but actually for your purpose, I would just buy the cheapest VPS at http://www.buildyourvps.com/

I've got one for about $35 a year. The machine (or probably the network) is heavily oversubscribed, but you get a virtual machine on a dedicated IP address.

---

From: Stanislav Sinyagin ssinyagin@yahoo.com To: "swinog@swinog.ch" swinog@swinog.ch Sent: Friday, June 1, 2012 10:24 AM Subject: Re: [swinog] hosting for 1 powersupply with lan port

Silvan, I would highly recommend pcengines.ch instead. They are quickly available (usually shipped the next day after ordering) from a Swiss store, and so far they are the cheapest linux boxes that I could find. I'm using them exactly for the same purpose - as ssh jumphosts :)

http://linux.voyage.hk/%C2%A0 is a flavor of Debian specifically tailored for these boxes. It mounts the root in read-only mode by default, so your CF storage is written only when needed.

here I put a few related notes in my blog: http://txlab.wordpress.com/tag/voyage-linux/

...

---

From: Silvan M. Gebhardt gebhardt@openfactory.ch To: swinog@swinog.ch Sent: Thursday, May 31, 2012 11:10 PM Subject: [swinog] hosting for 1 powersupply with lan port

Hi Swinogers,

I'm currently thinking about deploying a Sheevaplug or similar with mosh (http://mosh.mit.edu) as a login jumphost since I am several hours in mobile mode every day and I need a space outside of my network to host a *jump host*

please contact me offlist and offer me housing for something like that: http://www.plugcomputer.eu/

All I am taking up is some bandwith (expected bandwith in average probably 1mbit max, half of it for keepalives for outbound vpn tunnels,  Power consumption apparently less than 10watts.

Need v6 and v4 connection, 1 IP each, public, not firewalled, 1 Plug in the power strip

Since this is a rather non-standard thing I'm looking for, but I need it in a datacenter outside my infrastructure, I thought it's best to ask here.

Btw, for anyone experienced already or looking into mosh, looking forward for exchange here

Good Evening!

Silvan

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security by obscurity? you know, with a JTAG adapter and a bit of knowledge, one can read the onboard flash from those plugs too. so, probably a better approach is to have a system which doesn't expose your data when the disk is compromised. The simplest example is SSH with public key authentication and authentication forwarding (-A flag).

---

From: Silvan Gebhardt gebhardt@openfactory.ch To: swinog@lists.swinog.ch Sent: Friday, June 1, 2012 10:28 PM Subject: Re: [swinog] hosting for 1 powersupply with lan port

Hello Stanislav and List

There are two reasons why I want this plug PC:

1. security through obscurity. if someone by whatever means take

this thing apart - an alix is very easy to dump the content off it. a VPS is even worse.

2. such a Plug PC has at least double the ram an alix has, the

moment you want to also run mutt on it it starts to become a bit relevant, with a few dozend openvpn client connections as well.... I do run a lot of Alixes globally already, I do know the whole box quite good.

I'd love to keep this box in switzerland as well ;)

Thanks for the input, mosh will be a topic I will update the ML if

the interest is there - I'm looking forward to see how it behaves on sat connections etc.

Silvan

Am 01.06.2012 10:36, schrieb Stanislav Sinyagin:

...

but actually for your purpose, I would just buy the cheapest VPS at http://www.buildyourvps.com/

I've got one for about $35 a year. The machine (or probably the network) is heavily oversubscribed, but you get a virtual machine on a dedicated IP address.

...

---

From: Stanislav Sinyagin ssinyagin@yahoo.com To: "swinog@swinog.ch" swinog@swinog.ch Sent: Friday, June 1, 2012 10:24 AM Subject: Re: [swinog] hosting for 1 powersupply with lan port

Silvan, I would highly recommend pcengines.ch instead. They are quickly available (usually shipped the next day after ordering) from a Swiss store, and so far they are the cheapest linux boxes that I could find. I'm using them exactly for the same purpose - as ssh jumphosts :)

http://linux.voyage.hk/%C2%A0 is a flavor of Debian specifically tailored for these boxes. It mounts the root in read-only mode by default, so your CF storage is written only when needed.

here I put a few related notes in my blog: http://txlab.wordpress.com/tag/voyage-linux/

...

