Prevent Buffer Overflow and Added FlashStringHelper for text and binary (#26)

* Prevent buffer overflow on received data

* pass to 7 char to avoid save to flash by SDK

* return _contentLength, avoid array reparse to know len

* Added FlashStringHelper for text and binary

* Added FlashStringHelper also to AsyncWebSocketClient

* Added PROGMEM doc

* Corrected binary was sending PSTR as text, addded len

* Server calls client method and code as asked @me-no-dev

* server calls client method and code as asked by @me-no-dev

* Changed Code presentation

README.md

@@ -464,36 +464,48 @@ void onEvent(AsyncWebSocket * server, AsyncWebSocketClient * client, AwsEventTyp
 
 ### Methods for sending data to a socket client
 ```cpp
+
+
+
 //Server methods
 AsyncWebSocket ws("/ws");
 //printf to a client
-ws.printf([client id], [arguments...])
+ws.printf([client id], [arguments...]);
 //printf to all clients
-ws.printfAll([arguments...])
+ws.printfAll([arguments...]);
 //send text to a client
-ws.text([client id], [(char*)text])
+ws.text([client id], [(char*)text]);
-ws.text([client id], [text], [len])
+ws.text([client id], [text], [len]);
+const char flash_text[] PROGMEM = "Text to send"
+ws.text([client id], [PSTR("text")]);
+ws.text([client id], [FPSTR(flash_text)]);
 //send text to all clients
-ws.textAll([(char*text])
+ws.textAll([(char*text]);
-ws.textAll([text], [len])
+ws.textAll([text], [len]);
 //send binary to a client
-ws.binary([client id], [(char*)binary])
+ws.binary([client id], [(char*)binary]);
-ws.binary([client id], [binary], [len])
+ws.binary([client id], [binary], [len]);
+const uint8_t flash_binary[] PROGMEM = { 0x01, 0x02, 0x03, 0x04 };
+ws.binary([client id], [flash_binary], [len]);
 //send binary to all clients
-ws.binaryAll([(char*binary])
+ws.binaryAll([(char*binary]);
-ws.binaryAll([binary], [len])
+ws.binaryAll([binary], [len]);
 
 //client methods
 AsyncWebSocketClient * client;
 //printf to a client
-client->printf([arguments...])
+client->printf([arguments...]);
 //send text to a client
-client->text([(char*)text])
+client->text([(char*)text]);
-client->text([text], [len])
+client->text([text], [len]);
+const char flash_text[] PROGMEM = "Text to send";
+client->text([PSTR("text")]);
+client->text([FPSTR(flash_text)]);
 //send binary to a client
-client->binary([(char*)binary])
+client->binary([(char*)binary]);
-client->binary([binary], [len])
+client->binary([binary], [len]);
-
+const uint8_t flash_binary[] PROGMEM = { 0x01, 0x02, 0x03, 0x04 };
+client->binary([flash_binary], [len]);
 ```
 
 

examples/ESP32_AsyncFSBrowser/ESP32_AsyncFSBrowser.ino

@@ -125,18 +125,22 @@ void onEvent(AsyncWebSocket * server, AsyncWebSocketClient * client, AwsEventTyp
     os_printf("ws[%s][%u] pong[%u]: %s\n", server->url(), client->id(), len, (len)?(char*)data:"");
   } else if(type == WS_EVT_DATA){
     AwsFrameInfo * info = (AwsFrameInfo*)arg;
+    String msg = "";
     if(info->final && info->index == 0 && info->len == len){
       //the whole message is in a single frame and we got all of it's data
       os_printf("ws[%s][%u] %s-message[%llu]: ", server->url(), client->id(), (info->opcode == WS_TEXT)?"text":"binary", info->len);
       if(info->opcode == WS_TEXT){
-        data[len] = 0;
+        for(size_t i=0; i < info->len; i++) {
-        os_printf("%s\n", (char*)data);
+          msg += (char) data[i];
+        }
       } else {
-        for(size_t i=0; i < info->len; i++){
+        char buff[3];
-          os_printf("%02x ", data[i]);
+        for(size_t i=0; i < info->len; i++) {
+          sprintf(buff, "%02x ", (uint8_t) data[i]);
+          msg += buff ;
         }
-        os_printf("\n");
       }
+      os_printf("%s\n",msg.c_str());
       if(info->opcode == WS_TEXT)
         client->text("I got your text message");
       else
@@ -150,15 +154,19 @@ void onEvent(AsyncWebSocket * server, AsyncWebSocketClient * client, AwsEventTyp
       }
 
       os_printf("ws[%s][%u] frame[%u] %s[%llu - %llu]: ", server->url(), client->id(), info->num, (info->message_opcode == WS_TEXT)?"text":"binary", info->index, info->index + len);
-      if(info->message_opcode == WS_TEXT){
+      if(info->opcode == WS_TEXT){
-        data[len] = 0;
+        for(size_t i=0; i < info->len; i++) {
-        os_printf("%s\n", (char*)data);
+          msg += (char) data[i];
+        }
       } else {
-        for(size_t i=0; i < len; i++){
+        char buff[3];
-          os_printf("%02x ", data[i]);
+        for(size_t i=0; i < info->len; i++) {
+          sprintf(buff, "%02x ", (uint8_t) data[i]);
+          msg += buff ;
         }
-        os_printf("\n");
       }
+      os_printf("%s\n",msg.c_str());
+
 
       if((info->index + len) == info->len){
         os_printf("ws[%s][%u] frame[%u] end[%llu]\n", server->url(), client->id(), info->num, info->len);
@@ -174,8 +182,8 @@ void onEvent(AsyncWebSocket * server, AsyncWebSocketClient * client, AwsEventTyp
   }
 }
 
