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Version: v8

Header Rules

Helps to modify headers, cookies, and arguments in the request sent to the back-end server as well as modifying response sent to the client.

Overview​

We have introduced Header rules by which application owners can manipulate request headers, cookies, and arguments in request as well as response headers. Users can create/update header rules at run time with on-the-fly updates. It has the functionality to add/remove/update any cookie/header/arguments in the request to the web-server(back-end) as well as respond to the client.

header rules

How to Use:​

  1. Go to WAF > Listeners > Rules > Header Rules.
  2. Click on Add Rule and set relevant parameters described below.
  3. Click on Save Changes

Description​

Rule Name​

Specify a rule name to identify the rule which is to be created. The rule name takes alphanumeric input.

    Accepted values: String

    Default: Blank
Message​

Specify a rule message containing a detailed description to identify the rule which is to be created.

    Accepted values: Description for the rule in String format

    Default: Blank
Rule Priority​

User can define the rule's priority among various other custom error rules.

    Accepted values: Integer

    Default: 0
URI​

Specify the URI or regex for which rule will be applied.

    Accepted values: URI

    Default: Blank
Method​

Select the HTTP method for the rule to validate when matched with the request.

    Accepted values: ALL / GET / POST / PUT / DELETE / PATCH / HEAD / OPTIONS

    Default: Blank
Evaluation Phase​

Select the evaluation phase for the rule i.e. Request or Response.

    Accepted values: Request Phase / Response Phase

    Default: Request Phase
Rule Action​

The rule action determines what action (add/remove/overwrite) the rule will perform. The accepted values are:

    Accepted values: Remove Header / Add Header / Add Cookie / Overite Header / Overite Cookie / Remove Cookie 

    Default: Blank

  1. ADD: This condition will allow adding a value at the specified location.

  2. REMOVE: This condition will allow removing a value at the specified location.

  3. OVERWRITE: This condition will allow overwriting a value at the specified location.

If the action is ADD then another field is required I.e., Value that will be added for the specified Parameter.

If the action is REMOVE, then the specified parameter is removed.

If the action is OVERWRITE, then two other fields are required first is Search Pattern (string/regex that should match the existing value) and Replace (the string that should be overwritten). We can capture string from the PCRE capturing group using position with a prefix of '$'.

Note

In order to escape the dollar($) character in the replace, add the dollar symbol twice.

Attribute Name​

Specify the attribute name which need to add/delete/overwrite with rule.

    Accepted values: String

    Default: Blank
Attribute Value​

Specify the attribute value which will be mentioned in the attribute.

    Accepted values: String

    Default: Blank
Add Condition​

The user can specify some request/response-based conditions which can be used as mandatory conditions to be fulfilled to apply the rule.

To configure the parameter of the conditions please refer to the following link: Conditions