OpenChainGraph Suite · ART-612 · ERC-2612 / EIP-712 Crypto Primitive

ERC-2612 Permit Binding Verifier

Recomputes the EIP-712 typed-data digest for an ERC-2612 Permit struct (the gasless-approval rail used by USDC/DAI-style tokens): digest = keccak256(0x19 || 0x01 || domainSeparator || structHash), recovers the ECDSA signer from a caller-supplied signature, and reports whether the recovered signer binds to the caller-claimed owner or names the diverging field. All four EIP-712 domain fields (name, version, chainId, verifyingContract) are mandatory inputs and are never defaulted or guessed (a guessed verifyingContract would defeat the entire point of domain separation). This node makes no claim about on-chain nonce freshness, current allowance state, or whether deadline has passed relative to now.

EIP-712 / ERC-2612keccak256 + secp256k1 (vendored, no hand-rolled crypto)Binds / does not bind, never "valid/approved/authorized"

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EIP-712 Domain (all four fields mandatory, never defaulted)

name

version

chainId

verifyingContract

A guessed or omitted domain field defeats domain separation: this node refuses to compute a digest without all four.

Permit Struct

owner (claimed signer)

spender

value (uint256)

nonce (uint256 counter)

deadline (uint256 unix time)

Signature (r, s, and yParity/v)

r (32 bytes)

s (32 bytes)

yParity (0 or 1); leave blank to use v instead

Accepts a raw recovery bit (yParity 0/1), legacy Ethereum v (27/28), or EIP-155 v (chainId*2+35/36); supply exactly one.

Domain Separator

Struct Hash

Digest (the bytes a wallet signs)

Recovered Signer

recovered_signer_matches_owner

diverging_field

Typehash Constants

EIP712Domain typehash

Permit typehash

Execution Hash (SHA-256)