Compiled contracts

python/CHANGELOG

@@ -1,9 +1,11 @@
-* 0.0.10-pending
+* 0.1.10
+	- Apply transfer ownership protection in GiftableToken contract
+* 0.1.9
+	- Add statictoken contract
+* 0.0.10
 	- Upgrade chainlib dependency, providing customizable jsonrpc id
 	- Move to chainlib-eth
-* 0.0.9-unreleased
+* 0.0.7
-* 0.0.8-unreleased
-* 0.0.7-unreleased
 	- Implement keystore signing.
 	- Change makefile to compile contract for Byzantium.
 	- Change mint method name to mintTo

python/eth_erc20/runnable/approve.py

@@ -0,0 +1,99 @@
+#!python3
+
+"""Token transfer script
+
+.. moduleauthor:: Louis Holbrook <dev@holbrook.no>
+.. pgp:: 0826EDA1702D1E87C6E2875121D2E7BB88C2A746 
+
+"""
+
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+# standard imports
+import os
+import io
+import json
+import argparse
+import logging
+
+# external imports
+from hexathon import (
+        add_0x,
+        strip_0x,
+        )
+from chainlib.eth.connection import EthHTTPConnection
+from chainlib.chain import ChainSpec
+from chainlib.eth.runnable.util import decode_for_puny_humans
+from chainlib.eth.address import to_checksum_address
+import chainlib.eth.cli
+
+# local imports
+from eth_erc20 import ERC20
+
+logging.basicConfig(level=logging.WARNING)
+logg = logging.getLogger()
+
+arg_flags = chainlib.eth.cli.argflag_std_write | chainlib.eth.cli.Flag.EXEC | chainlib.eth.cli.Flag.WALLET 
+argparser = chainlib.eth.cli.ArgumentParser(arg_flags)
+argparser.add_positional('amount', type=int, help='Token amount to send')
+args = argparser.parse_args()
+extra_args = {
+    'amount': None,
+        }
+config = chainlib.eth.cli.Config.from_args(args, arg_flags, extra_args=extra_args, default_fee_limit=100000)
+
+block_all = args.ww
+block_last = args.w or block_all
+
+wallet = chainlib.eth.cli.Wallet()
+wallet.from_config(config)
+
+rpc = chainlib.eth.cli.Rpc(wallet=wallet)
+conn = rpc.connect_by_config(config)
+
+chain_spec = ChainSpec.from_chain_str(config.get('CHAIN_SPEC'))
+
+value = config.get('_AMOUNT')
+
+send = config.true('_RPC_SEND')
+
+def main():
+
+    signer = rpc.get_signer()
+    signer_address = rpc.get_sender_address()
+
+    gas_oracle = rpc.get_gas_oracle()
+    nonce_oracle = rpc.get_nonce_oracle()
+
+    g = ERC20(chain_spec, signer=signer, gas_oracle=gas_oracle, nonce_oracle=nonce_oracle)
+
+    recipient = to_checksum_address(config.get('_RECIPIENT'))
+    if not config.true('_UNSAFE') and recipient != add_0x(config.get('_RECIPIENT')):
+        raise ValueError('invalid checksum address for recipient')
+
+    token_address = to_checksum_address(config.get('_EXEC_ADDRESS'))
+    if not config.true('_UNSAFE') and token_address != add_0x(config.get('_EXEC_ADDRESS')):
+        raise ValueError('invalid checksum address for contract')
+
+    (tx_hash_hex, o) = g.approve(token_address, signer_address, recipient, value, id_generator=rpc.id_generator)
+
+    if send:
+        conn.do(o)
+        if block_last:
+            r = conn.wait(tx_hash_hex)
+            if logg.isEnabledFor(logging.DEBUG):
+                sender_balance = balance(g, token_address, signer_address, id_generator=rpc.id_generator)
+                recipient_balance = balance(g, token_address, recipient, id_generator=rpc.id_generator)
+                logg.debug('sender {} balance after: {}'.format(signer_address, sender_balance))
+                logg.debug('recipient {} balance after: {}'.format(recipient, recipient_balance))
+            if r['status'] == 0:
+                logg.critical('VM revert. Wish I could tell you more')
+                sys.exit(1)
+        print(tx_hash_hex)
+
+    else:
+        print(o['params'][0])
+
+
+if __name__ == '__main__':
+    main()

python/eth_erc20/runnable/transfer.py

@@ -24,7 +24,10 @@ from hexathon import (
 from chainlib.eth.connection import EthHTTPConnection
 from chainlib.chain import ChainSpec
 from chainlib.eth.runnable.util import decode_for_puny_humans
-from chainlib.eth.address import to_checksum_address
+from chainlib.eth.address import (
+        to_checksum_address,
+        is_same_address,
+        )
 import chainlib.eth.cli
 
