Author: enderlocphan@gmail.com

## Foreword

The documents aim to recap my experience in smart contract automated testing besides the manual testing. I also put the issues that I faced during the execution, indeed, solutions are given.

## Connecting with Remix from localhost

For a complex project, you can't just copy paste the single sol file and let it run. To make our life easier, Remix has localhost connection which allows you to interact with your project in your local machine remotely.

This is something I'm used to doing when the project has a large number of inheritant contracts. Obviously, this make our life easier than ever by just downloading the git project and do some commands.

### Steps:

1. Compile your truffle contract if needed with `npm install` (!remember remvove the package-lock.json, if it does have it). Otherwise, the remix wouldn't be able to load all libraries for the contracts that are being called.

2. Go to WorkSpaces on the left panel and choose "Connect to Localhost"

<img src="https://github.com/enderphan94/solidity-pentest/blob/master/images/remix1.png?raw=true">


3. The message box pops up and you just need to read carefully and copy the command shown in the box to connect your localhost

<img src="https://github.com/enderphan94/solidity-pentest/blob/master/images/remix2.png?raw=true" width="65%" height="65%">

https://gist.github.com/c3b05db188b9a66755e4d4ce3373373d

Important:

> path-to-the-shared-folder: needs to be an absolute path

> remix-ide-instance-URL: needs to plain with http or https

eg: 

https://gist.github.com/9f96a2055bd8b42a5f1b9d0ad08251a2

### Issues

#### Issue 1

Somtimes I still got this error from Remix

>Cannot connect to the remixd daemon. 
>Please make sure you have the remixd running in the background.

What I usually do is just switch to a new terminal tab and re-type the remixd command. If needed, you can just uinstall and reinstall the remixd (Close VS-Code to do this, if you have it opened)

https://remix-ide.readthedocs.io/en/latest/remixd.html

#### Issue 2

The same error but another issue.

https://ethereum.stackexchange.com/questions/78637/cant-connect-remix-ide-using-remixd

## Solc version problems

Source: https://github.com/crytic/solc-select

### Issues

You need to just switch the version of solc quickly by a command. The version of solc is kindda painful, depending on the tools and project, you need to use a specific and exact version to compile.. otherwise broke.

During my audit, I've suffered with solc-select installations. I used to install  via the shell command, but now they've upraded to pip3. The thing is that some docker containers do not support pip3, so you would need to install solc-selct into that docker but pip3. Therefore, I'v a copied version of the solc-select installed via shell.

### Installation

Via shell: https://github.com/enderphan94/solc-select-sh-version

Via pip3: https://github.com/crytic/solc-select

### Usage:

Install the version you want

https://gist.github.com/696d12da5415be51a57254b1ee6c3546

And use it
https://gist.github.com/547569aa651845571a457102ec789b8e

Check your solc version again

https://gist.github.com/120af69c1998830f8671709e117991b3

## Tools

### 1. Slither

Source: https://github.com/crytic/slither

#### Features

* Detects vulnerable Solidity code with low false positives (see the list of [trophies](./trophies.md))
* Identifies where the error condition occurs in the source code
* Easily integrates into continuous integration and Truffle builds
* Built-in 'printers' quickly report crucial contract information
* Detector API to write custom analyses in Python
* Ability to analyze contracts written with Solidity >= 0.4
* Intermediate representation ([SlithIR](https://github.com/trailofbits/slither/wiki/SlithIR)) enables simple, high-precision analyses
* Correctly parses 99.9% of all public Solidity code
* Average execution time of less than 1 second per contract

#### How to install

Slither requires Python 3.6+ and [solc](https://github.com/ethereum/solidity/), the Solidity compiler.

##### Using Pip

https://gist.github.com/ca96530fac9dcad5baaa70227b511054

##### Using Git

https://gist.github.com/bddc7c1dc5a9ba582f7502f560637110

We recommend using an Python virtual environment, as detailed in the [Developer Installation Instructions](https://github.com/trailofbits/slither/wiki/Developer-installation), if you prefer to install Slither via git.

##### Using Docker

Use the [`eth-security-toolbox`](https://github.com/trailofbits/eth-security-toolbox/) docker image. It includes all of our security tools and every major version of Solidity in a single image. `/home/share` will be mounted to `/share`  in the container.

https://gist.github.com/8b5f565e06dfa6f5c17d321da40dbe14

To share a directory in the container:

https://gist.github.com/5f21b0731dbf09306b2754339f2965d9

#### Usage

https://gist.github.com/d97152ab261190f1e44ee80a202ce153

#### Isssue

> Error: Source "@openzeppelin/contracts/utils/Context.sol" not found: File outside of allowed directories.

