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When the left-pad debacle happened, I feared that people would conclude “dependencies are bad”. (Instead of the logical conclusion, which is “don’t allow dependencies to be deleted from package registries.”) That prediction turned out to be true. :(

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Not only deletion but more like immutability, and that is the problem for me of using github as the source of your dependency

kornel@mastodon.social

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and

In Cargo you can add `rev=hash` to git dependencies (and it's in Cargo.lock even if you don't)

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and

It's worth keeping in mind that Git hashes and signed commits / tags entirely depend on sha1 though. It's increasingly a bad idea to depend on any of it for security. Unfortunately, Git doesn't offer a solution and sources really need to be distributed in signed archive files.

kornel@mastodon.social

@kornelski

Jul 29, 2019

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@DanielMicay

There's no pre-image attack against SHA-1, not even close, not even theoretically close. Collisions are much more limited, and it's easy to detect files trying to use the only known weakness: github.blog/2017-03-20-sha

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That's why I said it's an increasingly bad idea to depend on it. It doesn't make sense to be building infrastructure today that depends on sha1 and has no real migration plan away from it. Creating a dependency on Git revisions or signed commits / tags today isn't a good plan.

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and

Something being known also doesn't imply that it's public. The reasoning that you're using is flawed. Publicly disclosed vulnerabilities or attacks aren't the full picture. It's known to have serious weaknesses and an accelerating pace of the disclosed attacks being improved.

kornel@mastodon.social

@kornelski

Jul 29, 2019

Replying to

@DanielMicay

This is irrational. If you assume everything is secretly crackable, then whatever alternative you propose — also is. In reality, public progress gives a ballpark idea of what is approaching possibility, and pre-image attacks are barely scratching MD4.

Daniel Micay

@DanielMicay

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@kornelski

It's not irrational. It's how cryptography and security are approached in general. Public progress does give a good idea of what's becoming practical for attackers with far more motivation and resources, which is why sha1 isn't considered secure and is considered a vulnerability.

6:41 PM · Jul 29, 2019Twitter Web App

kornel@mastodon.social

@kornelski

Jul 29, 2019

Replying to

@DanielMicay

SHA-1 for purposes depending on collision resistance is considered insecure. SHA-1 for purposes depending on preimage resistance is absolutely flawless for now and foreseeable future to the point you can bet your life on it.

kornel@mastodon.social

@kornelski

Jul 29, 2019

Replying to

@DanielMicay

The whole crypto fetish is useless when the practical attack scenario is someone putting malware straight into the source, and releasing it, because everyone just downloads the code (very well signed!) without reviewing it.

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I would not call avoiding depending on everyone having a strong password to be a crypto fetish. Taking an irresponsible and negligent approach is your prerogative and demonstrates the problem with trusting a bunch of developers, many of them treating security as an annoyance.

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