 # local imports
@@ -35,10 +38,12 @@ logg = logging.getLogger()
 
 arg_flags = chainlib.eth.cli.argflag_std_write | chainlib.eth.cli.Flag.EXEC | chainlib.eth.cli.Flag.WALLET 
 argparser = chainlib.eth.cli.ArgumentParser(arg_flags)
+argparser.add_argument('--from', type=str, help='Address to send on behalf of') 
 argparser.add_positional('amount', type=int, help='Token amount to send')
 args = argparser.parse_args()
 extra_args = {
     'amount': None,
+    'from': None,
         }
 config = chainlib.eth.cli.Config.from_args(args, arg_flags, extra_args=extra_args, default_fee_limit=100000)
 
@@ -82,22 +87,37 @@ def main():
     if not config.true('_UNSAFE') and token_address != add_0x(config.get('_EXEC_ADDRESS')):
         raise ValueError('invalid checksum address for contract')
 
+    transfer_from_address = None
+    if config.get('_FROM'):
+        transfer_from_address = to_checksum_address(config.get('_FROM'))
+        if not config.true('_UNSAFE') and transfer_from_address != add_0x(config.get('_FROM')):
+            raise ValueError('invalid checksum address for "from" argument')
+
+    check_balance_address = None
+    
     if logg.isEnabledFor(logging.DEBUG):
-        sender_balance = balance(g, token_address, signer_address, id_generator=rpc.id_generator)
+        if transfer_from_address:
+            check_balance_address = transfer_from_address
+        else:
+            check_balance_address = signer_address
+        sender_balance = balance(g, token_address, check_balance_address, id_generator=rpc.id_generator)
         recipient_balance = balance(g, token_address, recipient, id_generator=rpc.id_generator)
-        logg.debug('sender {} balance before: {}'.format(signer_address, sender_balance))
+        logg.debug('sender {} balance before: {}'.format(check_balance_address, sender_balance))
         logg.debug('recipient {} balance before: {}'.format(recipient, recipient_balance))
 
-    (tx_hash_hex, o) = g.transfer(token_address, signer_address, recipient, value, id_generator=rpc.id_generator)
+    if transfer_from_address and not is_same_address(transfer_from_address, signer_address):
+        (tx_hash_hex, o) = g.transfer_from(token_address, signer_address, transfer_from_address, recipient, value, id_generator=rpc.id_generator)
+    else:
+        (tx_hash_hex, o) = g.transfer(token_address, signer_address, recipient, value, id_generator=rpc.id_generator)
 
     if send:
         conn.do(o)
         if block_last:
             r = conn.wait(tx_hash_hex)
             if logg.isEnabledFor(logging.DEBUG):
-                sender_balance = balance(g, token_address, signer_address, id_generator=rpc.id_generator)
+                sender_balance = balance(g, token_address, check_balance_address, id_generator=rpc.id_generator)
                 recipient_balance = balance(g, token_address, recipient, id_generator=rpc.id_generator)
-                logg.debug('sender {} balance after: {}'.format(signer_address, sender_balance))
+                logg.debug('sender {} balance after: {}'.format(check_balance_address, sender_balance))
                 logg.debug('recipient {} balance after: {}'.format(recipient, recipient_balance))
             if r['status'] == 0:
                 logg.critical('VM revert. Wish I could tell you more')