-const char* ssid = "**********";
+const char* ssid = "*******";
-const char* password = "************";
+const char* password = "*******";
 const char* http_username = "admin";
 const char* http_password = "admin";
 

examples/ESP_AsyncFSBrowser/ESP_AsyncFSBrowser.ino

@@ -128,18 +128,24 @@ void onEvent(AsyncWebSocket * server, AsyncWebSocketClient * client, AwsEventTyp
     os_printf("ws[%s][%u] pong[%u]: %s\n", server->url(), client->id(), len, (len)?(char*)data:"");
   } else if(type == WS_EVT_DATA){
     AwsFrameInfo * info = (AwsFrameInfo*)arg;
+    String msg = "";
     if(info->final && info->index == 0 && info->len == len){
       //the whole message is in a single frame and we got all of it's data
       os_printf("ws[%s][%u] %s-message[%llu]: ", server->url(), client->id(), (info->opcode == WS_TEXT)?"text":"binary", info->len);
+
       if(info->opcode == WS_TEXT){
-        data[len] = 0;
+        for(size_t i=0; i < info->len; i++) {
-        os_printf("%s\n", (char*)data);
+          msg += (char) data[i];
+        }
       } else {
-        for(size_t i=0; i < info->len; i++){
+        char buff[3];
-          os_printf("%02x ", data[i]);
+        for(size_t i=0; i < info->len; i++) {
+          sprintf(buff, "%02x ", (uint8_t) data[i]);
+          msg += buff ;
         }
-        os_printf("\n");
       }
+      os_printf("%s\n",msg.c_str());
+
       if(info->opcode == WS_TEXT)
         client->text("I got your text message");
       else
@@ -153,15 +159,19 @@ void onEvent(AsyncWebSocket * server, AsyncWebSocketClient * client, AwsEventTyp
       }
 
       os_printf("ws[%s][%u] frame[%u] %s[%llu - %llu]: ", server->url(), client->id(), info->num, (info->message_opcode == WS_TEXT)?"text":"binary", info->index, info->index + len);
-      if(info->message_opcode == WS_TEXT){
+  
-        data[len] = 0;
+      if(info->opcode == WS_TEXT){
-        os_printf("%s\n", (char*)data);
+        for(size_t i=0; i < info->len; i++) {
+          msg += (char) data[i];
+        }
       } else {
-        for(size_t i=0; i < len; i++){
+        char buff[3];
-          os_printf("%02x ", data[i]);
+        for(size_t i=0; i < info->len; i++) {
+          sprintf(buff, "%02x ", (uint8_t) data[i]);
+          msg += buff ;
         }
-        os_printf("\n");
       }
+      os_printf("%s\n",msg.c_str());
 
       if((info->index + len) == info->len){
         os_printf("ws[%s][%u] frame[%u] end[%llu]\n", server->url(), client->id(), info->num, info->len);
@@ -178,8 +188,8 @@ void onEvent(AsyncWebSocket * server, AsyncWebSocketClient * client, AwsEventTyp
 }
 
 
-const char* ssid = "**********";
+const char* ssid = "*******";
-const char* password = "************";
+const char* password = "*******";
 const char* http_username = "admin";
 const char* http_password = "admin";
 

src/AsyncJson.h

@@ -66,9 +66,10 @@ class AsyncJsonResponse: public AsyncAbstractResponse {
     ~AsyncJsonResponse() {}
     JsonVariant & getRoot() { return _root; }
     bool _sourceValid() { return _isValid; }
-    void setLength() {
+    size_t setLength() {
       _contentLength = _root.measureLength();
       if (_contentLength) { _isValid = true; }
+      return _contentLength; 
     }
 
     size_t _fillBuffer(uint8_t *data, size_t len){

src/AsyncWebSocket.cpp

@@ -504,6 +504,21 @@ void AsyncWebSocketClient::text(char * message){
 void AsyncWebSocketClient::text(String &message){
   text(message.c_str(), message.length());
 }
+void AsyncWebSocketClient::text(const __FlashStringHelper *data){
+  PGM_P p = reinterpret_cast<PGM_P>(data);
+  size_t n = 0;
+  while (1) {
+    if (pgm_read_byte(p+n) == 0) break;
+      n += 1;
+  }
+  char * message = (char*) malloc(n+1);
+  if(message){
+    for(size_t b=0; b<n; b++)
+      message[b] = pgm_read_byte(p++);
+    message[n] = 0;
+    text(message, n);
+  }
+}
 
