NAME

secure_rpc: authdes_seccreate, authdes_getucred, getnetname, host2netname, key_decryptsession, key_encryptsession, key_gendes, key_setsecret, netname2host, netname2user, user2netname - library routines for secure remote procedure calls

DESCRIPTION

RPC library routines allow C programs to make procedure calls on other machines across the network. First, the client calls a procedure to send a data packet to the server. Upon receipt of the packet, the server calls a dispatch routine to perform the requested service, and then sends back a reply. RPC supports various authentication flavors. Among them are:

     AUTH_NONE      (none)  no authentication.
     AUTH_SYS       Traditional UNIXr-style authentication.
     AUTH_DES       DES encryption-based authentication.
The authdes_getucred and authdes_seccreate  routines  imple-
ment the AUTH_DES authentication flavor.  The keyserver dae-
mon keyserv  [see  keyserv(1M)]  must  be  running  for  the
AUTH_DES authentication system to work.

Routines

See rpc(3N) for the definition of the AUTH data structure.

#include <rpc/rpc.h>
int
authdes_getucred(const struct authdes_cred *adc, uid_t *uidp,
     gid_t *gidp, short *gidlenp, gid_t *gidlist);

authdes_getucred is the first of the two routines which interface to the RPC secure authentication system known as AUTH_DES. The second is authdes_seccreate, below. authdes_getucred is used on the server side for converting an AUTH_DES credential, which is operating system independent, into an AUTH_SYS credential. This routine returns 1 if it succeeds, 0 if it fails.

*uidp is set to the user's numerical ID associated with adc. *gidp is set to the numerical ID of the group to which the user belongs. *gidlist contains the numerical IDs of the other groups to which the user belongs. *gidlenp is set to the number of valid group ID entries in *gidlist [see netname2user, below].

AUTH *
authdes_seccreate(const char *name, const unsigned int window,
     const char *timehost, const des_block *ckey);

authdes_seccreate, the second of two AUTH_DES authentication routines, is used on the client side to return an authentication handle that will enable the use of the secure authentication system. The first parameter name is the network name, or netname, of the owner of the server process. This field usually represents a hostname derived from the utility routine host2netname, but could also represent a user name using user2netname, described below. The second field is window on the validity of the client credential, given in seconds. A small window is more secure than a large one, but choosing too small of a window will increase the frequency of resynchronizations because of clock drift. The third parameter, timehost, the host's name, is optional. If it is NULL, then the authentication system will assume that the local clock is always in sync with the timehost clock, and will not attempt resynchronizations. If a timehost is supplied, however, then the system will consult with the remote time service whenever resynchronization is required. This parameter is usually the name of the RPC server itself. The final parameter ckey is also optional. If it is NULL, then the authentication system will generate a random DES key to be used for the encryption of credentials. If ckey is supplied, then it will be used instead.

int
getnetname(char name[MAXNETNAMELEN+1]);

getnetname  installs   the   unique,   operating-system
independent  netname  of the caller in the fixed-length
array name.  Returns 1 if it  succeeds,  and  0  if  it
fails.
int
host2netname(char name[MAXNETNAMELEN+1], const char *host,
     const char *domain);

Convert from a domain-specific hostname host to an operating-system independent netname. Return 1 if it succeeds, and 0 if it fails. Inverse of netname2host. If domain is NULL, host2netname uses the default domain name of the machine. If host is NULL, it defaults to that machine itself.

int
key_decryptsession(const char *remotename, des_block *deskey);

key_decryptsession is an interface to the keyserver daemon, which is associated with RPC's secure authentication system (AUTH_DES authentication). User programs rarely need to call it, or its associated routines key_encryptsession, key_gendes and key_setsecret.

key_decryptsession takes a server netname remotename and a DES key deskey, and decrypts the key by using the the public key of the the server and the secret key associated with the effective UID of the calling process. It is the inverse of key_encryptsession.

int
key_encryptsession(const char *remotename, des_block *deskey);

key_encryptsession is a keyserver interface routine. It
takes a server netname remotename and a DES key deskey,
and encrypts it using the public key of the the  server
and the secret key associated with the effective UID of
the   calling   process.   It   is   the   inverse   of
key_decryptsession.   This  routine  returns  0  if  it
succeeds, -1 if it fails.
int
key_gendes(des_block *deskey);

key_gendes is a keyserver interface routine. It is used
to  ask  the  keyserver  for a secure conversation key.
Choosing one at random  is  usually  not  good  enough,
because  the  common  ways  of choosing random numbers,
such as using the current time, are very easy to guess.
int
key_setsecret(const char *key);

key_setsecret is a keyserver interface routine.  It  is
used  to  set the key for the effective UID of the cal-
ling process.  this routine returns 0 if  it  succeeds,
-1 if it fails.
int
netname2host(const char *name, char *host, const int hostlen);

Convert from an operating-system independent netname name to a domain-specific hostname host. hostlen is the maximum size of host. Returns 1 if it succeeds, and 0 if it fails. Inverse of host2netname.

int
netname2user(const char *name, uid_t *uidp, gid_t *gidp,
     int *gidlenp, gid_t gidlist[NGROUPS]);

Convert from an operating-system independent netname to a domain-specific user ID. Returns 1 if it succeeds, and 0 if it fails. Inverse of user2netname.

*uidp is set to the user's numerical ID associated with name. *gidp is set to the numerical ID of the group to which the user belongs. gidlist contains the numerical IDs of the other groups to which the user belongs. *gidlenp is set to the number of valid group ID entries in gidlist.

int
user2netname(char name[MAXNETNAMELEN+1], const uid_t uid,
     const char *domain);

Convert  from  a   domain-specific   username   to   an
operating-system  independent netname.  Returns 1 if it
succeeds, and 0 if it fails.  Inverse of netname2user.

SEE ALSO

chkey(1), keyserv(1M), newkey(1M), rpc(3N),
rpc_clnt_auth(3N).