| 1 | Internet Explorer and SSL |
| 2 | Luke Ehresman <luke@squirrelmail.org> |
| 3 | ===================================== |
| 4 | |
| 5 | I've just spent the last few days trying to track down the now famous bug |
| 6 | with IE and SSL. The problem lies in the fact that PHP sends some no-cache |
| 7 | headers whenever a session is started. IE chokes when trying to download a |
| 8 | file that it can't cache over SSL. We use session management to store many |
| 9 | things, one being the key to decypher the password. |
| 10 | |
| 11 | Once we had figured out that it was sessions in PHP that was causing the |
| 12 | problem, we tried turning the session management off in the download script |
| 13 | in Squirrelmail. This introduced another problem for us because we NEEDED |
| 14 | sessions to decypher the key so we could log into the IMAP server and |
| 15 | download the attachment. |
| 16 | |
| 17 | Next we tried leaving the sessions turned off, but passed the key in through |
| 18 | a GET parameter. This worked, but is obviously not a very secure way of |
| 19 | handling things. |
| 20 | |
| 21 | Our quest continued for a good solution. Finally, I was browsing through |
| 22 | the source of PHP, I noticed the 2 headers it was sending were "Pragma" and |
| 23 | "Cache-Control". I had the crazy idea of defining these again after the |
| 24 | session had been started, and lo and behold, it worked! Below is the code |
| 25 | that made this work: |
| 26 | |
| 27 | session_start() |
| 28 | header("Pragma: "); |
| 29 | header("Cache-Control: cache"); |
| 30 | |
| 31 | With all the testing I have done, this works, and works very well for all |
| 32 | browsers. |