First Cut of Applications + Bugs, Formatting

application/acceptallcontactmanager.go

@@ -0,0 +1,23 @@
+package application
+
+import (
+	"crypto/rsa"
+)
+
+// AcceptAllContactManager implements the contact manager interface an presumes
+// all connections are allowed.
+type AcceptAllContactManager struct {
+}
+
+// LookupContact returns that a contact is known and allowed to communicate for all cases.
+func (aacm *AcceptAllContactManager) LookupContact(hostname string, publicKey rsa.PublicKey) (allowed, known bool) {
+	return true, true
+}
+
+func (aacm *AcceptAllContactManager) GetContactDetails() (string, string) {
+	return "", ""
+}
+
+func (aacm *AcceptAllContactManager) ContactRequest(name string, message string) string {
+	return "Accepted"
+}

application/application.go

@@ -1,36 +1,134 @@
 package application
 
 import (
-	"errors"
+	"crypto/rsa"
+	"github.com/s-rah/go-ricochet"
 	"github.com/s-rah/go-ricochet/channels"
 	"github.com/s-rah/go-ricochet/connection"
+	"log"
+	"net"
+	"time"
 )
 
 // RicochetApplication bundles many useful constructs that are
 // likely standard in a ricochet application
 type RicochetApplication struct {
+	contactManager        ContactManagerInterface
+	privateKey            *rsa.PrivateKey
+	chatMessageHandler    func(*RicochetApplicationInstance, uint32, time.Time, string)
+	chatMessageAckHandler func(*RicochetApplicationInstance, uint32)
+}
+
+type RicochetApplicationInstance struct {
+	connection.AutoConnectionHandler
 	connection            *connection.Connection
+	RemoteHostname        string
+	ChatMessageHandler    func(*RicochetApplicationInstance, uint32, time.Time, string)
+	ChatMessageAckHandler func(*RicochetApplicationInstance, uint32)
 }
 
-// NewRicochetApplication ...
-func NewRicochetApplication(connection *connection.Connection) *RicochetApplication {
-	ra := new(RicochetApplication)
-	ra.connection = connection
-	return ra
+func (rai *RicochetApplicationInstance) GetContactDetails() (string, string) {
+	return "EchoBot", "I LIVE 😈😈!!!!"
 }
 
-// SendMessage ...
-func (ra *RicochetApplication) SendChatMessage(message string) error {
-	return ra.connection.Do(func() error {
-		channel := ra.connection.Channel("im.ricochet.chat", channels.Outbound)
+func (rai *RicochetApplicationInstance) ContactRequest(name string, message string) string {
+	return "Accepted"
+}
+
+func (rai *RicochetApplicationInstance) ContactRequestRejected() {
+}
+func (rai *RicochetApplicationInstance) ContactRequestAccepted() {
+}
+func (rai *RicochetApplicationInstance) ContactRequestError() {
+}
+
+func (rai *RicochetApplicationInstance) SendChatMessage(message string) {
+
+	// Technically this errors afte the second time but we can ignore it.
+	rai.connection.RequestOpenChannel("im.ricochet.chat", rai)
+
+	rai.connection.Do(func() error {
+		channel := rai.connection.Channel("im.ricochet.chat", channels.Outbound)
 		if channel != nil {
 			chatchannel, ok := (*channel.Handler).(*channels.ChatChannel)
 			if ok {
 				chatchannel.SendMessage(message)
 			}
-		} else {
-			return errors.New("")
 		}
 		return nil
 	})
 }
+
+func (rai *RicochetApplicationInstance) ChatMessage(messageID uint32, when time.Time, message string) bool {
+	go rai.ChatMessageHandler(rai, messageID, when, message)
+	return true
+}
+
+func (rai *RicochetApplicationInstance) ChatMessageAck(messageID uint32) {
+	rai.ChatMessageAckHandler(rai, messageID)
+}
+
+func (ra *RicochetApplication) Init(pk *rsa.PrivateKey, cm ContactManagerInterface) {
+	ra.privateKey = pk
+	ra.contactManager = cm
+	ra.chatMessageHandler = func(*RicochetApplicationInstance, uint32, time.Time, string) {}
+	ra.chatMessageAckHandler = func(*RicochetApplicationInstance, uint32) {}
+}
+
+func (ra *RicochetApplication) OnChatMessage(call func(*RicochetApplicationInstance, uint32, time.Time, string)) {
+	ra.chatMessageHandler = call
+}
+
+func (ra *RicochetApplication) OnChatMessageAck(call func(*RicochetApplicationInstance, uint32)) {
+	ra.chatMessageAckHandler = call
+}
+
+func (ra *RicochetApplication) handleConnection(conn net.Conn) {
+	rc, err := goricochet.NegotiateVersionInbound(conn)
+	if err != nil {
+		log.Printf("There was an error")
+		conn.Close()
+		return
+	}
+
+	ich := connection.HandleInboundConnection(rc)
+
+	err = ich.ProcessAuthAsServer(ra.privateKey, ra.contactManager.LookupContact)
+	if err != nil {
+		log.Printf("There was an error")
+		conn.Close()
+		return
+	}
+
+	rai := new(RicochetApplicationInstance)
+	rai.Init(ra.privateKey, "")
+	rai.RemoteHostname = rc.RemoteHostname
+	rai.connection = rc
+	rai.ChatMessageHandler = ra.chatMessageHandler
+	rai.ChatMessageAckHandler = ra.chatMessageAckHandler
+
+	rai.RegisterChannelHandler("im.ricochet.contact.request", func() channels.Handler {
+		contact := new(channels.ContactRequestChannel)
+		contact.Handler = rai
+		return contact
+	})
+	rai.RegisterChannelHandler("im.ricochet.chat", func() channels.Handler {
+		chat := new(channels.ChatChannel)
+		chat.Handler = rai
+		return chat
+	})
+	rc.Process(rai)
+}
+
+func (ra *RicochetApplication) Run(l net.Listener) {
+	if ra.privateKey == nil || ra.contactManager == nil {
+		return
+	}
+
+	for {
+		conn, err := l.Accept()
+		if err == nil {
+			go ra.handleConnection(conn)
+		}
+	}
+}

