Different ETag vs. OC-ETag handling in sync-client

[ghost]

Hi,

currently updating the nginx config for oC 8.1/8.2 in owncloud-archive/documentation#1320 and planned to remove the gzip off; statement in there as oC 8.1.x has introduced the OC-ETag header.

My question is if the client able to handle a different ETag without any issues?

If gzip off; is used the server replies with the following response:

HTTP/1.1 200 OK
Server: nginx
Date: Tue, 13 Oct 2015 11:34:25 GMT
Content-Type: text/plain;charset=UTF-8
Content-Length: 56896
Connection: keep-alive
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Pragma: no-cache
Content-Security-Policy: default-src 'self'; script-src 'self' 'unsafe-eval'; style-src 'self' 'unsafe-inline'; frame-src *; img-src *; font-src 'self' data:; media-src *; connect-src *
Set-Cookie: 525469084e7d1=jb310a2tnaiv1thrkmp0q29mh3; path=/; secure; HttpOnly
Last-Modified: Tue, 13 Oct 2015 11:33:53 GMT
ETag: "6ebe2886830227ff37107c5253f56ded"
Content-Disposition: attachment
OC-ETag: "6ebe2886830227ff37107c5253f56ded"
X-XSS-Protection: 1; mode=block
X-Frame-Options: SAMEORIGIN
X-Content-Type-Options: nosniff
X-Robots-Tag: none
Strict-Transport-Security: max-age=15768000

where a gzip on; is showing:

HTTP/1.1 200 OK
Server: nginx
Date: Tue, 13 Oct 2015 11:35:24 GMT
Content-Type: text/plain;charset=UTF-8
Connection: keep-alive
Vary: Accept-Encoding
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Pragma: no-cache
Content-Security-Policy: default-src 'self'; script-src 'self' 'unsafe-eval'; style-src 'self' 'unsafe-inline'; frame-src *; img-src *; font-src 'self' data:; media-src *; connect-src *
Set-Cookie: 525469084e7d1=mb7oc53fbs41nf4gqda46i6g03; path=/; secure; HttpOnly
Last-Modified: Tue, 13 Oct 2015 11:33:53 GMT
ETag: W/"6ebe2886830227ff37107c5253f56ded"
Content-Disposition: attachment
OC-ETag: "6ebe2886830227ff37107c5253f56ded"
X-XSS-Protection: 1; mode=block
X-Frame-Options: SAMEORIGIN
X-Content-Type-Options: nosniff
X-Robots-Tag: none
Strict-Transport-Security: max-age=15768000
Content-Encoding: gzip

Note the difference between:

ETag: "6ebe2886830227ff37107c5253f56ded"
OC-ETag: "6ebe2886830227ff37107c5253f56ded"

and

ETag: W/"6ebe2886830227ff37107c5253f56ded"
OC-ETag: "6ebe2886830227ff37107c5253f56ded"

The requests above where done with:

curl -I -sH 'Accept-encoding: gzip' --user test:test https://example.com/remote.php/webdav/test.txt

[ckamm]

@RealRancor The client will always prefer the OC-ETag header. It also logs a message if it's different from ETag. The header parsing already strips out a trailing "-gzip", it seems we might also want to strip the W/ prefix for weak etags...

[ghost]

@ckamm Great, thanks for the info. So i think its save to remove the gzip off; from the nginx config.

[guruz]

@RealRancor Thanks for the initiative.
But what about Android and iOS?

@rperezb

[ghost]

@guruz

Ahhh, good point. Havn't thought about the Apps.

[ckamm]

@RealRancor The client also supports weak etags now. :)

[ghost]

@ckamm Great, thanks.

@ckamm @guruz Do you know who could answer the question if the Android and iOS app are also supporting the OC-ETag header?

[guruz]

@rperezb @davitol @davivel might know..

[javiergonzper]

On iOS we are not using the "OC-Etag" we are just using the "ETag".
Should we start to use "OC-Etag"?

PD: @guruz thanks for remember the mobile apps 😉

[davivel]

@RealRancor , in Android the preference for "OC-Etag" and the removal of "-gzip" suffix will be introduced with the next release - hopefully in the middle of November. It's part of owncloud/android#1109

[ghost]

@davivel Great, thanks for the info.

@javiergonzper I think it makes sense. A lot of serves configs out there will strip the ETag away or modify it so the "normal" ETag is not always reliable. Thats why oC 8.1 has introduced this new OC-ETag header.

So for know i keep the gzip off in the nginx config.