ]&lt;/<del class="diffchange diffchange-inline">div</del>&gt;</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>| &lt;<ins class="diffchange diffchange-inline">tt&gt;&lt;center</ins>&gt;sensitivity [: category, ... ]&lt;/<ins class="diffchange diffchange-inline">center&gt;&lt;/tt</ins>&gt;</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>| &lt;center&gt;For a process or subject this is the current level or sensitivity&lt;/center&gt;</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>|&lt;center&gt;For a process or subject this is the current level or sensitivity&lt;/center&gt;</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>| &#160;</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>| &#160;</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>| &lt;center&gt;For a process or subject this is the Clearance&lt;/center&gt;</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>|&lt;center&gt;For a process or subject this is the Clearance&lt;/center&gt;</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; 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font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>| &lt;center&gt;For an object this is the current level or sensitivity&lt;/center&gt;</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>|&lt;center&gt;For an object this is the current level or sensitivity&lt;/center&gt;</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>| &#160;</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>| &#160;</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>| &lt;center&gt;For an object this is the maximum range &lt;/center&gt;</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>|&lt;center&gt;For an object this is the maximum range &lt;/center&gt;</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; 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border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; 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color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>|-</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>| &lt;center&gt;This is the lowest level or classification for the system (for SELinux this is generally <del class="diffchange diffchange-inline">&quot;</del>s0<del class="diffchange diffchange-inline">&quot;</del>, note that there are no categories).&lt;/center&gt;</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>|&lt;center&gt;This is the lowest level or classification for the system (for SELinux this is generally <ins class="diffchange diffchange-inline">'&lt;tt&gt;</ins>s0<ins class="diffchange diffchange-inline">&lt;/tt&gt;'</ins>, note that there are no categories).&lt;/center&gt;</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; 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border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>The format used in the policy language statements is fully described in the [[MLSStatements | MLS Statements]] section, however a brief overview follows.</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>The format used in the policy language statements is fully described in the [[MLSStatements | MLS Statements]] section, however a brief overview follows.</div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"></ins></div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>=== MLS / MCS Range Format ===</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>=== MLS / MCS Range Format ===</div></td></tr> <tr><td colspan="2" class="diff-lineno">Line 92:</td> <td colspan="2" class="diff-lineno">Line 87:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>'''Where:'''</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>'''Where:'''</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;"></del></div></td><td colspan="2">&#160;</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>{| border=&quot;1&quot;</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>{| border=&quot;1&quot;</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>| &lt;tt&gt;sensitivity&lt;/tt&gt;</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>| &lt;tt&gt;sensitivity&lt;/tt&gt;</div></td></tr> <tr><td colspan="2" class="diff-lineno">Line 113:</td> <td colspan="2" class="diff-lineno">Line 107:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>=== Translating Levels ===</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>=== Translating Levels ===</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>When writing policy for MLS / MCS security level components it is usual to use an abbreviated form such as &lt;tt&gt;s0, s1&lt;/tt&gt; etc. to represent sensitivities and &lt;tt&gt;c0, c1&lt;/tt&gt; etc. to represent categories. This is done simply to conserve space as they are held on files as extended attributes and also in memory. So that these labels can be represented in human readable form a translation service is provided via the &lt;tt&gt;setrans.conf&lt;/tt&gt; configuration file that uses the &lt;tt&gt;mcstransd&lt;/tt&gt; daemon. For example &lt;tt&gt;s0 = Unclassified&lt;/tt&gt;, &lt;tt&gt;s15 = TopSecret&lt;/tt&gt; and &lt;tt&gt;c0 = Finance&lt;/tt&gt;, &lt;tt&gt;c100 = SpyStories&lt;/tt&gt; (unfortunately the translation does not support spaces in words). The &lt;tt&gt;semanage(8)&lt;/tt&gt; command can be used to set up this translation and is shown in the [[GlobalConfigurationFiles | Global Configuration Files ]] section.