diff --git a/share/doc/handbook/Makefile b/share/doc/handbook/Makefile index 0a7e06fb9726..369bc858d62a 100644 --- a/share/doc/handbook/Makefile +++ b/share/doc/handbook/Makefile @@ -1,4 +1,4 @@ -# $Id: Makefile,v 1.1 1995/09/08 19:34:26 jfieber Exp $ +# $Id: Makefile,v 1.2 1995/09/25 04:53:26 jfieber Exp $ SRCS= authors.sgml basics.sgml bibliography.sgml boothelp.sgml SRCS+= booting.sgml contrib.sgml crypt.sgml ctm.sgml current.sgml dialup.sgml @@ -6,7 +6,7 @@ SRCS+= diskless.sgml dma.sgml eresources.sgml esdi.sgml glossary.sgml SRCS+= handbook.sgml history.sgml hw.sgml install.sgml kerberos.sgml SRCS+= kerneldebug.sgml memoryuse.sgml mirrors.sgml nfs.sgml nutshell.sgml SRCS+= porting.sgml ports.sgml ppp.sgml relnotes.sgml scsi.sgml sections.sgml -SRCS+= slipc.sgml slips.sgml submitters.sgml sup.sgml +SRCS+= skey.sgml slipc.sgml slips.sgml submitters.sgml sup.sgml SRCS+= troubleshooting.sgml userppp.sgml .include diff --git a/share/doc/handbook/handbook.sgml b/share/doc/handbook/handbook.sgml index 02417be42fa2..b89298c6f970 100644 --- a/share/doc/handbook/handbook.sgml +++ b/share/doc/handbook/handbook.sgml @@ -1,4 +1,4 @@ - + . Users, groups and security &crypt; - * S/Key + &skey; &kerberos; * Firewalls diff --git a/share/doc/handbook/sections.sgml b/share/doc/handbook/sections.sgml index 268fc5b0bdcd..66c25a3c9e3d 100644 --- a/share/doc/handbook/sections.sgml +++ b/share/doc/handbook/sections.sgml @@ -1,4 +1,4 @@ - + @@ -32,6 +32,7 @@ + diff --git a/share/doc/handbook/skey.sgml b/share/doc/handbook/skey.sgml new file mode 100644 index 000000000000..7d1286266aef --- /dev/null +++ b/share/doc/handbook/skey.sgml @@ -0,0 +1,302 @@ + + + + +S/Key + +

Contributed by &a.wollman;25 September 1995. + +

S/Key is a one-time password scheme based on a one-way hash function +(in our version, this is MD4 for compatibility; other versions have +used MD5 and DES-MAC). S/Key has been a standard part of all FreeBSD +distributions since version 1.1.5, and is also implemented on a large +and growing number of other systems. S/Key is a registered trademark +of Bell Communications Research, Inc. + + +

There are three different sorts of passwords which we will talk about +in the discussion below. The first is your usual UNIX-style or Kerberos +password; we'll call this a ``UNIX password''. The second sort is the +one-time password which is generated by the S/Key `The secret password does not necessarily have anything to do with your +UNIX password (while they can be the same, this is not recommended). +While UNIX passwords are limited to eight characters in length, your +S/Key secret password can be as long as you like; I use seven-word +phrases. In general, the S/Key system operates completely +independently of the UNIX password system. + +

There are in addition two other sorts of data involved in the S/Key +system; one is called the ``seed'' or (confusingly) ``key'', and +consists of two letters and five digits, and the other is the +``iteration count'' and is a number between 100 and 1. S/Key +constructs a one-time password from these components by concatenating +the seed and the secret password, then applying a one-way hash (the +RSA Data Security, Inc., MD4 secure hash function) iteration-count +times, and turning the result into six short English words. The +`There are four programs involved in the S/Key system which we will +discuss below. The `/etc/skeykeys file and +prints out the invoking user's current iteration count and seed. +Finally, the `There are four different sorts of operations we will cover. The first +is using the `Secure connection initialization + +

To initialize S/Key, change your password, or change your seed while +logged in over a secure connection (e.g., on the console of a machine), +use the ` +$ keyinit +Updating wollman: ) these will not appear if you +Old key: ha73895 ) have not used S/Key before +Reminder - Only use this method if you are directly connected. +If you are using telnet or rlogin exit with no password and use keyinit -s. +Enter secret password: ) I typed my pass phrase here +Again secret password: ) I typed it again + +ID wollman s/key is 99 ha73896 ) discussed below +SAG HAS FONT GOUT FATE BOOM ) + + +

