[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
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9 N) Q, t1 T! F# o" E) O正文
& _2 x: q9 }% L  U$ w3 Z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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! c* ^& B9 u$ w8 v+ G4 Q! N! b//使用到的结构
  Y* E+ m2 a5 K, U9 `: Mstruct sock4req1
; T; P9 I8 j8 Z' q" c! h& ~8 Y{
1 D9 l6 F6 L; \; ?char VN;
6 \- A! q3 O. K1 B1 y5 ?char CD;
unsigned short Port;
* `% z2 u+ \0 f6 K2 V: o3 e, k  {3 f: Xunsigned long IPAddr;
char other[1];
! p' }1 m3 D% Z9 e" P$ h" d};
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struct sock4ans1
{
char VN;
char CD;
};
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" P/ c8 d/ [0 x( }2 `4 ystruct sock5req1
( d, n3 C( c; f3 [6 [1 z/ I' N& J{
char Ver;
char nMethods;
' L5 R5 e7 z, ~2 G0 Rchar Methods[255];
; ~. I$ J! e2 c: e: o};
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struct sock5ans1
{
3 g. E/ q: j% K5 S6 Xchar Ver;
% U  B: O. y9 b( Pchar Method;
};
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struct sock5req2
2 C3 |- `) |$ y) h% C) p% B{
6 o) L6 d+ K/ G( o) c5 xchar Ver;
char Cmd;
char Rsv;
char Atyp;
char other[1];
};
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struct sock5ans2
- T8 S7 I! c0 k7 N{
char Ver;
char Rep;
7 [" I( g, A# ~7 d8 qchar Rsv;
) H4 x7 ^4 r  i1 S1 b; V9 m6 H. Kchar Atyp;
* h; z" D1 o2 s3 J6 M: m5 gchar other[1];
};
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struct authreq
{
char Ver;
char Ulen;
char Name[255];
7 n0 W/ P- {- P, Xchar PLen;
char Pass[255];
};
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struct authans
{
7 K% e: s! ?9 Y4 u* ]! B2 z6 Bchar Ver;
char Status;
};
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//通过Socks4方式代理
if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
5 K; s' L/ ]& [2 Q{
6 _: j0 M  M1 X( Mm_sError = _T("不能连接到代理服务器!");
ClientSock.Close();
return FALSE;
% A" n- {( {) w6 Q( v+ Y8 m3 e- {}
char buff[100];
5 J/ h7 _" A( T3 E# s- Q4 g0 umemset(buff,0,100);
+ S# X) f/ ]) N3 Bstruct sock4req1 *m_proxyreq;
m_proxyreq = (struct sock4req1 *)buff;
m_proxyreq->VN = 4;
m_proxyreq->CD = 1;
4 H, R: s5 m7 T5 dm_proxyreq-&gtort = ntohs(GetPort());
m_proxyreq->IPAddr = inet_addr(GetServerHostName());
ClientSock.Send(buff,9);
% ~3 F% g$ S. N3 Z8 jstruct sock4ans1 *m_proxyans;
7 g( D. s+ O5 j& X% nm_proxyans = (struct sock4ans1 *)buff;
memset(buff,0,100);
ClientSock.Receive(buff,100);
9 P. r0 [6 ^+ N, n) C5 B, aif(m_proxyans->VN != 0 || m_proxyans->CD != 90)
{
( @* k1 t9 C" j- l8 g) v; Dm_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
return FALSE;
}
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& A% a6 J1 Z* W1 X) X% h* Z( L1 C
//通过Socks5方式代理
- e1 h( j4 U" ^; z( hif( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
{
) n: {" G8 H2 s( Bm_sError = _T("不能连接到代理服务器!");
9 Z# X9 o8 n  }1 p% z7 BClientSock.Close();
return FALSE;
/ K+ Z" J$ ?' G( ^4 i}
char buff[600];
- Y5 l# s2 M( X* z: A% a  L8 v, dstruct sock5req1 *m_proxyreq1;
m_proxyreq1 = (struct sock5req1 *)buff;
m_proxyreq1->Ver = 5;
m_proxyreq1->nMethods = 2;
