Verify an EIP-712 signature

This walks through the claim case of vectors/signing-v3.json. The vectors are computed at the local fork addresses on chain id 84532. The same steps apply to every type in Signing. Requires cast and jq, run from the repository root.

1. Rebuild the domain separatorCopy Anchor Link

Claim is verified by JobRegistry (VORQ Jobs, version 2):

DOMAIN_TYPEHASH=$(cast keccak "EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)")
SEP=$(cast keccak $(cast abi-encode "f(bytes32,bytes32,bytes32,uint256,address)" \
  $DOMAIN_TYPEHASH $(cast keccak "VORQ Jobs") $(cast keccak "2") 84532 \
  0xe7f1725E7734CE288F8367e1Bb143E90bb3F0512))
echo $SEP   # 0x3f0c928d3c1e283abf4a1c86884de6c9c2d0f759a41f4b1e5482f2973768ff4d

Against a deployed contract, compare with its DOMAIN_SEPARATOR(). A mismatch means a wrong address or chain:

cast call <JobRegistry address> "DOMAIN_SEPARATOR()(bytes32)" --rpc-url <rpc>

2. Hash the structCopy Anchor Link

CLAIM_TYPEHASH=$(cast keccak "Claim(bytes32 jobId,uint64 issuedAt)")
STRUCT=$(cast keccak $(cast abi-encode "f(bytes32,bytes32,uint64)" \
  $CLAIM_TYPEHASH 0x74df3a3c4f813c80a4d5e27bd099a78751a21c05735003c6b86430aa2bbd8b40 1800000000))

Each member is ABI-encoded as a 32-byte word. A bytes member (SetIdentity.evidence) is encoded as its keccak256; an array of structs (AskSnapshot.quotes) as the keccak256 of the concatenated element hashes.

3. Build the digestCopy Anchor Link

DIGEST=$(cast keccak 0x1901${SEP#0x}${STRUCT#0x})
echo $DIGEST   # 0xde48afcd388bd3582c6c178b85d36ef841e258b2bc2b64cbe18bf0a0514118fe

The value must equal the case's digest.

4. Check the signatureCopy Anchor Link

Signatures are 65 bytes, r || s || v, with v 27 or 28:

SIG=$(jq -r '.cases[] | select(.name=="claim") | .signature' vectors/signing-v3.json)
cast wallet verify --no-hash --address 0x90F79bf6EB2c4f870365E785982E1f101E93b906 $DIGEST $SIG

Or verify straight from the case's typed data, which checks your wallet library's EIP-712 encoding end to end:

jq '.cases[] | select(.name=="claim") | .typed_data' vectors/signing-v3.json > claim.json
cast wallet verify --data --from-file --address 0x90F79bf6EB2c4f870365E785982E1f101E93b906 claim.json $SIG

The signer is the local fork's provider operator (Anvil account #3). Signing claim.json with its public dev key reproduces the case's signature exactly:

cast wallet sign --data --from-file \
  --private-key 0x7c852118294e51e653712a81e05800f419141751be58f605c371e15141b007a6 claim.json

If a digest does not matchCopy Anchor Link

• Compare the type string byte for byte with Signing: no spaces after commas, members in declaration order.
• For AskSnapshot, the encoded type is the primary type followed by Ask(...); quote order changes the digest.
• Order has nine signed members. The Solidity struct's tenth member, taskCid, is not signed.
• The payment authorization is signed on the USDC domain, not a VORQ domain.