feat: import messages from go version

go-exporter/crypt.go

@@ -0,0 +1,57 @@
+package main
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/rand"
+	"errors"
+	"io"
+)
+
+// Encrypt encrypts data using 256-bit AES-GCM.  This both hides the content of
+// the data and provides a check that it hasn't been altered. Output takes the
+// form nonce|ciphertext|tag where '|' indicates concatenation.
+func Encrypt(plaintext []byte, key [32]byte) (ciphertext []byte, err error) {
+	block, err := aes.NewCipher(key[:])
+	if err != nil {
+		return nil, err
+	}
+
+	gcm, err := cipher.NewGCM(block)
+	if err != nil {
+		return nil, err
+	}
+
+	nonce := make([]byte, gcm.NonceSize())
+	_, err = io.ReadFull(rand.Reader, nonce)
+	if err != nil {
+		return nil, err
+	}
+
+	return gcm.Seal(nonce, nonce, plaintext, nil), nil
+}
+
+// Decrypt decrypts data using 256-bit AES-GCM.  This both hides the content of
+// the data and provides a check that it hasn't been altered. Expects input
+// form nonce|ciphertext|tag where '|' indicates concatenation.
+func Decrypt(ciphertext []byte, key [32]byte) (plaintext []byte, err error) {
+	block, err := aes.NewCipher(key[:])
+	if err != nil {
+		return nil, err
+	}
+
+	gcm, err := cipher.NewGCM(block)
+	if err != nil {
+		return nil, err
+	}
+
+	if len(ciphertext) < gcm.NonceSize() {
+		return nil, errors.New("malformed ciphertext")
+	}
+
+	return gcm.Open(nil,
+		ciphertext[:gcm.NonceSize()],
+		ciphertext[gcm.NonceSize():],
+		nil,
+	)
+}