Fairbanks FB3000 II Operators Manual - Manual (Page 62)

Appendix VII: SOCKS Information
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APPENDIX VII: SOCKS INFORMATION, CONTINUED
The SOCKS 5 Protocol, an extension of the SOCKS 4 Protocol that offers more
choices of authentication, is defined in RFC 1928.
The initial handshake now consists of the following:
• Client connects and sends a greeting which includes a list of authentication
methods supported.
• Server chooses one (or sends a failure response if none of the offered methods
are acceptable).
• Several messages may now pass between the client and the server depending on
the authentication method chosen.
• Client sends a connection request similar to SOCKS 4.
• Server responds similar to SOCKS 4.
The authentication methods supported are numbered as follows:
• 0x00 – No authentication.
• 0x01 – GSSAPI.
• 0x02 – Username/Password.
• 0x03-0x7F – Methods assigned by IANA.
• 0x80-0xFE – Methods reserved for private use.
The initial greeting from the client is:
• Field 1: SOCKS version number (must be 0x05 for this version).
• Field 2: Number of authentication methods supported, 1 byte.
• Field 3: Authentication methods, variable length, 1 byte per method supported.
The server’s choice is communicated:
• Field 1: SOCKS version, 1 byte (0x05 for this version).
• Field 2: Chosen authentication method, 1 byte, or 0xFF if no acceptable methods
were offered.