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12 votes
Accepted

Restricted Access / Authentication for a Remote Geth Node

OK I figured this out, using basic HTTP/HTTPs auth. Posting in case this helps anyone else: AWS: disabled inbound TCP access to 8545 port (in AWS security groups) Added auth_basic in nginx Used ...
carlolm's user avatar
  • 2,326
9 votes
Accepted

What are the best practices to allow user signup and login for a dapp?

AFAIK it's always easy and good to use the PGP key mechanism for user authentication in DAPPs built using Ethereum. It's possible to use the account address as the username and to let the user sign ...
Achala Dissanayake's user avatar
5 votes
Accepted

How to authenticate with an Ethereum account through personalSign?

It's personal_sign now, not eth_personalSign. It has always been personal_sign, it's probably just a typo in the Metamask docs. const message = "Hello from Ethereum Stack Exchange!"; const ...
q9f's user avatar
  • 33k
4 votes
Accepted

Is there a way to know the REAL msg.sender?

On a real blockchain, you can't send from whatever account you want. You can only send as an address for which you know the private key. So "the real msg.sender" is just msg.sender. It cannot be ...
user19510's user avatar
  • 28.1k
4 votes

What are the best practices to allow user signup and login for a dapp?

Addressing #4, it's definitely possible, but you will have to make a decision between completely centralized vs decentralized approach. MetaMask is decentralized (end users hold the private keys), ...
Evan H.'s user avatar
  • 171
4 votes
Accepted

Authentication using ethereum account

Despite Metamask seems to complicate the process to you, if you give it a try you'll find that in reality it simplifies it for both users ( until some point ) and developpers. To introduce a bit the ...
Asone's user avatar
  • 839
4 votes

Is it possible to create an X.509 certificate from an Ethereum/Bitcoin private key?

It is possible to create certificates with secp256k1 keys using OpenSSL, for example following OpenSSL generate different types of self signed certificate. The main problem is certificates with ...
Ismael's user avatar
  • 30.5k
3 votes
Accepted

How to use recovery mnemonic in metamask to import account instead of private key?

Importing a mnemonic can only be done when you are not logged in. It's best to backup any existing accounts in the current MetaMask instance before importing a mnemonic. When logged out, you can ...
Henk's user avatar
  • 4,281
3 votes
Accepted

Authentication or Identification of smart contract

You can keep mapping (address => bool) authorizedContracts; inside contract1. And the method addAuthorizedContract should be open only to the owner of contract1. If you want to avoid calling ...
medvedev1088's user avatar
3 votes
Accepted

RPC authentication in Ethereum?

The JSON-RPC interface will talk to anyone who is able to communicate with it over the network. The alternative, IPC, uses a UNIX socket, and will talk to anyone who can access that socket. If you ...
Edmund Edgar's user avatar
  • 16.9k
3 votes

What are the best practices to allow user signup and login for a dapp?

I know its too old thread but since I faced the very same problem I would like to answer it. The concept of digital signature which blockchain uses, is very known tech but unfortunately it is not ...
Vishwas Bhushan's user avatar
3 votes
Accepted

User Whitelisting on Smart Contract

Previous user's answer isn't really workable with a possible user list in the millions--you'd be spending billions of gas to add all the users, which is obviously too much. What you want is a Merkle ...
Meriadoc's user avatar
  • 427
2 votes

What are the best practices to allow user signup and login for a dapp?

You can use an Ethereum address as a unique identifier for a user account. You can then require the holder of the private key that maps to that address to sign a message which you can then check. It ...
Thomas Clowes's user avatar
2 votes
Accepted

How to unlock account from another node in same blockchain network?

