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Error 400 when trying to download a file
Hello, I'm using Dropbox for OTA. It worked for long time up until couple of weeks ago. Now, connection is established, folder list is downloaded, but when trying to download a file, I'm receivi...
Hello,
Here is the problematic request (the one acknowledged with error 400), captured locally just before submitted:
'list_folder' request:
POST /2/files/list_folder HTTP/1.1<CR><LF>
Content-Type: application/json<CR><LF>
Authorization: Bearer sl.Bwg31qNyvs2KjuANe6wfTrBJu2LBO7mrVltkFc9dSYg9VCVfg4NhKyPbZ4Es5QSy2BMHTlno5OBgiF14RAOtFCHpbyWuJ1T-EY5jxgKIbOhDv1Wrq4DwXJR6SUHabSP4AdAHwTM<CR><LF>
Host: api.dropboxapi.com<CR><LF>
Content-Length: 41<CR><LF>
<CR><LF>
{"path": "/ota_bundle_office","limit": 1}<CR><LF>
'list_folder' response:
{"entries": [{".tag": "file", "name": "20240221072512_CC3220SF.tar", "path_lower": "/ota_bundle_office/20240221072512_cc3220sf.tar", "path_display": "/ota_bundle_office/20240221072512_CC3220SF.tar", "id": "id:dIosUmeVHMoAAAAAAAABVA", "client_modified": "2024-02-21T05:31:31Z", "server_modified": "2024-02-21T05:31:31Z", "rev": "01611dda3b09665000000026de23b50", "size": 573440, "is_downloadable": true, "content_hash": "c31073c7b9ea0a3fa69ff61a6ab8d80e5b51d9fa4ef8eee49384cc5b64071406"}], "cursor": "AAGUl6koiJNa5jclgopptYqRLLcfflMtyH4JCF0vnMrlWQ51eowHqMHoXjqHlaDMXOrhfzWY3yBqNRuGqrAgeS2n-Yf9OlPbeL03QBJ9uw3s2sAm-dAMk9r5JiK8ypWoLwhrYUtVsesIJ_8wu9N1J00J_kZpWsHG1iiuws4AmBtggVPtTKBNtD8TIZMGwQ9z1RrZtbYuHmoMXZ_Vm8a8CRDYen9zNkZsMRHsMOCUkj0b9w", "has_more": false}0<LF><CR>
problematic request:
POST /2/files/get_temporary_link HTTP/1.1<CR><LF>
Content-Type: application/json<CR><LF>
Authorization: Bearer sl.Bwg31qNyvs2KjuANe6wfTrBJu2LBO7mrVltkFc9dSYg9VCVfg4NhKyPbZ4Es5QSy2BMHTlno5OBgiF14RAOtFCHpbyWuJ1T-EY5jxgKIbOhDv1Wrq4DwXJR6SUHabSP4AdAHwTM<CR><LF>
Host: api.dropboxapi.com<CR><LF>
Content-Length: 58<CR><LF>
<CR><LF>
{"path": "/ota_bundle_office/20240221072512_CC3220SF.tar"}<CR><LF>
error 400 response:
<!DOCTYPE html><LF>
<html><LF>
<head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><LF>
<meta name="viewport" content="width=device-width, initial-scale=1" /><LF>
<title>Dropbox - 400</title><LF>
<link href="https://cfl.dropboxstatic.com/static/metaserver/static/css/error.css" rel="stylesheet" type="text/css"/><LF>
<link rel="shortcut icon" href="https://cfl.dropboxstatic.com/static/images/favicon.ico"/><LF>
</head><LF>
<body><LF>
<div class="figure"><LF>
<img src="https://assets.dropbox.com/www/en-us/illustrations/spot/target-miss.svg" alt="Error: 400"/><LF>
</div><LF>
<div id="errorbox"><LF>
<h1>Error (400)</h1>Something went wrong. Don't worry, your files are still safe and the Dropbox team has been notified. Check out our <a href="https://status.dropbox.com">Status Page</a> to see if there is a known incident, our <a href="https://www.dropbox.com/help">Help Center</a> and <a href="https://forums.dropbox.com">forums</a> for help, or head back to <a href="https://www.dropbox.com/home">home</a>.<LF>
</div><LF>
<LF>
</body><LF>
</html><LF>
<LF><CR>
Can you please help identify the incompatible format part? Thanks
Greg-DB
Dropbox Community Moderator
Dropbox Community Moderatorsz3324 As Здравко said, the request appears correct. I tried replicating the request as shown here and it did not fail like that for me, so please check that that's exactly what you're actually sending.
Here is a capture of the request when redirected to AWS (API Gateway service). It looks perfectly correct:
(bdc789db-0418-470d-8cd0-c875d80b44b3) Method request headers: {Authorization=*******************************************************************************************************************************************CLnyJw, X-Forwarded-Proto=https, X-Forwarded-For=2.53.174.13, Host=d13k3bi9ke.execute-api.us-east-1.amazonaws.com, X-Forwarded-Port=443, X-Amzn-Trace-Id=Root=1-65e41272-37ecaf0e7538265a0082a13f, Content-Type=application/json}
(bdc789db-0418-470d-8cd0-c875d80b44b3) Method request body before transformations: {
"path": "/ota_bundle_office/20240221072512_CC3220SF.tar"
}Adding the fact that the request is perfectly decoded by other servers (I tried AWS and httpdump.app) to the fact that it worked perfectly with Dropbox.com up until couple of weeks ago, might show that a recent change that you made in your server is the root cause for this issue. I do not think that this is a format issue. Please advise. Thanks
- Greg-DB
That doesn't seem to be the raw request, and regardless it's not the request to the Dropbox servers directly, so unfortunately we can't use that to debug this.
Whatever the issue is, we'll need to be able to reproduce the issue to confirm what is going wrong and how to fix it. I replicated the request you shared earlier, but that did not reproduce the issue, so it does not seem that that is a correct representation of the request being made. It's important to make sure we're investigating the exact right requests; sometimes substituting in different servers can be misleading as different servers may support different protocols/versions/features. For example, different servers may support different versions of the HTTP protocol, like how the api.dropboxapi.com servers support both HTTP/1.1 and HTTP/2, and will prefer HTTP/2 when possible.
Have you been able to reproduce the issue outside of that particular embedded system? Please let us know how to reproduce the issue, e.g., using curl, so we can investigate.
Another thing to note is to make sure that the client is sending the exact full amount of data as specified in the 'Content-Length' request header. If the client doesn't send that amount of data, the server can respond with that error.
As I wrote above, this is an embedded system and I'm using a library of the chip vendor, Texas Instrument (TI). Hence, I do not have access to exact format of the HTTP request.
I can only direct the request to another server (as I did with AWS and httpdump.app) or ask you for a log from your server that shows the mismatch, which then I can share with TI and ask them to fix.
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