Base security model

The Base security model lets you implement basic logic.

A PSL file containing a description of the Base security model is located in the KasperskyOS SDK at the following path:

toolchain/include/nk/base.psl

Base security model object

The base.psl file contains a declaration that creates a Base security model object named base. Consequently, inclusion of the base.psl file into the solution security policy description will create a Base security model object by default. Methods of this object can be called without indicating the object name.

A Base security model object does not have any parameters.

A Base security model object can be covered by a security audit. There are no audit completion conditions specific to the Base security model.

It is necessary to create additional objects of the Base security model in the following cases:

• You need to configure a security audit differently for different objects of the Base security model (for example, you can apply different audit profiles or different audit configurations of the same profile for different objects).
• You need to distinguish between calls of methods provided by different objects of the Base security model (audit data includes the name of the security model method and the name of the object that provides this method, so you can verify that the method of a specific object was called).

Base security model methods

The Base security model contains the following rules:

• grant ()

  It has a parameter of the () type. It returns the "granted" result.

  Example:

  /* A client of the foo class is allowed to query

  * a server of the bar class. */

  request src=foo dst=bar { grant () }

• assert <Boolean>

  It returns the "granted" result if the true value is passed via the parameter. Otherwise it returns the "denied" result.

  Example:

  /* Any client in the solution will be allowed to query a server of the foo class

  * by calling the Send method of the net.Net service if the port parameter of the Send method

  * will be used to pass a value greater than 80. Otherwise any client in the solution

  * will be prohibited from querying a server of the foo class by calling the Send method

  * of the net.Net service. */

  request dst=foo endpoint=net.Net method=Send { assert (message.port > 80) }

• deny <Boolean | ()>

  It returns the "denied" result if the true or () value is passed via the parameter. Otherwise it returns the "granted" result.

  Example:

  /* A server of the foo class is not allowed to respond

  * to a client of the bar class. */

  response src=foo dst=bar { deny () }

• set_level <UInt8>

  It sets the security audit level equal to the value passed via this parameter. It returns the "granted" result. (For more details about the security audit level, see "Describing security audit profiles".)

  Example:

  /* An entity of the foo class will receive the "allowed" decision from the

  * Kaspersky Security Module if it calls the SetAuditLevel security interface method

  * to change the security audit level. */

  security src=foo method=SetAuditLevel { set_level (message.audit_level) }

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