---

From: Silvan M. Gebhardt gebhardt@openfactory.ch To: swinog@swinog.ch Sent: Thursday, May 31, 2012 11:10 PM Subject: [swinog] hosting for 1 powersupply with lan port

Hi Swinogers,

I'm currently thinking about deploying a Sheevaplug or similar with mosh (http://mosh.mit.edu) as a login jumphost since I am several hours in mobile mode every day and I need a space outside of my network to host a *jump host*

please contact me offlist and offer me housing for something like that: http://www.plugcomputer.eu/

All I am taking up is some bandwith (expected bandwith in average probably 1mbit max, half of it for keepalives for outbound vpn tunnels,  Power consumption apparently less than 10watts.

Need v6 and v4 connection, 1 IP each, public, not firewalled, 1 Plug in the power strip

Since this is a rather

non-standard thing I'm looking for, but I need it in a datacenter outside my infrastructure, I thought it's best to ask here.

...

...

...

Btw, for anyone experienced already or looking into mosh, looking forward for exchange here

Good Evening!

Silvan

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Good Morning!

The cloud is completely anonymous, that makes the feeling to do something (as a provider) much lower in my opinion. Knowing someone, even the face, is much better. Since I know this point I did not call it "physical security" but "security through obscurity" on purpose. Since such a plug PC makes extraction of data a bit more complex - possible always - I gain time. Time when the box is offline to revoke my keys ;)

I do have to trust the people I will be hosting it with, there is a reason I do it in switzerland. (Yes, I belive after beeing the nation of money we will be the *data bankers* soon)

@Stanislav: Interesting flag with SSH -A - I will have to read there futher, is this something like PFS with IPSEC? never heard about that flag.

I think we are creating a topic for next swinog here. "Networking for Mobile workers (Mosh) with paranoia"

Am 02.06.2012 08:57, schrieb Viktor Steinmann:

Interesting topic, especially looking at the current cloud trends. We've been discussing this internally and came to the conclusion, that as long as someone has physical access to a server, he will always be capable of reading the data on that server with more or less effort.

Even using a high level of physical security to ensure, nobody has physical access to the box can be broken with enough time and effort, especially from the people housing the box.

In the end, all you need is trust. If you trust the people housing your box and if you trust their ability to keep the bad guys physically away, everything is fine. If you can't trust them you are lost in any case.

Kind regards, Viktor

Am 02.06.2012 01:05, schrieb Stanislav Sinyagin:

...

security by obscurity? you know, with a JTAG adapter and a bit of knowledge, one can read the onboard flash from those plugs too. so, probably a better approach is to have a system which doesn't expose your data when the disk is compromised. The simplest example is SSH with public key authentication and authentication forwarding (-A flag).

---

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ok, more to the details.

I. SSH auth. forwarding =================

on my PC, I have my private SSH key, encrypted with a good password. As I control this environment, I make sure this is the only copy of my private key, and all backup copies are encrypted with other passwords.

On my VPS that I use as a jumphost, I have my public key in .ssh/authorized_keys. So my login does not even have a password on that server.

When I'm logged in to the VPS, I can do

ssh -A ssinyagin@1.2.3.4 with this command, the server 1.2.3.4 authenticates me through my public key, and the VPS acts as the SSH agent proxy. So, if that server has my public key in .ssh/authorized_keys, I'm easily in, and no security breach on the VPS would affect my security.

II. Secure data on a foreign machine ==========================

so, your VPS is in an untrusted environment, and you need to store sensitive data on it (e.g. VPN configuration and keys).

You create a cryptfs folder, mount it with a manually entered password, and store your sensitive data on it. As long as the server is running, your processes can access the data. If the server reboots, it needs to notify the operator via email or SMS, and the operator logs in and mounts the cryptfs again.

