NAME
authdial, passtokey, nvcsum, readnvram, convT2M, convM2T, convTR2M, convM2TR, convA2M, convM2A, convPR2M, convM2PR, _asgetticket, _asrdresp – routines for communicating with authentication servers

SYNOPSIS

#include <u.h>
#include <libc.h>
#include <authsrv.h>

int     authdial(char *netroot, char *ad);

int     passtokey(char key[DESKEYLEN], char *password)

uchar nvcsum(void *mem, int len)

int     readnvram(Nvrsafe *nv, int flag);

int     convT2M(Ticket *t, char *msg, char *key)

void    convM2T(char *msg, Ticket *t, char *key)

int     convA2M(Authenticator *a, char *msg, char *key)

void    convM2A(char *msg, Authenticator *a, char *key)

int     convTR2M(Ticketreq *tr, char *msg)

void    convM2TR(char *msg, Ticketreq *tr)

int     convPR2M(Passwordreq *pr, char *msg, char *key)

void    convM2PR(char *msg, Passwordreq *pr, char *key)

int     _asgetticket(int fd, char *trbuf, char *tbuf);

int     _asrdresp(int fd, char *buf, int len);

DESCRIPTION
Authdial dials an authentication server over the network rooted at net, default /net. The authentication domain, ad, specifies which server to call. If ad is non–nil, the connection server cs (see ndb(8)) is queried for an entry which contains authdom=ad or dom=ad, the former having precedence, and which also contains an auth attribute. If it finds neither, it tries p9auth.ad in DNS as the authentication server. The string dialed is then netroot!server!ticket where server is the value of the auth attribute. If no entry is found, the error string is set to ``no authentication server found'' and –1 is returned. If authdom is nil, the string netroot!$auth!ticket is used to make the call.

Passtokey converts password into a DES key and stores the result in key. It returns 0 if password could not be converted, and 1 otherwise.

Readnvram reads authentication information into the structure:

struct Nvrsafe
{
char      machkey[DESKEYLEN];/* was file server's authid's des key */
uchar     machsum;
char      authkey[DESKEYLEN];/* authid's des key from password */
uchar     authsum;
/*
* file server config string of device holding full configuration;
* secstore key on non–file–servers.
*/
char      config[CONFIGLEN];
uchar     configsum;
char      authid[ANAMELEN];/* auth userid, e.g., bootes */
uchar     authidsum;
char      authdom[DOMLEN]; /* auth domain, e.g., cs.bell–labs.com */
uchar     authdomsum;
};

On Sparc, MIPS, and SGI machines this information is in non–volatile ram, accessible in the file #r/nvram. On x86s readnvram successively opens the following areas stopping with the first to succeed:

– the partition named by the $nvram environment variable (commonly set via plan9.ini(8))
– the partition #S/sdC0/nvram
a file called plan9.nvr in the partition #S/sdC0/9fat
the partition #S/sd00/nvram
a file called plan9.nvr in the partition #S/sd00/9fat
a file called plan9.nvr on a DOS floppy in drive 0
– a file called plan9.nvr on a DOS floppy in drive 1

The nvcsums of the fields machkey, authid, and authdom must match their respective checksum or that field is zeroed. If flag is NVwrite or at least one checksum fails and flag is NVwriteonerr, readnvram will prompt for new values on #c/cons and then write them back to the storage area. If flag is NVwritemem, readnvram will write the values in *nv back to the storage area.

ConvT2M, convA2M, convTR2M, and convPR2M convert tickets, authenticators, ticket requests, and password change request structures into transmittable messages. ConvM2T, convM2A, convM2TR, and convM2PR are used to convert them back. Key is used for encrypting the message before transmission and decrypting after reception.

The routine _asgetresp receives either a character array or an error string. On error, it sets errstr and returns –1. If successful, it returns the number of bytes received.

The routine _asgetticket sends a ticket request message and then uses _asgetresp to recieve an answer.

SOURCE
/sys/src/libauthsrv

SEE ALSO
passwd(1), dial(2), cons(3), authsrv(6)

DIAGNOSTICS
These routines set errstr. Integer–valued functions return –1 on error.
Copyright © 2017 Alcatel-Lucent. All rights reserved.