Provided by: proxytunnel_1.12.1-1build2_amd64 
NAME
proxytunnel - program to tunnel a connection through a standard HTTPS proxy
SYNOPSIS
proxytunnel [OPTION...] [host:port]
DESCRIPTION
proxytunnel is a program to tunnel any connection through a standard HTTPS proxy, circumventing standard
HTTP filtering mechanisms. It’s mostly used as a backend for OpenSSH’s ProxyCommand, and as a proxy
backend for Putty. It can also be used for other proxy-traversing purposes like proxy bouncing.
OPTIONS
-i, --inetd
Run from inetd (default: off).
-a, --standalone=[address:]port
Run as standalone daemon on specified address and port. address may be a IPv4 address, a
bracket-enclosed IPv6 address or a bracket-enclosed combination of IPv6 address, '%' and interface
name. The latter format is only required with link-local IPv6 addresses. The daemon listens on any
address if address is not given.
Examples
22, 123.45.67.89:22, [2001:db8::123:4567:89ab:cdef]:22, [2001:db8::123:4567:89ab:cdef%eth0]:22
-p, --proxy=host:port
Use host and port as the local proxy to connect to, if not specified the HTTP_PROXY environment
variable, if set, will be used instead.
-r, --remproxy=host:port
Use host and port as the remote (secondary) proxy to connect to.
-d, --dest=host:port
Use host and port as the destination for the tunnel, you can also specify them as the argument to the
proxytunnel command.
-e, --encrypt
SSL encrypt data between local proxy and destination.
-E, --encrypt-proxy
SSL encrypt data between client and local proxy.
-X, --encrypt-remproxy
SSL encrypt data between local and remote (secondary) proxy.
ADDITIONAL OPTIONS
-W, --wa-bug-29744
Workaround ASF Bugzilla 29744: If SSL is in use (by -e, -E, -X options), stop using it immediately
after the CONNECT exchange to workaround apache server bugs (This might not work on all setups).
-B, --buggy-encrypt-proxy
Equivalent to -E -W (Provided for backwards compatibility).
-z, --no-check-certificate
Do not verify server SSL certificate when establishing an SSL connection. By default, the server SSL
certificate is verified and the target host name is checked against the server certificate’s subject
alternative names if any are present, or common name if there are no subject alternative names.
-C, --cacert=filename/directory
Specify a CA certificate file (or directory containing CA certificate(s)) to trust when verifying a
server SSL certificate. If a directory is provided, it must be prepared with OpenSSL’s c_rehash tool
(default, unless changed at compile time using DEFAULT_CA_FILE or DEFAULT_CA_DIR options:
/etc/ssl/certs).
-4, --ipv4
Enforce the use of IPv4 when connecting to the local proxy.
-6, --ipv6
Enforce the use of IPv6 when connecting to the local proxy.
-F, --passfile=filename
Use filename for reading username and password for HTTPS proxy authentication, the file uses the same
format as .wgetrc and can be shared with wget. Use this option, or environment variables to hide the
password from other users.
-P, --proxyauth=username:password
Use username and password as credentials to authenticate against a local HTTPS proxy, the username
and password can also be specified in the PROXYUSER and PROXYPASS environment variables to hide them
from other users. If the password is omitted and no PROXYPASS environment variable is set,
proxytunnel will prompt for a password.
-R, --remproxyauth=username:password
Use username and password as credentials to authenticate against a remote (secondary) HTTPS proxy,
the username and password can also be specified in the REMPROXYUSER and REMPROXYPASS environment
variables to hide them from other users. If the password is omitted and no REMPROXYPASS environment
variable is set, proxytunnel will prompt for a password.
-c, --cert=filename
Provide the name of the file containing the SSL client certificate to authenticate by client
certificate against local proxy, remote proxy or destination. The file must be in PEM format. On top
of this it may contain one or more intermediary certificates missing at the servers’s end,
effectively forming a certificate chain. Requires specification of -k, --key in addition. Ignored if
neither -e, --encrypt nor -E, --encrypt-proxy nor -X, --encrypt-remproxy is given.
-k, --key=filename
Provide the name of the file containing the SSL client key to authenticate by client certificate
against local proxy, remote proxy or destination. The file must be in PEM format. Requires
specification of -c, --cert in addition. Ignored if neither -e, --encrypt nor -E, --encrypt-proxy nor
-X, --encrypt-remproxy is given.
