I am writing a code to encrypt and decrypt with crypto++ library .I found a code to encrypt and decrypt which is shown below.The code works OK as one program.but when I divide into two c++ programs (One for encryption and another for decryption) the decryption pargram gives me error
terminate called after throwing an instance of 'CryptoPP::InvalidCiphertext' what(): StreamTransformationFilter: ciphertext length is not a multiple of block size
The ciphertext I get after encryption is
���z=(f�����P%���2��W3�p�H�����^��@C��#������bp���nx��
which I transfer into the decryption code. What am I doing wrong?
my first program for encryption is
#include <iostream>
#include <iomanip>
#include <cryptopp/hex.h>
#include <cryptopp/sha.h>
#include <cryptopp/base64.h>
#include <iostream>
#include <string>
#include "crypto++/modes.h"
#include "crypto++/aes.h"
#include "crypto++/filters.h"
int main(int argc, char* argv[]) {
//
// Key and IV setup
//AES encryption uses a secret key of a variable length (128-bit, 196-bit or 256-
//bit). This key is secretly exchanged between two parties before communication
//begins. DEFAULT_KEYLENGTH= 16 bytes
byte key[ CryptoPP::AES::DEFAULT_KEYLENGTH ], iv[ CryptoPP::AES::BLOCKSIZE ];
memset( key, 0x00, CryptoPP::AES::DEFAULT_KEYLENGTH );
memset( iv, 0x00, CryptoPP::AES::BLOCKSIZE );
//
// String and Sink setup
//
std::string plaintext = "Now is the time for all good men to come to the aide...";
std::string ciphertext;
std::string decryptedtext;
//
// Dump Plain Text
//
std::cout << "Plain Text (" << plaintext.size() << " bytes)" << std::endl;
std::cout << plaintext;
std::cout << std::endl << std::endl;
//
// Create Cipher Text
//
CryptoPP::AES::Encryption aesEncryption(key, CryptoPP::AES::DEFAULT_KEYLENGTH);
CryptoPP::CBC_Mode_ExternalCipher::Encryption cbcEncryption( aesEncryption, iv );
CryptoPP::StreamTransformationFilter stfEncryptor(cbcEncryption, new CryptoPP::StringSink( ciphertext ) );
stfEncryptor.Put( reinterpret_cast<const unsigned char*>( plaintext.c_str() ), plaintext.length() + 1 );
stfEncryptor.MessageEnd();
//
// Dump Cipher Text
//
std::cout << "Cipher Text (" << ciphertext.size() << " bytes)" << std::endl;
for( int i = 0; i < ciphertext.size(); i++ ) {
std::cout << "0x" << std::hex << (0xFF & static_cast<byte>(ciphertext[i])) << " ";
}
std::cout << std::endl << std::endl;
/////////////////////////////////////////////////////////////////////////
return 0;
}
I am sending the ciphertext using URL eg. https://xxx.xxx.xx.xx/_SERVER_TEST.fcgi?���z=(f�����P%���2��W3�p�H�����^��@C��#������bp���nx��
and on the other side I an trying to decript my ciphertext . but the URL dont understand the cipher.
my second program Decryption is
#include <iostream>
#include <iomanip>
#include <cryptopp/hex.h>
#include <cryptopp/sha.h>
#include <cryptopp/base64.h>
#include <iostream>
#include <string>
#include "crypto++/modes.h"
#include "crypto++/aes.h"
#include "crypto++/filters.h"
int main(int argc, char* argv[]) {
//
// Key and IV setup
//AES encryption uses a secret key of a variable length (128-bit, 196-bit or 256-
//bit). This key is secretly exchanged between two parties before communication
//begins. DEFAULT_KEYLENGTH= 16 bytes
byte key[ CryptoPP::AES::DEFAULT_KEYLENGTH ], iv[ CryptoPP::AES::BLOCKSIZE ];
memset( key, 0x00, CryptoPP::AES::DEFAULT_KEYLENGTH );
memset( iv, 0x00, CryptoPP::AES::BLOCKSIZE );
std::string ciphertext;
std::string decryptedtext;
//
// Decrypt
//
CryptoPP::AES::Decryption aesDecryption(key, CryptoPP::AES::DEFAULT_KEYLENGTH);
CryptoPP::CBC_Mode_ExternalCipher::Decryption cbcDecryption( aesDecryption, iv );
CryptoPP::StreamTransformationFilter stfDecryptor(cbcDecryption, new CryptoPP::StringSink( decryptedtext ) );
stfDecryptor.Put( reinterpret_cast<const unsigned char*>( ciphertext.c_str() ), ciphertext.size() );
stfDecryptor.MessageEnd();
//
// Dump Decrypted Text
//
std::cout << "Decrypted Text: " << std::endl;
std::cout << decryptedtext;
std::cout << std::endl << std::endl;
/////////////////////////////////////////////////////////////////////////
return 0;
}