RFC 2941 (rfc2941) - Page 2 of 15

Telnet Authentication Option

RFC 2941              Telnet Authentication Option        September 2000


          KERBEROS_V5              2
          SPX*                     3
          MINK*                    4
          SRP                      5
          RSA*[also used by SRA*]  6
          SSL*                     7
          [unassigned]             8
          [unassigned]             9
          LOKI*                   10
          SSA*                    11
          KEA_SJ                  12
          KEA_SJ_INTEG            13
          DSS                     14
          NTLM*                   15

       Authentication types followed by (*) were never submitted to the
       IETF for consideration as an Internet standard.

       Following historical practice, future authentication type numbers
       and authentication modifiers will be assigned by the IANA under a
       First Come First Served policy as outlined by RFC 2434 [4].
       Despite the fact that authentication type numbers are allocated
       out of an 8-bit number space (as are most values in the telnet
       specification) it is not anticipated that the number space is or
       will become in danger of being exhausted.  However, if this
       should become an issue, when over 50% of the number space becomes
       allocated, the IANA shall refer allocation requests to either the
       IESG or a designated expert for approval.  IANA is instructed not
       to issue new suboption values without submission of documentation
       of their use.

          Modifiers
          AUTH_WHO_MASK        1
          AUTH_CLIENT_TO_SERVER    0
          AUTH_SERVER_TO_CLIENT    1

          AUTH_HOW_MASK        2
          AUTH_HOW_ONE_WAY         0
          AUTH_HOW_MUTUAL          2

          ENCRYPT_MASK        20
          ENCRYPT_OFF              0
          ENCRYPT_USING_TELOPT     4
          ENCRYPT_AFTER_EXCHANGE  16
          ENCRYPT_RESERVED        20

          INI_CRED_FWD_MASK    8
          INI_CRED_FWD_OFF         0



Ts'o & Altman               Standards Track