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socks5代理可以看rfc 1928
socks5的用户名口令认证方法看rfc 1929
http代理可以看 rfc2616
socks5代理可以支持tcp和udp 而http只支持tcp
所以这个代理转换器只支持tcp
写作原因
很多软件都有socks5认证方法 但是它们不支持http认证方法
而从原理上可以使用http认证方法(因为它们没有使用udp)
所以写这个软件可以方便的使其它程序可以使用http代理
如联众 或是foxmail
CODE
#include <winsock2.h>
#include <stdio.h>
#include <stdlib.h>
#define INIT_SOCKET(){WSADATA wsadata;WSAStartup(MAKEWORD(2,2),&wsadata);}
#define CLOSESOCKET(x) closesocket(x)
#define CLEAN_SOCKET() {WSACleanup();}
// http.c 实现http代理功能
#define PROTO_EXCHANGE_TIMEOUT 15
#define PROTO_RECVRESP_TIMEOUT 75
#define PROTO_SENDRESP_TIMEOUT 10
#define WAIT_AND_RECV(sd,buf,len,waittime,recvflags) do{\
struct fd_set sset;\
struct timeval waited;\
waited.tv_sec = waittime;waited.tv_usec = 0;\
FD_ZERO(&sset);FD_SET(sd,&sset);\
if(select(sd+1,&sset,NULL,NULL,&waited) != 1 || (len = recv(sd,buf,len,recvflags)) == -1 )\
len = -1;\
}while(0);
#define DEBUG_DUMP printf
static int httpproxy_connect(const char*proxyaddr,int proxyport,
const char*dstaddr,int dstport)
{
int proxysd = -1;
char buf[2048];
int len;
char *ptoken;
int status;
struct sockaddr_in inaddr;
if( !proxyaddr || !proxyaddr[0] || proxyport < 1
||!dstaddr || !dstaddr[0] )
return -1;
DEBUG_DUMP("代理:%s:%d,目标:%s:%d\n",proxyaddr,proxyport,dstaddr,dstport);
len = sizeof(inaddr);
memset(&inaddr,0,len);
if( (inaddr.sin_addr.s_addr = inet_addr(proxyaddr) ) == INADDR_NONE )
return -1;
inaddr.sin_family = AF_INET;
inaddr.sin_port = htons(proxyport);
// connect to proxy
if((proxysd = socket(AF_INET,SOCK_STREAM,0)) == -1 )
return -1;
if( connect(proxysd,(struct sockaddr*)&inaddr,len))
goto errorparse;
// 发送connect请求并判断返回,根据HTTP协议说明,详细内容请看RFC2616
// HTTP代理使用CONNECT指令实现，CONNECT时指定选端的地址与端口号,
// 当代理服务器返回成功后(状态值是2xx),后面的代理服务器不再对此连接的数据
// 进行HTTP协议处理
if( dstport > 0 )
len = sprintf(buf,"CONNECT %s:%d HTTP/1.1\r\n\r\n",dstaddr,dstport);
else
len = sprintf(buf,"CONNECT %s HTTP/1.1\r\n\r\n",dstaddr);
if( send(proxysd,buf,len,0) != len ){
DEBUG_DUMP("发送CONNECT请求失败:包内容:%s\n",buf);
goto errorparse;
}
len = sizeof(buf)-1;
WAIT_AND_RECV(proxysd,buf,len,PROTO_RECVRESP_TIMEOUT,MSG_PEEK);
if( len == -1){
DEBUG_DUMP("接收CONNECT响应失败\n");
goto errorparse;
}
buf[len] = 0;
DEBUG_DUMP("CONNECT响应为:%s|\n",buf);
if( strnicmp(buf,"HTTP/1.",7)
|| (!strstr(buf,"\r\n\r\n") && !strstr(buf,"\n\n")))
goto errorparse;
ptoken = buf;
while(!isspace(*ptoken) && *ptoken) ptoken ++;
status = atoi(ptoken);
if( status < 300 && status > 199 ){
ptoken = strstr(buf,"\r\n\r\n");
if( ptoken )
len = ptoken - buf +4;
else{
ptoken = strstr(buf,"\n\n");
len = ptoken - buf +2;
}
WAIT_AND_RECV(proxysd,buf,len,PROTO_RECVRESP_TIMEOUT,0);
return proxysd;
}
errorparse:
CLOSESOCKET(proxysd);
return -1;
}
// sd [in] 使用socks5的客户端的连接id
// proxyaddr [in] http代理地址
// proxyport [in] http代理端口
// return:
// -1 失败
// >=0 与http代理的连接id
static int socks5_accept(int sd,const char *proxyaddr,int proxyport)
{
unsigned char buf[512];
int len = 2;
int i = 0;
char dstaddr[260];
int dstport;
if( !proxyaddr || !proxyaddr[0] || proxyport <1 )
return -1;
// 处理协商,现在只处理无认证情况,无论对方会不会处理这种情况
// 没有要求无认证方式,sorry,那我就不理它
// 另外只处理SOCKS5的CONNECT命令,其它不处理
WAIT_AND_RECV(sd,(char*)buf,len,PROTO_EXCHANGE_TIMEOUT,0);
if( len != 2 || buf[0] != 5 ){
DEBUG_DUMP("接收socks5协商包失败,len:%d,buf[0]:%d\n",len,buf[0]);
return -1;
}
