path: root/doc/rfc/rfc4777.txt

Network Working Group                                     T. Murphy, Jr.
Request for Comments: 4777                                      P. Rieth
Obsoletes: 2877                                               J. Stevens
Category: Informational                                              IBM
                                                           November 2006


                   IBM's iSeries Telnet Enhancements

Status of This Memo

   This memo provides information for the Internet community.  It does
   not specify an Internet standard of any kind.  Distribution of this
   memo is unlimited.

Copyright Notice

   Copyright (C) The IETF Trust (2006).

IESG Note

   This RFC is not a candidate for any level of Internet Standard.  The
   IETF disclaims any knowledge of the fitness of this RFC for any
   purpose and in particular notes that the decision to publish is not
   based on IETF review for such things as security, congestion control,
   or inappropriate interaction with deployed protocols.  The RFC Editor
   has chosen to publish this document at its discretion.  Readers of
   this document should exercise caution in evaluating its value for
   implementation and deployment.  See RFC 3932 for more information.

Abstract

   This document describes the interface to the Telnet server on IBM's
   iSeries line of midrange business computers.  This interface allows
   Telnet clients to request a Telnet terminal or printer session using
   specific session attributes related to device names, encryption,
   language support, auto-sign-on, response codes, session association,
   etc.

   These support functions are implemented primarily using the Telnet
   Environment option negotiation RFC 1572 to define new USERVAR
   variables that will be recognized by iSeries Telnet server.









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Table of Contents

   1. Introduction ....................................................2
   2. Standard Telnet Option Negotiation ..............................3
   3. Enhanced Telnet Option Negotiation ..............................4
   4. Enhanced Display Emulation Support ..............................7
   5. Enhanced Display Auto-Sign-On and Password Encryption ...........9
      5.1. Data Encryption Standard (DES) Password Substitutes .......13
      5.2. Secure Hash Algorithm (SHA) Password Substitutes ..........16
   6. Kerberos Services Ticket Automatic Sign-On Support .............18
   7. Device Name Collision Processing ...............................21
   8. Enhanced Printer Emulation Support .............................22
   9. Telnet Printer Terminal Types ..................................23
   10. Startup Response Record for Printer and Display Devices .......25
      10.1. Example of a Success Response Record .....................26
      10.2. Example of an Error Response Record ......................27
      10.3. Example of a Response Record with Device Name Retry ......28
      10.4. Response Codes ...........................................31
   11. Printer Steady-State Pass-Through Interface ...................33
      11.1. Example of a Print Record ................................35
      11.2. Example of a Print Complete Record .......................37
      11.3. Example of a Null Print Record ...........................37
   12. End-to-End Print Example ......................................39
   13. Security Considerations .......................................44
   14. IANA Considerations ...........................................44
   15. Normative References ..........................................44
   16. Informative References ........................................44
   17. Relation to Other RFCs ........................................45

1.  Introduction

   The iSeries Telnet server enables clients to negotiate both terminal
   and printer device names through Telnet Environment Options
   Negotiations [RFC1572].

   This allows Telnet servers and clients to exchange environment
   information using a set of standard or custom variables.  By using a
   combination of both standard VARs and custom USERVARs, the iSeries
   Telnet server allows client Telnet to request a pre-defined specific
   device by name.

   If no pre-defined device exists, then the device will be created,
   with client Telnet having the option to negotiate device attributes,
   such as the code page, character set, keyboard type, etc.

   Since printers can now be negotiated as a device name, new terminal
   types have been defined to request printers.  For example, you can




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   now negotiate "IBM-3812-1" and "IBM-5553-B01" as valid TERMINAL-TYPE
   options [RFC1091].

   Finally, the iSeries Telnet server will allow exchange of user
   profile and password information, where the password may be in either
   plain text or encrypted form.  If a valid combination of profile and
   password is received, then the client is allowed to bypass the sign-
   on panel.  The local server setting of the QRMTSIGN system value must
   be either *VERIFY or *SAMEPRF for the bypass of the sign-on panel to
   succeed.

2.  Standard Telnet Option Negotiation

   Telnet server option negotiation [RFC855] typically begins with the
   issuance, by the server, of an invitation to engage in terminal type
   negotiation with the Telnet client (DO TERMINAL-TYPE) [RFC1091].  The
   client and server then enter into a series of sub-negotiations to
   determine the level of terminal support that will be used.  After the
   terminal type is agreed upon, the client and server will normally
   negotiate a required set of additional options (EOR [RFC885], BINARY
   [RFC856], SGA [RFC858]) that are required to support "transparent
   mode" or full screen 5250/3270 block mode support.  As soon as the
   required options have been negotiated, the server will suspend
   further negotiations and begin with initializing the actual virtual
   device on the iSeries.  A typical exchange might start as follows:

   iSeries Telnet server             Enhanced Telnet client
   --------------------------        -------------------------
   IAC DO TERMINAL-TYPE        -->
                               <--   IAC WILL TERMINAL-TYPE
   IAC SB TERMINAL-TYPE SEND
   IAC SE                      -->
                                     IAC SB TERMINAL-TYPE IS
                               <--   IBM-5555-C01 IAC SE
   IAC DO EOR                  -->
                               <--   IAC WILL EOR
                               <--   IAC DO EOR
   IAC WILL EOR                -->
                                .
                                .
   (other negotiations)         .










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   Actual bytes transmitted in the above example are shown in hex below.

   iSeries Telnet server             Enhanced Telnet client
   --------------------------        -------------------------
   FF FD 18                    -->
                               <--   FF FB 18
   FF FA 18 01 FF F0           -->
                                     FF FA 18 00 49 42 4D 2D
                                     35 35 35 35 2D 43 30 31
                               <--   FF F0
   FF FD 19                    -->
                               <--   FF FB 19
                               <--   FF FD 19
   FF FB 19                    -->
                                .
                                .
   (other negotiations)         .

   Some negotiations are symmetrical between client and server, and some
   are negotiated in one direction only.  Also, it is permissible and
   common practice to bundle more than one response or request, or to
   combine a request with a response, so in practice the actual exchange
   may look different from what is shown above.

3.  Enhanced Telnet Option Negotiation

   In order to accommodate the new environment option negotiations, the
   server will bundle an environment option invitation along with the
   standard terminal type invitation request to the client.

   A client should either send a negative acknowledgment (WONT NEW-
   ENVIRON), or at some point after completing terminal-type
   negotiations, but before completing the full set of negotiations
   required for 5250 transparent mode, engage in environment option
   sub-negotiation with the server.  A maximum of 1024 bytes of
   environment strings may be sent to the server.  A recommended
   sequence might look like the following:














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   iSeries Telnet server             Enhanced Telnet client
   --------------------------        -------------------------
   IAC DO NEW-ENVIRON
   IAC DO TERMINAL-TYPE        -->
   (2 requests bundled)
                               <--   IAC WILL NEW-ENVIRON
   IAC SB NEW-ENVIRON SEND
   VAR IAC SE                  -->
                                     IAC SB NEW-ENVIRON IS
                                     VAR "USER" VALUE "JONES"
                                     USERVAR "DEVNAME"
                                     VALUE "MYDEVICE07"
                               <--   IAC SE
                               <--   IAC WILL TERMINAL-TYPE
                                     (do the terminal type
                                     sequence first)
   IAC SB TERMINAL-TYPE SEND
   IAC SE                      -->
                                     IAC SB TERMINAL-TYPE IS
                               <--   IBM-5555-C01 IAC SE
                                     (terminal type negotiations
                                     completed)
   IAC DO EOR                  -->
   (server will continue
   with normal transparent
   mode negotiations)
                               <--   IAC WILL EOR
                                .
                                .
   (other negotiations)         .





















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   Actual bytes transmitted in the above example are shown in hex below.

   iSeries Telnet server             Enhanced Telnet client
   --------------------------        -------------------------
   FF FD 27
   FF FD 18                    -->
   (2 requests bundled)
                               <--   FF FB 27
   FF FA 27 01 00 FF F0        -->
                                     FF FA 27 00 00 55 53 45
                                     52 01 4A 4F 4E 45 53 03
                                     44 45 56 4E 41 4D 45 01
                                     4D 59 44 45 56 49 43 45
                               <--   30 37 FF F0
                               <--   FF FB 18
                                     (do the terminal type
                                     sequence first)
   FF FA 18 01 FF F0           -->
                                     FF FA 18 00 49 42 4D 2D
                                     35 35 35 35 2D 43 30 31
                               <--   FF F0
   FF FD 19                    -->
   (server will continue
   with normal transparent
   mode negotiations)
                               <--   FF FB 19
                                .
                                .
   (other negotiations)         .

   Telnet environment options defines 6 standard VARs: USER, JOB, ACCT,
   PRINTER, SYSTEMTYPE, and DISPLAY.  The USER standard VAR will hold
   the value of the iSeries user profile name to be used in auto-sign-on
   requests.  The Telnet server will make no direct use of the
   additional 5 VARs, nor are any of them required to be sent.  All
   standard VARs and their values that are received by the Telnet server
   will be placed in a buffer, along with any USERVARs received
   (described below), and made available to a registered initialization
   exit program to be used for any purpose desired.

   There are some reasons you may want to send NEW-ENVIRON negotiations
   prior to TERMINAL-TYPE negotiations.  With an iSeries Telnet server,
   several virtual device modes can be negotiated: 1) VTxxx device, 2)
   3270 device, and 3) 5250 device (includes Network Station).  The
   virtual device mode selected depends on the TERMINAL-TYPE negotiated
   plus any other Telnet option negotiations necessary to support those
   modes.  The iSeries Telnet server will create the desired virtual
   device at the first opportunity it thinks it has all the requested



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   attributes needed to create the device.  This can be as early as
   completion of the TERMINAL-TYPE negotiations.

   For the case of Transparent mode (5250 device), the moment TERMINAL-
   TYPE, BINARY, and EOR options are negotiated, the Telnet server will
   go create the virtual device.  Receiving any NEW-ENVIRON negotiations
   after these option negotiations are complete will result in the NEW-
   ENVIRON negotiations having no effect on device attributes, as the
   virtual device will have already been created.

   So, for Transparent mode, NEW-ENVIRON negotiations are effectively
   closed once EOR is negotiated, since EOR is generally the last option
   done.

   For other devices modes (such as VTxxx or 3270), you cannot be sure
   when the iSeries Telnet server thinks it has all the attributes to
   create the device.  Recall that NEW-ENVIRON negotiations are
   optional, and therefore the iSeries Telnet server need not wait for
   any NEW-ENVIRON options prior to creating the virtual device.  It is
   in the clients' best interest to send NEW-ENVIRON negotiations as
   soon as possible, preferably before TERMINAL-TYPE is negotiated.
   That way, the client can be sure that the requested attributes were
   received before the virtual device is created.

