support signTypedMessage

[ansoncsh]

Add the method signTypedMessage to support EIP-712

[odanado]

@ansoncsh Sorry for the late reply.

I am currently implementing a test for signTypedMessage

It would be easier to implement the tests if you have sample code using signTypedMessage. Do you have sample code?

[ansoncsh]

@odanado

Sorry for my late response. Please find the sample code below:

const provider = new KmsProvider(rpcUrl, { region, keyIds: [keyId] });
const accounts = await provider.getAccounts();
const digest = "0xbe609aee343fb3c4b28e1df9e632fca64fcfaede20f02e86244efddf30957bd2"
const signature = await provider.signTypedMessage({
    from: accounts[0],
    data: digest
})

The parameter digest refers to this EIP-712 example

[odanado]

@ansoncsh According to EIP-712, the second argument of eth_signTypedData should be the data before hashing https://eips.ethereum.org/EIPS/eip-712#specification-of-the-eth_signtypeddata-json-rpc

Have you tried implementing passing hashed data to data in other wallets such as MetaMask?

[ansoncsh]

@ansoncsh According to EIP-712, the second argument of eth_signTypedData should be the data before hashing https://eips.ethereum.org/EIPS/eip-712#specification-of-the-eth_signtypeddata-json-rpc

Have you tried implementing passing hashed data to data in other wallets such as MetaMask?

@odanado I didn't try it

From my case,

• use KMS wallet to sign a meta transaction for Contract A
• pass signature to Contract B
• execute meta transaction from Contract B

Just notice that it works on my case but not work on MetaMask.

[odanado]

OK.

I tried signTypedMessage with ethers. https://github.com/odan-sandbox/sign-typed-data-sandbox/blob/34add5f0f8411daf673ea360be1ca3ffcfd2f373/hooks/useSignTypedData.ts#L42-L47

This resulted in the following error.

Error: Cannot convert string to buffer. toBuffer only supports 0x-prefixed hex strings and this string was given: {"types":{"Person":[{"name":"name","type":"string"},{"name":"wallet","type":"address"}],"Mail":[{"name":"from","type":"Person"},{"name":"to","type":"Person"},{"name":"contents","type":"string"}],"EIP712Domain":[{"name":"name","type":"string"},{"name":"version","type":"string"},{"name":"chainId","type":"uint256"},{"name":"verifyingContract","type":"address"}]},"domain":{"name":"Ether Mail","version":"1","chainId":"1","verifyingContract":"0xcccccccccccccccccccccccccccccccccccccccc"},"primaryType":"Mail","message":{"from":{"name":"Cow","wallet":"0xcd2a3d9f938e13cd947ec05abc7fe734df8dd826"},"to":{"name":"Bob","wallet":"0xbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb"},"contents":"Hello, Bob!"}}

I am implementing a fix to prevent this error from occurring.

[coveralls]

Pull Request Test Coverage Report for Build 3156097120

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 88.0%

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Totals
Change from base Build 3046947450:	0.0%
Covered Lines:	118
Relevant Lines:	131

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💛 - Coveralls

[odanado]

@ansoncsh Changed eth_signTypedData to pass raw data as the second argument Can you confirm that this is available for your use case?

[ansoncsh]

@ansoncsh Changed eth_signTypedData to pass raw data as the second argument Can you confirm that this is available for your use case?

Yes, it works for my case too. Thanks!

[odanado]

@ansoncsh LGTM Thank you!

[odanado]

This change was released at [email protected].