Fake SSH Server

• 可用
• It Does Work

Why Write This

Make self happy.

How to download

Go to release page, and download the latest binary.

How to choose

The pre-built binary files are named with fakessh_{version}_{os}_{arch}[_minimal].

• darwin os means macOS.
• amd64 arch means x86_64, and it may have suffix like v2, v3. v3 means high performance but need CPU microarchitecture support, no suffix means v1 that can run on nearly all AMD/Intel x86_64 CPUs. See this wikipedia for more information.
• There is a binary named fakessh_{version}_macosuniversal that is a universal binary of macOS containing all architectures (amd64, arm64).
• Most of us should use the minimal binary. It contains basic features only, but also enough for most users. And some avanced features will be added in the future, may since version 0.5.0.

TODO

• configure file
• shell for git server (won't included in minimal build)
• max connections
• rate limit
• fake shell for log interders' actions (WIP in 0.5.1) (!minimal)
• custom root fs in tar/zip files (WIP in 0.5.2) (!minimal)

Configure File

Read this file for information.

CommandLine Usage

Usage of FakeSSH:
  -A    disable anti honeypot scan
  -V    show version of this binary
  -a    enable anti honeypot scan (default)
  -bind addr
        binding addr (default ":22")
  -c path
        config path
  -config path
        config path
  -delay int
        wait time for each login (ms)
  -devia int
        deviation for wait time (ms)
  -format [plain|json]
        log format: [plain|json] (default "plain")
  -gen
        generate a private key to key file path
  -h    show this page
  -help
        show this page
  -key path
        key file path, can set more than one
  -level [debug|info|warning]
        log level: [debug|info|warning] (default "info")
  -log file
        log file
  -max maxconn
        see maxconn
  -maxconn max:loss_ratio:hard_max
        max unauthenticated connections in format max:loss_ratio:hard_max, optionalable, see README
  -maxsucc maxsuccconn
        see maxsuccconn
  -maxsuccconn max:loss_rate:hard_max
        max success connections in format max:loss_rate:hard_max, see maxconn
  -mc maxconn
        see maxconn
  -msc maxsuccconn
        see maxsuccconn
  -o option
        see option
  -option module.key=value
        options for modules, "module.key=value"
  -passwd
        log password to file
  -r float
        success ratio float percent age (0.0 ~ 100.0, default: 0)
  -rate interval:limit
        rate limit in format interval:limit
  -seed string
        success seed (any string)
  -try int
        max try times (default 3)
  -type string
        type for generate private key (default "ed25519")
  -user user:password
        users in format user:password, can set more than one
  -version string
        ssh server version (default "OpenSSH_9.3p1")

key option

1. The general format is type:option, and the option part can leave blank.

2. Following types is available: ed25519, rsa, ecdsa, default is ed25519 if it's left empty.

3. If key path is not specialed, you can set multi types, separated with , . For example, rsa | rsa:2048 | ecdsa:P256,rsa | ed25519,ecdsa are all available, but only the first type set is used for generating mode.

4. Option for rsa is key size, default is 4096.

5. Option for ecdsa is curve type, such as P256, P384, P521, and default is P384.

max connections

You can use the commandline option -maxconn (or shorter -mc) to set the max connections for unauthenticated connections, the server.max_conn in configure file does it the same.

And -maxsuccconn (shorter -msc or server.max_succ_conn in configure file) to set the max success connections, with the same syntax.

The format of -maxconn and -maxsuccconn is max:loss_ratio:hard_max, and the format of configure file is shown in this file.

It means when the count of connections reaches max, the connection will loss in the ratio. The ratio will increase literally, and when connections equal or larger than hard_max it will reach 1.0.

• max is interger, optional means 0:
  • max < 0 => unlimited connections, unless hard_max.
  • max = 0 => use program default value(current is 100 for maxconn and 5 for maxsuccconn).
• loss_ratio is float, optional means 0:
  • loss_ratio < 0 => not loss connections until it reaches hard_max.
  • loss_ratio >= 0 => loss connections with the ratio, and it will increase literally until connections reaches hard_max.
• hard_max is interger, optional means 0:
  • hard_max <= 0 when max < 0 => unlimited connections.
  • hard_max <= 0 when max >= 0 => it will be the larger value of max * 2 and default value(current is 65535 for maxconn and 10 for maxsuccconn).