</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>When writing policy for MLS / MCS security level components it is usual to use an abbreviated form such as &lt;tt&gt;s0, s1&lt;/tt&gt; etc. to represent sensitivities and &lt;tt&gt;c0, c1&lt;/tt&gt; etc. to represent categories. This is done simply to conserve space as they are held on files as extended attributes and also in memory. So that these labels can be represented in human readable form a translation service is provided via the &lt;tt&gt;setrans.conf&lt;/tt&gt; configuration file that uses the &lt;tt&gt;mcstransd&lt;/tt&gt; daemon. For example &lt;tt&gt;s0 = Unclassified&lt;/tt&gt;, &lt;tt&gt;s15 = TopSecret&lt;/tt&gt; and &lt;tt&gt;c0 = Finance&lt;/tt&gt;, &lt;tt&gt;c100 = SpyStories&lt;/tt&gt; (unfortunately the translation does not support spaces in words). The &lt;tt&gt;semanage(8)&lt;/tt&gt; command can be used to set up this translation and is shown in the [[GlobalConfigurationFiles | Global Configuration Files]] section.</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>== Managing Security Levels via Dominance Rules ==</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>== Managing Security Levels via Dominance Rules ==</div></td></tr> </table> RichardHaines http://arctic.selinuxproject.org/w/?title=NB_MLS&diff=944&oldid=prev RichardHaines: /* Multi-Level Security and Multi-Category Security */ 2010-05-16T14:24:57Z <p>‎<span dir="auto"><span class="autocomment">Multi-Level Security and Multi-Category Security</span></span></p> <table class='diff diff-contentalign-left'> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr style='vertical-align: top;'> <td colspan='2' style="background-color: white; color:black; text-align: center;">← Older revision</td> <td colspan='2' style="background-color: white; color:black; text-align: center;">Revision as of 14:24, 16 May 2010</td> </tr><tr><td colspan="2" class="diff-lineno">Line 1:</td> <td colspan="2" class="diff-lineno">Line 1:</td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;"></del></div></td><td colspan="2">&#160;</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>= Multi-Level Security and Multi-Category Security =</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>= Multi-Level Security and Multi-Category Security =</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>As stated in the [[NB_MAC | Mandatory Access Control (MAC)]] section as well as supporting Type Enforcement (TE), SELinux also supports MLS and MCS by adding an optional &lt;tt&gt;level&lt;/tt&gt; or &lt;tt&gt;range&lt;/tt&gt; entry to the security context. This section gives a brief introduction to MLS and MCS.</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>As stated in the [[NB_MAC | Mandatory Access Control (MAC)]] section as well as supporting Type Enforcement (TE), SELinux also supports MLS and MCS by adding an optional &lt;tt&gt;level&lt;/tt&gt; or &lt;tt&gt;range&lt;/tt&gt; entry to the security context. This section gives a brief introduction to MLS and MCS.</div></td></tr> <tr><td colspan="2" class="diff-lineno">Line 7:</td> <td colspan="2" class="diff-lineno">Line 6:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>This ensures confidentiality as the process can copy a file up to the secret level, but can never re-read that content unless the process &quot;steps up to that level&quot;, also the process cannot write files to the lower levels as confidential information would then drift downwards.</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>This ensures confidentiality as the process can copy a file up to the secret level, but can never re-read that content unless the process &quot;steps up to that level&quot;, also the process cannot write files to the lower levels as confidential information would then drift downwards.