This is the new *CloudFormation Template Reference Guide*. Please update your bookmarks and links. For help getting started with CloudFormation, see the [AWS CloudFormation User Guide](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/Welcome.html).

# AWS::WAF::ByteMatchSet
<a name="aws-resource-waf-bytematchset"></a>

**Note**  
This is **AWS WAF Classic** documentation. For more information, see [AWS WAF Classic](https://docs.aws.amazon.com/waf/latest/developerguide/classic-waf-chapter.html) in the developer guide.  
**For the latest version of AWS WAF**, use the AWS WAFV2 API and see the [AWS WAF Developer Guide](https://docs.aws.amazon.com/waf/latest/developerguide/waf-chapter.html). With the latest version, AWS WAF has a single set of endpoints for regional and global use. 

The `AWS::WAF::ByteMatchSet` resource creates an AWS WAF`ByteMatchSet` that identifies a part of a web request that you want to inspect.

## Syntax
<a name="aws-resource-waf-bytematchset-syntax"></a>

To declare this entity in your CloudFormation template, use the following syntax:

### JSON
<a name="aws-resource-waf-bytematchset-syntax.json"></a>

```
{
  "Type" : "AWS::WAF::ByteMatchSet",
  "Properties" : {
      "[ByteMatchTuples](#cfn-waf-bytematchset-bytematchtuples)" : [ ByteMatchTuple, ... ],
      "[Name](#cfn-waf-bytematchset-name)" : String
    }
}
```

### YAML
<a name="aws-resource-waf-bytematchset-syntax.yaml"></a>

```
Type: AWS::WAF::ByteMatchSet
Properties:
  [ByteMatchTuples](#cfn-waf-bytematchset-bytematchtuples): 
    - ByteMatchTuple
  [Name](#cfn-waf-bytematchset-name): String
```

## Properties
<a name="aws-resource-waf-bytematchset-properties"></a>

`ByteMatchTuples`  <a name="cfn-waf-bytematchset-bytematchtuples"></a>
Specifies the bytes (typically a string that corresponds with ASCII characters) that you want AWS WAF to search for in web requests, the location in requests that you want AWS WAF to search, and other settings.  
*Required*: No  
*Type*: Array of [ByteMatchTuple](aws-properties-waf-bytematchset-bytematchtuple.md)  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`Name`  <a name="cfn-waf-bytematchset-name"></a>
The name of the `ByteMatchSet`. You can't change `Name` after you create a `ByteMatchSet`.  
*Required*: Yes  
*Type*: String  
*Pattern*: `.*\S.*`  
*Minimum*: `1`  
*Maximum*: `128`  
*Update requires*: [Replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

## Return values
<a name="aws-resource-waf-bytematchset-return-values"></a>

### Ref
<a name="aws-resource-waf-bytematchset-return-values-ref"></a>

When you pass the logical ID of this resource to the intrinsic `Ref` function, `Ref` returns the resource physical ID, such as 1234a1a-a1b1-12a1-abcd-a123b123456.

For more information about using the `Ref` function, see [https://docs.aws.amazon.com/AWSCloudFormation/latest/TemplateReference/intrinsic-function-reference-ref.html](https://docs.aws.amazon.com/AWSCloudFormation/latest/TemplateReference/intrinsic-function-reference-ref.html).

### Fn::GetAtt
<a name="aws-resource-waf-bytematchset-return-values-fn--getatt"></a>

## Examples
<a name="aws-resource-waf-bytematchset--examples"></a>



**Topics**
+ [HTTP Referers](#aws-resource-waf-bytematchset--examples--HTTP_Referers)
+ [Associate a ByteMatchSet with a Web ACL Rule](#aws-resource-waf-bytematchset--examples--Associate_a_ByteMatchSet_with_a_Web_ACL_Rule)
+ [Create a Web ACL](#aws-resource-waf-bytematchset--examples--Create_a_Web_ACL)

### HTTP Referers
<a name="aws-resource-waf-bytematchset--examples--HTTP_Referers"></a>

The following example defines a set of HTTP referers to match.

