tencent cloud

Overview

Tencent Cloud COS provides hotlink protection to help users avoid unnecessary losses caused by malicious programs' stealing public network traffic using resource URLs or stealing resources. We recommend that you configure the blocklist/allowlist in Hotlink Protection Settings on the console to ensure security protection.

Note：

• If a signature is carried in the access URL or headers, hotlink protection−based verification will not be performed.
• When configuring hotlink protection, you can add your domain to the allowlist for the multipart upload request of large files.

Directions

1. Log in to the COS console and click Bucket List in the left sidebar to enter the bucket list page.
2. Locate the bucket for which you want to set hotlink protection, and click its name to enter the bucket management page.
3. Choose Security Management > Hotlink Protection and click Edit.
   
4. Switch the status to Enabled, select a list type (blocklist or allowlist), enter the applicable domain names, and then click Save. The configuration items are described as follows:
   

• Blocklist: domain names on this list are not allowed to access the default access address of the bucket. 403 is returned if any domain name on the list accesses such address.

• Allowlist: domain names on this list are allowed to access the default access address of the bucket. 403 is returned if any domain name not on the list accesses such address.

• Empty referer: For an HTTP request, the header referer can be left empty (i.e., the HTTP request header has no referer field or the referer field is empty).

• Referer: You can enter up to 10 domain names (which can be used to represent all domain names with a particular prefix), with one domain name per line. Supported address formats include domain name, IP address, and the wildcard *; Examples are outlined below:

  • If www.example.com is specified, www.example.com/123, www.example.com.cn, and other addresses with the prefix of www.example.com will also be included in the list.

  • Domain names and IPs with ports are supported, such as www.example.com:8080 and 10.10.10.10:8080.

  • If *.example.com is specified, addresses such as a.b.example.com/123 and a.example.com are also included.

    Note：

    If accelerated access is implemented via a CDN endpoint domain name, CDN hotlink protection rules will be executed before COS hotlink protection rules.

Example

A user with the APPID of 1250000000 creates a bucket named examplebucket-1250000000 and places an image picture.jpg in the root directory. COS has generated the following default access address according to the rules:

examplebucket-1250000000.file.myqcloud.com/picture.jpg

User A owns a website:

www.example.com

and embeds the image into the homepage index.html.

Webmaster B manages a website:

www.fake.com

and wants to put this image on www.fake.com. But he doesn't want to pay for traffic costs. He creates a direct link to picture.jpg through the following address and places it into the homepage index.html on www.fake.com.

examplebucket-1250000000.file.myqcloud.com/picture.jpg

In such cases, to avoid losses for User A, we provide the following two methods of enabling hotlink protection.

Method 1

The blocklist method: Add *.fake.com to the blocklist and save.

Method 2

The allowlist method: Add *.example.com to the allowlist and save.

Before enabling hotlink protection

The image is displayed normally when http://www.example.com/index.html is accessed.
The image is also displayed normally when http://www.fake.com/index.html is accessed.

After enabling hotlink protection

The image is displayed normally when http://www.example.com/index.html is accessed.
The image cannot be displayed when http://www.fake.com/index.html is accessed.

About Wechat Mini Programs

1. For network requests using Wechat Mini Programs, the referer value is fixed as https://servicewechat.com/{appid}/{version}/page-frame.html.
2. If hotlink protection is enabled for your bucket, to allow Wechat Mini Programs to load COS images, add servicewechat.com to your hotlink allowlist on the COS console.