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Access Control

Administrators often want to control access to their applications based on different policies and attributes rather than static user roles. To handle this, Qlik Associative Engine supports Attribute-Based Access Control (ABAC), which lets you control application access through attribute-based rules.

Rules

When ABAC is enabled, users are granted access based on rules. Each rule is a conditional expression that evaluates to either true or false, and each rule contains a property that determines which actions the rule grants, or denies.

Note

When the ABAC feature is enabled, all user access is disabled by default. You must include rules when enabling ABAC to provide user access.

Rules overview

Rules are constructed using attributes that defines user access. Consider the following rule:

user.sub = "ada-lovelace" and resource._resourcetype = "App" and resource._actions = {"create", "update", "read"}

Notice that the rule consists of key-value pairs linked by logical operators, in this case, and.

This rule states that if the user is ada-lovelace and the accessed resource type is App, grant the actions create, update, and read.

Note

Only the _actions attribute is mandatory. The user.sub and resource._resourcetype expressions could be omitted and the rule would still be valid. See Actions for more details.

Rule files

Rules are defined in two text files: a Deny rules file and an Allow rules file. The Deny rules file is evaluated first, and rules are evaluated in the order that they appear. A rule is written on a single row.

The Deny rules file denies access to perform actions (create, read, update, etc.). If any rule in the Deny rules file evaluates to true, access is immediately denied for the actions listed and rules evaluation stops.

The Allow rule file grants access to perform actions (create, read, update, etc.). If a rule in the Allow rule file evaluates to true, access is granted for the actions listed. Rule evaluation continues for the entire file, possibly accumulating access to more actions based on other rules.

Note

When you start a session, Qlik Associative Engine reads the rules files immediately. If you modify the rules files, you need to restart the session or make a REST call to trigger the engine to reread the rules files.

Engine configuration for ABAC

Before you start the Qlik Associative Engine, you must enable ABAC and set the rules files paths with command-line switches.

ABAC-related command-line switches

Switch	Values	Default	Description
EnableABAC	0 or 1	0	Enabling/disabling of ABAC rule evaluation.
SystemDenyRulePath	File path	N/A	File path to the Deny rules file.
SystemAllowRulePath	File path	N/A	File path to the Allow rules file.

ABAC examples

To start Qlik Associative Engine instance as a Docker container, enable ABAC, and set the Allow and Deny rules file paths, run the following command:

docker run -v <host folder path>:<container folder path> qlikcore/engine:<version> \
    -S EnableABAC=1 \
    -S SystemAllowRulePath=/<container folder path>/allow.txt \
    -S SystemDenyRulePath=/<container folder path>/deny.txt

For more examples using ABAC, see the core-authorization repository, which contains running code examples on how to enable ABAC and how to provide rules to Qlik Associative Engine.

Rules language

Before you write any ABAC rules, it is important to understand the syntax and semantics of the rules language, and how they interact with each other.

Rules language concepts

Rules are built upon three concepts:

• User - The subject that is granted or denied access.
• Resource - The object to which actions are granted or denied.
• Action - The operation performed on a resource.

These concepts are used to build the expressions in the rules language.

Rules language expressions

Rules are made of expressions, and these expressions are written with logical and comparison operators. Consequently, a rule evaluates to either true or false depending on the expressions and the types of operators contained within the rule.

The logical operators are:

Operator	Meaning
!	Logical negation (not)
and, &&	Logical conjunction (and)
or, ||	Logical disjunction (or)

The comparison operators are:

Operator	Meaning
=	Equality
==	Strict equality
!=	Inequality
!==	Strict inequality
like	Wildcard string matching
matches	Regular expression string matching

The user object

All rules are evaluated in the context of a user. In rule expressions, the user is represented by the user object.

User attribute

Attribute	Description
user.sub	The identifier of the user. This user.sub gets the value of the mandatory sub attribute in the JWT.

Also, user contains all attributes defined in the JWT header that are used to authenticate the user.

For more information about attributes in the JWT header, see JSON web token.

