cleaning code and examples

README.md

@@ -1,11 +1,17 @@
-# THiNX AESLib (ESP32, ESP8266, Arduino)
+# THiNX AESLib (ESP32, ESP8266)
 
 [![Codacy Badge](https://api.codacy.com/project/badge/Grade/8dded023f3d14a69b3c38c9f5fd66a40)](https://www.codacy.com/app/suculent/thinx-aes-lib?utm_source=github.com&utm_medium=referral&utm_content=suculent/thinx-aes-lib&utm_campaign=Badge_Grade)
 
-An Arduino/ESP32/ESP8266 library to wrap AES encryption with Base64 support. This project is originally based on [AESLib by kakopappa](https://github.com/kakopappa/arduino-esp8266-aes-lib). This fork actually works, will be maintained at least for a while, and provides optimized methods that do not require using Arduino's flawed String objects (even though those are still in examples).
+An ESP32/ESP8266/Arduino library for Arduino IDE to wrap AES encryption with Base64 support. This project is originally based on [AESLib by kakopappa](https://github.com/kakopappa/arduino-esp8266-aes-lib). This fork actually works, will be maintained at least for a while, and provides optimized methods that do not require using Arduino's flawed String objects (even though those are still in examples).
+
+AESLib provides convenience methods for encrypting data to byte arrays and Strings, with optional additional base64 encoding to return strings instead of bare data.
 
 In future this should use AES implementation from BearSSL, when available (to save more RAM in larger projects).
 
