Update telnet server login #296

src/sys/svc/hasp_telnet.cpp

@@ -15,6 +15,9 @@
 
 #include "../../hasp/hasp_dispatch.h"
 
+#define IAC_SHOW_CHARACTERS "\xff\xfc\x01"
+#define IAC_HIDE_CHARACTERS "\xff\xfb\x01"
+
 #if defined(ARDUINO_ARCH_ESP32)
 #include <WiFi.h>
 WiFiClient telnetClient;
@@ -44,14 +47,42 @@ ConsoleInput* telnetConsole;
 
 void telnet_update_prompt()
 {
-    if(telnetConsole) telnetConsole->update();
+    if(telnetConsole) telnetConsole->update(__LINE__);
     bufferedTelnetClient.flush();
 }
 
+static inline void telnet_new_prompt(const char* prompt)
+{
+    if(!telnetConsole) return;
+
+    telnetClient.println(IAC_SHOW_CHARACTERS);
+    telnetConsole->setPrompt(prompt);
+    telnetConsole->clearLine(); // avoid leaking information, updates the prompt
+    telnet_update_prompt();
+}
+
+static inline void telnet_echo_on()
+{
+    telnetClient.print(IAC_SHOW_CHARACTERS);
+}
+
+static inline void telnet_password_prompt()
+{
+    telnetClient.print(IAC_SHOW_CHARACTERS D_PASSWORD " " IAC_HIDE_CHARACTERS);
+}
+
+static inline void telnet_username_prompt()
+{
+    telnetClient.print(IAC_SHOW_CHARACTERS D_USERNAME " ");
+}
+
 static void telnetClientDisconnect()
 {
     if(telnetClient.connected())
         LOG_TRACE(TAG_TELN, F(D_TELNET_CLOSING_CONNECTION), telnetClient.remoteIP().toString().c_str());
+    bufferedTelnetClient.flush(); // empty buffer
+    telnetClient.flush();         // empty buffer
+
     Log.unregisterOutput(1); // telnetClient
     telnetClient.stop();
 
@@ -70,21 +101,25 @@ void telnetStop(void)
 
 void telnetClientLogon()
 {
-    telnetClient.println();
     debugPrintHaspHeader(&bufferedTelnetClient);
     telnetLoginState   = TELNET_AUTHENTICATED; // User and Pass are correct
     telnetLoginAttempt = 0;                    // Reset attempt counter
+                                               // telnetClient.setTimeout(10);
 
-    /* Now register logger for telnet */
+    // empty buffers
-    Log.registerOutput(1, &bufferedTelnetClient, LOG_LEVEL_VERBOSE, true);
     bufferedTelnetClient.flush();
-    // telnetClient.setTimeout(10);
+    telnet_new_prompt("Prompt > ");
+    telnetClient.flush();
 
+    /* Now register logger for telnet and switch to buffered stream */
+    Log.registerOutput(1, &bufferedTelnetClient, LOG_LEVEL_VERBOSE, true);
     LOG_TRACE(TAG_TELN, F(D_TELNET_CLIENT_LOGIN_FROM), telnetClient.remoteIP().toString().c_str());
 }
 
 void telnetAcceptClient()
 {
+    bufferedTelnetClient.flush(); // empty buffer
+
     if(telnetClient) {
         telnetClient.stop();     // previous client has disconnected
         Log.unregisterOutput(1); // telnetClient
@@ -96,6 +131,8 @@ void telnetAcceptClient()
     }
     LOG_INFO(TAG_TELN, F(D_TELNET_CLIENT_CONNECT_FROM), telnetClient.remoteIP().toString().c_str());
     telnetClient.setNoDelay(true);
+    telnetClient.printf("\x1b]2;%s\x07" TERM_CLEAR_LINE, haspDevice.get_hostname());
+    telnetClient.println("\r\nWelcome\r\n");
 
