SwapChan
Never holds your keys Ā· your wallet signs
Related:All recipesFind forgotten money across chains (blocktools + SwapChan)Use a chain without its wallet app (example: older coins like Feathercoin, Peercoin, Qtum)Simulate and verify before you sign
blocktools CLI

EVM: check an EIP-712 signature and digest

Task: see what a typed-data signature commits to (domain separator, message hash, digest) and who signed it, offline. Part of the EVM contract recipes.ā€¦

āš ļø DANGEROUS: use at your own risk. Code that handles keys and signs transactions should always be read and audited by you before you trust it with real funds. Used incorrectly, it can destroy your money.

Task: see what a typed-data signature commits to (domain separator, message hash, digest) and who signed it, offline. Part of the EVM contract recipes. Real dApp requests: evm-permit2-signing-request.md, evm-check-approval.md.

fixtures/evm/eip712-mail-signed.json is the Mail example from the EIP-712 specification with its published signature:

typed-data-verify recipes/fixtures/evm/eip712-mail-signed.json | jq -c '{primary_type, chain_id, recovered, status}'

A different expected signer is a mismatch (exit 1):

typed-data-verify --signer 0xbBbBBBBbbBBBbbbBbbBbbbbBBbBbbbbBbBbbBBbB recipes/fixtures/evm/eip712-mail-signed.json

An eth_signTypedData_v4 request ({"params": [address, typedData]}) can be piped in as-is with --sig; its address becomes the expected signer. Live (UNTESTED here): capture the request a dApp sends and the signature the wallet returns, then typed-data-verify --sig 0xā€¦ request.json.