An open source serveo/ngrok alternative.
Builds are made automatically on Google Cloud Build and Dockerhub. Feel free to either use the automated binaries or to build your own. If you submit a PR and would like access to Google Cloud Build's output (including pre-made PR binaries), feel free to let me know.
- Pull the Docker image
docker pull antoniomika/sish:latest
- Run the image
docker run -itd --name sish \ -v ~/sish/ssl:/ssl \ -v ~/sish/keys:/keys \ -v ~/sish/pubkeys:/pubkeys \ --net=host antoniomika/sish:latest \ -sish.addr=:22 \ -sish.https=:443 \ -sish.http=:80 \ -sish.httpsenabled=true \ -sish.httpspems=/ssl \ -sish.keysdir=/pubkeys \ -sish.pkloc=/keys/ssh_key \ -sish.bindrandom=false
- SSH to your host to communicate with sish
ssh -p 2222 -R 80:localhost:8080 ssi.sh
You can choose your own subdomain instead of relying on a randomly assigned one
by setting the
-sish.bindrandom option to
false and then selecting a
subdomain by prepending it to the remote port specifier:
ssh -p 2222 -R foo:80:localhost:8080 ssi.sh
If the selected subdomain is not taken, it will be assigned to your connection.
How it works
SSH can normally forward local and remote ports. This service implements an SSH server that only does that and nothing else. The service supports multiplexing connections over HTTP/HTTPS with WebSocket support. Just assign a remote port as port
80 to proxy HTTP traffic and
443 to proxy HTTPS traffic. If you use any other remote port, the server will listen to the port for connections, but only if that port is available.
If you want to use this service privately, it supports both public key and password authentication. To enable authentication, set
-sish.auth=true as one of your CLI options and be sure to configure
-sish.keysdir to your liking. The directory provided by
-sish.keysdir is watched for changes and will reload the authorized keys automatically. The authorized cert index is regenerated on directory modification, so removed public keys will also automatically be removed. Files in this directory can either be single key per file, or multiple keys per file separated by newlines, similar to
authorized_keys. Password auth can be disabled by setting
-sish.password="" as a CLI option.
One of my favorite ways of using this for authentication is like so:
sish@sish0:~/sish/pubkeys# curl https://github.com/antoniomika.keys > antoniomika
This will load my public keys from GitHub, place them in the directory that sish is watching, and then load the pubkey. As soon as this command is run, I can SSH normally and it will authorize me.
Whitelisting IP ranges or countries is also possible. Whole CIDR ranges can be
specified with the
-sish.whitelistedips option that accepts a comma-separated string like "22.214.171.124/22,126.96.36.199/22". If you want to whitelist a single
IP, use the
To whitelist countries, use
sish.whitelistedcountries with a comma-separated
string of countries in ISO format (for example, "pt" for Portugal). You'll also
need to set
There is a demo service (and my private instance) currently running on
ssi.sh that doesn't require any authentication. This service provides default logging (errors, connection IP/username, and pubkey fingerprint). I do not log any of the password authentication data or the data sent within the service/tunnels. My deploy uses the exact deploy steps that are listed above. This instance is for testing and educational purposes only. You can deploy this extremely easily on any host (Google Cloud Platform provides an always-free instance that this should run perfectly on). If the service begins to accrue a lot of traffic, I will enable authentication and then you can reach out to me to get your SSH key whitelisted (make sure it's on GitHub and you provide me with your GitHub username).
- This is by no means production ready in any way. This was hacked together and solves a fairly specific use case.
- You can help it get production ready by submitting PRs/reviewing code/writing tests/etc
- This is a fairly simple implementation, I've intentionally cut corners in some places to make it easier to write.
- If you have any questions or comments, feel free to reach out via email firstname.lastname@example.org or on freenode IRC #sish
sh-3.2# ./sish -h Usage of ./sish: -sish.addr string The address to listen for SSH connections (default "localhost:2222") -sish.auth Whether or not to require auth on the SSH service -sish.bannedcountries string A comma separated list of banned countries -sish.bannedips string A comma separated list of banned ips -sish.bannedsubdomains string A comma separated list of banned subdomains (default "localhost") -sish.bindrandom Bind ports randomly (OS chooses) (default true) -sish.bindrange string Ports that are allowed to be bound (default "0,1024-65535") -sish.cleanupunbound Whether or not to cleanup unbound (forwarded) SSH connections (default true) -sish.debug Whether or not to print debug information -sish.domain string The domain for HTTP(S) multiplexing (default "ssi.sh") -sish.forcerandomsubdomain Whether or not to force a random subdomain (default true) -sish.http string The address to listen for HTTP connections (default "localhost:80") -sish.https string The address to listen for HTTPS connections (default "localhost:443") -sish.httpsenabled Whether or not to listen for HTTPS connections -sish.httpspems string The location of pem files for HTTPS (fullchain.pem and privkey.pem) (default "ssl/") -sish.keysdir string Directory for public keys for pubkey auth (default "pubkeys/") -sish.password string Password to use for password auth (default "S3Cr3tP4$$W0rD") -sish.pkloc string SSH server private key (default "keys/ssh_key") -sish.pkpass string Passphrase to use for the server private key (default "S3Cr3tP4$$phrAsE") -sish.redirectroot Whether or not to redirect the root domain (default true) -sish.redirectrootlocation string Where to redirect the root domain to (default "https://github.com/antoniomika/sish") -sish.subdomainlen int The length of the random subdomain to generate (default 3) -sish.usegeodb Whether or not to use the maxmind geodb -sish.whitelistedcountries string A comma separated list of whitelisted countries -sish.whitelistedips string A comma separated list of whitelisted ips