python/giftable_erc20_token/data/GiftableToken.json

@@ -1 +1 @@
-[{"inputs":[{"internalType":"string","name":"_name","type":"string"},{"internalType":"string","name":"_symbol","type":"string"},{"internalType":"uint8","name":"_decimals","type":"uint8"}],"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_owner","type":"address"},{"indexed":true,"internalType":"address","name":"_spender","type":"address"},{"indexed":false,"internalType":"uint256","name":"_value","type":"uint256"}],"name":"Approval","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_minter","type":"address"},{"indexed":true,"internalType":"address","name":"_beneficiary","type":"address"},{"indexed":false,"internalType":"uint256","name":"_value","type":"uint256"}],"name":"Mint","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_from","type":"address"},{"indexed":true,"internalType":"address","name":"_to","type":"address"},{"indexed":false,"internalType":"uint256","name":"_value","type":"uint256"}],"name":"Transfer","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_from","type":"address"},{"indexed":true,"internalType":"address","name":"_to","type":"address"},{"indexed":true,"internalType":"address","name":"_spender","type":"address"},{"indexed":false,"internalType":"uint256","name":"_value","type":"uint256"}],"name":"TransferFrom","type":"event"},{"inputs":[{"internalType":"address","name":"_minter","type":"address"}],"name":"addMinter","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"","type":"address"},{"internalType":"address","name":"","type":"address"}],"name":"allowance","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_spender","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"approve","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"","type":"address"}],"name":"balanceOf","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"decimals","outputs":[{"internalType":"uint8","name":"","type":"uint8"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_to","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"mintTo","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"name","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"owner","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_minter","type":"address"}],"name":"removeMinter","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"bytes4","name":"_sum","type":"bytes4"}],"name":"supportsInterface","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"symbol","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"totalSupply","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_to","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"transfer","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_from","type":"address"},{"internalType":"address","name":"_to","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"transferFrom","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_newOwner","type":"address"}],"name":"transferOwnership","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"}]
+[{"inputs":[{"internalType":"string","name":"_name","type":"string"},{"internalType":"string","name":"_symbol","type":"string"},{"internalType":"uint8","name":"_decimals","type":"uint8"}],"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_owner","type":"address"},{"indexed":true,"internalType":"address","name":"_spender","type":"address"},{"indexed":false,"internalType":"uint256","name":"_value","type":"uint256"}],"name":"Approval","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_minter","type":"address"},{"indexed":true,"internalType":"address","name":"_beneficiary","type":"address"},{"indexed":false,"internalType":"uint256","name":"_value","type":"uint256"}],"name":"Mint","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_from","type":"address"},{"indexed":true,"internalType":"address","name":"_to","type":"address"},{"indexed":false,"internalType":"uint256","name":"_value","type":"uint256"}],"name":"Transfer","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_from","type":"address"},{"indexed":true,"internalType":"address","name":"_to","type":"address"},{"indexed":true,"internalType":"address","name":"_spender","type":"address"},{"indexed":false,"internalType":"uint256","name":"_value","type":"uint256"}],"name":"TransferFrom","type":"event"},{"inputs":[{"internalType":"address","name":"_minter","type":"address"}],"name":"addMinter","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_minter","type":"address"}],"name":"addWriter","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"","type":"address"},{"internalType":"address","name":"","type":"address"}],"name":"allowance","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_spender","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"approve","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"","type":"address"}],"name":"balanceOf","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"decimals","outputs":[{"internalType":"uint8","name":"","type":"uint8"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_minter","type":"address"}],"name":"deleteWriter","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_to","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"mintTo","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"name","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"owner","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_minter","type":"address"}],"name":"removeMinter","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"bytes4","name":"_sum","type":"bytes4"}],"name":"supportsInterface","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"symbol","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"totalSupply","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_to","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"transfer","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_from","type":"address"},{"internalType":"address","name":"_to","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"transferFrom","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_newOwner","type":"address"}],"name":"transferOwnership","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"}]

python/run_tests.sh

@@ -2,6 +2,8 @@
 
 set -e
 set -x
+default_pythonpath=$PYTHONPATH:.
+export PYTHONPATH=${default_pythonpath:-.}
 for f in `ls tests/*.py`; do
 	python $f
 	if [ $? -gt 0 ]; then

python/setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = eth-erc20
-version = 0.1.9
+version = 0.1.11
 description = ERC20 interface and simple contract with deployment script that lets any address mint and gift itself tokens.
 author = Louis Holbrook
 author_email = dev@holbrook.no

