In SSSD, we use dlopen() and dlsym() in two files
src/providers/data_provider_be.c and src/providers/proxy/proxy_init.c.
Hence we should explicitly link with -ldl also in simple_access-tests.

SSSD can be compiled with two crypto libraries nss or libcrypto. NSS has
dependency nspr which depends on "libdl and libpthread" This is a reason why
compilation of test did not fail even if -ldl was not explicitly added to
simple_access_tests_LDADD. But libcrypto doesn't depend on libdl, so in
this case compilation of tests will not be successful.

Upstream nspr 4.9 has two ways have to obtain metainformation about
libraries
pkg-config and own script nspr-config. First one doesn't list "-ldl"
"-lpthread" but second one lists both "-ldl" "-lpthread"

That's also why the Ubuntu maintainer found this bug -- Fedora has got
patched version of nspr, but Debian (Ubuntu) doesn't

Enterprise principals are currently most useful for the AD provider and
hence enabled here by default while for the other Kerberos based
authentication providers they are disabled by default.

If additional UPN suffixes are configured for the AD domain the user
principal stored in the AD LDAP server might not contain the real
Kerberos realm of the AD domain but one of the additional suffixes which
might be completely randomly chooses, e.g. are not related to any
existing DNS domain. This make it hard for a client to figure out the
right KDC to send requests to.

To get around this enterprise principals (see
http://tools.ietf.org/html/rfc6806 for details) were introduced.
Basically a default realm is added to the principal so that the Kerberos
client libraries at least know where to send the request to. It is not
in the responsibility of the KDC to either handle the request itself,
return a client referral if he thinks a different KDC can handle the
request or return and error. This feature is also use to allow
authentication in AD environments with cross forest trusts.

Fixes https://fedorahosted.org/sssd/ticket/1842

Different user and group lookup requests used nearly identical code,
this patch unifies some of the related code paths.

The task of get_my_domain_data() is to read some information about the
configured domain from the cache. While the sysdb interface was
redesigned some changes changed the behaviour so that the data of the
domain of the current request was read. If this domain is a sub-domain
the wrong data was read. As a result group-memberships of the configured
domain were not taken into account.

The original code didn't made it easy to see that always the parent
domain should be used here, because there was no comment indication this
and the function name get_my_domain_data() didn't made it clear either.
Additionally to fixing the issue this patch also adds a comment and
rename the function to get_parent_domain_data().

Fixes https://fedorahosted.org/sssd/ticket/1888

https://fedorahosted.org/sssd/ticket/453

It makes sense to keep using the boolean for access granted/denied, but
when the user/group is not found, the request would now return
ERR_ACCOUNT_UNKNOWN

https://fedorahosted.org/sssd/ticket/1799

One peculiarity of the sysdb_attrs_get_el interface is that if the
attribute does not exist, then the attrs array is reallocated and the
element is created. But in case other pointers are already pointing
into the array, the realloc might invalidate them.

Such case was in the sdap_process_ghost_members function where if
the group had no members, the "gh" pointer requested earlier might have
been invalidated by the realloc in order to create the member element.

* Remove check-specific failure reporting from common_check.c
* Check-specific abstraction over memleak checks
* Rename common_check.c to leak_check.c