ssh_scan：远程验证你 SSH 服务的配置和策略
SSH ssh_scan
`ssh_scan` 是一个面向 Linux 和 UNIX 服务器的易用的 SSH 服务参数配置和策略的扫描器程序，其思路来自[Mozilla OpenSSH 安全指南](https://wiki.mozilla.org/Security/Guidelines/OpenSSH)，这个指南为 SSH 服务参数配置提供了一个可靠的安全策略基线的建议，如加密算法（Ciphers），报文认证信息码算法（MAC），密钥交换算法（KexAlgos）和其它。


![](/data/attachment/album/201706/05/094154g4ah7ilcejlls4ii.jpg)


`ssh_scan` 有如下好处：


* 它的依赖是最小化的，`ssh_scan` 只引入了本地 Ruby 和 BinData 来进行它的工作，没有太多的依赖。
* 它是可移植的，你可以在其它的项目中使用 `ssh_scan` 或者将它用在[自动化任务](https://www.tecmint.com/automating-linux-system-administration-tasks/)上。
* 它是易于使用的，只需要简单的将它指向一个 SSH 服务就可以获得一个该服务所支持的选项和策略状态的 JSON 格式报告。
* 它同时也是易于配置的，你可以创建适合你策略需求的策略。


**建议阅读：** [如何在 Linux 上安装配置 OpenSSH 服务](https://www.tecmint.com/install-openssh-server-in-linux/)


### 如何在 Linux 上安装 ssh\_scan


有如下三种安装 `ssh_scan` 的方式：


使用 Ruby gem 来安装运行，如下：



```
----------- 在 Debian/Ubuntu ----------- 
$ sudo apt-get install rubygems
$ sudo gem install ssh_scan
----------- 在 CentOS/RHEL ----------- 
# yum install ruby rubygems
# gem install ssh_scan

```

使用[docker 容器](https://www.tecmint.com/install-docker-and-learn-containers-in-centos-rhel-7-6/)来运行，如下：



```
# docker pull mozilla/ssh_scan
# docker run -it mozilla/ssh_scan /app/bin/ssh_scan -t github.com

```

使用源码安装运行，如下：



```
# git clone https://github.com/mozilla/ssh_scan.git
# cd ssh_scan
# gpg2 --keyserver hkp://keys.gnupg.net --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3
# curl -sSL https://get.rvm.io | bash -s stable
# rvm install 2.3.1
# rvm use 2.3.1
# gem install bundler
# bundle install
# ./bin/ssh_scan

```

### 如何在 Linux 上使用 ssh\_scan


使用 `ssh_scan` 的语法如下：



```
$ ssh_scan -t ip地址
$ ssh_scan -t 主机名

```

举个例子来扫描 192.168.43.198 这台服务器的 SSH 配置和策略，键入：



```
$ ssh_scan -t 192.168.43.198

```

注意你同时也可以像下方展示的给 `-t` 选项传入一个[IP地址/地址段/主机名]：



```
$ ssh_scan -t 192.168.43.198,200,205
$ ssh_scan -t test.tecmint.lan

