sshpiper
is the reverse proxy for sshd. all protocols, including ssh, scp, port forwarding, running on top of ssh are supported.
Note: this is v1
version, checkout legacy v0
here
downstream
: the client side, typically an ssh client.upstream
: the server side, typically an ssh server.plugin
: handles the routing fromdownstream
toupstream
. Theplugin
is also responsible for mapping authentication methods to the upstream server. For example, the downstream may use password authentication, but the upstream server may receive public key authentication mapped bysshpiper
.additional challenge
: someplugins
will not only perform routing but also add additional challenges to SSH authentication for theupstream
server. For example, thedownstream
may be asked for two-factor authentication provided by theplugin
.
+---------+ +------------------+ +-----------------+
| | | | | |
| Bob +----ssh -l bob----+ | sshpiper +-------------> Bob' machine |
| | | | | | | |
+---------+ | | | | +-----------------+
+---> pipe-by-name--+ |
+---------+ | | | | +-----------------+
| | | | | | | |
| Alice +----ssh -l alice--+ | +-------------> Alice' machine |
| | | | | |
+---------+ +------------------+ +-----------------+
downstream sshpiper upstream
git clone https://github.com/tg123/sshpiper
cd sshpiper
git submodule update --init --recursive
mkdir out
go build -tags full -o out ./...
docker run -d -e USER_NAME=user -e USER_PASSWORD=pass -e PASSWORD_ACCESS=true -p 127.0.0.1:5522:2222 lscr.io/linuxserver/openssh-server
sudo ./out/sshpiperd ./out/fixed --target 127.0.0.1:5522
ssh 127.0.0.1 -l user -p 2222
Here illustrates the example of addional challenge
before the fixed
plugin.
sudo ./out/sshpiperd --log-level=trace ./out/simplemath -- ./out/fixed --target 127.0.0.1:5522
- ๐: routing plugin
- ๐: addtional challenge plugin
Plugin list
- workingdir ๐:
/home
-like directory to managed upstreams routing by sshpiped. - workingdirbykey ๐: same as
workingdir
but uses public key to route. - yaml ๐: config routing with a single yaml file.
- docker ๐: pipe into docker containers.
- kubernetes ๐: manage pipes via Kubernetes CRD.
- totp ๐: TOTP 2FA plugin. compatible with all RFC6238 authenticator, for example:
google authenticator
,azure authenticator
. - azdevicecode ๐: ask user to enter azure device code before login
- fixed ๐: fixed targeting the dummy sshd server
- simplemath ๐: ask for very simple math question before login, demo purpose
- githubapp ๐: login ssh with your github account
- restful by @11notes ๐๐: The rest plugin for sshpiperd is a simple plugin that allows you to use a restful backend for authentication and challenge.
- failtoban ๐: ban ip after failed login attempts
- openpubkey๐๐: integrate with openpubkey
sshpiperd
support recording the screen in typescript
format (not the lang). The format is compatible with scriptreplay(1)
To use it, start sshpiperd with --typescript-log-dir loggingdir
Example:
```
ssh [email protected] -p 2222
... do some commands
exit
$ cd loggingdir/user_name
$ ls *.timing *.typescript
1472847798.timing 1472847798.typescript
$ scriptreplay -t 1472847798.timing 1472847798.typescript # will replay the ssh session
```
During SSH publickey auth, RFC 4252 Section 7,
ssh client sign session_id
and some other data using private key into a signature sig
.
This is for server to verify that the connection is from the client not the man in the middle
.
However, sshpiper actually holds two ssh connection, and it is doing what the man in the middle
does.
the two ssh connections' session_id
will never be the same, because they are hash of the shared secret. RFC 4253 Section 7.2.
To support publickey auth, sshpiper
routing plugin must provide a new private key for the upstream
to sign the session_id
. This new private key is called mapping key
.
How this work
+------------+ +------------------------+
| | | |
| client | | sshpiper |
| PK_X +--------> | |
| | | v |
| | | Check Permission |
+------------+ | | |
| | |
| | | +----------------+
| v | | |
| sign agian | | server |
| using PK_Y +--------------> check PK_Y |
| | | |
| | | |
+------------------------+ +----------------+
- low level sshpiper api is fully redesigned to support more routing protocols.
- plugins system totally redesigned to be more flexible and extensible.
- plugins are now sperated from main process and no longer a single big binary, this allow user to write their own plugins without touching
sshpiperd
code.
- plugins are now sperated from main process and no longer a single big binary, this allow user to write their own plugins without touching
grpc
is first class now, the plugins are built on top of it
For plugins already in v1
, you need change params to new params. However, not all plugins are migrated to v1
yet, they are being migrated gradually. you can still use the old plugins in v0
branch
see CONTRIBUTING.md
MIT