ak-fortuna/fortuna
Archived
1
1
Fork 1
Code Issues 2 Pull Requests Projects Releases 1 Activity

generator: add CTR-mode Serpent to random_data()
All checks were successful
continuous-integration/drone/push Build is passing
Details

Browse Source 
operate on a fixed string with randomly generated key and iv block on
each run.

this is neither finished nor correct implementation, it currently also
calls the Decryption routine to prove that it's working properly with
the input given ("Oh, I am fortune's fool!" seemed fitting for fortuna).
This commit is contained in:
surtur 2021-11-15 23:27:17 +01:00
parent b934b11aa9
commit c82d3912f5
Signed by: wanderer
GPG Key ID: 19CE1EC1D9E0486D
1 changed files with 82 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

85
fortuna.cpp
View File

@ -4,6 +4,16 @@
#include "fortuna.h"
#include "generator.h"
#include <cryptopp/osrng.h>
#include <cryptopp/hex.h>
#include <cryptopp/filters.h>
#include <cryptopp/serpent.h>
#include <cryptopp/ccm.h>
#include <cassert>
#include <cstring>
#include <iostream>
namespace fortuna {
Fortuna::Fortuna(){
@ -13,9 +23,78 @@ namespace fortuna {
Fortuna::~Fortuna() = default;
auto Fortuna::random_data(unsigned int n_blocks) -> void {
// TODO(me)
// will one day return random data to the user
}
// for the moment loosely based on
// https://www.cryptopp.com/wiki/CTR_Mode
using CryptoPP::StringSource;
using CryptoPP::StringSink;
using CryptoPP::HexEncoder;
using CryptoPP::StreamTransformationFilter;
using CryptoPP::Serpent;
using CryptoPP::CTR_Mode;
CryptoPP::AutoSeededRandomPool prng;
// use 256bit key
CryptoPP::SecByteBlock key(CryptoPP::Serpent::MAX_KEYLENGTH);
prng.GenerateBlock(key,key.size());
CryptoPP::byte ctr[Serpent::BLOCKSIZE];
prng.GenerateBlock(ctr,sizeof(ctr));
// William Shakespeare, Romeo and Juliet
std::string plain = "Oh, I am fortune's fool!";
std::string cipher, encoded_c, decrypted;
try {
std::cout << "plain text: " << plain << std::endl;
CTR_Mode<Serpent>::Encryption e;
e.SetKeyWithIV(key,key.size(),ctr);
// The StreamTransformationFilter adds padding as required. ECB and
// CBC Mode must be padded to the block size of the cipher. CTR
// mode not.
// the "true" param - pump all of the data immediately to its
// attached transformation
StringSource str_src1(plain,true,
new StreamTransformationFilter(e,
new StringSink(cipher)
) // StreamTransformationFilter
); // StringSource
}
catch(CryptoPP::Exception& e) {
std::cerr << e.what() << std::endl;
exit(1);
}
// Pretty print cipher text
StringSource str_src2(cipher,true,
new HexEncoder(
new StringSink(encoded_c)
) // HexEncoder
); // StringSource
std::cout << "cipher text: " << encoded_c << std::endl;
try {
CTR_Mode<Serpent>::Decryption d;
d.SetKeyWithIV(key,key.size(),ctr);
// The StreamTransformationFilter removes padding as required.
StringSource str_src3(cipher, true,
new StreamTransformationFilter(d,
new StringSink(decrypted)
) // StreamTransformationFilter
); // StringSource
std::cout << "decrypted text: " << decrypted << std::endl;
}
catch(CryptoPP::Exception& e) {
std::cerr << e.what() << std::endl;
exit(1);
}
} //random_data
} // namespace fortuna