```

输出示例：



```
I, [2017-05-09T10:36:17.913644 #7145]  INFO -- : You're using the latest version of ssh_scan 0.0.19
[
  {
    "ssh_scan_version": "0.0.19",
    "ip": "192.168.43.198",
    "port": 22,
    "server_banner": "SSH-2.0-OpenSSH_7.2p2 Ubuntu-4ubuntu2.1",
    "ssh_version": 2.0,
    "os": "ubuntu",
    "os_cpe": "o:canonical:ubuntu:16.04",
    "ssh_lib": "openssh",
    "ssh_lib_cpe": "a:openssh:openssh:7.2p2",
    "cookie": "68b17bcca652eeaf153ed18877770a38",
    "key_algorithms": [
      "curve25519-sha256@libssh.org",
      "ecdh-sha2-nistp256",
      "ecdh-sha2-nistp384",
      "ecdh-sha2-nistp521",
      "diffie-hellman-group-exchange-sha256",
      "diffie-hellman-group14-sha1"
    ],
    "server_host_key_algorithms": [
      "ssh-rsa",
      "rsa-sha2-512",
      "rsa-sha2-256",
      "ecdsa-sha2-nistp256",
      "ssh-ed25519"
    ],
    "encryption_algorithms_client_to_server": [
      "chacha20-poly1305@openssh.com",
      "aes128-ctr",
      "aes192-ctr",
      "aes256-ctr",
      "aes128-gcm@openssh.com",
      "aes256-gcm@openssh.com"
    ],
    "encryption_algorithms_server_to_client": [
      "chacha20-poly1305@openssh.com",
      "aes128-ctr",
      "aes192-ctr",
      "aes256-ctr",
      "aes128-gcm@openssh.com",
      "aes256-gcm@openssh.com"
    ],
    "mac_algorithms_client_to_server": [
      "umac-64-etm@openssh.com",
      "umac-128-etm@openssh.com",
      "hmac-sha2-256-etm@openssh.com",
      "hmac-sha2-512-etm@openssh.com",
      "hmac-sha1-etm@openssh.com",
      "umac-64@openssh.com",
      "umac-128@openssh.com",
      "hmac-sha2-256",
      "hmac-sha2-512",
      "hmac-sha1"
    ],
    "mac_algorithms_server_to_client": [
      "umac-64-etm@openssh.com",
      "umac-128-etm@openssh.com",
      "hmac-sha2-256-etm@openssh.com",
      "hmac-sha2-512-etm@openssh.com",
      "hmac-sha1-etm@openssh.com",
      "umac-64@openssh.com",
      "umac-128@openssh.com",
      "hmac-sha2-256",
      "hmac-sha2-512",
      "hmac-sha1"
    ],
    "compression_algorithms_client_to_server": [
      "none",
      "zlib@openssh.com"
    ],
    "compression_algorithms_server_to_client": [
      "none",
      "zlib@openssh.com"
    ],
    "languages_client_to_server": [
    ],
    "languages_server_to_client": [
    ],
    "hostname": "tecmint",
    "auth_methods": [
      "publickey",
      "password"
    ],
    "fingerprints": {
      "rsa": {
        "known_bad": "false",
        "md5": "0e:d0:d7:11:f0:9b:f8:33:9c:ab:26:77:e5:66:9e:f4",
        "sha1": "fc:8d:d5:a1:bf:52:48:a6:7e:f9:a6:2f:af:ca:e2:f0:3a:9a:b7:fa",
        "sha256": "ff:00:b4:a4:40:05:19:27:7c:33:aa:db:a6:96:32:88:8e:bf:05:a1:81:c0:a4:a8:16:01:01:0b:20:37:81:11"
      }
    },
    "start_time": "2017-05-09 10:36:17 +0300",
    "end_time": "2017-05-09 10:36:18 +0300",
    "scan_duration_seconds": 0.221573169,
    "duplicate_host_key_ips": [
    ],
    "compliance": {
      "policy": "Mozilla Modern",
      "compliant": false,
      "recommendations": [
        "Remove these Key Exchange Algos: diffie-hellman-group14-sha1",
        "Remove these MAC Algos: umac-64-etm@openssh.com, hmac-sha1-etm@openssh.com, umac-64@openssh.com, hmac-sha1",
        "Remove these Authentication Methods: password"
      ],
      "references": [
        "https://wiki.mozilla.org/Security/Guidelines/OpenSSH"
      ]
    }
  }
]

```

你可以使用 `-p` 选项来指定不同的端口，`-L` 选项来开启日志记录配合 `-V` 选项来指定日志级别：



```
$ ssh_scan -t 192.168.43.198 -p 22222 -L ssh-scan.log -V INFO

