Request Syntax Request Parameters Response Syntax Response Elements Errors See Also

UpdateSizeConstraintSet

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.

Inserts or deletes SizeConstraint objects (filters) in a SizeConstraintSet. For each SizeConstraint object, you specify the following values:

Whether to insert or delete the object from the array. If you want to change a SizeConstraintSetUpdate object, you delete the existing object and add a new one.
The part of a web request that you want AWS WAF to evaluate, such as the length of a query string or the length of the User-Agent header.
Whether to perform any transformations on the request, such as converting it to lowercase, before checking its length. Note that transformations of the request body are not supported because the AWS resource forwards only the first 8192 bytes of your request to AWS WAF.

You can only specify a single type of TextTransformation.
A ComparisonOperator used for evaluating the selected part of the request against the specified Size, such as equals, greater than, less than, and so on.
The length, in bytes, that you want AWS WAF to watch for in selected part of the request. The length is computed after applying the transformation.

For example, you can add a SizeConstraintSetUpdate object that matches web requests in which the length of the User-Agent header is greater than 100 bytes. You can then configure AWS WAF to block those requests.

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

Create a SizeConstraintSet. For more information, see CreateSizeConstraintSet.
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",
   "SizeConstraintSetId": "string",
   "Updates": [ 
      { 
         "Action": "string",
         "SizeConstraint": { 
            "ComparisonOperator": "string",
            "FieldToMatch": { 
               "Data": "string",
               "Type": "string"
            },
            "Size": number,
            "TextTransformation": "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

SizeConstraintSetId

The SizeConstraintSetId of the SizeConstraintSet that you want to update. SizeConstraintSetId is returned by CreateSizeConstraintSet and by ListSizeConstraintSets.

Type: String

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

Pattern: .*\S.*

Required: Yes

Updates

An array of SizeConstraintSetUpdate objects that you want to insert into or delete from a SizeConstraintSet. For more information, see the applicable data types:

SizeConstraintSetUpdate: Contains Action and SizeConstraint
SizeConstraint: Contains FieldToMatch, TextTransformation, ComparisonOperator, and Size
FieldToMatch: Contains Data and Type

Type: Array of SizeConstraintSetUpdate objects

Array Members: Minimum number of 1 item.

Required: Yes

Response Syntax


{
   "ChangeToken": "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 UpdateSizeConstraintSet 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.*

Errors

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

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

WAFInvalidOperationException

The operation failed because there was nothing to do. For example:

You tried to remove a Rule from a WebACL, but the Rule isn't in the specified WebACL.
You tried to remove an IP address from an IPSet, but the IP address isn't in the specified IPSet.
You tried to remove a ByteMatchTuple from a ByteMatchSet, but the ByteMatchTuple isn't in the specified WebACL.
You tried to add a Rule to a WebACL, but the Rule already exists in the specified WebACL.
You tried to add a ByteMatchTuple to a ByteMatchSet, but the ByteMatchTuple already exists in the specified WebACL.

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

WAFNonexistentContainerException

The operation failed because you tried to add an object to or delete an object from another object that doesn't exist. For example:

You tried to add a Rule to or delete a Rule from a WebACL that doesn't exist.
You tried to add a ByteMatchSet to or delete a ByteMatchSet from a Rule that doesn't exist.
You tried to add an IP address to or delete an IP address from an IPSet that doesn't exist.
You tried to add a ByteMatchTuple to or delete a ByteMatchTuple from a ByteMatchSet that doesn't exist.

HTTP Status Code: 400

WAFNonexistentItemException

The operation failed because the referenced object doesn't exist.

HTTP Status Code: 400

WAFReferencedItemException

The operation failed because you tried to delete an object that is still in use. For example:

You tried to delete a ByteMatchSet that is still referenced by a Rule.
You tried to delete a Rule that is still referenced by a WebACL.

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