Mdthbs

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comparing two addresses

Are there well-solved and simple storage patterns for Solidity?Error: “message”:“function ”Ballot“ arguments must include ”proposalNames“”}This contract does not implement all functions and thus cannot be createdA function declared payable is throwing a VMerror:revert in RemixModifier condition always falseHow do I send tokens with EthereumTesterProvider?How is gas adjusted for a transfer in solidity?How to state private keys when using node.js and ethereum to run a contract?remix ERC223: This contract does not implement all functions and thus cannot be createdCollecting ERC20 balances from multiple addresses?Getting Error as parser error:expected identifier, got event

.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty{ margin-bottom:0;
}

1

I'am trying to create a modifier that allows certain accounts to execute functions.

 address[] authorized; 

       function verify (address adrs) internal view returns (bool)

{

    bool exist;

    uint  j=authorized.length;

    uint i =0;

    exist = false;

    address[] memory adrss;

    while (i<j){

        uint x =0;

        if (adrss ==address[i]){

            bool = true;

        }

        i++;

    }

    return exist;

}







  modifie allowed (address adrs){

        require  (  verify(adrs)==true);

                    _; }

anyone how has an idea?

solidity contract-design dapps ethereumjs

share|improve this question

edited 9 hours ago

Rob Hitchens - B9lab

31.4k77 gold badges4646 silver badges8787 bronze badges

asked 12 hours ago

MS BMS B

3255 bronze badges

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  Hi there. I haven't tried it, but it's clear the above code doesn't compile. Is your question "How do I get this code to compile?" or, more generally, "What is the best way to implement an ACL?". Please be more specific with your question: ethereum.stackexchange.com/help/how-to-ask
  
  – Richard Horrocks
  12 hours ago
  

  
  
  
  

add a comment | 

1

I'am trying to create a modifier that allows certain accounts to execute functions.

 address[] authorized; 

       function verify (address adrs) internal view returns (bool)

{

    bool exist;

    uint  j=authorized.length;

    uint i =0;

    exist = false;

    address[] memory adrss;

    while (i<j){

        uint x =0;

        if (adrss ==address[i]){

            bool = true;

        }

        i++;

    }

    return exist;

}







  modifie allowed (address adrs){

        require  (  verify(adrs)==true);

                    _; }

anyone how has an idea?

solidity contract-design dapps ethereumjs

share|improve this question

edited 9 hours ago

Rob Hitchens - B9lab

31.4k77 gold badges4646 silver badges8787 bronze badges

asked 12 hours ago

MS BMS B

3255 bronze badges

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  Hi there. I haven't tried it, but it's clear the above code doesn't compile. Is your question "How do I get this code to compile?" or, more generally, "What is the best way to implement an ACL?". Please be more specific with your question: ethereum.stackexchange.com/help/how-to-ask
  
  – Richard Horrocks
  12 hours ago
  

  
  
  
  

add a comment | 

I'am trying to create a modifier that allows certain accounts to execute functions.

 address[] authorized; 

       function verify (address adrs) internal view returns (bool)

{

    bool exist;

    uint  j=authorized.length;

    uint i =0;

    exist = false;

    address[] memory adrss;

    while (i<j){

        uint x =0;

        if (adrss ==address[i]){

            bool = true;

        }

        i++;

    }

    return exist;

}







  modifie allowed (address adrs){

        require  (  verify(adrs)==true);

                    _; }

anyone how has an idea?

solidity contract-design dapps ethereumjs

share|improve this question

edited 9 hours ago

Rob Hitchens - B9lab

31.4k77 gold badges4646 silver badges8787 bronze badges

asked 12 hours ago

MS BMS B

3255 bronze badges

 address[] authorized; 

       function verify (address adrs) internal view returns (bool)

{

    bool exist;

    uint  j=authorized.length;

    uint i =0;

    exist = false;

    address[] memory adrss;

    while (i<j){

        uint x =0;

        if (adrss ==address[i]){

            bool = true;

        }

        i++;

    }

    return exist;

}







  modifie allowed (address adrs){

        require  (  verify(adrs)==true);