+# Changes
+
+1.0.3 - fixed padding (after encoding, not before) 
+
 # Client Example
 
 ```
@@ -35,15 +41,15 @@ void aes_init() {
 String encrypt(char * msg, byte iv[]) {  
   int msgLen = strlen(msg);
   char encrypted[2 * msgLen];
-  aesLib.encrypt(msg, encrypted, aes_key, iv);  
+  aesLib.encrypt64(msg, encrypted, aes_key, iv);  
   return String(encrypted);
 }
 
 String decrypt(char * msg, byte iv[]) {
   unsigned long ms = micros();
   int msgLen = strlen(msg);
   char decrypted[msgLen]; // half may be enough
-  aesLib.decrypt(msg, decrypted, aes_key, iv);  
+  aesLib.decrypt64(msg, decrypted, aes_key, iv);  
   return String(decrypted);
 }
 

examples/base64_iv/base64_iv.ino

@@ -29,22 +29,23 @@ void aes_init() {
 
   // reset aes_iv to server-based value
   int ivLen = base64_decode((char*)server_b64iv.c_str(), (char *)aes_iv, server_b64iv.length());
-  Serial.printf("Decoded IV bytes: %i\n", ivLen);
+  Serial.print("Decoded IV bytes: ");
+  Serial.println(ivLen);
   print_key_iv();
 }
 
 String encrypt(char * msg, byte iv[]) {
   int msgLen = strlen(msg);
   char encrypted[2 * msgLen];
-  aesLib.encrypt(msg, encrypted, aes_key, iv);
+  aesLib.encrypt64(msg, encrypted, aes_key, iv);
   return String(encrypted);
 }
 
 String decrypt(char * msg, byte iv[]) {
   unsigned long ms = micros();
   int msgLen = strlen(msg);
   char decrypted[msgLen]; // half may be enough
-  aesLib.decrypt(msg, decrypted, aes_key, iv);
+  aesLib.decrypt64(msg, decrypted, aes_key, iv);
   return String(decrypted);
 }
 

examples/complex/complex.ino

@@ -14,7 +14,7 @@ AESLib aesLib;
 byte aes_key[] = { 0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30 };
 
 // General initialization vector (use your own)
-byte aes_iv[16] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; 
+byte aes_iv[16] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
 
 // Generate IV (once)
 void aes_init() {
@@ -80,7 +80,6 @@ String decode() {
   return String(decoded);
 }
 
-// V2
 String encrypt(char * msg, byte iv[]) {
   unsigned long ms = micros();
   int msgLen = strlen(msg);
@@ -92,7 +91,6 @@ String encrypt(char * msg, byte iv[]) {
   return String(encrypted);
 }
 
-// V2
 String decrypt(char * msg, byte iv[]) {
   unsigned long ms = micros();
   int msgLen = strlen(msg);
@@ -131,25 +129,21 @@ void loop() {
 
   loopcount++;
 
-  //sprintf(cleartext, "START; %i \n", loopcount);
   sprintf(cleartext, "AAAAAAAAA");
 
   print_key_iv();
 
   print_iv();
 
-  // V2
   Serial.println("ENCRYPTION (char*)");
   byte enc_iv[16] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; // iv_block gets written to, reqires always fresh copy.
   String encrypted = encrypt(cleartext, enc_iv);
   sprintf(ciphertext, "%s", encrypted.c_str());
-  //ciphertext = encrypted.c_str();
 
   Serial.print("Encrypted Result: ");
   Serial.println(encrypted);
   Serial.println();
 
-  // V2
   Serial.println("DECRYPTION (char*)");
   Serial.println(ciphertext);
   byte dec_iv[16] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; // iv_block gets written to, reqires always fresh copy.
@@ -160,7 +154,7 @@ void loop() {
 
   String plain = String(cleartext);
 
-  if (plain.indexOf(decrypted) == -1) { 
+  if (plain.indexOf(decrypted) == -1) {
     Serial.println("Decryption FAILED!");
     Serial.printf("At: %i \n", plain.indexOf(decrypted));
     delay(5000);

examples/simple/simple.ino

@@ -4,14 +4,14 @@
 
 AESLib aesLib;
 
-String plaintext = "AAAAAAAAA";
+String plaintext = "AAAAAAA";
 int loopcount = 0;
 
 char cleartext[256];
 char ciphertext[512];
 
 // AES Encryption Key
-byte aes_key[] = { 0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30 };
+byte aes_key[] = { 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30 };
 
 // General initialization vector (you must use your own IV's in production for full security!!!)
 byte aes_iv[N_BLOCK] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
@@ -20,15 +20,14 @@ byte aes_iv[N_BLOCK] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
 void aes_init() {
   aesLib.gen_iv(aes_iv);
   // workaround for incorrect B64 functionality on first run...
-  sprintf(cleartext, plaintext.c_str());
-  encrypt(cleartext, aes_iv);
+  encrypt("HELLO WORLD!", aes_iv);
 }
 
 String encrypt(char * msg, byte iv[]) {
   int msgLen = strlen(msg);
-  char encrypted[2 * msgLen];
+  char encrypted[4 * msgLen]; // AHA! needs to be large, 2x is not enough
   aesLib.encrypt64(msg, encrypted, aes_key, iv);
-  return String(encrypted); 
+  return String(encrypted);
 }
 
 String decrypt(char * msg, byte iv[]) {
@@ -41,15 +40,14 @@ String decrypt(char * msg, byte iv[]) {
 
 void setup() {
   Serial.begin(115200);
-
   aes_init();
 }
 
 void loop() {
 
   loopcount++;
 
-  sprintf(cleartext, plaintext.c_str());
+  sprintf(cleartext, "%s", plaintext.c_str());
 
   // Encrypt
   byte enc_iv[N_BLOCK] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; // iv_block gets written to, provide own fresh copy...

library.json

@@ -11,7 +11,7 @@
     "type": "git",
     "url": "https://github.com/suculent/thinx-aes-lib.git"
   },
-  "version": "1.0.0",
