None of the following functions are standard GSS API functions. As such, they are not declared in gss/api.h, but rather in gss/ext.h (which is included from gss.h). See Header.
req_version: version string to compare with, or NULL
Check that the version of the library is at minimum the one given as a string in @req_version.
Return value: The actual version string of the library; NULL if the condition is not met. If NULL is passed to this function no check is done and only the version string is returned.
name: (gss_name_t, read) Name to be compared.
username: Zero terminated string with username.
Compare the username against the output from gss_export_name() invoked on @name, after removing the leading OID. This answers the question whether the particular mechanism would authenticate them as the same principal
Return value: Returns 0 if the names match, non-0 otherwise.