ftpd and shadowing

Hello folks,

has anyone already made expirience with using sshd and password shadowing on uClinux?

I have enabled shadowing within the BusyBox settings. And the i created a new file within /vendors/Altera/common/shadow entering the passwords for every user. Of course i have to modify the Makefile within /vendors/Altera/nios2 so that the shadow file will be copied to the /etc/ directory. Everything seems fine so far and i'am able to loging using telnet. But i can't login using ftp! Does ftpd support shadowing? Or must the passwords stored within /etc/passwd?