-N, --ntlm
Use NTLM based authentication.
-t, --domain=STRING
Specify NTLM domain (default: autodetect).
-H, --header=STRING
Add additional HTTP headers to send to proxy.
-o, --host=host[:port]
Send a custom Host header. With SSL connections host is also sent as SNI.
-x, --proctitle=STRING
Use a different process title.
MISCELLANEOUS OPTIONS
-v, --verbose
Turn on verbosity.
-q, --quiet
Suppress messages.
-h, --help
Print help and exit.
-V, --version
Print version and exit.
ARGUMENTS
host:port is the destination hostname and port number combination.
Note
Specifying the destination as arguments is exactly the same as specifying them using the -d or --dest
option.
USAGE
Depending on your situation you might want to do any of the following things:
• Connect through a local proxy to your home system on port 22
$ proxytunnel -v -p proxy.company.com:8080 -d system.home.nl:22
• Connect through a local proxy (with authentication) to your home system
$ proxytunnel -v -p proxy.company.com:8080 -P username:password -d system.home.nl:22
• Connect through a local proxy (with authentication) hiding your password
$ export PROXYPASS=password
$ proxytunnel -v -p proxy.company.com:8080 -P username -d system.home.nl:22
• Connect through a local proxy to a remote proxy and bounce to any system
$ proxytunnel -v -p proxy.company.com:8080 -r proxy.athome.nl:443 -d system.friend.nl:22
• Connect using SSL through a local proxy to your home system
$ proxytunnel -v -E -p proxy.company.com:8080 -d system.home.nl:22
OPENSSH CONFIGURATION
To use this program with OpenSSH to connect to a host somewhere, create a ~/.ssh/config file with the
following content:
Host system.athome.nl
ProxyCommand proxytunnel -p proxy.company.com:8080 -d %h:%p
ServerAliveInterval 30
Note
The ServerAliveInterval directive makes sure that idle connections are not being dropped by
intermediate firewalls that remove active sessions aggressively. If you see your connection dropping
out, try to lower the value even more.
To use the dynamic (SOCKS) portforwarding capability of the SSH client, you can specify the
DynamicForward directive in your ssh_config file like:
Host system.athome.nl
DynamicForward 1080
ProxyCommand proxytunnel -p proxy.company.com:8080 -d %h:%p
ServerAliveInterval 30
NOTES
Important
Most HTTPS proxies do not allow access to ports other than HTTPS (tcp/443) and SNEWS (tcp/563). In
this case you need to make sure the SSH daemon or remote proxy on the destination system is listening
on either tcp/443 or tcp/563 to get through.
ENVIRONMENT
Proxytunnel can be influenced by setting one of the following environment variables:
HTTP_PROXY
If this environment variable is set, proxytunnel will use it as the local proxy if -p or --proxy is
not provided.
PROXYUSER
If this environment variable is set, proxytunnel will use it as the username for proxy
authentication, unless specified using the -P or --proxyauth option.
PROXYPASS
If this environment variable is set, proxytunnel will use it as the password for proxy
authentication, unless specified using the -P or --proxyauth option.
REMPROXYUSER
If this environment variable is set, proxytunnel will use it as the username for remote (secondary)
proxy authentication, unless specified using the -R or --remproxyauth option.
REMPROXYPASS
If this environment variable is set, proxytunnel will use it as the password for remote (secondary)
proxy authentication, unless specified using the -R or --remproxyauth option.
SEE ALSO
ssh(1), ssh_config(8)
BUGS
This software is bug-free, at least we’d like to think so. If you do not agree with us, please provide
the proof with your friendly report at https://github.com/proxytunnel/proxytunnel/issues :)
AUTHOR
This manpage was initially written by Loïc Le Guyader <loic.leguyader@laposte.net[1]> for the Debian
GNU/Linux system, revamped in asciidoc by Dag Wieërs <dag@wieers.com[2]> and is now maintained by the
Proxytunnel developers.
Homepages at https://proxytunnel.sourceforge.io and https://github.com/proxytunnel/proxytunnel
NOTES
1. loic.leguyader@laposte.net
mailto:loic.leguyader@laposte.net
2. dag@wieers.com
mailto:dag@wieers.com
1.12.1 2024-02-06 PROXYTUNNEL(1)