93 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
			
		
		
	
	
			93 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
| # go-fuzz-headers
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| This repository contains various helper functions for go fuzzing. It is mostly used in combination with [go-fuzz](https://github.com/dvyukov/go-fuzz), but compatibility with fuzzing in the standard library will also be supported. Any coverage guided fuzzing engine that provides an array or slice of bytes can be used with go-fuzz-headers.
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| 
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| 
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| ## Usage
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| Using go-fuzz-headers is easy. First create a new consumer with the bytes provided by the fuzzing engine:
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| 
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| ```go
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| import (
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| 	fuzz "github.com/AdaLogics/go-fuzz-headers"
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| )
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| data := []byte{'R', 'a', 'n', 'd', 'o', 'm'}
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| f := fuzz.NewConsumer(data)
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| 
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| ```
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| 
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| This creates a `Consumer` that consumes the bytes of the input as it uses them to fuzz different types.
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| 
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| After that, `f` can be used to easily create fuzzed instances of different types. Below are some examples:
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| 
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| ### Structs
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| One of the most useful features of go-fuzz-headers is its ability to fill structs with the data provided by the fuzzing engine. This is done with a single line:
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| ```go
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| type Person struct {
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|     Name string
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|     Age  int
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| }
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| p := Person{}
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| // Fill p with values based on the data provided by the fuzzing engine:
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| err := f.GenerateStruct(&p)
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| ```
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| 
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| This includes nested structs too. In this example, the fuzz Consumer will also insert values in `p.BestFriend`:
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| ```go
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| type PersonI struct {
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|     Name       string
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|     Age        int
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|     BestFriend PersonII
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| }
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| type PersonII struct {
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|     Name string
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|     Age  int
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| }
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| p := PersonI{}
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| err := f.GenerateStruct(&p)
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| ```
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| 
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| If the consumer should insert values for unexported fields as well as exported, this can be enabled with:
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| 
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| ```go
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| f.AllowUnexportedFields()
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| ```
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| 
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| ...and disabled with:
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| 
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| ```go
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| f.DisallowUnexportedFields()
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| ```
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| 
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| ### Other types:
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| 
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| Other useful APIs:
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| 
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| ```go
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| createdString, err := f.GetString() // Gets a string
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| createdInt, err := f.GetInt() // Gets an integer
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| createdByte, err := f.GetByte() // Gets a byte
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| createdBytes, err := f.GetBytes() // Gets a byte slice
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| createdBool, err := f.GetBool() // Gets a boolean
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| err := f.FuzzMap(target_map) // Fills a map
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| createdTarBytes, err := f.TarBytes() // Gets bytes of a valid tar archive
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| err := f.CreateFiles(inThisDir) // Fills inThisDir with files
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| createdString, err := f.GetStringFrom("anyCharInThisString", ofThisLength) // Gets a string that consists of chars from "anyCharInThisString" and has the exact length "ofThisLength"
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| ```
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| 
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| Most APIs are added as they are needed.
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| 
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| ## Projects that use go-fuzz-headers
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| - [runC](https://github.com/opencontainers/runc)
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| - [Istio](https://github.com/istio/istio)
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| - [Vitess](https://github.com/vitessio/vitess)
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| - [Containerd](https://github.com/containerd/containerd)
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| 
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| Feel free to add your own project to the list, if you use go-fuzz-headers to fuzz it.
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| 
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| 
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|  
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| 
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| ## Status
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| The project is under development and will be updated regularly.
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| 
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| ## References
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| go-fuzz-headers' approach to fuzzing structs is strongly inspired by [gofuzz](https://github.com/google/gofuzz). | 
