document DSA use of ssh-keygen

1 files changed, 39 insertions, 6 deletions

diff --git a/usr.bin/ssh/ssh-keygen.1 b/usr.bin/ssh/ssh-keygen.1
index 59c73cca741..8a40dee9b62 100644
--- a/usr.bin/ssh/ssh-keygen.1
+++ b/usr.bin/ssh/ssh-keygen.1
@@ -9,7 +9,7 @@
 .\"
 .\" Created: Sat Apr 22 23:55:14 1995 ylo
 .\"
-.\" $Id: ssh-keygen.1,v 1.14 2000/04/26 21:55:04 deraadt Exp $
+.\" $Id: ssh-keygen.1,v 1.15 2000/05/02 23:33:46 deraadt Exp $
 .\"
 .Dd September 25, 1999
 .Dt SSH-KEYGEN 1
@@ -19,7 +19,7 @@
 .Nd authentication key generation
 .Sh SYNOPSIS
 .Nm ssh-keygen
-.Op Fl q
+.Op Fl dq
 .Op Fl b Ar bits
 .Op Fl N Ar new_passphrase
 .Op Fl C Ar comment
@@ -43,11 +43,21 @@
 .Nm
 generates and manages authentication keys for
 .Xr ssh 1 .
+.Nm
+defaults to generating an RSA key for use by protocols 1.3 and 1.5;
+specifying the
+.Fl d
+flag will create a DSA key instead for use by protocol 2.0.
+.Pp
 Normally each user wishing to use SSH
-with RSA authentication runs this once to create the authentication
+with RSA or DSA authentication runs this once to create the authentication
 key in
-.Pa $HOME/.ssh/identity .
-Additionally, the system administrator may use this to generate host keys.
+.Pa $HOME/.ssh/identity
+or
+.Pa $HOME/.ssh/id_dsa .
+Additionally, the system administrator may use this to generate host keys,
+as seen in
+.Pa /etc/rc .
 .Pp
 Normally this program generates the key and asks for a file in which
 to store the private key.
@@ -71,7 +81,7 @@ If the passphrase is
 lost or forgotten, you will have to generate a new key and copy the
 corresponding public key to other machines.
 .Pp
-There is also a comment field in the key file that is only for
+For RSA, there is also a comment field in the key file that is only for
 convenience to the user to help identify the key.
 The comment can tell what the key is for, or whatever is useful.
 The comment is initialized to
@@ -80,6 +90,9 @@ when the key is created, but can be changed using the
 .Fl c
 option.
 .Pp
+After a key is generated, instructions below detail where the keys
+should be placed to be activated.
+.Pp
 The options are as follows:
 .Bl -tag -width Ds
 .It Fl b Ar bits
@@ -130,6 +143,8 @@ used to encrypt the private part of this file using 3DES.
 This file is not automatically accessed by
 .Nm
 but it is offered as the default file for the private key.
+.Xr sshd 8
+will read this file when a login attempt is made.
 .It Pa $HOME/.ssh/identity.pub
 Contains the public key for authentication.
 The contents of this file should be added to
@@ -137,6 +152,24 @@ The contents of this file should be added to
 on all machines
 where you wish to log in using RSA authentication.
 There is no need to keep the contents of this file secret.
+.It Pa $HOME/.ssh/id_dsa
+Contains the DSA authentication identity of the user.
+This file should not be readable by anyone but the user.
+It is possible to
+specify a passphrase when generating the key; that passphrase will be
+used to encrypt the private part of this file using 3DES.
+This file is not automatically accessed by
+.Nm
+but it is offered as the default file for the private key.
+.Xr sshd 8
+will read this file when a login attempt is made.
+.It Pa $HOME/.ssh/id_dsa.pub
+Contains the public key for authentication.
+The contents of this file should be added to
+.Pa $HOME/.ssh/authorized_keys2
+on all machines
+where you wish to log in using DSA authentication.
+There is no need to keep the contents of this file secret.
 .Sh AUTHOR
 Tatu Ylonen <ylo@cs.hut.fi>
 .Pp