Support Unstoppable Domains via DoH behind a feature flag

[yrliou]

Support the name resolution of unstoppable domains via https://resolver.unstoppable.io/dns-query endpoint when the feature is enabled in brave://flags and user set the resolve method to public DoH server.

Settings

Under brave://settings/extensions, a new dropdown box setting for unstoppable domain resolution will be added, and the default value will be “Ask”.

Onboarding

(Above screenshot is an initial version of the interstitial page, it will be updated to match design spec.)
When the unstoppable domain resolution setting is “Ask”, an interstitial page will be shown when users try to visit .crypto domains for users to opt in. If users choose to proceed, the setting will be changed to “Public DNS over HTTPS server”, and the page will be reloaded and resolved using the DNS gateway, future navigations to .crypto domains will be resolved using the same DNS gateway. If users click “Don’t ask again”, the setting will be set to disabled.

DNS gateway

When a user input an address with a known TLD from unstoppable domains (ex: .crypto domains) in the browser URL bar, the domain name will be resolved through a DNS gateway which supports the resolution of unstoppable domains. Brave will use https://resolver.unstoppable.io/dns-query endpoint provided by Unstoppable Domains, which is a proxy to https://eth.resolver.cloudflare-eth.com/dns-query, as the DNS gateway. It will be responsible for making calls to Ethereum smart contracts using the Ethereum JSON RPC to resolve the address. This DNS gateway will be added into the browser's DNS over HTTPS providers, but will only be used for resolving known TLD from Unstoppable Domains. Because this method requires DNS over HTTPS support, we will not resolve Unstoppable Domains if DoH is disabled either by user or by policy regardless of the value of user setting for Unstoppable Domain resolution.
Using DNS gateway is a simpler method which could be used by default for all our users without introducing overhead of making calls to Ethereum, and is using the protocols (HTTP, DNS) which are well supported by the browser. However, it does come with a downside that the decentralization is decreased due to the introduction of the hosted DNS gateway, so in the future we will also provide the option to resolve via ethereum directly to users.

Recognizing TLDs from unstoppable domains

In order to make URLs with known TLDs from unstoppable domains to be categorized as URL when users input them in the location bar, we will treat these TLDs as known TLDs from the public suffix list. With this, the first entry in the dropdown list will be URL as shown below.

[stephendonner]

Verified FIXED using nightly with the testplan from brave/brave-core#7702 on

Brave	1.23.19 Chromium: 89.0.4389.72 (Official Build) nightly (x86_64)
Revision	3f345f156bfd157bd1bea06310e55f3fb2490359-refs/branch-heads/4389@{#1393}
OS	macOS Version 11.2.2 (Build 20D80)

1. Open Brave and visit brave.crypto, it should show error page saying This site can’t be reached.

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2. Go to settings, search for unstoppable, there should be no unstoppable domains resolve method setting.

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3. Go to brave://flags and search for unstoppable and enable the feature flag.

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4. Restart browser and go to brave.crypto should now should the interstitial for users to opt-in unstoppable domains support.

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5. Click Disable, should now see site can't be reached and Method to resolve unstoppable domains in brave://settings should now be Disabled.

screenshots

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6. Change the resolve method setting back to ask and visit brave.crypto again.

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7. Opt-in interstitial should be shown again, and this time click Proceed using Cloudflare server.
8. Page should be loaded now. (Note that there will be a brief moment that it is showing site is not reached while the page is loading, this is a known and will be addressed in a new issue.)

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9. Method to resolve unstoppable domains in brave://settings should now be Public DNS over HTTP server.

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10. Open a new tab and visit brad.crypto, page should be loaded normally without any interstitial pages.

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Additionally, I filed #14478 for the cropped Public DNS over HTTPS serv text in the select widget.

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Verification passed on

Brave | 1.22.65 Chromium: 89.0.4389.90 (Official Build) (64-bit)
-- | --
Revision | 62eb262cdaae9ef819aadd778193781455ec7a49-refs/branch-heads/4389@{#1534}
OS | Windows 10 OS Version 2004 (Build 19041.867)

• Verified the test plan from Support Unstoppable Domains via DNS over HTTPS behind a feature flag brave-core#7702

1. Open Brave and visit brave.crypto and ensured opt-in interstitial page is opened (as per the issue description Do not show opt-in page for decentralized DNS support in OTR contexts #14488 (comment))

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2. Go to settings, search for unstoppable, there is Method to resolve Unstoppable Domains settings set to Ask by default

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5. Ensured that open http://brave.crypto/ in normal tab is showing up This site can’t be reached page when Method to resolve Unstoppable Domains is set to Disable in brave://settings

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6,7 and 8. Set the Method to resolve Unstoppable Domains is set to Ask again in brave://settings and ensured reload the page http://brave.crypto/ opens up an interstitial page and click on proceed opens up the http://brave.crypto/ page

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9. Ensured Method to resolve unstoppable domains in brave://settings is set to Public DNS over HTTP server

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10. Ensured open a new tab and visit brave.crypto page loads normally without any interstitial pages.

• Encountered 'Public DNS over HTTP server" text in Settings select widget is cropped #14478

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Verification passed on

Brave	1.22.66 Chromium: 89.0.4389.90 (Official Build) (64-bit)
Revision	62eb262cdaae9ef819aadd778193781455ec7a49-refs/branch-heads/4389@{#1534}
OS	Ubuntu 18.04 LTS

• Verified the test plan from Support Unstoppable Domains via DNS over HTTPS behind a feature flag brave-core#7702

1. Open Brave and visit brave.crypto and ensured opt-in interstitial page is opened (as per the issue description Do not show opt-in page for decentralized DNS support in OTR contexts #14488 (comment))

screenshot

2. Go to settings, search for unstoppable, there is Method to resolve Unstoppable Domains settings set to Ask by default

screenshot

5. Ensured that open http://brave.crypto/ in normal tab is showing up This site can’t be reached page when Method to resolve Unstoppable Domains is set to Disable in brave://settings

screenshot

6,7 and 8. Set the Method to resolve Unstoppable Domains is set to Ask again in brave://settings and ensured reload the page http://brave.crypto/ opens up an interstitial page and click on proceed opens up the http://brave.crypto/ page

screenshot

9. Ensured Method to resolve unstoppable domains in brave://settings is set to Public DNS over HTTP server

screenshot

10. Ensured open a new tab and visit brave.crypto page loads normally without any interstitial pages.