File Upload Module

Secure file upload handler with magic bytes validation and path traversal prevention.

What's Included

• Secure file upload handling
• Magic bytes validation (not just extension)
• Path traversal prevention
• File size limits
• Rate limiting
• Storage abstraction

Quick Copy

cp -r registry/file-upload/src/go/* yourproject/internal/fileupload/

Usage

Basic Upload

handler := fileupload.NewHandler(fileupload.Config{
    MaxFileSize: 10 << 20, // 10 MB
    AllowedTypes: []string{"image/jpeg", "image/png", "application/pdf"},
    UploadDir: "./uploads",
})

http.Handle("/upload", handler)

Custom Storage

type S3Storage struct {
    // ...
}

func (s *S3Storage) Save(ctx context.Context, name string, reader io.Reader) error {
    // Upload to S3
}

handler := fileupload.NewHandler(fileupload.Config{
    Storage: &S3Storage{},
})

Rate Limiting

handler := fileupload.NewHandler(fileupload.Config{
    RateLimiter: ratelimit.NewFixedWindow(10, time.Minute),
})

Configuration

Parameter	Description	Default
MaxFileSize	Maximum file size in bytes	10 MB
AllowedTypes	Allowed MIME types	All
UploadDir	Local storage directory	./uploads
Storage	Custom storage backend	Local
RateLimiter	Rate limiter instance	None

File Reference

File	Purpose
handler.go	HTTP upload handler
config.go	Configuration
validate.go	File validation
storage.go	Local storage implementation

Security Features

• Magic bytes validation (not just extension check)
• Path traversal prevention with filepath.Base()
• File size limit prevents large payload attacks
• Rate limiting prevents abuse

Tests

cd registry/file-upload/src/go
go test -v ./...