Example

{
  "sub": "john-doe",
  "name": "John Doe",
  "employeeType": "developer",
  "tags": ["research"],
  "custom": {
    "country": "sweden"
  }
}

The user.sub is john-doe, based on the sub attribute. All of the attributes are attributes of user. An example of a rule using some of the user attributes looks like the following:

user.sub = "john-doe" and user.employeeType = "developer" and user.custom.country = "sweden" and resource._actions = "*"

In example rule above, the user john-doe is granted access for all actions to all resources.

The resource object

A resource object is a generic concept that can represent applications, or objects within applications. A resource object consists of attributes that can be used in rule expressions. In rule expressions, the resource being accessed is represented by the resource object.

Common resource attributes

There are different resource types, but all resources share some common attributes.

Attribute	Description
resource.description	The resource description. Can be empty.
resource.id	The unique identifier for the resource.
resource.owner	The owner of the resource.
resource._resourcetype	The type of the resource being accessed. Equal to "App" or "App.Object".
resource._actions	The actions granted on the resource. See Actions for more details.

Type-specific resource attributes

Depending on the type of resource that is being accessed, resource may carry additional attributes. If the resource type is "App", there are no additional attributes. If the resource type is "App.Object", then resource has the following additional attributes:

Attribute	Description	Example condition
resource._objecttype	The object type.	resource._objecttype = "field" or resource._objecttype = "my-generic-object"
resource.app	Reference to the app resource that the object is part of.	resource.app.owner = "john-doe"

The app attribute

When the common resource attribute is resource._resourcetype = "App.Object", then the type-specific resource attribute resource.app contains a reference to the app resource. This means that all attributes and built-in functions are available on resource.app.

The HasPrivilege built-in function

If the user making the request has already been granted access for the provided action, then the built-in HasPrivilege(<action>) function returns true, otherwise it returns false.

The syntax of the HasPrivilege function is the following:

resource.HasPrivilege(ACTION)

The ACTION parameter is required. Its value can be any of the supported actions described in Actions.

Consider the following rules:

user.country = "uk" and resource._resourcetype = "App.Object" and resource._actions = "create"
resource._resourcetype = "App.Object" and resource.HasPrivilege("create") and resource._actions = {"read", "update"}

The first rule grants the create action to a user.

The second rules contains the HasPrivilege function that will evaluate to true if the create action has already been granted to the user. Because of the first rule, it is evaluated as true. As a result, the second rule adds the read and update actions to the user. The user is granted create,read,and update actions from two rules.

Actions

An action is an operation that a user can perform on a Qlik Associative Engine resource. The actions are:

Action	Description
create	Create a resource.
read	Read a resource.
update	Update a resource.
reload	Reload an application.
delete	Delete a resource.
import	Import an application.
export	Export an application.
export data	Export data from an object.

Note

If a reload script requires other actions, for example to create variables in the application, then the user must be granted the required actions that are called in the script. For example: resource._resourcetype = "App.Object" && resource._objecttype = "variable" && resource._action = "create".

The _actions attribute

In rule expressions, the resource attribute _actions has special semantics:

• resource._actions is always used as left operand with the = operator. Other usage is undefined behavior.
• The expression resource._actions = (EXPRESSION) always evaluates to true.
• The expression resource._actions = (EXPRESSION) has the side effect of accumulating the actions given by the right operand which is a single action or a list of actions.
• resource._actions = "*" can be used to grant all actions, where "*" is wildcard for all actions.

If resource._actions = (EXPRESSION) is ommitted from a rule, any actions that are granted are not accumulated. It is good practice to write all rules so that the final expression in the rule involves resource._actions.

Consider the following rule:

user.country = "uk" and resource._actions = {"read", "update"}

When the rule evaluates to true, the user from the UK is granted read and update actions.

Note that granted actions accumulate in the order in which the rules are evaluated.

