Encryption and decryption issue

[xswxm]

Hi, bro, i used your lib to encrypt a msg first and then decrypt it, finding that part of the msg are not decrypted correctly.

Output:

Booting...
Let's encrypt:
 IV b64: MDAwMDAwMDAwMDAwMDAwMA==
 Message: {"data":{"value":300}, "SEQN":700 , "msg":"IT WORKS!!" }
 Message in B64: eyJkYXRhIjp7InZhbHVlIjozMDB9LCAiU0VRTiI6NzAwICwgIm1zZyI6IklUIFdPUktTISEiIH0=
 The lenght is:  76
Encryption done!
Cipher size: 80
Encrypted data in base64: Jdq1ko6TKPewmlSdn3zTaEP2yGWw10UXdansMHHuYbZdSDFWWH5cTq6LZO5Qey1JuY2ppygYicILzp8haWSS75oigJSZZo9uPXxuTwEO2mQ=
Done...
 Plain in B64: 蟢��6D&.HxP�<bHVlIjozMDB9LCAiU0VRTiI6NzAwICwgIm1zZyI6IklUIFdPUktTISEiIH0
 Plain size: 80
 Decrypted data in base64: 﨩����悄�縧ue":300}, "SEQN":700 , "msg":"IT WORKS!!" }���

Code:

#include "AES.h"
#include "base64.h"

AES aes;

void setup() {
  Serial.begin(115200);
  Serial.println("\nBooting...");

  char b64data[200];
  byte cipher[1000];
  byte iv [N_BLOCK] ;

  Serial.println("Let's encrypt:");
  // Our AES key. Note that is the same that is used on the Node-Js side but as hex bytes.
  byte key[] = { 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30 };

  // The unitialized Initialization vector
  //byte my_iv[N_BLOCK] = { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
  byte my_iv[N_BLOCK] = { 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30 };

  // Our message to encrypt. Static for this example.
  String msg = "{\"data\":{\"value\":300}, \"SEQN\":700 , \"msg\":\"IT WORKS!!\" }";

  aes.set_key( key , sizeof(key));  // Get the globally defined key

  // Print the IV
  base64_encode( b64data, (char *)my_iv, N_BLOCK);
  Serial.println(" IV b64: " + String(b64data));

  Serial.println(" Message: " + msg );

  int b64len = base64_encode(b64data, (char *)msg.c_str(), msg.length());
  Serial.println (" Message in B64: " + String(b64data) );
  Serial.println (" The lenght is:  " + String(b64len) );

  // For sanity check purpose
  //base64_decode( decoded , b64data , b64len );
  //Serial.println("Decoded: " + String(decoded));

  // Encrypt! With AES128, our key and IV, CBC and pkcs7 padding
  aes.do_aes_encrypt((byte *)b64data, b64len , cipher, key, 128, my_iv);

  Serial.println("Encryption done!");

  Serial.println("Cipher size: " + String(aes.get_size()));

  b64len = base64_encode(b64data, (char *)cipher, aes.get_size() );
  Serial.println ("Encrypted data in base64: " + String(b64data) );

  Serial.println("Done...");

  byte plain[1000];
  b64len = base64_decode(b64data, b64data, b64len);
  aes.do_aes_decrypt((byte *)b64data, b64len, plain, key, 128, my_iv);
  
  base64_decode(b64data, (char *)plain, aes.get_size());
  Serial.println (" Plain in B64: " + String((char *)plain) );
  Serial.println(" Plain size: " + String(aes.get_size()));
  Serial.println (" Decrypted data in base64: " + String(b64data) );
}

void loop() {
  // put your main code here, to run repeatedly:
}

[kakopappa]

Yah sorry decrypt is broken

On Thu, Mar 23, 2017 at 8:42 PM Adon [email protected] wrote:

Hi, bro, i used your lib to encrypt a msg first and then decrypt it, finding that part of the msg are not decrypted correctly.