```

另外，可以使用 `-P` 或 `--policy` 选项来指定一个策略文件（默认是 Mozilla Modern）（LCTT 译注：这里的 Modern 可能指的是 <https://wiki.mozilla.org/Security/Server_Side_TLS> 中提到的 Modern compatibility ）：



```
$ ssh_scan -t 192.168.43.198 -L ssh-scan.log -V INFO -P /path/to/custom/policy/file

```

ssh\_scan 使用帮助与其它示例：



```
$ ssh_scan -h

```

输出示例：



```
ssh_scan v0.0.17 (https://github.com/mozilla/ssh_scan)
Usage: ssh_scan [options]
-t, --target [IP/Range/Hostname] IP/Ranges/Hostname to scan
-f, --file [FilePath]            File Path of the file containing IP/Range/Hostnames to scan
-T, --timeout [seconds]          Timeout per connect after which ssh_scan gives up on the host
-L, --logger [Log File Path]     Enable logger
-O, --from_json [FilePath]       File to read JSON output from
-o, --output [FilePath]          File to write JSON output to
-p, --port [PORT]                Port (Default: 22)
-P, --policy [FILE]              Custom policy file (Default: Mozilla Modern)
--threads [NUMBER]           Number of worker threads (Default: 5)
--fingerprint-db [FILE]      File location of fingerprint database (Default: ./fingerprints.db)
--suppress-update-status     Do not check for updates
-u, --unit-test [FILE]           Throw appropriate exit codes based on compliance status
-V [STD_LOGGING_LEVEL],
--verbosity
-v, --version                    Display just version info
-h, --help                       Show this message
Examples:
ssh_scan -t 192.168.1.1
ssh_scan -t server.example.com
ssh_scan -t ::1
ssh_scan -t ::1 -T 5
ssh_scan -f hosts.txt
ssh_scan -o output.json
ssh_scan -O output.json -o rescan_output.json
ssh_scan -t 192.168.1.1 -p 22222
ssh_scan -t 192.168.1.1 -p 22222 -L output.log -V INFO
ssh_scan -t 192.168.1.1 -P custom_policy.yml
ssh_scan -t 192.168.1.1 --unit-test -P custom_policy.yml

```

SSH 服务器相关参考阅读：


1. [使用 SSH Keygen（ssh-keygen）五步实现 SSH 免密登录](https://www.tecmint.com/ssh-passwordless-login-using-ssh-keygen-in-5-easy-steps/)
2. [安全 SSH 服务器的 5 个最佳实践](/article-7683-1.html)
3. [使用 Chroot 来限制 SSH 用户进入某些目录](/article-8313-1.html)
4. [如何配置 SSH 连接来简化远程登录](/article-8306-1.html)


如果需要更详细的信息可以访问 `ssh_scan` 的 Github 仓库：<https://github.com/mozilla/ssh_scan>




---


作者简介：


Aaron Kili 是 Linux 与 F.O.S.S （自由及开源软件）爱好者，一位将来的 Linux 系统管理员，网站开发者，现在是一个热爱与计算机一起工作并且拥有强烈知识分信念的 TecMint 内容贡献者。




---


via: <https://www.tecmint.com/ssh_scan-ssh-configuration-and-policy-scanner-for-linux/>


作者：[Aaron Kili](https://www.tecmint.com/author/aaronkili/) 译者：[wcnnbdk1](https://github.com/wcnnbdk1) 校对：[wxy](https://github.com/wxy)


本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出


OK
**ssh_scan** is an easy-to-use prototype SSH configuration and policy scanner for Linux and UNIX servers, inspired by [Mozilla OpenSSH Security Guide](https://wiki.mozilla.org/Security/Guidelines/OpenSSH), which provides a reasonable baseline policy recommendation for SSH configuration parameters such as Ciphers, MACs, and KexAlgos and much more.

