A fast TCP/UDP tunnel over HTTP
Chisel is a fast TCP/UDP tunnel, transported over HTTP, secured via SSH. Single executable including both client and server. Written in Go (golang). Chisel is mainly useful for passing through firewalls, though it can also be used to provide a secure endpoint into your network.
crypto/ssh)
ssh -o ProxyCommandproviding SSH over HTTP
Binaries
See the latest release or download and install it now with
curl https://i.jpillora.com/chisel! | bash
Docker
docker run --rm -it jpillora/chisel --help
Fedora
The package is maintained by the Fedora community. If you encounter issues related to the usage of the RPM, please use this issue tracker.
sudo dnf -y install chisel
Source
$ go get -v github.com/jpillora/chisel
A demo app on Heroku is running this
chisel server:
$ chisel server --port $PORT --proxy http://example.com # listens on $PORT, proxy web requests to http://example.com
This demo app is also running a simple file server on
:3000, which is normally inaccessible due to Heroku's firewall. However, if we tunnel in with:
$ chisel client https://chisel-demo.herokuapp.com 3000 # connects to chisel server at https://chisel-demo.herokuapp.com, # tunnels your localhost:3000 to the server's localhost:3000
and then visit localhost:3000, we should see a directory listing. Also, if we visit the demo app in the browser we should hit the server's default proxy and see a copy of example.com.
$ chisel --help Usage: chisel [command] [--help] Version: X.Y.Z Commands: server - runs chisel in server mode client - runs chisel in client mode Read more: https://github.com/jpillora/chisel
$ chisel server --help Usage: chisel server [options] Options: --host, Defines the HTTP listening host – the network interface (defaults the environment variable HOST and falls back to 0.0.0.0). --port, -p, Defines the HTTP listening port (defaults to the environment variable PORT and fallsback to port 8080). --key, An optional string to seed the generation of a ECDSA public and private key pair. All communications will be secured using this key pair. Share the subsequent fingerprint with clients to enable detection of man-in-the-middle attacks (defaults to the CHISEL_KEY environment variable, otherwise a new key is generate each run). --authfile, An optional path to a users.json file. This file should be an object with users defined like: { "": ["",""] } when connects, their will be verified and then each of the remote addresses will be compared against the list of address regular expressions for a match. Addresses will always come in the form ":" for normal remotes and "R::" for reverse port forwarding remotes. This file will be automatically reloaded on change. --auth, An optional string representing a single user with full access, in the form of . It is equivalent to creating an authfile with {"": [""]}. If unset, it will use the environment variable AUTH. --keepalive, An optional keepalive interval. Since the underlying transport is HTTP, in many instances we'll be traversing through proxies, often these proxies will close idle connections. You must specify a time with a unit, for example '5s' or '2m'. Defaults to '25s' (set to 0s to disable). --backend, Specifies another HTTP server to proxy requests to when chisel receives a normal HTTP request. Useful for hiding chisel in plain sight. --socks5, Allow clients to access the internal SOCKS5 proxy. See chisel client --help for more information. --reverse, Allow clients to specify reverse port forwarding remotes in addition to normal remotes. --tls-key, Enables TLS and provides optional path to a PEM-encoded TLS private key. When this flag is set, you must also set --tls-cert, and you cannot set --tls-domain. --tls-cert, Enables TLS and provides optional path to a PEM-encoded TLS certificate. When this flag is set, you must also set --tls-key, and you cannot set --tls-domain. --tls-domain, Enables TLS and automatically acquires a TLS key and certificate using LetsEncypt. Setting --tls-domain requires port 443. You may specify multiple --tls-domain flags to serve multiple domains. The resulting files are cached in the "$HOME/.cache/chisel" directory. You can modify this path by setting the CHISEL_LE_CACHE variable, or disable caching by setting this variable to "-". You can optionally provide a certificate notification email by setting CHISEL_LE_EMAIL. --tls-ca, a path to a PEM encoded CA certificate bundle or a directory holding multiple PEM encode CA certificate bundle files, which is used to validate client connections. The provided CA certificates will be used instead of the system roots. This is commonly used to implement mutual-TLS. --pid Generate pid file in current working directory -v, Enable verbose logging --help, This help text Signals: The chisel process is listening for: a SIGUSR2 to print process stats, and a SIGHUP to short-circuit the client reconnect timer Version: X.Y.Z Read more: https://github.com/jpillora/chisel
