VB6中使用Winsock穿越各种代理的实现(五)

　　根据RFC的说法,代理服务器返回8字节的数据,我们只要判断第二字节是否为90即可,若是90连接成功,否则失败.剩下的操作和直连一样,Winsock可直接用SendData 和 GetData 发送\接受数据.

　　HTTP1.1 代理的穿透

　　由于RFC 2616过于冗长,加上HTTP代理穿透的步骤比socks简单,这里就不详细说明了,我只给出连接的步骤和发送数据格式.

　　第一步仍然是用Winsock去连接代理服务器.第二步为发送请求字符,其格式为:

　　无用户名/密码校验 格式:

　　"CONNECT" + 空格 + 目标连接地址 + ":" + 目标连接端口 + 空格 + "HTTP/1.1" + Chr(13) + Chr(10) + "Host:" + 空格 + 目标连接地址 + ":" + 目标连接端口 + Chr(13) + Chr(10) + Chr(13) + Chr(10)

　　用户名/密码验证格式:

　　"CONNECT" + 空格 + 目标连接地址 + ":" + 目标连接端口 + 空格 + "HTTP/1.1" + Chr(13) + Chr(10) + "Host:" + 空格 + 目标连接地址 + ":" + 目标连接端口 + Chr(13) + Chr(10) + "Authorization: Basic" + 空格 + 经Base64加密过后的[用户名:密码] + Chr(13) + Chr(10) + Chr(13) + Chr(10) + "Proxy-Authorization: Basic" + 空格 + 经Base64加密过后的[用户名:密码] + Chr(13) + Chr(10) + Chr(13) + Chr(10)

发送请求完毕后,将收到代理的回应,根据RFC说明(注意 Status-Line 和 Status-Code):

　　6 Response

　　After receiving and interpreting a request message, a server responds

　　with an HTTP response message.

　　Response = Status-Line ; Section 6.1

　　*(( general-header ; Section 4.5

　　| response-header ; Section 6.2

　　| entity-header ) CRLF) ; Section 7.1

　　CRLF

　　[ message-body ] ; Section 7.2

　　6.1 Status-Line

　　The first line of a Response message is the Status-Line, consisting

　　of the protocol version followed by a numeric status code and its

　　associated textual phrase, with each element separated by SP

　　characters. No CR or LF is allowed except in the final CRLF sequence.

　　Status-Line = HTTP-Version SP Status-Code SP Reason-Phrase CRLF

　　6.1.1 Status Code and Reason Phrase

　　The Status-Code element is a 3-digit integer result code of the

　　attempt to understand and satisfy the request. These codes are fully

　　defined in section 10. The Reason-Phrase is intended to give a short

　　textual description of the Status-Code. The Status-Code is intended

　　for use by automata and the Reason-Phrase is intended for the human

　　user. The client is not required to examine or display the Reason-

　　Phrase.

　　The first digit of the Status-Code defines the class of response. The

　　last two digits do not have any categorization role. There are 5

　　values for the first digit:

　　- 1xx: Informational - Request received, continuing process

　　- 2xx: Success - The action was successfully received,

　　understood, and accepted

　　- 3xx: Redirection - Further action must be taken in order to

　　complete the request

　　- 4xx: Client Error - The request contains bad syntax or cannot

　　be fulfilled

　　- 5xx: Server Error - The server failed to fulfill an apparently

　　valid request

　　The individual values of the numeric status codes defined for

　　HTTP/1.1, and an example set of corresponding Reason-Phrase's, are

　　presented below. The reason phrases listed here are only

　　recommendations -- they MAY be replaced by local equivalents without

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