VB6中使用Winsock穿越各种代理的实现

　　最后,接受服务器返回数据,看RFC:

　　+----+-----+-------+------+----------+----------+

　　|VER | REP | RSV | ATYP | BND.ADDR | BND.PORT |

　　+----+-----+-------+------+----------+----------+

　　| 1 | 1 | X'00' | 1 | Variable | 2 |

　　+----+-----+-------+------+----------+----------+

　　Where:

　　o VER protocol version: X'05' ------------ 固定 05

　　o REP Reply field:

　　o X'00' succeeded ------------ 若为 00 成功 其余可以都看成失败

　　o X'01' general SOCKS server failure

　　o X'02' connection not allowed by ruleset

　　o X'03' Network unreachable

　　o X'04' Host unreachable

　　o X'05' Connection refused

　　o X'06' TTL expired

　　o X'07' Command not supported

　　o X'08' Address type not supported

　　o X'09' to X'FF' unassigned

　　o RSV RESERVED

　　o ATYP address type of following address

　　o IP V4 address: X'01'

　　o DOMAINNAME: X'03'

　　o IP V6 address: X'04'

　　o BND.ADDR server bound address

　　o BND.PORT server bound port in network octet order

　　Fields marked RESERVED (RSV) must be set to X'00'.

　　可见,对于返回信息,只须判断第二字节是否为00.若为 00 连接成功,剩下的操作和直连一样,Winsock可直接用SendData 和 GetData 发送\接受数据.

　　下面介绍需要验证用户名/密码的socks5穿透

　　第一步还是发送三个字节,只是内容有变,展开来写为: 05 01 02

　　服务器返回信息也有所不同,正确的返回为 05 02

　　成功后发送用户/密码信息,请看RFC 说明:

　　Once the SOCKS V5 server has started, and the client has selected the

　　Username/Password Authentication protocol, the Username/Password

　　subnegotiation begins. This begins with the client producing a

　　Username/Password request:

　　+----+------+----------+------+----------+

　　|VER | ULEN | UNAME | PLEN | PASSWD |

　　+----+------+----------+------+----------+

　　| 1 | 1 | 1 to 255 | 1 | 1 to 255 |

　　+----+------+----------+------+----------+

　　The VER field contains the current version of the subnegotiation,

　　which is X'01'. The ULEN field contains the length of the UNAME field

　　that follows. The UNAME field contains the username as known to the

　　source operating system. The PLEN field contains the length of the

　　PASSWD field that follows. The PASSWD field contains the password

　　association with the given UNAME.

　　The server verifies the supplied UNAME and PASSWD, and sends the

　　following response:

　　+----+--------+

　　|VER | STATUS |

　　+----+--------+

　　| 1 | 1 |

　　+----+--------+

　　A STATUS field of X'00' indicates success. If the server returns a

　　`failure' (STATUS value other than X'00') status, it MUST close the

　　connection.