</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>To achieve this level of control, the MLS extensions to SELinux make use of constraints similar to those described in the type enforcement [[NB_TE#Constraints | Constraints]] section, except that the statement is called [[<del class="diffchange diffchange-inline">MLSSStatements </del>| mlsconstrain]]. &#160;</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>To achieve this level of control, the MLS extensions to SELinux make use of constraints similar to those described in the type enforcement [[NB_TE#Constraints | Constraints]] section, except that the statement is called [[<ins class="diffchange diffchange-inline">MLSStatements </ins>| mlsconstrain]]. &#160;</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>However, as always life is not so simple as:</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>However, as always life is not so simple as:</div></td></tr> </table> RichardHaines http://arctic.selinuxproject.org/w/?title=NB_MLS&diff=943&oldid=prev RichardHaines: New page: = Multi-Level Security and Multi-Category Security = As stated in the Mandatory Access Control (MAC) section as well as supporting Type Enforcement (TE), SELinux also support... 2010-05-16T14:23:15Z <p>New page: = Multi-Level Security and Multi-Category Security = As stated in the <a href="/page/NB_MAC" title="NB MAC"> Mandatory Access Control (MAC)</a> section as well as supporting Type Enforcement (TE), SELinux also support...</p> <p><b>New page</b></p><div><br /> = Multi-Level Security and Multi-Category Security =<br /> As stated in the [[NB_MAC | Mandatory Access Control (MAC)]] section as well as supporting Type Enforcement (TE), SELinux also supports MLS and MCS by adding an optional &lt;tt&gt;level&lt;/tt&gt; or &lt;tt&gt;range&lt;/tt&gt; entry to the security context. This section gives a brief introduction to MLS and MCS.<br /> <br /> The [http://taiga.selinuxproject.org/~rhaines/diagrams/8-security-levels.png Security Levels and Data Flows] diagram shows a simple view where security levels represent the classification of files within a file server. The security levels are strictly hierarchical and conform to the [http://en.wikipedia.org/wiki/Bell-LaPadula_model Bell-La Padula model] (BLP) in that (in the case of SELinux) a process (running at the &quot;Confidential&quot; level) can read / write at their current level but only read down levels or write up levels (the assumption here is that the process is authorised).<br /> <br /> This ensures confidentiality as the process can copy a file up to the secret level, but can never re-read that content unless the process &quot;steps up to that level&quot;, also the process cannot write files to the lower levels as confidential information would then drift downwards.<br /> <br /> To achieve this level of control, the MLS extensions to SELinux make use of constraints similar to those described in the type enforcement [[NB_TE#Constraints | Constraints]] section, except that the statement is called [[MLSSStatements | mlsconstrain]]. <br /> <br /> However, as always life is not so simple as:<br /> <br /> # Processes and objects can be given a range that represents the low and high security levels.<br /> # The security level can be more complex, in that it is a hierarchical sensitivity and zero or more non-hierarchical categories.<br /> # Allowing a process access to an object is managed by &quot;dominance&quot; rules applied to the security levels. <br /> # Trusted processes can be given privileges that will allow them to bypass the BLP rules and basically do anything (that the security policy allowed of course).<br /> # Some objects do not support separate read / write functions as they need to read / respond in cases such as networks.<br /> <br /> The sections that follow discuss the format of a security level and range, and how these are managed by the constraints mechanism within SELinux using the &quot;dominance&quot; rules.<br /> <br /> == Security Levels ==<br /> Table 1 shows the components that make up a security level and how two security levels form a range for the fourth and optional &lt;nowiki&gt;[:level]&lt;/nowiki&gt; of the [[NB_SC | security context]] within an MLS / MCS environment.<br /> <br /> The table also adds terminology in general use as other terms can be used that have the same meanings. <br /> <br /> <br /> {| border=&quot;1&quot;<br /> | &lt;center&gt;'''Security Level (or Level)'''&lt;/center&gt;<br /> <br /> &lt;center&gt;Consisting of a sensitivity and zero or more category entries:&lt;/center&gt;<br /> | colspan=&quot;2&quot; | Note that SELinux uses level, sensitivity and category in the language statements (see the [[MLSStatements | MLS Language Statements]] section), however when discussing these the following terms can also be used: labels, classifications, and compartments.<br /> <br /> |-<br /> | sensitivity [: category, ... ]<br /> <br /> |-<br /> | &lt;center&gt;also known as:&lt;/center&gt;<br /> <br /> &lt;center&gt;'''Sensitivity Label'''&lt;/center&gt;<br /> <br /> &lt;center&gt;Consisting of a classification and compartment.