hardened WiFi-String stuff

Software/include/eeprom.h

@@ -102,7 +102,6 @@ uint32_t Checksum_EEPROM(uint8_t const *data, size_t len);
 void dumpEEPROM(uint16_t memoryAddress, uint16_t length);
 void MovePersistencePage_EEPROM(boolean reset);
 uint32_t ConfigSanityCheck(bool autocorrect = false);
-bool validateWiFiString(char *string, size_t size);
 void writeSequentialToEEPROM(uint16_t memoryAddress, uint16_t length);
 void writeZeroToEEPROM(uint16_t memoryAddress, uint16_t length);
 

Software/include/globals.h

@@ -10,7 +10,7 @@ typedef struct Globals_s
   tSystem_Status resumeStatus = sysStat_Startup; /**< Status to resume after rain mode */
   char systemStatustxt[16] = "";                 /**< Text representation of system status */
   EERequest_t requestEEAction = EE_IDLE;         /**< EEPROM-related request */
-  char DeviceName[33];                           /**< Device name */
+  char DeviceName[25];                           /**< Device name */
   char DeviceNameId[sizeof(DeviceName) + 8];     /**< Device name plus 8 chars chipID */
   char FlashVersion[10];                         /**< Flash version */
   uint16_t eePersistanceAdress;                  /**< EEPROM persistence address */

Software/include/utilities.h

@@ -0,0 +1,36 @@
+#ifndef UTILITIES_H
+#define UTILITIES_H
+
+#include <Arduino.h>
+
+/**
+ * @brief Validates whether a given string contains only characters allowed in WiFi SSIDs and passwords.
+ *
+ * This function checks each character in the provided string to ensure
+ * that it contains only characters allowed in WiFi SSIDs and passwords.
+ * It considers characters from 'A' to 'Z', 'a' to 'z', '0' to '9', as well as
+ * the following special characters: ! " # $ % & ' ( ) * + , - . / : ; < = > ? @ [ \ ] ^ _ ` { | } ~
+ *
+ * @param string Pointer to the string to be validated.
+ * @param size Size of the string including the null-terminator.
+ * @return true if the string contains only allowed characters or is NULL,
+ *         false otherwise.
+ */
+bool validateWiFiString(char *string, size_t size);
+
+/**
+ * @brief Copies a string to a buffer, replacing invalid WiFi SSID characters with a placeholder.
+ *
+ * This function checks each character in the provided input string to ensure
+ * that it contains only characters allowed in WiFi SSIDs and passwords. If a character
+ * is invalid, it replaces it with a placeholder character (e.g., '_').
+ * It considers characters from 'A' to 'Z', 'a' to 'z', '0' to '9', as well as
+ * the following special characters: ! " # $ % & ' ( ) * + , - . / : ; < = > ? @ [ \ ] ^ _ ` { | } ~
+ *
+ * @param input Pointer to the input string to be validated and copied.
+ * @param buffer Pointer to the buffer where the output string will be copied.
+ * @param bufferSize Size of the buffer including the null-terminator.
+ */
+void sanitizeWiFiString(const char *input, char *buffer, size_t bufferSize);
+
+#endif // UTILITIES_H

Software/src/eeprom.cpp

@@ -9,6 +9,7 @@
 #include "eeprom.h"
 #include "debugger.h"
 #include "globals.h"
+#include "utilities.h"
 
 // Instance of I2C_eeprom for EEPROM access
 I2C_eeprom ee(I2C_EE_ADDRESS, EEPROM_SIZE_BYTES);
@@ -430,48 +431,6 @@ uint32_t ConfigSanityCheck(bool autocorrect)
   return setting_reset_bits;
 }
 
-/**
- * @brief Validates whether a given string contains only characters allowed in WiFi SSIDs and passwords.
- *
- * This function checks each character in the provided string to ensure
- * that it contains only characters allowed in WiFi SSIDs and passwords.
- * It considers characters from 'A' to 'Z', 'a' to 'z', '0' to '9', as well as
- * the following special characters: ! " # $ % & ' ( ) * + , - . / : ; < = > ? @ [ \ ] ^ _ ` { | } ~
- *
- * @param string Pointer to the string to be validated.
- * @param size Size of the string including the null-terminator.
- * @return true if the string contains only allowed characters or is NULL,
- *         false otherwise.
- */
-bool validateWiFiString(char *string, size_t size)
-{
-  if (string == NULL)
-    return false;
-
-  for (size_t i = 0; i < size; i++)
-  {
-    char c = string[i];
-    if (c == '\0')
-    {
-      // Reached the end of the string, all characters were valid WiFi characters.
-      return true;
-    }
-    if (!((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') ||
-          (c >= '0' && c <= '9') || c == '!' || c == '"' || c == '#' ||
-          c == '$' || c == '%' || c == '&' || c == '\'' || c == '(' ||
-          c == ')' || c == '*' || c == '+' || c == ',' || c == '-' ||
-          c == '.' || c == '/' || c == ':' || c == ';' || c == '<' ||
-          c == '=' || c == '>' || c == '?' || c == '@' || c == '[' ||
-          c == '\\' || c == ']' || c == '^' || c == '_' || c == '`' ||
-          c == '{' || c == '|' || c == '}' || c == '~'))
-    {
-      // Found a character that is not a valid WiFi character.
-      return false;
-    }
-  }
-  // If the loop completes without finding a null terminator, the string is invalid.
-  return false;
-}
 
 /**
  * @brief Write sequential numbers to a portion of EEPROM.

