umask for internal-sftp users ?

[Vilius Mockūnas]

Hello,

Running Debian 5.
SSH version 5.1p1-5.

How do I set umask for sftp only users ?

Users are jailed - that means they use internal-sftp:
   # cat /etc/ssh/sshd_config
   ..........
  Match group group1
        ChrootDirectory /home/%u
        X11Forwarding no
        AllowTcpForwarding no
        ForceCommand internal-sftp
   ..........


thanks
Vilius