(remember to git submodule update --init --recursive after cloning)

Token with revocable transfer restrictions

Summary

• Based on solmate code.
• Adds authorizer mint.
• Users can burn their tokens.
• Requires authentication on transfer, transferFrom and mint.
• Can remove authentication later.
• Editable script/deploy.sol to set token name,symbol & owner.

The Auth contract differs from solmate's vanilla Auth : authority is itself. This saves a SLOAD and a bit more.

The RolesAuthority contract differs from solmate's vanilla RoleAuthority : it inherits the modified Auth and always has itself as a target.

The contract is structured as inheriting from ERC20 and RolesAuthority. It defines itself as its own authority, so authenticated methods call this.canCall to check authorization.

The owner is given in the constructor and the owner can mint, and transfer at will. Once the proper authorizations have been setup, the owner should be set to 0.

We decide on the following roles:

Role	Can call
0	transfer, transferFrom
1	mint

To set roles, owner should call (once):

token.setRoleCapability(0,Token.transfer.selector,true);
token.setRoleCapability(0,Token.transferFrom.selector,true);
token.setRoleCapability(1,Token.mint.selector,true);

This will be done automatically when calling deploy.sol

To give transfer rights to an address addr, owner should call:

token.setUserRole(addr,0,true);

To enable transfers for everyone, owner should call:

token.setPublicCapability(Token.transfer.selector,true);
token.setPublicCapability(Token.transferFrom.selector,true);

Compared to regular transfers, there will then be 1 extra SLOAD (loading the boolean isCapabilityPublic(address(token), Token.transfer*.selector)).

To give mint rights, to an address addr, owner should call

token.setUserRole(addr,1,true); // for mint

To remove itself, owner should call (⚠️ There is no going back ⚠):

token.setOwner(address(0));

Audits

The code has been audited by Omniscia and the report can be found online or in this file Morpho_Omniscia.