application/contactmanagerinterface.go

@@ -0,0 +1,11 @@
+package application
+
+import (
+	"crypto/rsa"
+)
+
+// ContactManagerInterface provides a mechanism for autonous applications
+// to make decisions on what connections to accept or reject.
+type ContactManagerInterface interface {
+	LookupContact(hostname string, publicKey rsa.PublicKey) (allowed, known bool)
+}

application/examples/echobot/main.go

@@ -0,0 +1,31 @@
+package main
+
+import (
+	"github.com/s-rah/go-ricochet/application"
+	"github.com/s-rah/go-ricochet/utils"
+	"log"
+	"time"
+)
+
+func main() {
+	echobot := new(application.RicochetApplication)
+	pk, err := utils.LoadPrivateKeyFromFile("./testing/private_key")
+
+	if err != nil {
+		log.Fatalf("error reading private key file: %v", err)
+	}
+
+	l, err := application.SetupOnion("127.0.0.1:9051", "", pk, 9878)
+
+	if err != nil {
+		log.Fatalf("error setting up onion service: %v", err)
+	}
+
+	echobot.Init(pk, new(application.AcceptAllContactManager))
+	echobot.OnChatMessage(func(rai *application.RicochetApplicationInstance, id uint32, timestamp time.Time, message string) {
+		log.Printf("message from %v - %v", rai.RemoteHostname, message)
+		rai.SendChatMessage(message)
+	})
+	log.Printf("echobot listening on %s", l.Addr().String())
+	echobot.Run(l)
+}

application/ricochetonion.go

@@ -0,0 +1,25 @@
+package application
+
+import (
+	"crypto/rsa"
+	"github.com/yawning/bulb"
+	"net"
+)
+
+func SetupOnion(proxyServer string, authentication string, pk *rsa.PrivateKey, onionport uint16) (net.Listener, error) {
+	c, err := bulb.Dial("tcp4", proxyServer)
+	if err != nil {
+		return nil, err
+	}
+
+	if err := c.Authenticate(authentication); err != nil {
+		return nil, err
+	}
+
+	cfg := &bulb.NewOnionConfig{
+		DiscardPK:  true,
+		PrivateKey: pk,
+	}
+
+	return c.NewListener(cfg, onionport)
+}

channels/channel.go

@@ -12,6 +12,7 @@ const (
 
 // AuthChannelResult captures the result of an authentication flow
 type AuthChannelResult struct {
+	Hostname       string
 	Accepted       bool
 	IsKnownContact bool
 }

channels/contactrequestchannel.go

@@ -1,13 +1,19 @@
 package channels
 
 import (
-	"errors"
 	"github.com/golang/protobuf/proto"
 	"github.com/s-rah/go-ricochet/utils"
 	"github.com/s-rah/go-ricochet/wire/contact"
 	"github.com/s-rah/go-ricochet/wire/control"
 )
 
