authd(8)

NAME
authd - Authentication Server daemon

SYNTAX
authd

DESCRIPTION
authd is a daemon implementing the RFC 931 Authentication Server protocol. It should be invoked by a network server, such as attachport(1) or inetd(8), for connections to TCP port 113 (auth).

The client host gives authd two numbers separated by a comma. authd interprets the numbers as TCP port numbers for the local and remote sides respectively of a TCP connection between this host and the client host. It returns a line of the form
    localport, remoteport: USERID: UNIX: username
where username is the name of the user on this side of the specified connection. If authd does not have an authentication entry for that connection, it returns a line of the form
    localport, remoteport: ERROR: UNKNOWN-ERROR.

DIAGNOSTICS

None.

BUGS
None known.

VERSION
authd version 3.01, February 7, 1991.

AUTHOR
Placed into the public domain by Daniel J. Bernstein. Partially inspired by code written by Vic Abell for ofiles.

REFERENCES
The authentication server is more secure than passwords in some ways, but less secure than passwords in many ways. (It's certainly better than no password at all---e.g., for mail or news.) It is not the final solution. For an excellent discussion of security problems within the TCP/IP protocol suite, see Steve Bellovin's article ``Security Problems in the TCP/IP Protocol Suite.''

SEE ALSO
authtcp(1), attachport(1), authuser(3), tcp(4), inetd(8)