Error Handling

application.go

@@ -1,5 +1,7 @@
 package tapir
 
+
+// Application defines the interface for all Tapir Applications
 type Application interface {
 	NewInstance() Application
 	Init(connection *Connection)

auth_app.go

@@ -12,18 +12,26 @@ import (
 	"time"
 )
 
-type AuthApp struct {
-}
-
+// AuthMessage is exchanged between peers to obtain the Auth Capability
 type AuthMessage struct {
 	LongTermPublicKey  ed25519.PublicKey
 	EphemeralPublicKey ed25519.PublicKey
 }
 
+// AuthCapability defines the Authentication Capability granted by AuthApp
+const AuthCapability = "AUTH"
+
+// AuthApp is the concrete Application type that handles Authentication
+type AuthApp struct {
+}
+
+// NewInstance creates a new instance of the AuthApp
 func (ea AuthApp) NewInstance() Application {
 	return new(AuthApp)
 }
 
+// Init runs the entire AuthApp protocol, at the end of the protocol either the connection is granted AUTH capability
+// or the connection is closed.
 func (ea AuthApp) Init(connection *Connection) {
 	longTermPubKey := ed25519.PublicKey(connection.ID.PublicKeyBytes())
 	epk, esk, _ := ed25519.GenerateKey(rand.Reader)
@@ -85,8 +93,9 @@ func (ea AuthApp) Init(connection *Connection) {
 	remoteChallenge := connection.Expect()
 	if subtle.ConstantTimeCompare(challengeBytes, remoteChallenge) == 1 {
 		connection.SetHostname(utils.GetTorV3Hostname(remoteAuthMessage.LongTermPublicKey))
-		connection.SetCapability("AUTH")
+		connection.SetCapability(AuthCapability)
 	} else {
 		log.Errorf("Failed Decrypt Challenge: [%x] [%x]\n", remoteChallenge, challengeBytes)
+		connection.conn.Close()
 	}
 }

cmd/main.go

@@ -12,7 +12,7 @@ import (
 	"time"
 )
 
-// Simple App is a trivial implementation of a basic p2p application
+// SimpleApp is a trivial implementation of a basic p2p application
 type SimpleApp struct {
 	tapir.AuthApp
 }
@@ -27,7 +27,7 @@ func (ea SimpleApp) Init(connection *tapir.Connection) {
 	// First run the Authentication App
 	ea.AuthApp.Init(connection)
 
-	if connection.HasCapability("AUTH") {
+	if connection.HasCapability(tapir.AuthCapability) {
 		// The code for out simple application (We just send and receive "Hello"
 		connection.Send([]byte("Hello"))
 		message := connection.Expect()
@@ -53,7 +53,7 @@ func main() {
 	// Start a Client to Connect to the Server
 	go client(acn, pubkey)
 
-	// Start the Server running the Echo App.
+	// Start the Server running the Simple App.
 	var service tapir.Service
 	service = new(tapir.BaseOnionService)
 	service.Start(acn, sk, id)
@@ -69,10 +69,14 @@ func client(acn connectivity.ACN, key ed25519.PublicKey) {
 	var client tapir.Service
 	client = new(tapir.BaseOnionService)
 	client.Start(acn, sk, id)
-	client.Connect(utils.GetTorV3Hostname(key), SimpleApp{})
+	cid,_ := client.Connect(utils.GetTorV3Hostname(key), SimpleApp{})
 
 	// Once connected, it shouldn't take long to authenticate and run the application. So for the purposes of this demo
 	// we will wait a little while then exit.
 	time.Sleep(time.Second * 5)
+
+	conn,_ := client.GetConnection(cid)
+	log.Debugf("Client has Auth: %v", conn.HasCapability(tapir.AuthCapability))
+
 	os.Exit(0)
 }

service.go

@@ -15,12 +15,17 @@ import (
 	"sync"
 )
 
+
+// Service defines the interface for a Tapir Service
 type Service interface {
 	Start(acn connectivity.ACN, privateKey ed25519.PrivateKey, identity identity.Identity)
-	Connect(hostname string, application Application) error
+	Connect(hostname string, application Application) (string, error)
 	Listen(application Application) error
+	GetConnection(connectionID string) (*Connection, error)
 }
 
+
+// Connection defines a Tapir Connection
 type Connection struct {
 	hostname     string
 	conn         net.Conn
@@ -32,6 +37,7 @@ type Connection struct {
 	Outbound     bool
 }
 
+// NewConnection creates a new Connection
 func NewConnection(id identity.Identity, hostname string, outbound bool, conn net.Conn, app Application) *Connection {
 	connection := new(Connection)
 	connection.hostname = hostname
@@ -43,25 +49,33 @@ func NewConnection(id identity.Identity, hostname string, outbound bool, conn ne
 	return connection
 }
 
+// SetHostname sets the hostname on the connection
 func (c *Connection) SetHostname(hostname string) {
 	log.Debugf("[%v -- %v] Asserting Remote Hostname: %v", c.ID.Hostname(), c.hostname, hostname)
 	c.hostname = hostname
 }
 
