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VT Emulation not immediate?

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(@djdachtera)
Active Member
Joined: 9 years ago
Posts: 9
Topic starter  

Hi, Brian,

As we've been preparing to roll out AT, I've noticed that during the SSH2 login dialogue, VT emulation appears to not be active.

For example...

Running in FIPS 140-2 Mode
Validating FIPS certified DLL...Passed

Connecting to mis65a:22
attempting 10.49.45.3:22... Success!
Username: system

[H[2J[1;24r[0m(0[1m qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq(B
CORAM - Corporate VAXcluster VAX/VMS v6.2
Leaders in Alternate-Site Health-Care Services and Products
Service Desk Phone Number: 1-855-280-4872.
(0 qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq(B[0m
***********************************************************************
Coram/Mount Prospect System Availability
Mon, Tues, Wed, Thur, Last Day of Month 6:00AM CST to 9:30PM CST
Friday 6:00AM CST to 9:00PM CST
Saturday (Including Last Day of Month) 6:00AM CST to 8:00PM CST
1st Day of Month After Month End Completion
********************************************************************
|IF YOUR VAX SCREEN IS FROZEN, DO NOT END YOUR KEA SESSION BY ANY METHOD!|
|DO NOT USE FILE>Exit or EXIT All |
|DO NOT USE Tools>Connection>Disconnect |
|DO NOT USE "X" IN THE UPPER RIGHT HAND CORNER |
|DO NOT REBOOT OR LOGOFF YOUR PC! |
|DOING SO WILL RESULT IN SYSTEM PERFORMANCE ISSUES FOR ALL USERS |

Please call the Service Desk. Tell the Service Desk Agent you are logged on
to Corprorate, your Username, the application you are running (CARS, etc.)
and the frozen screen. They will stop your session without impacting others.

Thank you for your assistance in this matter.

Password:

At this point, AT is (attempting to) display(ing) the escape sequences for line drawing characters instead of interpreting and obeying them.

Then, the system has a command, "SET TERMINAL/INQUIRE" which is used to send ANSI-compliant escape sequences to the terminal to find out it's characteristics, emulation mode, etc. It appears those data are being both displayed AND interpreted...

Authentication SUCCESS
Allocating PTY... SUCCESS
Start X11 forwarding... Skipped
Starting authentication agent... FAIL
Starting shell... SUCCESS

Last interactive login on Friday, 15-JAN-2016 13:41:30.31
Last non-interactive login on Friday, 15-JAN-2016 13:47:09.41

You have 12 new Mail messages.