Fixed: the `--allow-path` does not work, just download the library and copy them into the dir.. casual way :/


### 2. Mythril

Mythril detects a range of security issues, including integer underflows, owner-overwrite-to-Ether-withdrawal, and others. Note that Mythril is targeted at finding common vulnerabilities, and is not able to discover issues in the business logic of an application. Furthermore, Mythril and symbolic executors are generally unsound, as they are often unable to explore all possible states of a program.

Source: https://github.com/ConsenSys/mythril

#### How to install

https://gist.github.com/4a5684bca1e92032944e4b756008fa0d

Install from Pypi:

https://gist.github.com/4a6e66fd5b7309bae36990735374a0da

Note: In my exprience, I prefer using mythril version installed via pip3 rather than Docker. I've faced so many issues with the docker version, and I decided to switch to pip3 one.

#### Usage

Via pip3: https://github.com/ConsenSys/mythril/blob/develop/README.md#usage

Via Docker: ```docker run -v $(pwd):/tmp mythril/myth a /tmp/<file-name>.sol --solv 0.5.0```

#### Issues

##### Issue 1
In case the tool gives you this error:

> mythril.mythril.mythril_disassembler [ERROR]: The file Token.sol does not contain a compilable contract.
> mythril.interfaces.cli [ERROR]: input files do not contain any valid contracts

We can use contract address in testnet or ganache
https://mythril-classic.readthedocs.io/en/master/security-analysis.html

Ganache: ```myth a --rpc ganache -a <address>```

##### Issue 2

Evn: MacOS

Just in case the command ```Pip3 install mythril``` does not work. I don't remember what happened exactly but something does not work with pip3 in MacOS :)

Use the following command 

https://gist.github.com/d91297767da438e24fc1d591fceb3f97

##### Issue 3

Error

>in self.solidity_files[file_index].full_contract_src_maps
>IndexError: list index out of range

Just uninstall mythril and reinstall it

https://gist.github.com/c63618ba096f14fd693494cd5c96b0a6

https://gist.github.com/84611769906dac0a6b776c3e0b85d9b6

### 3. Manticore

This tool takes quite a long time to complete.

#### Features

Program Exploration: Manticore can execute a program with symbolic inputs and explore all the possible states it can reach

Input Generation: Manticore can automatically produce concrete inputs that result in a given program state

Error Discovery: Manticore can detect crashes and other failure cases in binaries and smart contracts

Instrumentation: Manticore provides fine-grained control of state exploration via event callbacks and instruction hooks

Programmatic Interface: Manticore exposes programmatic access to its analysis engine via a Python API

#### Installation

> Note: We recommend installing Manticore in a [virtual environment](https://packaging.python.org/guides/installing-using-pip-and-virtual-environments/#installing-virtualenv)
 to prevent conflicts with other projects or packages

Option 1: Installing from PyPI:

https://gist.github.com/96b26e5a4c29860ed640aa6af1871539

Option 2: Installing from PyPI, with extra dependencies needed to execute native binaries:

https://gist.github.com/dba0c698c9d0fec64d8b85750c0ad8c9

Option 3: Installing a nightly development build:

https://gist.github.com/d6af94952324b92df939340e0fdd02f9

Option 4: Installing from the `master` branch:

https://gist.github.com/cf8aa6adc473670fba5313f47972bbe0

Option 5: Install via Docker:

https://gist.github.com/0f5e3f676cfac90efded606bf14cf339

Once installed, the `manticore` CLI tool and Python API will be available.

For a development installation, see our [wiki](https://github.com/trailofbits/manticore/wiki/Hacking-on-Manticore).

#### Usage

Sigle contract in a file

https://gist.github.com/4bc7805b4af2a8b3a61f700da48b3637

Mutiple contracts in a file

https://gist.github.com/4fe57243add065e61503678ab1284b84

Note:

Manticore takes quite a long time to complete the scan by default, so usually I also use `--quick-mode` option for quick exploration. Disable gas, generate testcase only for alive states, do not explore constant functions. Disable all detectors.

https://gist.github.com/1ada83441fcb622f8c753ae1b43ae657

### 4. Theo

Source: https://github.com/cleanunicorn/theo

#### Features

* Automatic smart contract scanning which generates a list of possible exploits.
* Sending transactions to exploit a smart contract.
* Transaction pool monitor.
* Web3 console
* Frontrunning and backrunning transactions.
* Waiting for a list of transactions and sending out others.
* Estimating gas for transactions means only successful transactions are sent.
* Disabling gas estimation will send transactions with a fixed gas quantity.