                    _; }

share|improve this question

edited 9 hours ago

Rob Hitchens - B9lab

31.4k77 gold badges4646 silver badges8787 bronze badges

asked 12 hours ago

MS BMS B

3255 bronze badges

share|improve this question

edited 9 hours ago

Rob Hitchens - B9lab

31.4k77 gold badges4646 silver badges8787 bronze badges

asked 12 hours ago

MS BMS B

3255 bronze badges

edited 9 hours ago

Rob Hitchens - B9lab

31.4k77 gold badges4646 silver badges8787 bronze badges

edited 9 hours ago

Rob Hitchens - B9lab

31.4k77 gold badges4646 silver badges8787 bronze badges

asked 12 hours ago

MS BMS B

3255 bronze badges

asked 12 hours ago

MS BMS B

3255 bronze badges

3 Answers
3

active

oldest

votes

3

You should avoid iterating the list of permitted accounts. It's an expensive approach that doesn't scale and it has a lot of moving parts.

Consider instead using a mapping. This is a namespace where all the uninitialized indexes return false, 0, empty, depending on type. For example:

mapping(address => bool) public whitelist; returns true or false for each address, and you can set/get without iterating.

pragma solidity 0.5.1;



contract SimpleWhitelist {



    address public owner;

    mapping(address => bool) public whitelist;



    event LogProtected(address sender);



    modifier onlyOwner {

        require(msg.sender == owner, "You are not the owner.");

        _;

    }



    modifier onlyWhitelist {

        require(whitelist[msg.sender], "You are not whitelisted.");

        _;

    }



    function setPermission(address user, bool isAllowed) public onlyOwner {

        whitelist[user] = isAllowed;

    }



    function protected() public onlyWhitelist {

        emit LogProtected(msg.sender);

    }    

}

There are more advanced ways to store the list of whitelisted addresses: Are there well-solved and simple storage patterns for Solidity? and de facto standard implementations of the Ownable concept but I wanted to keep this as simple as possible.

1. Only the owner is allowed to grant/revoke permission.


2. Only whitelisted addresses are allowed to run protected(). It will emit an event on success.

Hope it helps.

share|improve this answer

answered 12 hours ago

Rob Hitchens - B9labRob Hitchens - B9lab

31.4k77 gold badges4646 silver badges8787 bronze badges

add a comment | 

2

You are making a fundamental mistake which makes it all seem much harder than it really is.
Instead of an array, your should use a mapping(address => bool), let's call it whitelisted, since it contains booleans.

Add people in the whitelist like this: whitelisted[_address] = true;

then in your modifier, you can simply do this:

require(whitelist[_address])

share|improve this answer

edited 7 hours ago

answered 11 hours ago

blackscaleblackscale

4344 bronze badges

New contributor

blackscale is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  No need to convert through uint160). if(addr1 == addr2) { ... should work if both are addresses.
  
  – Rob Hitchens - B9lab
  10 hours ago
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  You are correct, that trick is useful for comparing short Strings cheaply, and I made some confusion. I edited out that part, as anyway it was slightly besides the OP's topic.
  
  – blackscale
  7 hours ago
  
  
  

  
  
  
  

add a comment | 

2

I recommend that you look at the OpenZeppelin guide on Access Control, specifically the section on Role-Based Access Control as using Roles from OpenZeppelin appear to meet your needs.
https://docs.openzeppelin.org/v2.3.0/access-control

For questions on use, you can also ask in the community forum https://forum.zeppelin.solutions/

share|improve this answer

answered 3 hours ago

abcoathupabcoathup

30077 bronze badges

add a comment | 

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3

You should avoid iterating the list of permitted accounts. It's an expensive approach that doesn't scale and it has a lot of moving parts.

Consider instead using a mapping. This is a namespace where all the uninitialized indexes return false, 0, empty, depending on type. For example:

mapping(address => bool) public whitelist; returns true or false for each address, and you can set/get without iterating.

pragma solidity 0.5.1;



contract SimpleWhitelist {



    address public owner;

    mapping(address => bool) public whitelist;



    event LogProtected(address sender);



    modifier onlyOwner {

        require(msg.sender == owner, "You are not the owner.");

        _;

    }



    modifier onlyWhitelist {

        require(whitelist[msg.sender], "You are not whitelisted.");

        _;

    }



    function setPermission(address user, bool isAllowed) public onlyOwner {

        whitelist[user] = isAllowed;

    }



    function protected() public onlyWhitelist {

        emit LogProtected(msg.sender);

    }    

}

There are more advanced ways to store the list of whitelisted addresses: Are there well-solved and simple storage patterns for Solidity? and de facto standard implementations of the Ownable concept but I wanted to keep this as simple as possible.