4.  Enhanced Display Emulation Support

   Telnet environment option USERVARs have been defined to allow a
   compliant Telnet client more control over the Telnet server virtual
   device on the iSeries and to provide information to the Telnet server
   about the client.  These USERVARs allow the client Telnet to create
   or select a previously created virtual device.  If the virtual device
   does not exist and must be created, then the USERVAR variables are
   used to create and initialize the device attributes.  If the virtual
   device already exists, the device attributes are modified.

















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   The USERVARs defined to accomplish this are:

   USERVAR        VALUE              EXAMPLE         DESCRIPTION
   --------       ----------------   --------------  -------------------
   DEVNAME        us-ascii char(x)   MYDEVICE07      Display device name
   KBDTYPE        us-ascii char(3)   USB             Keyboard type
   CODEPAGE       us-ascii char(y)   437             Code page
   CHARSET        us-ascii char(y)   1212            Character set
   IBMSENDCONFREC us-ascii char(3)   YES | NO        Startup Response
                                                       Record desired
   IBMASSOCPRT    us_ascii char(x)   RFCPRT          Printer associated
                                                       with display
                                                       device

   x - up to a maximum of 10 characters
   y - up to a maximum of 5 characters

   For a description of the KBDTYPE, CODEPAGE, and CHARSET parameters
   and their permissible values, refer to Chapter 8 in the
   Communications Configuration Reference [COMM-CONFIG] and also to
   Appendix C in National Language Support [NLS-SUPPORT].

   The CODEPAGE and CHARSET USERVARs must be associated with a KBDTYPE
   USERVAR.  If either CODEPAGE or CHARSET are sent without KBDTYPE,
   they will default to system values.  A default value for KBDTYPE can
   be sent to force CODEPAGE and CHARSET values to be used.

   iSeries system objects such as device names, user profiles, plain
   text passwords, programs, libraries, etc., are required to be
   specified in English uppercase.  This includes:

      any letter (A-Z), any number (0-9), special characters (# $ _ @)

   Therefore, where us-ascii is specified for VAR or USERVAR values, it
   is recommended that uppercase ASCII values be sent, which will be
   converted to Extended Binary Coded Decimal Interchange Code (EBCDIC)
   by the Telnet server.

   A special case occurs for encrypted passwords (described in the next
   section), where both the initial password and user profile used to
   build the encrypted password must be EBCDIC English uppercase, in
   order to be properly authenticated by the Telnet server.

   The IBMASSOCPRT USERVAR is used to provide the device name of a
   printer that will be associated with the display device that is
   created.  The device description of the printer name provided must
   currently exist on the Telnet server system.  The IBMSENDCONFREC
   USERVAR is used by the enhanced Telnet client to inform the Telnet



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   server that a display Startup Response Record should be sent to the
   client.  This record communicates the name of the actual display
   device acquired.  If the attempt is unsuccessful, the reason code
   will be set to provide additional information on why the attempt
   failed.  In addition to the device name and reason code, the Startup
   Response Record will contain the name of the Telnet server system.

   For more details on the Startup Response Record, see Section 11 of
   this document.

5.  Enhanced Display Auto-Sign-On and Password Encryption

   To allow password encryption, new IBMRSEED and IBMSUBSPW USERVARs
   will be used to exchange seed and substitute passwords information.
   IBMRSEED will carry a random seed to be used in both the Data
   Encryption Standard (DES) and Secure Hash Algorithm (SHA) password
   encryption, and IBMSUBSPW will carry the encrypted copy of the
   password.

   The DES encryption would use the same 7-step DES-based password
   substitution scheme as APPC and Client Access.  For a description of

   DES encryption, refer to Federal Information Processing Standards
   Publications (FIPS) 46-2 [FIPS-46-2] and 81 [FIPS-81].

   The SHA encryption is described in Federal Information Processing
   Standards Publication 180-1 [FIPS-180-1].

   The FIPS documents can be found at the Federal Information Processing
   Standards Publications link:

      http://www.itl.nist.gov/fipspubs/by-num.htm

   If encrypted password exchange is not required, plain text password
   exchange is permitted using the same USERVARs defined for encryption.
   For this case, the random client seed should be set either to an
   empty value (preferred method) or to hexadecimal zeros to indicate
   the password is not encrypted, but is plain text.

   It should be noted that security of plain text password exchange
   cannot be guaranteed unless the network is physically protected or a
   trusted network (such as an intranet).  If your network is vulnerable
   to IP address spoofing or directly connected to the Internet, you
   should engage in encrypted password exchange to validate a client's
   identity.

   Additional VARs and USERVARs have also been defined to allow an
   auto-sign-on user greater control over their startup environment,



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   similar to what is supported using the Open Virtual Terminal
   (QTVOPNVT) API [SYSTEM-API].

   The standard VARs supported to accomplish this are:

   VAR        VALUE              EXAMPLE           DESCRIPTION
   --------   ----------------   ----------------  -------------------
   USER       us-ascii char(x)   USERXYZ           User profile name

   x - up to a maximum of 10 characters

   The custom USERVARs defined to accomplish this are:

   USERVAR       VALUE              EXAMPLE            DESCRIPTION
   --------      ----------------   ----------------   -----------------
   IBMRSEED      binary(8)          8-byte hex field   Random client
                                                         seed
   IBMSUBSPW     binary(128)        128-byte hex field Substitute
                                                         password
   IBMCURLIB     us-ascii char(x)   QGPL               Current library
   IBMIMENU      us-ascii char(x)   MAIN               Initial menu
   IBMPROGRAM    us-ascii char(x)   QCMD               Program to call

   x - up to a maximum of 10 characters

   In order to communicate the server random seed value to the client,
   the server will request a USERVAR name made up of a fixed part (the 8
   characters "IBMRSEED") immediately followed by an 8-byte hexadecimal
   variable part, which is the server random seed.  The client generates
   its own 8-byte random seed value and uses both seeds to encrypt the
   password.  Both the encrypted password and the client random seed
   value are then sent to the server for authentication.  Telnet
   environment option rules will need to be adhered to when transmitting
   the client random seed and substituted password values to the server.
   Specifically, since a typical environment string is a variable length
   hexadecimal field, the hexadecimal fields are required to be escaped
   and/or byte stuffed according to the RFC 854 [RFC854], where any
   single byte could be misconstrued as a Telnet IAC or other Telnet
   option negotiation control character.  The client must escape and/or
   byte stuff any bytes that could be seen as a Telnet environment
   option, specifically VAR, VALUE, ESC, and USERVAR.

   If you use the IBMSENDCONFREC USERVAR, as described in Section 5 of
   this document, with a value of YES along with the automatic sign-on
   USERVARs described above, you will receive a Startup Response Record
   that will contain a response code informing your Telnet client of the
   success or failure of the automatic sign-on attempt.  See Section 11
   of this document for details on the Startup Response Record.



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   The following illustrates the encrypted case:

   iSeries Telnet server            Enhanced Telnet client
   --------------------------       -------------------------------
   IAC DO NEW-ENVIRON          -->
                               <--  IAC WILL NEW-ENVIRON
   IAC SB NEW-ENVIRON SEND
   USERVAR "IBMRSEEDxxxxxxxx"
   USERVAR "IBMSUBSPW"
   VAR USERVAR IAC SE          -->
                                    IAC SB NEW-ENVIRON IS
                                    VAR "USER" VALUE "DUMMYUSR"
                                    USERVAR "IBMRSEED" VALUE "yyyyyyyy"
                                    USERVAR "IBMSUBSPW" VALUE "zzzzzzzz"
                               <--  IAC SE
                                .
                                .
   (other negotiations)         .

   In this example, "xxxxxxxx" is an 8-byte hexadecimal random server
   seed, "yyyyyyyy" is an 8-byte hexadecimal random client seed, and
   "zzzzzzzz" is an 8-byte hexadecimal encrypted password (if the DES
   encryption algorithm was used) or a 20-byte hexadecimal encrypted
   password (if the SHA encryption algorithm was used).  If the password
   is not valid, then the sign-on panel is not bypassed.  If the
   password is expired, then the sign-on panel is not bypassed.

   Actual bytes transmitted in the above example are shown in hex below,
   where the server seed is "7D3E488F18080404", the client seed is
   "4E4142334E414233", and the DES encrypted password is
   "DFB0402F22ABA3BA".  The user profile used to generate the encrypted
   password is "44554D4D59555352" (DUMMYUSR), with a plain text password
   of "44554D4D595057" (DUMMYPW).


















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   iSeries Telnet server            Enhanced Telnet client
   --------------------------       -------------------------
   FF FD 27                    -->
                               <--  FF FB 27
   FF FA 27 01 03 49 42 4D
   52 53 45 45 44 7D 3E 48
   8F 18 08 04 04 03 49 42
   4D 53 55 42 53 50 57 03
   00 FF F0                    -->
                                    FF FA 27 00 00 55 53 45
                                    52 01 44 55 4D 4D 59 55
                                    53 52 03 49 42 4D 52 53
                                    45 45 44 01 4E 41 42 33
                                    4E 41 42 33 03 49 42 4D
                                    53 55 42 53 50 57 01 DF
                                    B0 40 2F 22 AB A3 BA FF
                               <--  F0

   The following illustrates the plain text case:

   iSeries Telnet server            Enhanced Telnet client
   --------------------------       -------------------------
   IAC DO NEW-ENVIRON          -->
                               <--  IAC WILL NEW-ENVIRON
   IAC SB NEW-ENVIRON SEND
   USERVAR "IBMRSEEDxxxxxxxx"
   USERVAR "IBMSUBSPW"
   VAR USERVAR IAC SE          -->
                                    IAC SB NEW-ENVIRON IS
                                    VAR "USER" VALUE "DUMMYUSR"
                                    USERVAR "IBMRSEED" VALUE
                                    USERVAR "IBMSUBSPW" VALUE "yyyyyyyy"
                               <--  IAC SE
                                .
                                .
   (other negotiations)         .

   In this example, "xxxxxxxx" is an 8-byte hexadecimal random server
   seed, and "yyyyyyyyyy" is a 128-byte us-ascii client plain text
   password.  If the password has expired, then the sign-on panel is not
   bypassed.

   Actual bytes transmitted in the above example are shown in hex below,
   where the server seed is "7D3E488F18080404", the client seed is
   empty, and the plain text password is "44554D4D595057" (DUMMYPW).
   The user profile used is "44554D4D59555352" (DUMMYUSR).





