Starting in late September 2019, DNS over HTTPS (DoH) is going to be rolled out to Firefox users in the United States.
DNS over HTTPS encrypts DNS requests to improve security and privacy of these requests. Most DNS requests happen in the open currently; anyone listening to the traffic gets records of site and IP addresses that were looked up while using an Internet connection among other things.
DoH encrypts the traffic and while that looks good on first glance, it needs to be noted that TLS still gives away the destination in plaintext.
One example: Internet providers may block certain DNS requests, e.g. when they have received a court order to block certain resources on the Internet. It is not the best method to prevent people from accessing a site on the Internet but it is used nevertheless.
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DoH is excellent against censorship that uses DNS manipulation.
Mozilla started to look into the implementation of DoH in Firefox in 2018. The organization ran a
controversial Shield study in 2018 to gather data that it needed for the planned implementation of the feature. The study was controversial because Mozilla used the third-party Cloudflare as the DNS over HTTPS service which meant that all user traffic flowed through the Cloudflare network.
Mozilla revealed in April 2019 that its plan to
enable DoH in Firefox had not changed. The organization created a list of policies that DoH providers had to conform to if they wanted their service to be integrated in Firefox.
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In "What's next in making encrypted DNS-over-HTTPS the Default", Mozilla confirmed that it would begin to enable DoH in Firefox starting in late September 2019. The feature will be enabled for some users from the United States and Mozilla plans to monitor the implementation before DoH is rolled out to a larger part of the user base and eventually all users from the United States.
We plan to gradually roll out DoH in the USA starting in late September. Our plan is to start slowly enabling DoH for a small percentage of users while monitoring for any issues before enabling for a larger audience. If this goes well, we will let you know when we’re ready for 100% deployment.
While DNS over HTTPS will be the default for the majority of Firefox installations in the United States, it won't be enabled for some configurations:
- If parental controls are used, DoH won't be enabled provided that Mozilla detects the use correctly.
- Enterprise configurations are respected as well and DoH is disabled unless "explicitly enabled by enterprise configuration".
- Fall back option if DNS issues or split horizon configuration cause lookup failures.
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Network administrations
may configure their networks in the following way to highlight to Firefox that the network is unsuitable for DoH usage:
DNS queries for the A and AAAA records for the domain “use-application-dns.net†must respond with NXDOMAIN rather than the IP address retrieved from the authoritative nameserver.
How to block DNS over HTTPS
You have two options when it comes to DoH in Firefox. You can change the default provider -- Cloudflare is the default -- to
another provider (for whatever reason) or block the entire feature so that it won't be used.
If you don't want to use it, set the value of network.trr.mode to 5 on about:config.
Now You: What is your take on DoH and Mozilla's implementation?
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Summary
Article Name
Mozilla plans to roll out DNS over HTTPS to US users in late September 2019
Description
Starting in late September 2019, DNS over HTTPS (DoH) is going to be rolled out to Firefox users in the United States.
Author
Martin Brinkmann
Publisher
Ghacks Technology News
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Comments
Some VPN services roll their own DNS resolvers, so there’s yet another option to consider. If you’re using a VPN, using the VPN provider’s own DNS resolver will usually give you the best performance (slightly less latency) since your DNS query will not need to bounce to another location before going back through your VPN. (This is all assuming you don’t have some kind of DNS leak in the chain. There are various sites which allow you to test for DNS leaks like dnsleaktest dot com.)
> Mass surveillance is a thing. And in post-Snowden times, you can’t even say it’s a “tinfoil hat conspiracy theoryâ€.
What are advantages / disadvantages
over Google’s DNS servers: (8.8.8.8, 8.8.4.4).
I assume they will not make the change with a update (no updates planned for the rest of September), but instead use some kind of remote control over Firefox. I may not even get any notification of the change.
That would mean I would be browsing without the blocks in the hosts file, without knowing it.
This is why I do not like software makers having so much control over the software I use.
It is a security problem.
Mozilla says DoH is a privacy feature, yet they do not care enough about security (privacy), or they would have thought about this problem and built the DoH feature to use the host file.
network.security.esni.enabled <-set to true
– Firefox’s Policy Templates (I now manage them manually but there is the excellent ‘Enterprise Policy Generator’ extension as a front-end) sets network.trr.mode set to 5 when ‘Disable DNS over HTTPS’ is checked, which is relevant.
DNS-over-HTTP/2 is easier to deploy, as it can be served as a web page. But certificate management can be tricky.
dnscrypt-proxy supports both protocols. Unless one of them gives you systematic issues due to your ISP blocking it, you should just leave them both enabled. dnscrypt-proxy will try all the configured resolvers, and use the fastest ones no matter what the protocol is.
DNS-over-TLS is useless. It has zero benefits over these, so it is not implemented.”
Mainly due to the third point.
⇒ “I really really do NOT want to use Firefox’s DNS-over-HTTPS.”
⇒ “What is network.trr.mode or DNS-over-HTTPS ? Oh nevermind, I don’t care anyway.” — ie. probably the majority of users
⇒ use DNS-over-HTTP only, don’t (immediately) fallback to using host system’s DNS resolver
⇒ or: full web domain of your preferred public DNS resolver
⇒ default: https://mozilla.cloudflare-dns.com/dns-query
⇒ or: IP address of your preferred public DNS resolver
⇒ IP address is for primary fallback, in case the specified DNS resolver’s web domain can’t be resolved. If left blank, Firefox will fallback to using the host system’s DNS resolver (which may or may not be acceptable to you for privacy & security reasons).
1 – Race native against TRR. Do them both in parallel and go with the one that returns a result first.
2 – TRR first. Use TRR first, and only if the name resolve fails use the native resolver as a fallback.