Output:

Booting... Let's encrypt: IV b64: MDAwMDAwMDAwMDAwMDAwMA== Message: {"data":{"value":300}, "SEQN":700 , "msg":"IT WORKS!!" } Message in B64: eyJkYXRhIjp7InZhbHVlIjozMDB9LCAiU0VRTiI6NzAwICwgIm1zZyI6IklUIFdPUktTISEiIH0= The lenght is: 76 Encryption done! Cipher size: 80 Encrypted data in base64: Jdq1ko6TKPewmlSdn3zTaEP2yGWw10UXdansMHHuYbZdSDFWWH5cTq6LZO5Qey1JuY2ppygYicILzp8haWSS75oigJSZZo9uPXxuTwEO2mQ= Done... Plain in B64: 蟢���6D&.HxP�<bHVlIjozMDB9LCAiU0VRTiI6NzAwICwgIm1zZyI6IklUIFdPUktTISEiIH0����� Plain size: 80 Decrypted data in base64: 﨩�����悄�縧ue":300}, "SEQN":700 , "msg":"IT WORKS!!" }���

Code:

#include "AES.h" #include "base64.h"

AES aes;

void setup() { Serial.begin(115200); Serial.println("\nBooting...");

char b64data[200]; byte cipher[1000]; byte iv [N_BLOCK] ;

Serial.println("Let's encrypt:"); // Our AES key. Note that is the same that is used on the Node-Js side but as hex bytes. byte key[] = { 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30 };

// The unitialized Initialization vector //byte my_iv[N_BLOCK] = { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; byte my_iv[N_BLOCK] = { 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30 };

// Our message to encrypt. Static for this example. String msg = "{"data":{"value":300}, "SEQN":700 , "msg":"IT WORKS!!" }";

aes.set_key( key , sizeof(key)); // Get the globally defined key

// Print the IV base64_encode( b64data, (char *)my_iv, N_BLOCK); Serial.println(" IV b64: " + String(b64data));

Serial.println(" Message: " + msg );

int b64len = base64_encode(b64data, (char *)msg.c_str(), msg.length()); Serial.println (" Message in B64: " + String(b64data) ); Serial.println (" The lenght is: " + String(b64len) );

// For sanity check purpose //base64_decode( decoded , b64data , b64len ); //Serial.println("Decoded: " + String(decoded));

// Encrypt! With AES128, our key and IV, CBC and pkcs7 padding aes.do_aes_encrypt((byte *)b64data, b64len , cipher, key, 128, my_iv);

Serial.println("Encryption done!");

Serial.println("Cipher size: " + String(aes.get_size()));

b64len = base64_encode(b64data, (char *)cipher, aes.get_size() ); Serial.println ("Encrypted data in base64: " + String(b64data) );

Serial.println("Done...");

byte plain[1000]; b64len = base64_decode(b64data, b64data, b64len); aes.do_aes_decrypt((byte *)b64data, b64len, plain, key, 128, my_iv);

base64_decode(b64data, (char *)plain, aes.get_size()); Serial.println (" Plain in B64: " + String((char *)plain) ); Serial.println(" Plain size: " + String(aes.get_size())); Serial.println (" Decrypted data in base64: " + String(b64data) ); }

void loop() { // put your main code here, to run repeatedly: }

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[xswxm]

thanks PS: i also tried some other online aes encryption tools but return a different result.

[mtnbrit]

You need to base64 decode the IV.

Heres a working decoder lib

edit the AESLib.cpp file with this

String AESLib::decrypt(String msg, byte key[], String my_iv) {
  
  aes.set_key(key, sizeof(key));
  char data_decoded[200];
  char iv_decoded[200];
  byte out[200];
  char temp[200];
  msg.toCharArray(temp, 200);
  int b64len = base64_decode(data_decoded, temp, msg.length());
  my_iv.toCharArray(temp, 200);
  base64_decode(iv_decoded, temp, my_iv.length());
  aes.do_aes_decrypt((byte *)data_decoded, b64len, out, key, 128, (byte *)iv_decoded);
  
  char message[msg.length()];
  base64_decode(message, (char *)out, msg.length());
  return String(message);
}

and in AESLib.h

    String decrypt(String msg, byte key[], String my_iv);

and then call it with

String Msg = aesLib.decrypt(String(encmsg), key, String(my_iv));

[ofthesea-io]

Are you planning on fixing the decryption part?

[kakopappa]

did you try @mtnbrit decrypt code above?

[ofthesea-io]

I did, but it looks like there are still an issue with the width.

[ghost]

Hello, I am not able to put String AESLib :: decrypt (String msg, byte key [], String my_iv) {to work, this gives me this error: I would like to get a call because this lib and 5 * to use is missing even this

[ofthesea-io]

I would not use the String object. Rather use a char array buffer with enough width in it and then terminate it, where needed.

Edit:

Take a look at this lib and example.

https://github.com/intrbiz/arduino-crypto/issues/6

This should help

[JagadeeshRam]

'base64_encode' was not declared in this scope plzz help me out

Thanks