Update columnar-transposition example

+ Use inheritance to provide base class for key based ciphers
This commit is contained in:
Shaun Reed 2021-07-22 10:50:29 -04:00
parent b5a97de9ff
commit 58adbfc473
4 changed files with 69 additions and 58 deletions

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@ -4,6 +4,7 @@
shaunrd0/klips/cpp/ shaunrd0/klips/cpp/
├── algorithms # Examples of various algorithms written in C++ ├── algorithms # Examples of various algorithms written in C++
├── cmake # Example of using cmake to build and organize larger projects ├── cmake # Example of using cmake to build and organize larger projects
├── cryptography# Examples of encrypting / decrypting using ciphers in C++
├── datastructs # Collection of useful datastructures written in C++ ├── datastructs # Collection of useful datastructures written in C++
├── graphics # Examples of graphics projects written in C++ ├── graphics # Examples of graphics projects written in C++
├── patterns # Examples of various design patterns written in C++ ├── patterns # Examples of various design patterns written in C++

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@ -27,10 +27,10 @@ int main (const int argc, const char * argv[]) {
// Using example keyword from www.braingle.com // Using example keyword from www.braingle.com
// + The embedded example there doesn't seem to support numbers in keywords :( // + The embedded example there doesn't seem to support numbers in keywords :(
CipherData cData("ZEBRAS"); Columnar cData("ZEBRAS");
// Taking user input for keyword using CipherData ctor // Taking user input for keyword using Columnar ctor
// CipherData cData; // Columnar cData;
int choice = 0; int choice = 0;
bool exit = false; bool exit = false;

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@ -10,8 +10,9 @@
#include "lib-cipher.hpp" #include "lib-cipher.hpp"
// Initializes orderVect to determine order columns should be used KeyData::~KeyData() {}
void CipherData::InitOrder(std::string temp)
void Columnar::InitOrder(std::string temp)
{ {
// Create a temp value sorted lexicographically, remove duplicate characters // Create a temp value sorted lexicographically, remove duplicate characters
// https://en.cppreference.com/w/cpp/string/basic_string/operator_cmp // https://en.cppreference.com/w/cpp/string/basic_string/operator_cmp
@ -32,38 +33,8 @@ void CipherData::InitOrder(std::string temp)
} }
// Allows getting keyWord when using CipherData default ctor void Columnar::ValidateKeyword(const std::string &message)
std::string CipherData::GetKey()
{ {
std::string key;
std::cout << "Enter the keyword: ";
std::getline(std::cin, key);
std::cout << "Keyword entered: \"" << key << "\"\n";
return key;
}
// Transpose a character matrix, using a vector of strings
void CipherData::Transpose(const std::vector<std::string> &in,
std::vector<std::string> &out)
{
int cols = in[0].size();
// JIC some other row is larger than the first
for (const auto &row : in) cols = (row.size() > cols) ? row.size() : cols;
int rows = in.size();
out.resize(cols);
for (int i = 0; i < cols; i++) {
for (int j = 0; j < rows; j++) {
if (in[j].size() <= i) continue;
out[i] += in[j][i];
}
}
}
void CipherData::ValidateKeyword(const std::string &message)
{
if (keyWord_.size() < message.size()) return;
// Pop letters from keyWord until it is < message.size() // Pop letters from keyWord until it is < message.size()
while (keyWord_.size() >= message.size()) keyWord_.pop_back(); while (keyWord_.size() >= message.size()) keyWord_.pop_back();
// Do not append order to a previous orderVect; Erase it first // Do not append order to a previous orderVect; Erase it first
@ -72,7 +43,25 @@ void CipherData::ValidateKeyword(const std::string &message)
InitOrder(keyWord_); InitOrder(keyWord_);
} }
std::string CipherData::Encrypt(std::string message) void Columnar::Transpose(const std::vector<std::string> &in,
std::vector<std::string> &out)
{
size_t cols = in[0].size();
// JIC some other row is larger than the first
for (const auto &row : in) cols = (row.size() > cols) ? row.size() : cols;
size_t rows = in.size();
out.resize(cols);
for (size_t i = 0; i < cols; i++) {
for (size_t j = 0; j < rows; j++) {
if (in[j].size() <= i) continue;
out[i] += in[j][i];
}
}
}
std::string Columnar::Encrypt(std::string message)
{ {
// If no message was provided, ask for one // If no message was provided, ask for one
if (message.empty()) { if (message.empty()) {
@ -80,7 +69,7 @@ std::string CipherData::Encrypt(std::string message)
std::getline(std::cin, message); std::getline(std::cin, message);
std::cout << "Encrypting message \"" << message << "\"\n"; std::cout << "Encrypting message \"" << message << "\"\n";
} }
ValidateKeyword(message); if (keyWord_.size() >= message.size()) ValidateKeyword(message);
std::string encryptedMessage; std::string encryptedMessage;
std::vector<std::string> rows; std::vector<std::string> rows;
@ -99,7 +88,7 @@ std::string CipherData::Encrypt(std::string message)
return encryptedMessage; return encryptedMessage;
} }
std::string CipherData::Decrypt(std::string message) std::string Columnar::Decrypt(std::string message)
{ {
// If no message was provided, ask for one // If no message was provided, ask for one
if (message.empty()) { if (message.empty()) {
@ -107,7 +96,7 @@ std::string CipherData::Decrypt(std::string message)
std::getline(std::cin, message); std::getline(std::cin, message);
std::cout << "Decrypting message \"" << message << "\"\n"; std::cout << "Decrypting message \"" << message << "\"\n";
} }
ValidateKeyword(message); if (keyWord_.size() >= message.size()) ValidateKeyword(message);
std::string decryptedMessage; std::string decryptedMessage;
std::vector<std::string> rows; std::vector<std::string> rows;