m_proxyreq1->Methods[0] = 0;
# ^- Q1 R, J8 Q4 b: Em_proxyreq1->Methods[1] = 2;
: M* h. M  o6 C! VClientSock.Send(buff,4);
struct sock5ans1 *m_proxyans1;
m_proxyans1 = (struct sock5ans1 *)buff;
memset(buff,0,600);
ClientSock.Receive(buff,600);
( H. t& e0 }- }7 \if(m_proxyans1->Ver != 5 || (m_proxyans1->Method!=0 && m_proxyans1->Method!=2))
{
m_sError = _T("通过代理连接主站不成功!");
4 S. j8 \7 D; a: l- WClientSock.Close();
return FALSE;
% D; Q2 W1 s( T. G+ a}
if(m_proxyans1->Method == 2)
{
int nUserLen = strlen(g_ProxyInfo.m_strProxyUser);
$ {& l$ O5 I2 }1 g' I' P- I; tint nPassLen = strlen(g_ProxyInfo.m_strProxyPass);
. ]# m7 W$ Q  n' ?struct authreq *m_authreq;
m_authreq = (struct authreq *)buff;
4 z& _  b" S9 G) Vm_authreq->Ver = 1;
5 |6 q3 q" s4 t' u  I7 s6 zm_authreq->Ulen = nUserLen;
. }# Z) V$ q8 d4 Z# X. I3 }( x0 jstrcpy(m_authreq->Name,g_ProxyInfo.m_strProxyUser);
m_authreq-&gtLen = nPassLen;
strcpy(m_authreq-&gtass,g_ProxyInfo.m_strProxyPass);
6 |4 v  X3 k, Q) `9 A9 JClientSock.Send(buff,513);
& N# z8 I% d, x8 W9 ^struct authans *m_authans;
m_authans = (struct authans *)buff;
memset(buff,0,600);
8 i5 b5 W: y) P5 I. AClientSock.Receive(buff,600);
. Z  R0 a. X/ r7 I8 p4 nif(m_authans->Ver != 1 || m_authans->Status != 0)
9 ~/ e4 x- `; r. M" w{
- d! E0 n/ `  i( _* Vm_sError = _T("代理服务器用户验证不成功!");
2 r) ?8 U  K! i. {1 t8 v+ EClientSock.Close();
7 K9 K# q& B9 j4 Dreturn FALSE;
' H2 l4 i, q  k, M, v, W) ?' i$ D6 c}
: J0 H  _: c$ Y( q. ?3 G}
struct sock5req2 *m_proxyreq2;
$ v( F+ W+ D" Q- O* c1 L: J) cm_proxyreq2 = (struct sock5req2 *)buff;
0 ?3 `# N% d9 V7 J# Vm_proxyreq2->Ver = 5;
5 C  O2 K1 i2 E; a, A: t6 p, Um_proxyreq2->Cmd = 1;
m_proxyreq2->Rsv = 0;
m_proxyreq2->Atyp = 1;
unsigned long tmpLong = inet_addr(GetServerHostName());
unsigned short port = ntohs(GetPort());
2 A7 v1 Z: b  D5 q' R) b% M" Kmemcpy(m_proxyreq2->other,&tmpLong,4);
memcpy(m_proxyreq2->other+4,&port,2);
ClientSock.Send(buff,sizeof(struct sock5req2)+5);
& i4 b' o/ A: s" [; Z$ ?! Istruct sock5ans2 *m_proxyans2;
" S' E, C/ i% a( Z6 o: Lmemset(buff,0,600);
2 f. j( f' S  Z2 h+ f( mm_proxyans2 = (struct sock5ans2 *)buff;
ClientSock.Receive(buff,600);
if(m_proxyans2->Ver != 5 || m_proxyans2->Rep != 0)
{
+ ?3 i- E4 u4 d* E$ \% U' ~2 K3 R( ^m_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
return FALSE;
}
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; j; x6 }! @+ n) R0 a//通过HTTP方式代理
, g" p. e3 ^1 H9 o4 T5 q8 sif( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
# g5 ]3 ^- K7 V. o0 k{
m_sError = _T("不能连接到代理服务器!");
3 Y0 |$ P! I4 P) F. LClientSock.Close();
$ ~- @# l4 s9 Treturn FALSE;
8 _* m8 \  X  G" o# v}
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");
ClientSock.Send(buff,strlen(buff)); //发送请求
+ X$ M+ x( j: w5 v/ ]( D  c6 dmemset(buff,0,600);
( o6 H5 Z7 H  O9 R6 V* ~ClientSock.Receive(buff,600);
0 W, j4 R' T1 O7 e8 P' \* s' gif(strstr(buff, "HTTP/1.0 200 Connection established") == NULL) //连接不成功
{
" G/ p. @8 M. jm_sError = _T("通过代理连接主站不成功!");
: f! N  O: |% x* d$ o0 y: OClientSock.Close();
; }7 ~3 U  e# a  Greturn FALSE;
}
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。