How to develop a simple file encryption function using MySQL and C++

How to use MySQL and C to develop a simple file encryption function

In modern society, data security is a very important issue. Sensitive data can be effectively protected from unauthorized access through encryption. In this article, we will introduce how to develop a simple file encryption function using MySQL and C. We will achieve this by writing the corresponding code.

First, we need to install the MySQL database and create a database for storing file encryption related information. In MySQL, we can use the following command to create the database and related tables:

CREATE DATABASE file_encryption;
USE file_encryption;

CREATE TABLE files (
id INT AUTO_INCREMENT PRIMARY KEY,
name VARCHAR(100),
encrypted_data VARBINARY(5000)
);

In the above code, we create a database named file_encryption and create a table named files in it. The table has three fields: id, name and encrypted_data. Among them, the id field is an auto-incremented primary key, the name field is used to store the file name, and the encrypted_data field is used to store the encrypted file data.

Next, we can start writing C code. First, we need to include the relevant library files. In this example, we use the MySQL Connector/C library to connect to the MySQL database.

#include <mysql_driver.h>
#include <mysql_connection.h>
#include <cppconn/statement.h>
#include <cppconn/prepared_statement.h>
#include <cppconn/resultset.h>

#include <iostream>
#include <fstream>

using namespace std;

int main() {
    // 创建数据库连接
    sql::mysql::MySQL_Driver* driver;
    sql::Connection* con;

    driver = sql::mysql::get_mysql_driver_instance();
    con = driver->connect("tcp://127.0.0.1:3306", "root", "password");

    // 选择数据库
    con->setSchema("file_encryption");

    // 读取文件内容
    ifstream inputFile("input.txt");
    string fileContent((istreambuf_iterator<char>(inputFile)), istreambuf_iterator<char>());

    // 加密文件内容
    string encryptedContent = encrypt(fileContent);

    // 将加密后的内容存入数据库
    sql::PreparedStatement* pstmt = con->prepareStatement("INSERT INTO files (name, encrypted_data) VALUES (?, ?)");
    pstmt->setString(1, "input.txt");
    pstmt->setString(2, encryptedContent);
    pstmt->execute();

    // 从数据库中读取加密后的内容
    sql::Statement* stmt = con->createStatement();
    sql::ResultSet* res = stmt->executeQuery("SELECT encrypted_data FROM files WHERE name = 'input.txt'");
    res->first();

    // 解密文件内容
    string decryptedContent = decrypt(res->getString("encrypted_data"));

    // 将解密后的内容保存到文件
    ofstream outputFile("output.txt");
    outputFile << decryptedContent;

    // 释放内存
    delete res;
    delete stmt;
    delete pstmt;

    // 关闭数据库连接
    delete con;

    return 0;
}

In the above code, we first created a MySQL database connection and selected the file_encryption database. We then read the content from the file and store it encrypted in the database. Next, we read the encrypted content from the database and decrypt it. Finally, we save the decrypted content to another file.

In the above code, we use the two functions encrypt() and decrypt() to perform encryption and decryption operations. The specific implementation of these functions can be written according to the specific encryption algorithm.

The above is a sample code for developing a simple file encryption function using MySQL and C. Through this example, we can learn how to use MySQL to store encrypted file data, and implement file encryption and decryption operations through C code. Of course, this is just a simple example, and more complex encryption algorithms and logic may be involved in actual applications. Hope this article can be helpful to you!

The above is the detailed content of How to develop a simple file encryption function using MySQL and C++. For more information, please follow other related articles on the PHP Chinese website!