safeinput

README

go-safeinput

Universal input sanitization for Go applications - MITRE CWE Top 25 coverage.

Badge	Status
CI
Go Report
Coverage
Docs
License	MIT

Features

• CWE-79: Cross-site Scripting (XSS) prevention
• CWE-89: SQL Injection prevention
• CWE-22: Path Traversal prevention
• CWE-78: OS Command Injection prevention
• Zero external dependencies - uses only Go standard library
• Greater than 90% test coverage
• Docker support with multi-stage builds
• Security scanning with gosec, govulncheck, CodeQL

Requirements

• Go 1.24 or higher
• Docker (optional)

Installation

go get github.com/ravisastryk/go-safeinput

Quick Start

package main

import (
    "fmt"
    "github.com/ravisastryk/go-safeinput"
)

func main() {
    s := safeinput.Default()
    
    // XSS Prevention
    safe, _ := s.Sanitize("<script>alert('xss')</script>Hi", safeinput.HTMLBody)
    fmt.Println(safe) // Output: Hi
    
    // Path Traversal Prevention
    _, err := s.Sanitize("../../etc/passwd", safeinput.FilePath)
    fmt.Println(err) // Output: path traversal detected
    
    // SQL Injection Prevention
    _, err = s.Sanitize("users; DROP TABLE--", safeinput.SQLIdentifier)
    fmt.Println(err) // Output: invalid SQL identifier
}

Development

# Run tests
make test

# Run linter
make lint

# Run security checks
make security

# Build Docker image
make docker

License

MIT License - see LICENSE for details.

---

Author: Ravi Sastry Kadali (https://github.com/ravisastryk)

Documentation

Overview

Package safeinput provides context-aware input sanitization for Go applications. It addresses MITRE CWE Top 25 injection vulnerabilities including:

• CWE-79: Cross-site Scripting (XSS)
• CWE-89: SQL Injection
• CWE-22: Path Traversal
• CWE-78: OS Command Injection

Index

• Variables
• func SanitizeShellArg(input string) string
• func StripNullBytes(s string) string
• type Config
• type Context
  • func (c Context) String() string
• type Sanitizer
  • func Default() *Sanitizer
  • func New(cfg Config) *Sanitizer
  • func (s *Sanitizer) GetConfig() Config
  • func (s *Sanitizer) IsValid(input string, ctx Context) bool
  • func (s *Sanitizer) MustSanitize(input string, ctx Context) string
  • func (s *Sanitizer) Sanitize(input string, ctx Context) (string, error)

Variables

var (
	// ErrInputTooLong is returned when input exceeds maximum length.
	ErrInputTooLong   = errors.New("input exceeds maximum length")
	ErrUnknownContext = errors.New("unknown sanitization context")
	ErrNullByte       = errors.New("null byte detected in input")
)

Functions

func SanitizeShellArg

func SanitizeShellArg(input string) string

SanitizeShellArg sanitizes shell command arguments (CWE-78). Only allows alphanumeric characters, dash, underscore, period, and forward slash.

func StripNullBytes

func StripNullBytes(s string) string

StripNullBytes removes null bytes from a string.

Types

type Config

type Config struct {
	MaxInputLength  int
	AllowedHTMLTags []string
	BasePath        string
	StrictMode      bool
	StripNullBytes  bool
}

Config holds sanitizer configuration options.

type Context

type Context int

Context defines the output context for sanitization.

const (
	// HTMLBody sanitizes for HTML body content (CWE-79).
	HTMLBody Context = iota
	// HTMLAttribute sanitizes for HTML attribute values (CWE-79).
	HTMLAttribute
	// SQLIdentifier sanitizes SQL identifiers (CWE-89).
	SQLIdentifier
	// SQLValue validates values before queries (CWE-89).
	SQLValue
	// FilePath sanitizes filesystem paths (CWE-22).
	FilePath
	// URLPath sanitizes URL path components.
	URLPath
	// URLQuery sanitizes URL query parameters.
	URLQuery
	// ShellArg sanitizes shell command arguments (CWE-78).
	ShellArg
)

func (Context) String

func (c Context) String() string

String returns a human-readable name for the context.

type Sanitizer

type Sanitizer struct {
	// contains filtered or unexported fields
}

Sanitizer provides the main sanitization interface.

func Default

func Default() *Sanitizer

Default returns a Sanitizer with secure default settings.

func New

func New(cfg Config) *Sanitizer

New creates a new Sanitizer with the given configuration.

func (*Sanitizer) GetConfig

func (s *Sanitizer) GetConfig() Config

GetConfig returns a copy of the configuration.

func (*Sanitizer) IsValid

func (s *Sanitizer) IsValid(input string, ctx Context) bool

IsValid checks if input is valid for the given context.

func (*Sanitizer) MustSanitize

func (s *Sanitizer) MustSanitize(input string, ctx Context) string

MustSanitize panics on error.

func (*Sanitizer) Sanitize

func (s *Sanitizer) Sanitize(input string, ctx Context) (string, error)

Sanitize processes input for the specified context.