pam_chauthtok functions returns PAM_SUCCESS instead of error in RHEL5

Issue

When calling pam_chauthtok, from C++ code, in situations where a "BAD PASSWORD" error would be expected, "PAM_SUCCESS" is returned instead. Testing from the command line returns expected results.

The /etc/pam.d/check_password used is shown below:

auth        required      pam_unix.so nullok try_first_pass

password    required      pam_passwdqc.so min=8,8,8,8,8 max=10 passphrase=0 match=0 similar=deny random=0 enforce=users retry=3
password    sufficient    pam_unix.so nullok use_authtok md5 shadow remember=5