Of course depending on the virtualization technology, your provider may log in from the VM console and see your data. So, you either trust your provider, or use a physical machine like pcengines. On the latest DENOG meeting, there was an interesting report that offline RAM chips still hold traces of your data for few hours, so be careful with that too :)

As an alternative to cryptfs, you can mount a RAM disk and initialize its content from your home location via an SSH tunnel. If you use Git, you can also do incremental updates to the running system.

III. Off-site backups ==============

what I do is let my home NAS pack the data directory, encrypt it with AES256, and push towards the VPS server. So, nightly I transfer a few hundred megabytes. It works fine as long as I keep the footprint within reasonable limits.

As an alternative, there was somewhere a project that modifies rsync in a way that it can work with encrypted data on the remote site.

did I miss something?

---

From: Silvan Gebhardt gebhardt@openfactory.ch To: swinog@lists.swinog.ch Sent: Saturday, June 2, 2012 11:50 AM Subject: Re: [swinog] hosting for 1 powersupply with lan port

Good Morning!

The cloud is completely anonymous, that makes the feeling to do

something (as a provider) much lower in my opinion. Knowing someone, even the face, is much better. Since I know this point I did not call it "physical security" but "security through obscurity" on purpose. Since such a plug PC makes extraction of data a bit more complex - possible always  - I gain time. Time when the box is offline to revoke my keys ;)

I do have to trust the people I will be hosting it with, there is a

reason I do it in switzerland. (Yes, I belive after beeing the nation of money we will be the *data bankers* soon)

@Stanislav: Interesting flag with SSH -A - I will have to read there

futher, is this something like PFS with IPSEC? never heard about that flag.

I think we are creating a topic for next swinog here. "Networking

for Mobile workers (Mosh) with paranoia"

Am 02.06.2012 08:57, schrieb Viktor Steinmann: Interesting topic, especially looking at the current cloud trends. We've been discussing this internally and came to the conclusion, that as long as someone has physical access to a server, he will always be capable of reading the data on that server with more or less effort.

...

Even using a high level of physical security to ensure, nobody has

physical access to the box can be broken with enough time and effort, especially from the people housing the box.

...

In the end, all you need is trust. If you trust the people housing

your box and if you trust their ability to keep the bad guys physically away, everything is fine. If you can't trust them you are lost in any case.

...

Kind regards, Viktor

Am 02.06.2012 01:05, schrieb Stanislav Sinyagin: security by obscurity?

...

you know, with a JTAG adapter and a bit of knowledge, one can read the onboard flash from those plugs too. so, probably a better approach is to have a system which doesn't expose your data when the disk is compromised. The simplest example is SSH with public key authentication and authentication forwarding (-A flag).

---

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From: Jeroen Massar jeroen@unfix.org To: Stanislav Sinyagin ssinyagin@yahoo.com Cc: Silvan Gebhardt gebhardt@openfactory.ch; "swinog@lists.swinog.ch" swinog@lists.swinog.ch Sent: Saturday, June 2, 2012 4:05 PM Subject: Re: [swinog] hosting for 1 powersupply with lan port

On 2 Jun 2012, at 05:49, Stanislav Sinyagin ssinyagin@yahoo.com wrote:

When I'm logged in to the VPS, I can do

...

ssh -A ssinyagin@1.2.3.4 with this command, the server 1.2.3.4 authenticates me through my public key, and the VPS acts as the SSH agent proxy. So, if that server has my public key in .ssh/authorized_keys, I'm easily in, and no security breach on the VPS would affect my security.

Unless the attacker is on the jumpbox as root as then they can also forward in the same way, but this should not happen ofcourse ;)

yes

another way to avoid the ssh agent intrusion is to use TCP tunneling through SSH. Then the intermediate host is only used for TCP connection bridging, but all the authentication is happening outside of your jumphost.

----- Original Message -----

From: Stanislav Sinyagin ssinyagin@yahoo.com

...

---

From: Jeroen Massar jeroen@unfix.org

On 2 Jun 2012, at 05:49, Stanislav Sinyagin ssinyagin@yahoo.com

wrote:

...

