err and const

1 files changed, 15 insertions, 7 deletions

diff --git a/rabbit.go b/rabbit.go
index d70d835..01e1278 100644
--- a/rabbit.go
+++ b/rabbit.go
@@ -8,12 +8,20 @@ import (
 )
 
 const (
-	invalidKeyLen = "rabbitio: key must be 16 byte len, not more not less"
-	invalidIVXLen = "rabbitio: iv must be 8 byte len or nothing (zero) at all"
+	RabbitKeyLen = 0x10
+	RabbitIVXLen = 0x08
+)
+
+var (
+	ErrInvalidKey = errors.New("rabbitio: key must be 16 byte len, not more not less")
+	ErrInvalidIVX = errors.New("rabbitio: iv must be 8 byte len or nothing (zero) at all")
 )
 
 var aro = []uint32{
-	0x4D34D34D, 0xD34D34D3, 0x34D34D34, 0x4D34D34D, 0xD34D34D3, 0x34D34D34, 0x4D34D34D, 0xD34D34D3,
+	0x4D34D34D, 0xD34D34D3, 
+	0x34D34D34, 0x4D34D34D, 
+	0xD34D34D3, 0x34D34D34, 
+	0x4D34D34D, 0xD34D34D3,
 }
 
 type rabbitCipher struct {
@@ -28,11 +36,11 @@ type rabbitCipher struct {
 // according to RFC 4503, key must be 16 byte len, iv on the other hand is optional but
 // must be either zero len or 8 byte len, error will be returned on wrong key/iv len
 func NewCipher(key []byte, iv []byte) (cipher.Stream, error) {
-	if len(key) != 0x10 {
-		return nil, errors.New(invalidKeyLen)
+	if len(key) != RabbitKeyLen {
+		return nil, ErrInvalidKey
 	}
-	if len(iv) != 0x00 && len(iv) != 0x08 {
-		return nil, errors.New(invalidIVXLen)
+	if len(iv) != 0x00 && len(iv) != RabbitIVXLen {
+		return nil, ErrInvalidIVX
 	}
 	var k [0x04]uint32
 	for i := range k {