&lt;/center&gt;<br /> <br /> |-<br /> | colspan=&quot;3&quot; | &lt;center&gt;'''&lt;- Range -&gt; '''&lt;/center&gt;<br /> <br /> |-<br /> | &lt;center&gt;'''Low'''&lt;/center&gt;<br /> | <br /> | &lt;center&gt;'''High'''&lt;/center&gt;<br /> <br /> |-<br /> | sensitivity [: category, ... ]<br /> | &lt;center&gt;'''-'''&lt;/center&gt;<br /> | &lt;div align=&quot;right&quot;&gt;sensitivity [: category, ... ]&lt;/div&gt;<br /> <br /> |-<br /> | &lt;center&gt;For a process or subject this is the current level or sensitivity&lt;/center&gt;<br /> | <br /> | &lt;center&gt;For a process or subject this is the Clearance&lt;/center&gt;<br /> <br /> |-<br /> | &lt;center&gt;For an object this is the current level or sensitivity&lt;/center&gt;<br /> | <br /> | &lt;center&gt;For an object this is the maximum range &lt;/center&gt;<br /> <br /> &lt;center&gt;(for SELinux polyinstantiated directories)&lt;/center&gt;<br /> <br /> |-<br /> | &lt;center&gt;'''SystemLow'''&lt;/center&gt;<br /> | <br /> | &lt;center&gt;'''SystemHigh'''&lt;/center&gt;<br /> <br /> |-<br /> | &lt;center&gt;This is the lowest level or classification for the system (for SELinux this is generally &quot;s0&quot;, note that there are no categories).&lt;/center&gt;<br /> | <br /> | &lt;center&gt;This is the highest level or classification for the system (for SELinux this is generally &quot;s15:c0,c255&quot;, although note that they will be the highest set by the policy).&lt;/center&gt;<br /> <br /> |}<br /> <br /> ''Table 1: Level, Label, Category or Compartment - this table shows the meanings depending on the context being discussed.''<br /> <br /> The format used in the policy language statements is fully described in the [[MLSStatements | MLS Statements]] section, however a brief overview follows.<br /> <br /> === MLS / MCS Range Format ===<br /> The following components are used to define the MLS / MCS security levels within the security context:<br /> &lt;pre&gt;<br /> user:role:type:sensitivity[:category,...] - sensitivity [:category,...]<br /> ---------------x------------------------x-----x-------------------------x<br /> | level | - | level |<br /> | |<br /> |range|<br /> &lt;/pre&gt;<br /> <br /> '''Where:'''<br /> <br /> {| border=&quot;1&quot;<br /> | &lt;tt&gt;sensitivity&lt;/tt&gt;<br /> | Sensitivity levels are hierarchical with (traditionally) &lt;tt&gt;s0&lt;/tt&gt; being the lowest. These values are defined using the &lt;tt&gt;sensitivity&lt;/tt&gt; language statement. To define their hierarchy, the &lt;tt&gt;dominance&lt;/tt&gt; statement is used.<br /> <br /> For MLS systems the highest sensitivity is the last one defined in the dominance statement (low to high). Traditionally the maximum for MLS systems is &lt;tt&gt;s15&lt;/tt&gt; (although the maximum value for the Reference Policy is a compile time option). <br /> <br /> For MCS systems there is only one sensitivity defined, and that is &lt;tt&gt;s0&lt;/tt&gt;.<br /> <br /> |-<br /> | &lt;tt&gt;category&lt;/tt&gt;<br /> | Categories are optional (i.e. there can be zero or more categories) and they form unordered and unrelated lists of &quot;compartments&quot;. These values are defined using the &lt;tt&gt;category&lt;/tt&gt; statement, where for example &lt;tt&gt;c0.c3&lt;/tt&gt; represents a range (&lt;tt&gt;c0 c1 c3&lt;/tt&gt;) and &lt;tt&gt;c0, c3, c7&lt;/tt&gt; represent an unordered list. Traditionally the values are between &lt;tt&gt;c0&lt;/tt&gt; and &lt;tt&gt;c255&lt;/tt&gt; (although the maximum value for the Reference Policy is a compile time option).<br /> <br /> |-<br /> | &lt;tt&gt;level&lt;/tt&gt;<br /> | The level is a combination of the sensitivity and category values that form the actual security level. These values are defined using the &lt;tt&gt;level&lt;/tt&gt; statement.<br /> <br /> |}<br /> <br /> <br /> === Translating Levels ===<br /> When writing policy for MLS / MCS security level components it is usual to use an abbreviated form such as &lt;tt&gt;s0, s1&lt;/tt&gt; etc. to represent sensitivities and &lt;tt&gt;c0, c1&lt;/tt&gt; etc. to represent categories. This is done simply to conserve space as they are held on files as extended attributes and also in memory. So that these labels can be represented in human readable form a translation service is provided via the &lt;tt&gt;setrans.conf&lt;/tt&gt; configuration file that uses the &lt;tt&gt;mcstransd&lt;/tt&gt; daemon. For example &lt;tt&gt;s0 = Unclassified&lt;/tt&gt;, &lt;tt&gt;s15 = TopSecret&lt;/tt&gt; and &lt;tt&gt;c0 = Finance&lt;/tt&gt;, &lt;tt&gt;c100 = SpyStories&lt;/tt&gt; (unfortunately the translation does not support spaces in words). The &lt;tt&gt;semanage(8)&lt;/tt&gt; command can be used to set up this translation and is shown in the [[GlobalConfigurationFiles | Global Configuration Files ]] section.<br /> <br /> == Managing Security Levels via Dominance Rules ==<br /> As stated earlier, allowing a process access to an object is managed by &quot;dominance&quot; rules applied to the security levels. These rules are as follows:<br /> <br /> #: '''Security Level 1 dominates Security Level 2''' - If the sensitivity of Security Level 1 is equal to or higher than the sensitivity of Security Level 2 and the categories of Security Level 1 are the same or a superset of the categories of Security Level 2.