this is tuto1

token-validator/challenge.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"bytes"
 	"crypto/hmac"
 	"crypto/sha512"
 	"encoding/hex"
@@ -127,13 +128,35 @@ func challengePing(s *Student, t *givenToken, chid int) error {
 		expected = []byte("deadbeef")
 	}
 
+	// Allow 1 iteration or the 10 ones
+	var expected10 []byte
+	for i := 0; i < 10; i++ {
+		expected10 = append(expected10, expected...)
+	}
+
+	// Make it case insensitive
+	expectedC := bytes.ToUpper(expected)
+	expected10C := bytes.ToUpper(expected10)
+
 	pkey := s.GetPKey()
-	if expectedToken, err := GenerateToken(pkey, chid, expected); err != nil {
+	if expectedToken, err := GenerateToken(pkey, 0, expected); err != nil {
 		return err
-	} else if ! hmac.Equal(expectedToken, t.token) {
-		return errors.New("This is not the expected token.")
-	} else {
+	} else if hmac.Equal(expectedToken, t.token) {
 		return nil
+	} else if expectedToken, err := GenerateToken(pkey, 0, expectedC); err != nil {
+		return err
+	} else if hmac.Equal(expectedToken, t.token) {
+		return nil
+	} else if expectedToken, err := GenerateToken(pkey, 0, expected10); err != nil {
+		return err
+	} else if hmac.Equal(expectedToken, t.token) {
+		return nil
+	} else if expectedToken, err := GenerateToken(pkey, 0, expected10C); err != nil {
+		return err
+	} else if hmac.Equal(expectedToken, t.token) {
+		return nil
+	} else {
+		return errors.New("This is not the expected token.")
 	}
 }