Abstract

The implementation of most network daemons gives little consideration to the implications of worldwide access. In some cases, such access can permit the worldwide distribution of sensitive information, such as encrypted passwords. In other cases, local changes can be effected by processes running anywhere on the network. The shared library mechanism of SunOS can be used to provide a "wrapper" around certain daemons. This wrapper takes the form of an alternate libc shared library. Rather than linking against the standard libc, a daemon is directed to link against this alternate secure library. The secure library has an augmented form of certain network-related system calls which first perform the true system call then check the socket's peer against a configurable list of allowed hosts. If the peer is not found in the list, then the augmented call returns an indication of failure to the caller. 1 The Problem of Network Services Local networking technology has provided a very powerful ...

Citations

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