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Coze Javascript - cryptographic JSON messaging specification

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⚠️ COZE IS IN ALPHA. USE AT YOUR OWN RISK ⚠️

Coze

For Coze, please see the README in the Main Coze Project.

For your project use coze.min.js.

Developing Coze JS

How to Build

Install esbuild

If using Go, esbuild can be installed with the following.

go install github.com/evanw/esbuild/cmd/esbuild@v0.15.8

Alternatively, see esbuild's installation instructions. Also, Coze JS npm.

Create the Coze distribution file.

(See join.js for more instructions.)

esbuild join.js --bundle --format=esm --minify --outfile=coze.min.js
cp coze.min.js verifier/coze.min.js

Simple Coze Verifier

The simple verifier is self-contained in /verifier.

To run the simple verifier locally, especially useful for local development, use the Go server.

cd verifier
go run server.go

And then go to https://localhost:8082/coze.html in your browser.

Testing

Coze uses BrowserTestJS for running unit tests in the browser. The test can run as a Github page.

For local development, use the Go server.

cd verifier/browsertest
go run server.go

Then go to https://localhost:8082.

Coze Javascript Gotchas

  • ⚠️ Javascript is not constant time. Until there's something available with constant time guarantees, like constant time WASM, this library will be vulnerable to timing attacks as this problem is inherent to Javascript.

  • Duplicate detection is outside the scope of Coze JS because Coze JS uses Javascript objects which always have unique fields. Also, no JSON parsing is done inside of Coze JS, which uses last-value-wins. - Objects in ES6 defined with duplicate fields uses last-value-wins.

    • See notes on test_Duplicate.
  • ES224 is not supported. Even though FIPS 186 defines curves P-224, the W3C recommendation omits it and thus is not implemented in Javascript. The Javascript version of Coze will probably only support ES256, ES384, and ES512.

  • The W3C Web Cryptography API recommendation also omits Ed25519, so an external package that implements the Ed25519 primitive is used. The upcoming update FIPS 186-5 section 7.8 specifies Ed25519 support. Hopefully this will motivate Javascript to include Ed25519. Also, Paul has implemented Ed25519ph.

  • TODO use Paul's curves library. Currently ESM builds are "broken", and we'll wait for it to be polished. (The imports are using Typescript @ imports and not resolving to ESM files.)

    Also, we'll preserve the current style somewhere so that we have a SubtleCrypto backend that can be used.

  • Javascript's SubtleCrypto.sign(algorithm, key, data) always hashes a message before signing while Go's ECDSA expects a digest to sign. This means that in Javascript messages must be passed for signing, while in Go only a digest is needed.


Attribution, Trademark Notice, and License

Coze and CozeJS are released under The 3-Clause BSD License.

"Cyphr.me" is a trademark of Cypherpunk, LLC. The Cyphr.me logo is all rights reserved Cypherpunk, LLC and may not be used without permission.