AES

Overview

Provides basic AES cryptographic operations, depends on AES Key Container.
For proper use, also check the documentation of AES Key container.

Encrypt

Is a static stateless function, uses AES Key Container as AES parameters.
Takes the buffer by reference and returns a new encrypted copy of the data.

AES::encrypt(AES::keyc &key_container, dutils::dbuffer &buffer)

• Parameters:
  • tancrypt::AES::keyc &key_container - AES key with preloaded credentials
  • dutils::dbuffer &buffer - Data to encrypt
• Returns:
  • dutils::dbuffer AES_DATA - Encrypted buffer

In case of a failure throws an exception.

Example

Hashed KeyRaw Key

#include <iostream>
#include "tancrypt/aes.hpp"

int main()
{
  // Makes life easier 
  using namespace tancrypt;

  // Data and key setup
  dutils::dbuffer payload("Hewwo, I am secret >.<");
  dutils::dbuffer my_keydata("Hewwo, I am key ^.^");

  // Setting up AES Key Container
  AES::keyc my_key(my_keydata, AES::Type::CBC256, hashAlg::SHA256);

  // Encrypting the data
  dutils::dbuffer encrypted_payload = AES::encrypt(my_key, payload);

  // You can check the results via helper function dutils::hexStr
  std::cout << "Original: " << payload.toStr() << std::endl; 
  std::cout << "Original(hex): " << dutils::hexStr(payload) << std::endl; 
  std::cout << "Encrypted: " << encrypted_payload.toStr() << std::endl;
  std::cout << "Encrypted(hex): " << dutils::hexStr(encrypted_payload) << std::endl;

  return 0;
}

#include <iostream>
#include "tancrypt/aes.hpp"
#include "tancrypt/hash.hpp"

int main()
{
  // Makes life easier 
  using namespace tancrypt;

  dutils::dbuffer payload("Hewwo, I am secret >.<");

  // Raw key
  dutils::dbuffer raw_key("Oh no, I am nor padded nor hashed!");

  // Hashing the key - this method allows us to pre-hash the key just once and use it multiple times!
  dutils::dbuffer hashed_key = tancrypt::hash(raw_key,tancrypt::hashAlg::SHA256);

  // Setting up the AES Key Container
  AES::keyc my_key(hashed_key, AES::Type::CBC256);

  // Encrypting the data
  dutils::dbuffer encrypted_payload = AES::encrypt(my_key, payload);

  // You can check the results via helper function dutils::hexStr
  std::cout << "Original: " << payload.toStr() << std::endl; 
  std::cout << "Original(hex): " << dutils::hexStr(payload) << std::endl; 
  std::cout << "Encrypted: " << encrypted_payload.toStr() << std::endl;
  std::cout << "Encrypted(hex): " << dutils::hexStr(encrypted_payload) << std::endl;

  return 0;
}

Decrypt

Is a static stateless function, uses AES Key Container as AES parameters.
Takes the buffer by reference and returns a new decrypted copy of the data.

AES::decrypt(AES::keyc &key_container, dutils::dbuffer &buffer)

• Parameters:
  • tancrypt::AES::keyc &key_container - AES key with preloaded credentials
  • dutils::dbuffer &buffer - Data to decrypt
• Returns:
  • dutils::dbuffer AES_DATA - Decrypted buffer

In case of a failure throws an exception.

Example

Hashed KeyRaw Key

#include <iostream>
#include "tancrypt/aes.hpp"

int main()
{
  // Makes life easier 
  using namespace tancrypt;

  // Data and key setup 
  dutils::dbuffer payload;
  // Assuming whatever encrypted data was loaded into the dbuffer here
  //...
  dutils::dbuffer my_keydata("Hewwo, I am key ^.^");

  // Setting up AES Key Container
  AES::keyc my_key(my_keydata, AES::Type::CBC256, hashAlg::SHA256);

  // Decrypting the data
  dutils::dbuffer encrypted_payload = AES::encrypt(my_key, payload);


  // You can check the results via helper function dutils::hexStr
  std::cout << "Original: " << payload.toStr() << std::endl; 
  std::cout << "Original(hex): " << dutils::hexStr(payload) << std::endl; 
  std::cout << "Decrypted(hex): " << dutils::hexStr(decrypted_buffer) << std::endl;
  std::cout << "Decrypted: " << decrypted_buffer.data() << std::endl;

  return 0;
}

#include <iostream>
#include "tancrypt/aes.hpp"
#include "tancrypt/hash.hpp"

int main()
{
  // Makes life easier 
  using namespace tancrypt;

  // Data and key setup 
  dutils::dbuffer payload;
  // Assuming whatever encrypted data was loaded into the dbuffer here
  //...
  // Raw key
  dutils::dbuffer raw_key("Oh no, I am nor padded nor hashed!");

  // Hashing the key - this method allows us to pre-hash the key just once and use it multiple times!
  dutils::dbuffer hashed_key = tancrypt::hash(raw_key,tancrypt::hashAlg::SHA256);

  // Setting up the AES Key Container
  AES::keyc my_key(hashed_key, AES::Type::CBC256);

  // You can check the results via helper function dutils::hexStr
  std::cout << "Original: " << payload.toStr() << std::endl; 
  std::cout << "Original(hex): " << dutils::hexStr(payload) << std::endl; 
  std::cout << "Decrypted(hex): " << dutils::hexStr(decrypted_buffer) << std::endl;
  std::cout << "Decrypted: " << decrypted_buffer.data() << std::endl;

  return 0;
}

getNonce

Warning

Please note that this should be only used for ciphers where it's applicable, otherwise logic error exception
"Not applicable" is thrown.

Allows you to retrieve, Nonce from dutils::dbuffer, in order for this operation to succeed the AES::Type is needed to correctly determine length of the Nonce.
Do note however, that this relies on the Nonce to be stored at the start of the buffer.

AES::getNonce(dutils::dbuffer buffer,AES::Type type)

• Parameters:
  • dutils::dbuffer - AES encrypted buffer
  • AES::Type type - Type of the AES cipher, needed to determine nonce/IV length
• Returns:
  • dutils::dbuffer nonce_buffer - Nonce/IV buffer

RefKeylen

Is a static steless function, takes AES::Type and returns length of key for the given AES::type

AES::RefKeylen(AES::Type type)

• Parameters:
  • AES::Type type - Type of the AES cipher, needed to determine nonce/IV length
• Returns:
  • int keylen - Required length of the key for given AES::Type