nhyatt/putty-source
1
0
Fork 0
mirror of https://git.tartarus.org/simon/putty.git synced 2025-02-09 16:36:34 +00:00
Code Issues Projects Releases Wiki Activity

Document host key cross-certification.

Browse Source
This commit is contained in:
Jacob Nevins 2016-03-25 15:42:42 +00:00
parent d0d3c47a08
commit 28f67586f5
4 changed files with 37 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
doc/config.but
View File

@ -1747,7 +1747,7 @@ arbitrary port (say, \cw{localhost} port 10022) were forwarded to a
second machine's SSH port (say, \cw{foovax} port 22), and then second machine's SSH port (say, \cw{foovax} port 22), and then
started a second PuTTY connecting to the forwarded port. started a second PuTTY connecting to the forwarded port.
In normal usage, the second PuTTY will access the host key cache In normal usage, the second PuTTY will access the \i{host key cache}
under the host name and port it actually connected to (i.e. under the host name and port it actually connected to (i.e.
\cw{localhost} port 10022 in this example). Using the logical host \cw{localhost} port 10022 in this example). Using the logical host
name option, however, you can configure the second PuTTY to cache name option, however, you can configure the second PuTTY to cache
@ -2531,8 +2531,8 @@ If this box contains at least one host key or fingerprint when PuTTY
makes an SSH connection, then PuTTY's automated host key management is makes an SSH connection, then PuTTY's automated host key management is
completely bypassed: the connection will be permitted if and only if completely bypassed: the connection will be permitted if and only if
the host key presented by the server is one of the keys listed in this the host key presented by the server is one of the keys listed in this
box, and the host key store in the Registry will be neither read box, and the \I{host key cache}host key store in the Registry will be
\e{nor written}. neither read \e{nor written}, unless you explicitly do so.
If the box is empty (as it usually is), then PuTTY's automated host If the box is empty (as it usually is), then PuTTY's automated host
key management will work as normal. key management will work as normal.

16
doc/gs.but
View File

@ -77,13 +77,13 @@ server and it sends you a different host key from the one you were
expecting, PuTTY can warn you that the server may have been switched expecting, PuTTY can warn you that the server may have been switched
and that a spoofing attack might be in progress. and that a spoofing attack might be in progress.
PuTTY records the host key for each server you connect to, in the PuTTY \I{host key cache}records the host key for each server you
Windows \i{Registry}. Every time you connect to a server, it checks connect to, in the Windows \i{Registry}. Every time you connect to a
that the host key presented by the server is the same host key as it server, it checks that the host key presented by the server is the
was the last time you connected. If it is not, you will see a same host key as it was the last time you connected. If it is not,
warning, and you will have the chance to abandon your connection you will see a warning, and you will have the chance to abandon your
before you type any private information (such as a password) into connection before you type any private information (such as a
it. password) into it.
However, when you connect to a server you have not connected to However, when you connect to a server you have not connected to
before, PuTTY has no way of telling whether the host key is the before, PuTTY has no way of telling whether the host key is the
@ -97,7 +97,7 @@ network users are on the same side and spoofing attacks are
unlikely, so you might choose to trust the key without checking it. unlikely, so you might choose to trust the key without checking it.
If you are connecting across a hostile network (such as the If you are connecting across a hostile network (such as the
Internet), you should check with your system administrator, perhaps Internet), you should check with your system administrator, perhaps
by telephone or in person. (Some modern servers have more than one by telephone or in person. (Many servers have more than one
host key. If the system administrator sends you more than one host key. If the system administrator sends you more than one
\I{host key fingerprint}fingerprint, you should make sure the one \I{host key fingerprint}fingerprint, you should make sure the one
PuTTY shows you is on the list, but it doesn't matter which one it is.) PuTTY shows you is on the list, but it doesn't matter which one it is.)

3
doc/index.but
View File

@ -850,7 +850,8 @@ saved sessions from
\IM{logical host name} logical host name \IM{logical host name} logical host name
\IM{logical host name} host name, logical \IM{logical host name} host name, logical
\IM{logical host name} host key, caching policy
\IM{host key cache}{host key caching policy} host key caching policy
\IM{web browsers} web browser \IM{web browsers} web browser

26
doc/using.but
View File

@ -201,6 +201,28 @@ resets associated timers and counters). For more information about
repeat key exchanges, see \k{config-ssh-kex-rekey}. repeat key exchanges, see \k{config-ssh-kex-rekey}.
} }
\b \I{host key cache}Cache new host key type
\lcont{
Only available in SSH-2. This submenu appears only if the server has
host keys of a type that PuTTY doesn't already have cached, and so
won't use. Selecting a key here will allow PuTTY to use that key now
and in future: PuTTY will do key here will cause a fresh key-exchange
with the selected key, and immediately add that key to PuTTY's
permanent cache (relying on the host key used at the start of the
connection to cross-certify the new key). That key will be used for
the rest of the current session; it may not actually be used for
future sessions.
Normally, PuTTY will carry on using a host key it already knows, even
if the server offers key formats that PuTTY would otherwise prefer,
to avoid host key prompts. As a result, if you've been using a server
for some years, you may still be using an older key than a new user
would use, due to server upgrades in the meantime. The SSH protocol
unfortunately does not have organised facilities for host key migration
and rollover, but this allows you to manually upgrade.
}
\b \I{Break, SSH special command}Break \b \I{Break, SSH special command}Break
\lcont{ \lcont{
@ -912,7 +934,7 @@ authentication} box in the Auth panel of the PuTTY configuration box
\S2{using-cmdline-loghost} \i\c{-loghost}: specify a \i{logical host \S2{using-cmdline-loghost} \i\c{-loghost}: specify a \i{logical host
name} name}
This option overrides PuTTY's normal SSH host key caching policy by This option overrides PuTTY's normal SSH \i{host key caching policy} by
telling it the name of the host you expect your connection to end up telling it the name of the host you expect your connection to end up
at (in cases where this differs from the location PuTTY thinks it's at (in cases where this differs from the location PuTTY thinks it's
connecting to). It can be a plain host name, or a host name followed connecting to). It can be a plain host name, or a host name followed
@ -922,7 +944,7 @@ on this.
\S2{using-cmdline-hostkey} \i\c{-hostkey}: \I{manually configuring \S2{using-cmdline-hostkey} \i\c{-hostkey}: \I{manually configuring
host keys}manually specify an expected host key host keys}manually specify an expected host key
This option overrides PuTTY's normal SSH host key caching policy by This option overrides PuTTY's normal SSH \i{host key caching policy} by
telling it exactly what host key to expect, which can be useful if the telling it exactly what host key to expect, which can be useful if the
normal automatic host key store in the Registry is unavailable. The normal automatic host key store in the Registry is unavailable. The
argument to this option should be either a host key fingerprint, or an argument to this option should be either a host key fingerprint, or an