# How to display authentication banner

When SSH authentication is used, the SSH_MSG_USERAUTH_BANNER message may be sent from server.
Basically, this message is shown on VT window. If display method is changed, please change AuthBanner entry of [TTSSH] section in the following:

    AuthBanner=<Display Method>

The display method can be specified from 0 to 3. Meaning of each value in the following:

Value | Action
--- | ---
0 | No display
1 | Display in VT window
2 | Display by pop-up
3 | Display by balloon tip

    Default:
    AuthBanner=1

# Suppressing message box

When Tera Term is automated by using macro or non-logon and the error and warning is occurred, the message box will be shown. Next, Tera Term waits user operation and the procedure can not be continued.
To prevent this problem, the message box can be suppressed.

    DisablePopupMessage=<Suppress Message>

The "Suppress Message" can be specified with the sum value of suppressing message type. Meaning of each value is as follows.

Value | Action
--- | ---
0 | Not suppress pop-up window
1 | Suppress "sending forwarded data to a local port error" pop-up message
2 | Suppress "SSH channel open error" pop-up window

    Default:
    DisablePopupMessage=0

# Minimum group size for Diffie-Hellman Group Exchange

When Diffie-Hellman Group Exchange(diffie-hellman-group-exchange-sha*) is used for key exchanging method, SSH client some requests of 'Minimum size', 'Proposed size' and 'Maximum size' regarding group to server.
As described below, current TTSSH sends 2048 as minimum size to server. When the group size sent from server is smaller than the minimu size, TTSSH shows the confirmation dialog whether the connection continues.

When the GexMinimalGroupSize entry of [TTSSH] section is changed below, the minimum size of group requesting to server.

    GexMinimalGroupSize=<Minimum size of group>

The minimum size of group can be specified with 0 and 1024 to 8192.
When the value is 0, TTSSH uses the optimal value. Current TTSSH sends 2048 in accordance with RFC 8270. The value will be changed in the future.
When the value is specified from 1024 to 8192, the value is used necessarily.

    Default:
    GexMinimalGroupSize=0

# Log Level

The log level can be specified that TTSSH records to TTSSH.LOG file.

    LogLevel=<Value>

Value | Action
--- | ---
0 | Invalid
5 | FATAL
10 | ERROR
30 | WARNING
50 | NOTICE
80 | INFO
100 | VERBOSE
200 | SSHDUMP

    Default:
    LogLevel=0

# Sign algorithm order of RSA publickey authentication

When publickey authentication with RSA key, some hash algorithms are available for generate sign.
You can configure the priority of sign algorithm.
Among the sign algorithms supported by server and client, highest priority algorithm in client is used.

Below setting takes priority rsa-sha2-256 lather than rsa-sha2-512.

    RSAPubkeySignAlgorithmOrder=2310

value | sign algorithm | hash algorithm for generate sign
--- | --- | ---
3 | rsa-sha2-512 | SHA-512
2 | rsa-sha2-256 | SHA-256
1 | ssh-rsa | SHA1
0 | below this line are disabled.

Note:
This config is for the priority of publickey authentication sign algorithm. Not for the priority of server hostkey sign algorithm.
Also this config is for publickey authentication sign algorithm with RSA key. Not for other type keys.

    Default:
    RSAPubkeySignAlgorithmOrder=3210

# Destination display for X11 transfer

When destination display for X11 transfer is specified, please change the X11Display entry of [TTSSH] section in the following.

    X11Display=<Display specification>

The display specification can be used as X11 normal format([<host>]:[<display number>[.<screen number>]). When the X11Display is not any specified _empty string_, the DISPLAY environment variable is enabled and the value is used. The environment variable is disable and the localhost:0.0 is used.

This configuration is overwitten with /ssh-X command line option. The configuration priority is as follows.

1. /ssh-X command line option
2. X11Display entry of [TTSSH] section
3. DISPLAY environment variable
4. localhost:0.0

    Default:
    X11Display=