openconnect man page

openconnect — Connect to Cisco AnyConnect VPN

Synopsis

openconnect [https://]server[:port][/group]

Description

The program openconnect connects to Cisco "AnyConnect" VPN servers, which use standard TLS and DTLS protocols for data transport.

The connection happens in two phases. First there is a simple HTTPS connection over which the user authenticates somehow - by using a certificate, or password or SecurID, etc. Having authenticated, the user is rewarded with an HTTP cookie which can be used to make the real VPN connection.

The second phase uses that cookie in an HTTPS CONNECT request, and data packets can be passed over the resulting connection. In auxiliary headers exchanged with the CONNECT request, a Session-ID and Master Secret for a DTLS connection are also exchanged, which allows data transport over UDP to occur.

Options

--config=CONFIGFILE

Read further options from CONFIGFILE before continuing to process options from the command line. The file should contain long-format options as would be accepted on the command line, but without the two leading -- dashes. Empty lines, or lines where the first non-space character is a # character, are ignored.

Any option except the config option may be specified in the file.

-b,--background
Continue in background after startup
--pid-file=PIDFILE
Save the pid to PIDFILE when backgrounding
-c,--certificate=CERT
Use SSL client certificate CERT which may be either a file name or, if OpenConnect has been built with an appropriate version of GnuTLS, a PKCS#11 URL.
-e,--cert-expire-warning=DAYS
Give a warning when SSL client certificate has DAYS left before expiry
-k,--sslkey=KEY
Use SSL private key KEY which may be either a file name or, if OpenConnect has been built with an appropriate version of GnuTLS, a PKCS#11 URL.
-C,--cookie=COOKIE
Use WebVPN cookie. COOKIE
--cookie-on-stdin
Read cookie from standard input.
-d,--deflate
Enable all compression, including stateful modes. By default, only stateless compression algorithms are enabled.
-D,--no-deflate
Disable all compression.
--compression=MODE

Set compression mode, where MODE is one of stateless , none , or all .

By default, only stateless compression algorithms which do not maintain state from one packet to the next (and which can be used on UDP transports) are enabled. By setting the mode to all stateful algorithms (currently only zlib deflate) can be enabled. Or all compression can be disabled by setting the mode to none .

--force-dpd=INTERVAL Use INTERVAL as minimum Dead Peer Detection interval for CSTP and DTLS, forcing use of DPD even when the server doesn't request it.

-g,--usergroup=GROUP
Use GROUP as login UserGroup
-h,--help
Display help text
--http-auth=METHODS
Use only the specified methods for HTTP authentication to a server. By default, only Negotiate, NTLM and Digest authentication are enabled. Basic authentication is also supported but because it is insecure it must be explicitly enabled. The argument is a comma-separated list of methods to be enabled. Note that the order does not matter: OpenConnect will use Negotiate, NTLM, Digest and Basic authentication in that order, if each is enabled, regardless of the order specified in the METHODS string.
-i,--interface=IFNAME
Use IFNAME for tunnel interface
-l,--syslog
Use syslog for progress messages
--timestamp
Prepend a timestamp to each progress message
-U,--setuid=USER
Drop privileges after connecting, to become user USER
--csd-user=USER
Drop privileges during CSD (Cisco Secure Desktop) script execution.
--csd-wrapper=SCRIPT
Run SCRIPT instead of the CSD (Cisco Secure Desktop) script.
-m,--mtu=MTU
Request MTU from server as the MTU of the tunnel.
--basemtu=MTU
Indicate MTU as the path MTU between client and server on the unencrypted network. Newer servers will automatically calculate the MTU to be used on the tunnel from this value.
-p,--key-password=PASS
Provide passphrase for certificate file, or SRK (System Root Key) PIN for TPM
-P,--proxy=PROXYURL
Use HTTP or SOCKS proxy for connection. A username and password can be provided in the given URL, and will be used for authentication. If authentication is required but no credentials are given, GSSAPI and automatic NTLM authentication using Samba's ntlm_auth helper tool may be attempted.
--proxy-auth=METHODS
Use only the specified methods for HTTP authentication to a proxy. By default, only Negotiate, NTLM and Digest authentication are enabled. Basic authentication is also supported but because it is insecure it must be explicitly enabled. The argument is a comma-separated list of methods to be enabled. Note that the order does not matter: OpenConnect will use Negotiate, NTLM, Digest and Basic authentication in that order, if each is enabled, regardless of the order specified in the METHODS string.
--no-proxy
Disable use of proxy
--libproxy
Use libproxy to configure proxy automatically (when built with libproxy support)
--key-password-from-fsid

Passphrase for certificate file is automatically generated from the fsid of the file system on which it is stored. The fsid is obtained from the statvfs(2) or statfs(2) system call, depending on the operating system. On a Linux or similar system with GNU coreutils, the fsid used by this option should be equal to the output of the command:

stat --file-system --printf=%i\\n $CERTIFICATE

It is not the same as the 128-bit UUID of the file system.

