openssl库中MD算法的使用

最新推荐文章于 2024-09-05 09:44:31 发布

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最新推荐文章于 2024-09-05 09:44:31 发布

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分类专栏： openssl 文章标签： openssl md2 md4 md5

本文链接：https://blog.youkuaiyun.com/zahuopuboss/article/details/9667081

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本文详细介绍了如何在openssl库中运用MD2、MD4和MD5这三种消息摘要算法，包括它们的原理和具体操作步骤，最终展示运行结果。

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MD2

MD4

MD5

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <openssl/md2.h>
#include <openssl/md4.h>
#include <openssl/md5.h>
#include <openssl/crypto.h>

static char *s1 = "abc";
static int s1_len = 3;

char *ret_md2 = "da853b0d3f88d99b30283a69e6ded6bb";
char *ret_md4 = "a448017aaf21d8525fc10ae87aa6729d";
char *ret_md5 = "900150983cd24fb0d6963f7d28e17f72";

static char *pt(unsigned char *md, int len)
{
	int i;
	static char buf[256];

	for (i = 0; i < len; i++)
		sprintf(&(buf[i * 2]), "%02x", md[i]);
	return (buf);
}

void md2(void)
{
	MD2_CTX c;
	unsigned char md[MD2_DIGEST_LENGTH];
	char *p;

	MD2((unsigned char *)s1, s1_len, md);
	p = pt(md, MD2_DIGEST_LENGTH);
	printf("MD2	: %s\n", p);

	MD2_Init(&c);
	MD2_Update(&c, (unsigned char *)s1, s1_len);
	MD2_Final(md, &c);
	OPENSSL_cleanse(&c, sizeof(c));
	p = pt(md, MD2_DIGEST_LENGTH);
	printf("MD2	: %s\n", p);
}

void md4(void)
{
	MD4_CTX c;
	unsigned char md[MD4_DIGEST_LENGTH];
	char *p;

	MD4((unsigned char *)s1, s1_len, md);
	p = pt(md, MD4_DIGEST_LENGTH);
	printf("MD4	: %s\n", p);

	MD4_Init(&c);
	MD4_Update(&c, (unsigned char *)s1, s1_len);
	MD4_Final(md, &c);
	OPENSSL_cleanse(&c, sizeof(c));
	p = pt(md, MD4_DIGEST_LENGTH);
	printf("MD4	: %s\n", p);
}

void md5(void)
{
	MD5_CTX c;
	unsigned char md[MD5_DIGEST_LENGTH];
	char *p;

	MD5((unsigned char *)s1, s1_len, md);
	p = pt(md, MD5_DIGEST_LENGTH);
	printf("MD5	: %s\n", p);

	MD5_Init(&c);
	MD5_Update(&c, (unsigned char *)s1, s1_len);
	MD5_Final(md, &c);
	OPENSSL_cleanse(&c, sizeof(c));
	p = pt(md, MD5_DIGEST_LENGTH);
	printf("MD5	: %s\n", p);
}

int main(int argc, char *argv[])
{
	if (argc > 1) {
		s1 = argv[1];
	}
	s1_len = strlen(s1);

	printf("calculating MD* on '%s'\n", s1);

	md2();
	md4();
	md5();

	return 0;
}

运行结果

$ gcc -Wall -lcrypto md.c


$ ./a.out 
calculating MD* on 'abc'
MD2     : da853b0d3f88d99b30283a69e6ded6bb
MD2     : da853b0d3f88d99b30283a69e6ded6bb
MD4     : a448017aaf21d8525fc10ae87aa6729d
MD4     : a448017aaf21d8525fc10ae87aa6729d
MD5     : 900150983cd24fb0d6963f7d28e17f72
MD5     : 900150983cd24fb0d6963f7d28e17f72


$ ./a.out 123
calculating MD* on '123'
MD2     : ef1fedf5d32ead6b7aaf687de4ed1b71
MD2     : ef1fedf5d32ead6b7aaf687de4ed1b71
MD4     : c58cda49f00748a3bc0fcfa511d516cb
MD4     : c58cda49f00748a3bc0fcfa511d516cb
MD5     : 202cb962ac59075b964b07152d234b70
MD5     : 202cb962ac59075b964b07152d234b70