role is now part of kd

3 files changed, 45 insertions, 38 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 {
diff --git a/satp/crypto-kd-aesctr_test.go b/satp/crypto-kd-aesctr_test.go
index a36157c..030dc12 100644
--- a/satp/crypto-kd-aesctr_test.go
+++ b/satp/crypto-kd-aesctr_test.go
@@ -55,14 +55,16 @@ func TestAESCTRKeyDerivationNew(t *testing.T) {
 	}
 
 	for _, vector := range testvectors {
-		_, err := NewAESCTRKeyDerivation(vector.key, vector.salt)
-		if vector.valid {
-			if err != nil {
-				t.Fatal("unexpected error:", err)
-			}
-		} else {
-			if err == nil {
-				t.Fatalf("creating aes-ctr key derivation with key %v and salt %v should give an error", vector.key, vector.salt)
+		for _, role := range []KDRole{RoleLeft, RoleRight} {
+			_, err := NewAESCTRKeyDerivation(vector.key, vector.salt, role)
+			if vector.valid {
+				if err != nil {
+					t.Fatal("unexpected error:", err)
+				}
+			} else {
+				if err == nil {
+					t.Fatalf("creating aes-ctr key derivation with key %v and salt %v should give an error", vector.key, vector.salt)
+				}
 			}
 		}
 	}
@@ -91,14 +93,14 @@ func TestAESCTRKeyDerivationGenerateCtr(t *testing.T) {
 
 	for _, vector := range testvectors {
 		key := [aes.BlockSize]byte{}
-		kd, err := NewAESCTRKeyDerivation(key[:], vector.salt)
+		kd, err := NewAESCTRKeyDerivation(key[:], vector.salt, vector.role)
 		if err != nil {
 			t.Fatal("unexpected error:", err)
 		}
 		aesCTR := kd.(*AESCTRKeyDerivation)
 
 		ctr := [aes.BlockSize]byte{}
-		aesCTR.generateCTR(vector.role, vector.dir, vector.usage, vector.sequenceNumber, ctr[:])
+		aesCTR.generateCTR(vector.dir, vector.usage, vector.sequenceNumber, ctr[:])
 		if bytes.Compare(ctr[:], vector.ctr) != 0 {
 			t.Fatalf("resulting ctr is invalid, is: '%v', should be '%v'", ctr[:], vector.ctr)
 		}
@@ -106,40 +108,44 @@ func TestAESCTRKeyDerivationGenerateCtr(t *testing.T) {
 }
 
 func TestAESCTRKeyDerivationGenerate(t *testing.T) {
+	key := []byte{0x77, 0x67, 0xA3, 0x90, 0x3E, 0xB9, 0x22, 0x06, 0x87, 0xBF, 0xF8, 0xA1, 0x4E, 0x94, 0x0F, 0xA7}
+	salt := []byte{0x3D, 0x58, 0x3F, 0xC6, 0x70, 0xA9, 0x6B, 0xCF, 0x92, 0xDA, 0x27, 0x0D, 0x07, 0x67}
+	kdLeft, err := NewAESCTRKeyDerivation(key, salt, RoleLeft)
+	if err != nil {
+		t.Fatal("unexpected error:", err)
+	}
+	kdRight, err := NewAESCTRKeyDerivation(key, salt, RoleRight)
+	if err != nil {
+		t.Fatal("unexpected error:", err)
+	}
+
 	testvectors := []struct {
-		role           KDRole
+		kd             KeyDerivation
 		dir            Direction
 		usage          KeyUsage
 		sequenceNumber uint32
 		out            []byte
 	}{
-		{RoleLeft, Outbound, UsageEncryptKey, 0,
+		{kdLeft, Outbound, UsageEncryptKey, 0,
 			[]byte{0x46, 0x04, 0x12, 0x67, 0x0C, 0x7A, 0x20, 0x07, 0x67, 0xC5, 0x9A, 0xB4, 0xBE, 0x2E, 0xBE, 0x50,
 				0xE9, 0xBC, 0x04, 0x7C, 0x17, 0x54, 0x73, 0x02, 0x4A, 0x54, 0x28, 0x44, 0x6F, 0xFA, 0xD2, 0xB6}},
-		{RoleLeft, Inbound, UsageEncryptKey, 0x0012CA37,
+		{kdLeft, Inbound, UsageEncryptKey, 0x0012CA37,
 			[]byte{0x93, 0xEE, 0xC4, 0xD4, 0x94, 0xDA, 0x29, 0x72, 0x0C, 0xF5, 0xB6, 0x1D, 0x45, 0x3F, 0xA1, 0x19,
 				0xB0, 0x31, 0xB1, 0x7D, 0xA3, 0x78, 0x2C, 0x7A, 0x72, 0x19, 0x39, 0x4E, 0xEE, 0x40, 0x52, 0xDA}},
-		{RoleRight, Outbound, UsageEncryptSalt, 0x0012CA37,
+		{kdRight, Outbound, UsageEncryptSalt, 0x0012CA37,
 			[]byte{0x7C, 0x20, 0x7D, 0x35, 0xAD, 0x9C, 0xED, 0xC6, 0xE6, 0x16, 0xE4, 0xA9, 0x36, 0x3C, 0x49, 0xAA,
 				0xF4, 0xA9, 0x59, 0x0D, 0x6A, 0xC1, 0x63, 0xAB, 0x17, 0x3D, 0xA8, 0x9F, 0x3F, 0xD7, 0x10, 0xC3}},
-		{RoleRight, Outbound, UsageAuthKey, 0xE,
+		{kdRight, Outbound, UsageAuthKey, 0xE,
 			[]byte{0xE3, 0x26, 0x29, 0x37, 0xED, 0xF1, 0x36, 0x80, 0xB4, 0x8E, 0x6C, 0xF7, 0x7C, 0xEE, 0x8C, 0x49,
 				0xEA, 0x70, 0x6D, 0x24, 0x25, 0x35, 0xAF, 0x79, 0x7F, 0x02, 0x7C, 0x59, 0x2C, 0x7E, 0x41, 0x55}},
-		{RoleRight, Inbound, UsageAuthKey, 0xC,
+		{kdRight, Inbound, UsageAuthKey, 0xC,
 			[]byte{0x2C, 0xF9, 0x7A, 0x96, 0x17, 0x28, 0x52, 0xFD, 0xF6, 0x57, 0xC4, 0x86, 0x7D, 0xA8, 0x04, 0xE3,
 				0xB4, 0x23, 0xA6, 0xAE, 0x66, 0xF8, 0xB9, 0xCC, 0x79, 0x72, 0xA6, 0xB9, 0x54, 0x72, 0x7F, 0xF4}},
 	}
 
