My awesome intercepting, load balancing and session management libraries for nginx+lua

I'm working on an awesome event-driven Lua proxy libraries for analyzing, intercepting, load balancing and session management.

source and doc address on github
https://github.com/yizhu2000/suproxy

It provides APIs for:

• Authentication intercept: Read or change credentials during authentication or introduce self-defined authenticator.
• Command Input Intercept: monitor, filter or change command input.
• Command Output Intercept: monitor, filter or change command reply.
• Context Collect: Get network, user, client and server information like IP, port, version etc.
• Session Manage: Store session in Redis, provide APIs for list, kill and search session.
• Protocol parser: Parse and encode protocol packets.
• Load Balance: Multi-upstream balancing with fault tolerance.

Here are some screenshort for：
Filter SQL for Oracle

Filter Command for linux/Unix

Log operation for SSH2

Log operation for SQL

Change welcome info for linux/Unix

Currently, supported protocols include SSH2, ORACLE TNS, SQLSERVER TDS, LDAP.

	SSH	SQL Server	Oracle	LDAP
Get Username	Y[^1]	Y[^2]	Y	Y[^6]
Get Password	Y[^1]	Y[^2]	N	Y[^6]
Change Username	Y	Y	Y[^4]	Y
Change Password	Y	Y	N	Y
Third-Party Auth	Y	Y	Y[^5]	Y
Get Command	Y	Y	Y	Y[^7]
Get Reply	Y	Y	N	Y[^7]
Change Command	Y	Y[^3]	Y[^3]	N
Get Network Context (IP,port etc).	Y	Y	Y	Y
Get Client Context (client/server program name and version etc.)	Y	Y	Y	N

• [^1]: Password authentication only

• [^2]: Get username and password for SQL server disables SSL encryption

• [^3]: Change SQL command is not fully tested, some change like change select command to delete command may not success

• [^4]: Change Username for oracle10 is not supported

• [^5]: Only username based authentication supported

• [^6]: SSL not supported

• [^7]: Only search request and it's reply supported

SuProxy is written by pure Lua , and is designed under event-driven pattern, the use and extension of SuProxy libraries are simple: start a listener channel and handle it's event. This example shows how to start a SSH2 listener and handle authenticate success event of SSH connection.

server {
    listen 22;
    content_by_lua_block {
        local ssh=require("suproxy.ssh2"):new()
        local channel=require("suproxy.channel"):new({{ip="192.168.1.135",port=22}},tds)
        channel:run()
        ssh.AuthSuccessEvent:addHandler(ssh,logAuth)
    }
}

SuProxy provides basic load balancing ability. The example below shows how to pass multiple upstream to channel.

package.loaded.my_SSHB=package.loaded.my_SSHB or
require ("suproxy.balancer.balancer"):new{
    {ip="127.0.0.1",port=2222,id="local",gid="linuxServer"},
    {ip="192.168.46.128",port=22,id="remote",gid="linuxServer"},
    {ip="192.168.1.121",port=22,id="UBUNTU14",gid="testServer"}
}
local channel=require("suproxy.channel"):new(package.loaded.my_SSHB,ssh)

SuProxy can collect and maintain session context in memory or redis , below are the information collected by SuProxy in ssh connection.

{
    "sid": "xxxxxxxxxxxx",
    "uid": "xxxx",
    "stype": "ssh2",
    "uptime": 1600831353.066,
    "ctime": 1600831353.066,
    "ctx": {
        "srvIP": "127.0.0.1",
        "client": "SSH-2.0-PuTTY_Release_0.74",
        "clientIP": "127.0.0.1",
        "clientPort": "56127",
        "username": "xxxx",
        "srvPort": 2222,
        "server": "SSH-2.0-OpenSSH_8.2p1 Ubuntu-4ubuntu0.1"
    }
}