X-Git-Url: https://git.distorted.org.uk/~mdw/sgt/putty/blobdiff_plain/72be5b5ec697d1a93ed091721031b9979c6d9633..8ad3d7a26d9aa6b8a8d36d15abcab6996677ff94:/doc/faq.but diff --git a/doc/faq.but b/doc/faq.but index 8acd6364..2b6dc8c9 100644 --- a/doc/faq.but +++ b/doc/faq.but @@ -101,6 +101,41 @@ authentication, which is more flexible and more secure. See \k{pubkey} in the documentation for a full discussion of public key authentication. +\S{faq-hostkeys} Is there an option to turn off the annoying host +key prompts? + +No, there isn't. And there won't be. Even if you write it yourself +and send us the patch, we won't accept it. + +Those annoying host key prompts are the \e{whole point} of SSH. +Without them, all the cryptographic technology SSH uses to secure +your session is doing nothing more than making an attacker's job +slightly harder; instead of sitting between you and the server with +a packet sniffer, the attacker must actually subvert a router and +start modifying the packets going back and forth. But that's not all +that much harder than just sniffing; and without host key checking, +it will go completely undetected by client or server. + +Host key checking is your guarantee that the encryption you put on +your data at the client end is the \e{same} encryption taken off the +data at the server end; it's your guarantee that it hasn't been +removed and replaced somewhere on the way. Host key checking makes +the attacker's job \e{astronomically} hard, compared to packet +sniffing, and even compared to subverting a router. Instead of +applying a little intelligence and keeping an eye on Bugtraq, the +attacker must now perform a brute-force attack against at least one +military-strength cipher. That insignificant host key prompt really +does make \e{that} much difference. + +If you're having a specific problem with host key checking - perhaps +you want an automated batch job to make use of PSCP or Plink, and +the interactive host key prompt is hanging the batch process - then +the right way to fix it is to add the correct host key to the +Registry in advance. That way, you retain the \e{important} feature +of host key checking: the right key will be accepted and the wrong +ones will not. Adding an option to turn host key checking off +completely is the wrong solution and we will not do it. + \S{faq-server} Will you write an SSH server for the PuTTY suite, to go with the client? @@ -442,6 +477,28 @@ and you should report it (although it might be a bug in your SSH server instead); but it doesn't necessarily mean you've actually run out of memory. +\S{faq-bce} When I run full-colour applications, I see areas of +black space where colour ought to be. + +You almost certainly need to enable the \q{Use background colour to +erase screen} setting in the Terminal panel. Note that if you do +this in mid-session, it won't take effect until you reset the +terminal (see \k{faq-resetterm}). + +\S{faq-resetterm} When I change some terminal settings, nothing +happens. + +Some of the terminal options (notably Auto Wrap and +background-colour screen erase) actually represent the \e{default} +setting, rather than the currently active setting. The server can +send sequences that modify these options in mid-session, but when +the terminal is reset (by server action, or by you choosing \q{Reset +Terminal} from the System menu) the defaults are restored. + +If you want to change one of these options in the middle of a +session, you will find that the change does not immediately take +effect. It will only take effect once you reset the terminal. + \S{faq-altgr} I can't type characters that require the AltGr key. In PuTTY version 0.51, the AltGr key was broken. The bug has been