[收藏]穿透代理服务器编程

天云上人

  作者 allfresh
* t4 {+ R9 F+ X7 p0 O+ h2 W% D文章原始出处 www.allfresh.net/program/proxy.htm
wwww.chin aitpower.comJZM2iofLWRmFIxU68q4I3qxHU
; Z  q+ A5 ]/ U! C正文
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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, j/ ~; v9 V/ \" K. Y8 a//使用到的结构
struct sock4req1
4 K1 M) Y& {: b# d2 k! M{
char VN;
4 \  N) J# Z8 {- \5 ~1 Kchar CD;
! I9 _8 p, v' ]3 Kunsigned short Port;
unsigned long IPAddr;
& [+ F0 R5 b/ W" p. `6 b- vchar other[1];
};
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struct sock4ans1
{
char VN;
: Z7 k, Q5 M5 p/ S; w& w0 \char CD;
};
+ K5 T' b0 U  q- }* {* n8 A* mwwww.chin aitpower.comJZM2iofLWRmFIxU68q4I3qxHU
, n7 m/ ^  V2 L; ]- M) @( Bstruct sock5req1
{
4 x2 ?# v) b/ H. V% `% A$ tchar Ver;
3 H9 f# `9 |( ]' ^( G9 L" ]char nMethods;
# q) j, L# Q7 F/ A# y; W' A" P1 l' y. echar Methods[255];
) |. d8 |, v" @3 O- t- i  Y};
3 x( b! L; b& C3 Awwww.chin aitpower.comJZM2iofLWRmFIxU68q4I3qxHU
struct sock5ans1
3 E1 o+ k% C6 E  S0 M{
char Ver;
char Method;
};
wwww.chin aitpower.comJZM2iofLWRmFIxU68q4I3qxHU
struct sock5req2
{
" J$ P4 X, t1 e6 T& y, `char Ver;
0 z$ ]# a8 d# Q( `+ ?- K& `char Cmd;
+ G/ v/ a' l  d" [! b3 _1 I% |char Rsv;
char Atyp;
char other[1];
, g/ J- h/ c$ J/ h6 U};
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4 L$ l4 V% I( u1 D7 T, l% qstruct sock5ans2
{
char Ver;
char Rep;
; R  J- I, Q: [/ Y7 }# a5 e  {, Lchar Rsv;
! l5 J( i# @; K( s) e7 Pchar Atyp;
( X8 ?5 J7 E  Hchar other[1];
};
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+ Q# d# F* r; t' qstruct authreq
  U- D, A% I# @0 Y' x* G9 G{
char Ver;
char Ulen;
char Name[255];
, J9 ]8 y: D4 Nchar PLen;
char Pass[255];
};
( E& \8 f3 l# |8 J- h2 Ywwww.chin aitpower.comJZM2iofLWRmFIxU68q4I3qxHU
. s8 ?* ^# J1 Y2 V! y4 o+ U% [2 }$ xstruct authans
+ b$ ]0 k; |  h& t, v* T( {! M{
char Ver;
char Status;
& l# A4 Y/ X1 |( n6 E% U};
/ n+ y& Z2 S" V( q( qwwww.chin aitpower.comJZM2iofLWRmFIxU68q4I3qxHU
//通过Socks4方式代理
  u, d# j/ g' a9 U3 Tif( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
{
2 x( J" \) Y" z4 F& |m_sError = _T("不能连接到代理服务器!");
# V% n$ a% \3 H6 I/ eClientSock.Close();
; D, Y9 C2 C2 E7 }. qreturn FALSE;
}
char buff[100];
5 \7 p) x$ G1 u6 G7 f1 K; Mmemset(buff,0,100);
struct sock4req1 *m_proxyreq;
m_proxyreq = (struct sock4req1 *)buff;
' M" s, }  h+ E/ C* Rm_proxyreq->VN = 4;
# v. f' L) y9 ^6 Q) u+ K6 U+ fm_proxyreq->CD = 1;
( Z. f; R; O) m4 y" g$ g' Am_proxyreq-&gtort = ntohs(GetPort());
4 @. I  S( W+ E) I7 ~m_proxyreq->IPAddr = inet_addr(GetServerHostName());
' C9 h3 z( w7 F/ zClientSock.Send(buff,9);
struct sock4ans1 *m_proxyans;
m_proxyans = (struct sock4ans1 *)buff;
memset(buff,0,100);
ClientSock.Receive(buff,100);
1 ]& U' [, L2 g0 e4 m" Oif(m_proxyans->VN != 0 || m_proxyans->CD != 90)
{
) x  L6 a/ I, x6 C$ p/ ^. E' A: ~m_sError = _T("通过代理连接主站不成功!");
/ }$ h. ?$ i% f8 `9 gClientSock.Close();
return FALSE;
+ C$ Y. j( G. H0 a( R' f$ }0 p}
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& A7 q. l  k4 a  uwwww.chin aitpower.comJZM2iofLWRmFIxU68q4I3qxHU

