bincimap-up(1)

NAME
bincimap-up - IMAP server stub

SYNOPSIS
bincimap-up [options] -- <authenticator> bincimapd <maildepot> bincimap-up -- /var/qmail/bin/qmail-authuser bincimapd Maildir

DESCRIPTION
bincimap-up is a pre-authentication IMAP server typically invoked by sslserver providing encrypted IMAPS and IMAP/StartTLS connections; though tcpserver could be used for un-encrypted IMAP services as well. Since it includes only limited IMAP capabilities, it is a stub IMAP server only.

CONFIGURATION
bincimap-up uses the environment for reading its settings, typically given by envdir in the directory env as files with one line als content. Some environment variables can be overwritten with command line options. In the following samples, the environment variable (including possible settings) is shown left and their potential command line option is given right after the '|' symbol.

BINCIMAP_LOGIN=PLAIN+LOGIN
    includes the authentication methodes advertised. Its setting is mandatory. The default is PLAIN+LOGIN; though PLAIN+LOGIN+CRAM-MD5 is honored and the challenge is generated and deployed for verification. The method CRAM-MD5 requires access to the unencrypted passwords.

ALLOW_NONSSL_PLAINTEXT_LOGINS=yes | -a, --allow-plain
    If this setting is enabled, Binc IMAP will permit plain text authentication for unencrypted (SSL/TLS) IMAP sessions. This is considered unsafe unless the server is run on a private switched network. By default, plain text authentication is disabled for unencrypted sessions.

SHOW_VERSION_IN_GREETING=yes | -v, --show-version
    If this setting is enabled, Binc IMAP will expose its version string in the greeting presented to every connecting client. This is considered unsafe unless the server is run on a private switched network, because it eases the job of malicious users who exploit vulnerabilities in specific versions. By default, the version is not exposed in the server's greeting.

LOG_TYPE=[multilog|syslog] | -l[...], --log-type=[...]
    This setting toggles which method Binc IMAP should use for logging. syslog means to connect to syslog. multilog means to log to stderr(2) and typically used together with the multilog utility. For daemontools/supervise, use multilog. Default: multilog.

LOG_USER=LOG_MAIL
    is the syslog user name for loging. Default: LOG_DAEMON. Additionally, you can setup up to eight local tags for the syslog facility employing the environment variables LOG_LOCAL0 to LOG_LOCAL7.

DEPOT=[Maildir++|IMAPdir] | -d=[...], --depot=[...]
    This setting sets whether to use a Maildir++ or an IMAPdir depot. By default, the Maildir++ depot is used.

DELIMITER=<char> | -D<char>, --delimiter<char>
    This setting sets the mailbox hierarchy delimiter. By default, Binc IMAP uses '/' as the delimiter (i.e., a/b/c). When porting from servers that use a different delimiter, certain clients may protest if the delimiter changes. For example, Courier-IMAP uses '.' as its delimiter, and certain Mozilla/Thunderbird clients have problems dealing with a client using a different delimiter. Set this options to '.' to work around the problem.

--  Marks the end of options to bincimap-up. After this comes the checkpassword compatible authenticator. Note that it is essential that the authenticator invoked by bincimap-up does not clear the environment and sets the value for $USER correctly.

(trailing arguments)
    Binc IMAP's authenticator. The first argument is invoked as an authenticator subprocess of bincimap-up, with the rest of the arguments passed as the authenticator's local arguments.

ADDITIONAL ARGUMENTS
bincimap-up understands the following command line arguments upon call:

-h, -?, --help
    This option is passed to display basic usage on the command line.

--version
    The option is passed to show the version number of the server on the command line.

DIAGNOSTICS
bincimap-up and also bincimapd recognize the setting of the environment variable:

PROTOCOLDUMP=yes
    to record the IMAP session's commands under /tmp/bincimap-dump-<number>-<client-ip>-<random> for interrogating the command flow. Upon compile time, further informations can be invoked, which enable to diagnose bincimap's behaviour, which can be found in the adjacent documentation.

LOGGING
On connect bincimap-up records the PID and the IP addresss of the connecting client. On disconnect bincimap-up logs the PID and the IP addresss following the number of bytes read and written for this connection.

COPYRIGHT
Copyright (C) 2002-2005 Andreas Aardal Hanssen, 2023 Erwin Hoffmann This is free software; see the LICENSE for copying conditions. There is NO warranty.

SEE ALSO
multilog(8), supervise(8), tcpserver(1), sslserver(1), bincimap(1), bincimapd(1), qmail-authuser(8).