It has some of the following benefits:

- It has minimal dependencies, ssh_scan only employs native Ruby and BinData to do its work, no heavy dependencies.
- It’s portable, you can use ssh_scan in another project or for
[automation of tasks](https://www.tecmint.com/automating-linux-system-administration-tasks/). - It’s easy to use, simply point it at an SSH service and get a JSON report of what it supports and it’s policy status.
- It’s also configurable, you can create your own custom policies that fit your specific policy requirements.

**Suggested Read:** [How to Install and Configure OpenSSH Server in Linux](https://www.tecmint.com/install-openssh-server-in-linux/)

### How to Install ssh_scan in Linux

There are three ways you can install **ssh_scan** and they are:

To install and run as a gem, type:

----------- On Debian/Ubuntu -----------$ sudo apt-get install ruby gem $ sudo gem install ssh_scan----------- On CentOS/RHEL -----------# yum install ruby rubygem # gem install ssh_scan

To run from a [docker container](https://www.tecmint.com/install-docker-and-learn-containers-in-centos-rhel-7-6/), type:

# docker pull mozilla/ssh_scan # docker run -it mozilla/ssh_scan /app/bin/ssh_scan -t github.com

To install and run from source, type:

# git clone https://github.com/mozilla/ssh_scan.git # cd ssh_scan # gpg2 --keyserver hkp://keys.gnupg.net --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3 # curl -sSL https://get.rvm.io | bash -s stable # rvm install 2.3.1 # rvm use 2.3.1 # gem install bundler # bundle install # ./bin/ssh_scan

### How to Use ssh_scan in Linux

The syntax for using ssh_scan is as follows:

$ ssh_scan -t ip-address $ ssh_scan -t server-hostname

For example to scan SSH configs and policy of server **92.168.43.198**, enter:

$ ssh_scan -t 192.168.43.198

Note you can also pass a [IP/Range/Hostname] to the `-t`

option as shown in the options below:

$ ssh_scan -t 192.168.43.198,200,205 $ ssh_scan -t test.tecmint.lan

##### Sample Output

I, [2017-05-09T10:36:17.913644 #7145] INFO -- : You're using the latest version of ssh_scan 0.0.19 [ { "ssh_scan_version": "0.0.19", "ip": "192.168.43.198", "port": 22, "server_banner": "SSH-2.0-OpenSSH_7.2p2 Ubuntu-4ubuntu2.1", "ssh_version": 2.0, "os": "ubuntu", "os_cpe": "o:canonical:ubuntu:16.04", "ssh_lib": "openssh", "ssh_lib_cpe": "a:openssh:openssh:7.2p2", "cookie": "68b17bcca652eeaf153ed18877770a38", "key_algorithms": [ "[[email protected]]", "ecdh-sha2-nistp256", "ecdh-sha2-nistp384", "ecdh-sha2-nistp521", "diffie-hellman-group-exchange-sha256", "diffie-hellman-group14-sha1" ], "server_host_key_algorithms": [ "ssh-rsa", "rsa-sha2-512", "rsa-sha2-256", "ecdsa-sha2-nistp256", "ssh-ed25519" ], "encryption_algorithms_client_to_server": [ "[[email protected]]", "aes128-ctr", "aes192-ctr", "aes256-ctr", "[[email protected]]", "[[email protected]]" ], "encryption_algorithms_server_to_client": [ "[[email protected]]", "aes128-ctr", "aes192-ctr", "aes256-ctr", "[[email protected]]", "[[email protected]]" ], "mac_algorithms_client_to_server": [ "[[email protected]]", "[[email protected]]", "[[email protected]]", "[[email protected]]", "[[email protected]]", "[[email protected]]", "[[email protected]]", "hmac-sha2-256", "hmac-sha2-512", "hmac-sha1" ], "mac_algorithms_server_to_client": [ "[[email protected]]", "[[email protected]]", "[[email protected]]", "[[email protected]]", "[[email protected]]", "[[email protected]]", "[[email protected]]", "hmac-sha2-256", "hmac-sha2-512", "hmac-sha1" ], "compression_algorithms_client_to_server": [ "none", "[[email protected]]" ], "compression_algorithms_server_to_client": [ "none", "[[email protected]]" ], "languages_client_to_server": [ ], "languages_server_to_client": [ ], "hostname": "tecmint", "auth_methods": [ "publickey", "password" ], "fingerprints": { "rsa": { "known_bad": "false", "md5": "0e:d0:d7:11:f0:9b:f8:33:9c:ab:26:77:e5:66:9e:f4", "sha1": "fc:8d:d5:a1:bf:52:48:a6:7e:f9:a6:2f:af:ca:e2:f0:3a:9a:b7:fa", "sha256": "ff:00:b4:a4:40:05:19:27:7c:33:aa:db:a6:96:32:88:8e:bf:05:a1:81:c0:a4:a8:16:01:01:0b:20:37:81:11" } }, "start_time": "2017-05-09 10:36:17 +0300", "end_time": "2017-05-09 10:36:18 +0300", "scan_duration_seconds": 0.221573169, "duplicate_host_key_ips": [ ], "compliance": { "policy": "Mozilla Modern", "compliant": false, "recommendations": [ "Remove these Key Exchange Algos: diffie-hellman-group14-sha1", "Remove these MAC Algos:[[email protected]],[[email protected]],[[email protected]], hmac-sha1", "Remove these Authentication Methods: password" ], "references": [ "https://wiki.mozilla.org/Security/Guidelines/OpenSSH" ] } } ]