     /* Avoid a buffer here */
     // telnetClient.print((char)0xFF); // DO TERMINAL-TYPE
@@ -104,13 +141,16 @@ void telnetAcceptClient()
 
 #if HASP_USE_HTTP > 0 || HASP_USE_HTTP_ASYNC > 0
     if(strlen(http_config.username) != 0 || strlen(http_config.password) != 0) {
-        telnetClient.println(F("\r\n" D_USERNAME " "));
         telnetLoginState = TELNET_UNAUTHENTICATED;
+        telnetClient.println();
+        telnet_username_prompt();
     } else
 #endif
     {
         telnetClientLogon();
     }
+
+    telnetClient.flush();
     telnetLoginAttempt = 0; // Initial attempt
 }
 
@@ -202,30 +242,36 @@ static inline void telnetProcessCharacter(char ch)
 
 static void telnetProcessLine(const char* input)
 {
+    bufferedTelnetClient.flush();
+
     switch(telnetLoginState) {
         case TELNET_UNAUTHENTICATED: {
-            char buffer[20];
+
-            snprintf_P(buffer, sizeof(buffer), PSTR(D_PASSWORD " %c%c%c\n"), 0xFF, 0xFB,
-                       0x01); // Hide characters
-            telnetClient.print(buffer);
 #if HASP_USE_HTTP > 0 || HASP_USE_HTTP_ASYNC > 0
-            telnetLoginState = strcmp(input, http_config.username) == 0 ? TELNET_USERNAME_OK : TELNET_USERNAME_NOK;
+            bool username_is_valid = strcmp(input, http_config.username) == 0;
+            telnetLoginState       = username_is_valid ? TELNET_USERNAME_OK : TELNET_USERNAME_NOK;
+            telnet_password_prompt();
             break;
         }
         case TELNET_USERNAME_OK:
         case TELNET_USERNAME_NOK: {
-            telnetClient.printf(PSTR("%c%c%c\n"), 0xFF, 0xFC, 0x01); // Show characters
+            bool password_is_valid = strcmp(input, http_config.password) == 0;
-            if(telnetLoginState == TELNET_USERNAME_OK && strcmp(input, http_config.password) == 0) {
+            if(telnetConsole) telnetConsole->clearLine();
+            telnet_echo_on(); // Show characters
+
+            if(telnetLoginState == TELNET_USERNAME_OK && password_is_valid) {
                 telnetClientLogon();
             } else {
                 telnetLoginState = TELNET_UNAUTHENTICATED;
                 telnetLoginAttempt++; // Subsequent attempt
-                telnetClient.println(F(D_NETWORK_CONNECTION_UNAUTHORIZED "\r\n"));
                 LOG_WARNING(TAG_TELN, F(D_TELNET_INCORRECT_LOGIN_ATTEMPT), telnetClient.remoteIP().toString().c_str());
+
+                telnetClient.println(F(D_NETWORK_CONNECTION_UNAUTHORIZED));
+
                 if(telnetLoginAttempt >= 3) {
                     telnetClientDisconnect();
                 } else {
-                    telnetClient.print(F(D_USERNAME " "));
+                    telnetClient.println(F("\r\n\r\n" D_USERNAME " "));
                 }
             }
 #else
@@ -240,7 +286,7 @@ static void telnetProcessLine(const char* input)
             } else if(strcasecmp_P(input, PSTR("logoff")) == 0) {
 #if HASP_USE_HTTP > 0 || HASP_USE_HTTP_ASYNC > 0
                 if(strcmp(input, http_config.password) == 0) {
-                    telnetClient.println(F("\r\n" D_USERNAME " "));
+                    telnet_username_prompt();
                     telnetLoginState = TELNET_UNAUTHENTICATED;
                 } else
 #endif
@@ -251,6 +297,8 @@ static void telnetProcessLine(const char* input)
                 dispatch_text_line(input, TAG_TELN);
             }
     }
+
+    telnetClient.flush();
 }
 
 void telnetStart()