 void AsyncWebSocketClient::binary(const char * message, size_t len){
   _queueMessage(new AsyncWebSocketBasicMessage(message, len, WS_BINARY));
@@ -520,6 +535,15 @@ void AsyncWebSocketClient::binary(char * message){
 void AsyncWebSocketClient::binary(String &message){
   binary(message.c_str(), message.length());
 }
+void AsyncWebSocketClient::binary(const __FlashStringHelper *data, size_t len){
+  PGM_P p = reinterpret_cast<PGM_P>(data);
+  char * message = (char*) malloc(len);
+  if(message){
+    for(size_t b=0; b<len; b++)
+      message[b] = pgm_read_byte(p++);
+    binary(message, len);
+  }
+}
 
 IPAddress AsyncWebSocketClient::remoteIP() {
     if(!_client) {
@@ -728,6 +752,11 @@ void AsyncWebSocket::text(uint32_t id, char * message){
 void AsyncWebSocket::text(uint32_t id, String &message){
   text(id, message.c_str(), message.length());
 }
+void AsyncWebSocket::text(uint32_t id, const __FlashStringHelper *message){
+  AsyncWebSocketClient * c = client(id);
+  if(c != NULL)
+    c->text(message);
+}
 void AsyncWebSocket::textAll(const char * message){
   textAll(message, strlen(message));
 }
@@ -740,6 +769,14 @@ void AsyncWebSocket::textAll(char * message){
 void AsyncWebSocket::textAll(String &message){
   textAll(message.c_str(), message.length());
 }
+void AsyncWebSocket::textAll(const __FlashStringHelper *message){
+  AsyncWebSocketClient * c = _clients;
+  while(c != NULL){
+    if(c->status() == WS_CONNECTED)
+      c->text(message);
+    c = c->next;
+  }
+}
 void AsyncWebSocket::binary(uint32_t id, const char * message){
   binary(id, message, strlen(message));
 }
@@ -752,6 +789,11 @@ void AsyncWebSocket::binary(uint32_t id, char * message){
 void AsyncWebSocket::binary(uint32_t id, String &message){
   binary(id, message.c_str(), message.length());
 }
+void AsyncWebSocket::binary(uint32_t id, const __FlashStringHelper *message, size_t len){
+  AsyncWebSocketClient * c = client(id);
+  if(c != NULL)
+    c-> binary(message, len);
+}
 void AsyncWebSocket::binaryAll(const char * message){
   binaryAll(message, strlen(message));
 }
@@ -764,6 +806,14 @@ void AsyncWebSocket::binaryAll(char * message){
 void AsyncWebSocket::binaryAll(String &message){
   binaryAll(message.c_str(), message.length());
 }
+void AsyncWebSocket::binaryAll(const __FlashStringHelper *message, size_t len){
+  AsyncWebSocketClient * c = _clients;
+  while(c != NULL){
+    if(c->status() == WS_CONNECTED)
+      c-> binary(message, len);
+    c = c->next;
+  }
+ }
 
 const char * WS_STR_CONNECTION = "Connection";
 const char * WS_STR_UPGRADE = "Upgrade";

src/AsyncWebSocket.h

@@ -106,12 +106,14 @@ class AsyncWebSocketClient {
     void text(uint8_t * message, size_t len);
     void text(char * message);
     void text(String &message);
+    void text(const __FlashStringHelper *data);
 
     void binary(const char * message, size_t len);
     void binary(const char * message);
     void binary(uint8_t * message, size_t len);
     void binary(char * message);
     void binary(String &message);
+    void binary(const __FlashStringHelper *data, size_t len);
 
     //system callbacks (do not call)
     void _onAck(size_t len, uint32_t time);
@@ -151,24 +153,28 @@ class AsyncWebSocket: public AsyncWebHandler {
     void text(uint32_t id, uint8_t * message, size_t len);
     void text(uint32_t id, char * message);
     void text(uint32_t id, String &message);
+    void text(uint32_t id, const __FlashStringHelper *message);
 
     void textAll(const char * message, size_t len);
     void textAll(const char * message);
     void textAll(uint8_t * message, size_t len);
     void textAll(char * message);
     void textAll(String &message);
+    void textAll(const __FlashStringHelper *message);
 
     void binary(uint32_t id, const char * message, size_t len);
     void binary(uint32_t id, const char * message);
     void binary(uint32_t id, uint8_t * message, size_t len);
     void binary(uint32_t id, char * message);
     void binary(uint32_t id, String &message);
+    void binary(uint32_t id, const __FlashStringHelper *message, size_t len);
 
     void binaryAll(const char * message, size_t len);
     void binaryAll(const char * message);
     void binaryAll(uint8_t * message, size_t len);
     void binaryAll(char * message);
     void binaryAll(String &message);
+    void binaryAll(const __FlashStringHelper *message, size_t len);
 
     void message(uint32_t id, AsyncWebSocketMessage *message);
     void messageAll(AsyncWebSocketMessage *message);