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Name

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

MT-Level

MT-Safe

Description

RPC library routines allow C programs to make procedure calls on other machines across the network.

RPC supports various authentication flavors. Among them are:

AUTH_NONE
(none) no authentication.
AUTH_SYS
Traditional UNIX -style authentication.
AUTH_DES
DES encryption-based authentication.
AUTH_KERB
Kerberos encryption-based authentication.

The authdes_getucred() and authdes_seccreate() routines implement the AUTH_DES authentication flavor. The keyserver daemon keyserv (see keyserv(1M) ) must be running for the AUTH_DES authentication system to work, and keylogin(1) must have been run. Only the AUTH_DES style of authentication is discussed here. For information about the AUTH_NONE and AUTH_SYS styles of authentication, refer to rpc_clnt_auth(3N) . For information about the AUTH_KERB style of authentication, refer to kerberos_rpc(3N) .

The routines documented on this page are MT-Safe. See the pages of the other authentication styles for their MT-level.

Routines

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

#include <rpc/rpc.h>
#include <sys/types.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 user’s group. *gidlist contains the numerical ID s 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).
Warning:
authdes_getucred() will fail if the authdes_cred structure was created with the netname of a host. In such a case, netname2host() should be used on the host netname in the authdes_cred structure to get the host name.


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. If the difference in time between the client’s clock and the server’s clock exceeds window, the server will reject the client’s credentials, and the clock will have to be resynchronized. 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 host on which the server is running.
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.
If
authdes_seccreate() fails, it returns NULL.

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

getnetname()
returns 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. Returns 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. If domain is NULL and host is a NIS name like ‘host1.ssi.sun.com,’ host2netname() uses the domain ‘ssi.sun.com’ rather than the default domain name of the machine.

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. This routine returns 0 if it succeeds, -1 if it fails.

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 calling process. This routine returns 0 if it succeeds, -1 if it fails.

int key_secretkey_is_set(void);

key_secretkey_is_set()
is a keyserver interface routine that may be used to determine whether a key has been set for the effective UID of the calling process. If the keyserver has a key stored for the effective UID of the calling process, this routine returns 1. Otherwise it returns 0.

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[NGRPS ]);

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 user’s group. gidlist contains the numerical ID s 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) , keylogin(1) , keyserv(1M) , newkey(1M) , kerberos_rpc(3N) , rpc(3N) , rpc_clnt_auth(3N)

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