Consider the following rule:

user.country = "uk" and resource._actions = {"read", "update"}
user.roles = {"developer"} and resource._actions = {"create"}

When the first rule evaluates to true, the user from the UK is granted read and update actions.

If the user from UK has a user role of developer, then the second rule will evaluate to true, and the user from the UK is granted the create action. The actions accumulate, so the user from UK has read, update, and create actions.

Note

Do not rely on accumulating actions. It is better to be explicit about which actions to grant.

To avoid relying on the accumulation of actions, the example rules above can be written as the following:

user.country = "uk" and resource._actions = {"read", "update"}
user.roles = {"developer"} and resource._actions = {"read", "update", "create"}

Rule operators

Rules contain expressions that are joined together with logical and comparison operators. Comparison operators have precedence over logical operators. Parantheses are supported to override precedence.

Logical Operators

There are three logical operators for rule expressions: not, and, and or.

! (not)

The not operator returns the logical negation of its operand.

Returns	When
true	Operand is false
false	Operand is true

Syntax

!(EXPRESSION)

Example

Given that user.country is "uk":

# Evaluates to false
!(resource.country = "UK")

# Evaluates to true
!(resource.country = "SE")

and, &&

This operator returns the logical conjuction of its operands.

Returns	When
true	All operands are true
false	Any operand is false

Syntax

(EXPRESSION) (and | &&) (EXPRESSION)

Examples

Given that user.country is "uk" and user.sub is "john-doe":

# Evaluate to true
(user.country = "UK") && (user.sub = "john-doe")
(user.country = "UK") and (user.sub = "john-doe")

# Evaluate to false
(user.country = "SE") && (user.sub = "john-doe")
(user.country = "UK") and (user.sub = "bill-smith")

or, ||

This operator returns the logical disjunction of its operands.

Returns	When
true	Operands are true
true	Any operand is true
false	All operands are false

Syntax

(EXPRESSION) (|| | or) (EXPRESSION)

Examples

Given that user.country is "uk" and user.sub is "john-doe":

# Evaluate to true
(user.country = "UK") || (user.sub = "john-doe")
(user.country = "UK") || (user.sub = "bill-smith")
(user.country = "SE") or (user.sub = "john-doe")

# Evaluate to false
(user.country = "SE") or (user.sub = "bill-smith")
(user.country = "SE") || (user.sub = "bill-smith")

Comparison Operators

There are six comparison operators for rule expressions: equal, strictly equal, not equal, strictly not equal, like, and matches.

= (equal)

This equal operator returns true only if its operands are equal.

Returns	When
true	Operands are equal
false	Operands are not equal

Note

equal string comparison is case insensitive (see == for case sensitive comparison). If one of the operands is a list, only one value in the list needs to be equal.

Syntax

(EXPRESSION) = (EXPRESSION)

Examples

Given that user.country is "uk":

# Evaluate to true
user.country = "UK"
user.country = "uk"
user.country = {"se", "us", "uk"}

# Evaluate to false
user.org = "United Kingdom"
user.org = {"se", "dk", "ca"}

== (strictly equal)

The strictly equal operator returns true only if its operands are strictly equal.

Returns	When
true	Operands are strictly equal
false	Operands are not equal

Note

strictly equal string comparison is case sensitive (see = for case insensitive comparison). If one of the operands is a list, only one value in the list needs to be strictly equal.

Syntax

(EXPRESSION) == (EXPRESSION)

Examples

Given that user.country is "uk":

# Evaluate to true
user.country == "uk"
user.country == {"se", "uk", "ca"}

# Evaluate to false
user.country == "UK"
user.country == {"SE", "UK", "CA"}

!= (not equal)

The not equal operator returns true only if its operands are not equal.

Returns	When
true	Operands are not equal
false	Operands are equal

Note

not equal string comparison is case insensitive (see !== for case sensitive comparison). If one of the operands is a list, only one value in the list needs to be unequal.

