OpenSSL安装:
1.github下载最新的OpenSSL:https://github.com/openssl/openssl
2.在linux解压压缩包
3.安装OpenSSL
1 ./config --prefix=/usr/local --openssldir=/usr/local/ssl
2 make && make install
3 ./config shared --prefix=/usr/local --openssldir=/usr/local/ssl
4 make clean
5 make && make install
4.用ln将需要的so文件链接到/usr/lib或者/lib这两个默认的目录下面
1 ln -s /where/you/install/lib/*.so /usr/lib
2 sudo ldconfig
openssl MD5接口:
1 int MD5_Init(MD5_CTX *c);
2 //初始化MD5上下文结构
3
4 int MD5_Update(MD5_CTX *c, const void *data, size_t len);
5 //刷新MD5,将文件连续数据分片放入进行MD5刷新。
6
7 int MD5_Final(unsigned char *md, MD5_CTX *c);
8 //产生最终的MD5数据
9
10 unsigned char *MD5(const unsigned char *d, size_t n, unsigned char *md);
11 //直接产生字符串的MD5
代码实现:
1 #include <iostream>
2 #include <fstream>
3 #include <iomanip>
4 #include <string>
5 #include <openssl/md5.h>
6
7 using namespace std;
8
9 #define MAXDATABUFF 1024
10 #define MD5LENTH 16
11
12 int main(int arc,char *arv[])
13 {
14 string strFilePath = arv[1];
15 ifstream ifile(strFilePath.c_str(),ios::in|ios::binary); //打开文件
16 unsigned char MD5result[MD5LENTH];
17 do
18 {
19 if (ifile.fail()) //打开失败不做文件MD5
20 {
21 cout<<"open file failure!so only display string MD5!"<<endl;
22 break;
23 }
24 MD5_CTX md5_ctx;
25 MD5_Init(&md5_ctx);
26
27 char DataBuff[MAXDATABUFF];
28 while(!ifile.eof())
29 {
30 ifile.read(DataBuff,MAXDATABUFF); //读文件
31 int length = ifile.gcount();
32 if(length)
33 {
34 MD5_Update(&md5_ctx,DataBuff,length); //将当前文件块加入并更新MD5
35 }
36 }
37 MD5_Final(MD5result,&md5_ctx); //获取MD5
38 cout<<"file MD5:"<<endl;
39 for(int i = 0; i < MD5LENTH; i++) //将MD5以16进制输出
40 cout<< hex <<(int)MD5result[i];
41 cout<<endl;
42 }while(false);
43
44 MD5((const unsigned char*)strFilePath.c_str(),strFilePath.size(),MD5result); //获取字符串MD5
45 cout<<"string MD5:"<<endl;
46 for(int i = 0; i < MD5LENTH; i++)
47 cout << hex << (int)MD5result[i];
48 cout<<endl;
49 return 0;
50 }
SConstruct:
Program('md5','md5.cpp',LIBS = ['ssl','crypto'])
测试结果与命令行比较: