Prvni odevzdani - netestovano!!!

src/encipheredEEPROMStrings.cpp

@@ -0,0 +1,84 @@
+#if defined(ESP8266)
+ extern "C" {
+ #include "user_interface.h"
+ }
+ #define ESP_getChipId() (ESP.getChipId())
+#else
+ #include <esp_wifi.h>
+ #define ESP_getChipId() ((uint32_t)ESP.getEfuseMac())
+#endif
+
+String EES_readString(unsigned int start, size_t maxlen)
+{
+  uint8_t key[4];
+  unsigned int enciphidx = 0;
+  String result;
+  unsigned int top = EEPROM.read(start);
+  unsigned int i;
+
+  result.reserve(maxlen);
+  uint32_t cid = ESP_getChipId();
+  uint32_t *pkey = (uint32_t *)&key[0];
+  *pkey = cid;
+  DEBUG_MSG("Key = %02X:%02X:%02X:%02X\r\n", key[0], key[1], key[2], key[3]);
+  if ((top > 0) && (top < (maxlen - 2)))
+  {
+    uint8_t b;
+    for (i = start + 1; i < + start + top + 1; ++i)
+    {
+      b = EEPROM.read(i);
+
+      b ^= key[enciphidx];
+      ++enciphidx;
+      enciphidx %= sizeof(key);
+
+      result.concat(char(b));
+    }
+    b = EEPROM.read(i) ^ key[enciphidx];
+    if (b != 0)
+    {
+      DEBUG_MSG("_readString error! (%s)\r\n", result.c_str());
+      result = F(""); // spatna ukoncovaci nula - neplatny retezec
+    }
+  }
+  return result;
+}
+
+bool EES_storeString(unsigned int start, size_t maxlen, String &string)
+{
+  uint8_t key[4];
+  unsigned int enciphidx = 0;
+  unsigned int si = 0;
+  unsigned int top;
+  char c;
+  bool result = false; // retezec nebyl ulozeny cely (nevesel s do bufferu)
+  unsigned int i;
+
+  if (string.length() > maxlen - 2)
+    top = maxlen - 2;
+  else
+  {
+    result = true; // retezec se do urceneho mista vejde
+    top = string.length();
+  }
+
+  uint32_t cid = ESP_getChipId();
+  uint32_t *pkey = (uint32_t *)&key[0];
+  *pkey = cid;
+  DEBUG_MSG("Key = %02X:%02X:%02X:%02X\r\n", key[0], key[1], key[2], key[3]);
+  EEPROM.write(start, (uint8_t)top); // ulozime delku retezce (pouzite pr kontrolu pri vycitani)
+  for (i = start + 1; i < start + top + 1; ++i)
+  {
+    c = string[si];
+    c ^= key[enciphidx];
+    ++enciphidx;
+    enciphidx %= sizeof(key);
+    EEPROM.write(i, c);
+    ++si;
+  }
+  c = 0 ^ key[enciphidx];
+  EEPROM.write(i, c); // ukoncovaci a kontrolni nula
+
+  return result;
+}
+

src/encipheredEEPROMStrings.h

@@ -0,0 +1,25 @@
+/* Knihovna pro ukladani a cteni retezcu do/z EEPROM.
+ * Retezce jsou ulozeny jednoduse sifrovane pomoci XOR sifry.
+ * @author Pavel Brychta http://www.xpabo.cz
+ */
+
+/**
+ * @brief      Cteni sifrovanych retezcu z EEPROM
+ *
+ * @param[in]  start   Pocatecni adresa retezce v EEPROM
+ * @param[in]  maxlen  Maximalni delka retezce
+ *
+ * @return     Vycteny a desifrovany retezec
+ */
+String EES_readString(unsigned int start, size_t maxlen);
+
+/**
+ * @brief      Zapis retezcu do EEPROM
+ *
+ * @param[in]  start   Pocatecni adresa retezce v EEPROM
+ * @param[in]  maxlen  Maximalni delka retezce
+ * @param      string  Ukladany retezec
+ *
+ * @return     Priznak, zda se zapis podaril
+ */
+bool EES_storeString(unsigned int start, size_t maxlen, String &string);