[Bitcoin-development] SPV client in pure JavaScript?

[Bitcoin-development] SPV client in pure JavaScript?

[Wendell]

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To those of you in the know about modern browser tech:

Does it seem at all conceivable that an SPV wallet could be built entirely in JavaScript? And if indeed it is within the realm of the possible, how would such a thing be safely distributed for use? Would a signed Chrome Plugin be an ideal vehicle?

-wendell

grabhive.com | twitter.com/grabhive | gpg: 6C0C9411


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Re: [Bitcoin-development] SPV client in pure JavaScript?

[Mike Hearn]

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JavaScript is turing complete so of course it can be done. The real
question you're asking is, can it be done in a web app? I think the answer
is I think "no" because web apps aren't allowed to make raw TCP socket
connections.

Now there may be a way around that by using browser-specific things like
extensions or "installable apps" which give your code greater access
permissions. This approach means you essentially use Chrome as your app
platform instead of a JVM, the assumption presumably being that more users
have Chrome than a JVM. The flip side is that users who don't would
probably balk at the idea of installing an entire browser in order to run a
wallet app, whereas a JVM can be bundled and the resulting app acts like
any other. I don't know of a convenient way to "statically link" Chrome
into a regular-looking application.

I personally wouldn't find such a design compelling. Whilst Java isn't
exactly a great language, JavaScript is significantly worse in virtually
all aspects. I don't understand why anyone would want to use JavaScript
outside the browser - you get less safety, less performance, fewer
features, less mature tools and so on. If the end result is an installable
app like any other, all you did is cripple yourself vs the competition
that's using languages/platforms designed for it.



On Fri, Aug 9, 2013 at 1:32 PM, Wendell <w@grabhive.com> wrote:

> To those of you in the know about modern browser tech:
>
> Does it seem at all conceivable that an SPV wallet could be built entirely
> in JavaScript? And if indeed it is within the realm of the possible, how
> would such a thing be safely distributed for use? Would a signed Chrome
> Plugin be an ideal vehicle?
>
> -wendell
>
> grabhive.com | twitter.com/grabhive | gpg: 6C0C9411
>
>
>
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Re: [Bitcoin-development] SPV client in pure JavaScript?

[Wendell]

Right, I'm not suggesting that we have this wallet in a web app, but rather precisely what you are talking about: using special browser features, and bundling it. I am fundamentally monoculture-opposed, but given Chrome's present installed base, that initial target makes sense to me, provided that we could have a one-click installation (as per normal, via the Chrome Store).

Chrome also has this "Native Client" plug-in: I know next to nothing about it, and this goes off the rails of the Subject, but perhaps an SPV implementation there could be a solution to the concerns you expressed?

-wendell

grabhive.com | twitter.com/grabhive | gpg: 6C0C9411

On Aug 9, 2013, at 1:48 PM, Mike Hearn wrote:

> JavaScript is turing complete so of course it can be done. The real question you're asking is, can it be done in a web app? I think the answer is I think "no" because web apps aren't allowed to make raw TCP socket connections.
> 
> Now there may be a way around that by using browser-specific things like extensions or "installable apps" which give your code greater access permissions. This approach means you essentially use Chrome as your app platform instead of a JVM, the assumption presumably being that more users have Chrome than a JVM. The flip side is that users who don't would probably balk at the idea of installing an entire browser in order to run a wallet app, whereas a JVM can be bundled and the resulting app acts like any other. I don't know of a convenient way to "statically link" Chrome into a regular-looking application.
> 
> I personally wouldn't find such a design compelling. Whilst Java isn't exactly a great language, JavaScript is significantly worse in virtually all aspects. I don't understand why anyone would want to use JavaScript outside the browser - you get less safety, less performance, fewer features, less mature tools and so on. If the end result is an installable app like any other, all you did is cripple yourself vs the competition that's using languages/platforms designed for it.

Re: [Bitcoin-development] SPV client in pure JavaScript?

[Mike Hearn]

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Code that runs inside NativeClient has the same access level as JavaScript
does. It's just a way to do things faster.

Distribution as a Chrome app via the Chrome store is a fine approach, as
long as people understand it's just an app platform like any other. It has
pros and cons that must be weighed up. For instance, Chrome for mobile
doesn't really do apps, at least not at the moment. Also, you're still
limited by what APIs Chrome exposes, which are a strict subset of what a
real OS provides.