Setting Terminal Type...
>
__?~????/??@B????;
???oOOOO/???N????;
OOOOOOOO/????????;
???}@@A?/???N????;
???~????/CGGF????;
???~????/???N????;
???}AAA?/???N????;
???~????/???FCCC?;
AAA}????/???N????;
???~????/CCCF????;
???{A@??/???N????;
???~????/???BCG??;
?@A{????/???N????;
???~????/?GCB????;
?_ON????/??@M????;
???NO_??/???M@???;
???OoOOO/?????@AC;
???OWSQP/????????;
@ACGO_??/??????@?;
???_OGC?/CA@?????;
OOOOOOo?/??????@?;
OOOOOO[?/????????;
@ACGo???/GCA@????;
?}AAA???/?BAAA???;
??WWW???/????????;
??AAA}??/??AAAB??;
GGG}GGG?/AAAAAAA?;
?OWSQOO?/?@@@@@@?;
?ggwkig?/?A@?????;
?OOQSWO?/?@@@@@@?;
???}@@A?/CGGF????;
???KK???/?BB??BB?;
wCCwCCC?/?@@?@@@?;
wCCwCCw?/?@@?@@??;
OOOSOOO?/???@????;
?oKAKo??/BAAAAAB?;
KScCcSK?/???@????;
Wcd~dcW?/??ABA???;
?@~@@B??/?ABA????;
OGGO__O?/????????;
GCCGOOG?/@@@@@@@?;
wCQQQCw?/?@AAA@??;
?CgOgC??/?@???@??;
?oKAKo??/BA???AB?;
gkigikg?/?@A?A@??;
?gggikg?/????A@??;
?gggggg?/?AAAAAA?;
A}AAA}A?/?B???B??;
MO_}_OM?/??ABA???;
?CIIIC??/????????;
AEiQAAA?/ABAAAAA?;
?SiiiO??/??AAA@??;
?KQQ}Q}?/????B?B?;
_??_WEA?/?@A@????;
wCAAACw?/AB???BA?;
?AQQQQA?/?AAAAAA?;
CAA{AAC?/???B????;
oGCCCCC?/?@AAAAA?;
CCCCCGo?/AAAAA@??;
wCAAACw?/B?????B?;
}?????}?/?@AAA@??;
?oKAKo??/B?????B?;
EW_?_WE?/??@A@???;
?GGGGGW?/????????;
_OGGoOG?/?@AA@@A?;
?_WSQQk?/E@AAAA@?;
?GGO__W?/GCA@?@M?;
?_O[QaC?/?@AAA@??;
?ogggG??/?@AAAA??;
_OOOoOg?/HEABAA@?;
GCGo?_O?/??KN@???;
GGoOGGo?/??B???N?;
???w????/???@AA@?;
oggggo??/@AAAA@??;
C{?_OG??/?B@@AA??;
?CCgO_??/AA@???B?;
?w????w?/E@AAAA@?;
CcW??_[?/ABA@@???;
CCcSGGo?/??@AAA@?;
?GwGGwG?/?A@??B??;
_??w??_?/?@ANA@??;
??_OGGo?/KB??@@??;
_OGGWgG?/@AAAA@??;
OGGwGGC?/???BA???;
????????/????????;
???}PPA?/EGGF????;
oG?_?Go?/@AA@AA@?;
OgicCC??/?BAIIE??;
Cw????w?/??@AA@??;
cQIEEAA?/?@@DDB??;
OwSOOOO?/??@?????;
?GC}CG??/???B????;
OOOOSwO?/????@???;
?_?}?_??/??@B@???;

Type SYSMENU for system menu options
Type FMENU for field menu options
$

Once the host system's command prompt appears, then everything appears to function as expected...

$ TYPE ANNOUNCE.TXT
───────────────────────────────────────────────────────────────────
CORAM - Corporate VAXcluster VAX/VMS v6.2
Leaders in Alternate-Site Health-Care Services and Products
Service Desk Phone Number: 1-855-280-4872.
───────────────────────────────────────────────────────────────────
********************************************************************
Coram/Mount Prospect System Availability
Mon, Tues, Wed, Thur, Last Day of Month 6:00AM CST to 9:30PM CST
Friday 6:00AM CST to 9:00PM CST
Saturday (Including Last Day of Month) 6:00AM CST to 8:00PM CST
1st Day of Month After Month End Completion
***********************************************************************
|IF YOUR VAX SCREEN IS FROZEN, DO NOT END YOUR KEA SESSION BY ANY METHOD!|
|DO NOT USE FILE>Exit or EXIT All |
|DO NOT USE Tools>Connection>Disconnect |
|DO NOT USE "X" IN THE UPPER RIGHT HAND CORNER |
|DO NOT REBOOT OR LOGOFF YOUR PC! |
|DOING SO WILL RESULT IN SYSTEM PERFORMANCE ISSUES FOR ALL USERS |

Please call the Service Desk. Tell the Service Desk Agent you are logged on
to Corprorate, your Username, the application you are running (CARS, etc.)
and the frozen screen. They will stop your session without impacting others.

Thank you for your assistance in this matter.
$ set term/inq
$

Just wanted to let you know. Again this is AT V9.82


   
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(@bpence)
Member Admin
Joined: 11 months ago
Posts: 1375
 

Has it always done this or did it recently start?