3 – TRR only. Only use TRR. Never use the native (after the initial setup).
4 – Shadow mode. Runs the TRR resolves in parallel with the native for timing and measurements but uses only the native resolver results.
5 – Explicitly off. Also off, but selected off by choice and not default.
* TRR = Trusted Recursive Resolver
* 0=off, 1=race (removed in FF69), 2=TRR first, 3=TRR only,
* 4=race for stats but always use native result (removed in FF69)
* [WARNING] DoH bypasses hosts and gives info to yet another party (e.g. Cloudflare)
* [1] https://www.ghacks.net/2018/04/02/configure-dns-over-https-in-firefox/
* [2] https://hacks.mozilla.org/2018/05/a-cartoon-intro-to-dns-over-https/ ***/
// user_pref(“network.trr.mode”, 0);
// user_pref(“network.trr.bootstrapAddress”, “”);
// user_pref(“network.trr.uri”, “”);
– In order to use it, you have to use the default TRR (or specify one): and it is not my place to decide who someone else should connect to
– DoH has uses. I am neither for nor against it: Hence, it will be inactive .. i.e neutral. I only want to provide the information so users are informed and can make their own decisions
> You removed documentation on how to disable in depth Google safebrowsing, and now that ? Have you lost it ?
> wishing that it doesn’t shrink due to a policy which would consider that only essential settings
* [1] resource://app/defaults/permissions ***/
user_pref(“permissions.manager.defaultsUrlâ€, “â€);
https://www.reddit.com/r/firefox/comments/792209/psa_use_hidden_pref/
https://bugzilla.mozilla.org/show_bug.cgi?id=1310082#c24 & comment 25
https://www.ghacks.net/2017/10/27/how-to-enable-firefox-webextensions-on-mozilla-websites/
(end of Quote [Thorin-Oakenpants]).
# The file-format is strict:
# * matchtype \t type \t permission \t host
# * “origin” should be used for matchtype, “host” is supported for legacy reasons
# * type is a string that identifies the type of permission (e.g. “cookie”)
# * permission is an integer between 1 and 15
# See nsPermissionManager.cpp for more…
origin uitour 1 https://www.mozilla.org
origin uitour 1 https://support.mozilla.org
origin uitour 1 https://addons.mozilla.org
origin uitour 1 https://discovery.addons.mozilla.org
origin uitour 1 about:home
origin uitour 1 about:newtab
origin install 1 https://addons.mozilla.org
origin install 1 https://testpilot.firefox.com
origin remote-troubleshooting 1 https://input.mozilla.org
origin remote-troubleshooting 1 https://support.mozilla.org (end of Quote [Mike Chapman])
# The file-format is strict:
# * matchtype \t type \t permission \t host
# * “origin” should be used for matchtype, “host” is supported for legacy reasons
# * type is a string that identifies the type of permission (e.g. “cookie”)
# * permission is an integer between 1 and 15
# See nsPermissionManager.cpp for more…
origin uitour 1 https://www.mozilla.org
origin uitour 1 https://self-repair.mozilla.org
origin uitour 1 https://support.mozilla.org
origin uitour 1 https://addons.mozilla.org
origin uitour 1 https://discovery.addons.mozilla.org
origin uitour 1 about:home
Are you _sure_ that DNS over HTTPS means the hosts file is bypassed/useless? As I said, my primary DNS server is Cloudflare’s 1.1.1.1 (which may imply DoH?), but my impression was that, at the same time, my carefully crafted hosts file is still active. I’m not certain, however. Can anybody clarify this?
Firefox does not use the hosts file when it uses DNS over HTTPS (DoH).
You can check this yourself adding this line to to the hosts file:
0.0.0.0 http://www.bing.com
Next, try to visit http://www.bing.com in Firefox. You wil get a error as it is blocked in the host file.
Next, enable DoH in Firefox. Options -> General -> Network Settings ->Settings.
Turn on the “Enable DNS over HTTPS†option.
Restart Firefox and try to go to http://www.bing.com. Now you will reach the site.
So the hosts file is no longer used.
HTTPS does stop your ISP from seeing which webpage on a website you are viewing.
But you can prevent such attacks by entering the IP addresses of all critical websites into your hosts file. The hosts file is checked first before using DNS.
So this is a bad move by Mozilla by making it the default:
They were warned about it too, but choose to ignore the problem:
https://bugzilla.mozilla.org/show_bug.cgi?id=1511643 and https://bugzilla.mozilla.org/show_bug.cgi?id=1453207.
Yes, in Firefox once it’s set, all DNS requests go straight to Cloudflare. Now if you configure 1.1.1.1 in your network card as the preferred DNS, that is different. No DoH just standard DNS and the HOSTS file will be checked first by the OS.
Now it seems to be gone but do not worry google solves this, they will implement this and keep selling your data in chromium too with 8.8.8.8 even if they will be fined again for that.
Click on the 3 lying dashes in the upper right corner
The address bar now says: Firefox about: preferences
In the first menu item, “General” scroll all the way down, until you reach “Network Settings”.
There you click on “Settings”.
And in the window that opens (connection settings), tick the box: “Enable DNS over HTTPS”.
Click on “OK”. For your ISP (Internet Service Provider) you have suddenly become “invisible”.
https://www.youtube.com/watch?v=1–MWzrdwxM
1 – [Race] Query both the system & Firefox’s DNS-over-HTTPS resolvers in parallel, & let Firefox select either one based on which returns faster DNS query responses
https://wiki.mozilla.org/Trusted_Recursive_Resolver#network.trr.mode
1 – Reserved (used to be Race mode)
4 – Reserved (used to be Shadow mode)