# Claim Digest (EIP-712)

Calculate the digest from the validated [common claim](/implementers/common-claim)
using [EIP-712](https://eips.ethereum.org/EIPS/eip-712). JSON and CBOR envelope
bytes are not the signing input.

## Domain

For `ensrv1` on Ethereum mainnet, use exactly:

```json
{
  "name": "ENS Record Verification",
  "version": "1",
  "chainId": 1
}
```

The domain type is `EIP712Domain(string name,string version,uint256 chainId)`.
Omit `verifyingContract` and `salt`; do not insert zero values for absent fields.
`chainId` identifies the ENS deployment. It remains `1` when a method checks an
account on another chain; that target chain is bound through the method's target.

## Claim Type

Use this exact string, with no line breaks or extra spaces:

```text
ENSRecordVerification(string name,bytes32 node,string recordType,string recordKey,bytes32 valueHash,uint32 authorityVersion,address authority,string method,string target,uint64 issuedAt,uint64 validUntil)
```

Its Keccak-256 hash is `claimTypeHash`. The primary type supplied to a wallet is
`ENSRecordVerification`.

## Calculation

For each string, hash its exact UTF-8 bytes. Keep `bytes32` values unchanged.
Encode unsigned integers and the address as 32-byte, left-zero-padded values.
Then concatenate the words in the declared order:

```pseudocode
domainSeparator = keccak256(abi.encode(
    keccak256(UTF8(domainType)),
    keccak256(UTF8("ENS Record Verification")),
    keccak256(UTF8("1")),
    uint256(1)
))

claimStructHash = keccak256(abi.encode(
    claimTypeHash,
    keccak256(UTF8(name)), node,
    keccak256(UTF8(recordType)), keccak256(UTF8(recordKey)),
    valueHash, uint32(authorityVersion), address(authority),
    keccak256(UTF8(method)), keccak256(UTF8(target)),
    uint64(issuedAt), uint64(validUntil)
))

commonClaimDigest = keccak256(
    hexBytes("1901") || domainSeparator || claimStructHash
)
```

`abi.encode` uses standard 32-byte ABI words, not packed integers. The final
hash has a 66-byte input: two prefix bytes and two 32-byte hashes.

## Wallet Input

Supply `domain`, `types`, `primaryType`, and `message` to a typed-data signing
API. `message` contains the common claim. It does not contain envelope `v`,
`authoritySignature`, or `proof`.

Parse wire integers into exact integer values supported by the signing library.
Never convert a `uint64` through a JavaScript `number` that loses precision.
Do not add a personal-sign prefix or sign the hexadecimal digest as text.

## Test Vector

The shared <a href="/vectors/common-claim-v1.json" download>claim and proof-key vector</a> contains
one fixed claim, typed-data input, encoded hash inputs, and expected intermediate
hashes. It is a calculation fixture, not evidence that the example name or
account has live ownership. See the selected values below.

```text
claimTypeHash = 0xa40ff36f3189ec95e12e6d89e8cbfcdc35f598bebca66561e8c1221b8cd78c2d
domainSeparator = 0x13e18e785741386cdda7b13ad2e40f5c26c940f9942e80ff9baeb53f50ee3aaa
claimStructHash = 0x3598240a66023467261d422f7973ef617224a9cfca884a4ba948c75102a4beb3
commonClaimDigest = 0xdd4f601548768d2213b42b2be359d92e0f47adf25f6ae536cd206428ea65ef8d
```

Changing a claim field must change the digest. Reordering JSON members or
encoding the same logical claim as CBOR must not. These examples do not replace
the full conformance corpus, including signature and invalid-input cases.