#### JSON
<a name="aws-resource-waf-bytematchset--examples--HTTP_Referers--json"></a>

```
"BadReferers": {
  "Type": "AWS::WAF::ByteMatchSet",
  "Properties": {
    "Name": "ByteMatch for matching bad HTTP referers",
    "ByteMatchTuples": [
      {
        "FieldToMatch" : {
          "Type": "HEADER",
          "Data": "referer"
        },
        "TargetString" : "badrefer1",
        "TextTransformation" : "NONE",
        "PositionalConstraint" : "CONTAINS"
      },
      {
        "FieldToMatch" : {
          "Type": "HEADER",
          "Data": "referer"
        },
        "TargetString" : "badrefer2",
        "TextTransformation" : "NONE",
        "PositionalConstraint" : "CONTAINS"
      }
    ]
  }
}
```

#### YAML
<a name="aws-resource-waf-bytematchset--examples--HTTP_Referers--yaml"></a>

```
BadReferers: 
  Type: "AWS::WAF::ByteMatchSet"
  Properties: 
    Name: "ByteMatch for matching bad HTTP referers"
    ByteMatchTuples: 
      - 
        FieldToMatch: 
          Type: "HEADER"
          Data: "referer"
        TargetString: "badrefer1"
        TextTransformation: "NONE"
        PositionalConstraint: "CONTAINS"
      - 
        FieldToMatch: 
          Type: "HEADER"
          Data: "referer"
        TargetString: "badrefer2"
        TextTransformation: "NONE"
        PositionalConstraint: "CONTAINS"
```

### Associate a ByteMatchSet with a Web ACL Rule
<a name="aws-resource-waf-bytematchset--examples--Associate_a_ByteMatchSet_with_a_Web_ACL_Rule"></a>

The following example associates the `BadReferers` byte match set with a web access control list (ACL) rule.

#### JSON
<a name="aws-resource-waf-bytematchset--examples--Associate_a_ByteMatchSet_with_a_Web_ACL_Rule--json"></a>

```
"BadReferersRule" : {
  "Type": "AWS::WAF::Rule",
  "Properties": {
    "Name": "BadReferersRule",
    "MetricName" : "BadReferersRule",
    "Predicates": [
      {
        "DataId" : {  "Ref" : "BadReferers" },
        "Negated" : false,
        "Type" : "ByteMatch"
      }
    ]
  }
}
```

#### YAML
<a name="aws-resource-waf-bytematchset--examples--Associate_a_ByteMatchSet_with_a_Web_ACL_Rule--yaml"></a>

```
BadReferersRule: 
  Type: "AWS::WAF::Rule"
  Properties: 
    Name: "BadReferersRule"
    MetricName: "BadReferersRule"
    Predicates: 
      - 
        DataId: 
          Ref: "BadReferers"
        Negated: false
        Type: "ByteMatch"
```

### Create a Web ACL
<a name="aws-resource-waf-bytematchset--examples--Create_a_Web_ACL"></a>

The following example associates the `BadReferersRule` rule with a web ACL. The web ACL allows all requests except for ones with referers that match the `BadReferersRule` rule.

#### JSON
<a name="aws-resource-waf-bytematchset--examples--Create_a_Web_ACL--json"></a>

```
"MyWebACL": {
  "Type": "AWS::WAF::WebACL",
  "Properties": {
    "Name": "WebACL to block IP addresses",
    "DefaultAction": {
      "Type": "ALLOW"
    },
    "MetricName" : "MyWebACL",
    "Rules": [
      {
        "Action" : {
          "Type" : "BLOCK"
        },
        "Priority" : 1,
        "RuleId" : { "Ref" : "BadReferersRule" }
      }
    ]
  }      
}
```

#### YAML
<a name="aws-resource-waf-bytematchset--examples--Create_a_Web_ACL--yaml"></a>

```
MyWebACL: 
  Type: "AWS::WAF::WebACL"
  Properties: 
    Name: "WebACL to block IP addresses"
    DefaultAction: 
      Type: "ALLOW"
    MetricName: "MyWebACL"
    Rules: 
      - 
        Action: 
          Type: "BLOCK"
        Priority: 1
        RuleId: 
          Ref: "BadReferersRule"
```

# AWS::WAF::ByteMatchSet ByteMatchTuple
<a name="aws-properties-waf-bytematchset-bytematchtuple"></a>

**Note**  
AWS WAF Classic support will end on September 30, 2025.   
This is **AWS WAF Classic** documentation. For more information, see [AWS WAF Classic](https://docs.aws.amazon.com/waf/latest/developerguide/classic-waf-chapter.html) in the developer guide.  
**For the latest version of AWS WAF**, use the AWS WAFV2 API and see the [AWS WAF Developer Guide](https://docs.aws.amazon.com/waf/latest/developerguide/waf-chapter.html). With the latest version, AWS WAF has a single set of endpoints for regional and global use. 