On Fri, Aug 9, 2013 at 2:05 PM, Wendell <w@grabhive.com> wrote:

> Right, I'm not suggesting that we have this wallet in a web app, but
> rather precisely what you are talking about: using special browser
> features, and bundling it. I am fundamentally monoculture-opposed, but
> given Chrome's present installed base, that initial target makes sense to
> me, provided that we could have a one-click installation (as per normal,
> via the Chrome Store).
>
> Chrome also has this "Native Client" plug-in: I know next to nothing about
> it, and this goes off the rails of the Subject, but perhaps an SPV
> implementation there could be a solution to the concerns you expressed?
>
> -wendell
>
> grabhive.com | twitter.com/grabhive | gpg: 6C0C9411
>
> On Aug 9, 2013, at 1:48 PM, Mike Hearn wrote:
>
> > JavaScript is turing complete so of course it can be done. The real
> question you're asking is, can it be done in a web app? I think the answer
> is I think "no" because web apps aren't allowed to make raw TCP socket
> connections.
> >
> > Now there may be a way around that by using browser-specific things like
> extensions or "installable apps" which give your code greater access
> permissions. This approach means you essentially use Chrome as your app
> platform instead of a JVM, the assumption presumably being that more users
> have Chrome than a JVM. The flip side is that users who don't would
> probably balk at the idea of installing an entire browser in order to run a
> wallet app, whereas a JVM can be bundled and the resulting app acts like
> any other. I don't know of a convenient way to "statically link" Chrome
> into a regular-looking application.
> >
> > I personally wouldn't find such a design compelling. Whilst Java isn't
> exactly a great language, JavaScript is significantly worse in virtually
> all aspects. I don't understand why anyone would want to use JavaScript
> outside the browser - you get less safety, less performance, fewer
> features, less mature tools and so on. If the end result is an installable
> app like any other, all you did is cripple yourself vs the competition
> that's using languages/platforms designed for it.
>

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Re: [Bitcoin-development] SPV client in pure JavaScript?

[Mike Hearn]

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Oh, I forgot to make it clear - Chrome apps/extensions can make raw TCP
socket connections:

   http://blog.chromium.org/2012/11/introducing-tcp-listen-new-api-for.html

You would do it as a packaged app:
http://developer.chrome.com/apps/about_apps.html  because then they're a
lot more similar to native apps (they get their own windows, run offline,
etc).

But these aren't standard APIs. They're all Chrome extensions. I doubt
HTML5 will support USB access anytime soon, for instance, but packaged apps
do.



On Fri, Aug 9, 2013 at 2:10 PM, Mike Hearn <mike@plan99.net> wrote:

> Code that runs inside NativeClient has the same access level as JavaScript
> does. It's just a way to do things faster.
>
> Distribution as a Chrome app via the Chrome store is a fine approach, as
> long as people understand it's just an app platform like any other. It has
> pros and cons that must be weighed up. For instance, Chrome for mobile
> doesn't really do apps, at least not at the moment. Also, you're still
> limited by what APIs Chrome exposes, which are a strict subset of what a
> real OS provides.
>
>
> On Fri, Aug 9, 2013 at 2:05 PM, Wendell <w@grabhive.com> wrote:
>
>> Right, I'm not suggesting that we have this wallet in a web app, but
>> rather precisely what you are talking about: using special browser
>> features, and bundling it. I am fundamentally monoculture-opposed, but
>> given Chrome's present installed base, that initial target makes sense to
>> me, provided that we could have a one-click installation (as per normal,
>> via the Chrome Store).
>>
>> Chrome also has this "Native Client" plug-in: I know next to nothing
>> about it, and this goes off the rails of the Subject, but perhaps an SPV
>> implementation there could be a solution to the concerns you expressed?
>>
>> -wendell
>>
>> grabhive.com | twitter.com/grabhive | gpg: 6C0C9411
>>
>> On Aug 9, 2013, at 1:48 PM, Mike Hearn wrote:
>>
>> > JavaScript is turing complete so of course it can be done. The real
>> question you're asking is, can it be done in a web app? I think the answer
>> is I think "no" because web apps aren't allowed to make raw TCP socket
>> connections.
>> >
>> > Now there may be a way around that by using browser-specific things
>> like extensions or "installable apps" which give your code greater access
>> permissions. This approach means you essentially use Chrome as your app
>> platform instead of a JVM, the assumption presumably being that more users
>> have Chrome than a JVM. The flip side is that users who don't would
>> probably balk at the idea of installing an entire browser in order to run a
>> wallet app, whereas a JVM can be bundled and the resulting app acts like
>> any other. I don't know of a convenient way to "statically link" Chrome
>> into a regular-looking application.
>> >
>> > I personally wouldn't find such a design compelling. Whilst Java isn't
>> exactly a great language, JavaScript is significantly worse in virtually
>> all aspects. I don't understand why anyone would want to use JavaScript
>> outside the browser - you get less safety, less performance, fewer
>> features, less mature tools and so on. If the end result is an installable
>> app like any other, all you did is cripple yourself vs the competition
>> that's using languages/platforms designed for it.
>>
>
>

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Re: [Bitcoin-development] SPV client in pure JavaScript?