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   iSeries Telnet server            Enhanced Telnet client
   --------------------------       -------------------------
   FF FD 27                    -->
                               <--  FF FB 27
   FF FA 27 01 03 49 42 4D
   52 53 45 45 44 7D 3E 48
   8F 18 08 04 04 03 49 42
   4D 53 55 42 53 50 57 03
   00 FF F0                    -->
                                    FF FA 27 00 00 55 53 45
                                    52 01 44 55 4D 4D 59 55
                                    53 52 03 49 42 4D 52 53
                                    45 45 44 01 03 49 42 4D
                                    53 55 42 53 50 57 01 44
                               <--  55 4D 4D 59 50 57 FF F0

5.1.  Data Encryption Standard (DES) Password Substitutes

   Both APPC and Client Access use well-known DES encryption algorithms
   to create encrypted passwords.  A Network Station or Enhanced Client
   can generate compatible encrypted passwords if it follows these
   steps, details of which can be found in the Federal Information
   Processing Standards 46-2 [FIPS-46-2].

   1) Padded_PW = Left justified user password padded to the right with
      '40'X to 8 bytes.

      The user's password must be left justified in an 8-byte variable
      and padded to the right with '40'X up to an 8-byte length.  If the
      user's password is 8 bytes in length, no padding will occur.  For
      computing password substitutes for passwords of length 9 and 10,
      see "Handling passwords of length 9 and 10" below.  Passwords less
      than 1 byte or greater than 10 bytes in length are not valid.
      Please note that if password is not in EBCDIC, it must be
      converted to EBCDIC uppercase.

   2) XOR_PW = Padded_PW xor '5555555555555555'X

      The padded password is Exclusive OR'ed with 8 bytes of '55'X.

   3) SHIFT_RESULT = XOR_PW << 1

      The entire 8-byte result is shifted 1 bit to the left; the left-
      most bit value is discarded, and the rightmost bit value is
      cleared to 0.

   4) PW_TOKEN = DES_ECB_mode(SHIFT_RESULT,              /* key  */
                              userID_in_EBCDIC_uppercase /* data */ )



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      This shifted result is used as key to the Data Encryption Standard
      (Federal Information Processing Standards 46-2 [FIPS-46-2]) to
      encipher the user identifier.  When the user identifier is less
      than 8 bytes, it is left justified in an 8-byte variable and
      padded to the right with '40'X.  When the user identifier is 9 or
      10 bytes, it is first padded to the right with '40'X to a length
      of 10 bytes.  Then bytes 9 and 10 are "folded" into bytes 1-8
      using the following algorithm:

        Bit 0 is the high-order bit (i.e., has value of '80'X).

        Byte 1, bits 0 and 1 are replaced with byte 1, bits 0 and 1
        Exclusive OR'ed with byte 9, bits 0 and 1.
        Byte 2, bits 0 and 1 are replaced with byte 2, bits 0 and 1
        Exclusive OR'ed with byte 9, bits 2 and 3.
        Byte 3, bits 0 and 1 are replaced with byte 3, bits 0 and 1
        Exclusive OR'ed with byte 9, bits 4 and 5.
        Byte 4, bits 0 and 1 are replaced with byte 4, bits 0 and 1
        Exclusive OR'ed with byte 9, bits 6 and 7.
        Byte 5, bits 0 and 1 are replaced with byte 5, bits 0 and 1
        Exclusive OR'ed with byte 10, bits 0 and 1.
        Byte 6, bits 0 and 1 are replaced with byte 6, bits 0 and 1
        Exclusive OR'ed with byte 10, bits 2 and 3.
        Byte 7, bits 0 and 1 are replaced with byte 7, bits 0 and 1
        Exclusive OR'ed with byte 10, bits 4 and 5.
        Byte 8, bits 0 and 1 are replaced with byte 8, bits 0 and 1
        Exclusive OR'ed with byte 10, bits 6 and 7.

      User identifiers greater than 10 bytes or less than 1 byte are not
      the result of this encryption ID, known as PW_TOKEN in the paper.

   5) Increment PWSEQs and store it.

      Each LU must maintain a pair of sequence numbers for ATTACHs sent
      and received on each session.  Each time an ATTACH is generated,
      (and password substitutes are in use on the session) the sending
      sequence number, PWSEQs, is incremented and saved for the next
      time.  Both values are set to zero at BIND time.  So the first use
      of PWSEQs has the value of 1 and increases by one with each use.
      A new field is added to the ATTACH to carry this sequence number.
      However, in certain error conditions, it is possible for the
      sending side to increment the sequence number, and the receiver
      may not increment it.  When the sender sends a subsequent ATTACH,
      the receiver will detect a missing sequence.  This is allowed.
      However the sequence number received must always be larger than
      the previous one, even if some are missing.





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      The maximum number of consecutive missing sequence numbers allowed
      is 16.  If this is exceeded, the session is unbound with a
      protocol violation.

      Note: The sequence number must be incremented for every ATTACH
      sent.  However, the sequence number field is only required to be
      included in the FMH5 if a password substitute is sent (byte 4, bit
      3 on).

   6) RDrSEQ = RDr + PWSEQs  /* RDr is server seed. */

      The current value of PWSEQs is added to RDr, the random value
      received from the partner LU on this session, yielding RDrSEQ,
      essentially a predictably modified value of the random value
      received from the partner LU at BIND time.

   7) PW_SUB = DES_CBC_mode(PW_TOKEN,        /* key      */
                            (RDrSEQ,         /* 8 bytes  */
                             RDs,            /* 8 bytes  */
                             ID xor RDrSEQ,  /* 16 bytes */
                             PWSEQs,         /* 8 bytes  */
                             )               /* data     */
                            )

        The PW_TOKEN is used as a key to the DES function to generate an
        8-byte value for the following string of inputs.  The DES CBC
        mode Initialization Vector (IV) used is 8 bytes of '00'X.

          RDrSEQ: the random data value received from the partner LU
                  plus the sequence number.

          RDs:    the random data value sent to the partner LU on BIND
                  for this session.

          A 16-byte value created by:

                  - padding the user identifier with '40'X to a length
                    of 16 bytes.

                  - Exclusive OR'ing the two 8-byte halves of the padded
                    user identifier with the RDrSEQ value.

                    Note: User ID must first be converted to EBCDIC
                    uppercase.

          PWSEQs: the sequence number.





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      This is similar to the process used on LU-LU verification as
      described in the Enhanced LU-LU Bind Security.  The resulting
      enciphered random data is the 'password substitute'.

   8) Handling passwords of length 9 and 10

      1. Generate PW_TOKENa by using characters 1 to 8 of the password
         and steps 1-4 from the previous section.

      2. Generate PW_TOKENb by using characters 9 and 10 and steps 1-4
         from the previous section.  In this case, Padded_PW from step 1
         will be characters 9 and 10 padded to the right with '40'X, for
         a total length of 8.

      3. PW_TOKEN = PW_TOKENa xor PW_TOKENb

      4. Now compute PW_SUB by performing steps 5-7 from the previous
         section.

   9) Example DES Password Substitute Calculation

      ID:           USER123
      Password:     ABCDEFG
      Server seed:  '7D4C2319F28004B2'X
      Client seed:  '08BEF662D851F4B1'X
      PWSEQs:       1     (PWSEQs is a sequence number needed in the
                           7-step encryption, and it is always one)

      DES Encrypted Password should be: '5A58BD50E4DD9B5F'X

5.2.  Secure Hash Algorithm (SHA) Password Substitutes

   A Network Station or Enhanced Client can generate SHA encrypted
   passwords if it follows these steps.

   1) Convert the user identifier to uppercase UNICODE format (if it is
      not already in this format).

      The user identifier must be left justified in a 10-byte variable
      and padded to the right with '40'X up to a 10-byte length prior to
      converting it to UNICODE.  If the user's password is 10 bytes in
      length, no padding will occur.  User identifiers of less than 1
      byte or greater than 10 bytes in length are not valid.  The user
      identifier will be 20 bytes in length after conversion to UNICODE,
      so the variable that will hold the UNICODE user identifier should
      have a length of 20 bytes.





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   2) Ensure the password is in UNICODE format (if it is not already in
      this format).

      The user's password must be left justified in a 128-byte variable.
      It does not need to be padded to the right with '40'X up to a
      128-byte length.  Passwords less than 1 byte or greater than 128
      bytes in length are not valid. The password will be 2 times its
      original length after conversion to UNICODE, so the maximum length
      of the variable that will hold the UNICODE password is 256 bytes.

   3) Create a 20-byte password token as follows:

      PW_token = SHA-1(uppercase_unicode_userid,         /* 20 bytes */
                       unicode_password)      /* from 2 to 256 bytes */

      The actual routine to be used to perform the SHA-1 processing is
      dependent on the programming language being used.  For example, if
      using the Java language, then use the java.security class to
      perform the actual SHA-1 processing.

      The PW_token will be used in subsequent step to actually generate
      the final substitute password.

   4) Increment PWSEQs and store it.

   5) Create the 20-byte substitute password as follows:

      PW_SUB = SHA-1(PW_token,                        /* 20 bytes */
                     serverseed,                      /*  8 bytes */
                     clientseed,                      /*  8 bytes */
                     uppercase_unicode_userid,        /* 20 bytes */
                     PWSEQ)                           /*  8 bytes */

      The actual routine to be used to perform the SHA-1 processing is
      dependent on the programming language being used.  For example, if
      using the Java language, then use the java.security class to
      perform the actual SHA-1 processing.

   6) Example SHA Password Substitute Calculation

      ID:           USER123
      Password:     AbCdEfGh123?+
      Server seed:  '3E3A71C78795E5F5'X
      Client seed:  'B1C806D5D377D994'X
      PWSEQs:       1     (PWSEQs is a sequence number needed in the
                           SHA encryption, and it is always one)





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      SHA Encrypted Password should be:

               'E7FAB5F034BEDA42E91F439DD07532A24140E3DD'X

6.  Kerberos Services Ticket Automatic Sign-On Support

   An iSeries Telnet server specific USERVAR defined below will contain
   the complete Generic Security Services (GSS) token for use on the
   iSeries.  Enhanced Telnet clients will need to obtain the Kerberos
   services ticket from a Key Distribution Center (KDC).  Implementation
   steps for acquiring the Kerberos services ticket will be limited to
   the Microsoft Security Support Provider Interface (SSPI) example
   below.  For information on Kerberos services tickets, refer to your
   Network Authentication Service (NAS) documentation.

   The custom USERVAR defined is:

   USERVAR   VALUE         EXAMPLE              DESCRIPTION
   --------- ------------- -------------------- -------------------
   IBMTICKET binary(16384) 16384-byte hex field Kerberos services token

   Several other USERVARs, as defined in Section 6, can be used along
   with the IBMTICKET USERVAR to allow a user greater control over their
   startup environment.

