[HN Gopher] A Criticism of JavaScript Cryptography
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A Criticism of JavaScript Cryptography
Author : ementally
Score : 20 points
Date : 2023-03-05 18:47 UTC (4 hours ago)
(HTM) web link (blog.bren2010.io)
(TXT) w3m dump (blog.bren2010.io)
| codeflo wrote:
| This seems to argue that accessing a web app (assuming an
| important piece of software that handles private encrypted data)
| is no less secure than loading software from a package
| repository, because a web server requesting the JavaScript and a
| software updater loading binary code from a server is
| structurally identical.
|
| The obvious response to this is offline signatures: For package
| managers, app stores, updaters and the like, the integrity of the
| update server itself doesn't really matter, because the installer
| verifies a cryptographic signature from an offline key.
|
| This argument is acknowledged, but seems to be dismissed without
| a real explanation:
|
| > More astutely, there's also the distinction that either a file
| system compromise or a key compromise is required to serve
| malicious code to users with TLS, but software repositories can
| be architected such that a key compromise is required, through
| the implementation of offline keys. Despite this, though, there
| are several examples of secure software repositories that
| successfully use TLS. This isn't a grave concern (and they
| probably won't be converting soon) because the decision to use
| offline keys is palliative, at best, and only marginally
| increases a system's level of security.
|
| > However, I openly concede that there are cases where a software
| repository can offer a higher level of security than a browser is
| currently capable of. I plan to discuss this later.
|
| AFAICT, this "later" doesn't happen in this article, though I
| might have missed something. I really don't see why offline
| signatures are only "palliative". Web servers are hacked all the
| time, DNS misconfigurations happen, but organizations losing
| control of their software signature keys is comparatively rare.
| Why would you give up a very effective level of defense if it's
| so easily available?
| dgl wrote:
| I'd really like to see something like
| https://engineering.fb.com/2022/03/10/security/code-verify/
| become a more standard part of browsers. i.e. a standard way to
| go from sub-resource integrity to "full integrity".
|
| Having it as an extension just moves the weak point to the
| extension update mechanism.
|
| Of course apps can just distribute themselves as an extension
| which is probably the best compromise right now and something
| most web based password managers for example already offer.
| franky47 wrote:
| > Do "secure keystores" just not exist?
|
| Probably not if we consider threat models evolving in the same
| userspace as where they're implemented (eg as cited: keyloggers
| and malicious native programs).
|
| HSMs may provide an entrypoint to the "root of secrecy" problem,
| though the way they interface with the system now becomes the
| single point of defense.
| woodruffw wrote:
| (2014).
|
| This is a response to Matasano's "JavaScript Cryptography
| Considered Harmful"[1], except Matasano no longer exists and the
| link in the post 404s.
|
| Archived[2].
|
| [1]: https://matasano.com/articles/javascript-cryptography/
|
| [2]:
| https://web.archive.org/web/20120414231547/https://matasano....
| thayne wrote:
| Ah, the reference to http 3.0 not existing for hundreds of
| years makes a lot more sense knowing it is from 2014
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