solidity/GiftableToken.json

@@ -1 +1 @@
-[{"inputs":[{"internalType":"string","name":"_name","type":"string"},{"internalType":"string","name":"_symbol","type":"string"},{"internalType":"uint8","name":"_decimals","type":"uint8"}],"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_owner","type":"address"},{"indexed":true,"internalType":"address","name":"_spender","type":"address"},{"indexed":false,"internalType":"uint256","name":"_value","type":"uint256"}],"name":"Approval","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_minter","type":"address"},{"indexed":true,"internalType":"address","name":"_beneficiary","type":"address"},{"indexed":false,"internalType":"uint256","name":"_value","type":"uint256"}],"name":"Mint","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_from","type":"address"},{"indexed":true,"internalType":"address","name":"_to","type":"address"},{"indexed":false,"internalType":"uint256","name":"_value","type":"uint256"}],"name":"Transfer","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_from","type":"address"},{"indexed":true,"internalType":"address","name":"_to","type":"address"},{"indexed":true,"internalType":"address","name":"_spender","type":"address"},{"indexed":false,"internalType":"uint256","name":"_value","type":"uint256"}],"name":"TransferFrom","type":"event"},{"inputs":[{"internalType":"address","name":"_minter","type":"address"}],"name":"addMinter","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"","type":"address"},{"internalType":"address","name":"","type":"address"}],"name":"allowance","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_spender","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"approve","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"","type":"address"}],"name":"balanceOf","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"decimals","outputs":[{"internalType":"uint8","name":"","type":"uint8"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_to","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"mintTo","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"name","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"owner","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_minter","type":"address"}],"name":"removeMinter","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"bytes4","name":"_sum","type":"bytes4"}],"name":"supportsInterface","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"symbol","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"totalSupply","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_to","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"transfer","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_from","type":"address"},{"internalType":"address","name":"_to","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"transferFrom","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_newOwner","type":"address"}],"name":"transferOwnership","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"}]
+[{"inputs":[{"internalType":"string","name":"_name","type":"string"},{"internalType":"string","name":"_symbol","type":"string"},{"internalType":"uint8","name":"_decimals","type":"uint8"}],"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_owner","type":"address"},{"indexed":true,"internalType":"address","name":"_spender","type":"address"},{"indexed":false,"internalType":"uint256","name":"_value","type":"uint256"}],"name":"Approval","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_minter","type":"address"},{"indexed":true,"internalType":"address","name":"_beneficiary","type":"address"},{"indexed":false,"internalType":"uint256","name":"_value","type":"uint256"}],"name":"Mint","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_from","type":"address"},{"indexed":true,"internalType":"address","name":"_to","type":"address"},{"indexed":false,"internalType":"uint256","name":"_value","type":"uint256"}],"name":"Transfer","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_from","type":"address"},{"indexed":true,"internalType":"address","name":"_to","type":"address"},{"indexed":true,"internalType":"address","name":"_spender","type":"address"},{"indexed":false,"internalType":"uint256","name":"_value","type":"uint256"}],"name":"TransferFrom","type":"event"},{"inputs":[{"internalType":"address","name":"_minter","type":"address"}],"name":"addMinter","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_minter","type":"address"}],"name":"addWriter","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"","type":"address"},{"internalType":"address","name":"","type":"address"}],"name":"allowance","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_spender","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"approve","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"","type":"address"}],"name":"balanceOf","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"decimals","outputs":[{"internalType":"uint8","name":"","type":"uint8"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_minter","type":"address"}],"name":"deleteWriter","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_to","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"mintTo","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"name","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"owner","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_minter","type":"address"}],"name":"removeMinter","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"bytes4","name":"_sum","type":"bytes4"}],"name":"supportsInterface","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"symbol","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"totalSupply","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_to","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"transfer","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_from","type":"address"},{"internalType":"address","name":"_to","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"transferFrom","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_newOwner","type":"address"}],"name":"transferOwnership","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"}]

solidity/GiftableToken.sol

@@ -24,7 +24,7 @@ contract GiftableToken {
 	event Transfer(address indexed _from, address indexed _to, uint256 _value);
 	event TransferFrom(address indexed _from, address indexed _to, address indexed _spender, uint256 _value);
 	event Approval(address indexed _owner, address indexed _spender, uint256 _value);
-	event Mint(address indexed _minter, address indexed _beneficiary, uint256 _value);
+	event Mint(address indexed _minter, address indexed _beneficiary, uint256 _value); // Minter
 
 	constructor(string memory _name, string memory _symbol, uint8 _decimals) public {
 		owner = msg.sender;
@@ -34,6 +34,7 @@ contract GiftableToken {
 		minters[msg.sender] = true;
 	}
 
+	// Implements Minter
 	function mintTo(address _to, uint256 _value) public returns (bool) {
 		require(minters[msg.sender]);
 
@@ -53,6 +54,11 @@ contract GiftableToken {
 		return true;
 	}
 
+	// Implements Writer
+	function addWriter(address _minter) public returns (bool) {
+		return addMinter(_minter);
+	}
+
 	function removeMinter(address _minter) public returns (bool) {
 		require(msg.sender == owner || msg.sender == _minter);
 
@@ -61,6 +67,11 @@ contract GiftableToken {
 		return true;
 	}
 
+	// Implements Writer
+	function deleteWriter(address _minter) public returns (bool) {
+		return removeMinter(_minter);
+	}
+
 	// Implements ERC20
 	function transfer(address _to, uint256 _value) public returns (bool) {
 		require(balanceOf[msg.sender] >= _value);
@@ -93,6 +104,7 @@ contract GiftableToken {
 
 	// Implements EIP173
 	function transferOwnership(address _newOwner) public returns (bool) {
+		require(msg.sender == owner);
 		owner = _newOwner;
 	}
 
@@ -107,6 +119,9 @@ contract GiftableToken {
 		if (_sum == 0x01ffc9a7) { // EIP165
 			return true;
 		}
+		if (_sum == 0x80c84bd6) { // Writer
+			return true;
+		}
 		if (_sum == 0x9493f8b2) { // EIP173
 			return true;
 		}