Syntax

(EXPRESSION) != (EXPRESSION)

Examples

Given that user.country is "uk":

# Evaluate to true
resource.org != "SE"
resource.org != {"SE", "UK", "uk"}

# Evaluate to false
resource.org != "UK"
resource.org != {"uk", "UK"}

!== (strictly not equal)

The strictly not equal operator returns true only if its operands are strictly not equal.

Returns	When
true	Operands are strictly not equal
false	Operands are equal

Note

String comparison is case sensitive (see != for case insensitive comparison). If one of the operands is a list, only one value in the list needs to be strictly unequal.

Syntax

(EXPRESSION) !== (EXPRESSION)

Examples

Given that user.country is "uk":

# Evaluate to true
user.country !== "UK"
user.country !== {"uk", "UK", "se"}

# Evaluate to false
resource.org !== "uk"
resource.org !== {"uk"}

like

The like operator returns true only if the left operand matches the wildcard pattern given by the right operand.

Returns	When
true	Left operand matches the wildcard in the right operand.
false	Left operand does not match the wildcard in right operand.

Note

The comparison is case insensitive.

Wildcard	Description
?	Matches any single character.
*	Matches zero or more characters.

The escape character \ can be used to match ?, *, and \ using the escaped sequences - \?, \*, and \\.

Syntax

(EXPRESSION) like (EXPRESSION)

Examples

Given that user.region is "us-east" or "us-west":

# Evaluate to true
user.region like "us-*"
user.region like "US-*"
user.region like "??-*"

# Evaluate to false
user.region like "us-?"
user.region like "uk-*"

matches

The matches operator returns true only if the left operand matches the regular expression given by the right operand.

Returns	When
true	Left operand matches the regular expression in the right operand.
false	Left operand does not match the regular expression in the right operand.

Syntax

(EXPRESSION) matches (EXPRESSION)

Examples

To match users from deployments 1 or 2 from any US region (east, west etc.):

user.region matches "us-[^-]+-(1|2)"

This regular expression matches regions starting with us-, followed by one ore more characters that are anything but -, followed by -1 or -2.

Adding an existing app

To add an existing app (qvf) to an engine that is running access control, you must import the app. You can do this with the engine REST API. The access control feature requires the app to follow a specific file structure, which is created when an app is imported.

Example

In this example, we describe how to import and enable access control for an app. For this example, we will import the African Urbanization use case.

First, we start the Qlik Associative Engine with the following parameters:

"-S", "AcceptEULA=no", # change to 'yes' if you accept the Qlik Core EULA
"-S", "LicenseServiceUrl=<LicenseService adress>",
"-S", "DocumentDirectory=<directory for doc>",
"-S", "EnableABAC=1",
"-S", "SystemAllowRulePath=<directory for rules>"

Next, we call the engine REST API to import the Shared-Africa-Urbanization.qvf:

POST /v1/apps/import

curl -s --data-binary @Shared-Africa-Urbanization.qvf http://<adress to engine>/v1/apps/import

The engine returns information about the import. It looks similar to this:

{"attributes":{"id":"09aa1749-52a0-43ad-a525-3699d6e9f866","name":"","description":"","thumbnail":"","lastReloadTime":"2018-06-13T13:34:41.436Z","createdDate":"","modifiedDate":"","owner":"Personal\\Me","dynamicColor":"","published":false,"publishTime":"","custom":{},"_resourcetype":"app"},"privileges":["read","create","update","delete","reload","import","export","exportdata","publish","duplicate","approve"],"create":[{"resource":"\"sheet\"","canCreate":true},{"resource":"\"bookmark\"","canCreate":true},{"resource":"\"story\"","canCreate":true},{"resource":"\"dimension\"","canCreate":true},{"resource":"\"measure\"","canCreate":true},{"resource":"\"masterobject\"","canCreate":true},{"resource":"\"folderconnection\"","canCreate":true},{"resource":"\"internetconnection\"","canCreate":true}]}

Notice that the engine returns an id in the response body. This id is the name of the imported app. The Shared-Africa-Urbanization.qvf app now follows the same rules that are defined for access control.

For more information, see this commit.