From e0081ea8a8073d58c0d2b7069daad8d28ac3eb30 Mon Sep 17 00:00:00 2001
From: Zack Scholl <zack.scholl@gmail.com>
Date: Thu, 1 Nov 2018 07:26:18 -0700
Subject: [PATCH] tell user codephrase is wrong if PAKE fails

---
 src/cli/cli.go        |  8 +++++++-
 src/croc/recipient.go | 11 ++++++-----
 src/croc/sender.go    | 12 +++++++-----
 3 files changed, 20 insertions(+), 11 deletions(-)

diff --git a/src/cli/cli.go b/src/cli/cli.go
index d07ad95..2ee1c76 100644
--- a/src/cli/cli.go
+++ b/src/cli/cli.go
@@ -98,7 +98,7 @@ func Run() {
 		// if trying to send but forgot send, let the user know
 		if c.Args().First() != "" && utils.Exists(c.Args().First()) {
 			_, fname := filepath.Split(c.Args().First())
-			yn := utils.GetInput(fmt.Sprintf("Did you mean to send '%s'? (y/n)", fname))
+			yn := utils.GetInput(fmt.Sprintf("Did you mean to send '%s'? (y/n) ", fname))
 			if strings.ToLower(yn) == "y" {
 				return send(c)
 			}
@@ -204,6 +204,9 @@ func send(c *cli.Context) error {
 		cr.Codephrase,
 		cr.Codephrase,
 	)
+	if cr.Debug {
+		croc.SetDebugLevel("debug")
+	}
 	return cr.Send(fname, cr.Codephrase)
 }
 
@@ -226,6 +229,9 @@ func receive(c *cli.Context) error {
 	if cr.Codephrase == "" {
 		cr.Codephrase = utils.GetInput("Enter receive code: ")
 	}
+	if cr.Debug {
+		croc.SetDebugLevel("debug")
+	}
 	err := cr.Receive(cr.Codephrase)
 	if err == nil && openFolder {
 		cwd, _ := os.Getwd()
diff --git a/src/croc/recipient.go b/src/croc/recipient.go
index 162c9e6..5efeff7 100644
--- a/src/croc/recipient.go
+++ b/src/croc/recipient.go
@@ -178,13 +178,13 @@ func (cr *Croc) receive(forceSend int, serverAddress string, tcpPorts []string,
 			// Q receives u
 			log.Debugf("[%d] Q computes k, sends H(k), v back to P", step)
 			if err := Q.Update(message); err != nil {
-				return err
+				return fmt.Errorf("Recipient is using wrong code phrase.")
 			}
 
 			// Q has the session key now, but we will still check if its valid
 			sessionKey, err = Q.SessionKey()
 			if err != nil {
-				return err
+				return fmt.Errorf("Recipient is using wrong code phrase.")
 			}
 			log.Debugf("%x\n", sessionKey)
 
@@ -221,7 +221,8 @@ func (cr *Croc) receive(forceSend int, serverAddress string, tcpPorts []string,
 			log.Debugf("[%d] Q recieves H(k) from P", step)
 			// check if everything is still kosher with our computed session key
 			if err := Q.Update(message); err != nil {
-				return err
+				log.Debug(err)
+				return fmt.Errorf("Recipient is using wrong code phrase.")
 			}
 			c.WriteMessage(websocket.BinaryMessage, []byte("ready"))
 		case 3:
@@ -289,7 +290,7 @@ func (cr *Croc) receive(forceSend int, serverAddress string, tcpPorts []string,
 			)
 			if !noPrompt {
 				if "y" != utils.GetInput("ok? (y/N): ") {
-					fmt.Fprintf(os.Stderr, "cancelling request")
+					fmt.Fprintf(os.Stderr, "Cancelling request")
 					c.WriteMessage(websocket.BinaryMessage, []byte("no"))
 					return nil
 				}
@@ -302,7 +303,7 @@ func (cr *Croc) receive(forceSend int, serverAddress string, tcpPorts []string,
 						if cr.WindowRecipientAccept {
 							break
 						} else {
-							fmt.Fprintf(os.Stderr, "cancelling request")
+							fmt.Fprintf(os.Stderr, "Cancelling request")
 							c.WriteMessage(websocket.BinaryMessage, []byte("no"))
 							return nil
 						}
diff --git a/src/croc/sender.go b/src/croc/sender.go
index b6f4248..a7a618f 100644
--- a/src/croc/sender.go
+++ b/src/croc/sender.go
@@ -219,10 +219,12 @@ func (cr *Croc) send(forceSend int, serverAddress string, tcpPorts []string, isL
 		case 2:
 			// P recieves H(k),v from Q
 			log.Debugf("[%d] P computes k, H(k), sends H(k) to Q", step)
-			if err := P.Update(message); err != nil {
-				return err
-			}
+			err := P.Update(message)
 			c.WriteMessage(websocket.BinaryMessage, P.Bytes())
+			if err != nil {
+				return fmt.Errorf("Recipient is using wrong code phrase.")
+			}
+
 			sessionKey, _ = P.SessionKey()
 			// check(err)
 			log.Debugf("%x\n", sessionKey)
@@ -235,7 +237,7 @@ func (cr *Croc) send(forceSend int, serverAddress string, tcpPorts []string, isL
 		case 3:
 			log.Debugf("[%d] recipient declares readiness for file info", step)
 			if !bytes.HasPrefix(message, []byte("ready")) {
-				return errors.New("recipient refused file")
+				return errors.New("Recipient refused file")
 			}
 
 			err = <-fileReady // block until file is ready
@@ -393,7 +395,7 @@ func (cr *Croc) send(forceSend int, serverAddress string, tcpPorts []string, isL
 
 			log.Debugf("[%d] recipient declares readiness for file data", step)
 			if !bytes.HasPrefix(message, []byte("ready")) {
-				return errors.New("recipient refused file")
+				return errors.New("Recipient refused file")
 			}
 			cr.StateString = "Transfer in progress..."
 			fmt.Fprintf(os.Stderr, "\rSending (->%s)...\n", cr.OtherIP)