All Products
Search

This Product

    Object Storage Service:0002-00000416

    Document Center

    Object Storage Service:0002-00000416

    Last Updated:Mar 20, 2026

    Problem description

    X-Amz-Expires is missing from the presigned URL query string. OSS rejects the request because the expiration time is not specified.

    Causes

    When using Amazon S3-compatible Signature Version 4 to generate presigned URLs, X-Amz-Expires is a required query string parameter. If it is absent, OSS cannot determine when the URL expires and rejects the request.

    Examples

    The following request is missing X-Amz-Expires. The X-Amz-Date value is also malformed — 86400 is appended directly to the timestamp instead of appearing as a separate X-Amz-Expires parameter:

    GET /test.txt?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=LTAI****************/20221220/us-east-1/s3/aws4_request&X-Amz-Date=20221220T084818Z86400&X-Amz-SignedHeaders=host&X-Amz-Signature=ab2***st HTTP/1.0
Date: Tue, 20 Dec 2022 08:48:18 GMT
Host: oss-example.oss-cn-hangzhou.aliyuncs.com
x-oss-s3-compat: true

    The required signature parameters for a valid presigned request are:

    ParameterDescription
    X-Amz-AlgorithmSigning algorithm. For Signature Version 4, use AWS4-HMAC-SHA256.
    X-Amz-CredentialCredential scope, in the format <AccessKeyID>/<date>/<region>/s3/aws4_request.
    X-Amz-DateSigning timestamp in ISO 8601 format: YYYYMMDDTHHMMSSZ.
    X-Amz-ExpiresA UNIX timestamp that specifies the expiration time of the request.
    X-Amz-SignedHeadersHTTP headers included in the signature calculation.
    X-Amz-SignatureThe computed request signature.

    Solutions

    Add X-Amz-Expires as a separate query string parameter and correct the X-Amz-Date value so it contains only the ISO 8601 timestamp:

    GET /test.txt?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=LTAI****************/20221220/us-east-1/s3/aws4_request&X-Amz-Date=20221220T084818Z&X-Amz-Expires=86400&X-Amz-SignedHeaders=host&X-Amz-Signature=ab2s**** HTTP/1.0
Date: Tue, 20 Dec 2022 08:48:18 GMT
Host: oss-example.oss-cn-hangzhou.aliyuncs.com
x-oss-s3-compat: true

    To avoid manually constructing presigned URLs, use Amazon S3 SDKs, which handle all required parameters automatically. For setup instructions, see Use Amazon S3 SDKs to access OSS.