Added Menu with Both options. Encoding a file seems to have a padding issue.

1 files changed, 141 insertions, 0 deletions

diff --git a/CST 126/Homework 2/main.cpp b/CST 126/Homework 2/main.cpp
new file mode 100644
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+++ b/CST 126/Homework 2/main.cpp
@@ -0,0 +1,141 @@
+// Name: Logan Gillespie
+// Class: CST 126
+// Date: 5/16/24
+// Assignment: Homework 2
+
+#include <iostream>
+#include <fstream>
+#include <sstream>
+
+std::string encodeFileToBase64(const std::string& filename);
+std::string decodeBase64(const std::string& encoded);
+bool decodeBase64ToFile(const std::string& base64Data, const std::string& filename);
+
+int main()
+{
+    int choice = 0;
+    do {
+        std::cout << "Welcome to my program! Here are your options:" << std::endl;
+        std::cout << "0. Quit" << std::endl;
+        std::cout << "1. Encode File to Base64" << std::endl;
+        std::cout << "2. Decode Base64 to File" << std::endl;
+        std::cin >> choice;
+        switch (choice) {
+        case 1:
+        {
+            std::string filename = "encode.txt";
+            std::string base64Data = encodeFileToBase64(filename);
+            std::cout << "Base64 Encoded Data:\n" << base64Data << std::endl;
+            break;
+        }
+        case 2:
+        {
+            std::string base64Data;
+            std::cout << "Enter Base64 encoded data: ";
+            std::cin >> base64Data;
+
+            std::string filename;
+            std::cout << "Enter output filename: ";
+            std::cin >> filename;
+
+            if (decodeBase64ToFile(base64Data, filename)) {
+                std::cout << "File successfully decoded and written: " << filename << std::endl;
+            }
+            else {
+                std::cerr << "Failed to decode and write file." << std::endl;
+            }
+            break;
+        }
+        }
+    } while (choice != 0);
+}
+
+std::string encodeFileToBase64(const std::string& filename) {
+    std::ifstream file(filename, std::ios::binary | std::ios::ate);
+    if (!file.is_open()) {
+        std::cerr << "Error: Unable to open file " << filename << std::endl;
+        return "";
+    }
+
+    // Get file size
+    std::streamsize fileSize = file.tellg();
+    file.seekg(0, std::ios::beg);
+
+    // Read file into buffer
+    char* buffer = new char[fileSize];
+    file.read(buffer, fileSize);
+
+    // Base64 encoding table
+    const std::string base64_chars =
+        "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+        "abcdefghijklmnopqrstuvwxyz"
+        "0123456789+/";
+
+    // Encode buffer to Base64
+    std::stringstream encoded;
+    int val = 0, valb = -6;
+    for (int i = 0; i < fileSize; i++) {
+        unsigned char c = buffer[i];
+        val = (val << 8) + c;
+        valb += 8;
+        while (valb >= 0) {
+            encoded << base64_chars[(val >> valb) & 0x3F];
+            valb -= 6;
+        }
+    }
+
+    // Padding with '='
+    while (valb > -6) {
+        encoded << '=';
+        valb -= 6;
+    }
+
+    delete[] buffer;
+    file.close();
+
+    return encoded.str();
+}
+
+std::string decodeBase64(const std::string& encoded) {
+    // Base64 decoding table
+    const std::string base64_chars =
+        "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+        "abcdefghijklmnopqrstuvwxyz"
+        "0123456789+/";
+
+    std::string decoded;
+    int val = 0, valb = -8;
+    for (char c : encoded) {
+        if (c == '=') break;
+        if (base64_chars.find(c) == std::string::npos) {
+            std::cerr << "Error: Invalid Base64 character detected!" << std::endl;
+            return "";
+        }
+        val = (val << 6) + base64_chars.find(c);
+        valb += 6;
+        if (valb >= 0) {
+            decoded.push_back(char((val >> valb) & 0xFF));
+            valb -= 8;
+        }
+    }
+    return decoded;
+}
+
+
+bool decodeBase64ToFile(const std::string& base64Data, const std::string& filename) {
+    std::ofstream file(filename, std::ios::binary);
+    if (!file.is_open()) {
+        std::cerr << "Error: Unable to create file " << filename << std::endl;
+        return false;
+    }
+
+    std::string decodedData = decodeBase64(base64Data);
+    if (decodedData.empty()) {
+        std::cerr << "Error: Failed to decode Base64 data" << std::endl;
+        return false;
+    }
+
+    file.write(decodedData.c_str(), decodedData.size());
+    file.close();
+    return true;
+}
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