https://github.com/summa-tx/satmask

🛰️🎭
https://github.com/summa-tx/satmask

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• Host: GitHub
• URL: https://github.com/summa-tx/satmask
• Owner: summa-tx
• License: other
• Created: 2020-03-15T19:41:33.000Z (almost 5 years ago)
• Default Branch: master
• Last Pushed: 2021-03-12T14:31:23.000Z (almost 4 years ago)
• Last Synced: 2023-03-02T19:15:43.156Z (almost 2 years ago)
• Language: JavaScript
• Size: 958 KB
• Stars: 10
• Watchers: 2
• Forks: 0
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • License: LICENSE-APACHE2.md

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README

        
# SatMask

Proof of Concept code for signing Bitcoin transactions via MetaMask.

DO NOT USE THIS CODE IN PRODUCTION.

### How it works

MetaMask's `eth_sign` api allows the user to sign arbitrary digests. Unlike

geth, it does not modify or hash the argument. This means we can calculate the

sighash of a Bitcoin transaction and pass it to `eth_sign`. After that, we

need to translate the signature from Ethereum's hex-encoded RSV standard to

Bitcoin's DER-Encoded RS format, and add the signature to the transaction.

Calculating the sighash requires knowledge of the public key that will sign,

so an extra `personal_sign` call is made. This generates a signature from which

we can recover the users' pubkey to use in the sighash algorithm.

The current version signs only transactions with 1 witness pubkeyhash input and

one witness pubkeyhash output. The resulting transaction is logged to console.

### A brief tour of the codebase

- `src/tx.js` handles transaction datastructure manipulation. This includes

construction, sighash serialization, and adding the signature to the

transaction (inside a witness).

- `src/sigs.js` handles interfacing with MetaMask, retrieving the signature,

and translating from RSV to DER.

- `src/App.js` is a simple react app that provides a convenient interface for

specifying a transaction. All credit to [@tynes](https://github.com/tynes/) for

this part :)

### How to run it

Don't. Like really don't. Read the code, but don't run it.