The bytes (typically a string that corresponds with ASCII characters) that you want AWS WAF to search for in web requests, the location in requests that you want AWS WAF to search, and other settings.

## Syntax
<a name="aws-properties-waf-bytematchset-bytematchtuple-syntax"></a>

To declare this entity in your CloudFormation template, use the following syntax:

### JSON
<a name="aws-properties-waf-bytematchset-bytematchtuple-syntax.json"></a>

```
{
  "[FieldToMatch](#cfn-waf-bytematchset-bytematchtuple-fieldtomatch)" : FieldToMatch,
  "[PositionalConstraint](#cfn-waf-bytematchset-bytematchtuple-positionalconstraint)" : String,
  "[TargetString](#cfn-waf-bytematchset-bytematchtuple-targetstring)" : String,
  "[TargetStringBase64](#cfn-waf-bytematchset-bytematchtuple-targetstringbase64)" : String,
  "[TextTransformation](#cfn-waf-bytematchset-bytematchtuple-texttransformation)" : String
}
```

### YAML
<a name="aws-properties-waf-bytematchset-bytematchtuple-syntax.yaml"></a>

```
  [FieldToMatch](#cfn-waf-bytematchset-bytematchtuple-fieldtomatch): 
    FieldToMatch
  [PositionalConstraint](#cfn-waf-bytematchset-bytematchtuple-positionalconstraint): String
  [TargetString](#cfn-waf-bytematchset-bytematchtuple-targetstring): 
    String
  [TargetStringBase64](#cfn-waf-bytematchset-bytematchtuple-targetstringbase64): 
    String
  [TextTransformation](#cfn-waf-bytematchset-bytematchtuple-texttransformation): String
```

