New default KDF

[savely-krasovsky]

HKDF-HMAC-SHA256 instead of just SHA256

[codecov]

Codecov Report

Merging #83 into master will not change coverage.
The diff coverage is 100%.

@@          Coverage Diff          @@
##           master    #83   +/-   ##
=====================================
  Coverage     100%   100%           
=====================================
  Files           7      7           
  Lines         162    171    +9     
  Branches        5      5           
=====================================
+ Hits          162    171    +9

Impacted Files	Coverage Δ
src/keys/PrivateKey.ts	100% <100%> (ø)	⬆️
src/index.ts	100% <100%> (ø)	⬆️
src/keys/PublicKey.ts	100% <100%> (ø)	⬆️
src/tests/crypt.test.ts	100% <100%> (ø)	⬆️

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[kigawas]

Can you add some test cases?

[savely-krasovsky]

@kigawas it tests against your Python backend, I cannot fix it.

[kigawas]

ecies/py#87

[savely-krasovsky]

@kigawas did you test it with JS one?

[kigawas]

I'll test it later today

[kigawas]

    def test_hdkf(self):
        k1 = PrivateKey(secret=bytes([2]))
        self.assertEqual(k1.to_int(), 2)

        k2 = PrivateKey(secret=bytes([3]))
        self.assertEqual(k2.to_int(), 3)

        self.assertEqual(
            encapsulate(k1, k2.public_key), decapsulate(k1.public_key, k2)
        )
        self.assertEqual(
            encapsulate(k1, k2.public_key).hex(),
            '6f982d63e8590c9d9b5b4c1959ff80315d772edd8f60287c9361d548d5200f82'
        )

[savely-krasovsky]

@kigawas if you were surprised with encapsulate/decapsulate syntax, I took it from google's tink, because we need same public key. KEM is just key encapsulation mechanism. ECIES is basically KEM+DEM (data encapsulation mechanism).

[savely-krasovsky]

@kigawas let me know when you will have deployed new Python backend at Heroku. I want to test Go version against it.

[kigawas]

@L11r
Already deployed

[savely-krasovsky]

@kigawas if so, JS tests still fail 🤔
AES-GCM cannot decrypt data.
(node:109) UnhandledPromiseRejectionWarning: Error: Unsupported state or unable to authenticate data

[kigawas]

I'll fix js version, wait a sec

[kigawas]

Looks ok for now.
Basically the reason is ecdhUnsafe was returning compressed public key format

[savely-krasovsky]

@kigawas yeah, already got it. Will fix Go version soon.

[kigawas]

        derived = HKDF(b'secret', 32, b'', SHA256).hex()
        self.assertEqual(
            derived,
            "2f34e5ff91ec85d53ca9b543683174d0cf550b60d5f52b24c97b386cfcf6cbbf"
        )

You can use this to check hkdf

[savely-krasovsky]

@kigawas yeah, already done.

ecies/go#3