   The custom USERVARs defined to accomplish this are:

   USERVAR       VALUE              EXAMPLE            DESCRIPTION
   --------      ----------------   ----------------   -----------------
   IBMCURLIB     us-ascii char(x)   QGPL               Current library
   IBMIMENU      us-ascii char(x)   MAIN               Initial menu
   IBMPROGRAM    us-ascii char(x)   QCMD               Program to call

   x - up to a maximum of 10 characters

   If you use the IBMSENDCONFREC USERVAR, as described in Section 5,
   with a value of YES along with the Kerberos ticket USERVARs described
   above, you will receive a Startup Response Record that will contain a
   response code informing your Telnet client of the success or failure
   of the Kerberos validation attempt.  See Section 11 for details on
   the Startup Response Record.

   The following Microsoft SSPI example illustrates how to get the
   client security token, which contains the Kerberos services ticket.







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   1) Get a handle to the user's credentials:

      PSecurityFunctionTable pSSPI_;
      CredHandle credHandle;
      TimeStamp  timeStamp;

      ss = pSSPI_->AcquireCredentialsHandle(
                   NULL,                 // Principal
                   "Kerberos",           // PackageName
                   SECPKG_CRED_OUTBOUND, // CredentialUse
                   NULL,                 // LogonID
                   NULL,                 // AuthData
                   NULL,                 // GetKeyFnc
                   NULL,                 // GetKeyArg
                   &credHandle,          // CredHandle
                   &timeStamp);          // ExpireTime

   2) Initialize security context to "request delegation".  Mutual
      authentication is also requested, although it is not required and
      may not be performed.

      CtxtHandle newContext;
      unsigned long contextAttr;
      unsigned char token[16384] ;
      unsigned long tokenLen = sizeof(token);
      SecBuffer sbo = {tokenLen, SECBUFFER_TOKEN, token};
      SecBufferDesc sbdo = {SECBUFFER_VERSION, 1, &sbo}

      pSSPI_->InitializeSecurityContext(
              &credHandle,               // CredHandle
              NULL,                      // Context
              "krbsrv400/fullyqualifiedLowerCaseSystemName",
                                         // ServicePrincipalName
              ISC_REQ_CONNECTION|ISC_REQ_DELEGATE|ISC_REQ_MUTUAL_AUTH,
                                         // ContextRequest
              NULL,                      // Reserved
              SECURITY_NATIVE_DREP,      // DataRep
              NULL,                      // Input
              NULL,                      // Reserved
              &newContext,               // NewContext
              &sbdo,                     // Output
              &contextAttr,              // ContextAttr
              &timeStamp);               // ExpireTime

   3) Free the user credentials handle with FreeCredentialsHandle().

   4) Send security token to Telnet Server (padded with escape
      characters).



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   The following illustrates the Kerberos Token Negotiation:

   iSeries Telnet server            Enhanced Telnet client
   --------------------------       -------------------------------
   IAC DO NEW-ENVIRON          -->
                               <--  IAC WILL NEW-ENVIRON
   IAC SB NEW-ENVIRON SEND
   USERVAR "IBMRSEEDxxxxxxxx"
   VAR USERVAR IAC SE          -->
                                    IAC SB NEW-ENVIRON IS
                                    USERVAR "IBMTICKET" VALUE
                                    "zzzzzzzz..."
                               <--  IAC SE
                                .
                                .
   (other negotiations)         .

   In this example, "xxxxxxxx" is an 8-byte hexadecimal random server
   seed, and "zzzzzzzz..." is the complete Kerberos services token.  If
   the Kerberos services token is not valid, then the sign-on panel is
   not bypassed.  It should be noted that for the Kerberos token a
   random server seed is not needed, although it will be sent by the
   Telnet Server.

   Actual bytes transmitted in the above example are shown in hex below,
   where the server seed is "7D3E488F18080404", and the Kerberos
   services token starts with "DFB0402F22ABA3BA...".  The complete
   Kerberos services token is not shown here, as the length of the token
   could be 16384 bytes and would make this document extremely large.
   As described in Section 6, the client must escape and/or byte stuff
   any Kerberos token bytes, which could be seen as a Telnet environment
   option [RFC1572], specifically VAR, VALUE, ESC, and USERVAR.

   iSeries Telnet server            Enhanced Telnet client
   --------------------------       -------------------------
   FF FD 27                    -->
                               <--  FF FB 27
   FF FA 27 01 03 49 42 4D
   52 53 45 45 44 7D 3E 48
   8F 18 08 04 04 00 03 FF
   F0                          -->
                                    FF FA 27 00 03 49 42 4D
                                    54 49 43 48 45 54 01 DF
                                    B0 40 2F 22 AB A3 BA...
                               <--  FF F0






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7.  Device Name Collision Processing

   Device name collision occurs when a Telnet client sends the Telnet
   server a virtual device name that it wants to use, but that device is
   already in use on the server.  When this occurs, the Telnet server
   sends a request to the client asking it to try another device name.
   The environment option negotiation uses the USERVAR name of DEVNAME
   to communicate the virtual device name.  The following shows how the
   Telnet server will request the Telnet client to send a different
   DEVNAME when device name collision occurs.

   iSeries Telnet server            Enhanced Telnet client
   --------------------------       -------------------------
   IAC SB NEW-ENVIRON SEND
   VAR USERVAR IAC SE         -->

   Server requests all environment variables be sent.

                                    IAC SB NEW-ENVIRON IS USERVAR
                                    "DEVNAME" VALUE "MYDEVICE1"
                                    USERVAR "xxxxx" VALUE "xxx"
                                    ...
                              <--   IAC SE

   Client sends all environment variables, including DEVNAME.  Server
   tries to select device MYDEVICE1.  If the device is already in use,
   server requests DEVNAME be sent again.

   IAC SB NEW-ENVIRON SEND
   USERVAR "DEVNAME" IAC SE   -->

   Server sends a request for a single environment variable: DEVNAME

                                    IAC SB NEW-ENVIRON IS USERVAR
                              <--   "DEVNAME" VALUE "MYDEVICE2" IAC SE

   Client sends one environment variable, calculating a new value of
   MYDEVICE2.  If MYDEVICE2 is different from the last request, then
   server tries to select device MYDEVICE2, else server disconnects
   client.  If MYDEVICE2 is also in use, server will send DEVNAME
   request again and keep doing so until it receives a device that is
   not in use, or the same device name twice in row.









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8.  Enhanced Printer Emulation Support

   Telnet environment option USERVARs have been defined to allow a
   compliant Telnet client more control over the Telnet server virtual
   device on the iSeries.  These USERVARs allow the client Telnet to
   select a previously created virtual device or auto-create a new
   virtual device with requested attributes.

   This makes the enhancements available to any Telnet client that
   chooses to support the new negotiations.

   The USERVARs defined to accomplish this are:

   USERVAR       VALUE            EXAMPLE           DESCRIPTION
   ------------- ---------------- ----------------  -------------------
   DEVNAME       us-ascii char(x) PRINTER1          Printer device name
   IBMIGCFEAT    us-ascii char(6) 2424J0            IGC feature (DBCS)
   IBMMSGQNAME   us-ascii char(x) QSYSOPR           *MSGQ name
   IBMMSGQLIB    us-ascii char(x) QSYS              *MSGQ library
   IBMFONT       us-ascii char(x) 12                Font
   IBMFORMFEED   us-ascii char(1) C | U | A         Formfeed
   IBMTRANSFORM  us-ascii char(1) 1 | 0             Transform
   IBMMFRTYPMDL  us-ascii char(x) *IBM42023         Mfg. type and model
   IBMPPRSRC1    binary(1)        1-byte hex field  Paper source 1
   IBMPPRSRC2    binary(1)        1-byte hex field  Paper source 2
   IBMENVELOPE   binary(1)        1-byte hex field  Envelope hopper
   IBMASCII899   us-ascii char(1) 1 | 0             ASCII 899 support
   IBMWSCSTNAME  us-ascii char(x) *NONE             WSCST name
   IBMWSCSTLIB   us-ascii char(x) *LIBL             WSCST library

   x - up to a maximum of 10 characters

   The "IBM" prefix on the USERVARs denotes iSeries-specific attributes.

   The DEVNAME USERVAR is used for both displays and printers.  The
   IBMFONT and IBMASCII899 are used only for SBCS environments.

   For a description of most of these parameters (drop the "IBM" from
   the USERVAR) and their permissible values, refer to Chapter 8 in the
   Communications Configuration Reference [COMM-CONFIG].

   The IBMIGCFEAT supports the following variable DBCS language
   identifiers in position 5 (positions 1-4 must be '2424'; position 6
   must be '0'):

       'J' = Japanese              'K' = Korean
       'C' = Traditional Chinese   'S' = Simplified Chinese




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   The IBMTRANSFORM and IBMASCII899 values correspond to:

       '1' = Yes  '0' = No

   The IBMFORMFEED values correspond to:

       'C' = Continuous  'U' = Cut  'A' = Autocut

   The IBMPPRSRC1, IBMPPRSRC2, and IBMENVELOPE custom USERVARs do not
   map directly to their descriptions in Chapter 8 in the Communications
   Configuration Reference [COMM-CONFIG].  To map these, use the index
   listed here:

   IBMPPRSRC1    HEX     IBMPPRSRC2    HEX     IBMENVELOPE    HEX
   ----------   -----    ----------   -----    -----------   -----
   *NONE        'FF'X    *NONE        'FF'X    *NONE         'FF'X
   *MFRTYPMDL   '00'X    *MFRTYPMDL   '00'X    *MFRTYPMDL    '00'X
   *LETTER      '01'X    *LETTER      '01'X    *B5           '06'X
   *LEGAL       '02'X    *LEGAL       '02'X    *MONARCH      '09'X
   *EXECUTIVE   '03'X    *EXECUTIVE   '03'X    *NUMBER9      '0A'X
   *A4          '04'X    *A4          '04'X    *NUMBER10     '0B'X
   *A5          '05'X    *A5          '05'X    *C5           '0C'X
   *B5          '06'X    *B5          '06'X    *DL           '0D'X
   *CONT80      '07'X    *CONT80      '07'X
   *CONT132     '08'X    *CONT132     '08'X
   *A3          '0E'X    *A3          '0E'X
   *B4          '0F'X    *B4          '0F'X
   *LEDGER      '10'X    *LEDGER      '10'X

9.  Telnet Printer Terminal Types

   New Telnet options are defined for the printer pass-through mode of
   operation.  To enable printer pass-through mode, both the client and
   server must agree to support at least the Transmit-Binary, End-Of-
   Record, and Terminal-Type Telnet options.  The following are new
   terminal types for printers:

   TERMINAL-TYPE  DESCRIPTION
   -------------  -------------------
   IBM-5553-B01   Double-Byte printer
   IBM-3812-1     Single-Byte printer

   Specific characteristics of the IBM-5553-B01 or IBM-3812-1 printers
   are specified through the USERVAR IBMMFRTYPMDL, which specifies the
   manufacturer type and model.






