role is now part of kd

1 files changed, 7 insertions, 6 deletions

diff --git a/satp/crypto-kd-aesctr.go b/satp/crypto-kd-aesctr.go
index 749e3dc..b3f2907 100644
--- a/satp/crypto-kd-aesctr.go
+++ b/satp/crypto-kd-aesctr.go
@@ -46,15 +46,16 @@ const (
 type AESCTRKeyDerivation struct {
 	cipher cipher.Block
 	salt   []byte
+	role   KDRole
 }
 
-func (kd *AESCTRKeyDerivation) generateCTR(role KDRole, dir Direction, usage KeyUsage, sequenceNumber uint32, ctr []byte) {
+func (kd *AESCTRKeyDerivation) generateCTR(dir Direction, usage KeyUsage, sequenceNumber uint32, ctr []byte) {
 	ctr[aes.BlockSize-1] = 0
 	ctr[aes.BlockSize-2] = 0
 	subtle.ConstantTimeCopy(1, ctr[:len(kd.salt)], kd.salt)
 
 	keyID := [8]byte{}
-	binary.BigEndian.PutUint32(keyID[:4], getKDLabel(role, dir, usage))
+	binary.BigEndian.PutUint32(keyID[:4], getKDLabel(kd.role, dir, usage))
 	binary.BigEndian.PutUint32(keyID[4:], sequenceNumber)
 
 	// unfortunately crypto.xorBytes is not exported...
@@ -65,11 +66,11 @@ func (kd *AESCTRKeyDerivation) generateCTR(role KDRole, dir Direction, usage Key
 	}
 }
 
-func (kd *AESCTRKeyDerivation) Generate(role KDRole, dir Direction, usage KeyUsage, sequenceNumber uint32, out []byte) error {
+func (kd *AESCTRKeyDerivation) Generate(dir Direction, usage KeyUsage, sequenceNumber uint32, out []byte) error {
 	// this needs to stay in this function so that the go compiler can detect that it doesn't escape
 	// from this function and whence will get allocated on the stack
 	ctr := [aes.BlockSize]byte{}
-	kd.generateCTR(role, dir, usage, sequenceNumber, ctr[:])
+	kd.generateCTR(dir, usage, sequenceNumber, ctr[:])
 	for i := range out { // unfortunately there is no memset-style function in go...
 		out[i] = 0
 	}
@@ -78,12 +79,12 @@ func (kd *AESCTRKeyDerivation) Generate(role KDRole, dir Direction, usage KeyUsa
 	return nil
 }
 
-func NewAESCTRKeyDerivation(key, salt []byte) (KeyDerivation, error) {
+func NewAESCTRKeyDerivation(key, salt []byte, role KDRole) (KeyDerivation, error) {
 	if len(salt) != AES_CTR_KD_SALT_LENGTH {
 		return nil, errors.New("invalid salt size: " + strconv.Itoa(len(salt)))
 	}
 
-	kd := &AESCTRKeyDerivation{salt: salt}
+	kd := &AESCTRKeyDerivation{salt: salt, role: role}
 
 	var err error
 	if kd.cipher, err = aes.NewCipher(key); err != nil {