new calculation method: arbitrary EIP-712 messags.

[PatrickAlphaC]

Abstract

Many users often have to sign typed EIP-712 data, but they don't understand what they are signing, this goes for Safe Wallets as well. It would. be great to have a new input method called EIP-712 or Typed Data where they can drop in their JSON of their EIP-712 data and get back the message hashes they are actually signing.

This makes verifying on their hardware wallets MUCH easier, as they can just compare the hashes as opposed to having to scroll through 100 pages on something like a Trezor or Ledger device.

Example

Example JSON:

{
  "domain": {
    "name": "SecurityCouncil",
    "version": "1",
    "chainId": 1,
    "verifyingContract": "0x66E4431266DC7E04E7d8b7FE9d2181253df7F410"
  },
  "primaryType": "ApproveUpgradeSecurityCouncil",
  "types": {
    "EIP712Domain": [
      {
        "name": "name",
        "type": "string"
      },
      {
        "name": "version",
        "type": "string"
      },
      {
        "name": "chainId",
        "type": "uint256"
      },
      {
        "name": "verifyingContract",
        "type": "address"
      }
    ],
    "ApproveUpgradeSecurityCouncil": [
      {
        "name": "id",
        "type": "bytes32"
      }
    ]
  },
  "message": {
    "id": "0x2d3883b5d936c6a3c8b4170c4735bbf437de601b3f5afaceeee27b6b52907574"
  }
}

Should result in:

+--------------+--------------------------------------------------------------------+
| EIP 712 Hash | 0x1be8e5ff60e3a11c229dd65f64fcead922ed2e56991362d76f5df5a8e7d4c1c0 |
+--------------+--------------------------------------------------------------------+
| Domain Hash  | 0x4b060214423f60c76da4f8d80253b7c6b565786aaae7afef3be4ae257c66761b |
+--------------+--------------------------------------------------------------------+
| Message Hash | 0x90f31eb2908ee603c92ad37c726548296cf52ed6c4edd39876c3b5dd09447ae5 |
+--------------+--------------------------------------------------------------------+

You can get this from the safe-hash tool by running:

safe-hash typed --file file.json

[josepchetrit12]

@PatrickAlphaC thanks for the issue. We will check it out.

cc @ferrabled