Key import and export cli commands

[rendaw]

Fixes #4240

This modifies ipfs key generate to add an export flag, and adds ipfs key export ipfs key import ipfs key identify. The latter prints the public key fingerprint for an exported key.

I ran some tests, but I had issues with running the tests locally so I'm hoping that some CI will run the tests for me if I make a PR.

I mentioned some concerns in the linked issue. Also not sure how to handle the private key in the sharness tests -- I could move that into a variable, but I didn't see precedent for that so I kept it inline for the first revision.

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[rendaw]

Are the tests private? I'm getting redirected to login when I try to look at sharness.

[aschmahmann]

Thanks @rendaw, I'll try and take a look at this PR next week. It looks like the CI results are publicly available via the green/red marks but that the runs themselves are not publicly available.

[rendaw]

Awesome, thanks! Also FWIW I included the kitchen sink here, I figured it's easier to add stuff early and remove it later than add stuff later.

[aschmahmann]

Thanks @rendaw for the work. A few of the kitchen sink things to remove here are:

• ipfs key gen should not allow exporting keys
• ipfs key identify doesn't seem super useful right now

I can try and do some pushes to this branch and see if we can push it over the finish line.

[rendaw]

Great, thanks! Removed the export option from gen.

[aschmahmann]

@rendaw I switched us from using base58btc encoded strings to just sending the raw bytes over the wire and working with files.

While in the future it's pretty easy for us to add new base encodings to import/export (e.g. --type=raw/multibase) it's actually pretty painful for us to allow for imports to be strings OR files.

I went with files over strings here as it seems likely to me that people will want to ultimately store these blobs in files. Additionally, the keystore currently utilizes files so people are likely already used to backing up keys this way.

[Stebalien]

Hm. Is there any reason not to allow this?

[aschmahmann]

I guess not, but we have to the keys live in different places and it's a little messier. Let's add it in a followup PR

[aschmahmann]

@rendaw this looks pretty good so I'm going to merge it. Thanks for the hard work. We're trying to move along a release candidate for 0.7.0 soon and I wanted to get this in.

If you have any questions/thoughts about design decisions I made in the last week feel free to comment here or in a new issue and we can always file more PRs 😄

[rendaw]

Awesome, thanks for helping me out here! The sounds good. The actual form of this functionality isn't so important to me anyway.