-q,--quiet
Less output
-Q,--queue-len=LEN
Set packet queue limit to LEN pkts
-s,--script=SCRIPT

Invoke SCRIPT to configure the network after connection. Without this, routing and name service are unlikely to work correctly. The script is expected to be compatible with the vpnc-script which is shipped with the "vpnc" VPN client. See http://www.infradead.org/openconnect/vp… for more information. This version of OpenConnect is configured to use /etc/vpnc/vpnc-script by default.

On Windows, a relative directory for the default script will be handled as starting from the directory that the openconnect executable is running from, rather than the current directory. The script will be invoked with the command-based script host cscript.exe.

-S,--script-tun
Pass traffic to 'script' program over a UNIX socket, instead of to a kernel tun/tap device. This allows the VPN IP traffic to be handled entirely in userspace, for example by a program which uses lwIP to provide SOCKS access into the VPN.
-u,--user=NAME
Set login username to NAME
-V,--version
Report version number
-v,--verbose
More output (may be specified multiple times for additional output)
-x,--xmlconfig=CONFIG
XML config file
--authgroup=GROUP
Choose authentication login selection
--authenticate

Authenticate only, and output the information needed to make the connection a form which can be used to set shell environment variables. When invoked with this option, openconnect will not make the connection, but if successful will output something like the following to stdout:

COOKIE=3311180634@13561856@1339425499@B315A0E29D16C6FD92EE...
HOST=10.0.0.1
FINGERPRINT=469bb424ec8835944d30bc77c77e8fc1d8e23a42

Thus, you can invoke openconnect as a non-privileged user (with access to the user's PKCS#11 tokens, etc.) for authentication, and then invoke openconnect separately to make the actual connection as root:

eval `openconnect --authenticate https://vpnserver.example.com`;
[ -n $COOKIE ] && echo $COOKIE |
  sudo openconnect --cookie-on-stdin $HOST --servercert $FINGERPRINT
--cookieonly
Fetch webvpn cookie only; don't connect
--printcookie
Print webvpn cookie before connecting
--cafile=FILE
Cert file for server verification
--disable-ipv6
Do not advertise IPv6 capability to server
--dtls-ciphers=LIST
Set OpenSSL ciphers to support for DTLS
--dtls-local-port=PORT
Use PORT as the local port for DTLS datagrams
--dump-http-traffic
Enable verbose output of all HTTP requests and the bodies of all responses received from the server.
--no-cert-check
Do not require server SSL certificate to be valid. Checks will still happen and failures will cause a warning message, but the connection will continue anyway. You should not need to use this option - if your servers have SSL certificates which are not signed by a trusted Certificate Authority, you can still add them (or your private CA) to a local file and use that file with the --cafile option.
--no-system-trust
Do not trust the system default certificate authorities. If this option is given, only certificate authorities given with the --cafile option, if any, will be trusted automatically.
--pfs

Enforces Perfect Forward Secrecy (PFS). That ensures that if the server's long-term key is compromised, any session keys established before the compromise will be unaffected. If this option is provided and the server does not support PFS in the TLS channel the connection will fail.

PFS is available in Cisco ASA releases 9.1(2) and higher; a suitable cipher suite may need to be manually enabled by the administrator using the ssl encryption setting.

--no-dtls
Disable DTLS
--no-http-keepalive

Version 8.2.2.5 of the Cisco ASA software has a bug where it will forget the client's SSL certificate when HTTP connections are being re-used for multiple requests. So far, this has only been seen on the initial connection, where the server gives an HTTP/1.0 redirect response with an explicit Connection: Keep-Alive directive. OpenConnect as of v2.22 has an unconditional workaround for this, which is never to obey that directive after an HTTP/1.0 response.