<br /> <br /> #: '''Security Level 1 is dominated by Security Level 2''' - If the sensitivity of Security Level 1 is equal to or lower than the sensitivity of Security Level 2 and the categories of Security Level 1 are a subset of the categories of Security Level 2.<br /> <br /> #: '''Security Level 1 equals Security Level 2''' - If the sensitivity of Security Level 1 is equal to Security Level 2 and the categories of Security Level 1 and Security Level 2 are the same set (sometimes expressed as: both Security Levels dominate each other).<br /> <br /> #: '''Security Level 1 is incomparable to Security Level 2''' - If the categories of Security Level 1 and Security Level 2 cannot be compared (i.e. neither Security Level dominates the other).<br /> <br /> To illustrate the usage of these rules, the [http://taiga.selinuxproject.org/~rhaines/diagrams/t2-MLS-Security-Levels.png MLS Security Levels example] table lists the security level attributes in a table to show example files (or documents) that have been allocated labels such as &lt;tt&gt;s3:c0&lt;/tt&gt;. The process that accesses these files (e.g. an editor) is running with a range of &lt;tt&gt;s0 - s3:c1.c5&lt;/tt&gt; and has access to the files highlighted within the grey box area.<br /> <br /> As the MLS &lt;tt&gt;dominance&lt;/tt&gt; Statement is used to enforce the sensitivity hierarchy, the security levels now follow that sequence (lowest = &lt;tt&gt;s0&lt;/tt&gt; to highest = &lt;tt&gt;s3&lt;/tt&gt;) with the categories being unordered lists of &quot;compartments&quot;. To allow the process access to files within its scope and within the dominance rules, the process will be constrained by using the &lt;tt&gt;mlsconstrain&lt;/tt&gt; statement as illustrated in the [http://taiga.selinuxproject.org/~rhaines/diagrams/9-mls-constrain.png MLS constrain] diagram. <br /> <br /> So using the [http://taiga.selinuxproject.org/~rhaines/diagrams/9-mls-constrain.png MLS constrain] diagram:<br /> <br /> # To allow write-up, the source level (&lt;tt&gt;l1&lt;/tt&gt;) must be '''dominated by''' the target level (&lt;tt&gt;l2&lt;/tt&gt;):<br /> #: Source level = &lt;tt&gt;s0:c3&lt;/tt&gt; or &lt;tt&gt;s1:c1&lt;/tt&gt;<br /> #: Target level = &lt;tt&gt;s2:c1.c4&lt;/tt&gt;<br /> <br /> As can be seen, either of the source levels are '''dominated by''' the target level.<br /> <br /> # To allow read-down, the source level (&lt;tt&gt;l1&lt;/tt&gt;) must '''dominate''' the target level (&lt;tt&gt;l2&lt;/tt&gt;):<br /> #: Source level = &lt;tt&gt;s2:c1.c4&lt;/tt&gt;<br /> #: Target level = &lt;tt&gt;s0:c3&lt;/tt&gt;<br /> <br /> As can be seen, the source level does '''dominate''' the target level.<br /> <br /> However in the real world the SELinux MLS Reference Policy does not allow the write-up unless the process has a special privilege (by having the domain type added to an attribute), although it does allow the read-down. The default is to use &lt;tt&gt;l1 eq l2&lt;/tt&gt; (i.e. the levels are equal). The reference policy MLS source file (policy/mls) shows these mlsconstrain statements.<br /> <br /> == MLS Labeled Network and Database Support ==<br /> Networking for MLS is supported via the NetLabel CIPSO (commercial IP security option) service as discussed in the [[NB_Networking | SELinux Networking Support]] section.<br /> <br /> PostgreSQL supports labeling for MLS database services as discussed in the &quot;[http://wiki.postgresql.org/wiki/SEPostgreSQL_Development Security-Enhanced PostgreSQL Security Wiki]&quot;.<br /> <br /> == Common Criteria Certification ==<br /> While the [http://www.commoncriteriaportal.org/ Common Criteria] certification process is beyond the scope of this Notebook, it is worth highlighting that specific Red Hat GNU / Linux versions of software, running on specific hardware platforms with SELinux / MLS policy enabled, have passed the Common Criteria evaluation process. Note, for the evaluation (and deployment) the software and hardware are tied together, therefore whenever an update is carried out, an updated certificate should be obtained.<br /> <br /> The Red Hat evaluation process cover the:<br /> * Labeled Security Protection Profile ([http://www.commoncriteriaportal.org/files/ppfiles/lspp.pdf LSPP] ) - This describes how systems that implement security labels (i.e. MLS) should function.<br /> * Controlled Access Protection Profile ([http://www.commoncriteriaportal.org/files/ppfiles/capp.pdf CAPP]) - This describes how systems that implement DAC should function.<br /> <br /> An interesting point:<br /> * Both Red Hat Linux 5.1 and Microsoft Server 2003 (with XP) have both been certified to EAL4+ , however while the evaluation levels may be the same the Protection Profiles that they were evaluated under were: Microsoft CAPP only, Red Hat CAPP and LSPP. Therefore always look at the protection profiles as they define what was actually evaluated.<br /> <br /> <br /> ----<br /> &lt;references/&gt;</div> RichardHaines