+// Defining Versions
+const (
+	InvalidContactNameError    = utils.Error("InvalidContactNameError")
+	InvalidContactMessageError = utils.Error("InvalidContactMessageError")
+	InvalidContactRequestError = utils.Error("InvalidContactRequestError")
+)
+
 // ContactRequestChannel implements the ChannelHandler interface for a channel of
 // type "im.ricochet.contact.request". The channel may be inbound or outbound.
 // a ContactRequestChannelHandler implementation to handle chat events.
@@ -73,12 +79,12 @@ func (crc *ContactRequestChannel) OpenInbound(channel *Channel, oc *Protocol_Dat
 
 			if len(contactRequest.GetNickname()) > int(Protocol_Data_ContactRequest.Limits_NicknameMaxCharacters) {
 				// Violation of the Protocol
-				return nil, errors.New("invalid nickname")
+				return nil, InvalidContactNameError
 			}
 
 			if len(contactRequest.GetMessageText()) > int(Protocol_Data_ContactRequest.Limits_MessageMaxCharacters) {
 				// Violation of the Protocol
-				return nil, errors.New("invalid message")
+				return nil, InvalidContactMessageError
 			}
 
 			result := crc.Handler.ContactRequest(contactRequest.GetNickname(), contactRequest.GetMessageText())
@@ -86,7 +92,7 @@ func (crc *ContactRequestChannel) OpenInbound(channel *Channel, oc *Protocol_Dat
 			return messageBuilder.ReplyToContactRequestOnResponse(channel.ID, result), nil
 		}
 	}
-	return nil, errors.New("could not parse contact request extension")
+	return nil, InvalidContactRequestError
 }
 
 // OpenOutbound is the first method called for an outbound channel request.

channels/hiddenserviceauthchannel.go

@@ -7,7 +7,6 @@ import (
 	"crypto/rsa"
 	"crypto/sha256"
 	"encoding/asn1"
-	"errors"
 	"github.com/golang/protobuf/proto"
 	"github.com/s-rah/go-ricochet/utils"
 	"github.com/s-rah/go-ricochet/wire/auth"
@@ -15,6 +14,10 @@ import (
 	"io"
 )
 
+const (
+	InvalidClientCookieError = utils.Error("InvalidClientCookieError")
+)
+
 // HiddenServiceAuthChannel wraps implementation of im.ricochet.auth.hidden-service"
 type HiddenServiceAuthChannel struct {
 	// Methods of Handler are called for events on this channel
@@ -83,7 +86,7 @@ func (ah *HiddenServiceAuthChannel) OpenInbound(channel *Channel, oc *Protocol_D
 	clientCookie, _ := proto.GetExtension(oc, Protocol_Data_AuthHiddenService.E_ClientCookie)
 	if len(clientCookie.([]byte)[:]) != 16 {
 		// reutrn without opening channel.
-		return nil, errors.New("invalid client cookie")
+		return nil, InvalidClientCookieError
 	}
 	ah.AddClientCookie(clientCookie.([]byte)[:])
 	messageBuilder := new(utils.MessageBuilder)
@@ -101,7 +104,6 @@ func (ah *HiddenServiceAuthChannel) OpenOutbound(channel *Channel) ([]byte, erro
 		return nil, utils.PrivateKeyNotSetError
 	}
 
-
 	ah.channel = channel
 	messageBuilder := new(utils.MessageBuilder)
 	return messageBuilder.OpenAuthenticationChannel(ah.channel.ID, ah.GenClientCookie()), nil

connection/autoconnectionhandler.go

@@ -65,7 +65,7 @@ func (ach *AutoConnectionHandler) ClientAuthResult(accepted bool, isKnownContact
 func (ach *AutoConnectionHandler) ServerAuthValid(hostname string, publicKey rsa.PublicKey) (allowed, known bool) {
 	// Do something
 	accepted, isKnownContact := ach.sach(hostname, publicKey)
-	ach.authResultChannel <- channels.AuthChannelResult{Accepted: accepted, IsKnownContact: isKnownContact}
+	ach.authResultChannel <- channels.AuthChannelResult{Hostname: hostname, Accepted: accepted, IsKnownContact: isKnownContact}
 	return accepted, isKnownContact
 }
 

connection/channelmanager.go

@@ -1,8 +1,8 @@
 package connection
 
 import (
-	"errors"
 	"github.com/s-rah/go-ricochet/channels"
+	"github.com/s-rah/go-ricochet/utils"
 )
 
