RFC 2941 (rfc2941) - Page 2 of 15
Telnet Authentication Option
Alternative Format: Original Text Document
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