DEV Community: dongri

Hey

dongri — Fri, 21 Aug 2020 14:51:36 +0000

Hey! is alive?

solidityとweb3のkeccak256について

dongri — Wed, 10 Jun 2020 09:54:38 +0000

Solidity側で以下のようにsha3

byte32 solidityMessage = keccak256(abi.encodePacked(address, msg.value, stringKey));

Web3では以下のように作成

const web3Message = Web3.utils.soliditySha3({t: 'address', v: address}, {t: 'uint', v: '123456'}, {t: 'string', v:'secret-key'});

検証

solidityMessage == web3Message

cryptotako.com

dongri — Sun, 31 May 2020 01:49:07 +0000

I developed a service called cryptotako.com in a private project.

You can transfer ETH through the system without asking for the other party's Ethereum address.

The main features of the service are as follows

Log in with your social network accounts such as Twitter, GitHub, etc.
Log in from your MetaMask, Dapper or other wallet
Select Twitter, GitHub or ETH Address to send ETH
Notifications on Twitter, GitHub
Transaction history
Twitter and GitHub account integration to generate addresses
Private Key Export
Change email, username
Conversion in USD, JPY, the Fiat.

Get real ip of Fastify

dongri — Fri, 29 May 2020 13:15:18 +0000

const app = fastify({
  trustProxy: true,
});

location / {
    proxy_pass http://cryptotako/;
    proxy_set_header X-Forwarded-for $remote_addr;
}

python3 yum

dongri — Fri, 29 May 2020 08:33:59 +0000

  File "/bin/yum", line 30
    except KeyboardInterrupt, e:
                            ^
SyntaxError: invalid syntax

$ sudo vim /bin/yum
#!/usr/bin/python -> #!/usr/bin/python2

  File "/usr/libexec/urlgrabber-ext-down", line 28
    except OSError, e:
                  ^
SyntaxError: invalid syntax

$ sudo vim /usr/libexec/urlgrabber-ext-down
#!/usr/bin/python -> #!/usr/bin/python2

🍺 飲んでdenoいじってみた

dongri — Fri, 15 May 2020 13:24:08 +0000

nodejsの代わりになるのか？！deno(ディーノ)

$ brew install deno
$ deno -V
deno 1.0.0

Welcome

$ deno run https://deno.land/std/examples/welcome.ts
Welcome to Deno 🦕

url先見てみると console.log("Welcome to Deno 🦕");

Web server

$ vim server.ts

import { serve } from "https://deno.land/std@0.50.0/http/server.ts";
const s = serve({ port: 8000 });
console.log("http://localhost:8000/");
for await (const req of s) {
  req.respond({ body: "Hello World\n" });
}

$ deno run --allow-net server.ts
http://localhost:8000/

go modでプライベートgithub参照の時

dongri — Fri, 24 Apr 2020 05:12:30 +0000

こんなエラー出たら

go: finding module for package github.com/***/***
go: downloading github.com/***/*** v0.0.0-20200424032624-7ee614f6e303
github.com/***/*** imports
        github.com/***/***/***: github.com/***/***@v0.0.0-20200424032624-7ee614f6e303: verifying module: github.com/***/***@v0.0.0-20200424032624-7ee614f6e303: reading https://sum.golang.org/lookup/github.com/***/***@v0.0.0-20200424032624-7ee614f6e303: 410 Gone
        server response:
        not found: github.com/***/***@v0.0.0-20200424032624-7ee614f6e303: invalid version: git fetch -f origin refs/heads/*:refs/heads/* refs/tags/*:refs/tags/* in /tmp/gopath/pkg/mod/cache/vcs/2d253e2ea6ebdb2e3be78af07d3b07b09c565cb0a0efc6a1ac5deb8f6aeca582: exit status 128:
                fatal: could not read Username for 'https://github.com': terminal prompts disabled