 // ChannelManager encapsulates the logic for server and client side assignment
@@ -38,7 +38,7 @@ func NewServerChannelManager() *ChannelManager {
 func (cm *ChannelManager) OpenChannelRequest(chandler channels.Handler) (*channels.Channel, error) {
 	// Some channels only allow us to open one of them per connection
 	if chandler.Singleton() && cm.Channel(chandler.Type(), channels.Outbound) != nil {
-		return nil, errors.New("Connection already has channel of type " + chandler.Type())
+		return nil, utils.AttemptToOpenMoreThanOneSingletonChannelError
 	}
 
 	channel := new(channels.Channel)
@@ -57,20 +57,20 @@ func (cm *ChannelManager) OpenChannelRequest(chandler channels.Handler) (*channe
 func (cm *ChannelManager) OpenChannelRequestFromPeer(channelID int32, chandler channels.Handler) (*channels.Channel, error) {
 	if cm.isClient && (channelID%2) != 0 {
 		// Server is trying to open odd numbered channels
-		return nil, errors.New("server may only open even numbered channels")
+		return nil, utils.ServerAttemptedToOpenEvenNumberedChannelError
 	} else if !cm.isClient && (channelID%2) == 0 {
 		// Server is trying to open odd numbered channels
-		return nil, errors.New("client may only open odd numbered channels")
+		return nil, utils.ClientAttemptedToOpenOddNumberedChannelError
 	}
 
 	_, exists := cm.channels[channelID]
 	if exists {
-		return nil, errors.New("channel id is already in use")
+		return nil, utils.ChannelIDIsAlreadyInUseError
 	}
 
 	// Some channels only allow us to open one of them per connection
 	if chandler.Singleton() && cm.Channel(chandler.Type(), channels.Inbound) != nil {
-		return nil, errors.New("Connection already has channel of type " + chandler.Type())
+		return nil, utils.AttemptToOpenMoreThanOneSingletonChannelError
 	}
 
 	channel := new(channels.Channel)

connection/connection.go

@@ -2,14 +2,13 @@ package connection
 
 import (
 	"errors"
+	"fmt"
 	"github.com/golang/protobuf/proto"
 	"github.com/s-rah/go-ricochet/channels"
 	"github.com/s-rah/go-ricochet/utils"
 	"github.com/s-rah/go-ricochet/wire/control"
 	"io"
 	"log"
-	"time"
-	"fmt"
 )
 
 // Connection encapsulates the state required to maintain a connection to
@@ -116,7 +115,7 @@ func (rc *Connection) RequestOpenChannel(ctype string, handler Handler) error {
 		chandler, err := handler.OnOpenChannelRequest(ctype)
 
 		if err != nil {
-		        rc.traceLog(fmt.Sprintf("failed to reqeust open channel of type %v", err))
+			rc.traceLog(fmt.Sprintf("failed to request open channel of type %v", err))
 			return err
 		}
 
@@ -125,7 +124,7 @@ func (rc *Connection) RequestOpenChannel(ctype string, handler Handler) error {
 			// Enforce Authentication Check.
 			_, authed := rc.Authentication[chandler.RequiresAuthentication()]
 			if !authed {
-				return errors.New("connection is not auth'd")
+				return utils.UnauthorizedActionError
 			}
 		}
 
@@ -174,7 +173,6 @@ func (rc *Connection) Process(handler Handler) error {
 	for !breaked {
 
 		var packet utils.RicochetData
-		tick := time.Tick(30 * time.Second)
 		select {
 		case <-rc.unlockChannel:
 			<-rc.unlockResponseChannel
@@ -189,12 +187,8 @@ func (rc *Connection) Process(handler Handler) error {
 			rc.Conn.Close()
 			handler.OnClosed(err)
 			return err
-		case <-tick:
-			rc.traceLog("peer timed out")
-			return errors.New("peer timed out")
 		}
 