Can you verify that the terminal type is set correctly initially? Before login, check options->properties->VTOptions-:TerminalType

Without more details, I may require a logfile to determine what's going on.

Brian


   
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(@djdachtera)
Active Member
Joined: 9 years ago
Posts: 9
Topic starter  

As far as I know, this has been from the beginning of our experience with V9.82.

I'm not sure how to paste in a screen shot. so let me try to attach it, instead...

This has worked for (literally) decades with both Attachmate KEA! and WRQ Reflection (now also owned by Attachmate / Micro Focus).


   
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(@djdachtera)
Active Member
Joined: 9 years ago
Posts: 9
Topic starter  

TELNET log in has the same problem.


   
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(@bpence)
Member Admin
Joined: 11 months ago
Posts: 1375
 

I think part of this at least is related to the 'issue' message that is apparently inserted between the 'login' and 'password' prompts. See if the contents of the '/etc/issue' file are the same as what you're seeing on-screen. In SSH, this is done by squeezing the entire /etc/issue into the password prompt. It's possible the prompt *may* not be processed for escape sequences, so I'll look into that.

The portion *after* the login should just be interpreted as terminal data, so I'm not sure why it also displays. I'll need a logfile for that if you can send me one.

Use File->Open Log before logging in
Then File->Close LOG once you're all the way in.

Zip the resulting logfile and mail it to: bpence@celestialsoftware.net

I'll let you know what I find.

Brian


   
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(@bpence)
Member Admin
Joined: 11 months ago
Posts: 1375
 

I would expect 'telnet' to have the second problem but not the first. Can you give me a full output of the telnet connection sequence?

B


   
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(@djdachtera)
Active Member
Joined: 9 years ago
Posts: 9
Topic starter  

this is from a TELNET login...

Connecting to mis64a:23
attempting 10.49.45.4:23... Success!

-------------------------------------------------------------------
CORAM - Corporate VAXcluster VAX/VMS v6.2
Leaders in Alternate-Site Health-Care Services and Products
Service Desk Phone Number: 1-855-280-4872.
-------------------------------------------------------------------
Coram/Mount Prospect System Availability
Mon, Tues, Wed, Thur, Last Day of Month 6:00AM CST to 9:30PM CST
Friday 6:00AM CST to 9:00PM CST
Saturday (Including Last Day of Month) 6:00AM CST to 8:00PM CST
1st Day of Month After Month End Completion
--------------------------------------------------------------------------
|IF YOUR VAX SCREEN IS FROZEN, DO NOT END YOUR KEA SESSION BY ANY METHOD!|
|DO NOT USE FILE>Exit or EXIT All |
|DO NOT USE Tools>Connection>Disconnect |
|DO NOT USE "X" IN THE UPPER RIGHT HAND CORNER |
|DO NOT REBOOT OR LOGOFF YOUR PC! |
|DOING SO WILL RESULT IN SYSTEM PERFORMANCE ISSUES FOR ALL USERS |

Please call the Service Desk. Tell the Service Desk Agent you are logged on
to Corprorate, your Username, the application you are running (CARS, etc.)
and the frozen screen. They will stop your session without impacting others.

Thank you for your assistance in this matter.
Username: SYSTEM
Password:
Welcome to OpenVMS VAX version V6.2 on node MIS64A
Last interactive login on Friday, 15-JAN-2016 13:47
Last non-interactive login on Friday, 15-JAN-2016 14:17

You have 12 new Mail messages.