#### Installation

https://gist.github.com/70bbab222da3078c9f85242019045249

#### Usage

Usually I deploy the smart contract in Ganache local network, from that, I can freely have the private keys of many accounts. If you have metamask installed, you can deploy in the testnet and get the private key of the accounts.

1. Deploy the contract
2. Run
https://gist.github.com/4019e1d4b2f79f82591fec16d7da1234

3. Enter the private key of the attack's account
4. Enter the smart contract address

eg:

https://gist.github.com/0e69687ce469371f2fdc2eb765abddae

### 5. SmartCheck

Souce: https://www.npmjs.com/package/@smartdec/smartcheck

SmartCheck is an extensible static analysis tool for discovering vulnerabilities and other code issues in Ethereum smart contracts written in the Solidity programming language

#### Installation

https://gist.github.com/b05350d0092b2b00c47e0d5b996b8efc

#### Usage

1. Copy the contract to a folder
2. Run
https://gist.github.com/89205f8e8cab67be2b72cc0649f0a805

### 6. Securitfy2

Source: https://github.com/eth-sri/securify2

#### Furture

* Supports 38 vulnerabilities (see table below)
* Implements novel context-sensitive static analysis written in Datalog
* Analyzes contracts written in Solidity >= 0.5.8

#### Installation

To build the container:

https://gist.github.com/4321d9591c50f24b3653f08ff58f8c53

To run the container:

https://gist.github.com/68cb25b2379807f0e9cc05e912b2f456

contract-dir-full-path: should be the absolute path

eg:

https://gist.github.com/8d417ab0a7877a35f4057b5b0388b9a6

### 7. Sohint

Source: https://github.com/duaraghav8/Ethlint

Ethlint (Formerly Solium) analyzes your Solidity code for style & security issues and fixes them.

#### Installation

https://gist.github.com/50c66eceda258833b699295ff2a088cd

#### Usage

In the root directory of your DApp:
https://gist.github.com/a7e023f090f8acadd5409a9a40487ecb

This creates .soliumrc.json file, which contains configuration that tells Solium how to lint your project. You should modify this file to configure rules, plugins and sharable configs.

I just usually use this simple setting.

https://gist.github.com/bd312d3efa2081b35277b74a7288edf5

Then you can run

https://gist.github.com/edf105c95ca829cb0f03abd8f6d1cfa4

or

https://gist.github.com/4a32858df4a75a3d7396ee9b43a6aa3a

### 8. Spell check

Source: https://github.com/streetsidesoftware/cspell

The cspell mono-repo, a spell checker for code.

#### Installation

https://gist.github.com/b376bd58f2724c70a963ad4055e232b9

#### Usage

https://gist.github.com/03896c4bb6dd551214dba7c6d795dc65

### 9. Sūrya (flow graph)

Source: https://github.com/ConsenSys/surya

Surya is an utility tool for smart contract systems. It provides a number of visual outputs and information about the contracts' structure. Also supports querying the function call graph in multiple ways to aid in the manual inspection of contracts.

#### Installation

Install graphviz

https://gist.github.com/893ab3560b223c97781f1bc1b306c51e

Install surya
https://gist.github.com/7813b4d5283359337da918073bb62883

#### Usage

https://gist.github.com/157f12bb9c8f97938e59e55c2b75e44d

Note: I recommend using Surya in VS Code

## Audit with Visual Studio Code

Here is my list:

1. Name: vscode-slither
> VS Marketplace Link: https://marketplace.visualstudio.com/items?itemName=samparsky.vscode-slither

2. Name: Solidity Visual Developer
>VS Marketplace Link: https://marketplace.visualstudio.com/items?itemName=tintinweb.solidity-visual-auditor

3. Name: Slither
>VS Marketplace Link: https://marketplace.visualstudio.com/items?itemName=trailofbits.slither-vscode

4. Name: Code Spell Checker
>VS Marketplace Link: https://marketplace.visualstudio.com/items?itemName=streetsidesoftware.code-spell-checker

5. Name: mythril
> VS Marketplace Link: https://marketplace.visualstudio.com/items?itemName=xgwang.mythril

6. Name: solidity
>VS Marketplace Link: https://marketplace.visualstudio.com/items?itemName=JuanBlanco.solidity