It's my first time of using sshd, but failed. Here are my steps to config sshd on QNX6.4.1.

1. edit the /etc/ssh/sshd_config 
 Port 22
 Protocol 2
 AddressFamily any
 ListenAddress 192.168.32.129
 HostKey /etc/ssh/ssh_host_rsa_key
 #HostKey /etc/ssh/ssh_host_dsa_key
 ServerKeyBits 2048
 LoginGraceTime 600
 KeyRegenerationInterval 3600
 PermitRootLogin yes
 IgnoreRhosts yes
 IgnoreUserKnownHosts yes
 StrictModes yes
 X11Forwarding no
 PrintMotd yes
 SyslogFacility AUTH
 LogLevel INFO
 RhostsRSAAuthentication yes
 RSAAuthentication yes
 PasswordAuthentication yes
 PermitEmptyPasswords no
 AllowUsers root
 Subsystem	sftp	/usr/libexec/sftp-server
 

2. using ssh-keygen to produce private key and public key:
ssh-keygen -b2048 -trsa -f/etc/ssh/ssh_host_rsa_key -N"12345678" -C"shenxifeng"

and get the result :
Your identification has been saved in /etc/ssh/ssh_host_rsa_key.
Your public key has been saved in /etc/ssh/ssh_host_rsa_key.pub.
The key fingerprint is:
93:94:f0:d7:4e:d4:55:23:d8:47:b3:b5:dd:16:39:2c shenxifeng

3.start sshd:
/usr/sbin/sshd -ddd

output:

debug1: HPN Buffer Size: 32768
debug1: sshd version OpenSSH_5.0 QNX_Secure_Shell-20081228
debug3: Not a RSA1 key file /etc/ssh/ssh_host_rsa_key.
debug1: PEM_read_PrivateKey failed
debug1: read PEM private key done: type <unknown>
Could not load host key: /etc/ssh/ssh_host_rsa_key
Disabling protocol version 2. Could not load host key
sshd: no hostkeys available -- exiting.


Please Help, Thanks in advance.