$ chisel client --help Usage: chisel client [options] [remote] [remote] ... is the URL to the chisel server. s are remote connections tunneled through the server, each of which come in the form: :::/ ■ local-host defaults to 0.0.0.0 (all interfaces). ■ local-port defaults to remote-port. ■ remote-port is required*. ■ remote-host defaults to 0.0.0.0 (server localhost). ■ protocol defaults to tcp. which shares : from the server to the client as :, or: R::::/ which does reverse port forwarding, sharing : from the client to the server's :. example remotes 3000 example.com:3000 3000:google.com:80 192.168.0.5:3000:google.com:80 socks 5000:socks R:2222:localhost:22 R:socks R:5000:socks stdio:example.com:22 1.1.1.1:53/udp When the chisel server has --socks5 enabled, remotes can specify "socks" in place of remote-host and remote-port. The default local host and port for a "socks" remote is 127.0.0.1:1080. Connections to this remote will terminate at the server's internal SOCKS5 proxy. When the chisel server has --reverse enabled, remotes can be prefixed with R to denote that they are reversed. That is, the server will listen and accept connections, and they will be proxied through the client which specified the remote. Reverse remotes specifying "R:socks" will listen on the server's default socks port (1080) and terminate the connection at the client's internal SOCKS5 proxy. When stdio is used as local-host, the tunnel will connect standard input/output of this program with the remote. This is useful when combined with ssh ProxyCommand. You can use ssh -o ProxyCommand='chisel client chiselserver stdio:%h:%p' \ [email protected] to connect to an SSH server through the tunnel. Options: --fingerprint, A *strongly recommended* fingerprint string to perform host-key validation against the server's public key. Fingerprint mismatches will close the connection. Fingerprints are generated by hashing the ECDSA public key using SHA256 and encoding the result in base64. Fingerprints must be 44 characters containing a trailing equals (=). --auth, An optional username and password (client authentication) in the form: ":". These credentials are compared to the credentials inside the server's --authfile. defaults to the AUTH environment variable. --keepalive, An optional keepalive interval. Since the underlying transport is HTTP, in many instances we'll be traversing through proxies, often these proxies will close idle connections. You must specify a time with a unit, for example '5s' or '2m'. Defaults to '25s' (set to 0s to disable). --max-retry-count, Maximum number of times to retry before exiting. Defaults to unlimited. --max-retry-interval, Maximum wait time before retrying after a disconnection. Defaults to 5 minutes. --proxy, An optional HTTP CONNECT or SOCKS5 proxy which will be used to reach the chisel server. Authentication can be specified inside the URL. For example, http://admin:[email protected]:8081 or: socks://admin:[email protected]my-server.com:1080 --header, Set a custom header in the form "HeaderName: HeaderContent". Can be used multiple times. (e.g --header "Foo: Bar" --header "Hello: World") --hostname, Optionally set the 'Host' header (defaults to the host found in the server url). --tls-ca, An optional root certificate bundle used to verify the chisel server. Only valid when connecting to the server with "https" or "wss". By default, the operating system CAs will be used. --tls-skip-verify, Skip server TLS certificate verification of chain and host name (if TLS is used for transport connections to server). If set, client accepts any TLS certificate presented by the server and any host name in that certificate. This only affects transport https (wss) connection. Chisel server's public key may be still verified (see --fingerprint) after inner connection is established. --tls-key, a path to a PEM encoded private key used for client authentication (mutual-TLS). --tls-cert, a path to a PEM encoded certificate matching the provided private key. The certificate must have client authentication enabled (mutual-TLS). --pid Generate pid file in current working directory -v, Enable verbose logging --help, This help text Signals: The chisel process is listening for: a SIGUSR2 to print process stats, and a SIGHUP to short-circuit the client reconnect timer Version: X.Y.Z Read more: https://github.com/jpillora/chisel
Encryption is always enabled. When you start up a chisel server, it will generate an in-memory ECDSA public/private key pair. The public key fingerprint (base64 encoded SHA256) will be displayed as the server starts. Instead of generating a random key, the server may optionally specify a key seed, using the
--keyoption, which will be used to seed the key generation. When clients connect, they will also display the server's public key fingerprint. The client can force a particular fingerprint using the
--fingerprintoption. See the
--helpabove for more information.
Using the
--authfileoption, the server may optionally provide a
user.jsonconfiguration file to create a list of accepted users. The client then authenticates using the
--authoption. See users.json for an example authentication configuration file. See the
--helpabove for more information.
Internally, this is done using the Password authentication method provided by SSH. Learn more about
crypto/sshhere http://blog.gopheracademy.com/go-and-ssh/.
docker run \ --name chisel -p 9312:9312 \ -d --restart always \ jpillora/chisel server -p 9312 --socks5 --key supersecret
chisel client --fingerprint 'rHb55mcxf6vSckL2AezFV09rLs7pfPpavVu++MF7AhQ=' :9312 socks
:1080
Since WebSockets support is required:
github.com/jpillora/chisel/sharecontains the shared package
github.com/jpillora/chisel/servercontains the server package
github.com/jpillora/chisel/clientcontains the client package
1.0- Initial release
1.1- Replaced simple symmetric encryption for ECDSA SSH
1.2- Added SOCKS5 (server) and HTTP CONNECT (client) support
1.3- Added reverse tunnelling support
1.4- Added arbitrary HTTP header support
1.5- Added reverse SOCKS support (by @aus)
1.6- Added client stdio support (by @BoleynSu)
1.7- Added UDP support