[收藏]穿透代理服务器编程

天云上人

  作者 allfresh
文章原始出处 www.allfresh.net/program/proxy.htm
wwww.chin aitpower.comJZM2iofLWRmFIxU68q4I3qxHU
  ~) c- N. _" U) t正文
: s0 T( v. l7 |5 f2 n0 R* f* v在网络程序设计过程中，我们经常要与各种类型的代理服务器打交道，比如在企业内部网通过代理去访问Internet网上的服务器等等，一般代理服务器支持几种常见的代理协议标准，如Socks4,Socks5,Http代理，其中Socks5需要用户验证，代理相对复杂。我在查阅RFC文档和相关资料后，特总结一些TCP协议穿透代理服务器的程序片断，希望对大家有所帮助。
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//使用到的结构
struct sock4req1
9 ]) E1 c  B- D, s8 T7 S+ N  Q{
char VN;
0 C3 A" c2 W# D7 Y/ @: Rchar CD;
unsigned short Port;
( t: l' @/ R. Q  q* B  [unsigned long IPAddr;
char other[1];
};
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struct sock4ans1
{
1 {0 e+ O( ^) k$ |) Y5 N& Lchar VN;
char CD;
};
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, n3 _/ E$ U1 E  {7 q; G3 J: Istruct sock5req1
{
char Ver;
char nMethods;
char Methods[255];
; b7 ~" K( X% o% n. P};
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: l7 g& ?/ I4 ^0 [9 e' hstruct sock5ans1
' @+ z7 B- {) U" T% D: I  E{
char Ver;
3 m) k% q8 `' J& xchar Method;
};
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4 V. {7 J9 X6 u, p9 Z* A/ sstruct sock5req2
{
char Ver;
- u. v) i! T1 j: Ochar Cmd;
6 ?; O" x4 s8 L5 s; U: J3 {- Achar Rsv;
% N/ p5 ?, F9 wchar Atyp;
; {8 `  n* y% A" `char other[1];
; o' |/ N0 l8 ?6 y; h# c5 J- [, @};
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; y. `$ O+ [7 R& I  pstruct sock5ans2
{
char Ver;
, G9 e# d9 T! u% ]# _! s: Vchar Rep;
1 n; Z$ L8 O2 i+ k, P% bchar Rsv;
1 Y5 b8 H& B9 w. k3 w/ y+ schar Atyp;
  A; m) d; l$ u) a6 Dchar other[1];
};
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struct authreq
{
char Ver;
char Ulen;
char Name[255];
char PLen;
' D2 A; y4 q, Z% t) q, Xchar Pass[255];
7 x0 U8 V5 n4 W( q};
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- g% c; Q! D9 r1 nstruct authans
. p* l* k# f  Q2 U5 h$ b{
, j5 h0 A/ y( P8 ]5 J7 C* _char Ver;
char Status;
$ N1 l( J4 u# e! v};
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//通过Socks4方式代理
if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
{
8 z3 }( L9 ~' K8 {( w8 z' B4 [m_sError = _T("不能连接到代理服务器!");
ClientSock.Close();
return FALSE;
( R4 J+ a, \5 I- U8 H( ]9 m) F}
: e* C/ @6 m- E) [; `char buff[100];
memset(buff,0,100);
struct sock4req1 *m_proxyreq;
8 N. z/ A( X' ~7 I2 L. [- Dm_proxyreq = (struct sock4req1 *)buff;
: I% S/ @. n' _) S$ Um_proxyreq->VN = 4;
; Q, M9 f( V, v2 _7 n4 f( Am_proxyreq->CD = 1;
m_proxyreq-&gtort = ntohs(GetPort());
m_proxyreq->IPAddr = inet_addr(GetServerHostName());
  a8 c1 R0 I6 J1 UClientSock.Send(buff,9);
struct sock4ans1 *m_proxyans;
m_proxyans = (struct sock4ans1 *)buff;
memset(buff,0,100);
! R) ]  [# O$ H. sClientSock.Receive(buff,100);
if(m_proxyans->VN != 0 || m_proxyans->CD != 90)
{
m_sError = _T("通过代理连接主站不成功!");
' J1 y- z0 b6 }# b# Q1 {0 xClientSock.Close();
return FALSE;
8 k! d8 f8 k% B7 Q}
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//通过Socks5方式代理
5 T8 F% O( s( r' ?% e6 B1 v  |; a3 yif( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
9 b" ~4 W% I# w. L+ _9 n8 {{
m_sError = _T("不能连接到代理服务器!");
2 M" ~6 r$ C, x* hClientSock.Close();
return FALSE;
& C; t2 w4 v( e3 K}
char buff[600];
% B& G( F& ?$ r' kstruct sock5req1 *m_proxyreq1;
m_proxyreq1 = (struct sock5req1 *)buff;
