pgp加密 c++语言实现

PGP加密是一种非对称加密算法，使用公钥加密、私钥解密的方式进行加密和解密操作。下面是一个C语言实现PGP加密的示例代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <openssl/rsa.h>
#include <openssl/pem.h>

#define PGP_KEY_FILE "pgp_key.pem"

int main(int argc, char *argv[])
{
    char *plaintext = "Hello, world!";
    char *ciphertext;
    int ciphertext_len;
    FILE *fp;
    RSA *rsa;

    // 读取PGP公钥
    fp = fopen(PGP_KEY_FILE, "rb");
    if (fp == NULL) {
        perror("Failed to open PGP key file");
        exit(EXIT_FAILURE);
    }
    rsa = PEM_read_RSA_PUBKEY(fp, NULL, NULL, NULL);
    fclose(fp);
    if (rsa == NULL) {
        perror("Failed to read PGP public key");
        exit(EXIT_FAILURE);
    }

    // 加密明文
    ciphertext = (char *)malloc(RSA_size(rsa));
    ciphertext_len = RSA_public_encrypt(strlen(plaintext), (unsigned char *)plaintext,
                                        (unsigned char *)ciphertext, rsa, RSA_PKCS1_PADDING);
    if (ciphertext_len == -1) {
        perror("Failed to encrypt plaintext");
        exit(EXIT_FAILURE);
    }

    // 输出密文
    printf("Ciphertext: ");
    for (int i = 0; i < ciphertext_len; i++) {
        printf("%02x", ciphertext[i]);
    }
    printf("\n");

    // 释放资源
    RSA_free(rsa);
    free(ciphertext);

    exit(EXIT_SUCCESS);
}

需要注意的是，这里使用了OpenSSL库来实现PGP加密，需要在编译时链接该库，例如：

gcc -o pgp_encrypt pgp_encrypt.c -lcrypto