关于在LinuxC下实现使用openssl库进行des-cbc加解密后base64编码解码的记录

解码编码过程

在过程中主要是以xml文档为加密因子，使用HTTP Request的方式把加密后的xml文档发送到服务器上然后把服务器返回的加密报文进行解密解码。
所需要的库就是#include <openssl/evp.h>

des-cbc解密加密代码

// des-cbc加密
int kk_encrypt(unsigned char *plaintext, int plaintext_len, unsigned char *key,
               unsigned char *iv, unsigned char *ciphertext)
{
   
   
    EVP_CIPHER_CTX *ctx;

    int len;

    int ciphertext_len;
    ctx = EVP_CIPHER_CTX_new();
    EVP_EncryptInit_ex(ctx, EVP_des_cbc(), NULL, key, iv);
    printf("key:%s,iv:%s\r\n",key,iv);

    EVP_EncryptUpdate(ctx, ciphertext, &len, plaintext, plaintext_len);
    ciphertext_len = len;
    EVP_EncryptFinal_ex(ctx, ciphertext + len, &len);
    ciphertext_len += len;
    EVP_CIPHER_CTX_free(ctx);

    return ciphertext_len;
}

// des-cbc解密
int kk_encrypt(unsigned char *plaintext, int plaintext_len, unsigned char *key,
               unsigned char *iv, unsigned char *ciphertext)
{
   
   
    EVP_CIPHER_CTX *ctx;

    int len;

    int ciphertext_len;
    ctx = EVP_CIPHER_CTX_new();
    EVP_EncryptInit_ex(ctx, EVP_des_cbc(), NULL, key, iv);
    printf("key:%s,iv:%s\r\n",key,iv);

    EVP_EncryptUpdate(ctx, ciphertext, &len, plaintext, plaintext_len);
    ciphertext_len = len;
    EVP_EncryptFinal_ex(ctx, ciphertext + len,</