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@ -16,37 +16,58 @@
#include<vector> #include<vector>
/******************************************************************************/ /******************************************************************************/
// CipherData struct to hold data and methods related to encrypting / decrypting // KeyData struct to hold data related to key ciphers
struct CipherData { struct KeyData {
explicit KeyData(std::string key) : keyWord_(std::move(key)) {};
explicit KeyData() : keyWord_(GetKey()) {};
// Pure virtual dtor to make abstract class despite no pure virtual members
virtual ~KeyData() = 0;
// Allows getting keyWord when using KeyData default ctor
static std::string GetKey()
{
std::string key;
std::cout << "Enter the keyword: ";
std::getline(std::cin, key);
std::cout << "Keyword entered: \"" << key << "\"\n";
return key;
}
protected:
std::string keyWord_;
};
// Definition of pure virtual dtor
/******************************************************************************/
// Columnar struct to define methods related to columnar transposition
struct Columnar : KeyData {
// Can't create this object without providing a keyWord to initialize order // Can't create this object without providing a keyWord to initialize order
explicit CipherData(std::string keyWord) : keyWord_(std::move(keyWord)) explicit Columnar(std::string keyWord) : KeyData(std::move(keyWord))
{ {
InitOrder(keyWord_); InitOrder(keyWord_);
} }
CipherData() : keyWord_(GetKey()) { InitOrder(keyWord_);} // Inherit call to GetKey() from KeyData default ctor
Columnar() { InitOrder(keyWord_);}
/****************************************************************************/ // Initializes orderVect to determine order columns should be used
// Member functions
// Initializes orderVect, pass by value to create local copy of keyWord
void InitOrder(std::string temp); void InitOrder(std::string temp);
static std::string GetKey();
static void /****************************************************************************/
Transpose(const std::vector<std::string> &in, std::vector<std::string> &out); // Member function definitions
// Default values for param allows calling with no message void ValidateKeyword(const std::string &message);
// Transpose a character matrix, using a vector of strings
static void Transpose(const std::vector<std::string> &in,
std::vector<std::string> &out);
// Default parameter allows calling Encrypt() to take message input
std::string Encrypt(std::string message=""); std::string Encrypt(std::string message="");
// Default parameter allows calling Decrypt() to take message input
std::string Decrypt(std::string message=""); std::string Decrypt(std::string message="");
private: private:
// Used to make a valid keyword from an invalid keyWord
// + Still encrypts / decrypts with whatever the user inputs as keyWord
// + But technically the keyword is modified without the user knowing :)
void ValidateKeyword(const std::string &message);
std::string keyWord_;
std::vector<int> orderVect_; std::vector<int> orderVect_;
}; };