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
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
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; }