+// SetCapability sets a capability on the connection
 func (c *Connection) SetCapability(name string) {
 	log.Debugf("[%v -- %v] Setting Capability %v", c.ID.Hostname(), c.hostname, name)
 	c.capabilities.Store(name, true)
 }
 
+// HasCapability checks if the connection has a given capability
 func (c *Connection) HasCapability(name string) bool {
 	_, ok := c.capabilities.Load(name)
 	return ok
 }
 
+// Expect blocks and reads a single Tapir packet (1024 bytes), from the connection.
 func (c *Connection) Expect() []byte {
 	buffer := make([]byte, 1024)
-	// TODO handle ERROR
-	io.ReadFull(c.conn, buffer)
+	n, err := io.ReadFull(c.conn, buffer)
+
+	if n != 1024 || err != nil {
+		log.Errorf("[%v -> %v] Wire Error Reading, Read %d bytes, Error: %v", c.hostname, c.ID.Hostname(), n, err)
+		return []byte{}
+	}
 	//log.Debugf("[%v -> %v] Wire Receive: %x", c.hostname, c.ID.Hostname(), buffer)
 
 	if c.encrypted {
@@ -79,11 +93,14 @@ func (c *Connection) Expect() []byte {
 	return buffer[2 : len+2]
 }
 
+// SetEncryptionKey turns on application-level encryption on the connection using the given key.
 func (c *Connection) SetEncryptionKey(key [32]byte) {
 	c.key = key
 	c.encrypted = true
 }
 
+
+// Send writes a given message to a Tapir packet (of 1024 bytes in length).
 func (c *Connection) Send(message []byte) {
 
 	maxLength := 1024
@@ -104,6 +121,7 @@ func (c *Connection) Send(message []byte) {
 	c.conn.Write(buffer)
 }
 
+// BaseOnionService is a concrete implementation of the service interface over Tor onion services.
 type BaseOnionService struct {
 	connections sync.Map
 	acn         connectivity.ACN
@@ -111,6 +129,9 @@ type BaseOnionService struct {
 	privateKey  ed25519.PrivateKey
 }
 
+
+// Start initializes a BaseOnionService with a given private key and identity
+// The private key is needed to initialize the Onion listen socket, ideally we could just pass an Identity in here.
 func (s *BaseOnionService) Start(acn connectivity.ACN, sk ed25519.PrivateKey, id identity.Identity) {
 	// run add onion
 	// get listen context
@@ -119,24 +140,42 @@ func (s *BaseOnionService) Start(acn connectivity.ACN, sk ed25519.PrivateKey, id
 	s.privateKey = sk
 }
 
-func (s *BaseOnionService) GetConnection(hostname string) error {
-	return errors.New("no connection found")
+
+// GetConnection returns a connection for a given hostname.
+func (s *BaseOnionService) GetConnection(connectionID string) (*Connection, error) {
+	conn,ok := s.connections.Load(connectionID)
+	if !ok {
+		return nil, errors.New("no connection found")
+	}
+	connection := conn.(*Connection)
+	return connection, nil
 }
 
-func (s *BaseOnionService) Connect(hostname string, app Application) error {
+// Connect initializes a new outbound connection to the given peer, using the defined Application
+func (s *BaseOnionService) Connect(hostname string, app Application) (string, error) {
 	// connects to a remote server
 	// spins off to a connection struct
 	log.Debugf("Connecting to %v", hostname)
 	conn, _, err := s.acn.Open(hostname)
 	if err == nil {
-		log.Debugf("Connected to %v", hostname)
-		s.connections.Store(hostname, NewConnection(s.id, hostname, true, conn, app.NewInstance()))
-		return nil
+		connectionID := s.getNewConnectionID()
+		log.Debugf("Connected to %v [%v]", hostname, connectionID)
+		s.connections.Store(connectionID, NewConnection(s.id, hostname, true, conn, app.NewInstance()))
+		return connectionID, nil
 	}
 	log.Debugf("Error connecting to %v %v", hostname, err)
-	return err
+	return "", err
 }
 
+func (s *BaseOnionService) getNewConnectionID() string {
+	id := make([]byte, 10)
+	rand.Read(id)
+	connectionID := "connection-" + base64.StdEncoding.EncodeToString(id)
+	return connectionID
+}
+
+// Listen starts a blocking routine that waits for incoming connections and initializes connections with them based
+// on the given Application.
 func (s *BaseOnionService) Listen(app Application) error {
 	// accepts a new connection
 	// spins off to a connection struct
@@ -146,9 +185,7 @@ func (s *BaseOnionService) Listen(app Application) error {
 		for {
 			conn, err := ls.Accept()
 			if err == nil {
-				id := make([]byte, 10)
-				rand.Read(id)
-				tempHostname := "unknown-" + base64.StdEncoding.EncodeToString(id)
+				tempHostname := s.getNewConnectionID()
 				log.Debugf("Accepted connection from %v", tempHostname)
 				s.connections.Store(tempHostname, NewConnection(s.id, tempHostname, false, conn, app.NewInstance()))
 			} else {