[bisq-network/bisq] Support setting one or more user-defined block explorers (#4371)

[Chris Beams]

Currently Bisq supports a fixed set of options for which block explorer to use when following links in the application to Bitcoin transactions and addresses. These options are hard-coded at https://github.com/bisq-network/bisq/blob/release/v1.3.6/core/src/main/java/bisq/core/user/Preferences.java#L80-L99 and show up in the application here:

<img width="1312" alt="image" src="https://user-images.githubusercontent.com/301810/88283182-39f59c80-cceb-11ea-8aa1-1bc6c3154570.png">

Use of any centralized block explorer is a known privacy risk, because the service may be logging queries, including the user's IP address and other unique information and linking them to the Bitcoin addresses and/or transactions being queried. This risk can be mitigated by using a Tor-based block explorer service, but such use is still not ideal. See [these](https://en.bitcoin.it/Privacy#Blockchain_explorer_websites) [two](https://en.bitcoin.it/Privacy#Bad_privacy_example_-_Using_a_blockchain_explorer) sections of @chris-belcher's Privacy article in the Bitcoin Wiki's for more details.

The ideal approach is to use a private block explorer, i.e. one running on one's own local network that queries one's own Bitcoin Core node. Doing so eliminates the risk of being tracked by other parties as no other parties are involved.

It is easy enough to add one's own block explorer by modifying `Preferences.java` (see link above), but ideally one would be able to specify one or more custom block explorer URLs in the `Settings->Preferences` screen above. A precedent for this kind of configuration functionality can be found in the `Settings->Network Info` screen:

<img width="1312" alt="image" src="https://user-images.githubusercontent.com/301810/88284301-79bd8380-cced-11ea-9590-ef82a3c1fa81.png">

Note how, if the user selects the 'Use custom Bitcoin Core nodes' radio button, they can then provide one or more custom node addresses in the input field below. The interaction would need to be different in the case of specifying custom block explorers, because each block explorer requires two URL templates, one for transaction lookups and one for address lookups, but this existing, somewhat similar configuration functionality may be useful as a starting point when considering how to implement this feature.

While it might be easiest to support adding just one custom block explorer, it would be ideal to allow specifying multiple of them, because in the case of an explorer running on one's local network, one might wish to access it via clearnet http when at home and via Tor when remote. This would require specifying two sets of URLs. And of course the user might want to specify any number of additional custom explorer services.


-- 
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/bisq-network/bisq/issues/4371
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bisq.network/pipermail/bisq-github/attachments/20200723/80308396/attachment.html>