openssl3.2 - 官方demo学习 - cms - cms_uncomp.c(官方应用实现错误, 需要修正)

概述

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

笔记

/*! \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 __int64flags	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;
}

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