Software/src/main.cpp

@@ -19,6 +19,7 @@
 #include "globals.h"
 #include "dtc.h"
 #include "debugger.h"
+#include "utilities.h"
 #if defined(FEATURE_ENABLE_LORA) || defined(FEATURE_ENABLE_UARTLORA)
 #include "lora_net.h"
 #endif
@@ -571,6 +572,7 @@ void wifiMaintainConnectionTicker_callback()
  */
 void toggleWiFiAP(bool shutdown)
 {
+	char buffer[33];
 	// Check if WiFi is currently active
 	if (WiFi.getMode() != WIFI_OFF)
 	{
@@ -588,7 +590,8 @@ void toggleWiFiAP(bool shutdown)
 		// Start WiFi in Access Point (AP) mode
 		WiFi.mode(WIFI_AP);
 		WiFi.softAPConfig(IPAddress(WIFI_AP_IP_GW), IPAddress(WIFI_AP_IP_GW), IPAddress(255, 255, 255, 0));
-		WiFi.softAP(globals.DeviceNameId, QUOTE(WIFI_AP_PASSWORD));
+		sanitizeWiFiString(globals.DeviceNameId, buffer, sizeof(buffer));
+		WiFi.softAP(buffer, QUOTE(WIFI_AP_PASSWORD));
 
 		// Stop WiFi maintenance connection ticker if enabled and display debug messages
 #ifdef FEATURE_ENABLE_WIFI_CLIENT

Software/src/utilities.cpp

@@ -0,0 +1,94 @@
+#include "utilities.h"
+
+/**
+ * @brief Validates whether a given string contains only characters allowed in WiFi SSIDs and passwords.
+ *
+ * This function checks each character in the provided string to ensure
+ * that it contains only characters allowed in WiFi SSIDs and passwords.
+ * It considers characters from 'A' to 'Z', 'a' to 'z', '0' to '9', as well as
+ * the following special characters: ! " # $ % & ' ( ) * + , - . / : ; < = > ? @ [ \ ] ^ _ ` { | } ~
+ *
+ * @param string Pointer to the string to be validated.
+ * @param size Size of the string including the null-terminator.
+ * @return true if the string contains only allowed characters or is NULL,
+ *         false otherwise.
+ */
+bool validateWiFiString(char *string, size_t size)
+{
+    if (string == NULL)
+        return false;
+
+    for (size_t i = 0; i < size; i++)
+    {
+        char c = string[i];
+        if (c == '\0')
+        {
+            // Reached the end of the string, all characters were valid WiFi characters.
+            return true;
+        }
+        if (!((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') ||
+              (c >= '0' && c <= '9') || c == '!' || c == '"' || c == '#' ||
+              c == '$' || c == '%' || c == '&' || c == '\'' || c == '(' ||
+              c == ')' || c == '*' || c == '+' || c == ',' || c == '-' ||
+              c == '.' || c == '/' || c == ':' || c == ';' || c == '<' ||
+              c == '=' || c == '>' || c == '?' || c == '@' || c == '[' ||
+              c == '\\' || c == ']' || c == '^' || c == '_' || c == '`' ||
+              c == '{' || c == '|' || c == '}' || c == '~'))
+        {
+            // Found a character that is not a valid WiFi character.
+            return false;
+        }
+    }
+    // If the loop completes without finding a null terminator, the string is invalid.
+    return false;
+}
+
+/**
+ * @brief Copies a string to a buffer, replacing invalid WiFi SSID characters with a placeholder.
+ *
+ * This function checks each character in the provided input string to ensure
+ * that it contains only characters allowed in WiFi SSIDs and passwords. If a character
+ * is invalid, it replaces it with a placeholder character (e.g., '_').
+ * It considers characters from 'A' to 'Z', 'a' to 'z', '0' to '9', as well as
+ * the following special characters: ! " # $ % & ' ( ) * + , - . / : ; < = > ? @ [ \ ] ^ _ ` { | } ~
+ *
+ * @param input Pointer to the input string to be validated and copied.
+ * @param buffer Pointer to the buffer where the output string will be copied.
+ * @param bufferSize Size of the buffer including the null-terminator.
+ */
+void sanitizeWiFiString(const char *input, char *buffer, size_t bufferSize)
+{
+    if (input == NULL || buffer == NULL || bufferSize == 0)
+        return;
+
+    size_t i;
+    for (i = 0; i < bufferSize - 1; i++) // Leave space for null-terminator
+    {
+        char c = input[i];
+        if (c == '\0')
+        {
+            // Reached the end of the input string, terminate the buffer
+            buffer[i] = '\0';
+            return;
+        }
+        if (!((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') ||
+              (c >= '0' && c <= '9') || c == '!' || c == '"' || c == '#' ||
+              c == '$' || c == '%' || c == '&' || c == '\'' || c == '(' ||
+              c == ')' || c == '*' || c == '+' || c == ',' || c == '-' ||
+              c == '.' || c == '/' || c == ':' || c == ';' || c == '<' ||
+              c == '=' || c == '>' || c == '?' || c == '@' || c == '[' ||
+              c == '\\' || c == ']' || c == '^' || c == '_' || c == '`' ||
+              c == '{' || c == '|' || c == '}' || c == '~'))
+        {
+            // Replace invalid character with placeholder
+            buffer[i] = '_';
+        }
+        else
+        {
+            // Copy valid character to buffer
+            buffer[i] = c;
+        }
+    }
+    // Null-terminate the buffer
+    buffer[i] = '\0';
+}