## Properties
<a name="aws-properties-waf-bytematchset-bytematchtuple-properties"></a>

`FieldToMatch`  <a name="cfn-waf-bytematchset-bytematchtuple-fieldtomatch"></a>
The part of a web request that you want to inspect, such as a specified header or a query string.  
*Required*: Yes  
*Type*: [FieldToMatch](aws-properties-waf-bytematchset-fieldtomatch.md)  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`PositionalConstraint`  <a name="cfn-waf-bytematchset-bytematchtuple-positionalconstraint"></a>
Within the portion of a web request that you want to search (for example, in the query string, if any), specify where you want AWS WAF to search. Valid values include the following:  
 **CONTAINS**   
The specified part of the web request must include the value of `TargetString`, but the location doesn't matter.  
 **CONTAINS\$1WORD**   
The specified part of the web request must include the value of `TargetString`, and `TargetString` must contain only alphanumeric characters or underscore (A-Z, a-z, 0-9, or \$1). In addition, `TargetString` must be a word, which means one of the following:  
+ `TargetString` exactly matches the value of the specified part of the web request, such as the value of a header.
+ `TargetString` is at the beginning of the specified part of the web request and is followed by a character other than an alphanumeric character or underscore (\$1), for example, `BadBot;`.
+ `TargetString` is at the end of the specified part of the web request and is preceded by a character other than an alphanumeric character or underscore (\$1), for example, `;BadBot`.
+ `TargetString` is in the middle of the specified part of the web request and is preceded and followed by characters other than alphanumeric characters or underscore (\$1), for example, `-BadBot;`.
 **EXACTLY**   
The value of the specified part of the web request must exactly match the value of `TargetString`.  
 **STARTS\$1WITH**   
The value of `TargetString` must appear at the beginning of the specified part of the web request.  
 **ENDS\$1WITH**   
The value of `TargetString` must appear at the end of the specified part of the web request.  
*Required*: Yes  
*Type*: String  
*Allowed values*: `EXACTLY | STARTS_WITH | ENDS_WITH | CONTAINS | CONTAINS_WORD`  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`TargetString`  <a name="cfn-waf-bytematchset-bytematchtuple-targetstring"></a>
The value that you want AWS WAF to search for. AWS WAF searches for the specified string in the part of web requests that you specified in `FieldToMatch`. The maximum length of the value is 50 bytes.  
You must specify this property or the `TargetStringBase64` property.   
Valid values depend on the values that you specified for `FieldToMatch`:  
+ `HEADER`: The value that you want AWS WAF to search for in the request header that you specified in `FieldToMatch`, for example, the value of the `User-Agent` or `Referer` header.
+ `METHOD`: The HTTP method, which indicates the type of operation specified in the request. Amazon CloudFront supports the following methods: `DELETE`, `GET`, `HEAD`, `OPTIONS`, `PATCH`, `POST`, and `PUT`.
+ `QUERY_STRING`: The value that you want AWS WAF to search for in the query string, which is the part of a URL that appears after a `?` character.
+ `URI`: The value that you want AWS WAF to search for in the part of a URL that identifies a resource, for example, `/images/daily-ad.jpg`.
+ `BODY`: The part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form. The request body immediately follows the request headers. Note that only the first `8192` bytes of the request body are forwarded to AWS WAF for inspection. To allow or block requests based on the length of the body, you can create a size constraint set. 
+ `SINGLE_QUERY_ARG`: The parameter in the query string that you will inspect, such as *UserName* or *SalesRegion*. The maximum length for `SINGLE_QUERY_ARG` is 30 characters.
+ `ALL_QUERY_ARGS`: Similar to `SINGLE_QUERY_ARG`, but instead of inspecting a single parameter, AWS WAF inspects all parameters within the query string for the value or regex pattern that you specify in `TargetString`.
If `TargetString` includes alphabetic characters A-Z and a-z, note that the value is case sensitive.  
*Required*: Conditional  
*Type*: String  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`TargetStringBase64`  <a name="cfn-waf-bytematchset-bytematchtuple-targetstringbase64"></a>
The base64-encoded value that AWS WAF searches for. AWS CloudFormation sends this value to AWS WAF without encoding it.  
You must specify this property or the `TargetString` property.  
AWS WAF searches for this value in a specific part of web requests, which you define in the `FieldToMatch` property.  
Valid values depend on the Type value in the `FieldToMatch` property. For example, for a `METHOD` type, you must specify HTTP methods such as `DELETE, GET, HEAD, OPTIONS, PATCH, POST`, and `PUT`.   
*Required*: Conditional  
*Type*: String  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`TextTransformation`  <a name="cfn-waf-bytematchset-bytematchtuple-texttransformation"></a>
Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass AWS WAF. If you specify a transformation, AWS WAF performs the transformation on `FieldToMatch` before inspecting it for a match.  
You can only specify a single type of TextTransformation.  
 **CMD\$1LINE**   
When you're concerned that attackers are injecting an operating system command line command and using unusual formatting to disguise some or all of the command, use this option to perform the following transformations:  
+ Delete the following characters: \$1 " ' ^
+ Delete spaces before the following characters: / (
+ Replace the following characters with a space: , ;
+ Replace multiple spaces with one space
+ Convert uppercase letters (A-Z) to lowercase (a-z)
 **COMPRESS\$1WHITE\$1SPACE**   
Use this option to replace the following characters with a space character (decimal 32):  
+ \$1f, formfeed, decimal 12
+ \$1t, tab, decimal 9
+ \$1n, newline, decimal 10
+ \$1r, carriage return, decimal 13
+ \$1v, vertical tab, decimal 11
+ non-breaking space, decimal 160
`COMPRESS_WHITE_SPACE` also replaces multiple spaces with one space.  
 **HTML\$1ENTITY\$1DECODE**   
Use this option to replace HTML-encoded characters with unencoded characters. `HTML_ENTITY_DECODE` performs the following operations:  
+ Replaces `(ampersand)quot;` with `"`
+ Replaces `(ampersand)nbsp;` with a non-breaking space, decimal 160
+ Replaces `(ampersand)lt;` with a "less than" symbol
+ Replaces `(ampersand)gt;` with `>`
+ Replaces characters that are represented in hexadecimal format, `(ampersand)#xhhhh;`, with the corresponding characters
+ Replaces characters that are represented in decimal format, `(ampersand)#nnnn;`, with the corresponding characters
 **LOWERCASE**   
Use this option to convert uppercase letters (A-Z) to lowercase (a-z).  
 **URL\$1DECODE**   
Use this option to decode a URL-encoded value.  
 **NONE**   
Specify `NONE` if you don't want to perform any text transformations.  
*Required*: Yes  
*Type*: String  
*Allowed values*: `NONE | COMPRESS_WHITE_SPACE | HTML_ENTITY_DECODE | LOWERCASE | CMD_LINE | URL_DECODE`  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