[Wendell]

"Packaged app pages always load locally. This allows apps to be less dependent on the network. Once a user installs an app, they have full control over the app's lifecycle. Apps open and close quickly, and the system can shut apps down at any time to improve performance. Users can fully uninstall apps."

Does this mean that upon install, a nice, icon-emblazoned package will drop into my /Applications folder on a Mac, or in my Windows Start menu, etc... Or are packaged apps always launched and maintained from within Chrome itself?

Provided that the technical stuff could be made to work within the context of the more limited API, this certainly seems like an interesting, user-friendly way to distribute a Bitcoin wallet!

-wendell

grabhive.com | twitter.com/grabhive | gpg: 6C0C9411

On Aug 9, 2013, at 2:14 PM, Mike Hearn wrote:

> Oh, I forgot to make it clear - Chrome apps/extensions can make raw TCP socket connections:
> 
>   http://blog.chromium.org/2012/11/introducing-tcp-listen-new-api-for.html
> 
> You would do it as a packaged app: http://developer.chrome.com/apps/about_apps.html  because then they're a lot more similar to native apps (they get their own windows, run offline, etc). 
> 
> But these aren't standard APIs. They're all Chrome extensions. I doubt HTML5 will support USB access anytime soon, for instance, but packaged apps do.

Re: [Bitcoin-development] SPV client in pure JavaScript?

[Chris Double]

On Sat, Aug 10, 2013 at 12:14 AM, Mike Hearn <mike@plan99.net> wrote:
> Oh, I forgot to make it clear - Chrome apps/extensions can make raw TCP
> socket connections:
>
>    http://blog.chromium.org/2012/11/introducing-tcp-listen-new-api-for.html

There's a Raw Sockets proposal at the W3C that provides TCP sockets:

<http://www.w3.org/2012/sysapps/raw-sockets/>

Firefox OS has an API that is being discussed as part of that:

<https://developer.mozilla.org/en-US/docs/WebAPI/TCP_Socket>

So there's a possibility of a standardized approach in the future.

Chris.
-- 
http://www.bluishcoder.co.nz

Re: [Bitcoin-development] SPV client in pure JavaScript?

[Jeff Garzik]

On Fri, Aug 9, 2013 at 7:32 AM, Wendell <w@grabhive.com> wrote:
> To those of you in the know about modern browser tech:
>
> Does it seem at all conceivable that an SPV wallet could be built entirely in JavaScript? And if indeed it is within the realm of the possible, how would such a thing be safely distributed for use? Would a signed Chrome Plugin be an ideal vehicle?

Certainly.  BitPay is working on such a wallet:
https://github.com/jgarzik/wally

wally uses node.js JavaScript, and not browser JavaScript, so not
exactly what you're talking about...

-- 
Jeff Garzik
Senior Software Engineer and open source evangelist
BitPay, Inc.      https://bitpay.com/

Re: [Bitcoin-development] SPV client in pure JavaScript?

[Wendell]

No, it's not -- but that's certainly very cool to see Jeff.

How is BitPay going to put this to use?

-wendell

grabhive.com | twitter.com/grabhive | gpg: 6C0C9411

On Aug 9, 2013, at 3:08 PM, Jeff Garzik wrote:

> Certainly.  BitPay is working on such a wallet:
> https://github.com/jgarzik/wally
> 
> wally uses node.js JavaScript, and not browser JavaScript, so not
> exactly what you're talking about...

Re: [Bitcoin-development] SPV client in pure JavaScript?

[Jeff Garzik]

On Fri, Aug 9, 2013 at 1:58 PM, Wendell <w@grabhive.com> wrote:
> No, it's not -- but that's certainly very cool to see Jeff.
>
> How is BitPay going to put this to use?

Well, "wally" is just a demo application, a command line client to
prove a technology.

The main development is in places like "node-libcoin", where a wallet
platform is being developed.  While maintaining a strong commitment to
the blockchain engine side of bitcoind, BitPay has enterprise wallet
needs that do not necessarily mesh well with the standard bitcoind
wallet.  Multi-sig, P2SH and other advanced features are key to the
future use of bitcoin in large enterprises.  Managers, CEOs and other
functionaries at a corporation may each have their own wallets /
keyrings, and cooperate to sign large value, high security bitcoin
multi-sig transactions, for example.

-- 
Jeff Garzik
Senior Software Engineer and open source evangelist
BitPay, Inc.      https://bitpay.com/