In the Answer to the question you referenced, the key phrase is without adding your key files there You can unlock any account from any node, but you have to bring the private key with you. The ...
Rob Hitchens's user avatar
  • 55.4k
2 votes
Accepted

How to authenticate a smart contract

I don't think your question is unclear (someone flagged it) but it's pretty far off from the way Ethereum works conceptually. Let's start with the big one. Everything in Ethereum is deterministic, ...
Rob Hitchens's user avatar
  • 55.4k
2 votes

Authentication or Identification of smart contract

You could use extcodesize and extcodecopy to fetch the code for msg.sender. Then you could hash it and compare to a hash of the known good source code. Note that this only works if the goal is to ...
user19510's user avatar
  • 28.1k
2 votes
Accepted

OAuth/BearerTokens in ChainLink

You use an external adapter. The node side has the OAuth information. So you don't add the information into the smart contract itself. You can check out the Twitter External Adapter and see that all ...
Patrick Collins's user avatar
2 votes
Accepted

Private Ethereum Platform development with Authentication System

In Ethereum there is no such thing as super nodes. You can have several differ sync types like. Fast, Full and Full(archived). But they will all be able to donthe same. Also doing this in mainnet ...
bakon's user avatar
  • 36
2 votes

HMAC-x implementation for solidity

Solidity has the primitives you would need for some HMAC functions, namely several hashing functions. As you pointed out, other hashing functions could be implemented, but hashing in the Ethereum VM ...
notlesh's user avatar
  • 146
2 votes
Accepted

Is there really any secure models for authenticating a user with metamask?

The flow presented by Metamask deals with authentication and does not deal with DoS issues or other security matters. It is considered a secure way of authentication, because the wallet uses the ...
Kof's user avatar
  • 2,964
1 vote

How do I retrieve user data once I have incremented count?

Yes, you can create a mapping which connects each address to its id (check the comments): mapping (uint => Users) public users; mapping(address => bool) _isRegistered; mapping(...
Yakitori's user avatar
  • 767
1 vote
Accepted

Wallet as authenticator with WalletConnect

is there a possibility to get a sign at connect() time, so that the user does not need to confirm twice, once for the connect, once for the sign()? Unfortunately, the wallet interaction is limited to ...
Mikko Ohtamaa's user avatar
1 vote

How chainlink guarantees the authenticity and accuracy of the data it returns to the smart contract

The basic request model would never be something you go to production with, for exactly the reason described. This is why you want to work with a decentralized Chainlink network. The same reason that ...
Patrick Collins's user avatar
1 vote

Metamask Wallet Change in Dapp

You can use the eth_accounts JSON-RPC call which returns the list of accounts owned by the client. Metamask API implements it with : const accounts = await ethereum.request({ method: 'eth_accounts' });...
clement's user avatar
  • 4,322
1 vote

EcRecover signed message does not match PublicAddress

// ("\x19Ethereum") != ("\x19" + "Ethereum") var message = Encoding.UTF8.GetBytes("\x19" + "Ethereum Signed Message:\n" + terms.Length + terms);
Gero's user avatar
  • 83
1 vote

ERC20 Anyone can call approve if knows ABI on contract and my address?

You can execute .send({from: 'SomeAccount'}) only after unlocking SomeAccount on the node that you're communicating with via your Web3 instance. On public nodes this is usually not even an option, ...
goodvibration's user avatar
1 vote

How to authenticate a smart contract

Contracts cannot access someone else information on their own. They can call other contracts to acces information but only when someone else instructed them to do so. For example a smart contract ...
Ismael's user avatar
  • 30.5k
1 vote

Authentication or Identification of smart contract

As you said, you can't really have secrets in the contract. Except if some data is encrypted off-the-blockchain and the result sent to the contract. The problem with that approach is the work that ...
Lauri Peltonen's user avatar
1 vote

Is there anything that is equivalent of Hyperledger Fabric's Membership Service Provider in Ethereum?

According to ethereum documentation- Public blockchains: a public blockchain is a blockchain that anyone in the world can read, anyone in the world can send transactions to and expect to ...
Soham Lawar's user avatar
  • 2,567
1 vote

Is there anything that is equivalent of Hyperledger Fabric's Membership Service Provider in Ethereum?

Ethereum is a public and open protocol. As such, any node that follows protocol is welcome to participate. Having said that, there are approaches to addressing this concern. A team may form a ...
Rob Hitchens's user avatar
  • 55.4k

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