-		
 		if packet.Channel == 0 {
 			rc.traceLog(fmt.Sprintf("received control packet on channel %d", packet.Channel))
 			res := new(Protocol_Data_Control.Packet)
@@ -209,7 +203,7 @@ func (rc *Connection) Process(handler Handler) error {
 				if len(packet.Data) == 0 {
 					rc.traceLog(fmt.Sprintf("removing channel %d", packet.Channel))
 					rc.channelManager.RemoveChannel(packet.Channel)
-					(*channel.Handler).Closed(errors.New("channel closed by peer"))
+					(*channel.Handler).Closed(utils.ChannelClosedByPeerError)
 				} else {
 					rc.traceLog(fmt.Sprintf("received packet on %v channel %d", (*channel.Handler).Type(), packet.Channel))
 					// Send The Ricochet Packet to the Handler

connection/inboundconnectionhandler.go

@@ -56,6 +56,7 @@ func (ich *InboundConnectionHandler) ProcessAuthAsServer(privateKey *rsa.Private
 
 	if err == nil {
 		if authResult.Accepted == true {
+			ich.connection.RemoteHostname = authResult.Hostname
 			return nil
 		}
 		return utils.ClientFailedToAuthenticateError

connection/outboundconnectionhandler.go

@@ -2,10 +2,9 @@ package connection
 
 import (
 	"crypto/rsa"
-	"errors"
 	"github.com/s-rah/go-ricochet/channels"
-	"github.com/s-rah/go-ricochet/utils"
 	"github.com/s-rah/go-ricochet/policies"
+	"github.com/s-rah/go-ricochet/utils"
 )
 
 // OutboundConnectionHandler is a convieniance wrapper for handling outbound
@@ -61,5 +60,5 @@ func (och *OutboundConnectionHandler) ProcessAuthAsClient(privateKey *rsa.Privat
 			return result.IsKnownContact, nil
 		}
 	}
-	return false, errors.New("authentication was not accepted by the server")
+	return false, utils.ServerRejectedClientConnectionError
 }

ricochet.go

@@ -1,11 +1,12 @@
 package goricochet
 
 import (
-    "github.com/s-rah/go-ricochet/utils"
 	"github.com/s-rah/go-ricochet/connection"
+	"github.com/s-rah/go-ricochet/utils"
 	"io"
 	"net"
 )
+
 // Open establishes a protocol session on an established net.Conn, and returns a new
 // OpenConnection instance representing this connection. On error, the connection
 // will be closed. This function blocks until version negotiation has completed.
@@ -27,7 +28,6 @@ func Open(remoteHostname string) (*connection.Connection, error) {
 	return rc, nil
 }
 
-
 // negotiate version takes an open network connection and executes
 // the ricochet version negotiation procedure.
 func negotiateVersion(conn net.Conn, remoteHostname string) (*connection.Connection, error) {
@@ -44,11 +44,10 @@ func negotiateVersion(conn net.Conn, remoteHostname string) (*connection.Connect
 	if res[0] != 0x01 {
 		return nil, utils.VersionNegotiationFailed
 	}
-    rc := connection.NewOutboundConnection(conn,remoteHostname)
+	rc := connection.NewOutboundConnection(conn, remoteHostname)
 	return rc, nil
 }
 
-
 // NegotiateVersionInbound takes in a connection and performs version negotiation
 // as if that connection was a client. Returns a ricochet connection if successful
 // error otherwise.
@@ -89,6 +88,3 @@ func NegotiateVersionInbound(conn net.Conn) (*connection.Connection, error) {
 	rc := connection.NewInboundConnection(conn)
 	return rc, nil
 }
-
-
-

ricochet_test.go

@@ -1,18 +1,17 @@
 package goricochet
 
 import (
-  "testing"
 	"github.com/s-rah/go-ricochet/utils"
 	"net"
+	"testing"
 	"time"
 )
 
