hardened WiFi-String stuff

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