# AWS::WAF::ByteMatchSet FieldToMatch
<a name="aws-properties-waf-bytematchset-fieldtomatch"></a>

**Note**  
AWS WAF Classic support will end on September 30, 2025.   
This is **AWS WAF Classic** documentation. For more information, see [AWS WAF Classic](https://docs.aws.amazon.com/waf/latest/developerguide/classic-waf-chapter.html) in the developer guide.  
**For the latest version of AWS WAF**, use the AWS WAFV2 API and see the [AWS WAF Developer Guide](https://docs.aws.amazon.com/waf/latest/developerguide/waf-chapter.html). With the latest version, AWS WAF has a single set of endpoints for regional and global use. 

Specifies where in a web request to look for `TargetString`.

## Syntax
<a name="aws-properties-waf-bytematchset-fieldtomatch-syntax"></a>

To declare this entity in your CloudFormation template, use the following syntax:

### JSON
<a name="aws-properties-waf-bytematchset-fieldtomatch-syntax.json"></a>

```
{
  "[Data](#cfn-waf-bytematchset-fieldtomatch-data)" : String,
  "[Type](#cfn-waf-bytematchset-fieldtomatch-type)" : String
}
```

### YAML
<a name="aws-properties-waf-bytematchset-fieldtomatch-syntax.yaml"></a>

```
  [Data](#cfn-waf-bytematchset-fieldtomatch-data): String
  [Type](#cfn-waf-bytematchset-fieldtomatch-type): String
```

## Properties
<a name="aws-properties-waf-bytematchset-fieldtomatch-properties"></a>

`Data`  <a name="cfn-waf-bytematchset-fieldtomatch-data"></a>
When the value of `Type` is `HEADER`, enter the name of the header that you want AWS WAF to search, for example, `User-Agent` or `Referer`. The name of the header is not case sensitive.  
When the value of `Type` is `SINGLE_QUERY_ARG`, enter the name of the parameter that you want AWS WAF to search, for example, `UserName` or `SalesRegion`. The parameter name is not case sensitive.  
If the value of `Type` is any other value, omit `Data`.  
*Required*: No  
*Type*: String  
*Pattern*: `.*\S.*`  
*Minimum*: `1`  
*Maximum*: `128`  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`Type`  <a name="cfn-waf-bytematchset-fieldtomatch-type"></a>
The part of the web request that you want AWS WAF to search for a specified string. Parts of a request that you can search include the following:  
+ `HEADER`: A specified request header, for example, the value of the `User-Agent` or `Referer` header. If you choose `HEADER` for the type, specify the name of the header in `Data`.
+ `METHOD`: The HTTP method, which indicated the type of operation that the request is asking the origin to perform. Amazon CloudFront supports the following methods: `DELETE`, `GET`, `HEAD`, `OPTIONS`, `PATCH`, `POST`, and `PUT`.
+ `QUERY_STRING`: A query string, which is the part of a URL that appears after a `?` character, if any.
+ `URI`: The part of a web request that identifies a resource, for example, `/images/daily-ad.jpg`.
+ `BODY`: The part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form. The request body immediately follows the request headers. Note that only the first `8192` bytes of the request body are forwarded to AWS WAF for inspection. To allow or block requests based on the length of the body, you can create a size constraint set.
+ `SINGLE_QUERY_ARG`: The parameter in the query string that you will inspect, such as *UserName* or *SalesRegion*. The maximum length for `SINGLE_QUERY_ARG` is 30 characters.
+ `ALL_QUERY_ARGS`: Similar to `SINGLE_QUERY_ARG`, but rather than inspecting a single parameter, AWS WAF will inspect all parameters within the query for the value or regex pattern that you specify in `TargetString`.
*Required*: Yes  
*Type*: String  
*Allowed values*: `URI | QUERY_STRING | HEADER | METHOD | BODY | SINGLE_QUERY_ARG | ALL_QUERY_ARGS`  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)