.TH AUTH 2
.SH NAME
auth, srvauth, getchall, challreply, newns, authdial, passtokey, nvcsum \- network authentication
.SH SYNOPSIS
.nf
.PP
.ft L
#include <u.h>
#include <libc.h>
#include <auth.h>
.PP
.ft P
.B
char*	auth(int fd, char *dialstring)
.PP
.B
char*	srvauth(char *user)
.PP
.B
int	getchall(char *user, char chall[NETCHLEN]);
.PP
.B
int	challreply(int fd, char *user, char *response);
.PP
.B
char*	newns(char *user, char *nsfile)
.PP
.B
int	authdial(char *service)
.PP
.B
int	passtokey(char key[DESKEYLEN], char *password)
.PP
.B
uchar	nvcsum(void *mem, int len)
.SH DESCRIPTION
.I Auth
and
.I srvauth
authenticate connections for Plan 9 remote execution
using the
.I rexauth
protocol described in
.IR auth (6).
.I Auth
authenticates an outgoing network call.
.I Fd
is a file descriptor to the data channel of the network connection.
.I Auth
extracts from
.I dialstring
the name of the server being called.
.I Dialstring
should be the address passed to
.IR dial (2).
.I Auth
reads the user's name with
.IR getuser (2)
and uses
.B #c/crypt
for encrypting and decrypting
.I rexauth
messages.
.PP
.I Srvauth
authenticates the corresponding incoming call.
It copies the name of the user into
.IR user ,
which must be at least
.B NAMELEN
bytes long.
.PP
.I Getchall
and
.I challreply
authenticate an incoming network call for a service that does not
perform the usual Plan 9 authentication.
They use the
.I chal
protocol described in
.IR auth (6).
.I User
points to the local name of the user.
.I Getchall
reads a null-terminated textual challenge from the authentication server and copies it to
.IR chall .
It returns the open file descriptor to the authentication server,
or \-1 if it fails.
The challenge should be printed for the user to see,
and the user should use a Digital Pathways Securenet Key or
.I aux/netkey
(see
.IR passwd (1))
to generate the appropriate response.
.PP
.I Challreply
should be called with the user's response, which is also a null-terminated text string, and
the file descriptor returned from
.IR getchall .
It returns 0 if it succeeds,
or \-1 if the user was not authenticated.
.PP
.I Srvauth
and
.I challreply
set the process's user name and encryption key (see
.IR cons (3)).
.PP
.I Newns
builds a name space for
.IR user .
It opens the file
.I nsfile
.RB ( /lib/namespace
is used if
.I nsfile
is null),
copies the old environment, and erases the current name space,
sets the environment variables
.B user
and
.BR home ,
and interprets the commands in
.IR nsfile .
The format of
.I nsfile
is described in
.IR namespace (6).
.PP
.I Authdial
calls
.I service
on the local authentication server.
It returns a file descriptor to the open connection
or \-1 if it fails.
.PP
.I Passtokey
converts
.I password
into a DES key and stores the result in
.IR key .
It returns 0 if
.I password
could not be converted,
and 1 otherwise.
.PP
.I Nvcsum
computes a checksum for the 
.I len
byte array
.IR mem .
It is used to checksum keys stored in non-volatile RAM.
.SH FILES
.TF /lib/namespacexxx
.PD
.TP
.B #c/crypt
Encryption file used by
.IR auth .
.TP
.B /lib/namespace
Default name space specification file.
.SH DIAGNOSTICS
.IR Auth ,
.IR srvauth ,
and
.I newns
return a pointer to an error message upon failure, and 0 upon success.
.SH SEE ALSO
.IR passwd (1),
.IR auth (6),
.IR cons (3),
.IR dial (2)