AUTH_SYS

This is the same as the authentication flavor previously known as AUTH_UNIX. The caller of a remote procedure may wish to identify itself using traditional UNIX process permissions authentication. The flavor of the opaque_auth of such an RPC call message is AUTH_SYS. The bytes of the body encode the following structure:

struct auth_sysparms {
  	unsigned int stamp;
  	string machinename<255>;
  	uid_t uid;
  	gid_t gid;
  	gid_t gids<10>;
 };

• stamp is an arbitrary ID that the caller machine may generate.

• machinename is the name of the caller's machine.

• uid is the caller's effective user ID.

• gid is the caller's effective group ID.

• gids is a counted array of groups in which the caller is a member.

The flavor of the verifier accompanying the credentials should be AUTH_NONE.

The AUTH_SHORT Verifier

When using AUTH_SYS authentication, the flavor of the response verifier received in the reply message from the server may be AUTH_NONE or AUTH_SHORT.

If AUTH_SHORT, the bytes of the response verifier's string encode a short_hand_verf structure. This opaque structure may now be passed to the server instead of the original AUTH_SYS credentials.

The server keeps a cache that maps shorthand opaque structures (passed back by way of an AUTH_SHORT style response verifier) to the original credentials of the caller. The caller can save network bandwidth and server cpu cycles by using the new credentials.

The server may flush the shorthand opaque structure at any time. If this happens, the remote procedure call message will be rejected owing to an authentication error. The reason for the failure will be AUTH_REJECTEDCRED. At this point, the caller may wish to try the original AUTH_SYS style of credentials. See Figure B-1.

Figure B-1 Authentication Process Map