-
 func SimpleServer() {
-    ln,_ := net.Listen("tcp", "127.0.0.1:11000")
-    conn,_ := ln.Accept()
+	ln, _ := net.Listen("tcp", "127.0.0.1:11000")
+	conn, _ := ln.Accept()
 	b := make([]byte, 4)
-    n,err := conn.Read(b)
+	n, err := conn.Read(b)
 	if n == 4 && err == nil {
 		conn.Write([]byte{0x01})
 	}
@@ -20,16 +19,16 @@ func SimpleServer() {
 }
 
 func BadVersionNegotiation() {
-    ln,_ := net.Listen("tcp", "127.0.0.1:11001")
-    conn,_ := ln.Accept()
+	ln, _ := net.Listen("tcp", "127.0.0.1:11001")
+	conn, _ := ln.Accept()
 	// We are already testing negotiation bytes, we don't care, just send a termination.
 	conn.Write([]byte{0x00})
 	conn.Close()
 }
 
 func NotRicochetServer() {
-    ln,_ := net.Listen("tcp", "127.0.0.1:11002")
-    conn,_ := ln.Accept()
+	ln, _ := net.Listen("tcp", "127.0.0.1:11002")
+	conn, _ := ln.Accept()
 	conn.Close()
 }
 
@@ -38,7 +37,7 @@ func TestRicochet(t *testing.T) {
 	// Wait for Server to Initialize
 	time.Sleep(time.Second)
 
-    rc,err := Open("127.0.0.1:11000|abcdefghijklmno.onion")
+	rc, err := Open("127.0.0.1:11000|abcdefghijklmno.onion")
 	if err == nil {
 		if rc.IsInbound {
 			t.Errorf("RicochetConnection declares itself as an Inbound connection after an Outbound attempt...that shouldn't happen")
@@ -48,22 +47,21 @@ func TestRicochet(t *testing.T) {
 	t.Errorf("RicochetProtocol: Open Failed: %v", err)
 }
 
-func TestBadVersionNegotiation(t*testing.T) {
+func TestBadVersionNegotiation(t *testing.T) {
 	go BadVersionNegotiation()
 	time.Sleep(time.Second)
 
-    _,err := Open("127.0.0.1:11001|abcdefghijklmno.onion")
+	_, err := Open("127.0.0.1:11001|abcdefghijklmno.onion")
 	if err != utils.VersionNegotiationFailed {
 		t.Errorf("RicochetProtocol: Server Had No Correct Version - Should Have Failed: err = %v", err)
 	}
 }
 
-
-func TestNotARicochetServer(t*testing.T) {
+func TestNotARicochetServer(t *testing.T) {
 	go NotRicochetServer()
 	time.Sleep(time.Second)
 
-    _,err := Open("127.0.0.1:11002|abcdefghijklmno.onion")
+	_, err := Open("127.0.0.1:11002|abcdefghijklmno.onion")
 	if err != utils.VersionNegotiationError {
 		t.Errorf("RicochetProtocol: Server Had No Correct Version - Should Have Failed: err = %v", err)
 	}

utils/crypto.go

@@ -4,10 +4,13 @@ import (
 	"crypto/rsa"
 	"crypto/x509"
 	"encoding/pem"
-	"errors"
 	"io/ioutil"
 )
 
+const (
+	InvalidPrivateKeyFileError = Error("InvalidPrivateKeyFileError")
+)
+
 // LoadPrivateKeyFromFile loads a private key from a file...
 func LoadPrivateKeyFromFile(filename string) (*rsa.PrivateKey, error) {
 	pemData, err := ioutil.ReadFile(filename)
@@ -18,7 +21,7 @@ func LoadPrivateKeyFromFile(filename string) (*rsa.PrivateKey, error) {
 
 	block, _ := pem.Decode(pemData)
 	if block == nil || block.Type != "RSA PRIVATE KEY" {
-		return nil, errors.New("not a private key")
+		return nil, InvalidPrivateKeyFileError
 	}
 
 	return x509.ParsePKCS1PrivateKey(block.Bytes)

utils/error.go

@@ -20,11 +20,24 @@ const (
 	UnknownChannelTypeError      = Error("UnknownChannelTypeError")
 	UnauthorizedChannelTypeError = Error("UnauthorizedChannelTypeError")
 
+	// Timeout Errors
 	ActionTimedOutError = Error("ActionTimedOutError")
+	PeerTimedOutError   = Error("PeerTimedOutError")
 
+	// Authentication Errors
 	ClientFailedToAuthenticateError     = Error("ClientFailedToAuthenticateError")
+	ServerRejectedClientConnectionError = Error("ServerRejectedClientConnectionError")
 
