Unix: Sshd Parameter

Description

The Unix: Sshd Parameter test is used to check the contents of an sshd configuration file, by looking at individual blocks of text.

The textfilecontent54_object element is used by a textfilecontent54_test to define the specific block(s) of text of a file(s) to be evaluated. The textfilecontent54_object will only collect regular files on UNIX systems.

The set of files to be evaluated may be identified with either a complete filepath or a path and filename. Only one of these options may be selected.

The textfilecontent54_state element contains entities that are used to check the file path and name, as well as the text block in question and the value of the subexpressions.

Technical Details

Artifact Parameters

unix.sshd_parameter_v1

Name	Type	Description
parameter	string	The sshd config parameter to test. Cannot be blank.

Supported Test Types

Existence Test

Equals

Equal

Not Equal

Less Than

Less Than Or Equal

Greater Than

Greater Than Or Equal

Pattern Match

Pattern Not Match

Test Type Parameters

equals
equal
not equal
less than
less than or equal
greater than
greater than or equal
pattern match
pattern not match

Name	Type	Description
value	string	The value to be tested.
data_type	string	The data type of the value.

NOTE: The data_type parameter is governed by a constraint allowing only the following values:

boolean
float
int
string
version
set

existence_test

Name	Type	Description
value	string	The value to be tested.

NOTE: The value parameter is governed by a constraint allowing only the following values:

all_exist
any_exist
at_least_one_exists
none_satisfy
none_exist
only_one_exists

Generated Content

equals
equal
not equal
less than
less than or equal
greater than
greater than or equal
pattern match
pattern not match

XCCDF+AE

This is what the AE check looks like, inside a Rule, in the XCCDF.

<xccdf:complex-check operator="AND">
  <xccdf:check system="https://benchmarks.cisecurity.org/ae/0.5">
    <xccdf:check-content>
      <ae:artifact_expression id="xccdf_org.cisecurity.benchmarks_ae_[SECTION-NUMBER]">
        <ae:artifact_oval_id>[ARTIFACT-OVAL-ID]</ae:artifact_oval_id>
        <ae:title>[RECOMMENDATION_TTILE]</ae:title>
        <ae:artifact type="[ARTIFACT-TYPE-NAME]">
          <ae:parameters>
            <ae:parameter dt="string" name="parameter">[parameter.value]</ae:parameter>
          </ae:parameters>
        </ae:artifact>
        <ae:test type="[TEST-TYPE-NAME]">
          <ae:parameters>
            <ae:parameter dt="string" name="value">[value.value]</ae:parameter>
            <ae:parameter dt="string" name="data_type">[data_type.value]</ae:parameter>
          </ae:parameters>
        </ae:test>
        <ae:profiles>
          <ae:profile idref="xccdf_org.cisecurity.benchmarks_profile_Level_1" />
        </ae:profiles>
      </ae:artifact_expression>
    </xccdf:check-content>
  </xccdf:check>
</xccdf:complex-check>

SCAP

XCCDF

For unix.sshd_parameter_v1 equals, equal, not equal, less than, less than or equal, greater than, greater than or equal, pattern match, and pattern not match artifacts, an XCCDF Value element is generated.

<Value
  id="xccdf_org.cisecurity.benchmarks_value_[ARTIFACT-OVAL-ID]_var"
  type="string"
  operator="equals">
  <title>[RECOMMENDATION-TITLE]</title>
  <description>This value is used in Rule: [RECOMMENDATION-TITLE]</description>
  <value>[value.value]</value>
</Value>

For unix.sshd_parameter_v1 equals, equal, not equal, less than, less than or equal, greater than, greater than or equal, pattern match, and pattern not match artifacts, the XCCDF check looks like this.

