changed symmetric key

Author: vk-rv

v2_local.go

@@ -21,19 +21,8 @@ const (
 // ErrMalformedToken indicates that obtained token was not properly formed
 var ErrMalformedToken = errors.New("token is malformed")
 
-// SymmetricKey is an abstraction for real key aimed at setting up strong typing and invariant.
-type SymmetricKey struct {
-	key []byte
-}
-
-// NewSymmetricKey is a constructor-like function which creates encryption key suitable for Encrypt() / Decrypt() functions.
-// Returns error in case when provided byte slice key length does not match to 32 bytes.
-func NewSymmetricKey(key []byte) (SymmetricKey, error) {
-	if l := len(key); l != chacha20poly1305.KeySize {
-		return SymmetricKey{}, fmt.Errorf("key length should be %d bytes, provided %d bytes slice", chacha20poly1305.KeySize, l)
-	}
-	return SymmetricKey{key: key}, nil
-}
+// SymmetricKey is used in encryption and decryption routines.
+type SymmetricKey []byte
 
 // PV2Local can be used as a global reference for protocol version 2 with local purpose.
 var PV2Local = NewPV2Local()
@@ -94,7 +83,7 @@ func (pv2 *ProtoV2Local) encrypt(key SymmetricKey, message []byte, optionalFoote
 
 	additionalData := preAuthenticationEncoding([]byte(header), nonce, optionalFooter)
 
-	aead, err := chacha20poly1305.NewX(key.key)
+	aead, err := chacha20poly1305.NewX(key)
 	if err != nil {
 		return "", fmt.Errorf("failed to create chacha20poly1305 aead: %w", err)
 	}
@@ -150,7 +139,7 @@ func (pv2 *ProtoV2Local) decrypt(token string, key SymmetricKey) ([]byte, []byte
 	nonce := bodyBytes[:nonceLen]
 	cipherText := bodyBytes[nonceLen:]
 
-	aead, err := chacha20poly1305.NewX(key.key)
+	aead, err := chacha20poly1305.NewX(key)
 	if err != nil {
 		return nil, nil, fmt.Errorf("failed to create chachapoly cipher: %w", err)
 	}

v2_local_test.go

@@ -13,21 +13,9 @@ import (
 func TestEncrypt(t *testing.T) {
 
 	setupKeys := func() (nullKey, fullKey, symmetricKey SymmetricKey, err error) {
-		nk := bytes.Repeat([]byte{0}, 32)
-		nullKey, err = NewSymmetricKey(nk)
-		if err != nil {
-			return SymmetricKey{}, SymmetricKey{}, SymmetricKey{}, err
-		}
-		fk := bytes.Repeat([]byte{0xff}, 32)
-		fullKey, err = NewSymmetricKey(fk)
-		if err != nil {
-			return SymmetricKey{}, SymmetricKey{}, SymmetricKey{}, err
-		}
-		sk, err := hex.DecodeString("707172737475767778797a7b7c7d7e7f808182838485868788898a8b8c8d8e8f")
-		if err != nil {
-			return SymmetricKey{}, SymmetricKey{}, SymmetricKey{}, err
-		}
-		symmetricKey, err = NewSymmetricKey(sk)
+		nullKey = bytes.Repeat([]byte{0}, 32)
+		fullKey = bytes.Repeat([]byte{0xff}, 32)
+		symmetricKey, err = hex.DecodeString("707172737475767778797a7b7c7d7e7f808182838485868788898a8b8c8d8e8f")
 		if err != nil {
 			return SymmetricKey{}, SymmetricKey{}, SymmetricKey{}, err
 		}
@@ -216,14 +204,10 @@ func TestEncrypt(t *testing.T) {
 
 func TestEncryptDecrypt(t *testing.T) {
 	pv2 := NewPV2Local()
-	kb, err := hex.DecodeString("707172737475767778797a7b7c7d7e7f808182838485868788898a8b8c8d8e8f")
+	k, err := hex.DecodeString("707172737475767778797a7b7c7d7e7f808182838485868788898a8b8c8d8e8f")
 	if err != nil {
 		t.Errorf("can't hex decode key")
 	}
-	k, err := NewSymmetricKey(kb)
-	if err != nil {
-		t.Errorf("can't create key: %v", err)
-	}
 
 	type AdditionalInformation struct {
 		Info   string `json:"info"`
@@ -308,12 +292,7 @@ func TestEncryptDecrypt(t *testing.T) {
 		t.Errorf("problem while encryption")
 	}
 
-	bk := bytes.Repeat([]byte{2}, 32)
-	badKey, err := NewSymmetricKey(bk)
-	if err != nil {
-		t.Errorf("problem while trying to make a new key")
-	}
-
+	badKey := bytes.Repeat([]byte{2}, 32)
 	if err = pv2.Decrypt(token, badKey).Err(); err == nil {
 		t.Errorf("error can't be nil because key is different")
 	}
@@ -368,17 +347,6 @@ func TestPreAuthenticationEncoding(t *testing.T) {
 	}
 }
 
-func TestWrongSizeEncryptionKey(t *testing.T) {
-	_, err := NewSymmetricKey(bytes.Repeat([]byte{0xff}, 32))
-	if err != nil {
-		t.Errorf("problem occurred: %v", err)
-	}
-	_, err = NewSymmetricKey(bytes.Repeat([]byte{0xff}, 31))
-	if err == nil {
-		t.Errorf("there must be error because of wrong key len")
-	}
-}
-
 func TestEncodeDecodeFooter(t *testing.T) {
 
 	// string footer