11 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 ...
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  • 2,286
10 votes
Accepted

How can non-javascript applications communicate with Ethereum nodes?

Here are some libraries for interacting with an Ethereum node. They are grouped by language, and roughly according to their last commit, with any appropriate brief notes. Javascript has been ...
6 votes
Accepted

Parity Full History Node

I hope you are running Parity version 1.8.6 because earlier versions wont make it on HDD! Starting at around block 2.4 million are the so called spam blocks, see: Why is my node synchronization ...
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  • 31.5k
6 votes
Accepted

Best possible way to launch the ethereum mainnet node on AWS

Here's what I am using: AWS Instance Setup New EC2 instance Ubuntu Server 16.04 LTS (HVM), SSD Volume Type - ami-10547475 t2.large: 2 vCPUs, 8GB RAM 250 GB (currently about 60gb is being used) nginx ...
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  • 2,286
6 votes
Accepted

Ethereum node hardware requirements

The full blockchain is over 200GB. So long as you have even a relatively modest desktop CPU (or single core of one in a virtualized cloud environment), you should have no difficulty staying in sync, ...
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  • 6,550
6 votes

How to store lots of private keys on a server?

The best way to store the keys will depend on how you need to use them. For example, if you don't need to sign with them in real time, you may want to keep them on a separate system that isn't usually ...
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  • 16.4k
6 votes

Why do blockchain networks like Ethereum utilize JSON RPC calls and not REST APIs or graphQL?

JSON-RPC is not a behaviour of the Ethereum network - Ethereum clients don't talk to each other via JSON-RPC - it's just a notation to encode a remote procedure call that some Ethereum client can ...
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5 votes
Accepted

How do I host Ethereum on a server?

There are several ways you can run Ethereum: PyEthApp Python version GoEthereum Go Version (Probably the most popular) EthereumJ Java version Web3 umbrella C++ version All of the above are developed ...
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  • 6,043
3 votes
Accepted

should I use server side rendering(Next.js) for a dapp?

The big idea behind using the Next.js in ethereum applications (dapps) is server side rendering. You can also use CSR but it will not be good for user experience. Let say you are building an voting ...
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3 votes
Accepted

How to securely Interact with a contract on user's behalf from centralized server?

Pre-Approve The user could sign transactions offline for example using ethereumjs-tx. The service then broadcasts the signed transactions. These could either modify the contract directly or they could ...
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  • 3,282
3 votes

Hosting Ethereum on Digital Ocean

Technically it is pretty possible. On the other hand to keep your money on platform like Digital Ocean doesn`t look as a good practice. Platforms with a strong identity management like AWS, Azure, ...
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  • 221
3 votes

How to sign a transaction in Rust

There is a package for this called ethereum-tx-sign on crates.io. It provides a RawTransaction structure with a sign method. It doesn't have any dependency on web3 and you can sign the transactions ...
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2 votes
Accepted

Server for end production dAPP?

The whole purpose of DApps is that you don't need to setup a back-end for them, since the Blockchain acts as a common back-end shared across all DApps. Most of the time, a simple static HTML/JS/CSS ...
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2 votes
Accepted

How to generate Ethereum wallets & keys on serverside with JS?

Using web3js library, here is how you do it on nodejs serverside //generate private key privateKey = web3.eth.accounts.create().privateKey.substr(2) //generates pubKey from ...
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  • 192
2 votes

Best possible way to launch the ethereum mainnet node on AWS

My configurations and experiences: Ubuntu Server 16.04 LTS (HVM), SSD Volume Type. Absolutely must have 8+ gb of RAM. Don't go any less or you'll run into strange problems. The m5.large works well....
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  • 600
2 votes

How to sign a transaction in Rust

There's a trick using python's web3 package with cpython: let gil = Python::acquire_gil(); let py = gil.python(); let web3 = py.import("web3").unwrap(); let transaction = { let transaction = ...
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2 votes

How to sign a transaction in Rust

It is a function of wallet to store and use your private key. web3 API like rust-web3 usually leave transaction signing to wallet. Therefore your option is to reuse the code in Ethereum wallets that ...
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2 votes
Accepted

How Can I Sign A Transaction Server-Side?

Yes, you absolutely can! You will have to us the EthereumJS-tx package from NPM, you can get more information here: https://github.com/ethereumjs/ethereumjs-tx. It's as simple as: const EthereumTx = ...
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2 votes

If crypto art is stored off-chain, how does the collector have any control over their NFT's contents if the server where it is saved shuts down?

There are several questions here. Let's review. If crypto art is stored off-chain, how does the collector have any control over their NFT's contents if the server where it is saved shuts down? Answer: ...
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2 votes
Accepted

How to make sure that GET call is coming from Oracle and not some other entity?

Your application works as such: Dapp -> Oracle -> Server And you're looking for help from the Oracle -> Server section. This is a general security question and doesn't have anything to do ...
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2 votes
Accepted

How can a server except a signed tx and pay the gas?

Question 1: For your first question, it is possible to sign the transaction at client-side and send it to the provider from your server. You'll have to call the web3.js method sendSignedTransaction to ...
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2 votes

How to use web3.js in node.js web server

I think you're mixing things up. You have to understand which code runs in the frontend (browser) and in the backend (server). window.ethereum is injected by metamask but it's only available in the ...
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  • 436
2 votes

Open Source projects that serve wallets as APIs

I'm working on a CLI wallet https://0xweb.org, also this is a contract package manager for NodeJS. Though this is a side project, which we decided to open source, it is already completely functional. ...
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  • 201
1 vote

How to tell if an NFT jpg is stored on a legitimate IPFS domain?

Along the lines of the "Don't Trust. Verify.™" maxim, you can verify the IPFS hash yourself through a known, trustworthy IPFS gateway. For example, the following URL routes through an IPFS ...
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1 vote

Why do blockchain networks like Ethereum utilize JSON RPC calls and not REST APIs or graphQL?

Your question assumptions are false, because there are other API protocols like graphQL for Ethereum. Why everyone is using JSON-RPC is because Satoshi chose JSON-RPC for Bitcoin back in 2009. Then ...
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1 vote

How Can I Sign A Transaction Server-Side?

You will have to perform three steps to sign in and access any methods from a deployed contract : Create transaction Sign the transaction Broadcast the transaction // library required var Web3 = ...
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1 vote

How to install infura to a server runing ubuntu 16.04

The concept of Infura is to host highly available Ethereum nodes for endusers and offer a remote access to Ethereum (via JSON-RPC). So you don't need to install anything, it's more or less like a ...
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1 vote

DApp on Node2 accessing smart contract deployed by Node1

Deploying a contract on the network by any node in that network makes it accessible by all the nodes in the network. The JSON-RPC error is probably due to the second node (laptop) not being properly ...
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1 vote

How to deploy a smart contract in a server?

To deploy a smart contract on ethereum, you have to make a deployment transaction. A deployment transaction is send contract bytecode to empty address. For example: My add.sol pragma solidity 0.5....
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  • 307
1 vote

For production dApps, what kind of sync should be done on server node?

Fast synchronization is usually OK, you download both blocks and states. However, using full synchronization you only download the blocks, and compute the states yourself. It takes MUCH more time, but ...
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  • 360

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