+ n+ Z1 x, {  V& b//通过Socks5方式代理
if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
{
# |5 \5 G/ h; V6 r% V& bm_sError = _T("不能连接到代理服务器!");
ClientSock.Close();
return FALSE;
* D4 f+ V/ {3 L! ?}
2 F! j- R' l7 M$ D3 C, @1 dchar buff[600];
struct sock5req1 *m_proxyreq1;
m_proxyreq1 = (struct sock5req1 *)buff;
. n7 R' r% a7 U0 T. g9 ym_proxyreq1->Ver = 5;
m_proxyreq1->nMethods = 2;
, g8 Z4 B2 |. _* Km_proxyreq1->Methods[0] = 0;
9 K& X6 J5 m7 Fm_proxyreq1->Methods[1] = 2;
/ `- E: E2 @* |$ tClientSock.Send(buff,4);
struct sock5ans1 *m_proxyans1;
' p8 c. A6 X: om_proxyans1 = (struct sock5ans1 *)buff;
5 ~2 u$ d3 U8 d9 Amemset(buff,0,600);
8 L6 j7 p; J9 U( |) w4 xClientSock.Receive(buff,600);
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!");
% q4 s4 Q% [4 t- r) \0 ^5 oClientSock.Close();
return FALSE;
4 y- f$ b  k5 c, e: o+ C8 d" |) |}
: w/ i% j( R+ o9 v* r+ |if(m_proxyans1->Method == 2)
0 W6 b- Y, N: R% Y( c- G{
" y( N5 A6 |9 Q$ aint nUserLen = strlen(g_ProxyInfo.m_strProxyUser);
int nPassLen = strlen(g_ProxyInfo.m_strProxyPass);
3 ^9 ?. {- i; l: n  G0 {struct authreq *m_authreq;
m_authreq = (struct authreq *)buff;
m_authreq->Ver = 1;
6 \8 _! G5 m0 ?0 Tm_authreq->Ulen = nUserLen;
  d: p: D1 t5 j7 ?( C9 a! j- Lstrcpy(m_authreq->Name,g_ProxyInfo.m_strProxyUser);
m_authreq-&gtLen = nPassLen;
# b" G( A* d& x: p/ L! W+ X/ fstrcpy(m_authreq-&gtass,g_ProxyInfo.m_strProxyPass);
ClientSock.Send(buff,513);
struct authans *m_authans;
& A- N/ A/ t! U. Im_authans = (struct authans *)buff;
# K" |- e7 L4 K4 B5 j2 q' R4 umemset(buff,0,600);
ClientSock.Receive(buff,600);
' x& l- a9 j, A- v2 }! \! Cif(m_authans->Ver != 1 || m_authans->Status != 0)
. o$ u# p8 D: K0 n0 j{
m_sError = _T("代理服务器用户验证不成功!");
" o3 F( d6 ]& n- ^ClientSock.Close();
: r5 w6 {+ H, Q( S0 w  O- e# yreturn FALSE;
}
% p* m# I9 j7 D! r! c}
struct sock5req2 *m_proxyreq2;
m_proxyreq2 = (struct sock5req2 *)buff;
0 F( W, y6 e0 F% Om_proxyreq2->Ver = 5;
m_proxyreq2->Cmd = 1;
" s: p+ ~* ?3 W8 W0 Qm_proxyreq2->Rsv = 0;
m_proxyreq2->Atyp = 1;
* l' k+ `4 m. bunsigned long tmpLong = inet_addr(GetServerHostName());
0 w/ u* {  K  V- Punsigned short port = ntohs(GetPort());
. c2 ~( f9 ]2 b7 M0 @( z& nmemcpy(m_proxyreq2->other,&tmpLong,4);
& W( ?! o! U4 x  Y" `memcpy(m_proxyreq2->other+4,&port,2);
+ i- U- ^) g% i, y" kClientSock.Send(buff,sizeof(struct sock5req2)+5);
$ B/ M+ H+ E% K0 ?+ Wstruct sock5ans2 *m_proxyans2;
$ C" @8 J& a' ]+ x1 L. K% ymemset(buff,0,600);
m_proxyans2 = (struct sock5ans2 *)buff;
# D6 Q& i8 d. e4 h3 V" }" i* _3 S, Y: OClientSock.Receive(buff,600);
if(m_proxyans2->Ver != 5 || m_proxyans2->Rep != 0)
{
m_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
6 w; U/ m8 R8 v/ D; mreturn FALSE;
}
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3 X* V1 f, R, ^, V0 T0 Ewwww.chin aitpower.comJZM2iofLWRmFIxU68q4I3qxHU
' R; \$ U1 h) O
8 i* I5 K7 j4 q4 i( i1 t//通过HTTP方式代理
if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
{
m_sError = _T("不能连接到代理服务器!");
ClientSock.Close();
return FALSE;
}
* f' J% W& }1 X, N( O6 H: Echar 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
5 D8 i: f4 u: S) ~memset(buff,0,600);
ClientSock.Receive(buff,600);
if(strstr(buff, "HTTP/1.0 200 Connection established") == NULL) //连接不成功
) t8 F4 ?, F+ K5 H4 h9 W8 R{
, M3 Z% L% V0 ~8 um_sError = _T("通过代理连接主站不成功!");
' H( g/ k# Q0 oClientSock.Close();
! x* ^* K' E3 l. z& \0 D+ A; Nreturn FALSE;
}
( m) ^  p7 z- H* @. n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。