nuclei/pkg/utils/utils.go

package utils

import (
	"errors"
	"io"
	"net/url"
	"strings"

	"github.com/projectdiscovery/nuclei/v3/pkg/catalog"
	"github.com/projectdiscovery/nuclei/v3/pkg/catalog/config"
	"github.com/projectdiscovery/nuclei/v3/pkg/utils/yaml"
	"github.com/projectdiscovery/retryablehttp-go"
	fileutil "github.com/projectdiscovery/utils/file"
)

func IsBlank(value string) bool {
	return strings.TrimSpace(value) == ""
}

func UnwrapError(err error) error {
	for { // get the last wrapped error
		unwrapped := errors.Unwrap(err)
		if unwrapped == nil {
			break
		}
		err = unwrapped
	}
	return err
}

// IsURL tests a string to determine if it is a well-structured url or not.
func IsURL(input string) bool {
	u, err := url.Parse(input)
	return err == nil && u.Scheme != "" && u.Host != ""
}

// ReadFromPathOrURL reads and returns the contents of a file or url.
func ReadFromPathOrURL(templatePath string, catalog catalog.Catalog) (data []byte, err error) {
	var reader io.Reader
	if IsURL(templatePath) {
		resp, err := retryablehttp.DefaultClient().Get(templatePath)
		if err != nil {
			return nil, err
		}
		defer resp.Body.Close()
		reader = resp.Body
	} else {
		f, err := catalog.OpenFile(templatePath)
		if err != nil {
			return nil, err
		}
		defer f.Close()
		reader = f
	}

	data, err = io.ReadAll(reader)
	if err != nil {
		return nil, err
	}

	// pre-process directives only for local files
	if fileutil.FileExists(templatePath) && config.GetTemplateFormatFromExt(templatePath) == config.YAML {
		data, err = yaml.PreProcess(data)
		if err != nil {
			return nil, err
		}
	}

	return
}

// StringSliceContains checks if a string slice contains a string.
func StringSliceContains(slice []string, item string) bool {
	for _, i := range slice {
		if strings.EqualFold(i, item) {
			return true
		}
	}
	return false
}