I use the Windows Azure Blob Storage to keep files there.
To download files i create urls with Shared Access Signature.
It works fine, but there is one problem.
Some files (blobs) have the header "Content-Type" set during upload and other no.
if a file has no Content-Type than on request to Azure the response will have the header Content-Type: application/octet-stream . This is exactly what i need, because in such case a browser will show "Download dialog" for a user.
But for files where this header was set on upload, it is returned and sometimes it makes a problem. For example, Content-Type: images/jpeg makes a browser to show this image, but not download it (does not show Download dialog)
So, my question is
is there a way on download with presigned url from WIndows Azure to force to use some specific response header?
I want it behave like there is no Content-Type saved for a file, even if it is saved
So, after some time browsing i finally found the documentation about it.
There are references.
https://nxt.engineering/en/blog/sas_token/
https://learn.microsoft.com/en-us/rest/api/storageservices/service-sas-examples
https://learn.microsoft.com/en-us/rest/api/storageservices/create-service-sas
For me it was needed to up the version of the API (i used the 2012 API version).
Also one useful note. It is very sensetive to a date format. The expiraton time must be in the format like "2021-11-16T04:25:00Z" .
I have added 2 new arguments
'rscd=file;%20attachment&rsct=binary&'.
and both of the must be in the signature string to sign on their correct places
So, my question is is there a way on download with presigned url from
WIndows Azure to force to use some specific response header? I want it
behave like there is no Content-Type saved for a file, even if it is
saved
Yes, you can override Content-Disposition response header in your SAS Token and the blob will be always downloaded regardless of it’s content type.
You can override this header to a value like attachment; filename=yourdesiredfilename and the blob will always be downloaded with yourdesiredfilename name.
Related
As the Google Drive API document said about downloading a file:
https://www.googleapis.com/drive/v3/files/FILEID?alt=media%26key=API_KEY
If we paste this link to Chrome or Safari It will start downloading.
But the problem is
The name is changed to FIELDID
The extension is gone
For example
I have file mywork.fbx I upload to google drive, and the FileID is ABCDEFG
Then I go to the link below.
https://www.googleapis.com/drive/v3/files/ABCDEFG?alt=media%26key=MYAPIKEY
I got the file that name is ABCDEFG without extension
It should be mywork.fbx or anyname.fbx not just ABCDEFG
Tried
add &download="mywork.fbx"
use PHP header('Content-Disposition: attachment; filename="mywork.fbx"'); filename is mywork.fbx but the bandwidth is also mine too It's not only Google Drive!!!
$file_url = 'https://www.googleapis.com/drive/v3/files/ABCDEFG?alt=media&key=KEY';
header('Content-Disposition: attachment; filename="mywork.fbx"');
readfile($file_url);
check articles in stack overflow but I can't found the right one
You want to download a file which is not Google Docs using the browser.
You want to download a file with the filename which has the filename and extension of the original file.
You are using the API key.
In this case, the file is publicly shared.
If my understanding is correct, how about this answer? In this answer, webContentLink is used as the endpoint. The official document says as follows.
webContentLink:
A link for downloading the content of the file in a browser using cookie based authentication. In cases where the content is shared publicly, the content can be downloaded without any credentials.
Modified endpoint:
Please try to access the following endpoint with your browser.
https://drive.google.com/uc?export=download&id={fileId}
When you use this, please set the file ID. In this case, the file is not Google Docs.
When it accesses to the above endpoint, the file with the filename can be retrieved.
Reference:
Files of Drive API
If I misunderstood your question and this was not the direction, I apologize.
Look at the originalFilename property of https://developers.google.com/drive/api/v3/reference/files. You can use that in a content disposition header, see https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Disposition
The requirement is to provide a friendly file name during pdf download, to our customers with whom we have shared the azure blob download urls(blobs without SAS token).I am working on this requirement using azure emulator in my local set up. I have set the content disposition property during upload of the file and am able to see the same in the blob properties(using storage explorer) after upload but it isn't returned in the response during download. Is this the expected behaviour?
I have already tried the following suggestion:
set the DefaultServiceVersion of blob service before setting containerAcl--have set it to 2017-11-09..but still the x-ms-version returned in the download response header shows 2009-09-19 and there is no content disposition returned in the response. Have checked the property in powershell too using Get-AzStorageServiceProperty -ServiceType Blob -Context $ctx
the defaultversion is set to 2017-11-09...
cases where content disposition works:
1.When i send x-ms-version in the request header, i am able to download the pdf with the name set in the content disposition parameter of the uploaded file.
2.While using SAS token too, the content disposition parameter is used and i am able to download the file with the desired name.
