Module: Siwe::SmartWallet

Defined in:
lib/siwe/smart_wallet.rb

Overview

Smart-wallet signature verification via the EIP-6492 off-chain universal validator. A single eth_call (deploy-and-call) covers both deployed ERC-1271 wallets (e.g. Safe) and counterfactual EIP-6492-wrapped signatures (e.g. Coinbase Smart Wallet).

Class Method Summary collapse

Class Method Details

.bin_to_hex(bin) ⇒ Object 



59
60
61
 
# File 'lib/siwe/smart_wallet.rb', line 59

def bin_to_hex(bin)
  bin.unpack1("H*")
end

.eip191_hash(message) ⇒ Object

Hash a message per EIP-191 (‘personal_sign`). Returns binary keccak256.



40
41
42
43
 
# File 'lib/siwe/smart_wallet.rb', line 40

def eip191_hash(message)
  prefixed = Eth::Signature.prefix_message(message)
  Eth::Util.keccak256(prefixed)
end

.result_indicates_valid?(hex) ⇒ Boolean

Validator returns 0x01 (possibly zero-padded to 32 bytes) for valid, 0x00 for invalid. The default RPC client strips the 0x prefix; for callers that don’t, normalize here.

Returns:

  • (Boolean) 


48
49
50
51
52
53
 
# File 'lib/siwe/smart_wallet.rb', line 48

def result_indicates_valid?(hex)
  return false if hex.nil?

  hex = strip_hex_prefix(hex.to_s)
  hex.gsub(/\A0+/, "") == "1"
end

.strip_hex_prefix(hex) ⇒ Object 



55
56
57
 
# File 'lib/siwe/smart_wallet.rb', line 55

def strip_hex_prefix(hex)
  hex.start_with?("0x") ? hex[2..] : hex
end

.verify(rpc:, address:, message:, signature:) ⇒ Object

Verify a smart-wallet signature. rpc — anything responding to ‘eth_call(to:, data:, block:)` address — claimed signer (smart contract or factory-deployed address) message — EIP-4361 message string (will be EIP-191 hashed internally) signature — hex-encoded signature, may or may not include 0x prefix,

may include the EIP-6492 magic-suffix wrapper

Returns true (valid) or false (validator returned non-1). Re-raises Siwe::Error from the rpc client on transport errors.



25
26
27
28
29
30
31
32
33
34
35
36
37
 
# File 'lib/siwe/smart_wallet.rb', line 25

def verify(rpc:, address:, message:, signature:) # rubocop:disable Naming/PredicateMethod
  hash_hex = bin_to_hex(eip191_hash(message))
  sig_hex = strip_hex_prefix(signature)

  args = Eth::Abi.encode(
    %w[address bytes32 bytes],
    [address, Eth::Util.hex_to_bin(hash_hex), Eth::Util.hex_to_bin(sig_hex)]
  )
  data = "0x#{Eip6492::VALIDATOR_BYTECODE}#{Eth::Util.bin_to_hex(args)}"

  result = rpc.eth_call(to: nil, data: data)
  result_indicates_valid?(result)
end