utils.go

package shadowserver

import (
	"crypto/hmac"
	"crypto/sha256"
	"encoding/hex"
	"encoding/json"
	"fmt"
	"github.com/rs/zerolog"
	"os"
	"strconv"
	"time"
)

const (
	B  = 1
	KB = 1024 * B
	MB = 1024 * KB
	GB = 1024 * MB
)

// ComputeHmac compute HMAC of data
func ComputeHmac(secret string, data []byte) string {
	// create a new HMAC by defining the hash type and the key
	h := hmac.New(sha256.New, []byte(secret))

	// compute the HMAC
	h.Write(data)
	d := h.Sum(nil)

	return hex.EncodeToString(d)
}

// PrintJson print json string to stdout
func PrintJson(data []byte, pretty bool) {
	var err error
	var jsonString []byte

	if pretty {
		jsonString, err = json.MarshalIndent(json.RawMessage(data), "", " ")
	} else {
		jsonString, err = json.Marshal(json.RawMessage(data))
	}
	if err != nil {
		logger.Fatal().
			Err(err).
			Msg("failed to marshal json string")
	}

	fmt.Print(string(jsonString))
}

// FileExists check file exists
func FileExists(filename string) bool {
	info, err := os.Stat(filename)
	if os.IsNotExist(err) {
		return false
	}
	return !info.IsDir()
}

// NewLogger init logger
func NewLogger() zerolog.Logger {
	zerolog.CallerMarshalFunc = func(pc uintptr, file string, line int) string {
		short := file
		for i := len(file) - 1; i > 0; i-- {
			if file[i] == '/' {
				short = file[i+1:]
				break
			}
		}
		file = short
		return file + ":" + strconv.Itoa(line)
	}
	return zerolog.New(
		zerolog.ConsoleWriter{Out: os.Stderr, TimeFormat: time.RFC3339},
	).Level(zerolog.InfoLevel).With().Timestamp().Caller().Logger()
}

// SetLoggingDebug set debug level
func SetLoggingDebug() {
	zerolog.SetGlobalLevel(zerolog.DebugLevel)
}