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[ aws . waf ]

create-byte-match-set

Description

Creates a ByteMatchSet . You then use update-byte-match-set to identify the part of a web request that you want AWS WAF to inspect, such as the values of the User-Agent header or the query string. For example, you can create a ByteMatchSet that matches any requests with User-Agent headers that contain the string BadBot . You can then configure AWS WAF to reject those requests.

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

  • Use get-change-token to get the change token that you provide in the change-token parameter of a create-byte-match-set request.
  • Submit a create-byte-match-set request.
  • Use get-change-token to get the change token that you provide in the change-token parameter of an update-byte-match-set request.
  • Submit an update-byte-match-set request to specify the part of the request that you want AWS WAF to inspect (for example, the header or the URI) 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 .

See also: AWS API Documentation

Synopsis

  create-byte-match-set
--name <value>
--change-token <value>
[--cli-input-json <value>]
[--generate-cli-skeleton <value>]

Options

--name (string)

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

--change-token (string)

The value returned by the most recent call to get-change-token .

--cli-input-json (string) Performs service operation based on the JSON string provided. The JSON string follows the format provided by --generate-cli-skeleton. If other arguments are provided on the command line, the CLI values will override the JSON-provided values.

--generate-cli-skeleton (string) Prints a JSON skeleton to standard output without sending an API request. If provided with no value or the value input, prints a sample input JSON that can be used as an argument for --cli-input-json. If provided with the value output, it validates the command inputs and returns a sample output JSON for that command.

Output

ByteMatchSet -> (structure)

A ByteMatchSet that contains no ByteMatchTuple objects.

ByteMatchSetId -> (string)

The ByteMatchSetId for a ByteMatchSet . You use ByteMatchSetId to get information about a ByteMatchSet (see get-byte-match-set ), update a ByteMatchSet (see update-byte-match-set ), insert a ByteMatchSet into a Rule or delete one from a Rule (see update-rule ), and delete a ByteMatchSet from AWS WAF (see delete-byte-match-set ).

ByteMatchSetId is returned by create-byte-match-set and by list-byte-match-sets .

Name -> (string)

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

ByteMatchTuples -> (list)

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.

(structure)

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.

FieldToMatch -> (structure)

The part of a web request that you want AWS WAF to search, such as a specified header or a query string. For more information, see FieldToMatch .

Type -> (string)

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. For more information, see create-size-constraint-set .

Data -> (string)

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 . If the value of Type is any other value, omit Data .

The name of the header is not case sensitive.

TargetString -> (blob)

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.

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. 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. For more information, see create-size-constraint-set .

If TargetString includes alphabetic characters A-Z and a-z, note that the value is case sensitive.

If you're using the AWS WAF API

Specify a base64-encoded version of the value. The maximum length of the value before you base64-encode it is 50 bytes.

For example, suppose the value of Type is HEADER and the value of Data is User-Agent . If you want to search the User-Agent header for the value BadBot , you base64-encode BadBot using MIME base64 encoding and include the resulting value, QmFkQm90 , in the value of TargetString .

If you're using the AWS CLI or one of the AWS SDKs

The value that you want AWS WAF to search for. The SDK automatically base64 encodes the value.

TextTransformation -> (string)

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 TargetString before inspecting a request for a match.

CMD_LINE

When you're concerned that attackers are injecting an operating system commandline 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: " ' ^
  • 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_WHITE_SPACE

Use this option to replace the following characters with a space character (decimal 32):

  • f, formfeed, decimal 12
  • t, tab, decimal 9
  • n, newline, decimal 10
  • r, carriage return, decimal 13
  • v, vertical tab, decimal 11
  • non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

HTML_ENTITY_DECODE

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_DECODE

Use this option to decode a URL-encoded value.

NONE

Specify NONE if you don't want to perform any text transformations.

PositionalConstraint -> (string)

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_WORD

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 _). 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 (_), 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 (_), 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 (_), for example, -BadBot; .
EXACTLY

The value of the specified part of the web request must exactly match the value of TargetString .

STARTS_WITH

The value of TargetString must appear at the beginning of the specified part of the web request.

ENDS_WITH

The value of TargetString must appear at the end of the specified part of the web request.

ChangeToken -> (string)

The change-token that you used to submit the create-byte-match-set request. You can also use this value to query the status of the request. For more information, see get-change-token-status .