问@ Azure节点js生成SAS时身份验证失败。

EN

function getWriteSAS() {
    var blobService = storage.createBlobService();
    var container = 'container-name';
    var blobSAS = blobService.generateSharedAccessSignature(container, mCurrentRequest.param.blobName, getSharedAccessPolicy(10));
    urlForDownloading = blobService.host.primaryHost + container + '?' + blobSAS
    mCurrentResponse.status(200).send({"SASURI" : urlForDownloading})
}

function getSharedAccessPolicy(accessTimeInMinutes) {
    var startDate = new Date();
    var expiryDate = new Date(startDate);
    expiryDate.setMinutes(startDate.getMinutes() + accessTimeInMinutes);
    startDate.setMinutes(startDate.getMinutes() - accessTimeInMinutes);

    var sharedAccessPolicy = {
        AccessPolicy: {
            Permissions: storage.BlobUtilities.SharedAccessPermissions.WRITE,
            Start: startDate,
            Expiry: expiryDate
        },
    };
    return sharedAccessPolicy;
}

<Error>
<script/>
<Code>AuthenticationFailed</Code>
<Message>
Server failed to authenticate the request. Make sure the value of Authorization header is formed correctly including the signature. RequestId:2fab1644-0001-0087-7c99-c77b1a000000 Time:2016-06-16T06:36:14.5020064Z
</Message>
<AuthenticationErrorDetail>
Signature did not match. String to sign used was w 2016-06-16T06:24:52Z 2016-06-16T06:44:52Z /blob/irewardchart/$root 2015-04-05
</AuthenticationErrorDetail>
</Error>