文章目录
openssl3.2 - 官方demo学习 - cms - cms_comp.c
概述
CMS is Cryptographic Message Syntax (CMS) standard
用CMS操作, 将明文压缩
默认编译出来的openssl3.2没有zlib库, 需要添加zlib特性[openssl3.2 - 编译](https://lostspeed.blog.csdn.net/article/details/135436821)笔记
c
/*! \file cms_comp.c
\note CMS is Cryptographic Message Syntax (CMS) standard
openssl3.2 - 官方demo学习 - cms - cms_comp.c
用CMS操作, 将明文压缩
*/
/*
* Copyright 2008-2023 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
/* Simple S/MIME compress example */
#include <openssl/pem.h>
#include <openssl/cms.h>
#include <openssl/err.h>
#include "my_openSSL_lib.h"
int main(int argc, char **argv)
{
BIO *in = NULL, *out = NULL;
CMS_ContentInfo *cms = NULL;
int ret = EXIT_FAILURE;
/*
* On OpenSSL 1.0.0+ only:
* for streaming set CMS_STREAM
*/
int flags = CMS_STREAM;
OpenSSL_add_all_algorithms();
ERR_load_crypto_strings();
/* Open content being compressed */
in = BIO_new_file("comp.txt", "r");
if (!in)
goto err;
/* compress content */
cms = CMS_compress(in, NID_zlib_compression, flags);
if (!cms)
goto err;
out = BIO_new_file("smcomp.txt", "w");
if (!out)
goto err;
/* Write out S/MIME message */
/*! int SMIME_write_CMS(BIO *bio, CMS_ContentInfo *cms, BIO *data, int flags);*/
if (!SMIME_write_CMS(out, cms, in, flags))
goto err;
ret = EXIT_SUCCESS;
err:
if (ret != EXIT_SUCCESS) {
fprintf(stderr, "Error Compressing Data\n");
ERR_print_errors_fp(stderr);
}
CMS_ContentInfo_free(cms); /*! CMS_compress出来的东西要free */
/*! BIO_new_file()出来的东西要free */
BIO_free(in);
BIO_free(out);
return ret;
}