When I'm logged in to the VPS, I can do

...

ssh -A ssinyagin@1.2.3.4 with this command, the server 1.2.3.4 authenticates me through my public

key, and the VPS acts as the SSH agent proxy. So, if that server has my public key in .ssh/authorized_keys, I'm easily in, and no security breach on the VPS would affect my security.

...

Unless the attacker is on the jumpbox as root as then they can also forward

in the same way, but this should not happen ofcourse ;)

yes, in theory if the attacker is logged in as root, then during my SSH session they may make an SSH connection using my credentials. But it would be difficult to stay unnoticed, and it's only possible while I'm logged in.

Here you have: http://www.remlab.net/ndisc6/

Roque

On Mon, Jun 4, 2012 at 9:59 PM, Tobias Brunner tobias.brunner@nine.chwrote:

Hi,

Does someone know if there is a tool for linux which can send a neighbor advertisement for a fast update of the neighbor table of a router? Like to good old "arping -U" for ipv4 which sends gratuitous/unsolicited arp messages...

Have a nice evening!

Cheers, Tobias

-- Nine Internet Solutions AG, Albisriederstr. 243a, CH-8047 Zuerich Support +41 44 637 40 40 | Tel +41 44 637 40 00 | Direct +41 44 637 40 13 Skype nine.ch_support

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On Mon, 4 Jun 2012, Tobias Brunner wrote:

Hi,

Does someone know if there is a tool for linux which can send a neighbor advertisement for a fast update of the neighbor table of a router? Like to good old "arping -U" for ipv4 which sends gratuitous/unsolicited arp messages...

ndp(1) auf FreeBSD, "ip neighbour" kann so was bei Linux.

//Saper

On 2012-06-04 13:43, Tobias Brunner wrote:

Hi all,

Danke für die Antworten!!

• ndisc6 macht irgendwie nicht das, was ich erwarte

ndisc6 <adresse> eth0 Soliciting <adresse> (<adresse>) on eth0... Timed out. Timed out. Timed out. No response.

$ ndisc6 2001:4f8:3:2e::1 eth0 Soliciting 2001:4f8:3:2e::1 (2001:4f8:3:2e::1) on eth0... Target link-layer address: 00:11:BC:A5:48:00 from 2001:4f8:3:2e::1

Do note that if the address does not exist you get what you showed:

$ ndisc6 2001:4f8:3:2e::2 eth0 Soliciting 2001:4f8:3:2e::2 (2001:4f8:3:2e::2) on eth0... Timed out. Timed out. Timed out. No response.

• ndping lässt sich nicht kompilieren (siehe unten)
• ip neighbor werde ich morgen testen, das klingt vielversprechend!

'ip nei' can be used to look at the current entries, it does not allow for sending a ND solication, but effectively one can also do:

in one shell: tcpdump -i eth0 icmp6 in another: ping6 -i eth0 <address>

should give you the packets too unless it is cached, but then you can remove it with 'ip nei flush ...' to force it to be cached again.

Note that 'ip -4 nei' is effectively showing the ARP tables, while 'ip -6 nei' is for the ND based information.

PS: Sorry für das Durcheinander mit den Threads in der Mailinglist =)

Or the mixing of English and German ;)

gcc -o ndping ndping.c -Wall -lnet -lpcap ndping.c: In function ‘callback’: ndping.c:65: error: ‘LIBNET_ICMPV6_NS_H’ undeclared (first use in this function)

You need to install the libnet headers for that to work.

Greets, Jeroen

On Sat, 02 Jun 2012 11:50:59 +0200 Silvan Gebhardt gebhardt@openfactory.ch wrote:

The cloud is completely anonymous, that makes the feeling to do something (as a provider) much lower in my opinion. Knowing someone, even the face, is much better. Since I know this point I did not call it "physical security" but "security through obscurity" on purpose. Since such a plug PC makes extraction of data a bit more complex - possible always - I gain time. Time when the box is offline to revoke my keys ;)

Fill the box with thermally conductive epoxy. No way to get at the data anymore unless you take a lot of time to drill a few holes ... but not too deep! ;-)

If you need more security, then there are a few techniques that are able to erase memory as soon as the case is opened or broken. But those require custom devices and are thus a bit more expensive.

Attila Kinali