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Author: 0xlucian

Governance/AccessControl.md

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+# Access Control
+
+Access control play a crucial role in our Governance model. We use it to restrict certain functions to be called only from one account or list of accounts (EOA or Contract Accounts).
+
+
+
+
+# Access Control Manager
+The implementation of our AC Management we implemented [**AccessControlManager.sol**](https://github.com/VenusProtocol/isolated-pools/blob/main/contracts/Governance/AccessControlManager.sol)  which is a contract that inherits  [**@openzeppelin/contracts/access/AccessControl.sol**](https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/access/AccessControl.sol) as a base of our role management logic.
+Roles are built by hashing the contract address and its function signature.
+E.g We have a Contract A with function A.try() which is guarded by ACM.
+Calling giveRolePermission for account B will basically do:
+1. compute keccak256({addrress-of-a},{function-sig-of-try()})
+2. add the computed role to the roles of account B
+3. Account B now can call try() of Contract A
+
+**NOTE:** because of the existence of factory contracts, in some cases we don't need that granular permissions (e.g in PoolRegistry). So we introduced **DEFAULT_ADMIN_FUNCTION_ROLE**.
+This role is computed the same way, but instead of computing `keccak256({addrress-of-a},{function-sig-of-try()})`, we do `keccak256({zero-address},{function-sig-of-try()})`. 
+If we consider the same case above and give account B the **DEFAULT_ADMIN_FUNCTION_ROLE** , account B will have permissions to call try() function on any contract that is guarded by ACM, not only contract A.
+Lets' take a look at each interface function of the contract:
+
+# Solidity API
+
+  
+
+## AccessControlManager
+
+  
+
+This contract is a wrapper of OpenZeppelin AccessControl
+
+extending it in a way to standardise access control
+
+within Venus Smart Contract Ecosystem_
+
+  
+
+### constructor
+
+  
+
+```solidity
+
+constructor() public
+
+```
+
+  
+
+### isAllowedToCall
+
+  
+
+```solidity
+
+function isAllowedToCall(address caller, string functionSig) public view returns (bool)
+
+```
+
+  
+
+Verifies if the given account can call a praticular contract's function
+
+  
+
+_Since the contract is calling itself this function, we can get contracts address with msg.sender_
+
+  
+
+#### Parameters
+
+  
+
+| Name | Type | Description |
+
+| ---- | ---- | ----------- |
+
+| caller | address | contract for which call permissions will be checked |
+
+| functionSig | string | signature e.g. "functionName(uint,bool)" |
+
+  
+
+#### Return Values
+
+  
+
+| Name | Type | Description |
+
+| ---- | ---- | ----------- |
+
+| [0] | bool | false if the user account cannot call the particular contract function |
+
+  
+
+### giveCallPermission
+
+  
+
+```solidity
+
+function giveCallPermission(address contractAddress, string functionSig, address accountToPermit) public
+
+```
+
+  
+
+Gives a function call permission to one single account
+
+  
+
+_this function can be called only from Role Admin or DEFAULT_ADMIN_ROLE
+
+May emit a {RoleGranted} event._
+
+  
+
+#### Parameters
+
+  
+
+| Name | Type | Description |
+
+| ---- | ---- | ----------- |
+
+| contractAddress | address | address of contract for which call permissions will be granted NOTE: if contractAddress is zero address, we give the account DEFAULT_ADMIN_ROLE, meaning that this account can access the certain function on ANY contract managed by this ACL |
+
+| functionSig | string | signature e.g. "functionName(uint,bool)" |
+
+| accountToPermit | address | account that will be given access to the contract function |
+
+  
+
+### revokeCallPermission
+
+  
+
+```solidity
+
+function revokeCallPermission(address contractAddress, string functionSig, address accountToRevoke) public
+
+```
+
+  
+
+Revokes an account's permission to a particular function call
+
+  
+
+_this function can be called only from Role Admin or DEFAULT_ADMIN_ROLE
+
+May emit a {RoleRevoked} event._
+
+  
+
+#### Parameters
+
+  
+
+| Name | Type | Description |
+
+| ---- | ---- | ----------- |
+
+| contractAddress | address | address of contract for which call permissions will be revoked |
+
+| functionSig | string | signature e.g. "functionName(uint,bool)" |
+
+| accountToRevoke | address | |