openssl3.2 - exp - class warp for sha3-512

概述

前面实验整了一个对buffer进行sha3-512算hash的函数。
实际用的时候，要对几个buffer连续做hash. 前面封装的统一做hash的函数不适用。
重新封装了一个类，只要在类的生命周期中，就可以随时对连续的buffer(可能不在一个函数中)做hash的update.

笔记

调用方代码

bool CPeFileCheck::calc_hash_SHA3_512()
{bool b_rc = false;CCipherSha3_512 hash;do {if (!hash.begin()){break;}// 如果buffer不在一个函数中，将hash的指针传给那些函数做hash.updateif (!hash.update(this->m_pu8_map_file, this->m_u32_file_size)){break;}if (!hash.end()){break;}m_digest_length = hash.get_md_len();if (m_digest_length > sizeof(m_ary_digest_value)){break;}memcpy(m_ary_digest_value, hash.get_md(), hash.get_md_len());b_rc = true;} while (false);return b_rc;
}

子类 - cipher_sha3_512.h

//! \file cipher_sha3_512.h#ifndef __CIPHER_SHA3_512_H__
#define __CIPHER_SHA3_512_H__#include "cipher_md_base.h"class CCipherSha3_512 : public CCipherMdBase
{
public:CCipherSha3_512();virtual ~CCipherSha3_512();
};#endif // #ifndef __CIPHER_SHA3_512_H__

子类 - cipher_sha3_512.cpp

//! \file cipher_sha3_512.cpp#include "pch.h"
#include "cipher_sha3_512.h"CCipherSha3_512::CCipherSha3_512()
{setCiphherName("SHA3-512");
}CCipherSha3_512::~CCipherSha3_512()
{
}

基类 - cipher_md_base.h

//! \file cipher_md_base.h#ifndef __CIPHER_MD_BASE_H__
#define __CIPHER_MD_BASE_H__#include <openssl/evp.h>
#include <string>//! \ref https://blog.csdn.net/LostSpeed/article/details/135581192
class CCipherMdBase
{
public:CCipherMdBase();virtual ~CCipherMdBase();bool begin();bool update(uint8_t* pBuf, int lenBuf);bool end();unsigned int get_md_len() { return m_digest_length; }uint8_t* get_md() { return m_p_digest_value; }void setCiphherName(const char* pszNmae) { m_strCipherName = ((NULL != pszNmae) ? pszNmae : ""); }private:void clear();private:std::string m_strCipherName;OSSL_LIB_CTX* m_ossl_lib_ctx;EVP_MD* m_evp_md;EVP_MD_CTX* m_evp_md_ctx;unsigned int m_digest_length;uint8_t* m_p_digest_value;
};#endif // #ifndef __CIPHER_MD_BASE_H__

基类 - cipher_md_base.cpp

//! \file cipher_md_base.cpp#include "pch.h"
#include "cipher_md_base.h"CCipherMdBase::CCipherMdBase(): m_ossl_lib_ctx(NULL),m_evp_md(NULL),m_evp_md_ctx(NULL),m_digest_length(0),m_p_digest_value(NULL)
{}CCipherMdBase::~CCipherMdBase()
{clear();
}void CCipherMdBase::clear()
{if (NULL != m_evp_md_ctx){EVP_MD_CTX_free(m_evp_md_ctx);m_evp_md_ctx = NULL;}m_digest_length = 0;if (NULL != m_p_digest_value){OPENSSL_free(m_p_digest_value);m_p_digest_value = NULL;}if (NULL != m_evp_md){EVP_MD_free(m_evp_md);m_evp_md = NULL;}if (NULL != m_ossl_lib_ctx){OSSL_LIB_CTX_free(m_ossl_lib_ctx);m_ossl_lib_ctx = NULL;}
}bool CCipherMdBase::begin()
{bool b_rc = false;const char* _psz_option_properties = NULL;do {clear();m_ossl_lib_ctx = OSSL_LIB_CTX_new();if (NULL == m_ossl_lib_ctx) {// fprintf(stderr, "OSSL_LIB_CTX_new() returned NULL\n");break;}/** Fetch a message digest by name* The algorithm name is case insensitive.* See providers(7) for details about algorithm fetching*/if (m_strCipherName.empty()){break;}m_evp_md = EVP_MD_fetch(m_ossl_lib_ctx, m_strCipherName.data(), _psz_option_properties);if (NULL == m_evp_md) {// fprintf(stderr, "EVP_MD_fetch could not find SHA3-512.");break;}/** Make a message digest context to hold temporary state* during digest creation*/m_evp_md_ctx = EVP_MD_CTX_new();if (NULL == m_evp_md_ctx) {// fprintf(stderr, "EVP_MD_CTX_new failed.\n");break;}/** Initialize the message digest context to use the fetched* digest provider*/if (EVP_DigestInit(m_evp_md_ctx, m_evp_md) != 1) {// fprintf(stderr, "EVP_DigestInit failed.\n");break;}b_rc = true;} while (false);return b_rc;
}bool CCipherMdBase::update(uint8_t* pBuf, int lenBuf)
{bool b_rc = false;do {if (EVP_DigestUpdate(m_evp_md_ctx, pBuf, lenBuf) != 1) {// fprintf(stderr, "EVP_DigestUpdate(hamlet_1) failed.\n");break;}b_rc = true;} while (false);return b_rc;}bool CCipherMdBase::end()
{bool b_rc = false;int digest_length = 0;do {/* Determine the length of the fetched digest type */m_digest_length = EVP_MD_get_size(m_evp_md);if (m_digest_length <= 0) {// fprintf(stderr, "EVP_MD_get_size returned invalid size.\n");break;}m_p_digest_value = (uint8_t*)OPENSSL_malloc(m_digest_length);if (NULL == m_p_digest_value) {// fprintf(stderr, "No memory.\n");break;}if (EVP_DigestFinal(m_evp_md_ctx, m_p_digest_value, &m_digest_length) != 1) {// fprintf(stderr, "EVP_DigestFinal() failed.\n");break;}b_rc = true;} while (false);return b_rc;
}

备注

这个封装类用的很舒服。
如果要做其他种类的hash, 只需要继承一个子类，给定新的hash算法名称就行。

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