[public-bpwg-comments] <none>

Comments: Since User-Agent has been the topic of some controversy in
comments, just wanted to voice support for the recommendation as
written here. While it is vital to preserve information about the
mobile device, this does not imply that User-Agent cannot be changed
if that information is otherwise preserved. Preserving the User-Agent
through a transforming proxy is misleading; the request is *not*
coming from a mobile device, but through a proxy. The origin server
should be aware of this.

Editorial: I think the Note here is a good one, but may be worth
expanding, since it is apparently already unclear to some how HTTPS
works here. The very purpose of HTTPS is to ensure that content is not
modified or read by third parties in transit, which means a
transforming proxy cannot jump into an HTTPS conversation between
mobile device and origin server. So there's not actually a question of
whether it's illegal or unethical -- it's simply not possible (unless
you have cracked SSL). It can only create a secure connection between
the mobile device and itself, and between itself and the origin
server. This is indeed a situation that the end user needs to

I suggest wording along these lines, take it or leave it as you see fit --

URIs which begin with the https scheme, when accessed, are secured
against eavesdropping and modification by third parties by the SSL
protocol. It is therefore not possible for a third-party transforming
proxy to participate directly in such a connection between mobile
device and origin server. Transforming proxies may still transform
content of https resources, but at best, it involves creating a
separate secure connection between device and proxy, and between proxy
and origin server. These communications are secure but the secured
content is of course visible to the transforming proxy. This may of
course be undesirable to an end user.

Therefore if a proxy rewrites https links, replacements links MUST at
least use the https scheme as well, and the proxy MUST use https to
communicate with the origin server. In addition the proxy MUST clearly
advise the user that the potentially sensitive contents of the
communication will be visible to the proxy, and must give the user an
option to opt out.

Received on Monday, 4 August 2008 16:06:14 UTC