C语言中怎样进行文件加密 C语言文件异或加密算法实现

#include <stdio.h>
#include <stdlib.h>

void xor_encrypt_decrypt(const char *input_file, const char *output_file, char key) {
    FILE *fin, *fout;
    int ch;

    fin = fopen(input_file, "rb"); // 以二进制只读方式打开输入文件
    if (fin == NULL) {
        perror("Error opening input file");
        exit(EXIT_FAILURE);
    }

    fout = fopen(output_file, "wb"); // 以二进制写入方式打开输出文件
    if (fout == NULL) {
        perror("Error opening output file");
        fclose(fin);
        exit(EXIT_FAILURE);
    }

    while ((ch = fgetc(fin)) != EOF) {
        fputc(ch ^ key, fout); // 异或运算并写入输出文件
    }

    fclose(fin);
    fclose(fout);

    printf("File processed successfully.\n");
}

int main() {
    char input_file[100], output_file[100];
    char key;

    printf("Enter input file name: ");
    scanf("%s", input_file);

    printf("Enter output file name: ");
    scanf("%s", output_file);

    printf("Enter encryption key (a single character): ");
    scanf(" %c", &key); // 注意空格，防止读取到之前输入的回车

    xor_encrypt_decrypt(input_file, output_file, key);

    return 0;
}

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <openssl/aes.h>
#include <openssl/rand.h>

// 函数：AES加密
int aes_encrypt(const char *input_file, const char *output_file, const unsigned char *key, const unsigned char *iv) {
    FILE *fin, *fout;
    unsigned char in[AES_BLOCK_SIZE];
    unsigned char out[AES_BLOCK_SIZE];
    AES_KEY aes_key;
    size_t bytes_read;

    // 初始化AES密钥
    if (AES_set_encrypt_key(key, 128, &aes_key) < 0) {
        fprintf(stderr, "AES_set_encrypt_key() failed!\n");
        return -1;
    }

    // 打开输入和输出文件
    fin = fopen(input_file, "rb");
    if (fin == NULL) {
        perror("Error opening input file");
        return -1;
    }

    fout = fopen(output_file, "wb");
    if (fout == NULL) {
        perror("Error opening output file");
        fclose(fin);
        return -1;
    }

    // 加密数据
    while ((bytes_read = fread(in, 1, AES_BLOCK_SIZE, fin)) > 0) {
        AES_cbc_encrypt(in, out, bytes_read, &aes_key, iv, AES_ENCRYPT);
        fwrite(out, 1, bytes_read, fout);
    }

    // 关闭文件
    fclose(fin);
    fclose(fout);

    return 0;
}

int main() {
    char input_file[100], output_file[100];
    unsigned char key[16]; // 128-bit key
    unsigned char iv[AES_BLOCK_SIZE]; // Initialization Vector

    printf("Enter input file name: ");
    scanf("%s", input_file);

    printf("Enter output file name: ");
    scanf("%s", output_file);

    // 生成随机密钥和IV
    if (!RAND_bytes(key, sizeof(key)) || !RAND_bytes(iv, sizeof(iv))) {
        fprintf(stderr, "Error generating random key/IV\n");
        return 1;
    }

    // 调用加密函数
    if (aes_encrypt(input_file, output_file, key, iv) != 0) {
        fprintf(stderr, "Encryption failed!\n");
        return 1;
    }

    printf("File encrypted successfully.\n");

    // 打印密钥和IV（实际应用中应安全存储）
    printf("Key: ");
    for (int i = 0; i < sizeof(key); i++) {
        printf("%02x", key[i]);
    }
    printf("\nIV: ");
    for (int i = 0; i < sizeof(iv); i++) {
        printf("%02x", iv[i]);
    }
    printf("\n");

    return 0;
}