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   An example of a typical negotiation process to establish printer
   pass-through mode of operation is shown below.  In this example, the
   server initiates the negotiation by sending the DO TERMINAL-TYPE
   request.

   For DBCS environments, if IBMTRANSFORM is set to 1 (use Host Print
   Transform), then the virtual device created is 3812, not 5553.
   Therefore, IBM-3812-1 (and not IBM-5553-B01) should be negotiated for
   TERMINAL-TYPE.

   iSeries Telnet server           Enhanced Telnet client
   --------------------------      --------------------------
   IAC DO NEW-ENVIRON         -->
                              <--  IAC WILL NEW-ENVIRON
   IAC SB NEW-ENVIRON SEND
   VAR USERVAR IAC SE         -->
                                   IAC SB NEW-ENVIRON IS
                                   USERVAR "DEVNAME" VALUE "PCPRINTER"
                                   USERVAR "IBMMSGQNAME" VALUE "QSYSOPR"
                                   USERVAR "IBMMSGQLIB" VALUE "*LIBL"
                                   USERVAR "IBMTRANSFORM" VALUE "0"
                                   USERVAR "IBMFONT" VALUE "12"
                                   USERVAR "IBMFORMFEED" VALUE "C"
                                   USERVAR "IBMPPRSRC1" VALUE ESC '01'X
                                   USERVAR "IBMPPRSRC2" VALUE '04'X
                                   USERVAR "IBMENVELOPE" VALUE IAC 'FF'X

                              <--  IAC SE
   IAC DO TERMINAL-TYPE       -->
                              <--  IAC WILL TERMINAL-TYPE
   IAC SB TERMINAL-TYPE SEND

   IAC SE                     -->
                                   IAC SB TERMINAL-TYPE IS IBM-3812-1
                              <--  IAC SE
   IAC DO BINARY              -->
                              <--  IAC WILL BINARY
   IAC DO EOR                 -->
                              <--  IAC WILL EOR

   Some points about the above example.  The IBMPPRSRC1 value requires
   escaping the value using ESC according to Telnet environment options
   [RFC1572].  The IBMPPRSRC2 does not require an ESC character since
   '04'X has no conflict with environment options.  Finally, to send
   'FF'X for the IBMENVELOPE value, escape the 'FF'X value by using
   another 'FF'X (called "doubling"), so as not to have the value
   interpreted as a Telnet character per the Telnet protocol
   specification [RFC854].



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   Actual bytes transmitted in the above example are shown in hex below.

   iSeries Telnet server            Enhanced Telnet client
   --------------------------       --------------------------
   FF FD 27                    -->
                               <--  FF FB 27
   FF FA 27 01 00 03 FF F0     -->
                                    FF FA 27 00 03 44 45 56
                                    4E 41 4D 45 01 50 43 50
                                    52 49 4E 54 45 52 03 49
                                    42 4D 4D 53 47 51 4E 41
                                    4D 45 01 51 53 59 53 4F
                                    50 52 03 49 42 4D 4D 53
                                    47 51 4C 49 42 01 2A 4C
                                    49 42 4C 03 49 42 4D 54
                                    52 41 4E 53 46 4F 52 4D
                                    01 30 03 49 42 4D 46 4F
                                    4E 54 01 31 32 03 49 42
                                    4D 46 4F 52 4D 46 45 45
                                    44 01 43 03 49 42 4D 50
                                    50 52 53 52 43 31 01 02
                                    01 03 49 42 4D 50 50 52
                                    53 52 43 32 01 04 03 49
                                    42 4D 45 4E 56 45 4C 4F
                               <--  50 45 01 FF FF FF F0
   FF FD 18                    -->
                               <--  FF FB 18
   FF FA 18 01 FF F0           -->
                                    FF FA 18 00 49 42 4D 2D
                               <--  33 38 31 32 2D 31 FF F0
   FF FD 00                    -->
                               <--  FF FB 00
   FF FD 19                    -->
                                    FF FB 19

10.  Startup Response Record for Printer and Display Devices

   Once Telnet negotiation for a 5250 pass-through mode is completed,
   the iSeries Telnet server will initiate a virtual device (printer or
   display) power-on sequence on behalf of the Telnet client.  The
   Telnet server will supply a Startup Response Record to the Telnet
   client with the status of the device power-on sequence, indicating
   success or failure of the virtual device power-on sequence.

   This section shows an example of two Startup Response Records.  The
   source device is a type 3812 model 01 printer with the name
   "PCPRINTER" on the target system "TARGET".




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   Figure 1 shows an example of a successful response; Figure 2 shows an
   example of an error response.

10.1.  Example of a Success Response Record

   The response record in Figure 1 was sent by an iSeries at Release
   V4R2.  It is an example of the target sending back a successful
   Startup Response Record.

   +------------------------------------------------------------------+
   |       +-----  Pass-Through header                                |
   |       |          +---  Response data                             |
   |       |          |            +----  Start diagnostic information|
   |       |          |            |                                  |
   | +----------++----------++--------------------------------------- |
   | |          ||          ||                                        |
   | 004912A090000560060020C0003D0000C9F9F0F2E3C1D9C7C5E34040D7C3D7D9 |
   |                                 |      | T A R G E T     P C P R |
   |                                 +------+                         |
   |                           Response Code (I902)                   |
   |                                                                  |
   | ---------------------------------------------------------------- |
   |                                                                  |
   | C9D5E3C5D9400000000000000000000000000000000000000000000000000000 |
   |  I N T E R                                                       |
   |                                                                  |
   |                  +------- End of diagnostic information          |
   |                  |                                               |
   | -----------------+                                               |
   |                  |                                               |
   | 000000000000000000                                               |
   +------------------------------------------------------------------+

             Figure 1.  Example of a success response record

   - '0049'X = Length pass-through data, including this length field
   - '12A0'X = GDS LU6.2 header
   - '90000560060020C0003D0000'X = Fixed value fields
   - 'C9F9F0F2'X                 = Response Code (I902)
   - 'E3C1D9C7C5E34040'X         = System Name (TARGET)
   - 'D7C3D7D9C9D5E3C5D940'X     = Object Name (PCPRINTER)










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10.2.  Example of an Error Response Record

   The response record in Figure 2 is one that reports an error.  The
   virtual device named "PCPRINTER" is not available on the target
   system "TARGET" because the device is not available.  You would
   normally see this error if the printer were already assigned to
   another Telnet session.

   +------------------------------------------------------------------+
   |       +-----  Pass-Through header                                |
   |       |          +---  Response data                             |
   |       |          |            +----  Start diagnostic information|
   |       |          |            |                                  |
   | +----------++----------++--------------------------------------- |
   | |          ||          ||                                        |
   | 004912A09000056006008200003D0000F8F9F0F2E3C1D9C7C5E34040D7C3D7D9 |
   |                                 |      | T A R G E T     P C P R |
   |                                 +------+                         |
   |                           Response Code (8902)                   |
   |                                                                  |
   | ---------------------------------------------------------------- |
   |                                                                  |
   | C9D5E3C5D9400000000000000000000000000000000000000000000000000000 |
   |  I N T E R                                                       |
   |                                                                  |
   |                  +------- End of diagnostic information          |
   |                  |                                               |
   | -----------------+                                               |
   |                  |                                               |
   | 000000000000000000                                               |
   +------------------------------------------------------------------+

             Figure 2.  Example of an error response record

   - '0049'X = Length pass-through data, including this length field
   - '12A0'X = GDS LU6.2 header
   - '90000560060020C0003D0000'X = Fixed value fields
   - 'F8F9F0F2'X                 = Response Code (8902)
   - 'E3C1D9C7C5E34040'X         = System Name (TARGET)
   - 'D7C3D7D9C9D5E3C5D940'X     = Object Name (PCPRINTER)











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10.3.  Example of a Response Record with Device Name Retry

   The Response Record can be used in conjunction with the DEVNAME
   Environment variable to allow client emulators to inform users of
   connection failures.  In addition, this combination could be used by
   client emulators that accept multiple device names to try on session
   connections.  The client would be able to walk through a list of
   possible device names and provide feedback based on the response
   code(s) received for each device name that was rejected.

   The following sequence shows a negotiation between the client and the
   server in which a named device "RFCTEST" is requested by the client.
   The device name is already assigned to an existing condition.  The
   server responds with the Response Record showing an 8902 response
   code.  The client could use this information to inform the user that
   the device name just tried was already in use.  Following the
   Response Record the server would then invite the client to try
   another device name.  Because the same device name was used again by
   the client, the server closed the session.
































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RFC 4777           IBM's iSeries Telnet Enhancements       November 2006


   iSeries Telnet server            Enhanced Telnet client
   --------------------------       -------------------------
   IAC DO NEW-ENVIRON          -->
                               <--   IAC WILL NEW-ENVIRON
   IAC DO TERMINAL-TYPE        -->
                               <--   IAC WILL TERMINAL-TYPE
   IAC SB NEW-ENVIRON SEND
   USERVAR "IBMRSEEDxxxxxxxx"
   VAR USERVAR IAC SE          -->
                                     IAC SB NEW-ENVIRON IS
                                     USERVAR "DEVNAME"
                                     VALUE "RFCTEST"
                                     USERVAR "IBMSENDCONFREC"
                                     VALUE "YES"
                               <--   IAC SE
   IAC SB TERMINAL-TYPE SEND
   IAC SE                      -->
                                     IAC SB TERMINAL-TYPE IS
                               <--   IBM-3180-2 IAC SE
                                     (terminal type negotiations
                                     completed)
   IAC DO EOR                  -->
                               <--   IAC WILL EOR
   IAC WILL EOR                -->
                               <--   IAC DO EOR
   IAC DO BINARY               -->
                               <--   IAC WILL BINARY
   IAC WILL BINARY             -->
                               <--   IAC DO BINARY
   (73 BYTE RFC 1205 RECORD
   WITH 8902 ERROR CODE)       -->
   IAC SB NEW-ENVIRON SEND
   USERVAR "DEVNAME"
   IAC SE                      -->
                                     IAC SB NEW-ENVIRON IS
                                     USERVAR "DEVNAME"
                                     VALUE "RFCTEST"
                                     USERVAR "IBMSENDCONFREC"
                                     VALUE "YES"
                               <--   IAC SE
   (server closes connection)










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   Actual bytes transmitted in the above example are shown in hex below.