I need to get this working for anonymous request.
this is what i have as of now:(PHP):
$this->blobSvc = BlobRestProxy::createBlobService($this->connectionString);
$serviceProperties = $this->blobSvc->getServiceProperties();
$serviceProperties->getValue()->setDefaultServiceVersion('2017-11-09');
$this->blobSvc->setServiceProperties($serviceProperties->getValue());
the defaultserviceversion gets set correctly. But still x-ms-version is incorrect in the response and content disposition header isnt returned during download
azure Emulator seems to have the above issue. With an actual azure account , content disposition for anonymous request works as expected.Thanks for all help.
I am using webpack to bundle all my assets files so I get something like this.
bundle.7fb44c37b0db67437e35.js
vendor.495e9142a1f8334dcc8c.js
styles.bc5b7548c97362b683f5582818914909.css
I use chunkhash in the name so when browser caches something it doesnt cache again until hash has changed. For example if I change something in styles, bundle the files and deploy, only the hash from styles will change, others wont so browser will request from the server again just the styles file and the rest will use from memory cache.
In response header I also have Etag and Last-Modified and they change every time I deploy app for every file. Should I remove them from response? Can that confuse the browser to contact the server and see if files have changed even though hash is still the same?
Great question. This depends largely on how the back-end is implemented and how it calculates the header values. Are the files served from our server, or something else like s3? Are we using a CDN? Are we using a framework for our application server? Who calculates these headers, the web server or the application server?
For the purposes of this answer and to keep things simple let's assume we are using the popular server framework Express with no CDN or 3rd party hosting. Like most application servers, Express calculates ETag and Last-Modified based on the content of the file being served - not the name of the file.
The first time a browser requests one of our files, it will receive the the ETag and Last-Modified for the resource. The next time the same resource is requested the browser will send the cached ETag and Last-Modified headers to the server. The server then decides based on these headers whether the browser needs to download a new version of the resource or if the cached version is current. If the cached resource is current, the server responds with a 304 - Not Modified status code. The status code is the key to this whole caching system - it is how the browser decides if it should use the cached resource.
To generate the ETag header, Express passes a binary Buffer representation of the response body to the etag module which calculates a SHA-1 hash based on the contents of the Buffer (source: generating ETag header and source: generating hash). To generate the Last-Modified header, Express uses the file system's last modified time (see lastModified in docs).
When webpack builds a new bundle the file's binary will change even if the chunkhash is the same. This causes Express to output a different Etag and Last-Modified, which means it will not respond with a 304 the next time the resource is requested. Without the 304 status code, the browser will unnecessarily re-download the bundle.
Answer
I think the best thing to do here is disable ETag and Last-Modified headers for these assets and instead use the Expires or Cache-Control: max-age header set to a date far in the future (usually 1 year). This way the browser will only re-download a bundle if it is expired or if it simply does not exist in the cache.
Our application is entirely built on websockets. We don't do any HTTP request-reply. However, we are stuck with file download. If i receive file content via websockets can I wrote to local folder on user computer ?
If it makes a difference, we are only supporting Chrome so not issue if it doesn't work on other browsers.
Also, I know i can do this via HTTP. Trying to avoid it and stick to websockets since thats how the entire app is.
Thanks a lot in advance!
The solution depends on size of your file.
If size is less than about 50 MB, I would encode file's content to base64 string on the server and send this string to the client. Client should receive parts of the string, concat them to single result, and store. After receiving whole string, add link (tag <a>) to your page with attribute href set to "data:<data_type>;base64,<base64_encoded_file_content>". <data_type> is a mime type of your file, for example "text/html" or "image/png". Suggest file name by adding download attribute set to name of file (doesn't work for Chrome on OS X).
Unfortunately I have no solution for large files. Currently there is only FileEntry API that allows to write files with JS, but according to documentation it is supported only by Chrome v13+, learn more here https://developer.mozilla.org/en-US/docs/Web/API/FileEntry.
So I'm pretty new at all this. I am trying to reverse engineer a web application.
When I submit a form, it sends a POST with a request payload that looks something similar to this:
encoding=UTF8&zip=1&size=136240&html=DwQgIg_a_whole_lot_more_gibberish_not_worth_posting
Anyways, from inspecting the captured traffic from Chrome developer tools, I noticed it is encoded and sent as a zipped up html?
How would I go about reversing this to see what the content is actually being sent to the server?
What you want to do is this:
1) Get the name of the zip file
2) Get the path of the zip file (likely the root directory or the current path the form is at)
3) Generate the URL (http://site_name.com/path/to/folder/zip_file.zip)
4) Download it using a too such as wget (typing the URL into the browser may work too)
I used this technique to download all the files that get downloaded to the OTA updates on iOS devices (used burp suit to intercept the zip file name where the server was on my computer which my iDevice was connected to).
Please note: the name of the zip file you have given does not end in .zip. this may mean it doesn't have a extension; you may have to add .zip to the file manually; or it may have another ending such as .tar, .tar.gz etc.