Fine Uploader getting “Policy expired” message sen

问题:

I recently implemented Fine Uploader and it's been mostly successful. A few users are however are not able to upload. They are all using modern browsers (IE10, FF and Chrome). One let me remotely access their machine and I was able to try it on both Chrome and FF.

I got the same error on both:

[10:45:28.330] "[FineUploader 3.8.0] Received response status 403 with body: <?xml version="1.0" encoding="UTF-8"?>
<Error><Code>AccessDenied</Code><Message>Invalid according to Policy: Policy expired.</Message><RequestId>--removed--</RequestId><HostId>--removed--</HostId></Error>"

Is it something with the timezone settings on their computer where it's generating an invalid policy?

回答1:

The timezone settings will have no effect as times are UTC. However, if the time on the user's computer is not accurate (say, off by 5 or more minutes), then the policy will be expired, according to Amazon.

Fine Uploader sets an expiration date to 5 minutes (again, in UTC). The date used is generated in the browser, so your client machine's time will be used. If the client machine's clock is slow by 5 or more minutes, the policy will be seen as expired when Amazon handles it.

I'm fairly sure that the issue is due to a significant drift on your customer's machine clock. If you verify this, I suggest you instruct them to keep system clock synced with a time server.

Update: A new feature was added to Fine Uploader 5.5 that allows you to overcome extreme clock drift on user machines/browsers. See the clock drift section on the S3 feature page for more information.