From 0fa987cfe10cef2d8d398f57edf2c7e67ae3ab08 Mon Sep 17 00:00:00 2001
From: allen0091 <44120584+allen0091@users.noreply.github.com>
Date: Thu, 12 Dec 2024 18:26:11 +0800
Subject: [PATCH] Split ConcatenatedNonce to Ni & Nr (#13)

---
 pkg/context/context.go     |  7 ++++++-
 pkg/ike/handler/handler.go | 24 ++++++++++++++++--------
 2 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/pkg/context/context.go b/pkg/context/context.go
index b7ed7cf..9885e9d 100644
--- a/pkg/context/context.go
+++ b/pkg/context/context.go
@@ -134,7 +134,8 @@ type IKESecurityAssociation struct {
 	InitiatorSignedOctets []byte
 
 	// Used for key generating
-	ConcatenatedNonce []byte
+	NonceInitiator []byte
+	NonceResponder []byte
 
 	// State for IKE_AUTH
 	State uint8
@@ -180,6 +181,10 @@ type ChildSecurityAssociation struct {
 	EnableEncapsulate bool
 	N3IWFPort         int
 	NATPort           int
+
+	// Used for key generating
+	NonceInitiator []byte
+	NonceResponder []byte
 }
 
 type UDPSocketInfo struct {
diff --git a/pkg/ike/handler/handler.go b/pkg/ike/handler/handler.go
index 61b9ab5..fb9aeea 100644
--- a/pkg/ike/handler/handler.go
+++ b/pkg/ike/handler/handler.go
@@ -111,14 +111,16 @@ func HandleIKESAINIT(
 			PrfInfo:   prf.DecodeTransform(n3ueSelf.Proposal.PseudorandomFunction[0]),
 			DhInfo:    dh.DecodeTransform(n3ueSelf.Proposal.DiffieHellmanGroup[0]),
 		},
-		ConcatenatedNonce: append(n3ueSelf.LocalNonce, remoteNonce...),
+		NonceInitiator: n3ueSelf.LocalNonce,
+		NonceResponder: remoteNonce,
 		ResponderSignedOctets: append(n3ueSelf.N3IWFUe.N3IWFIKESecurityAssociation.
 			ResponderSignedOctets, remoteNonce...),
 		UEIsBehindNAT:    ueIsBehindNAT,
 		N3IWFIsBehindNAT: n3iwfIsBehindNAT,
 	}
+	ConcatenatedNonce := append(ikeSecurityAssociation.NonceInitiator, ikeSecurityAssociation.NonceResponder...)
 
-	err = ikeSecurityAssociation.IKESAKey.GenerateKeyForIKESA(ikeSecurityAssociation.ConcatenatedNonce,
+	err = ikeSecurityAssociation.IKESAKey.GenerateKeyForIKESA(ConcatenatedNonce,
 		sharedKeyExchangeData, ikeSecurityAssociation.LocalSPI, ikeSecurityAssociation.RemoteSPI)
 	if err != nil {
 		ikeLog.Errorf("Generate key for IKE SA failed: %+v", err)
@@ -545,9 +547,13 @@ func HandleIKEAUTH(
 		}
 		// Select TCP traffic
 		childSecurityAssociationContext.SelectedIPProtocol = unix.IPPROTO_TCP
+		childSecurityAssociationContext.NonceInitiator = ikeSecurityAssociation.NonceInitiator
+		childSecurityAssociationContext.NonceResponder = ikeSecurityAssociation.NonceResponder
+		concatenatedNonce := append(childSecurityAssociationContext.NonceInitiator,
+			childSecurityAssociationContext.NonceResponder...)
 
 		err = childSecurityAssociationContext.GenerateKeyForChildSA(ikeSecurityAssociation.IKESAKey,
-			ikeSecurityAssociation.ConcatenatedNonce)
+			concatenatedNonce)
 		if err != nil {
 			ikeLog.Errorf("HandleIKEAUTH Generate key for child SA failed: %+v", err)
 			return
@@ -647,6 +653,7 @@ func HandleCREATECHILDSA(
 	var responseTrafficSelectorInitiator *ike_message.TrafficSelectorInitiator
 	var responseTrafficSelectorResponder *ike_message.TrafficSelectorResponder
 	var err error
+	var nonce []byte
 
 	for _, ikePayload := range message.Payloads {
 		switch ikePayload.Type() {
@@ -679,7 +686,7 @@ func HandleCREATECHILDSA(
 			}
 		case ike_message.TypeNiNr:
 			responseNonce := ikePayload.(*ike_message.Nonce)
-			ikeSecurityAssociation.ConcatenatedNonce = responseNonce.NonceData
+			nonce = responseNonce.NonceData
 		}
 	}
 
@@ -705,9 +712,6 @@ func HandleCREATECHILDSA(
 		return
 	}
 	localNonce := localNonceBigInt.Bytes()
-	ikeSecurityAssociation.ConcatenatedNonce = append(
-		ikeSecurityAssociation.ConcatenatedNonce,
-		localNonce...)
 	ikePayload.BuildNonce(localNonce)
 
 	ikeMessage := ike_message.NewMessage(
@@ -753,9 +757,13 @@ func HandleCREATECHILDSA(
 	}
 	// Select GRE traffic
 	childSecurityAssociationContextUserPlane.SelectedIPProtocol = unix.IPPROTO_GRE
+	childSecurityAssociationContextUserPlane.NonceInitiator = nonce
+	childSecurityAssociationContextUserPlane.NonceResponder = localNonce
+	concatenatedNonce := append(childSecurityAssociationContextUserPlane.NonceInitiator,
+		childSecurityAssociationContextUserPlane.NonceResponder...)
 
 	err = childSecurityAssociationContextUserPlane.GenerateKeyForChildSA(ikeSecurityAssociation.IKESAKey,
-		ikeSecurityAssociation.ConcatenatedNonce)
+		concatenatedNonce)
 	if err != nil {
 		ikeLog.Errorf("HandleCREATECHILDSA() Generate key for child SA failed: %+v", err)
 		return