cms数据解压缩
请注意函数定义 CMS_uncompress(CMS_ContentInfo *cms, BIO *dcont, BIO *out, unsigned int flags)
参数3才是输出的BIO
/*! \file cms_uncomp.c
\note cms数据解压缩
openssl3.2 - 官方demo学习 - cms - cms_uncomp.c(官方应用实现错误, 需要修正)
请注意函数定义 CMS_uncompress(CMS_ContentInfo *cms, BIO *dcont, BIO *out, unsigned int flags)
参数3才是输出的BIO
*/
/*
* 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 uncompression 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;
OpenSSL_add_all_algorithms();
ERR_load_crypto_strings();
/* Open compressed content */
in = BIO_new_file("smcomp.txt", "r");
if (!in)
goto err;
/* Sign content */
/*! SMIME_write_CMS(out, cms, in, flags) */
/*! CMS_ContentInfo *SMIME_read_CMS_ex(BIO *bio, int flags, BIO **bcont, CMS_ContentInfo **ci); */
/*! cms = SMIME_read_CMS(in, NULL); */
cms = SMIME_read_CMS_ex(in, CMS_STREAM, NULL, NULL); /*! 如果要给flag, 就要调用 SMIME_read_CMS_ex*/
/*!
* SMIME_read_CMS_ex一定读到了上一个程序压缩过的数据 smcomp.txt
- b 0x00000204edec2fb0 {length=143 data=0x00000204ede764b0 "0€\x6\v*咹嗺\r\x1\t\x10\x1\t爛0€\x2\x1" max=168 ...} buf_mem_st *
length 143 unsigned __int64
+ data 0x00000204ede764b0 "0€\x6\v*咹嗺\r\x1\t\x10\x1\t爛0€\x2\x1" char *
max 168 unsigned __int64
flags 0 unsigned long
*/
if (!cms)
goto err;
out = BIO_new_file("smuncomp.txt", "w");
if (!out)
goto err;
/* Uncompress S/MIME message */
/*! flags = CMS_STREAM */
/*! cms = CMS_compress(in, NID_zlib_compression, flags); */
/*!
CMS_ContentInfo *CMS_compress(BIO *in, int comp_nid, unsigned int flags);
int CMS_uncompress(CMS_ContentInfo *cms, BIO *dcont, BIO *out, unsigned int flags);
*/
/*! 现在能肯定解压缩不对, 估计是没按照压缩时的标记进行解压缩 */
/*int CMS_uncompress(CMS_ContentInfo *cms, BIO *dcont, BIO *out, unsigned int flags)
*/
/*!
* 官方demo居然写错了..., 这让大部分新手用户懵逼啊...
* 单步调试了好久, 才明白官方实现调用CMS_uncompress()时, 参数给错了
* 官方原版实现 if (!CMS_uncompress(cms, out, NULL, 0)), 这句错了
* 现在只要库是对的, 库的应用方面出问题是难不住俺的:P
*/
if (!CMS_uncompress(cms, NULL, out, CMS_STREAM /*0*/)) /*!< 修正官方实现 */
{
// 对 cms_comp_c工程压缩的数据进行解压缩, 居然错了...
goto err;
}
ret = EXIT_SUCCESS;
err:
if (ret != EXIT_SUCCESS) {
fprintf(stderr, "Error Uncompressing Data\n");
ERR_print_errors_fp(stderr);
}
CMS_ContentInfo_free(cms);
BIO_free(in);
BIO_free(out);
return ret;
}