Setting Terminal Type...
>
__?~????/??@B????;
???oOOOO/???N????;
OOOOOOOO/????????;
???}@@A?/???N????;
???~????/CGGF????;
???~????/???N????;
???}AAA?/???N????;
???~????/???FCCC?;
AAA}????/???N????;
???~????/CCCF????;
???{A@??/???N????;
???~????/???BCG??;
?@A{????/???N????;
???~????/?GCB????;
?_ON????/??@M????;
???NO_??/???M@???;
???OoOOO/?????@AC;
???OWSQP/????????;
@ACGO_??/??????@?;
???_OGC?/CA@?????;
OOOOOOo?/??????@?;
OOOOOO[?/????????;
@ACGo???/GCA@????;
?}AAA???/?BAAA???;
??WWW???/????????;
??AAA}??/??AAAB??;
GGG}GGG?/AAAAAAA?;
?OWSQOO?/?@@@@@@?;
?ggwkig?/?A@?????;
?OOQSWO?/?@@@@@@?;
???}@@A?/CGGF????;
???KK???/?BB??BB?;
wCCwCCC?/?@@?@@@?;
wCCwCCw?/?@@?@@??;
OOOSOOO?/???@????;
?oKAKo??/BAAAAAB?;
KScCcSK?/???@????;
Wcd~dcW?/??ABA???;
?@~@@B??/?ABA????;
OGGO__O?/????????;
GCCGOOG?/@@@@@@@?;
wCQQQCw?/?@AAA@??;
?CgOgC??/?@???@??;
?oKAKo??/BA???AB?;
gkigikg?/?@A?A@??;
?gggikg?/????A@??;
?gggggg?/?AAAAAA?;
A}AAA}A?/?B???B??;
MO_}_OM?/??ABA???;
?CIIIC??/????????;
AEiQAAA?/ABAAAAA?;
?SiiiO??/??AAA@??;
?KQQ}Q}?/????B?B?;
_??_WEA?/?@A@????;
wCAAACw?/AB???BA?;
?AQQQQA?/?AAAAAA?;
CAA{AAC?/???B????;
oGCCCCC?/?@AAAAA?;
CCCCCGo?/AAAAA@??;
wCAAACw?/B?????B?;
}?????}?/?@AAA@??;
?oKAKo??/B?????B?;
EW_?_WE?/??@A@???;
?GGGGGW?/????????;
_OGGoOG?/?@AA@@A?;
?_WSQQk?/E@AAAA@?;
?GGO__W?/GCA@?@M?;
?_O[QaC?/?@AAA@??;
?ogggG??/?@AAAA??;
_OOOoOg?/HEABAA@?;
GCGo?_O?/??KN@???;
GGoOGGo?/??B???N?;
???w????/???@AA@?;
oggggo??/@AAAA@??;
C{?_OG??/?B@@AA??;
?CCgO_??/AA@???B?;
?w????w?/E@AAAA@?;
CcW??_[?/ABA@@???;
CCcSGGo?/??@AAA@?;
?GwGGwG?/?A@??B??;
_??w??_?/?@ANA@??;
??_OGGo?/KB??@@??;
_OGGWgG?/@AAAA@??;
OGGwGGC?/???BA???;
????????/????????;
???}PPA?/EGGF????;
oG?_?Go?/@AA@AA@?;
OgicCC??/?BAIIE??;
Cw????w?/??@AA@??;
cQIEEAA?/?@@DDB??;
OwSOOOO?/??@?????;
?GC}CG??/???B????;
OOOOSwO?/????@???;
?_?}?_??/??@B@???;

Type SYSMENU for system menu options
Type FMENU for field menu options
$

Note that I edited the ANNOUNCE.TXT file to remove the VT escape sequences, but the SET TERMINAL/INQUIRE command still produces the voluminous "stuff".

I'm somewhat familiar with UN*X; so, I understand the /etc/issue reference. In our case, the file is found as SYS$MANAGER:ANNOUNCE.TXT.


   
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(@bpence)
Member Admin
Joined: 11 months ago
Posts: 1375
 

The function of the banner message, or in your case 'ANNOUNCE.TXT' will likely not be changing. According to RFC4252, control characters other than carriage return, newline, and tab should be ignored when seen there. This is what absolute does.

