0002-00000220 - Object Storage Service - Alibaba Cloud Documentation Center

Problem description

The x-oss-signature field in the request is empty.

Causes

You initiate a request that uses the V4 signature. However, the x-oss-signature field in the request is empty.

Examples

The following code provides an example:

GET /oss.jpg?x-oss-signature-verion=OSS4-HMAC-SHA256&x-oss-credential=***&x-oss-expires=1141889120&x-oss-additional-headers=host&x-oss-signature= HTTP/1.1
Host: oss-example.oss-cn-hangzhou.aliyuncs.com
Date: Tue, 20 Dec 2022 08:48:18 GMT

The x-oss-signature field is required. It is used to specify the value of signature after calculation.

Solutions

You must specify the x-oss-signature-verion, x-oss-credential, x-oss-expires, and x-oss-signature fields in the request. You can specify the x-oss-additional-headers field as needed. The following code provides an example on how to specify the x-oss-credential field:

GET /oss.jpg?x-oss-signature-verion=OSS4-HMAC-SHA256&x-oss-credential=LTAI****************/20221220/cn-hangzhou/oss/aliyun_v4_request&x-oss-expires=1141889120&x-oss-additional-headers=host&x-oss-signature=8u**a3 HTTP/1.1
Host: oss-example.oss-cn-hangzhou.aliyuncs.com
Date: Tue, 20 Dec 2022 08:48:18 GMT

References

For information about how to use Alibaba Cloud SDKs to initiate a request that uses the V4 signature, see Overview.
Calculate the signature:
- For information about how to calculate the V4 signature, see Calculate V4 signature by using OSS SDK for Python.
- For information about how to specify the signature logic based on the V1 signature, see Overview.
If the server returns a response that contains the StringToSign parameter, you must check whether the value of the StringToSign parameter on the server is the same as the string before calculation.