Request Syntax Request Parameters Response Syntax Response Elements Errors See Also

CreateSizeConstraintSet

Note

AWS WAF Classic support will end on September 30, 2025.

This is AWS WAF Classic documentation. For more information, see AWS WAF Classic in the developer guide.

For the latest version of AWS WAF , use the AWS WAFV2 API and see the AWS WAF Developer Guide. With the latest version, AWS WAF has a single set of endpoints for regional and global use.

Creates a SizeConstraintSet. You then use UpdateSizeConstraintSet to identify the part of a web request that you want AWS WAF to check for length, such as the length of the User-Agent header or the length of the query string. For example, you can create a SizeConstraintSet that matches any requests that have a query string that is longer than 100 bytes. You can then configure AWS WAF to reject those requests.

To create and configure a SizeConstraintSet, perform the following steps:

Use GetChangeToken to get the change token that you provide in the ChangeToken parameter of a CreateSizeConstraintSet request.
Submit a CreateSizeConstraintSet request.
Use GetChangeToken to get the change token that you provide in the ChangeToken parameter of an UpdateSizeConstraintSet request.
Submit an UpdateSizeConstraintSet request to specify the part of the request that you want AWS WAF to inspect (for example, the header or the URI path) and the value that you want AWS WAF to watch for.

For more information about how to use the AWS WAF API to allow or block HTTP requests, see the AWS WAF Developer Guide.

Request Syntax


{
   "ChangeToken": "string",
   "Name": "string"
}

Request Parameters

For information about the parameters that are common to all actions, see Common Parameters.

The request accepts the following data in JSON format.

ChangeToken

The value returned by the most recent call to GetChangeToken.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 128.

Pattern: .*\S.*

Required: Yes

Name

A friendly name or description of the SizeConstraintSet. You can't change Name after you create a SizeConstraintSet.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 128.

Pattern: .*\S.*

Required: Yes

Response Syntax


{
   "ChangeToken": "string",
   "SizeConstraintSet": { 
      "Name": "string",
      "SizeConstraints": [ 
         { 
            "ComparisonOperator": "string",
            "FieldToMatch": { 
               "Data": "string",
               "Type": "string"
            },
            "Size": number,
            "TextTransformation": "string"
         }
      ],
      "SizeConstraintSetId": "string"
   }
}

Response Elements

If the action is successful, the service sends back an HTTP 200 response.

The following data is returned in JSON format by the service.

ChangeToken

The ChangeToken that you used to submit the CreateSizeConstraintSet request. You can also use this value to query the status of the request. For more information, see GetChangeTokenStatus.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 128.

Pattern: .*\S.*

SizeConstraintSet

A SizeConstraintSet that contains no SizeConstraint objects.

Type: SizeConstraintSet object

Errors

For information about the errors that are common to all actions, see Common Errors.

WAFDisallowedNameException

The name specified is invalid.

HTTP Status Code: 400

WAFInternalErrorException

The operation failed because of a system problem, even though the request was valid. Retry your request.

HTTP Status Code: 500

WAFInvalidAccountException

The operation failed because you tried to create, update, or delete an object by using an invalid account identifier.

HTTP Status Code: 400

WAFInvalidParameterException

The operation failed because AWS WAF didn't recognize a parameter in the request. For example:

You specified an invalid parameter name.
You specified an invalid value.
You tried to update an object (ByteMatchSet, IPSet, Rule, or WebACL) using an action other than INSERT or DELETE.
You tried to create a WebACL with a DefaultAction Type other than ALLOW, BLOCK, or COUNT.
You tried to create a RateBasedRule with a RateKey value other than IP.
You tried to update a WebACL with a WafAction Type other than ALLOW, BLOCK, or COUNT.
You tried to update a ByteMatchSet with a FieldToMatch Type other than HEADER, METHOD, QUERY_STRING, URI, or BODY.
You tried to update a ByteMatchSet with a Field of HEADER but no value for Data.
Your request references an ARN that is malformed, or corresponds to a resource with which a web ACL cannot be associated.

HTTP Status Code: 400

WAFLimitsExceededException

The operation exceeds a resource limit, for example, the maximum number of WebACL objects that you can create for an AWS account. For more information, see AWS WAF Classic quotas in the AWS WAF Developer Guide.

HTTP Status Code: 400

WAFStaleDataException

The operation failed because you tried to create, update, or delete an object by using a change token that has already been used.

HTTP Status Code: 400