Add -uaappend option to append a literal string to user agent

luke-jr commented at 2:28 am on June 11, 2020: member

This can be used by other software that controls the node instance (eg, ABCore)

luke-jr force-pushed on Jun 11, 2020

DrahtBot added the label Tests on Jun 11, 2020

laanwj commented at 5:08 pm on June 11, 2020: member

Can you show some usage examples and resulting UA string?

Also: For what it’s worth in web browsers there’s currently a trend toward simplifying user agents, creating less variants instead of more. Mostly for privacy reasons. Is signalling this extra information in the user agent useful for the user of the node, or is it simply for statistics for the developers?

MarcoFalke commented at 5:22 pm on June 11, 2020: member

Slightly tend to NACK. Might as well put in the OS, whether the full node is controlled by the GUI, …

Sometimes remote attacks can only be exploited in a specific environment, putting that specific environment into the ua and sending it to the attacker seems counter productive.

MarcoFalke added the label P2P on Jun 11, 2020

MarcoFalke removed the label Tests on Jun 11, 2020

luke-jr commented at 9:46 pm on June 11, 2020: member

Can you show some usage examples and resulting UA string?

-uaappend ABCore:1.1.1 could produce /Satoshi:0.20.0/ABCore:1.1.1/

Sometimes remote attacks can only be exploited in a specific environment, putting that specific environment into the ua and sending it to the attacker seems counter productive.

You could argue for removing the UA entirely. But so long as it’s there, there’s no reason to stop other people from using it as intended. (Nobody is forcing anyone to use this if they don’t want to.)

kristapsk commented at 9:56 pm on June 11, 2020: contributor

I agree with @luke-jr here, concept ACK.

Might as well put in the OS, whether the full node is controlled by the GUI,

This is different, it’s something user puts there if he wants to (example - “UASF”), not something that gives out some information about your system by default.

luke-jr commented at 10:14 pm on June 11, 2020: member

Note we already have uacomment for user stuff. This would be just for applications built on top of Core.

MarcoFalke commented at 10:20 pm on June 11, 2020: member

Giving a footgun to a user is less bad than giving a footgun to applications built on top of Core. Explicitly offering the option makes it seem “officially supported” or even encouraged for applications to use it.

luke-jr commented at 10:56 pm on June 11, 2020: member

How about if we hide it behind -help-debug?

MarcoFalke commented at 11:09 pm on June 11, 2020: member

I simply don’t see the use case to tell malicious remote peers that you are running on an Android system.

If there was a use case, then other operating systems (and other system information) should also be put in there, not only Android.

luke-jr commented at 0:04 am on June 12, 2020: member

ABCore is not an operating system.

A better example might be Wasabi, but I’m not sure they support Core at the moment.

Or Armory, perhaps.

DrahtBot commented at 1:46 pm on July 21, 2020: member

The following sections might be updated with supplementary metadata relevant to reviewers and maintainers.

Conflicts

Reviewers, this pull request conflicts with the following ones:

#17783 (util: Fix -norpcwhitelist, -norpcallowip, and similar corner case behavior by ryanofsky)
#17580 (refactor: Add ALLOW_LIST flags and enforce usage in CheckArgFlags by ryanofsky)

If you consider this pull request important, please also help to review the conflicting pull requests. Ideally, start with the one that should be merged first.

DrahtBot added the label Needs rebase on Jul 30, 2020

Add -uaappend option to append a literal string to user agent

This can be used by other software that controls the node instance (eg, ABCore)

71dde00b2d

QA: Test -uaappend e9d0d92490

luke-jr force-pushed on Aug 20, 2020

luke-jr commented at 3:49 pm on August 20, 2020: member

Rebased

DrahtBot removed the label Needs rebase on Aug 20, 2020

fanquake commented at 8:58 am on April 12, 2021: member

I can’t see much support for adding this, and for what it’s worth I’m also a ~0/NACK. I don’t think there’s heaps of value to adding a “not really supported” hidden option to allow other pieces of software to add more information to our user agent. Also the examples given don’t seem very convincing:

ABCore

Is this still actively developed / maintained? Seems like the website no longer exists, and the repository has a bunch of spam issues open / hasn’t seen any updates for ~18 months. Has it moved somewhere else?

A better example might be Wasabi, but I’m not sure they support Core at the moment.

As mentioned, this software doesn’t actually support Bitcoin Core, for reasons unrelated this this, so this seems like a poor argument for adding a feature for it to use?

Or Armory, perhaps.

Do we know if this is something that Armory actually wants/would use?

In any case, I’m going to close this for now.

fanquake closed this on Apr 12, 2021

laanwj commented at 10:14 am on April 12, 2021: member

don’t think there’s heaps of value to adding a “not really supported” hidden option to allow other pieces of software to add more information to our user agent.

I agree 100%. Also the privacy zeitgeist seems to be to strip as much as possible from user agents and other publicly visible software-identifying information, not to add more specifics.

DrahtBot locked this on Aug 18, 2022

Add -uaappend option to append a literal string to user agent #19242

Conflicts