Authorizable Smart Contract

This contract allows minimalistic governance.

Levels

Authorizable allows an unlimited number of levels.

Any authorized address has an assigned level.

By default, Authorizable has maxLevel = 64 and authorizerLevel = 56. The first is the top level accepted. The second is the minimum level requested to an address to be allowed to authorize other addresses.

The function setLevels allows to set the variables above, but only when there are no authorized addresses. After than someone has been authorized, the default levels cannot be changed to avoid unfixable errors. To change them, you should call deAuthorizeAll and restart :-(

Any level is an uint, but you can extend the contract and add helper variables, like, for example:

uint public operatorLevel = 6;
uint public teamManagerLevel = 10;
uint public CTOLevel = 32;
uint public CEOLevel = 50;

Modifiers

Authorizable offers many modifiers, in order to cover all the simple cases. Extending the contract, you can add more complex modifiers. Here is the list:

onlyAuthorized allows any authorized address

onlyAuthorizedAtLevel(uint _level) allows only authorized addresses at level l

onlyAuthorizedAtLevels(uint[] _levels) allows only authorized addresses at any of levels listed in the array ll

onlyAuthorizedAtLevelsWithin(uint minLevel, uint maxLevel) allows only authorized addresses at level in between the interval

The followings are the same as above but allow also the owner:

onlyOwnerOrAuthorized
onlyOwnerOrAuthorizedAtLevel
onlyOwnerOrAuthorizedAtLevels
onlyOwnerOrAuthorizedAtLevelsWithin

Finally

onlyAuthorizer allows owner and authorized addresses at level >= authorizerLevel. It's equivalent to onlyOwnerOrAuthorizedAtLevelsWithin(authorizerLevel, maxLevel).

Examples

To allow only level >= 10, you can set a function like this

function some() onlyAuthorizedAtLevelsWithin(10, maxLevel) {
  ...
}

To allow only level 3 and 6 to call a specifif function, you can do something like

uint[] public levels = [3, 6]

function some() onlyAuthorizedAtLevels(levels) {
  ...
}

Notice that if you try to do

function some() onlyAuthorizedAtLevels([3, 6]) {
  ...
}

you will have a compilation error because [3, 6] is taken as a uint2[] array and is not implicitly convertible to uint[].

Installation and tests

First off, you need to install globally Truffle and Ganachi-cli

npm install -g ganachi-cli truffle

After, you can complete the installation with

npm install && truffle install

Finally, you start the test server in one terminal with

ganachi-cli

and in another terminal

truffle test

Usage

To use Authorizable in a Truffle project install it

npm i -D authorizable

and, in you contract, import it like the following example

pragma solidity ^0.4.18;


import 'authorizable/contracts/Authorizable.sol';

contract Contract is Authorizable {
  // your code here
}

Alternatively, save the flattened/Authorizable.sol contract wherever you need it.

API

authorize(address _address, uint _level) onlyAuthorizer
Allows any authorizer (owner and levels >= authorizerLevel) to authorize a wallet at a specific level, or to revocate the authorization if the _level is 0.

authorizeBatch(address[] _addresses, uint _level) onlyAuthorizer
Allows any authorizer to authorize a list of wallets at a specific level (useful, for example, during whitelisting processes).

deAuthorizeAll() onlyOwner
Allows the owner to revocate authorization to all the authorized wallets. This function has a safety check of the gasleft() to avoid going out of gas. If, for example, you are trying to remove all the wallets that where whitelisted to participate in an ICO, you could have 10,000 wallets there. In this case the function would require too much gas and it would it the gas limit resulting in a not-executable function.
To avoid this, the function interrupts the process when there is no more gas left, requiring that you call it again and again until you don't reach the wanted result.

deAuthorizeAllAtLevel(uint _level) onlyAuthorizer
Allows any authorizer to revocate the authorization to any wallet at the specified level.

deAuthorize() onlyAuthorized
Allows any authorized wallets to revocate its own authorization.

setLevels(uint _maxLevel, uint _authorizerLevel) onlyOwner
Allows to set the default levels. This can be done only if totalAuthorized is equal to zero, to avoid conflicts and unpredictable errors.

setSelfRevoke(bool _selfRevoke) onlyOwner
Allows to decide if an authorized wallet is able to revoke its own authorization. By default, it is allowed.

License

MIT.

Copyright

(c) 2018, Francesco Sullo [email protected], 0xNIL