Canon Color Network UFR Printer Kit-C1, Руководство по обслуживанию

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Chapter 2
2-2
(In Exchange2000, realm name = domain name)
PLAIN
Assumes that user name and password are sent as plain text (BASE64 encoded) and the communication
packet is encoded. (RFC2595) Allows secure authentication when used in combination with the encoded
transmission described later.
LOGIN
Sends the user name and password as plain text (BASE64 encoded). Actual transaction is the same as with
PLAIN. Similarly, allows secure authentication when used in combination with encoded transmission.
<SMTP AUTH transmission operation>
Even if the unit is programmed for transmission with SMTP AUTH, if the mail server does not support
SMTP AUTH and the encoding system supported by the server does not match that supported by this mod-
el, SMTP AUTH transmission will not be possible. In that case, even if SMTP AUTH is programmed,
transmission will be by normal SMTP and there will be no transmission error generated. If an unauthen-
ticated mail transmission is attempted to a server that will not allow such transmission, subsequent SMTP
protocols will generate an error in the mail server. Unauthenticated mail can be transmitted to a server that
will accept such transmission. These security policies are determined by the server so, even if SMTP
AUTH is not programmed, it is impossible to tell whether transmission is possible without checking with
the customer's server administrator.
<Authentication protocol>
Examples of transmission protocol using SMTP AUTH are given below.
The EHLO response from the client tells whether SMTP AUTH is supported by the server and the authen-
tication algorithm being used at that time is described. In the event that there are multiple authentication
algorithms, multiple algorithm names are described. The client selects one of the relayed authentication
algorithms and then relays it on to the server. Server challenge data come from the server and coded data
made up from the server challenge data, user name and password are returned in response for authentica-
tion. In general, the authentication algorithm to be used can be selected on the server side and PLAIN and
LOGIN authentication and others which are undesirable from the perspective of security can be blocked
by the server setting. (Security policy is determined by the server.)
Server:220 smtp.example.com ESMTP server ready
Client(iR):EHLO ifax.example.com
S: 250-smtp.example.com
S: 250-DSN
S: 250-EXPN
S: 250 AUTH CRAM-MD5 DIGEST-MD5 : <- server declares authentication algorithm
C: AUTH CRAM-MD5 : <- client selects CRAM-MD5
S: 334 : <- server response (subsequently, authentication begins with CRAM-MD5.)
S: PENCeUxFREJoU0NnbmhNWitOMjNGNndAZWx3b29kLmlubm9zb2Z0LmNvbT4=
C: ZnJlZCA5ZTk1YWVlMDljNDBhZjJiODRhMGMyYjNiYmFlNzg2ZQ==
S: 235 Authentication successful.
<Authorisation algorithm selection>
Where the SMTP has multiple authentication mechanisms, selection is made in the order of the priority
list given below.
1) CRAM-MD5
2) NTLM
3) GSSAPI
4) STARTTLS operation PLAIN
5) STARTTLS operation LOGIN
6) STARTTLS non-operation LOGIN
7) STARTTLS non-operation PLAIN
Authentication methods can be disabled in service mode. When the service mode value is set to '1', the
encoding system can be disabled. (The default setting is all enabled.)
Ordinarily, the default setting is used, but if the server administrator wants to disable a particular encoding
system, the settings need to be changed by the service mode settings.