aes 256 in grypt

gcrypt_aes256.cpp

#include <cassert>
#include <sstream>
#include <iomanip>
#include <iostream>
#include <map>
#include <set>
#include <vector>
#include <gcrypt.h>
#include <string>

void closeHandle( gcry_cipher_hd_t &handle )
{
   gcry_cipher_close( handle );
}

char _s_gKey[32]{
        '1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6', 
        '1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6'            
};

void printCharsAsHex( const char* charArr, const int encryptedSize )
{
    std::stringstream ss;
    for(int i = 0; i < encryptedSize; ++i)
    {
     ss << std::hex << std::setw(2) << std::setfill('0') << int(charArr[i])  << " ";
    }
    ss << "\n";
    std::cout << "*****************EncryptedData********************" << std::endl;
    std::cout << ss.str() << std::endl;    
    std::cout << "**************************************************" << std::endl;
} 

void openHandle( gcry_cipher_hd_t &handle, uint32_t &blkLength )
{
   gcry_error_t            err       = GPG_ERR_NO_ERROR;
   const gcry_cipher_algos MyCipher  = GCRY_CIPHER_AES256;
   const uint32_t          KeyLength = gcry_cipher_get_algo_keylen( MyCipher );
   assert( KeyLength == 32 );
   blkLength = gcry_cipher_get_algo_blklen( MyCipher );
   static bool s_isCipherInitialized = false;
   if ( s_isCipherInitialized == false )
   {
      static_cast<void>( gcry_control( GCRYCTL_ANY_INITIALIZATION_P ) );
      static_cast<void>( gcry_control( GCRYCTL_DISABLE_SECMEM, 0 ) );
      static_cast<void>( gcry_control( GCRYCTL_INITIALIZATION_FINISHED ) );
      s_isCipherInitialized = true;
   }
   err = gcry_cipher_open( &handle, MyCipher, GCRY_CIPHER_MODE_CFB, 0 );
   err = gcry_cipher_setkey( handle, _s_gKey, KeyLength );
}


int main(int argc, char** argv){
    uint32_t data_ptr_buf_len = 32;
    char data[data_ptr_buf_len + 1]{'a','b','c','d','e','f','g','h','a','b','c','d','e','f','g','h', '\0'};
    std::cout << "**************** Original Data*******************" << std::endl;
    std::cout << data << std::endl;
    std::cout << "*************************************************" << std::endl;

    
    gcry_cipher_hd_t handle;
    memset(&handle, 0, sizeof(handle));
    uint32_t blkLength = 0;

    openHandle( handle, blkLength );
    gcry_error_t err = GPG_ERR_NO_ERROR;
    err = gcry_cipher_encrypt(handle, data, data_ptr_buf_len, NULL, 0);
    closeHandle(handle);
    
    printCharsAsHex( data, data_ptr_buf_len );    
    

    openHandle(handle, blkLength);
    err = gcry_cipher_decrypt(handle, data, data_ptr_buf_len, NULL, 0);
    closeHandle(handle);
    std::string s(data);
    std::cout << "*************** Decrypted Data *******************" << std::endl;
    std::cout << s << std::endl;
    std::cout << "**************************************************" << std::endl;
}