However, Cisco's support team has failed to give any competent response to the bug report and we don't know under what other circumstances their bug might manifest itself. So this option exists to disable ALL re-use of HTTP sessions and cause a new connection to be made for each request. If your server seems not to be recognising your certificate, try this option. If it makes a difference, please report this information to the openconnect-devel@lists.infradead.org mailing list.

--no-passwd
Never attempt password (or SecurID) authentication.
--no-xmlpost

Do not attempt to post an XML authentication/configuration request to the server; use the old style GET method which was used by older clients and servers instead.

This option is a temporary safety net, to work around potential compatibility issues with the code which falls back to the old method automatically. It causes OpenConnect to behave more like older versions (4.08 and below) did. If you find that you need to use this option, then you have found a bug in OpenConnect. Please see http://www.infradead.org/openconnect/ma… and report this to the developers.

--non-inter
Do not expect user input; exit if it is required.
--passwd-on-stdin
Read password from standard input
--protocol=PROTO
Select VPN protocol PROTO to be used for the connection. Supported protocols are anyconnect for Cisco AnyConnect (the default), and nc for experimental support for Juniper Network Connect (also supported by Junos Pulse servers).
--token-mode=MODE
Enable one-time password generation using the MODE algorithm. --token-mode=rsa will call libstoken to generate an RSA SecurID tokencode, --token-mode=totp will call liboath to generate an RFC 6238 time-based password, and --token-mode=hotp will call liboath to generate an RFC 4226 HMAC-based password. Yubikey tokens which generate OATH codes in hardware are supported with --token-mode=yubioath
--token-secret={ SECRET[,COUNTER] | @FILENAME }

The secret to use when generating one-time passwords/verification codes. Base 32-encoded TOTP/HOTP secrets can be used by specifying "base32:" at the beginning of the secret, and for HOTP secrets the token counter can be specified following a comma.

RSA SecurID secrets can be specified as an Android/iPhone URI or a raw numeric CTF string (with or without dashes).

For Yubikey OATH the token secret specifies the name of the credential to be used. If not provided, the first OATH credential found on the device will be used.

FILENAME, if specified, can contain any of the above strings. Or, it can contain a SecurID XML (SDTID) seed.

If this option is omitted, and --token-mode is "rsa", libstoken will try to use the software token seed saved in ~/.stokenrc by the "stoken import" command.

--reconnect-timeout
Keep reconnect attempts until so much seconds are elapsed. The default timeout is 300 seconds, which means that openconnect can recover VPN connection after a temporary network down time of 300 seconds.
--resolve=HOST:IP
Automatically resolve the hostname HOST to IP instead of using the normal resolver to look it up.
--servercert=SHA1
Accept server's SSL certificate only if its fingerprint matches SHA1.
--useragent=STRING
Use STRING as 'User-Agent:' field value in HTTP header. (e.g. --useragent 'Cisco AnyConnect VPN Agent for Windows 2.2.0133')
--local-hostname=STRING
Use STRING as 'X-CSTP-Hostname:' field value in HTTP header. For example --local-hostname 'mypc', will advertise the value 'mypc' as the suggested hostname to point to the provided IP address.
--os=STRING
OS type to report to gateway. Recognized values are: linux, linux-64, win, mac-intel, android, apple-ios. Reporting a different OS type may affect the dynamic access policy (DAP) applied to the VPN session. If the gateway requires CSD, it will also cause the corresponding CSD trojan binary to be downloaded, so you may need to use --csd-wrapper if this code is not executable on the local machine.

Signals

In the data phase of the connection, the following signals are handled:

SIGINT
performs a clean shutdown by logging the session off, disconnecting from the gateway, and running the vpnc-script to restore the network configuration.
SIGHUP
disconnects from the gateway and runs the vpnc-script, but does not log the session off; this allows for reconnection later using --cookie.
SIGUSR2
forces an immediate disconnection and reconnection; this can be used to quickly recover from LAN IP address changes.
SIGTERM
exits immediately without logging off or running vpnc-script.

Limitations

Note that although IPv6 has been tested on all platforms on which openconnect is known to run, it depends on a suitable vpnc-script to configure the network. The standard vpnc-script shipped with vpnc 0.5.3 is not capable of setting up IPv6 routes; the one from git://git.infradead.org/users/dwmw2/vpnc-scripts.git will be required.

Authors

David Woodhouse <dwmw2@infradead.org>

Referenced By

connman-vpn(8), connman-vpn-provider.config(5).