len = buf[1];
i = len;
WAIT_AND_RECV(sd,(char*)buf,i,PROTO_EXCHANGE_TIMEOUT,0);
if( len != i ){
DEBUG_DUMP("接收socks5协商包失败,想接收%d,收到:%d\n",len,i);
return -1;
}
for( i = 0;i< len && buf[i];i++ );
if( i == len ){
DEBUG_DUMP("用户没有请求socks5无认证方法:\n");
return -1;
}
buf[0] = 5;
buf[1] = 0;
if( send(sd,(char*)buf,2,0) != 2)
return -1;
len = 5;
WAIT_AND_RECV(sd,(char*)buf,len,PROTO_RECVRESP_TIMEOUT,0);
if( len != 5 || buf[0] != 5 || buf[1] != 1 ){
DEBUG_DUMP("处理socks5CONNECT命令失败:len:%d,buf[0]:0x%x,buf[1]:0x%x\n",len,buf[0],buf[1]);
return -1;
}
switch( buf[3] ){
case 1: // 是IP地址
len = 5;
WAIT_AND_RECV(sd,(char*)buf+5,len,PROTO_RECVRESP_TIMEOUT,0);
if( len != 5 ){
DEBUG_DUMP("处理socks5CONNECT命令[IP方式]失败:len:%d\n",len);
return -1;
}
{
struct in_addr addr;
memcpy((char*)&addr.s_addr,buf+4,4);
strcpy(dstaddr,inet_ntoa(addr));
dstport = ntohs(*(unsigned short*)(buf+8));
}
break;
case 3: // 是域方式
len = buf[4]+2;
WAIT_AND_RECV(sd,(char*)buf+5,len,PROTO_RECVRESP_TIMEOUT,0);
if( len != buf[4]+2 ){
DEBUG_DUMP("处理socks5CONNECT命令[域方式]失败:len:%d\n",len);
return -1;
}
memcpy(dstaddr,buf+5,buf[4]);
dstaddr[buf[4]] = 0;
dstport = ntohs(*(unsigned short*)(buf+5+buf[4]));
break;
default:
DEBUG_DUMP("处理socks5CONNECT命令[]失败:未知方式:type:0x%x\n",buf[3]);
return -1;
}
return httpproxy_connect(proxyaddr,proxyport,dstaddr,dstport);
}
int listenport(int port,const char*addr)
{
int len = sizeof(struct sockaddr_in);
struct sockaddr_in bindaddr;
int sd = socket(AF_INET,SOCK_STREAM,0);
if( sd == -1)
return -1;
memset(&bindaddr,0,len);
bindaddr.sin_family = AF_INET;
bindaddr.sin_port = htons(port);
if( addr && addr[0] )
bindaddr.sin_addr.s_addr = inet_addr(addr);
if( bind ( sd,(struct sockaddr*)&bindaddr,&len) || listen(sd,100 )){
DEBUG_DUMP("打开端口失败,port:%d\n",port);
CLOSESOCKET(sd);
return -1;
}
return sd;
}
void running(int sd){
int ad;
if( sd == -1 )
return;
while(1){
int proxyid;
char buf[10240];
int len;
int maxid;
int actcount;
ad = accept(sd,NULL,NULL);
if( ad == -1 )
break;
DEBUG_DUMP("有客户连接,id:%d\n",ad);
if((proxyid = socks5_accept(ad,"172.16.68.21",80)) == -1 ){
CLOSESOCKET(ad);
continue;
}
// 进行代理转发工作
maxid = ad > proxyid? ad:proxyid;
while( ad > -1 ){
struct timeval waittime = {10,0};
struct fd_set sset;
FD_ZERO(&sset);
FD_SET(ad,&sset);
FD_SET(proxyid,&sset);
actcount = select(maxid+1,&sset,NULL,NULL,&waittime);
while(actcount > 0 ){
int actid = FD_ISSET(proxyid,&sset)?proxyid:ad;
int sendid = actid == ad? proxyid:ad;
FD_CLR(actid,&sset);
len = sizeof(buf)-1;
WAIT_AND_RECV(actid,buf,len,10,0);
if( len > 0 ){
buf[len] = 0;
send(sendid,buf,len,0);
DEBUG_DUMP("%d接口活动,内容为:%s\n",actid,buf);
}
else{
DEBUG_DUMP("接收失败,id:%d\n",actid);
CLOSESOCKET(ad);
ad = -1;
break;
}
actcount --;
}
}
// 某一方已经关闭,继续下一组转发
CLOSESOCKET(proxyid);
}
CLOSESOCKET(sd);
}
main(){
int ld;
INIT_SOCKET();
ld = listenport(1080,NULL);
if( ld != -1)
running(ld);
else
DEBUG_DUMP("监听失败\n");
CLEAN_SOCKET();
}
http及socks5代理只是在CONNECT时进行协商
后面的操作不需要附加的信息
同时代理也不会对数据进行解释 只是进行转发
这只是一个测试程序
可以自己使用httpproxy_connect与socks5_accept来实现自己的代理转换程序
另外在flashfxp上测试成功
在foxmail上还没有测试成功
主要函数说明
httpproxy_connect
通过http代理创建到目标机器的连接
socks5_accept
接收socks5连接请求,并把它转换成http代理,
创建http代理通道成功后返回http代理通道的socketid
以上两个失败都返回-1
创建成功后
客户端 <-数据-->socks5 sd <---数据--->http proxy sd<---->目标 
OVER
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