testing

XOR_Encryption/README.md

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+# XOR Cipher
+
+## Description
+This project implements a simple XOR cipher for encrypting and decrypting text using a key. XOR encryption is a symmetric operation, meaning the same function is used to both encrypt and decrypt data.
+
+## Directory Structure
+- `include/`: Contains the header files.
+- `src/`: Contains the source code files (`main.c` and `xor_cipher.c`).
+- `obj/`: Contains the compiled object files.
+- `build/`: Contains the Makefile and the compiled binary.
+
+## How to Build
+1. Navigate to the `build` directory.
+2. Run `make` to compile the project.
+
+## How to Run
+1. After building, you will find an executable named `xor_cipher` in the `build` directory.
+2. Run it using `./xor_cipher`.
+
+## How to Clean
+- Run `make clean` in the `build` directory to remove all compiled files.

XOR_Encryption/build/Makefile

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+# Variables
+CC = gcc
+CFLAGS = -I../include -Wall -Wextra
+OBJDIR = ../obj
+SRCDIR = ../src
+BINDIR = ../build
+
+# Source files
+SOURCES = $(SRCDIR)/main.c $(SRCDIR)/xor_cipher.c
+OBJECTS = $(OBJDIR)/main.o $(OBJDIR)/xor_cipher.o
+
+# Build target
+TARGET = xor_cipher
+
+# Rules
+all: $(BINDIR)/$(TARGET)
+
+$(BINDIR)/$(TARGET): $(OBJECTS)
+	$(CC) $(OBJECTS) -o $(BINDIR)/$(TARGET)
+
+$(OBJDIR)/%.o: $(SRCDIR)/%.c
+	$(CC) $(CFLAGS) -c $< -o $@
+
+clean:
+	rm -f $(OBJDIR)/*.o $(BINDIR)/$(TARGET)
+
+.PHONY: all clean

XOR_Encryption/include/xor_cipher.h

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+#ifndef XOR_CIPHER_H
+#define XOR_CIPHER_H
+
+void xor_encrypt_decrypt(char *data, const char *key);
+
+#endif // XOR_CIPHER_H

XOR_Encryption/src/main.c

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+#include "xor_cipher.h"
+#include <stdio.h>
+#include <string.h>
+
+// Function to display encrypted message in hexadecimal format
+void print_hex(const char *data) {
+    for (int i = 0; data[i] != '\0'; i++) {
+        printf("%02x ", (unsigned char)data[i]);
+    }
+    printf("\n");
+}
+
+// Function to safely print decrypted message, replacing nulls with spaces
+void print_decrypted_message(const char *data) {
+    for (int i = 0; data[i] != '\0'; i++) {
+        // If the character is NULL, print a space instead
+        putchar(data[i] == '\0' ? ' ' : data[i]);
+    }
+    printf("\n");
+}
+
+int main() {
+    char message[256];
+    char key[256];
+
+    // Get the message to encrypt
+    printf("Enter a message to encrypt: ");
+    fgets(message, sizeof(message), stdin);
+    message[strcspn(message, "\n")] = '\0'; // Remove newline character
+
+    // Get the encryption key
+    printf("Enter the encryption key: ");
+    fgets(key, sizeof(key), stdin);
+    key[strcspn(key, "\n")] = '\0'; // Remove newline character
+
+    // Check if message or key is empty
+    if (strlen(message) == 0 || strlen(key) == 0) {
+        printf("Error: Message or key cannot be empty.\n");
+        return 1;
+    }
+
+    // Encrypt the message
+    xor_encrypt_decrypt(message, key);
+    printf("Encrypted message (hexadecimal): ");
+    print_hex(message);
+
+    // Decrypt the message (using the same function, since XOR is symmetric)
+    xor_encrypt_decrypt(message, key);
+    printf("Decrypted message: ");
+    print_decrypted_message(message);
+
+    return 0;
+}
+

XOR_Encryption/src/xor_cipher.c

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+#include "xor_cipher.h"
+#include <string.h>
+#include <stdio.h>
+
+void xor_encrypt_decrypt(char *data, const char *key) {
+    int keyLength = strlen(key);
+    for (int i = 0; data[i] != '\0'; i++) {
+        data[i] ^= key[i % keyLength];
+    }
+}