Re: utilisateur backup
Sam Vilain [EMAIL PROTECTED] writes:
Boris Daix [EMAIL PROTECTED] wrote:
- Can I safely give an SSH key to my backup user without any
passphrase so that it could be automated via cron ?
You can use `ssh-keygen -f single_action_key' to create a key for remote
execution of scripts.
On the remote end, add this key to the `.ssh/authorized_keys' file. You
should add a forced command so that only one command may be executed with
that key.
Good, really interesting !
For rsync(1), you need to capture the exact switches of the rsync server
command.
But I use rsync like a remote copy tool (scp), so do I need this ? If
so, I need tips to better understand what follows... :-)
To do this, you can use this script on the destination server:
#!/usr/bin/perl
open CAPTURE, $ENV{HOME}/capture.log;
print CAPTURE @ARGV\n;
close CAPTURE;
Then add --rsync-path=/path/to/script to your rsync command line. This
will leave something similar to the following in the destination
~/capture.log:
--server -vlgtpr --partial . yourhost
So, you would use an authorized_keys entry like this (all one line):
command=rsync --server -vlogDtpr --partial .
yourhost,no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty,1024
35 23...2334 Server backup key
For more complete security, you could add a `chroot' jail to the above
command.
Are jails useful with rsync used like scp ?
- Is amanda appropriate for this task and would it be more secure
to use it instead ?
- If it is unsecure, how would I do such backups without having to
enter passpgrase/passwd ?
System backups are always an easy entry point, very often they contain
things like secret keys to encryption, etc that will allow a malicious
user to pretend to be the machine that they have access to the backups of.
Protect your backups carefully!
Yes, I've crypted them via gpg :-)
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analysis and nuclear reactor simulation.
many thanks
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Boris Daix
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utilisateur backup
Hi all, I'd like to make backup via cron and I saw there were a user named backup in passwd file. My problem is that the backups should travel via LAN to another machine (running Woody too), so that they backup eachother in fact. I'd like to use rsync to transfer only changes, with SSH to increase security, but my question is : - Can I safely give an SSH key to my backup user without any passphrase so that it could be automated via cron ? - Is amanda appropriate for this task and would it be more secure to use it instead ? - If it is unsecure, how would I do such backups without having to enter passpgrase/passwd ? Thanks a lot -- Boris Daix Feel free to be free, or not to be... -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: utilisateur backup
Mathias Palm [EMAIL PROTECTED] writes: [...] I am using it to backup a bunch of maschines on one tape also using cron. I found it easy to configure and am quite satisfied. You can even configure Amanda in a way that it only transfers changes. On the other hand, Amanda is meant to dump backups on tapes. I cant tell you if there is an easy way to reconfigure it. No tape device here. - If it is unsecure, how would I do such backups without having to enter passpgrase/passwd ? What sort of security do you want? Do you want your backups be encrypted? Amanda can't do that, to my knowledge. I'd like network transfers to be inexploitable by other parts : only admins of both machines should be able to get in backups (that implies file permissions locally, and encrypted communication between stations). Amanda provides some sort of restricted host access. But I cant tell, if it would retain a determined attacker. Otherwise I have not heart of exploits of amanda yet. Lets hope we won't. Thanks a lot Again :-) [...] -- Boris Daix Feel free to be free, or not to be... -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: utilisateur backup
Noah L. Meyerhans [EMAIL PROTECTED] writes:
[...]
So the worst that can happen if the key gets compromised is that the
attacker can trigger a backup of your system. Conceivably this could be
a DoS, at worst. But it's a very common setup. In fact, the standard
method of mirroring Debian involves exactly this type of configuration.
What I wonder is how far the backup user can read (or, worst, even write) to
local fs. If it's just able to look at some /home and /var dirs, and
can write only to /var/backups, it would be enough and I'll be quite
confident. But at this time I don't know how to know this.
- Is amanda appropriate for this task and would it be more secure
to use it instead ?
I am using it to backup a bunch of maschines on one tape also using
cron. I found it easy to configure and am quite satisfied. You can even
configure Amanda in a way that it only transfers changes. On the other
hand, Amanda is meant to dump backups on tapes. I cant tell you if there
is an easy way to reconfigure it.
Amanda has no security. It does not encrypt any of the data going out
over the network. I doesn't support strong host authentication. It
can't be tunnelled over ssh. Tunnelling rdump over ssh is way more
secure than amanda. Running amanda over an IPsec link is a good
approach, and what I use to backup most of my servers.
I don't know IPsec - but I'm too ashame to ask for what it implies
:-)) I'll look for it, but as I won't use amanda ('cause no tape),
backup user may be better if I find what it has access to.
Amanda provides some sort of restricted host access. But I cant tell, if
it would retain a determined attacker.
It supports .amandahosts. It's similar to .rhosts. It can also do
kerberos, but most people don't have a kerberos infrastructure.
noah
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Thanks
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Boris Daix
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