WAF / Client / update_byte_match_set

update_byte_match_set#

WAF.Client.update_byte_match_set(**kwargs)#

Note

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 ByteMatchTuple objects (filters) in a ByteMatchSet. For each ByteMatchTuple object, you specify the following values:

  • Whether to insert or delete the object from the array. If you want to change a ByteMatchSetUpdate object, you delete the existing object and add a new one.

  • The part of a web request that you want AWS WAF to inspect, such as a query string or the value of the User-Agent header.

  • The bytes (typically a string that corresponds with ASCII characters) that you want AWS WAF to look for. For more information, including how you specify the values for the AWS WAF API and the AWS CLI or SDKs, see TargetString in the ByteMatchTuple data type.

  • Where to look, such as at the beginning or the end of a query string.

  • Whether to perform any conversions on the request, such as converting it to lowercase, before inspecting it for the specified string.

For example, you can add a ByteMatchSetUpdate object that matches web requests in which User-Agent headers contain the string BadBot. You can then configure AWS WAF to block those requests.

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

  • Create a ByteMatchSet. For more information, see CreateByteMatchSet.

  • Use GetChangeToken to get the change token that you provide in the ChangeToken parameter of an UpdateByteMatchSet request.

  • Submit an UpdateByteMatchSet 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

Request Syntax

response = client.update_byte_match_set(
    ByteMatchSetId='string',
    ChangeToken='string',
    Updates=[
        {
            'Action': 'INSERT'|'DELETE',
            'ByteMatchTuple': {
                'FieldToMatch': {
                    'Type': 'URI'|'QUERY_STRING'|'HEADER'|'METHOD'|'BODY'|'SINGLE_QUERY_ARG'|'ALL_QUERY_ARGS',
                    'Data': 'string'
                },
                'TargetString': b'bytes',
                'TextTransformation': 'NONE'|'COMPRESS_WHITE_SPACE'|'HTML_ENTITY_DECODE'|'LOWERCASE'|'CMD_LINE'|'URL_DECODE',
                'PositionalConstraint': 'EXACTLY'|'STARTS_WITH'|'ENDS_WITH'|'CONTAINS'|'CONTAINS_WORD'
            }
        },
    ]
)
Parameters:

  • ByteMatchSetId (string) –

    [REQUIRED]

    The ByteMatchSetId of the ByteMatchSet that you want to update. ByteMatchSetId is returned by CreateByteMatchSet and by ListByteMatchSets.

  • ChangeToken (string) –

    [REQUIRED]

    The value returned by the most recent call to GetChangeToken.

  • Updates (list) –

    [REQUIRED]

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

    • ByteMatchSetUpdate: Contains Action and ByteMatchTuple

    • ByteMatchTuple: Contains FieldToMatch, PositionalConstraint, TargetString, and TextTransformation

    • FieldToMatch: Contains Data and Type

    • (dict) –

      Note

      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.

      In an UpdateByteMatchSet request, ByteMatchSetUpdate specifies whether to insert or delete a ByteMatchTuple and includes the settings for the ByteMatchTuple.

      • Action (string) – [REQUIRED]

        Specifies whether to insert or delete a ByteMatchTuple.

      • ByteMatchTuple (dict) – [REQUIRED]

        Information about the part of a web request that you want AWS WAF to inspect and the value that you want AWS WAF to search for. If you specify DELETE for the value of Action, the ByteMatchTuple values must exactly match the values in the ByteMatchTuple that you want to delete from the ByteMatchSet.

        • FieldToMatch (dict) – [REQUIRED]

          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) – [REQUIRED]

            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 CreateSizeConstraintSet.

            • 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.

          • 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. 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.

        • TargetString (bytes) – [REQUIRED]

          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 CreateSizeConstraintSet.

          • 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.

          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) – [REQUIRED]

          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_LINE

          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: “ ‘ ^

          • 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) – [REQUIRED]

          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.

Return type:

dict

Returns:

Response Syntax

{
    'ChangeToken': 'string'
}

Response Structure

  • (dict) –

    • ChangeToken (string) –

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

Exceptions

Examples

The following example deletes a ByteMatchTuple object (filters) in an byte match set with the ID exampleIDs3t-46da-4fdb-b8d5-abc321j569j5.

response = client.update_byte_match_set(
    ByteMatchSetId='exampleIDs3t-46da-4fdb-b8d5-abc321j569j5',
    ChangeToken='abcd12f2-46da-4fdb-b8d5-fbd4c466928f',
    Updates=[
        {
            'Action': 'DELETE',
            'ByteMatchTuple': {
                'FieldToMatch': {
                    'Data': 'referer',
                    'Type': 'HEADER',
                },
                'PositionalConstraint': 'CONTAINS',
                'TargetString': 'badrefer1',
                'TextTransformation': 'NONE',
            },
        },
    ],
)

print(response)

Expected Output:

{
    'ChangeToken': 'abcd12f2-46da-4fdb-b8d5-fbd4c466928f',
    'ResponseMetadata': {
        '...': '...',
    },
}