<check system="http://oval.mitre.org/XMLSchema/oval-definitions-5">
  <check-export
    export-name="oval:org.cisecurity.benchmarks.[PLATFORM]:var:[ARTIFACT-OVAL-ID]"
    value-id="xccdf_org.cisecurity.benchmarks_value_[ARTIFACT-OVAL-ID]_var" />
  <check-content-ref
    href="[BENCHMARK-TITLE]-oval.xml"
    name="oval:org.cisecurity.benchmarks.[PLATFORM]:def:[ARTIFACT-OVAL-ID]" />
</check>

OVAL

Test

<textfilecontent54_test
  xmlns="http://oval.mitre.org/XMLSchema/oval-definitions-5#independent"
  id="oval:org.cisecurity.benchmarks.[PLATFORM]:tst:[ARTIFACT-OVAL-ID]"
  check_existence="at_least_one_exists"
  check="all"
  comment="[ARTIFACT-TITLE]"
  version="1">
  <object object_ref="oval:org.cisecurity.benchmarks.[PLATFORM]:obj:[ARTIFACT-OVAL-ID]" />
  <state state_ref="oval:org.cisecurity.benchmarks.[PLATFORM]:ste:[ARTIFACT-OVAL-ID]" />
</textfilecontent54_test>

Object

<textfilecontent54_object
  xmlns="http://oval.mitre.org/XMLSchema/oval-definitions-5#independent"
  id="oval:org.cisecurity.benchmarks.[PLATFORM]:obj:[ARTIFACT-OVAL-ID]"
  comment="[ARTIFACT-TITLE]"
  version="1">
  <filepath>/etc/ssh/sshd_config</filepath>
  <pattern operation="pattern match">
    [pattern.value]
  </pattern>
  <instance
    datatype="int"
    operation="equals">
      1
  </instance>
</textfilecontent54_object>

State

<textfilecontent54_state
  xmlns="http://oval.mitre.org/XMLSchema/oval-definitions-5#independent"
  id="oval:org.cisecurity.benchmarks.[PLATFORM]:ste:[ARTIFACT-OVAL-ID]"
  comment="[ARTIFACT-TITLE]"
  version="1">
  <subexpression
    datatype="[datatype.value]"
    operation="[operation.value]"
    var_ref="oval:org.cisecurity.benchmarks.[PLATFORM]:var:[ARTIFACT-OVAL-ID]" />
</textfilecontent54_state>

Variable

<external_variable
  id="oval:org.cisecurity.benchmarks.[PLATFORM]:var:[ARTIFACT-OVAL-ID]"
  datatype="[datatype.value]"
  version="1"
  comment="This value is used in [RECOMMENDATION-TITLE]" />

YAML

artifact-expression:
  artifact-unique-id: "[ARTIFACT-OVAL-ID]"
  artifact-title: "[ARTIFACT-TITLE]"
  artifact:
    type: "[ARTIFACT-TYPE-NAME]"
    parameters:
      - parameter:
          name: "parameter"
          dt: "string"
          value: "[parameter.value]"
  test:
    type: "[TEST-TYPE-NAME]"
    parameters:
      - parameter:
          name: "value"
          dt: "string"
          value: "[value.value]"
      - parameter:
          name: "data_type"
          dt: "string"
          value: "[data_type.value]"

JSON

{
  "artifact-expression": {
    "artifact-unique-id": "[ARTIFACT-OVAL-ID]",
    "artifact-title": "[ARTIFACT-TITLE]",
    "artifact": {
      "type": "[ARTIFACT-TYPE-NAME]",
      "parameters": [
        {
          "parameter": {
            "name": "parameter",
            "type": "string",
            "value": "[parameter.value]"
          }
        }
      ]
    },
    "test": {
      "type": "[TEST-TYPE-NAME]",
      "parameters": [
        {
          "parameter": {
            "name": "value",
            "type": "string",
            "value": "[value.value]"
          }
        },
        {
          "parameter": {
            "name": "data_type",
            "type": "string",
            "value": "[data_type.value]"
          }
        }
      ]
    }
  }
}