refactor errors

core/user_cipher_keys.go

@@ -2,7 +2,6 @@ package core
 
 import (
 	"crypto/sha256"
-	"errors"
 	"go-nkode/util"
 	"golang.org/x/crypto/bcrypt"
 )
@@ -49,7 +48,7 @@ func NewUserCipherKeys(kp *KeypadDimension, setVals []uint64, maxNKodeLen int) (
 
 func (u *UserCipherKeys) PadUserMask(userMask []uint64, setVals []uint64) ([]uint64, error) {
 	if len(userMask) > u.MaxNKodeLen {
-		return nil, errors.New("user mask length exceeds max nkode length")
+		return nil, ErrUserMaskTooLong
 	}
 	paddedUserMask := make([]uint64, len(userMask))
 	copy(paddedUserMask, userMask)
@@ -153,7 +152,10 @@ func (u *UserCipherKeys) DecipherMask(mask string, setVals []uint64, passcodeLen
 
 	passcodeSet := make([]uint64, passcodeLen)
 	for idx, setCipher := range decipheredMask[:passcodeLen] {
-		setIdx := util.IndexOf(setKeyRandComponent, setCipher)
+		setIdx, err := util.IndexOf(setKeyRandComponent, setCipher)
+		if err != nil {
+			return nil, err
+		}
 		passcodeSet[idx] = setVals[setIdx]
 	}
 	return passcodeSet, nil
@@ -175,6 +177,9 @@ func (u *UserCipherKeys) EncipherNKode(passcodeAttrIdx []int, customerAttrs Cust
 		}
 	}
 	mask, err := u.EncipherMask(passcodeSet, customerAttrs, *u.Kp)
+	if err != nil {
+		return nil, err
+	}
 	encipheredCode := EncipheredNKode{
 		Code: code,
 		Mask: mask,