sshd: Authentication refused: bad ownership or modes for directory /data
I’m trying ssh-ing into a rooted Android phone, but it gives me an error Permission denied (publickey).
, and the log says Authentication refused: bad ownership or modes for directory
, despite of the fact I have configured the permissions and ownerships carefully and correctly as shown below.
Here is the content of the file sshd_config
.
- /data/ssh/sshd_config
AuthorizedKeysFile /data/.ssh/authorized_keys
ChallengeResponseAuthentication no
PasswordAuthentication no
PubkeyAuthentication yes
PermitRootLogin yes
Subsystem sftp internal-sftp
pidfile /data/ssh/sshd.pid
Here is the content of the file 99sshd
.
- /data/local/userinit.d/99sshd
#!/system/bin/sh
umask 077
# DEBUG=1
DSA_KEY=/data/ssh/ssh_host_dsa_key
DSA_PUB_KEY=/data/ssh/ssh_host_dsa_key.pub
RSA_KEY=/data/ssh/ssh_host_rsa_key
RSA_PUB_KEY=/data/ssh/ssh_host_rsa_key.pub
AUTHORIZED_KEYS=/data/.ssh/authorized_keys
DEFAULT_AUTHORIZED_KEYS=/data/.ssh/authorized_keys
if [ ! -f $DSA_KEY ]; then
/system/bin/ssh-keygen -t dsa -f $DSA_KEY -N ""
chmod 600 /$DSA_KEY
chmod 644 $DSA_PUB_KEY
fi
if [ ! -f $RSA_KEY ]; then
/system/bin/ssh-keygen -t rsa -f $RSA_KEY -N ""
chmod 600 /$RSA_KEY
chmod 644 $RSA_PUB_KEY
fi
if [[ ! -f $AUTHORIZED_KEYS && -f $DEFAULT_AUTHORIZED_KEYS ]]; then
cat $DEFAULT_AUTHORIZED_KEYS > $AUTHORIZED_KEYS
fi
if [ "1" == "$DEBUG" ] ; then
# run sshd in debug mode and capture output to logcat
/system/bin/logwrapper /system/bin/sshd -f /data/ssh/sshd_config -D -d
else
# don't daemonize - otherwise we can't stop the sshd service
/system/bin/sshd -f /data/ssh/sshd_config -D
fi
Also I’m making sure the client pubkey is in /data/.ssh/authorized_keys
.
Now, here are the permissions and ownerships of the related files and directories.
# ls -alt /data/ssh
total 56
-rw-r--r-- 1 root root 6 2023-11-16 11:56 sshd.pid
-rw-rw---- 1 root root 269 2023-11-16 10:53 sshd_config
drwxrwx--x 54 system system 4096 2023-11-16 10:47 ..
drwxr-x--- 3 root shell 4096 2023-11-16 10:13 .
-rw------- 1 root root 505 2023-11-16 10:11 ssh_host_ecdsa_key
-rw-r--r-- 1 root root 176 2023-11-16 10:11 ssh_host_ecdsa_key.pub
-rw------- 1 root root 411 2023-11-16 10:11 ssh_host_ed25519_key
-rw-r--r-- 1 root root 96 2023-11-16 10:11 ssh_host_ed25519_key.pub
-rw-r--r-- 1 root root 604 2023-11-16 10:11 ssh_host_dsa_key.pub
-rw------- 1 root root 1381 2023-11-16 10:11 ssh_host_dsa_key
-rw-r--r-- 1 root root 568 2023-11-16 10:11 ssh_host_rsa_key.pub
-rw------- 1 root root 2602 2023-11-16 10:11 ssh_host_rsa_key
drw------- 2 root shell 4096 1974-02-26 03:43 empty
# ls -alt /data/.ssh
total 16
drwxrwx--x 54 system system 4096 2023-11-16 10:47 ..
-rw------- 1 root root 1144 2023-11-16 10:17 authorized_keys
drwx------ 2 root root 4096 2023-11-16 10:00 .
# ls -alt /data/local/userinit.d/99sshd
-rwxr-xr-x 1 root root 969 2023-11-16 10:54 /data/local/userinit.d/99sshd
Now run the sshd server.
# /data/local/userinit.d/99sshd
On a client machine, I try to connect to the phone like usual.
PS C:Usersuser> ssh root@192.168.4.159
root@192.168.4.159: Permission denied (publickey).
And fails as the error as shown above.
So I checked the log on the phone, the log says like this below.
# logcat | grep -i ssh
11-16 11:56:28.394 10599 10599 I /system/bin/sshd: Authentication refused: bad ownership or modes for directory /data
But I can’t see any permissions or ownerships problem forthe related files, as I’ve shown above.
For a Note, I referenced:
The phone is:
- ASUS ZenFone3 Android 10
Thanks for your help.
You should set /data and its subdirectories to be owned by root with permissions 0755 (rwxr-xr-x). Alternately, you can disable this permissions check by setting StrictModes to "no" in the sshd_config file on the phone.
The error message is specifically about the /data directory. According to the source code, for the authorized_keys file, sshd
checks that all directories in the absolute path to the file are owned by either the user or root, and that no directory is group- or world-writable. In your case, this is the /data directory:
drwxrwx--x 54 system system 4096 2023-11-16 10:47 ..
In other words, group write access is enabled, and (until you changed it in the comments), the owner and group is "system". Both of these are unacceptable for a login attempt as "root".