   iSeries Telnet server            Enhanced Telnet client
   --------------------------       --------------------------
   FF FD 27                    -->
                               <--  FF FB 27
   FF FD 18                    -->
                               <--  FF FB 18
   FF FA 27 01 03 49 42 4D
   52 53 45 45 44 C4 96 67
   76 9A 23 E3 34 00 03 FF
   F0                          -->
                                    FF FA 27 00 03 44 45 56
                                    4E 41 4D 45 01 52 46 43
                                    54 45 53 54 03 49 42 4D
                                    53 45 4E 44 43 4F 4E 46
                                    52 45 43 01 59 45 53 FF
                               <--  F0
   FF FA 18 01 FF F0           -->
                               <--  FF FA 18 00 49 42 4D 2D
                                    33 31 38 30 2D 32 FF F0
   FF FD 19                    -->
                               <--  FF FB 19
   FF FB 19                    -->
                               <--  FF FD 19
   FF FD 00                    -->
                               <--  FF FB 00
   FF FB 00                    -->
                               <--  FF FD 00
   00 49 12 A0 90 00 05 60
   06 00 20 C0 00 3D 00 00
   F8 F9 F0 F2 D9 E2 F0 F3
   F5 40 40 40 00 00 00 00
   00 00 00 00 00 00 00 00
   00 00 00 00 00 00 00 00
   00 00 00 00 00 00 00 00
   00 00 00 00 00 00 00 00
   00 00 00 00 00 00 00 00
   00 FF EF                    -->
   FF FA 27 01 03 44 45 56
   4E 41 4D 45 FF F0           -->
                               <--  FF FA 27 00 03 44 45 56
                                    4E 41 4D 45 01 52 46 43
                                    54 45 53 54 03 49 42 4D
                                    53 45 4E 44 43 4F 4E 46
                                    52 45 43 01 59 45 53 FF
                                    F0




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RFC 4777           IBM's iSeries Telnet Enhancements       November 2006


10.4.  Response Codes

   The Start-Up Response Record success response codes:

   CODE    DESCRIPTION
   ----    ------------------------------------------------------
   I901    Virtual device has less function than source device.
   I902    Session successfully started.
   I906    Automatic sign-on requested, but not allowed.
           Session still allowed; a sign-on screen will be
           coming.

   The Start-Up Response Record error response codes:

   CODE    DESCRIPTION
   ----    ------------------------------------------------------
   2702    Device description not found.
   2703    Controller description not found.
   2777    Damaged device description.
   8901    Device not varied on.
   8902    Device not available.
   8903    Device not valid for session.
   8906    Session initiation failed.
   8907    Session failure.
   8910    Controller not valid for session.
   8916    No matching device found.
   8917    Not authorized to object.
   8918    Job canceled.
   8920    Object partially damaged.
   8921    Communications error.
   8922    Negative response received.
   8923    Start-up record built incorrectly.
   8925    Creation of device failed.
   8928    Change of device failed.
   8929    Vary on or vary off failed.
   8930    Message queue does not exist.
   8934    Start-up for S/36 WSF received.
   8935    Session rejected.
   8936    Security failure on session attempt.
   8937    Automatic sign-on rejected.
   8940    Automatic configuration failed or not allowed.
   I904    Source system at incompatible release.









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   The Start-Up Response Record error response codes for non-Kerberos
   Services Token automatic sign-on:

      CODE    DESCRIPTION
      ----    ------------------------------------------------------
      0001    System error.
      0002    Userid unknown.
      0003    Userid disabled.
      0004    Invalid password/passphrase/token.
      0005    Password/passphrase/token is expired.
      0006    Pre-V2R2 password.
      0008    Next invalid password/passphrase/token will revoke userid.

   The Start-Up Response Record error response codes for Kerberos
   Services Token automatic sign-on support:

   CODE    DESCRIPTION
   ----    ------------------------------------------------------
   0001    User profile is disabled.
   0002    Kerberos principal maps to a system user profile.
   0003    Enterprise Identity Map (EIM) configuration error.
   0004    EIM does not map Kerberos principal to user profile.
   0005    EIM maps Kerberos principal to multiple user profiles.
   0006    EIM maps Kerberos principal to user profile not found on
           system.
   1000    None of the requested mechanisms are supported by the
           local system.
   2000    The input name is not formatted properly or is not valid.
   6000    The received input token contains an incorrect signature.
   7000    No credentials available or credentials valid for context
           init only.
   9000    Consistency checks performed on the input token failed.
   A000    Consistency checks on the cred structure failed.
   B000    Credentials are no longer valid.
   D000    The runtime failed for reasons that are not defined at the
           GSS level.

   In the case where the USERVAR, DEVNAME USERVAR, IBMSENDCONFREC
   USERVAR, IBMSUBSPW USERVAR, and IBMRSEED USERVAR are all used
   together, any device errors will take precedence over automatic
   sign-on errors.  That is:

   1) If the requested named device is not available or an error occurs
      when attempting to create the device on the server system, a
      device related return code (i.e., 8902) will be sent to the client
      system in the display confirmation record.





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   2) If the requested named device is available or no errors occur when
      attempting to create the device on the server system, an automatic
      sign-on return code (i.e., 0002) will be sent to the client system
      in the display confirmation record.

11.  Printer Steady-State Pass-Through Interface

   The information in this section applies to the pass-through session
   after the receipt of startup confirmation records is complete.

   Following is the printer header interface used by Telnet.

   +------------------------------------------------------------------+
   |   +-- Length of structure (LLLL)                                 |
   |   |                                                              |
   |   |    +-- GDS identifier                                        |
   |   |    |                                                         |
   |   |    |    +-- Data flow record                                 |
   |   |    |    |                                                    |
   |   |    |    |   +-- Length of pass-through specific header (LL)  |
   |   |    |    |   |                                                |
   |   |    |    |   |   +-- Flags                                    |
   |   |    |    |   |   |                                            |
   |   |    |    |   |   |   +-- Printer operation code               |
   |   |    |    |   |   |   |                                        |
   |   |    |    |   |   |   |      +-- Diagnostic field - zero pad to|
   |   |    |    |   |   |   |      |   LL specified                  |
   |   |    |    |   |   |   |      |                                 |
   |   |    |    |   |   |   |      |            +-- Printer data     |
   |   |    |    |   |   |   |      |            |                    |
   | +--+ +--+ +--+ ++ +--+ ++ +----------+ +----------------+        |
   | |  | |  | |  | || |  | || |          | |                |        |
   | xxxx 12A0 xxxx xx xxxx xx xxxxxxxxxxxx ... print data ...        |
   |                                                                  |
   +------------------------------------------------------------------+

           Figure 3.  Layout of the printer pass-through header

   BYTES 0-1:   Length of structure including this field (LLLL)

   BYTES 2-3:   GDS Identifier ('12A0'X)

   BYTE 4-5:    Data flow record

                This field contains flags that describe what type of
                data pass-through should be expected to be found
                following this header.  Generally, bits 0-2 in the first
                byte are mutually exclusive (that is, if one of them is



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                set to '1'B, the rest will be set to '0'B.) The bits and
                their meanings follow.

                BIT       DESCRIPTION

                0         Start-Up confirmation
                1         Termination record
                2         Start-Up Record
                3         Diagnostic information included
                4 - 5     Reserved
                6         Reserved
                7         Printer record
                8 - 13    Reserved
                14        Client-originated (inbound) printer record
                15        Server-originated (outbound) printer record

   BYTE 6:      Length printer pass-through header including this field
                (LL)

   BYTES 7-8:   Flags

     BYTE 7 BITS:  xxxx x111 --> Reserved
                   xxxx 1xxx --> Last of chain
                   xxx1 xxxx --> First of chain
                   xx1x xxxx --> Printer now ready
                   x1xx xxxx --> Intervention Required
                   1xxx xxxx --> Error Indicator

     BYTE 8 BITS:  xxxx xxxx --> Reserved

   BYTE 9:      Printer operation code

                '01'X  Print/Print complete
                '02'X  Clear Print Buffers

   BYTE 10-LL:  Diagnostic information (Note 1)

     If BYTE 7 = xx1x xxxx, then bytes 10-LL may contain:
        Printer ready                C9 00 00 00 02

     If BYTE 7 = x1xx xxxx, then bytes 10-LL may contain: (Note 2)
        Command/parameter not valid  C9 00 03 02 2x
        Print check                  C9 00 03 02 3x
        Forms check                  C9 00 03 02 4x
        Normal periodic condition    C9 00 03 02 5x
        Data stream error            C9 00 03 02 6x
        Machine/print/ribbon check   C9 00 03 02 8x




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     If BYTE 7 = 1xxx xxxx, then bytes 10-LL may contain: (Note 3)
        Cancel                       08 11 02 00
        Invalid print parameter      08 11 02 29
        Invalid print command        08 11 02 28

   Diagnostic information notes:

   1.  LL is the length of the structure defined in Byte 6.  If no
       additional data is present, the remainder of the structure must
       be padded with zeroes.

   2.  These are printer SIGNAL commands.  Further information on these
       commands may be obtained from the 5494 Remote Control Unit
       Functions Reference guide [5494-CU].  Refer to your iSeries
       printer documentation for more specific information on these data
       stream exceptions.  The following are some 3812 and 5553 errors
       that may be seen:

       Machine check              C9 00 03 02 11
       Graphics check             C9 00 03 02 26
       Print check                C9 00 03 02 31
       Form jam                   C9 00 03 02 41
       Paper jam                  C9 00 03 02 47
       End of forms               C9 00 03 02 50
       Printer not ready          C9 00 03 02 51
       Data stream - class 1      C9 00 03 02 66 loss of text
       Data stream - class 2      C9 00 03 02 67 text appearance
       Data stream - class 3      C9 00 03 02 68 multibyte control error
       Data stream - class 4      C9 00 03 02 69 multibyte control parm
       Cover unexpectedly open    C9 00 03 02 81
       Machine check              C9 00 03 02 86
       Machine check              C9 00 03 02 87
       Ribbon check               C9 00 03 02 88

   3.  These are printer negative responses.  Further information on
       these commands may be obtained from the 5494 Remote Control Unit
       Functions Reference guide [5494-CU].

       The print data will start in byte LL+1.

11.1.  Example of a Print Record

   Figure 4 shows the server sending the client data with a print
   record.  This is normally seen following receipt of a Success
   Response Record, such as the example in Figure 1.






