===================================================================
RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/ssh/sshd.8,v
retrieving revision 1.48
retrieving revision 1.49
diff -u -r1.48 -r1.49
--- src/usr.bin/ssh/sshd.8	2000/05/03 22:19:29	1.48
+++ src/usr.bin/ssh/sshd.8	2000/05/06 17:45:37	1.49
@@ -9,7 +9,7 @@
 .\"
 .\" Created: Sat Apr 22 21:55:14 1995 ylo
 .\"
-.\" $Id: sshd.8,v 1.48 2000/05/03 22:19:29 markus Exp $
+.\" $Id: sshd.8,v 1.49 2000/05/06 17:45:37 markus Exp $
 .\"
 .Dd September 25, 1999
 .Dt SSHD 8
@@ -46,9 +46,14 @@
 The forked daemons handle
 key exchange, encryption, authentication, command execution,
 and data exchange.
-.Pp
+This implementation of
 .Nm
+supports both SSH protocol version 1 and 2 simultaneously.
+.Nm
 works as follows.
+.Pp
+.Ss SSH protocol version 1
+.Pp
 Each host has a host-specific RSA key
 (normally 1024 bits) used to identify the host.
 Additionally, when
@@ -59,7 +64,7 @@
 Whenever a client connects the daemon responds with its public
 host and server keys.
 The client compares the
-host key against its own database to verify that it has not changed.
+RSA host key against its own database to verify that it has not changed.
 The client then generates a 256 bit random number.
 It encrypts this
 random number using both the host key and the server key, and sends
@@ -97,6 +102,28 @@
 .Xr rsh 1
 into the machine).
 .Pp
+.Ss SSH protocol version 2
+.Pp
+Version 2 works similar:
+Each host has a host-specific DSA key used to identify the host.
+However, when the daemon starts, it does not generate a server key.
+Forward security is provided through a Diffie-Hellman key agreement.
+This key agreement results in a shared session key.
+The rest of the session is encrypted
+using a symmetric cipher, currently
+Blowfish, 3DES or CAST128 in CBC mode or Arcfour.
+The client selects the encryption algorithm
+to use from those offered by the server.
+Additionally, session integrity is provided
+through a crytographic message authentication code
+(hmac-sha1 or hmac-md5).
+.Pp
+Protocol version 2 provides a public key based
+user authentication method (DSAAuthentication)
+and conventional password authentication.
+.Pp
+.Ss Command execution and data forwarding
+.Pp
 If the client successfully authenticates itself, a dialog for
 preparing the session is entered.
 At this time the client may request
@@ -148,7 +175,7 @@
 this many seconds, the server disconnects and exits.
 A value of zero indicates no limit.
 .It Fl h Ar host_key_file
-Specifies the file from which the host key is read (default
+Specifies the file from which the RSA host key is read (default
 .Pa /etc/ssh_host_key ) .
 This option must be given if
 .Nm
@@ -280,6 +307,11 @@
 can be used as wildcards in the patterns.
 Only user names are valid, a numerical user ID isn't recognized.
 By default login is allowed regardless of the user name.
+.It Cm DSAAuthentication
+Specifies whether DSA authentication is allowed.
+The default is
+.Dq yes .
+Note that this option applies to protocol version 2 only.
 .It Cm GatewayPorts
 Specifies whether remote hosts are allowed to connect to ports
 forwarded for the client.
@@ -407,6 +439,7 @@
 Specifies whether password authentication is allowed.
 The default is
 .Dq yes .
+Note that this option applies to both protocol version 1 and 2.
 .It Cm PermitEmptyPasswords
 When password authentication is allowed, it specifies whether the
 server allows login to accounts with empty password strings.
@@ -488,6 +521,7 @@
 Specifies whether pure RSA authentication is allowed.
 The default is
 .Dq yes .
+Note that this option applies to protocol version 1 only.
 .It Cm ServerKeyBits
 Defines the number of bits in the server key.
 The minimum value is 512, and the default is 768.
@@ -701,7 +735,7 @@
 pattern, it is not accepted (by that line) even if it matched another
 pattern on the line.
 .Pp
-Bits, exponent, and modulus are taken directly from the host key; they
+Bits, exponent, and modulus are taken directly from the RSA host key; they
 can be obtained, e.g., from
 .Pa /etc/ssh_host_key.pub .
 The optional comment field continues to the end of the line, and is not used.