-	key := []byte{0x77, 0x67, 0xA3, 0x90, 0x3E, 0xB9, 0x22, 0x06, 0x87, 0xBF, 0xF8, 0xA1, 0x4E, 0x94, 0x0F, 0xA7}
-	salt := []byte{0x3D, 0x58, 0x3F, 0xC6, 0x70, 0xA9, 0x6B, 0xCF, 0x92, 0xDA, 0x27, 0x0D, 0x07, 0x67}
-	kd, err := NewAESCTRKeyDerivation(key, salt)
-	if err != nil {
-		t.Fatal("unexpected error:", err)
-	}
-
 	for _, vector := range testvectors {
 		out := [32]byte{}
-		kd.Generate(vector.role, vector.dir, vector.usage, vector.sequenceNumber, out[:])
+		vector.kd.Generate(vector.dir, vector.usage, vector.sequenceNumber, out[:])
 		if bytes.Compare(out[:], vector.out) != 0 {
 			t.Fatalf("resulting key material is invalid, is: '%v', should be '%v'", out[:], vector.out)
 		}
@@ -166,15 +172,15 @@ func TestAESCTRKeyDerivationGenerateRepeat(t *testing.T) {
 	}
 
 	for _, vector := range testvectors {
-		kd, err := NewAESCTRKeyDerivation(vector.key, vector.salt)
+		kd, err := NewAESCTRKeyDerivation(vector.key, vector.salt, vector.role)
 		if err != nil {
 			t.Fatal("unexpected error:", err)
 		}
 
 		out1 := make([]byte, vector.length)
 		out2 := buffer[128 : 128+vector.length]
-		kd.Generate(vector.role, vector.dir, vector.usage, vector.sequenceNumber, out1)
-		kd.Generate(vector.role, vector.dir, vector.usage, vector.sequenceNumber, out2)
+		kd.Generate(vector.dir, vector.usage, vector.sequenceNumber, out1)
+		kd.Generate(vector.dir, vector.usage, vector.sequenceNumber, out2)
 
 		if bytes.Compare(out1, out2) != 0 {
 			t.Fatalf("result of 2 consecutive key generations differ, out1: '%v', out2: '%v'", out1, out2)
@@ -190,7 +196,7 @@ func BenchmarkAESCTRKeyDerivationGenerateCtr(b *testing.B) {
 	var buffer [256]byte
 	rand.Read(buffer[:])
 
-	kd, err := NewAESCTRKeyDerivation(buffer[:16], buffer[16:30])
+	kd, err := NewAESCTRKeyDerivation(buffer[:16], buffer[16:30], RoleRight)
 	if err != nil {
 		b.Fatal("unexpected error:", err)
 	}
@@ -200,7 +206,7 @@ func BenchmarkAESCTRKeyDerivationGenerateCtr(b *testing.B) {
 	b.ResetTimer()
 
 	for i := 0; i < b.N; i++ {
-		aesCTR.generateCTR(RoleRight, Outbound, UsageAuthKey, 0xAA55AA55, ctr)
+		aesCTR.generateCTR(Outbound, UsageAuthKey, 0xAA55AA55, ctr)
 	}
 }
 
@@ -208,7 +214,7 @@ func BenchmarkAESCTRKeyDerivationGenerate(b *testing.B) {
 	var buffer [256]byte
 	rand.Read(buffer[:])
 
-	kd, err := NewAESCTRKeyDerivation(buffer[:16], buffer[16:30])
+	kd, err := NewAESCTRKeyDerivation(buffer[:16], buffer[16:30], RoleLeft)
 	if err != nil {
 		b.Fatal("unexpected error:", err)
 	}
@@ -217,6 +223,6 @@ func BenchmarkAESCTRKeyDerivationGenerate(b *testing.B) {
 	b.ResetTimer()
 
 	for i := 0; i < b.N; i++ {
-		kd.Generate(RoleLeft, Outbound, UsageEncryptKey, 0xdeadbeef, out)
+		kd.Generate(Outbound, UsageEncryptKey, 0xdeadbeef, out)
 	}
 }
diff --git a/satp/crypto-kd.go b/satp/crypto-kd.go
index 823c5bb..db52f77 100644
--- a/satp/crypto-kd.go
+++ b/satp/crypto-kd.go
@@ -56,7 +56,7 @@ const (
 )
 
 type KeyDerivation interface {
-	Generate(role KDRole, dir Direction, usage KeyUsage, sequenceNumber uint32, out []byte) error
+	Generate(dir Direction, usage KeyUsage, sequenceNumber uint32, out []byte) error
 }
 
 func getKDLabel(role KDRole, dir Direction, usage KeyUsage) uint32 {