+  "version": "1.0.3",
   "frameworks": "arduino",
-  "platforms": ["esp8266", "esp32"]
+  "platforms": ["esp8266", "esp32", "avr"]
 }

library.properties

@@ -1,9 +1,9 @@
 name=AESLib
-version=1.0.0
+version=1.0.3
 author=Matej Sychra
 maintainer=Matej Sychra
 sentence=Arduino/ESP8266 wrapper for AES library with 128-bit CBC encryption
 paragraph=Arduino/ESP8266 wrapper for AES library with 128-bit CBC encryption
-category="Data Processing"
+category=Data Processing
 url=https://github.com/suculent/thinx-aes-lib
-architectures=esp8266,esp32
+architectures=*

src/AES.cpp

@@ -36,13 +36,13 @@
 /* This version derived by Mark Tillotson 2012-01-23, tidied up, slimmed down
    and tailored to 8-bit microcontroller abilities and Arduino datatypes.
 
-   The s-box and inverse s-box were retained as tables (0.5kB PROGMEM) but all 
-   the other transformations are coded to save table space.  Many efficiency 
+   The s-box and inverse s-box were retained as tables (0.5kB PROGMEM) but all
+   the other transformations are coded to save table space.  Many efficiency
    improvments to the routines mix_sub_columns() and inv_mix_sub_columns()
    (mainly common sub-expression elimination).
 
    Only the routines with precalculated subkey schedule are retained (together
-   with set_key() - this does however mean each AES object takes 240 bytes of 
+   with set_key() - this does however mean each AES object takes 240 bytes of
    RAM, alas)
 
    The CBC routines side-effect the iv argument (so that successive calls work
@@ -218,7 +218,7 @@ static void inv_mix_sub_columns (byte dt[N_BLOCK], byte st[N_BLOCK])
       byte a8 = f2(a4), b8 = f2(b4), c8 = f2(c4), d8 = f2(d4) ;
       byte a9 = a8 ^ a1,b9 = b8 ^ b1,c9 = c8 ^ c1,d9 = d8 ^ d1 ;
       byte ac = a8 ^ a4,bc = b8 ^ b4,cc = c8 ^ c4,dc = d8 ^ d4 ;
-      
+
       dt[i]         = is_box (ac^a2  ^  b9^b2  ^  cc^c1  ^  d9) ;
       dt[(i+5)&15]  = is_box (a9     ^  bc^b2  ^  c9^c2  ^  dc^d1) ;
       dt[(i+10)&15] = is_box (ac^a1  ^  b9     ^  cc^c2  ^  d9^d2) ;
@@ -232,21 +232,21 @@ AES::AES(){
   byte ar_iv[8] = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01 };
   memcpy(iv,ar_iv,8);
   memcpy(iv+8,ar_iv,8);
-  arr_pad[0] = 0x01;
-  arr_pad[1] = 0x02;
-  arr_pad[2] = 0x03;
-  arr_pad[3] = 0x04;
-  arr_pad[4] = 0x05;
-  arr_pad[5] = 0x06;
-  arr_pad[6] = 0x07;
-  arr_pad[7] = 0x08;
-  arr_pad[8] = 0x09;
-  arr_pad[9] = 0x0a;
-  arr_pad[10] = 0x0b;
-  arr_pad[11] = 0x0c;
-  arr_pad[12] = 0x0d;
-  arr_pad[13] = 0x0e;
-  arr_pad[14] = 0x0f;
+  arr_pad[0] = 0x00;
+  arr_pad[1] = 0x00;
+  arr_pad[2] = 0x00;
+  arr_pad[3] = 0x00;
+  arr_pad[4] = 0x00;
+  arr_pad[5] = 0x00;
+  arr_pad[6] = 0x00;
+  arr_pad[7] = 0x00;
+  arr_pad[8] = 0x00;
+  arr_pad[9] = 0x00;
+  arr_pad[10] = 0x00;
+  arr_pad[11] = 0x00;
+  arr_pad[12] = 0x00;
+  arr_pad[13] = 0x00;
+  arr_pad[14] = 0x00;
 }
 
 /******************************************************************************/
@@ -257,29 +257,29 @@ byte AES::set_key (byte key [], int keylen)
   switch (keylen)
     {
     case 16:
-    case 128: 
+    case 128:
       keylen = 16; // 10 rounds
       round = 10 ;
       break;
     case 24:
-    case 192: 
+    case 192:
       keylen = 24; // 12 rounds
       round = 12 ;
       break;
     case 32:
-    case 256: 
+    case 256:
       keylen = 32; // 14 rounds
       round = 14 ;
       break;
-    default: 
-      round = 0; 
+    default:
+      round = 0;
       return FAILURE;
     }
   hi = (round + 1) << 4 ;
   copy_n_bytes (key_sched, key, keylen) ;
   byte t[4] ;
   byte next = keylen ;
-  for (byte cc = keylen, rc = 1 ; cc < hi ; cc += N_COL) 
+  for (byte cc = keylen, rc = 1 ; cc < hi ; cc += N_COL)
     {
       for (byte i = 0 ; i < N_COL ; i++)
         t[i] = key_sched [cc-4+i] ;
@@ -340,7 +340,7 @@ byte AES::encrypt (byte plain [N_BLOCK], byte cipher [N_BLOCK])
       copy_and_key (s1, plain, (byte*) (key_sched)) ;
 
       for (r = 1 ; r < round ; r++)
-        {  
+        {
           byte s2 [N_BLOCK] ;
           mix_sub_columns (s2, s1) ;
           copy_and_key (s1, s2, (byte*) (key_sched + r * N_BLOCK)) ;
@@ -411,7 +411,7 @@ byte AES::decrypt (byte plain [N_BLOCK], byte cipher [N_BLOCK])
 /******************************************************************************/
 
 byte AES::cbc_decrypt (byte * cipher, byte * plain, int n_block, byte iv [N_BLOCK])
-{   
+{
   while (n_block--)
     {
       byte tmp [N_BLOCK] ;
@@ -429,7 +429,7 @@ byte AES::cbc_decrypt (byte * cipher, byte * plain, int n_block, byte iv [N_BLOC
 /******************************************************************************/
 
 byte AES::cbc_decrypt (byte * cipher, byte * plain, int n_block)
-{   
+{
   while (n_block--)
     {
       byte tmp [N_BLOCK] ;
@@ -505,7 +505,7 @@ void AES::padPlaintext(void* in,byte* out)
 /******************************************************************************/
 
 bool AES::CheckPad(byte* in,int lsize){
-  if (in[lsize-1] <= 0x0f){ 
+  if (in[lsize-1] <= 0x0f){
     int lpad = (int)in[lsize-1];
     for (int i = lsize - 1; i >= lsize-lpad; i--){
       if (arr_pad[lpad - 1] != in[i]){