There is a lot of information here. At the `Enter secret password:' +prompt, you should enter some password or phrase (I use phrases of +minimum seven words) which will be needed to generate login keys. The +line starting `ID' gives the parameters of your particular S/Key +instance: your login name, the iteration count, and seed. When +logging in with S/Key, the system will remember these parameters and +present them back to you so you don't have to remember them. The last +line gives the particular one-time password which corresponds to those +parameters and your secret password; if you were to re-login +immediately, this one-time password is the one you would use. + +Insecure connection initialization + +

To initialize S/Key or change your password or seed over an insecure +connection, you will need to already have a secure connection to some +place where you can run the ` +$ keyinit -s +Updating wollman: +Old key: kh94741 +Reminder you need the 6 english words from the skey command. +Enter sequence count from 1 to 9999: 100 ) I typed this +Enter new key [default kh94742]: +s/key 100 kh94742 + + +To accept the default seed (which the `keyinit' program confusingly +calls a `key'), press return. Then move over to your secure +connection or S/Key desk accessory, and give it the same parameters: + + +$ key 100 kh94742 +Reminder - Do not use this program while logged in via telnet or rlogin. +Enter secret password: ) I typed my secret password +HULL NAY YANG TREE TOUT VETO + + +Now switch back over to the insecure connection, and copy the one-time +password generated by ` +s/key access password: HULL NAY YANG TREE TOUT VETO + +ID wollman s/key is 100 kh94742 +HULL NAY YANG TREE TOUT VETO + + +The rest of the description from the previous section applies here as +well. + +Diversion: a login prompt + +

Before explaining how to generate one-time passwords, we should go +over an S/Key login prompt: + + +$ telnet himalia +Trying 18.26.0.186... +Connected to himalia.lcs.mit.edu. +Escape character is '^]'. +s/key 92 hi52030 +Password: + + +>Note that, before prompting for a password, the login program +prints out the iteration number and seed which you will need in order +to generate the appropriate key. You will also find a useful feature +(not shown here): if you press return at the password prompt, the +login program will turn echo on, so you can see what you are typing. +This can be extremely useful if you are attempting to type in an S/Key +by hand, such as from a printout. + +

If this machine were configured to disallow UNIX passwords over a +connection from my machine, the prompt would have also included the +annotation `(s/key required)', indicating that only S/Key one-time +passwords will be accepted. + +Generating a single one-time password + +

Now, to generate the one-time password needed to answer this login +prompt, we use a trusted machine and the ` +$ key 92 hi52030 ) pasted from previous section +Reminder - Do not use this program while logged in via telnet or rlogin. +Enter secret password: ) I typed my secret password +ADEN BED WOLF HAW HOT STUN + + +And in the other window: + + +s/key 92 hi52030 ) from previous section +Password: + (turning echo on) +Password:ADEN BED WOLF HAW HOT STUN +Last login: Wed Jun 28 15:31:00 from halloran-eldar.l +[etc.] + + +This is the easiest mechanism Generating multiple one-time passwords + +

Sometimes we have to go places where no trusted machines or +connections are available. In this case, it is possible to use the +` +$ key -n 25 57 zz99999 +Reminder - Do not use this program while logged in via telnet or rlogin. +Enter secret password: +33: WALT THY MALI DARN NIT HEAD +34: ASK RICE BEAU GINA DOUR STAG +[...] +56: AMOS BOWL LUG FAT CAIN INCH +57: GROW HAYS TUN DISH CAR BALM + + +The `Restricting use of UNIX passwords + +

The configuration file /etc/skey.access can be used to +configure restrictions on the use of UNIX passwords based on the host +name, user name, terminal port, or IP address of a login session. The +complete format of the file is documented in the If there is no /etc/skey.access file (which is the default +state as FreeBSD is shipped), then all users will be allowed to use +UNIX passwords. If the file exists, however, then all users will be +required to use S/Key unless explicitly permitted to do otherwise by +configuration statements in the Here is a sample configuration file which illustrates the three most +common sorts of configuration statements: + + +permit internet 18.26.0.0 255.255.0.0 +permit user jrl +permit port ttyd0 + + +The first line (`The second line (`The third line (`