NATS backend support

backends/nats/helpers.go

@@ -0,0 +1,75 @@
+package nats
+
+import (
+	"crypto/rand"
+	"errors"
+	"golang.org/x/crypto/chacha20poly1305"
+	"os"
+	"time"
+)
+
+// Simple helper function to convert config int to time.Duration
+func helperSecondsToDuration(seconds int) time.Duration {
+	return time.Duration(seconds) * time.Second
+}
+
+// Simple helper function to check file exists
+func exists(path string, checkDirectory bool) (bool, error) {
+	info, err := os.Stat(path)
+	if !checkDirectory && err == nil && !info.IsDir() {
+		return true, nil
+	}
+	if checkDirectory && err == nil && info.IsDir() {
+		return true, nil
+	}
+	if os.IsNotExist(err) {
+		return false, nil
+	}
+	return false, err
+}
+
+// Simple helper function to check file is readable
+func fileExistsAndIsReadable(path string) error {
+	exists, err := exists(path, false)
+	if err != nil {
+		return err
+	}
+	if !exists {
+		return errors.New("file does not exist")
+	}
+	fil, err := os.OpenFile(path, os.O_RDONLY, 0)
+	if err != nil {
+		return err
+	}
+	fil.Close()
+	return nil
+}
+
+// Simple encryption helper
+func helperEncrypt(key []byte, plaintext []byte) ([]byte, error) {
+	var ciphertext []byte
+	aead, err := chacha20poly1305.NewX(key)
+	if err != nil {
+		return nil, err
+	}
+	nonce := make([]byte, aead.NonceSize(), aead.NonceSize()+len(plaintext)+aead.Overhead())
+	_, err = rand.Read(nonce)
+	if err != nil {
+		return nil, err
+	}
+	ciphertext = aead.Seal(nonce, nonce, plaintext, nil)
+	return ciphertext, nil
+}
+
+// Simple decryption helper
+func helperDecrypt(key []byte, ciphertext []byte) ([]byte, error) {
+	aead, err := chacha20poly1305.NewX(key)
+	if err != nil {
+		return nil, err
+	}
+	if len(ciphertext) < aead.NonceSize() {
+		return nil, errors.New("ciphertext too short")
+	}
+	nonce, cipher := ciphertext[:aead.NonceSize()], ciphertext[aead.NonceSize():]
+	return aead.Open(nil, nonce, cipher, nil)
+}