Help Center/ Content Delivery Network/ User Guide/ Custom Domain Name Configuration/ Access Control/ User-Agent ACL
Updated on 2024-11-26 GMT+08:00
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User-Agent ACL

You can configure a User-Agent ACL for your domain name to identify and filter visitors and enhance domain name security.

Background

You can filter requests to your domain name based on the User-Agent field.

  • Blacklist: Requests including fields in the blacklist cannot access the content and 403 will be returned.
  • Whitelist: Only requests including fields in the whitelist can access the content. Other requests will fail and 403 will be returned.

Precautions

  • This function is disabled by default.
  • Either a User-Agent blacklist or whitelist can be configured.

Procedure

  1. Log in to Huawei Cloud console. Choose Service List > Content Delivery & Edge Computing > Content Delivery Network.

    The CDN console is displayed.

  2. In the navigation pane, choose Domains.
  3. In the domain list, click the target domain name or click Configure in the Operation column.
  4. Click the Access Control tab.
  5. In the User-Agent ACL area, click Edit. The Configure User-Agent ACL dialog box is displayed.
    Figure 1 Configuring a User-Agent ACL

  1. Switch on Status to enable this configuration item.
  2. Select a type and enter rules.

    Parameter

    Description

    Type
    • Blacklist: Requests including fields in the blacklist cannot access the content. 403 is returned.
    • Whitelist: Only requests including fields in the whitelist can access the content. Other requests will fail and 403 will be returned.

    Include empty user agents

    An empty user agent indicates that the User-Agent field is left blank or is not included in an HTTP request. If this option is selected, such requests will also be accepted (whitelist) or rejected (blacklist).

    NOTE:

    The User-Agent field with value null is not an empty user agent.

    Rule
    • Enter letters, digits, spaces, and the following special characters: *.-_();,/'#!@$^&+=~?"[]{}\:%
      NOTE:

      For domain names with special configurations, (), {}, or [] must be both entered.

    • Only wildcard characters (*) can be used for regular expression matching. If no wildcard character is included, exact matching will be used.
    • Enter up to 100 characters for a rule.
    • Enter up to 50 rules, and enter them at separate rows.
  3. Click OK.
  4. (Optional) Disable the User-Agent ACL.
    • Switch off Status to disable the User-Agent ACL and clear all settings of the blacklist or whitelist. You need to set related parameters when enabling this function again.

Example

Assume that you have configured the following User-Agent blacklist for domain name www.example.com.

If User-Agent in the header of an HTTP request is one of the following:

User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; Trident/7.0; Touch; rv:11.0) like Gecko
user-agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/95.0.4638.54 Safari/537.36

Trident or Chrome is included in the blacklist, so 403 is returned.

Parent topic: Access Control