- From: Roy T. Fielding <fielding@kiwi.ics.uci.edu>
- Date: Wed, 17 Dec 1997 11:11:19 -0800
- To: John Franks <john@math.nwu.edu>
- Cc: http-wg%cuckoo.hpl.hp.com@hplb.hpl.hp.com
>The only reason this came up at this point was that because a hash >of the Date, L-M and Expires headers can be part of the response >there could be a problem for servers with no clock if a proxy added >a Date header. There is a simple answer to this which is that >proxies should not be allowed to add or change Date, L-M or Expires >headers. There are no known implementations which do so and no one >has suggested any reason it is necessary to do so. An HTTP/1.1 cache is required to change Date and Expires upon receipt of a 304 response containing updated values for those fields. This does impact non-shared caches, so you will need to add something to the effect of the digest should be removed if those fields are updated. The Apache proxy canonicalizes the response field-values of Date, Last-Modified, and Expires to the required HTTP-date format. I have no idea what effect this would have on entity-digest. If it caches the response, the cache will add Date and Content-Length if they are missing, but it won't normally cache the response if the request included Authorization (this would not be the case if we ever developed a personal, non-shared proxy). ....Roy
Received on Wednesday, 17 December 1997 11:34:19 UTC