5 U, T* p% O7 V8 I8 t7 ^m_proxyreq1->Ver = 5;
  U; _* J- F  L% `$ ]; Jm_proxyreq1->nMethods = 2;
( W: P/ q: x4 W, Fm_proxyreq1->Methods[0] = 0;
/ Q0 f/ w$ M1 W+ }) [6 em_proxyreq1->Methods[1] = 2;
ClientSock.Send(buff,4);
struct sock5ans1 *m_proxyans1;
m_proxyans1 = (struct sock5ans1 *)buff;
$ A6 T' M& Y5 G9 a9 o5 [memset(buff,0,600);
ClientSock.Receive(buff,600);
8 {; X. N; T" Y( }6 h0 r. m4 ~/ Zif(m_proxyans1->Ver != 5 || (m_proxyans1->Method!=0 && m_proxyans1->Method!=2))
6 @3 S# H( s# _& x{
( @  T3 O- V" P0 h( a+ _m_sError = _T("通过代理连接主站不成功!");
  [  S0 L9 c- h" ~$ \ClientSock.Close();
6 J+ c6 Y% q- [2 y1 Zreturn FALSE;
* u: P- O9 P5 _1 W6 s: D4 P}
% i! n9 ^4 r4 n7 h# qif(m_proxyans1->Method == 2)
; Z; @: U, p" m{
int nUserLen = strlen(g_ProxyInfo.m_strProxyUser);
int nPassLen = strlen(g_ProxyInfo.m_strProxyPass);
. j# k0 Z+ s/ J/ v# w+ xstruct authreq *m_authreq;
m_authreq = (struct authreq *)buff;
m_authreq->Ver = 1;
m_authreq->Ulen = nUserLen;
/ k) M. C2 N5 G- q( q( }strcpy(m_authreq->Name,g_ProxyInfo.m_strProxyUser);
5 g2 h, c" e# L6 @' \m_authreq-&gtLen = nPassLen;
strcpy(m_authreq-&gtass,g_ProxyInfo.m_strProxyPass);
ClientSock.Send(buff,513);
8 t3 P+ z, R& E. [. B7 pstruct authans *m_authans;
* y* i/ m2 ?5 D2 ]+ x8 Qm_authans = (struct authans *)buff;
5 B1 W1 a1 I- t& D. Pmemset(buff,0,600);
( K/ g  F0 f$ S! k9 }6 lClientSock.Receive(buff,600);
if(m_authans->Ver != 1 || m_authans->Status != 0)
{
m_sError = _T("代理服务器用户验证不成功!");
- {; e( P$ i0 y. u7 d; e9 i$ KClientSock.Close();
return FALSE;
3 W3 R1 W6 `: @- K/ E+ `}
}
struct sock5req2 *m_proxyreq2;
( k! L( n1 G, u2 H" y1 s$ ?6 Qm_proxyreq2 = (struct sock5req2 *)buff;
m_proxyreq2->Ver = 5;
) R0 z. ]1 }* Q5 Gm_proxyreq2->Cmd = 1;
m_proxyreq2->Rsv = 0;
1 ]% J3 Y: a- N* km_proxyreq2->Atyp = 1;
unsigned long tmpLong = inet_addr(GetServerHostName());
6 t( W1 \3 v9 B% O& Z' D6 Iunsigned short port = ntohs(GetPort());
memcpy(m_proxyreq2->other,&tmpLong,4);
memcpy(m_proxyreq2->other+4,&port,2);
! x. q$ m& ?  b* Z. n! ]( zClientSock.Send(buff,sizeof(struct sock5req2)+5);
. G$ V* ^5 R" f% [8 l# estruct sock5ans2 *m_proxyans2;
# j4 ]8 ]- h3 @5 N6 vmemset(buff,0,600);
3 w6 }* g$ o" n2 Ym_proxyans2 = (struct sock5ans2 *)buff;
ClientSock.Receive(buff,600);
- n3 i. Q1 h  k4 y9 ^8 A0 cif(m_proxyans2->Ver != 5 || m_proxyans2->Rep != 0)
{
m_sError = _T("通过代理连接主站不成功!");
- @: t& ^8 A- x0 ^6 ?" _ClientSock.Close();
! d% Q+ S, h. @1 D1 `return FALSE;
}
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4 P7 T% \$ t' d' N" X
//通过HTTP方式代理
! m  v2 K* E8 s1 t/ xif( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
{
7 C# |/ u" a! W$ c2 W# Um_sError = _T("不能连接到代理服务器!");
ClientSock.Close();
* E  ]- ~. z% ureturn FALSE;
- m7 f! I1 f- O}
char buff[600];
sprintf( buff, "%s%s:%d%s","CONNECT ",GetServerHostName(),GetPort()," HTTP/1.1\r\nUser-Agent: MyApp/0.1\r\n\r\n");
/ b/ p9 y) }4 lClientSock.Send(buff,strlen(buff)); //发送请求
/ L4 P: K$ ^. ?4 L, {2 Z6 I( fmemset(buff,0,600);
ClientSock.Receive(buff,600);
if(strstr(buff, "HTTP/1.0 200 Connection established") == NULL) //连接不成功
{
m_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
return FALSE;
. V3 B$ _( C, i}
4 G% I! d6 ?' u我们一般先与代理服务器连通，然后向代理服务器发送代理验证的用户名和密码(如果需要,如Socks5代理)，验证成功后，再向代理服务器发送需要连接的目的地址和端口。以上代码仅用于TCP连接，如果在内部网侦听或通过UDP协议发送信息，可查阅RFC1829等文档资料。