FS#30278 - [procps-ng] /etc/sysctl.conf - add and enable IPv6 privacy extensions
Attached to Project:
Arch Linux
Opened by Sir Pogsalot (Pogs) - Wednesday, 13 June 2012, 09:24 GMT
Last edited by Gaetan Bisson (vesath) - Monday, 17 September 2012, 08:13 GMT
Opened by Sir Pogsalot (Pogs) - Wednesday, 13 June 2012, 09:24 GMT
Last edited by Gaetan Bisson (vesath) - Monday, 17 September 2012, 08:13 GMT
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Details
Description:
It is my opinion that IPv6 and its "stateless address autoconfiguration" is a privacy concern to those few of us who are lucky enough to have a global IPv6 address. The problem is that IPv6 in that schenario will form your global address by using a portion of your network interface's MAC when auto-assigning what address the interface will take on. [1] This in turn will make it easier for certain companies interested in tracking your behavior on the web to collect information about you. While the prefix of the address from the ISP may change, the MAC address portion will make it much easier for sites like Facebook to collect behavioral analysis data (if they do already or choose to in the future). I don't want to get into a discussion about paranoia and anonymity, and I'm sorry I alluded to what (might) already be a practice among companies that do data mining, but I thought it would be important to at least explain why I want this. TL;DR: I would like to suggest that the maintainer/owner of procps-ng please add the following options (enabled) to /etc/sysctl.conf: # Enable IPv6 Privacy Extensions net.ipv6.conf.default.use_tempaddr = 2 net.ipv6.conf.all.use_tempaddr = 2 #net.ipv6.conf.<nic0>.use_tempaddr = 2 #net.ipv6.conf.<nicN>.use_tempaddr = 2 As I understand it, this will make the global address it forms for the interface be generated randomly, for all interfaces (this was copied from Arch's Wiki). It is my opinion that the average user will not take time to look at or configure anything in /etc/sysctl.conf so it is important that we encourage use of the IPv6 privacy extensions by it being enabled from a stock Arch installation. With Wikipedia saying that Windows and Mac OS X both have IPv6 privacy extensions enabled by default, I was hoping it would be an easy "feature" to add with the consensus of those who will handle this report. In terms of what is gained and lost: Privacy is gained, nothing is lost, as autogenerated global IPv6 addresses are also handled for collisions (in the incredible chance that ever happens. This is about keeping LAN information on the LAN, and not advertising your MAC address to the rest of the internet. :> Sources: 1) http://en.wikipedia.org/wiki/IPv6_stateless_address_autoconfiguration#Privacy 2) http://en.wikipedia.org/wiki/IPv6#Privacy 3) https://wiki.archlinux.org/index.php/IPv6 Additional info: * I am using procps-ng 3.3.3-1 * IPv6 privacy extensions are not enabled or mentioned in the stock /etc/sysctl.conf Closing: I hope that I am correct in everything I have discussed/suggested here, I have witnessed this "breach of privacy" after having been moved to AT&T's Uverse fiber network earlier today. Please enable these privacy extensions so that others may not be caught unawares. |
This task depends upon
Closed by Gaetan Bisson (vesath)
Monday, 17 September 2012, 08:13 GMT
Reason for closing: Won't implement
Additional comments about closing: Enabling IPv6 privacy extensions by default goes against both the RFC and the default configuration of its Linux implementation.
Monday, 17 September 2012, 08:13 GMT
Reason for closing: Won't implement
Additional comments about closing: Enabling IPv6 privacy extensions by default goes against both the RFC and the default configuration of its Linux implementation.
I am not _against_ companies collecting information on you, it does have its benefits -- from targetted advertising to how Facebook can magically connect you to people and organizations with similar interests. BUT: I do not believe this is a way to collect information they should have access to as it requires you to know about its existence to opt out of.
I'm someone in favor of giving people "implicit" privacy, and letting them relinquish it themselves.
I hope this helps balance out my argument.
^ This should actually be there on top of having net.ipv6.conf.all.use_tempaddr = 2
It turns out *.all.use_tempaddr affects only the addresses generated on interfaces brought up later, not those at boot. Since eth0 is referenced in the stock rc.conf (iirc) it seems okay that specifically defining IPv6 privacy extensions on eth0 (assuming it exists) is the "right thing". I wish *.all.use_tempaddr worked as I expected...
Corrected addition to /etc/sysctl.conf:
# Enable IPv6 Privacy Extensions
net.ipv6.conf.default.use_tempaddr = 2
net.ipv6.conf.all.use_tempaddr = 2
net.ipv6.conf.eth0.use_tempaddr = 2
#net.ipv6.conf.<nic0>.use_tempaddr = 2
#net.ipv6.conf.<nicN>.use_tempaddr = 2
Note: 1 is addresses that incorporate MAC addresses into the IPv6 address, 2 is privacy addresses that generate what would be the MAC portion at random
It also goes against what the upstream default seems to be:
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob;f=Documentation/networking/ip-sysctl.txt;hb=HEAD#l1232
Those who are concerned about this issue are likely to already know how to enable it, and/or seek out the information.
In addition to my comments above, this change also goes against the recommendation of the relevant RFC [1], which states:
"Consequently, the use of temporary addresses SHOULD be disabled by default in order to minimize potential disruptions."
I recognize that this is an easy to change alter for the user, however as a default configuration I propose this change be reverted for 3 main reasons:
1) It introduces unexpected and transient behaviour.
2) It goes against upstream code in the interest of patching for privacy, which is generally not what Arch aims to do.
3) It goes against the RFC recommendation.
[1] https://tools.ietf.org/html/rfc4941#section-3.6
Therefore, I'll remove those two lines from sysctl.conf in SVN but, before pushing it in [testing], I'll see if we can move this file to the filesystem package - because I have no idea what sysctl.conf is doing in procps-ng... (Or am I missing something obvious?)