+	UnauthorizedActionError  = Error("UnauthorizedActionError")
+	ChannelClosedByPeerError = Error("ChannelClosedByPeerError")
 
+	// Channel Management Errors
+	ServerAttemptedToOpenEvenNumberedChannelError = Error("ServerAttemptedToOpenEvenNumberedChannelError")
+	ClientAttemptedToOpenOddNumberedChannelError  = Error("ClientAttemptedToOpenOddNumberedChannelError")
+	ChannelIDIsAlreadyInUseError                  = Error("ChannelIDIsAlreadyInUseError")
+	AttemptToOpenMoreThanOneSingletonChannelError = Error("AttemptToOpenMoreThanOneSingletonChannelError")
+
+	// Library Use Errors
 	PrivateKeyNotSetError = Error("ClientFailedToAuthenticateError")
 )
 

utils/networking.go

@@ -3,10 +3,14 @@ package utils
 import (
 	"bytes"
 	"encoding/binary"
-	"errors"
 	"io"
 )
 
+const (
+	InvalidPacketLengthError = Error("InvalidPacketLengthError")
+	InvalidChannelIDError    = Error("InvalidChannelIDError")
+)
+
 // RicochetData is a structure containing the raw data and the channel it the
 // message originated on.
 type RicochetData struct {
@@ -36,11 +40,11 @@ type RicochetNetwork struct {
 func (rn *RicochetNetwork) SendRicochetPacket(dst io.Writer, channel int32, data []byte) error {
 	packet := make([]byte, 4+len(data))
 	if len(packet) > 65535 {
-		return errors.New("packet too large")
+		return InvalidPacketLengthError
 	}
 	binary.BigEndian.PutUint16(packet[0:2], uint16(len(packet)))
 	if channel < 0 || channel > 65535 {
-		return errors.New("invalid channel ID")
+		return InvalidChannelIDError
 	}
 	binary.BigEndian.PutUint16(packet[2:4], uint16(channel))
 	copy(packet[4:], data[:])
@@ -68,7 +72,7 @@ func (rn *RicochetNetwork) RecvRicochetPacket(reader io.Reader) (RicochetData, e
 
 	size := int(binary.BigEndian.Uint16(header[0:2]))
 	if size < 4 {
-		return packet, errors.New("invalid packet length")
+		return packet, InvalidPacketLengthError
 	}
 
 	packet.Channel = int32(binary.BigEndian.Uint16(header[2:4]))

utils/networkresolver.go

@@ -1,12 +1,17 @@
 package utils
 
 import (
-	"errors"
 	"golang.org/x/net/proxy"
 	"net"
 	"strings"
 )
 
+const (
+	CannotResolveLocalTCPAddressError = Error("CannotResolveLocalTCPAddressError")
+	CannotDialLocalTCPAddressError    = Error("CannotDialLocalTCPAddressError")
+	CannotDialRicochetAddressError    = Error("CannotDialRicochetAddressError")
+)
+
 // NetworkResolver allows a client to resolve various hostnames to connections
 // The supported types are onions address are:
 //  * ricochet:jlq67qzo6s4yp3sp
@@ -21,11 +26,11 @@ func (nr *NetworkResolver) Resolve(hostname string) (net.Conn, string, error) {
 		addrParts := strings.Split(hostname, "|")
 		tcpAddr, err := net.ResolveTCPAddr("tcp", addrParts[0])
 		if err != nil {
-			return nil, "", errors.New("Cannot Resolve Local TCP Address")
+			return nil, "", CannotResolveLocalTCPAddressError
 		}
 		conn, err := net.DialTCP("tcp", nil, tcpAddr)
 		if err != nil {
-			return nil, "", errors.New("Cannot Dial Local TCP Address")
+			return nil, "", CannotDialLocalTCPAddressError
 		}
 
 		// return just the onion address, not the local override for the hostname
@@ -45,7 +50,7 @@ func (nr *NetworkResolver) Resolve(hostname string) (net.Conn, string, error) {
 
 	conn, err := torDialer.Dial("tcp", resolvedHostname+".onion:9878")
 	if err != nil {
-		return nil, "", errors.New("Cannot Dial Remote Ricochet Address")
+		return nil, "", CannotDialRicochetAddressError
 	}
 
 	return conn, resolvedHostname, nil