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  +--------------------------------------------------------------------+
  |   +-- Length of structure (LLLL)                                   |
  |   |    +-- GDS identifier                                          |
  |   |    |    +-- Data flow record                                   |
  |   |    |    |   +-- Length of pass-through specific header (LL)    |
  |   |    |    |   |   +-- Flags                                      |
  |   |    |    |   |   |   +-- Printer operation code                 |
  |   |    |    |   |   |   |      +-- Zero pad to LL specified (0A)   |
  |   |    |    |   |   |   |      |            +-- Printer data       |
  |   |    |    |   |   |   |      |            |                      |
  | +--+ +--+ +--+ ++ +--+ ++ +----------+ +---------------------------|
  | |  | |  | |  | || |  | || |          | |                           |
  | 0085 12A0 0101 0A 1800 01 000000000000 34C4012BD20345FF2BD2044C0002|
  |                                                                    |
  | ------------------------------------------------------------       |
  |                                                                    |
  | 2BD2040D00002BD20A8501010201030204022BD20309022BD2061100014A       |
  |                                                                    |
  | ------------------------------------------------------------       |
  |                                                                    |
  | 402BD20601010000012BD306F60000FFFF2BD20A48000001000000010100       |
  |                                                                    |
  | ------------------------------------------------------------       |
  |                                                                    |
  | 2BD10705000B0090012BD2044900F02BD206404A403DE02BD2041500F034       |
  |                                                                    |
  |    end of printer data                                             |
  | -------------------------+                                         |
  |                          |                                         |
  | C4012BD10381FF002BC8034001                                         |
  +--------------------------------------------------------------------+

          Figure 4.  Server sending client data with a print record

   - '0085'X         = Logical record length, including this byte (LLLL)
   - '12A0'X         = GDS LU6.2 header
   - '0101'X         = Data flow record (server to client)
   - '0A'X           = Length of pass-through specific header (LL)
   - '1800'X         = First of chain / Last of chain indicators
   - '01'X           = Print
   - '000000000000'X = Zero pad header to LL specified
   - '34C401'X       = First piece of data for spooled data
   - Remainder is printer data/commands/orders








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RFC 4777           IBM's iSeries Telnet Enhancements       November 2006


11.2.  Example of a Print Complete Record

   Figure 5 shows the client sending the server a print complete record.
   This would normally follow receipt of a print record, such as the
   example in Figure 4.  This indicates successful completion of a print
   request.

   +-------------------------------------------------------------------+
   |   +-- Length of structure (LLLL)                                  |
   |   |    +-- GDS identifier                                         |
   |   |    |    +-- Data flow record                                  |
   |   |    |    |   +-- Length of pass-through specific header (LL)   |
   |   |    |    |   |   +-- Flags                                     |
   |   |    |    |   |   |   +-- Printer operation code                |
   |   |    |    |   |   |   |                                         |
   | +--+ +--+ +--+ ++ +--+ ++                                         |
   | |  | |  | |  | || |  | ||                                         |
   | 000A 12A0 0102 04 0000 01                                         |
   +-------------------------------------------------------------------+

         Figure 5.  Client sending server a print complete record

   - '000A'X = Logical record length, including this byte (LLLL)
   - '12A0'X = GDS LU6.2 header
   - '0102'X = Data flow response record (client to server)
   - '04'X   = Length of pass-through specific header (LL)
   - '0000'X = Good Response
   - '01'X   = Print Complete

11.3.  Example of a Null Print Record

   Figure 6 shows the server sending the client a null print record.
   The null print record is the last print command the server sends to
   the client for a print job, and it indicates to the printer that
   there is no more data.  The null data byte '00'X is optional and in
   some cases may be omitted (in particular, this scenario occurs in
   DBCS print streams).

   This example would normally follow any number of print records, such
   as the example in Figure 4.  This indicates successful completion of
   a print job.  The client normally responds to this null print record
   with another print complete record, such as in Figure 5.









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   +------------------------------------------------------------------+
   |   +-- Length of structure (LLLL)                                 |
   |   |    +-- GDS identifier                                        |
   |   |    |    +-- Data flow record                                 |
   |   |    |    |   +-- Length of pass-through specific header (LL)  |
   |   |    |    |   |   +-- Flags                                    |
   |   |    |    |   |   |   +-- Printer operation code               |
   |   |    |    |   |   |   |      +-- Zero pad to LL specified (0A) |
   |   |    |    |   |   |   |      |        +-- Printer data         |
   |   |    |    |   |   |   |      |        |                        |
   | +--+ +--+ +--+ ++ +--+ ++ +----------+ ++                        |
   | |  | |  | |  | || |  | || |          | ||                        |
   | 0011 12A0 0101 0A 0800 01 000000000000 00                        |
   +------------------------------------------------------------------+

           Figure 6.  Server sending client a null print record

   - '0011'X         = Logical record length, including this byte
   - '12A0'X         = GDS LU6.2 header
   - '0101'X         = Data flow record
   - '0A'X           = Length of pass-through specific header (LL)
   - '0800'X         = Last of Chain
   - '01'X           = Print
   - '000000000000'X = Zero pad header to LL specified
   - '00'X           = Null data byte


























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RFC 4777           IBM's iSeries Telnet Enhancements       November 2006


12.  End-to-End Print Example

   The next example shows a full print exchange between a Telnet client
   and server for a 526 byte spooled file.  Selective translation of the
   hexadecimal streams into 1) Telnet negotiations and 2) ASCII/EBCDIC
   characters is done to aid readability.  Telnet negotiations are
   delimited by '(' and ')' parenthesis characters; ASCII/EBCDIC
   conversions are bracketed by '|' vertical bar characters.

   iSeries Telnet server               Enhanced Telnet client
   -------------------------------     ---------------------------------
   FFFD27                          -->

   (IAC DO NEW-ENVIRON)
                                   <-- FFFB27

                                       (IAC WILL NEW-ENVIRON)

   FFFD18FFFA270103 49424D5253454544
   7EA5DFDDFD300404 0003FFF0       -->

   (IAC DO TERMINAL-TYPE
   IAC SB NEW-ENVIRON SEND USERVAR
   IBMRSEED xxxxxxxx VAR USERVAR
   IAC SE)

                                   <-- FFFB18

                                       (IAC WILL TERMINAL-TYPE)

   FFFA1801FFF0                    -->

   (IAC SB TERMINAL-TYPE SEND IAC
    SE)

                                       FFFA27000349424D 52534545447EA5DF
                                       DDFD300404000344 45564E414D450144
                                       554D4D5950525403 49424D4D5347514E
                                       414D450151535953 4F50520349424D4D
                                       5347514C4942012A 4C49424C0349424D
                                       464F4E5401313103 49424D5452414E53
                                       464F524D01310349 424D4D4652545950
                                       4D444C012A485049 490349424D505052
                                       5352433101020103 49424D5050525352
                                       433201040349424D 454E56454C4F5045
                                       01FFFF0349424D41 5343494938393901
                                   <-- 30FFF0




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RFC 4777           IBM's iSeries Telnet Enhancements       November 2006


                                       (IAC SB NEW-ENVIRON IS USERVAR
                                        IBMRSEED xxxxxxxx VAR
                                        USERVAR DEVNAME VALUE DUMMYPRT
                                        USERVAR IBMMSGQNAME VALUE
                                        QSYSOPR
                                        USERVAR IBMMSGQLIB VALUE *LIBL
                                        USERVAR IBMFONT VALUE 11
                                        USERVAR IBMTRANSFORM VALUE 1
                                        USERVAR IBMMFRTYPMDL VALUE *HPII
                                        USERVAR IBMPPRSRC1 VALUE
                                        ESC '01'X
                                        USERVAR IBMPPRSRC2 VALUE '04'X
                                        USERVAR IBMENVELOPE VALUE IAC
                                        USERVAR IBMASCII899 VALUE 0
                                        IAC SE)

                                   <-- FFFA180049424D2D 333831322D31FFF0

                                       (IAC SB TERMINAL-TYPE IS
                                        IBM-3812-1 IAC SE)
   FFFD19                          -->

   (IAC DO EOR)
                                   <-- FFFB19

                                       (IAC WILL EOR)

   FFFB19                          -->

   (IAC WILL EOR)
                                   <-- FFFD19

                                       (IAC DO EOR)
   FFFD00                          -->

   (IAC DO BINARY)
                                   <-- FFFB00

                                       (IAC WILL BINARY)
   FFFB00                          -->

   (IAC WILL BINARY)
                                   <-- FFFD00

                                       (IAC DO BINARY)






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RFC 4777           IBM's iSeries Telnet Enhancements       November 2006


   004912A090000560 060020C0003D0000     |       -   {    |
   C9F9F0F2C5D3C3D9 E3D7F0F6C4E4D4D4     |I902ELCRTP06DUMM| (EBCDIC)
   E8D7D9E340400000 0000000000000000     |YPRT            |
   0000000000000000 0000000000000000     |                |
   0000000000000000 00FFEF           --> |                |

   (73-byte startup success response
    record ... IAC EOR)
   00DF12A001010A18 0001000000000000     |                |
   03CD1B451B283130 551B287330703130     |   E (10U (s0p10| (ASCII)
   2E30306831327630 733062303033541B     |.00h12v0s0b003T |
   287330421B266440 1B266C304F1B266C     |(s0B &d@ &l0O &l|
   303038431B266C30 3035431B28733070     |008C &l005C (s0p|
   31372E3130683130 7630733062303030     |17.10h10v0s0b000|
   541B283130551B28 73307031372E3130     |T (10U (s0p17.10|
   6831307630733062 303030541B287330     |h10v0s0b000T (s0|
   421B2664401B266C 314F1B266C303035     |B &d@ &l1O &l005|
   431B287330703137 2E31306831307630     |C (s0p17.10h10v0|
   733062303030541B 266C314F1B287330     |s0b000T &l1O (s0|
   7031372E31306831 3076307330623030     |p17.10h10v0s0b00|
   30541B2873307031 372E313068313076     |0T (s0p17.10h10v|
   3073306230303054 1B266C30303543FF     |0s0b000T &l005C |
   EF                                --> |                |

   (... 223-byte print record ...
    ... first of chain ...
    ... last of chain ... IAC EOR)
                                     <-- 000A12A001020400 0001FFEF

                                         (10-byte print complete header)
   031012A001010A10 0001000000000000     |                |
   03FFFF1B451B2831 30551B2873307031     |    E (10U (s0p1| (ASCII)
   372E313068313076 3073306230303054     |7.10h10v0s0b000T|
   1B287330421B2664 401B266C314F1B26     | (s0B &d@ &l1O &|
   6C303035431B266C 31481B266C314F1B     |l005C &l1H &l1O |
   266C3032411B266C 31431B266C303030     |&l02A &l1C &l000|
   38451B266C303038 431B266C30303439     |8E &l008C &l0049|
   461B266130521B26 6C303035430A0A0A     |F &a0R &l005C   |
   0A0A0A0A1B26612B 3030303130561B26     |     &a+00010V &|
   6C303035431B2661 2B30303231364820     |l005C &a+00216H |
   2020202020202020 2020202020202020     |                |
   2020202020205072 696E74204B657920     |      Print Key |
   4F75747075742020 2020202020202020     |Output          |
   2020202020202020 2020202020202020     |                |
   2020202020205061 6765202020310D0A     |      Page   1  |
   1B26612B30303231 3648202020203537     | &a+00216H    57|
   3639535331205634 52334D3020393830     |69SS1 V4R3M0 980|
   373203FFFF392020 2020202020202020     |72   9          |



