NAME

       remctl_set_ccache - Set credential cache for remctl client connections

SYNOPSIS

       #include <remctl.h>

       int remctl_set_ccache(struct remctl *r, const char *ccache);

DESCRIPTION

       remctl_set_ccache() tells the the remctl client library to use ccache as the credential
       cache for authentication to a remctl server.  It will affect any subsequent remctl_open()
       calls on the same struct remctl object (and may have broader effects; see WARNINGS below).
       ccache is normally a path to a file in the file system that holds Kerberos credentials,
       but may take other values depending on the underlying Kerberos implementation used by GSS-
       API.

       Calling this function will normally override any KRB5CCNAME environment setting.  If the
       caller wishes to honor that setting, it should either not call this function or check
       whether that environment variable is set first.

RETURN VALUE

       remctl_set_ccache() returns true on success and false on failure.  On failure, the caller
       should call remctl_error() to retrieve the error message.

       This function will always return failure if the underlying GSS-API implementation against
       which the remctl client library was compiled does not support setting the Kerberos
       credential cache.  The caller should be prepared for that.  Falling back on setting the
       KRB5CCNAME environment variable is often a reasonable choice.

EXAMPLES

       Here's an example of attempting to use this function to set a ticket cache location and
       falling back on setting KRB5CCNAME in the environment if this function is not supported.

           struct remctl r;

           r = remctl_new();
           if (r != NULL)
               if (!remctl_set_ccache(r, "/tmp/krb5cc_example"))
                   putenv("KRB5CCNAME=/tmp/krb5cc_example");

       This assumes that any failure is due to lack of support from the underlying library rather
       than some other cause.

COMPATIBILITY

       This interface was added in version 3.0, but that version would always change the ticket
       cache used by all GSS-API calls in the same process.  Support for the
       gss_krb5_import_cred() method of isolating the changed ticket cache to only this remctl
       client object was added in version 3.5.

WARNINGS

       The effect of this function is only localized to this specific remctl client context if
       the remctl client library was built against a Kerberos as well as GSS-API library and the
       GSS-API library supported gss_krb5_import_cred().  Otherwise, it falls back to calling
       gss_krb5_ccache_name(), which sets the credential cache used by the underlying GSS-API
       library for every GSS-API operation in the current execution context (process or thread),
       not just for this remctl object or even just for remctl operations.  This function may
       therefore change global execution state and may affect other GSS-API operations done
       elsewhere in the same process.

AUTHOR

       Russ Allbery <eagle@eyrie.org>

COPYRIGHT AND LICENSE

       Copyright 2011, 2013, 2014 The Board of Trustees of the Leland Stanford Junior University

       Copying and distribution of this file, with or without modification, are permitted in any
       medium without royalty provided the copyright notice and this notice are preserved.  This
       file is offered as-is, without any warranty.

SEE ALSO

       remctl_new(3), remctl_open(3), remctl_error(3)

       The current version of the remctl library and complete details of the remctl protocol are
       available from its web page at <http://www.eyrie.org/~eagle/software/remctl/>.