Bool encoding ("0" & "false") discrepancy on TypedDataUtils.eip712Hash

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Assessment

Difficulty
3/5
Estimated time
1-2 days
Newbie friendliness
48/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Stale
Tech stack
typescript
Domain
blockchain, cryptography

Research direction

Start at the TypedDataUtils.eip712Hash entry point and reproduce the two examples using data_false as numeric 0 and string "false". Compare the resulting bool encoding with the EIP-712 rule that bool values match uint256 0 or 1; the issue is done when equivalent false inputs produce the same hash.

Written by the indexing model from the issue text.

Description

I was testing bool property encoding using TypedDataUtils.eip712Hash but I noticed different output when I change "false" to 0.

Proof

 const hash = TypedDataUtils.eip712Hash(
    {
      types: {
        EIP712Domain: [
          {
            name: 'name',
            type: 'string',
          },
          {
            name: 'version',
            type: 'string',
          },
          {
            name: 'chainId',
            type: 'uint256',
          },
          {
            name: 'verifyingContract',
            type: 'address',
          },
        ],
        Message: [
          { name: 'data_true', type: 'bool' },
          { name: 'data_false', type: 'bool' },
        ],
      },
      primaryType: 'Message',
      domain: {
        name: 'com.test.test',
        version: '1',
        chainId: 1,
        verifyingContract: '0xc000000000000000000000000000000000000000',
      },
      message: {
        data_true: 'true',
        data_false: 0,
      },
      
    },
    SignTypedDataVersion.V4,
  ).toString('hex');

  console.log(`result bool ->  ${hash}`)

This gives "0737ed294ff3a12f840067c728e500008f23a7b79f4a62c09b5d1bbca85ddb2e"

  1. Change data_false: 0 to data_false: 'false' then the output is changed to "1a3a9fdfbecde2bb500792a5cdfc2d0deca9401edafa4186d71f5842ecf12d0b"

Seems "false" is wrongly mapped, when I give "false" and "1" it gives the same output

PS: According to Eip-712 spec bool values should be encoded same as uint256 0 or 1. I tested uint256 0 and 1 values and I confirm it gives correct output

Dominant language
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