X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=blobdiff_plain;f=doc%2Fconfig.but;h=c8e68113895dfa211681d696ad08b4a58347be64;hb=fc77fa0b8b6bad71c6405500e0dfdf282abe0f42;hp=e56c069a1416535587b1cac94c4a8c2ad3ef37a2;hpb=de24c12e467b228f218cd5b14c30fdfd655bc487;p=PuTTY.git

diff --git a/doc/config.but b/doc/config.but
index e56c069a..c8e68113 100644
--- a/doc/config.but
+++ b/doc/config.but
@@ -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
 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.
 \cw{localhost} port 10022 in this example). Using the logical host
 name option, however, you can configure the second PuTTY to cache
@@ -2483,6 +2483,47 @@ when the SSH connection is idle, so they shouldn't cause the same
 problems.  The SSH-1 protocol, incidentally, has even weaker integrity
 protection than SSH-2 without rekeys.
 
+\H{config-ssh-hostkey} The Host Keys panel
+
+The Host Keys panel allows you to configure options related to SSH-2
+host key management.
+
+Host keys are used to prove the server's identity, and assure you that
+the server is not being spoofed (either by a man-in-the-middle attack
+or by completely replacing it on the network).
+
+This entire panel is only relevant to SSH protocol version 2; none of
+these settings affect SSH-1 at all.
+
+\S{config-ssh-hostkey-order} \ii{Host key type} selection
+
+\cfg{winhelp-topic}{ssh.hostkey.order}
+
+PuTTY supports a variety of SSH-2 host key types, and allows you to
+choose which one you prefer to use to identify the server.
+Configuration is similar to cipher selection (see
+\k{config-ssh-encryption}).
+
+PuTTY currently supports the following host key types:
+
+\b \q{Ed25519}: \i{Edwards-curve} \i{DSA} using a twisted Edwards
+curve with modulus \cw{2^255-19}.
+
+\b \q{ECDSA}: \i{elliptic curve} \i{DSA} using one of the
+NIST-standardised elliptic curves.
+
+\b \q{DSA}: straightforward \i{DSA} using modular exponentiation.
+
+\b \q{RSA}: the ordinary \i{RSA} algorithm.
+
+If PuTTY already has a host key stored for the server, it will prefer
+to use the one it already has. If not, it will choose an algorithm
+based on the preference order you specify in the configuration.
+
+If the first algorithm PuTTY finds is below the \q{warn below here}
+line, you will see a warning box when you make the connection, similar
+to that for cipher selection (see \k{config-ssh-encryption}).
+
 \S{config-ssh-kex-manual-hostkeys} \ii{Manually configuring host keys}
 
 \cfg{winhelp-topic}{ssh.kex.manualhostkeys}
@@ -2531,8 +2572,8 @@ 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
 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
-box, and the host key store in the Registry will be neither read
-\e{nor written}.
+box, and the \I{host key cache}host key store in the Registry will be
+neither read \e{nor written}, unless you explicitly do so.
 
 If the box is empty (as it usually is), then PuTTY's automated host
 key management will work as normal.