以下のように設定

$ vim ~/.gitconfig
[url "git@github.com:"]
    insteadOf = https://github.com/

$ vim ~/.bashrc
export GO111MODULE=on # Go Mobules
export GOSUMDB=off
export GOPROXY=direct

geth syncmode

dongri — Fri, 10 Apr 2020 09:09:42 +0000

Full

$ geth --syncmode full

- BlockHaeder
- BlockBody
  - Transactions[]
  - Uncles[]
- Receipt
- State

700GB

Fast (default)

$ geth --syncmode fast

- BlockHaeder
- BlockBody
  - Transactions[]
  - Uncles[]
- Receipt

150GB

Light

$ geth --syncmode light

- BlockHeader

ERC

dongri — Sun, 05 Apr 2020 08:25:43 +0000

ERC: Ethereum Request for Comments

ERC200
https://en.bitcoinwiki.org/wiki/ERC20

ERC721
http://erc721.org/

Ethereum Wallet Sample code

dongri — Wed, 01 Apr 2020 15:35:05 +0000

var Wallet = require('ethereumjs-wallet');
let hdkey = require('ethereumjs-wallet/hdkey');
var EthUtil = require('ethereumjs-util');
let bip39 = require("bip39");

// input secret
const privateKeyBuffer = EthUtil.toBuffer('0xb3daa3c32f6f6c71a3fc0c3af081e971c78706459f358b43451a1ba0d4ef3dba');
const wallet = Wallet.fromPrivateKey(privateKeyBuffer);

// public key from secret key
const publicKey = wallet.getPublicKeyString();                                                                                                                                                                                                                                                               
console.log('public key: ' + publicKey);

// address from secret key
const address = wallet.getAddressString()
console.log('addres   : ' + address);

const mnemonic = "soldier clump basket brain suit wire whisper equip aim neck kangaroo rely";

// hd wallet from mnemonic
let hdwallet = hdkey.fromMasterSeed(bip39.mnemonicToSeedSync(mnemonic));

// master key
console.log('master private key: ' + hdwallet.privateExtendedKey())
let wallet_hdpath = "m/44'/60'/0'/0/";

// generate wallets
for (let i = 0; i < 5; i++) {
  let wallet = hdwallet.derivePath(wallet_hdpath + i).getWallet();
  let address = wallet.getAddressString();
  console.log('address-' + i + ': ' + address);
}

public key: 0x12dd7df75e3a2b2b2d17358221f0811a6a19251c66cf502a6ca02a23205f3d27b7c416eca8e9e7ae45e47862ff7bf0ccc013f27a81e4fc9a0d513808db28d90b
addres   : 0x72a60325bbcff70e6278f03482b7ae44d175503b
master private key: xprv9s21ZrQH143K3oPizmavifFSRXSdVFTxVn3zdWqa3X2AqAidQnef4sxPVLsFM9PtZcASh14fr3e1Fwac7qdvKyqQgdg8tCKTDQ4LLgkvLmh
address-0: 0x72a60325bbcff70e6278f03482b7ae44d175503b
address-1: 0x2bd38b66259092248e9a1943acd63dffda479010
address-2: 0x48a0806dc7c143f4e31a68dd5590cb57b1b89cda
address-3: 0x54072de9b7c7d29dbf189fb0ed4670d53975a6a6
address-4: 0xf6b82083948be7ce8e36699a00041ddc1be2354d

Command CompileSwift failed with a nonzero exit code

dongri — Mon, 30 Mar 2020 10:34:08 +0000

Shift + Command + K
&
Option + Shift + Command + K

Cloudflare & IPFS

dongri — Sun, 29 Mar 2020 07:21:56 +0000

$ dig +noall +answer TXT _dnslink.dongri.org
_dnslink.dongri.org.    299     IN      TXT     "dnslink=/ipfs/QmRQV16f9YMExNs3p8562xGHqQkWXe4CFPrVuGp9CGmFq9"