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RFC 4777           IBM's iSeries Telnet Enhancements       November 2006


   202020202020454C 4352545030362020     |      ELCRTP06  |
   2020202020202020 202030332F33312F     |          03/31/|
   3939202031363A33 303A34350D0A1B26     |99  16:30:45   &|
   612B303032313648 0D0A1B26612B3030     |a+00216H   &a+00|
   3231364820202020 446973706C617920     |216H    Display |
   4465766963652020 2E202E202E202E20     |Device  . . . . |
   2E203A2020515041 444556303033510D     |. :  QPADEV003Q |
   0A1B26612B303032 3136482020202055     |  &a+00216H    U|
   73657220202E202E 202E202E202E202E     |ser  . . . . . .|
   202E202E202E202E 203A202052434153     | . . . . :  RCAS|
   54524F0D0A1B2661 2B3030323136480D     |TRO   &a+00216H |
   0A1B26612B303032 313648204D41494E     |  &a+00216H MAIN|
   2020202020202020 2020202020202020     |                |
   2020202020202020 20202041532F3430     |           AS/40|
   30204D61696E204D 656E750D0A1B2661     |0 Main Menu   &a|
   2B30303203FFFF31 3648202020202020     |+002   16H      |
   2020202020202020 2020202020202020     |                |
   2020202020202020 2020202020202020     |                |
   2020202020202020 2020202020202020     |                |
   2020202020202053 797374656D3A2020     |       System:  |
   20454C4352545030 360D0A1B26612B30     | ELCRTP06   &a+0|
   3032313648205365 6C656374206F6E65     |0216H Select one|
   206F662074686520 666F6C6C6F77696E     | of the followin|
   673A0D0A1B26612B 3030323136480D0A     |g:   &a+00216H  |
   1B26612B30303231 3648202020202020     | &a+00216H      |
   312E205573657220 7461736B730D0A1B     |1. User tasks   |
   26612B3030323136 4820202020202032     |&a+00216H      2|
   2E204F6666696365 207461736B730D0A     |. Office tasks  |
   1B26612B30303231 36480D0A1B26612B     | &a+00216H   &a+|
   3030323136482020 20202020342E2046     |00216H      4. F|
   696C65732C206C69 627261726965732C     |iles, libraries,|
   20616EFFEF                            | an             |

   (... 784-byte print record ...
    ... first of chain ... IAC EOR)
                                     <-- 000A12A001020400 0001FFEF

                                         (10-byte print complete header)

   020312A001010A00 0001000000000000     |                |
   64206603FFFF6F6C 646572730D0A1B26     |d f   olders   &| (ASCII)
   612B303032313648 0D0A1B26612B3030     |a+00216H   &a+00|
   3231364820202020 2020362E20436F6D     |216H      6. Com|
   6D756E6963617469 6F6E730D0A1B2661     |munications   &a|
   2B3030323136480D 0A1B26612B303032     |+00216H   &a+002|
   3136482020202020 20382E2050726F62     |16H      8. Prob|
   6C656D2068616E64 6C696E670D0A1B26     |lem handling   &|
   612B303032313648 202020202020392E     |a+00216H      9.|



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RFC 4777           IBM's iSeries Telnet Enhancements       November 2006


   20446973706C6179 2061206D656E750D     | Display a menu |
   0A1B26612B303032 3136482020202020     |  &a+00216H     |
   31302E20496E666F 726D6174696F6E20     |10. Information |
   417373697374616E 74206F7074696F6E     |Assistant option|
   730D0A1B26612B30 3032313648202020     |s   &a+00216H   |
   202031312E20436C 69656E7420416363     |  11. Client Acc|
   6573732F34303020 7461736B730D0A1B     |ess/400 tasks   |
   26612B3030323136 480D0A1B26612B30     |&a+00216H   &a+0|
   303231364803ED20 2020202039302E20     |0216H       90. |
   5369676E206F6666 0D0A1B26612B3030     |Sign off   &a+00|
   323136480D0A1B26 612B303032313648     |216H   &a+00216H|
   2053656C65637469 6F6E206F7220636F     | Selection or co|
   6D6D616E640D0A1B 26612B3030323136     |mmand   &a+00216|
   48203D3D3D3E0D0A 1B26612B30303231     |H ===>   &a+0021|
   36480D0A1B26612B 3030323136482046     |6H   &a+00216H F|
   333D457869742020 2046343D50726F6D     |3=Exit   F4=Prom|
   707420202046393D 5265747269657665     |pt   F9=Retrieve|
   2020204631323D43 616E63656C202020     |   F12=Cancel   |
   4631333D496E666F 726D6174696F6E20     |F13=Information |
   417373697374616E 740D0A1B26612B30     |Assistant   &a+0|
   3032313648204632 333D53657420696E     |0216H F23=Set in|
   697469616C206D65 6E750D0A1B26612B     |itial menu   &a+|
   3030323136480D0A 1B26612B30303231     |00216H   &a+0021|
   36480D0CFFEF                          |6H              |

   (... 515-byte print record ...
    IAC EOR)
                                     <-- 000A12A001020400 0001FFEF

                                         (10-byte print complete header)
   001412A001010A00 0001000000000000     |                |
   03021B45FFEF                          |   E            |  (ASCII)

   (... 20-byte print record ...
    IAC EOR)
                                     <-- 000A12A001020400 0001FFEF

                                         (10-byte print complete header)
   001112A001010A08 0001000000000000
   00FFEF                            -->

   (... 17-byte NULL print record ...
    ... last of chain ... IAC EOR)
                                     <-- 000A12A001020400 0001FFEF

                                         (10-byte print complete header)





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RFC 4777           IBM's iSeries Telnet Enhancements       November 2006


13.  Security Considerations

   The auto-sign-on feature provided by this RFC describes a way to
   encrypt your login password.  However, while passwords can now be
   encrypted by using the IBMRSEED and IBMSUBSPW USERVAR negotiations,
   users should understand that only the login passwords are encrypted
   and not the entire Telnet session.  Encryption of the Telnet session
   requires that another protocol layer, such as SSL, be added.

   The auto-sign-on feature supports plain text passwords, encrypted
   passwords, and Kerberos tokens.  However, using plain text passwords
   is strongly discouraged.  iSeries system administrators may want to
   configure their systems to reject plain text passwords.

14.  IANA Considerations

   IANA registered the terminal types "IBM-3812-1" and "IBM-5553-B01" as
   a terminal type [RFC1091].  They are used when communicating with
   iSeries Telnet servers.

15.  Normative References

   [RFC854]      Postel, J. and J. Reynolds, "Telnet Protocol
                 Specification", STD 8, RFC 854, May 1983.

   [RFC855]      Postel, J. and J. Reynolds, "Telnet Option
                 Specifications", STD 8, RFC 855, May 1983.

   [RFC1091]     VanBokkelen, J., "Telnet terminal-type option", RFC
                 1091, February 1989.

   [RFC1205]     Chmielewski, P., "5250 Telnet Interface", RFC 1205,
                 February 1991.

   [RFC1572]     Alexander, S., "Telnet Environment Option", RFC 1572,
                 January 1994.

   [RFC2877]     Murphy, T., Jr., Rieth, P., and J. Stevens, "5250
                 Telnet Enhancements", RFC 2877, July 2000.

16.  Informative References

   [RFC856]      Postel, J. and J. Reynolds, "Telnet Binary
                 Transmission", STD 27, RFC 856, May 1983.

   [RFC858]      Postel, J. and J. Reynolds, "Telnet Supress Go Ahead
                 Option", STD 29, RFC 858, May 1983.




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RFC 4777           IBM's iSeries Telnet Enhancements       November 2006


   [RFC885]      Postel, J., "Telnet end of record option", RFC 885,
                 December 1983.

   [5494-CU]     IBM, "5494 Remote Control Unit, Functions Reference",
                 SC30-3533-04, August 1995.

   [SYSTEM-API]  IBM, "AS/400 System API Reference", SC41-5801-01,
                 February 1998.

   [COMM-CONFIG] IBM, "AS/400 Communications Configuration",
                 SC41-5401-00, August 1997.

   [NLS-SUPPORT] IBM, "AS/400 National Language Support", SC41-5101-01,
                 February 1998.

   [FIPS-46-2]   Data Encryption Standard (DES), Federal Information
                 Processing Standards Publication 46-2, January 22,
                 1988.

   [FIPS-81]     DES Modes of Operation, Federal Information Processing
                 Standards Publication 81, December 1980.

   [FIPS-180-1]  Secure Hash Standard, Federal Information Processing
                 Standards Publication 180-1, May 11, 1993.

17.  Relation to Other RFCs

   This RFC relies on the 5250 Telnet Interface [RFC1205] in all
   examples.

   This RFC replaces 5250 Telnet Enhancements [RFC2877], adding new
   sections for Kerberos, SHA-1, security and IANA considerations.
   Minor corrections and additional examples were also added.

   Informative references have been removed.
















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RFC 4777           IBM's iSeries Telnet Enhancements       November 2006


Authors' Addresses

   Thomas E. Murphy, Jr.
   IBM Corporation
   2455 South Road
   Poughkeepsie, NY 12601

   Phone:  (845) 435-7063
   Fax:    (845) 432-9414
   EMail:  murphyte@us.ibm.com


   Paul F. Rieth
   IBM Corporation
   3605 Highway 52 North
   Rochester, MN 55901

   Phone:  (507) 253-5218
   Fax:    (507) 253-5156
   EMail:  rieth@us.ibm.com


   Jeffrey S. Stevens
   IBM Corporation
   3605 Highway 52 North
   Rochester, MN 55901

   Phone:  (507) 253-5337
   Fax:    (507) 253-5156
   EMail:  jssteven@us.ibm.com





















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Full Copyright Statement

   Copyright (C) The IETF Trust (2006).

   This document is subject to the rights, licenses and restrictions
   contained in BCP 78 and at www.rfc-editor.org/copyright.html, and
   except as set forth therein, the authors retain all their rights.

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   "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
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Acknowledgement

   Funding for the RFC Editor function is currently provided by the
   Internet Society.






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