Initial commit

solidity/Makefile

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+all:
+	solc TokenEndorser.sol --abi | awk 'NR>3' > TokenEndorser.json
+	solc TokenEndorser.sol --bin | awk 'NR>3' > TokenEndorser.bin
+	truncate -s -1 TokenEndorser.bin
+
+test: all
+	python test.py
+	
+.PHONY: test

solidity/TokenEndorser.json

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+[{"inputs":[],"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_token","type":"address"},{"indexed":true,"internalType":"address","name":"_adder","type":"address"},{"indexed":true,"internalType":"uint256","name":"_index","type":"uint256"},{"indexed":false,"internalType":"bytes32","name":"_data","type":"bytes32"}],"name":"EndorsementAdded","type":"event"},{"inputs":[{"internalType":"address","name":"_token","type":"address"},{"internalType":"bytes32","name":"_data","type":"bytes32"}],"name":"add","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"bytes32","name":"","type":"bytes32"}],"name":"endorsement","outputs":[{"internalType":"bytes32","name":"","type":"bytes32"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"","type":"address"},{"internalType":"uint256","name":"","type":"uint256"}],"name":"endorsers","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"","type":"address"}],"name":"tokenIndex","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"uint256","name":"","type":"uint256"}],"name":"tokens","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"}]

solidity/TokenEndorser.sol

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+pragma solidity >=0.6.12;
+
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+contract TokenEndorsement {
+
+	uint256 count;
+	mapping ( bytes32 => bytes32 ) public endorsement;
+	mapping ( address => uint256 ) public tokenIndex;
+	mapping ( address => uint256[] ) public endorsers;
+	address[] public tokens;
+
+	event EndorsementAdded(address indexed _token, address indexed _adder, uint256 indexed _index, bytes32 _data);
+
+	constructor() {
+		count = 1;
+		tokens.push(address(0x0));
+	}
+
+	function register(address _token) private returns (bool) {
+		if (tokenIndex[_token] > 0) {
+			return false;
+		}
+		tokens.push(_token);
+		tokenIndex[_token] = count;
+		count++;
+		return true;
+	}
+
+	function add(address _token, bytes32 _data) public returns (bool) {
+		register(_token);
+		bytes32 k;
+		bytes memory signMaterial = new bytes(40);
+		bytes memory addrBytes = abi.encodePacked(_token);
+		for (uint256 i = 0; i < 20; i++) {
+			signMaterial[i] = addrBytes[i];
+		}
+		addrBytes = abi.encodePacked(msg.sender);
+		for (uint256 i = 0; i < 20; i++) {
+			signMaterial[i+20] = addrBytes[i];
+		}
+		k = sha256(signMaterial);
+		require(endorsement[k] == bytes32(0x00));
+		endorsement[k] = _data;
+		endorsers[msg.sender].push(tokenIndex[_token]);
+		emit EndorsementAdded(_token, msg.sender, count, _data);
+		return true;
+	}
+}

solidity/test.py

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+import logging
+import os
+import json
+import hashlib
+
+import web3
+import eth_tester
+
+logging.basicConfig(level=logging.DEBUG)
+logg = logging.getLogger()
+
+
+eth_params = eth_tester.backends.pyevm.main.get_default_genesis_params({
+    'gas_limit': 9000000,
+    })
+backend = eth_tester.PyEVMBackend(eth_params)
+instance = eth_tester.EthereumTester(backend)
+provider = web3.Web3.EthereumTesterProvider(instance)
+w3 = web3.Web3(provider)
+
+
+f = open('TokenEndorser.bin', 'r')
+bytecode = f.read()
+f.close()
+
+f = open('TokenEndorser.json', 'r')
+abi = json.load(f)
+f.close()
+
+token_address = web3.Web3.toChecksumAddress('0x' + os.urandom(20).hex())
+
+c = w3.eth.contract(abi=abi, bytecode=bytecode)
+tx_hash = c.constructor().transact({'from': w3.eth.accounts[0]})
+r = w3.eth.getTransactionReceipt(tx_hash)
+logg.debug('contract {} initial token {}'.format(r.contractAddress, token_address))
+
+c = w3.eth.contract(abi=abi, address=r.contractAddress)
+d = '0x' + os.urandom(32).hex()
+
+# Initial token will fail in any case
+c.functions.add(token_address, d).transact({'from':w3.eth.accounts[0]})
+
+fail = False
+try:
+    c.functions.add(token_address, d).transact({'from':w3.eth.accounts[0]})
+except:
+    fail = True
+    pass
+
+if not fail:
+    raise RuntimeError('expected fail on register same token to same address')
+
+
+c.functions.add(token_address, d).transact({'from':w3.eth.accounts[1]})
+
+
+h = hashlib.new('sha256')
+h.update(bytes.fromhex(token_address[2:]))
+h.update(bytes.fromhex(w3.eth.accounts[0][2:]))
+z = h.digest()
+
+assert d[2:] == c.functions.endorsement(z.hex()).call().hex()
+
+
+another_token_address = web3.Web3.toChecksumAddress('0x' + os.urandom(20).hex())
+c.functions.add(another_token_address, d).transact({'from':w3.eth.accounts[0]})
+
+assert c.functions.endorsers(w3.eth.accounts[0], 0).call() == 1
+assert c.functions.endorsers(w3.eth.accounts[1], 0).call() == 1
+assert c.functions.endorsers(w3.eth.accounts[0], 1).call() == 2
+
+assert c.functions.tokens(1).call() == token_address
+assert c.functions.tokens(2).call() == another_token_address
+
+assert c.functions.tokenIndex(token_address).call() == 1
+assert c.functions.tokenIndex(another_token_address).call() == 2
+
+