Merge pull request #53 from mpetrun5/early-data-api

Early data api

src/@types/handshake-interface.ts

@@ -5,6 +5,7 @@ import PeerId from "peer-id";
 export interface IHandshake {
   session: NoiseSession;
   remotePeer: PeerId;
+  remoteEarlyData: Buffer;
   encrypt(plaintext: bytes, session: NoiseSession): bytes;
   decrypt(ciphertext: bytes, session: NoiseSession): {plaintext: bytes; valid: boolean};
 }

src/@types/libp2p.ts

@@ -14,6 +14,7 @@ export interface INoiseConnection {
 
 export type SecureOutbound = {
   conn: any;
+  remoteEarlyData: Buffer;
   remotePeer: PeerId;
 }
 

src/handshake-ik.ts

@@ -22,6 +22,7 @@ export class IKHandshake implements IHandshake {
   public isInitiator: boolean;
   public session: NoiseSession;
   public remotePeer!: PeerId;
+  public remoteEarlyData: Buffer;
 
   private payload: bytes;
   private prologue: bytes32;
@@ -49,6 +50,7 @@ export class IKHandshake implements IHandshake {
     }
     this.ik = handshake || new IK();
     this.session = this.ik.initSession(this.isInitiator, this.prologue, this.staticKeypair, remoteStaticKey);
+    this.remoteEarlyData = Buffer.alloc(0)
   }
 
   public async stage0(): Promise<void> {
@@ -73,6 +75,7 @@ export class IKHandshake implements IHandshake {
         const decodedPayload = await decodePayload(plaintext);
         this.remotePeer = this.remotePeer || await getPeerIdFromPayload(decodedPayload);
         await verifySignedPayload(this.session.hs.rs, decodedPayload, this.remotePeer);
+        this.setRemoteEarlyData(decodedPayload.data);
         logger("IK Stage 0 - Responder successfully verified payload!");
         logRemoteEphemeralKey(this.session.hs.re)
       } catch (e) {
@@ -97,6 +100,7 @@ export class IKHandshake implements IHandshake {
         const decodedPayload = await decodePayload(plaintext);
         this.remotePeer = this.remotePeer || await getPeerIdFromPayload(decodedPayload);
         await verifySignedPayload(receivedMessageBuffer.ns.slice(0, 32), decodedPayload, this.remotePeer);
+        this.setRemoteEarlyData(decodedPayload.data);
         logger("IK Stage 1 - Initiator successfully verified payload!");
         logRemoteEphemeralKey(this.session.hs.re)
       } catch (e) {
@@ -142,4 +146,10 @@ export class IKHandshake implements IHandshake {
       return encryption ? session.cs2 : session.cs1;
     }
   }
+
+  private setRemoteEarlyData(data: Uint8Array|null|undefined): void {
+    if(data){
+      this.remoteEarlyData = Buffer.from(data.buffer, data.byteOffset, data.length);
+    }
+  }
 }

src/handshake-xx-fallback.ts

@@ -70,6 +70,7 @@ export class XXFallbackHandshake extends XXHandshake {
         const decodedPayload = await decodePayload(plaintext);
         this.remotePeer = this.remotePeer || await getPeerIdFromPayload(decodedPayload);
         await verifySignedPayload(this.session.hs.rs, decodedPayload, this.remotePeer);
+        this.setRemoteEarlyData(decodedPayload.data)
       } catch (e) {
         throw new Error(`Error occurred while verifying signed payload from responder: ${e.message}`);
       }

src/handshake-xx.ts

@@ -26,6 +26,7 @@ export class XXHandshake implements IHandshake {
   public isInitiator: boolean;
   public session: NoiseSession;
   public remotePeer!: PeerId;
+  public remoteEarlyData: Buffer;
 
   protected payload: bytes;
   protected connection: WrappedConnection;
@@ -53,6 +54,7 @@ export class XXHandshake implements IHandshake {
     }
     this.xx = handshake || new XX();
     this.session = this.xx.initSession(this.isInitiator, this.prologue, this.staticKeypair);
+    this.remoteEarlyData = Buffer.alloc(0)
   }
 
   // stage 0
@@ -94,6 +96,7 @@ export class XXHandshake implements IHandshake {
         const decodedPayload = await decodePayload(plaintext);
         this.remotePeer = this.remotePeer || await getPeerIdFromPayload(decodedPayload);
         this.remotePeer = await verifySignedPayload(receivedMessageBuffer.ns, decodedPayload, this.remotePeer);
+        this.setRemoteEarlyData(decodedPayload.data)
       } catch (e) {
         throw new Error(`Error occurred while verifying signed payload: ${e.message}`);
       }
@@ -127,6 +130,7 @@ export class XXHandshake implements IHandshake {
         const decodedPayload = await decodePayload(plaintext);
         this.remotePeer = this.remotePeer || await getPeerIdFromPayload(decodedPayload);
         await verifySignedPayload(this.session.hs.rs, decodedPayload, this.remotePeer);
+        this.setRemoteEarlyData(decodedPayload.data)
       } catch (e) {
         throw new Error(`Error occurred while verifying signed payload: ${e.message}`);
       }
@@ -160,4 +164,10 @@ export class XXHandshake implements IHandshake {
       return encryption ? session.cs2 : session.cs1;
     }
   }
+
+  protected setRemoteEarlyData(data: Uint8Array|null|undefined): void {
+    if(data){
+      this.remoteEarlyData = Buffer.from(data.buffer, data.byteOffset, data.length);
+    }
+  }
 }

src/noise.ts

@@ -85,6 +85,7 @@ export class Noise implements INoiseConnection {
 
     return {
       conn,
+      remoteEarlyData: handshake.remoteEarlyData,
       remotePeer: handshake.remotePeer,
     }
   }
@@ -115,6 +116,7 @@ export class Noise implements INoiseConnection {
 
     return {
       conn,
+      remoteEarlyData: handshake.remoteEarlyData,
       remotePeer: handshake.remotePeer
     };
   }

test/noise.test.ts

@@ -336,4 +336,30 @@ describe("Noise", () => {
       assert(false, e.message);
     }
   });
+
+  it("should accept and return early data from remote peer", async() => {
+    try {
+      const localPeerEarlyData = Buffer.from('early data')
+      const staticKeysInitiator = generateKeypair();
+      const noiseInit = new Noise(staticKeysInitiator.privateKey, localPeerEarlyData);
+      const staticKeysResponder = generateKeypair();
+      const noiseResp = new Noise(staticKeysResponder.privateKey);
+
+      // Prepare key cache for noise pipes
+      KeyCache.store(localPeer, staticKeysInitiator.publicKey);
+      KeyCache.store(remotePeer, staticKeysResponder.publicKey);
+
+      const [inboundConnection, outboundConnection] = DuplexPair();
+      const [outbound, inbound] = await Promise.all([
+        noiseInit.secureOutbound(localPeer, outboundConnection, remotePeer),
+        noiseResp.secureInbound(remotePeer, inboundConnection),
+      ]);
+
+      assert(inbound.remoteEarlyData.equals(localPeerEarlyData))
+      assert(outbound.remoteEarlyData.equals(Buffer.alloc(0)))
+    } catch (e) {
+      console.error(e);
+      assert(false, e.message);
+    }
+  });
 });