1. Only the owner is allowed to grant/revoke permission.


2. Only whitelisted addresses are allowed to run protected(). It will emit an event on success.

Hope it helps.

share|improve this answer

answered 12 hours ago

Rob Hitchens - B9labRob Hitchens - B9lab

31.4k77 gold badges4646 silver badges8787 bronze badges

add a comment | 

3

You should avoid iterating the list of permitted accounts. It's an expensive approach that doesn't scale and it has a lot of moving parts.

Consider instead using a mapping. This is a namespace where all the uninitialized indexes return false, 0, empty, depending on type. For example:

mapping(address => bool) public whitelist; returns true or false for each address, and you can set/get without iterating.

pragma solidity 0.5.1;



contract SimpleWhitelist {



    address public owner;

    mapping(address => bool) public whitelist;



    event LogProtected(address sender);



    modifier onlyOwner {

        require(msg.sender == owner, "You are not the owner.");

        _;

    }



    modifier onlyWhitelist {

        require(whitelist[msg.sender], "You are not whitelisted.");

        _;

    }



    function setPermission(address user, bool isAllowed) public onlyOwner {

        whitelist[user] = isAllowed;

    }



    function protected() public onlyWhitelist {

        emit LogProtected(msg.sender);

    }    

}

There are more advanced ways to store the list of whitelisted addresses: Are there well-solved and simple storage patterns for Solidity? and de facto standard implementations of the Ownable concept but I wanted to keep this as simple as possible.

1. Only the owner is allowed to grant/revoke permission.


2. Only whitelisted addresses are allowed to run protected(). It will emit an event on success.

Hope it helps.

share|improve this answer

answered 12 hours ago

Rob Hitchens - B9labRob Hitchens - B9lab

31.4k77 gold badges4646 silver badges8787 bronze badges

add a comment | 

You should avoid iterating the list of permitted accounts. It's an expensive approach that doesn't scale and it has a lot of moving parts.

Consider instead using a mapping. This is a namespace where all the uninitialized indexes return false, 0, empty, depending on type. For example:

mapping(address => bool) public whitelist; returns true or false for each address, and you can set/get without iterating.

pragma solidity 0.5.1;



contract SimpleWhitelist {



    address public owner;

    mapping(address => bool) public whitelist;



    event LogProtected(address sender);



    modifier onlyOwner {

        require(msg.sender == owner, "You are not the owner.");

        _;

    }



    modifier onlyWhitelist {

        require(whitelist[msg.sender], "You are not whitelisted.");

        _;

    }



    function setPermission(address user, bool isAllowed) public onlyOwner {

        whitelist[user] = isAllowed;

    }



    function protected() public onlyWhitelist {

        emit LogProtected(msg.sender);

    }    

}

There are more advanced ways to store the list of whitelisted addresses: Are there well-solved and simple storage patterns for Solidity? and de facto standard implementations of the Ownable concept but I wanted to keep this as simple as possible.

1. Only the owner is allowed to grant/revoke permission.


2. Only whitelisted addresses are allowed to run protected(). It will emit an event on success.

Hope it helps.

share|improve this answer

answered 12 hours ago

Rob Hitchens - B9labRob Hitchens - B9lab

31.4k77 gold badges4646 silver badges8787 bronze badges

pragma solidity 0.5.1;



contract SimpleWhitelist {



    address public owner;

    mapping(address => bool) public whitelist;



    event LogProtected(address sender);



    modifier onlyOwner {

        require(msg.sender == owner, "You are not the owner.");

        _;

    }



    modifier onlyWhitelist {

        require(whitelist[msg.sender], "You are not whitelisted.");

        _;

    }



    function setPermission(address user, bool isAllowed) public onlyOwner {

        whitelist[user] = isAllowed;

    }



    function protected() public onlyWhitelist {

        emit LogProtected(msg.sender);

    }    

}

share|improve this answer

answered 12 hours ago

Rob Hitchens - B9labRob Hitchens - B9lab

31.4k77 gold badges4646 silver badges8787 bronze badges

answered 12 hours ago

Rob Hitchens - B9labRob Hitchens - B9lab

31.4k77 gold badges4646 silver badges8787 bronze badges

answered 12 hours ago

Rob Hitchens - B9labRob Hitchens - B9lab

31.4k77 gold badges4646 silver badges8787 bronze badges

2

You are making a fundamental mistake which makes it all seem much harder than it really is.
Instead of an array, your should use a mapping(address => bool), let's call it whitelisted, since it contains booleans.

