# Slither, the Solidity source analyzer [![Build Status](https://travis-ci.com/trailofbits/slither.svg?token=JEF97dFy1QsDCfQ2Wusd&branch=master)](https://travis-ci.com/trailofbits/slither) [![Slack Status](https://empireslacking.herokuapp.com/badge.svg)](https://empireslacking.herokuapp.com) [![PyPI version](https://badge.fury.io/py/slither-analyzer.svg)](https://badge.fury.io/py/slither-analyzer) Slither is a Solidity static analysis framework written in Python 3. It runs a suite of vulnerability detectors, prints visual information about contract details, and provides an API to easily write custom analyses. Slither enables developers to find vulnerabilities, enhance their code comphrehension, and quickly prototype custom analyses. ## Features * Detects vulnerable Solidity code with low false positives * Identifies where the error condition occurs in the source code * Easy integration 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 ## Usage Run Slither on a Truffle application: ``` slither . ``` Run Slither on a single file: ``` $ slither tests/uninitialized.sol [..] INFO:Detectors: Uninitialized.destination (tests/uninitialized.sol#5) is never initialized. It is used in: - transfer (tests/uninitialized.sol#7-9) Reference: https://github.com/trailofbits/slither/wiki/Vulnerabilities-Description#uninitialized-state-variables [..] ``` Slither can be run on: - A `.sol` file - A Truffle directory - A directory containing `*.sol` files (all the `*.sol` files will be analyzed) - A glob (be sure to quote the argument when using a glob) ### Configuration * `--solc SOLC`: Path to `solc` (default 'solc') * `--solc-args SOLC_ARGS`: Add custom solc arguments. `SOLC_ARGS` can contain multiple arguments * `--disable-solc-warnings`: Do not print solc warnings * `--solc-ast`: Use the solc AST file as input (`solc file.sol --ast-json > file.ast.json`) * `--json FILE`: Export results as JSON ## Detectors By default, all the detectors are run. Num | Detector | What it Detects | Impact | Confidence --- | --- | --- | --- | --- 1 | `shadowing-state` | [State variables shadowing](https://github.com/trailofbits/slither/wiki/Vulnerabilities-Description#state-variable-shadowing) | High | High 2 | `suicidal` | [Functions allowing anyone to destruct the contract](https://github.com/trailofbits/slither/wiki/Vulnerabilities-Description#suicidal) | High | High 3 | `uninitialized-state` | [Uninitialized state variables](https://github.com/trailofbits/slither/wiki/Vulnerabilities-Description#uninitialized-state-variables) | High | High 4 | `uninitialized-storage` | [Uninitialized storage variables](https://github.com/trailofbits/slither/wiki/Vulnerabilities-Description#uninitialized-storage-variables) | High | High 5 | `arbitrary-send` | [Functions that send ether to arbitrary destinations](https://github.com/trailofbits/slither/wiki/Vulnerabilities-Description#functions-that-send-ether-to-arbitrary-destinations) | High | Medium 6 | `controlled-delegatecall` | [Controlled delegatecall destination](https://github.com/trailofbits/slither/wiki/Vulnerabilities-Description#controlled-delegatecall) | High | Medium 7 | `reentrancy-eth` | [Reentrancy vulnerabilities (theft of ethers)](https://github.com/trailofbits/slither/wiki/Vulnerabilities-Description#reentrancy-vulnerabilities) | High | Medium 8 | `incorrect-equality` | [Dangerous strict equalities](https://github.com/trailofbits/slither/wiki/Vulnerabilities-Description#dangerous-strict-equalities) | Medium | High 9 | `locked-ether` | [Contracts that lock ether](https://github.com/trailofbits/slither/wiki/Vulnerabilities-Description#contracts-that-lock-ether) | Medium | High 10 | `shadowing-abstract` | [State variables shadowing from abstract contracts](https://github.com/trailofbits/slither/wiki/Vulnerabilities-Description#state-variable-shadowing-from-abstract-contracts) | Medium | High 11 | `constant-function` | [Constant functions changing the state](https://github.com/trailofbits/slither/wiki/Vulnerabilities-Description#constant-functions-changing-the-state) | Medium | Medium 12 | `reentrancy-no-eth` | [Reentrancy vulnerabilities (no theft of ethers)](https://github.com/trailofbits/slither/wiki/Vulnerabilities-Description#reentrancy-vulnerabilities-1) | Medium | Medium 13 | `tx-origin` | [Dangerous usage of `tx.origin`](https://github.com/trailofbits/slither/wiki/Vulnerabilities-Description#dangerous-usage-of-txorigin) | Medium | Medium 14 | `uninitialized-local` | [Uninitialized local variables](https://github.com/trailofbits/slither/wiki/Vulnerabilities-Description#uninitialized-local-variables) | Medium | Medium 15 | `unused-return` | [Unused return values](https://github.com/trailofbits/slither/wiki/Vulnerabilities-Description#unused-return) | Medium | Medium 16 | `shadowing-builtin` | [Built-in symbol shadowing](https://github.com/trailofbits/slither/wiki/Vulnerabilities-Description#builtin-symbol-shadowing) | Low | High 17 | `shadowing-local` | [Local variables shadowing](https://github.com/trailofbits/slither/wiki/Vulnerabilities-Description#local-variable-shadowing) | Low | High 18 | `calls-loop` | [Multiple calls in a loop](https://github.com/trailofbits/slither/wiki/Vulnerabilities-Description/_edit#calls-inside-a-loop) | Low | Medium 19 | `reentrancy-benign` | [Benign reentrancy vulnerabilities](https://github.com/trailofbits/slither/wiki/Vulnerabilities-Description#reentrancy-vulnerabilities-2) | Low | Medium 20 | `timestamp` | [Dangerous usage of `block.timestamp`](https://github.com/trailofbits/slither/wiki/Vulnerabilities-Description#block-timestamp) | Low | Medium 21 | `assembly` | [Assembly usage](https://github.com/trailofbits/slither/wiki/Vulnerabilities-Description#assembly-usage) | Informational | High 22 | `constable-states` | [State variables that could be declared constant](https://github.com/trailofbits/slither/wiki/Vulnerabilities-Description#state-variables-that-could-be-declared-constant) | Informational | High 23 | `external-function` | [Public function that could be declared as external](https://github.com/trailofbits/slither/wiki/Vulnerabilities-Description#public-function-that-could-be-declared-as-external) | Informational | High 24 | `low-level-calls` | [Low level calls](https://github.com/trailofbits/slither/wiki/Vulnerabilities-Description#low-level-calls) | Informational | High 25 | `naming-convention` | [Conformance to Solidity naming conventions](https://github.com/trailofbits/slither/wiki/Vulnerabilities-Description#conformance-to-solidity-naming-conventions) | Informational | High 26 | `pragma` | [If different pragma directives are used](https://github.com/trailofbits/slither/wiki/Vulnerabilities-Description#different-pragma-directives-are-used) | Informational | High 27 | `solc-version` | [Incorrect Solidity version (< 0.4.24 or complex pragma)](https://github.com/trailofbits/slither/wiki/Vulnerabilities-Description#incorrect-version-of-solidity) | Informational | High 28 | `unused-state` | [Unused state variables](https://github.com/trailofbits/slither/wiki/Vulnerabilities-Description#unused-state-variables) | Informational | High [Contact us](https://www.trailofbits.com/contact/) to get access to additional detectors. ### Printers To run a printer, use `--print` and a comma-separated list of printers. Num | Printer | Description --- | --- | --- 1 | `call-graph` | Export the call-graph of the contracts to a dot file 2 | `cfg` | Export the CFG of each functions 3 | `contract-summary` | Print a summary of the contracts 4 | `function-summary` | Print a summary of the functions 5 | `human-summary` | Print a human readable summary of the contracts 6 | `inheritance` | Print the inheritance relations between contracts 7 | `inheritance-graph` | Export the inheritance graph of each contract to a dot file 8 | `slithir` | Print the slithIR representation of the functions 9 | `slithir-ssa` | Print the slithIR representation of the functions 10 | `vars-and-auth` | Print the state variables written and the authorization of the functions ## How to install Slither requires Python 3.6+ and [solc](https://github.com/ethereum/solidity/), the Solidity compiler. ### Using Pip ``` $ pip install slither-analyzer ``` ### Using Git ```bash $ git clone https://github.com/trailofbits/slither.git && cd slither $ python setup.py install ``` We recommend to use a Python virtual environment to install slither from git (see the [Developer Installation Instructions](https://github.com/trailofbits/slither/wiki/Developer-installation)) ### Using Docker We recommend to use [`eth-security-toolbox`](https://github.com/trailofbits/eth-security-toolbox/): ``` docker pull trailofbits/eth-security-toolbox ``` To share a directory in the container: ``` docker run -it -v /home/share:/share trailofbits/eth-security-toolbox ``` `/home/share` will be mounted to `/share` in the container. You can switch the solc version using [`solc-select`](https://github.com/trailofbits/eth-security-toolbox/#usage). ## Getting Help Feel free to stop by our [Slack channel](https://empireslacking.herokuapp.com) (#ethereum) for help using or extending Slither. * The [Printer documentation](https://github.com/trailofbits/slither/wiki/Printer-documentation) describes the information Slither is capable of visualizing for each contract. * The [Detector documentation](https://github.com/trailofbits/slither/wiki/Adding-a-new-detector) describes how to write a new vulnerability analyses. * The [API documentation](https://github.com/trailofbits/slither/wiki/API-examples) describes the methods and objects available for custom analyses. * The [SlithIR documentation](https://github.com/trailofbits/slither/wiki/SlithIR) describes the SlithIR intermediate representation. ## License Slither is licensed and distributed under the AGPLv3 license. [Contact us](mailto:opensource@trailofbits.com) if you're looking for an exception to the terms.