Still looking at the other "STUFF" spewed after login.

From RFC4252 regarding SSH_USERAUTH_BANNER

"If the 'message' string is displayed, control character filtering,
discussed in RFC4251, SHOULD be used to avoid attacks by sending
terminal control characters."

From RFC4251:

9.2. Control Character Filtering

When displaying text to a user, such as error or debug messages, the
client software SHOULD replace any control characters (except tab,
carriage return, and newline) with safe sequences to avoid attacks by
sending terminal control characters.


   
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(@djdachtera)
Active Member
Joined: 9 years ago
Posts: 9
Topic starter  

In so far as those may be true, they will limit the marketability of your product if you attempt to enforce current "standards" on systems developed before those "standards" existed. (Remember: "RFC" stands for "Request For Comments". "True" standards are issued by agencies like ANSI, ISO, SAE, IEEE, etc.)

These systems were developed in the days when users had VT terminals on their desks along side typewriters, calculators / adding machines, card tabulators, etc. Replacement systems are expected to be fully compatible with equipment they replace.

That said, of course, attempting to impose those "standards" results in code duplication on your part. In order to follow them, you must bypass your existing code which displays text/data from the host and instead filter that data thru code compliant with the RFCs. Defeats your purpose and that of the end user.

By comparision and for example, WRQ took a different approach (before Attachmate bought them and Reflection). The initial dialog between the SSH host and the user occurs through Windows message and dialogue boxes. Once completed, THEN the normal data / display paths are connected. Needless to say, text / message boxes do not provide emulation, either.

In AT, it appears to the user that they are interacting with the host during SSH negotiations which is, of course, not true.

Stated a different way, you may need to take a different approach to management of the user's perceptions.

For what it's worth...


   
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(@bpence)
Member Admin
Joined: 11 months ago
Posts: 1375
 

RFCs can be revised by newer RFCs on their way to becoming a standard, but they're the closest thing we've got and should really be followed as if they're the gospel. I found similar references in other products, such as putty, which implements the same solution:

[url] http://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/banner-escape-codes.html [/url]

Deferring the text to *after* the login is not a good idea, as part of the reason for the banner is to display a warning prior to authentication, usually for legal purposes. Another reason to avoid escapes is at this point in the connection sequence, no PTY or shell has been officially started, so the host doesn't really know the terminal type and may be providing invalid escape sequences for a particular terminal.

The solution is, of course, exactly what you already did.... Strip the escapes.

Brian


   
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(@bpence)
Member Admin
Joined: 11 months ago
Posts: 1375
 

Here's a software update that helps handle your situation....

This cleans up the output *after* login, though the text in the banner before login will *still* not parsed for escapes and is recommended to stay that way. This version does parse a previously unrecognized escape sequences that is intended to define bitmaps for new characters. Custom bitmap characters are still not supported, but now we at least recognize the escape sequence and discard it.

http://www.celestialsoftware.net/telnet/AbsoluteTelnet10.15RC1.exe

NOT defining the custom characters may cause trouble with other functionality down the line, particularly if the custom characters were later used. Let me know if you run into further issues.

Brian


   
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(@bpence)
Member Admin
Joined: 11 months ago
Posts: 1375
 

Did the 10.15 update help?

Brian


   
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(@bpence)
Member Admin
Joined: 11 months ago
Posts: 1375
 

Here's the (hopefully final) beta for 10.15, which includes this fix among other things. Please run this for a few days to help me ensure nothing else is broken before I release publicly.

http://www.celestialsoftware.net/telnet/AbsoluteTelnet10.15RC9.exe

Regards,

Brian


   
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(@bpence)
Member Admin
Joined: 11 months ago
Posts: 1375
 

Here's the final update for 10.15 (final release)

http://www.celestialsoftware.net/telnet/AbsoluteTelnet10.15.exe

Brian


   
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