Add people in the whitelist like this: whitelisted[_address] = true;

then in your modifier, you can simply do this:

require(whitelist[_address])

share|improve this answer

edited 7 hours ago

answered 11 hours ago

blackscaleblackscale

4344 bronze badges

New contributor

blackscale is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  No need to convert through uint160). if(addr1 == addr2) { ... should work if both are addresses.
  
  – Rob Hitchens - B9lab
  10 hours ago
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  You are correct, that trick is useful for comparing short Strings cheaply, and I made some confusion. I edited out that part, as anyway it was slightly besides the OP's topic.
  
  – blackscale
  7 hours ago
  
  
  

  
  
  
  

add a comment | 

2

You are making a fundamental mistake which makes it all seem much harder than it really is.
Instead of an array, your should use a mapping(address => bool), let's call it whitelisted, since it contains booleans.

Add people in the whitelist like this: whitelisted[_address] = true;

then in your modifier, you can simply do this:

require(whitelist[_address])

share|improve this answer

edited 7 hours ago

answered 11 hours ago

blackscaleblackscale

4344 bronze badges

New contributor

blackscale is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  No need to convert through uint160). if(addr1 == addr2) { ... should work if both are addresses.
  
  – Rob Hitchens - B9lab
  10 hours ago
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  You are correct, that trick is useful for comparing short Strings cheaply, and I made some confusion. I edited out that part, as anyway it was slightly besides the OP's topic.
  
  – blackscale
  7 hours ago
  
  
  

  
  
  
  

add a comment | 

You are making a fundamental mistake which makes it all seem much harder than it really is.
Instead of an array, your should use a mapping(address => bool), let's call it whitelisted, since it contains booleans.

Add people in the whitelist like this: whitelisted[_address] = true;

then in your modifier, you can simply do this:

require(whitelist[_address])

share|improve this answer

edited 7 hours ago

answered 11 hours ago

blackscaleblackscale

4344 bronze badges

New contributor

blackscale is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

require(whitelist[_address])

share|improve this answer

edited 7 hours ago

answered 11 hours ago

blackscaleblackscale

4344 bronze badges

New contributor

blackscale is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

answered 11 hours ago

blackscaleblackscale

4344 bronze badges

New contributor

blackscale is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

answered 11 hours ago

blackscaleblackscale

4344 bronze badges

2

I recommend that you look at the OpenZeppelin guide on Access Control, specifically the section on Role-Based Access Control as using Roles from OpenZeppelin appear to meet your needs.
https://docs.openzeppelin.org/v2.3.0/access-control

For questions on use, you can also ask in the community forum https://forum.zeppelin.solutions/

share|improve this answer

answered 3 hours ago

abcoathupabcoathup

30077 bronze badges

add a comment | 

2

I recommend that you look at the OpenZeppelin guide on Access Control, specifically the section on Role-Based Access Control as using Roles from OpenZeppelin appear to meet your needs.
https://docs.openzeppelin.org/v2.3.0/access-control

For questions on use, you can also ask in the community forum https://forum.zeppelin.solutions/

share|improve this answer

answered 3 hours ago

abcoathupabcoathup

30077 bronze badges

add a comment | 

I recommend that you look at the OpenZeppelin guide on Access Control, specifically the section on Role-Based Access Control as using Roles from OpenZeppelin appear to meet your needs.
https://docs.openzeppelin.org/v2.3.0/access-control

For questions on use, you can also ask in the community forum https://forum.zeppelin.solutions/

share|improve this answer

answered 3 hours ago

abcoathupabcoathup

30077 bronze badges

share|improve this answer

answered 3 hours ago

abcoathupabcoathup

30077 bronze badges

answered 3 hours ago

abcoathupabcoathup

30077 bronze badges

answered 3 hours ago

abcoathupabcoathup

30077 bronze badges