From 52236ef5225e636b3c072615b85f8a45271e29c3 Mon Sep 17 00:00:00 2001
From: Pavel Brychta <pavel.brychta@post.cz>
Date: Fri, 16 Jul 2021 09:56:43 +0200
Subject: [PATCH] Prvni odevzdani

---
 LICENSE           |  2 +-
 src/encString.cpp | 65 +++++++++++++++++++++++++++++++++++++++++++++++
 src/encString.hpp |  9 +++++++
 3 files changed, 75 insertions(+), 1 deletion(-)
 create mode 100644 src/encString.cpp
 create mode 100644 src/encString.hpp

diff --git a/LICENSE b/LICENSE
index 2071b23..d6c998d 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) <year> <copyright holders>
+Copyright (c) 2019-2021 xPablo.cz
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 
diff --git a/src/encString.cpp b/src/encString.cpp
new file mode 100644
index 0000000..3c117fd
--- /dev/null
+++ b/src/encString.cpp
@@ -0,0 +1,65 @@
+#include "encString.hpp"
+#include <WiFiConfig.h>
+#include <base64.h>
+#include <libb64/cdecode.h>
+
+#if defined(ESP8266)
+# define ESP_getChipId() (ESP.getChipId())
+#else
+# include <esp_wifi.h>
+# define ESP_getChipId() ((uint32_t)ESP.getEfuseMac())
+#endif
+
+void strEncode(String &str)
+{
+
+    const char *src = &str[0];
+    uint8_t key[4];
+    unsigned int enciphidx = 0;
+    char c;
+    unsigned int i;
+    uint32_t cid = ESP_getChipId();
+    uint32_t *pkey = (uint32_t *)&key[0];
+    uint8_t data[str.length()];
+
+    *pkey = cid;
+    for (i = 0; i < str.length(); i++) {
+        c = src[i];
+        c ^= key[enciphidx];
+        ++enciphidx;
+        enciphidx %= sizeof(key);
+        data[i] = c;
+    }
+#if defined(ESP8266)
+    str = base64::encode(data, str.length(), false);
+#else
+    str = base64::encode(data, str.length());
+#endif
+}
+
+void strDecode(String &str)
+{
+
+    const char *src = &str[0];
+    uint8_t key[4];
+    unsigned int enciphidx = 0;
+    unsigned int i;
+    uint8_t b;
+    uint32_t cid = ESP_getChipId();
+    uint32_t *pkey = (uint32_t *)&key[0];
+    uint8_t data[str.length()];
+    unsigned int clen = base64_decode_chars(src, str.length(), (char *)data);
+    String result = F("");
+
+    if (0 != clen) {
+        *pkey = cid;
+        for (i = 0; i < clen; i++) {
+            b = data[i];
+            b ^= key[enciphidx];
+            ++enciphidx;
+            enciphidx %= sizeof(key);
+            result.concat(char(b));
+        }
+    }
+    str = result;
+}
diff --git a/src/encString.hpp b/src/encString.hpp
new file mode 100644
index 0000000..b794665
--- /dev/null
+++ b/src/encString.hpp
@@ -0,0 +1,9 @@
+#ifndef _ENCSTRING_HPP_
+#define _ENCSTRING_HPP_
+#include <Arduino.h>
+
+void strEncode(String &str);
+
+void strDecode(String &str);
+
+#endif