代理合约1. 代理模式 solidity合约部署到链上之后，代码是不可变的。 这一特性存在了一个严重的缺点：就算合约中存在bug，也不能修改或者升级，只能部署新合约。但是新合约的地址和旧合约的地址不一样，而且合约的数据也需要花费大量的gas进行迁移。 为了解决这一问题，从而引入了 代理模式这一概念。 代理模式将合约数据和逻辑分开，分别保存在不同的合约中。以上图为例，数据（状态变量）存储在...

前言：Uniswap V2代码结构 Uniswap智能合约代码由两个github项目组成。一个是core，一个是periphery。 https://github.com/Uniswap/uniswap-v2-core.git https://github.com/Uniswap/uniswap-v2-periphery.git core偏核心逻辑，单个swap的逻辑。periphery偏外...

1. issue A new marketplace of Damn Valuable NFTs has been released! There’s been an initial mint of 6 NFTs, which are available for sale in the marketplace. Each one at 15 ETH. The developers behin...

1. issue The developers of the previous pool seem to have learned the lesson. And released a new version! Now they’re using a Uniswap v2 exchange as a price oracle, along with the recommended utili...

1. issue There’s a lending pool where users can borrow Damn Valuable Tokens (DVTs). To do so, they first need to deposit twice the borrow amount in ETH as collateral. The pool currently has 100000 ...

1. 前言主要是在 靶场 刷题的时候遇到的，题目要求 将一串ASCII码转为字符串，再将字符串解码为一串私钥。感觉很有趣，于是乎，便记录下来。 2. 题目一串已知的ASCII码 14d 48 68 6a 4e 6a 63 34 5a 57 59 78 59 57 45 30 4e 54 5a 6b 59 54 59 31 59 7a 5a 6d 59 7a 55 34 4e 6a 46 6b...

1. issue While poking around a web service of one of the most popular DeFi projects in the space, you get a somewhat strange response from their server. Here’s a snippet: 123456789HTTP/2 200 OKcont...

1. issue A new cool lending pool has launched! It’s now offering flash loans of DVT tokens. It even includes a fancy governance mechanism to control it. What could go wrong, right ? You start with ...

1. issue There’s a pool offering rewards in tokens every 5 days for those who deposit their DVT tokens into it. Alice, Bob, Charlie and David have already deposited some DVT tokens, and have won th...

1. issue A surprisingly simple pool allows anyone to deposit ETH, and withdraw it at any point in time. It has 1000 ETH in balance already, and is offering free flash loans using the deposited ETH ...