You can use `-p`

to specify a different port, `-L`

to enable the logger and `-V`

to define the verbosity level as shown below:

$ ssh_scan -t 192.168.43.198 -p 22222 -L ssh-scan.log -V INFO

Additionally, use a custom policy file (default is Mozilla Modern) with the `-P`

or `--policy [FILE]`

like so:

$ ssh_scan -t 192.168.43.198 -L ssh-scan.log -V INFO -P /path/to/custom/policy/file

Type this to view all ssh_scan usage options and more examples:

$ ssh_scan -h

##### Sample Output

ssh_scan v0.0.17 (https://github.com/mozilla/ssh_scan) Usage: ssh_scan [options] -t, --target [IP/Range/Hostname] IP/Ranges/Hostname to scan -f, --file [FilePath] File Path of the file containing IP/Range/Hostnames to scan -T, --timeout [seconds] Timeout per connect after which ssh_scan gives up on the host -L, --logger [Log File Path] Enable logger -O, --from_json [FilePath] File to read JSON output from -o, --output [FilePath] File to write JSON output to -p, --port [PORT] Port (Default: 22) -P, --policy [FILE] Custom policy file (Default: Mozilla Modern) --threads [NUMBER] Number of worker threads (Default: 5) --fingerprint-db [FILE] File location of fingerprint database (Default: ./fingerprints.db) --suppress-update-status Do not check for updates -u, --unit-test [FILE] Throw appropriate exit codes based on compliance status -V [STD_LOGGING_LEVEL], --verbosity -v, --version Display just version info -h, --help Show this message Examples: ssh_scan -t 192.168.1.1 ssh_scan -t server.example.com ssh_scan -t ::1 ssh_scan -t ::1 -T 5 ssh_scan -f hosts.txt ssh_scan -o output.json ssh_scan -O output.json -o rescan_output.json ssh_scan -t 192.168.1.1 -p 22222 ssh_scan -t 192.168.1.1 -p 22222 -L output.log -V INFO ssh_scan -t 192.168.1.1 -P custom_policy.yml ssh_scan -t 192.168.1.1 --unit-test -P custom_policy.yml

Check out some useful artilces on SSH Server:

[SSH Passwordless Login Using SSH Keygen in 5 Easy Steps](https://www.tecmint.com/ssh-passwordless-login-using-ssh-keygen-in-5-easy-steps/)[5 Best Practices to Secure SSH Server](https://www.tecmint.com/5-best-practices-to-secure-and-protect-ssh-server/)[Restrict SSH User Access to Certain Directory Using Chrooted Jail](https://www.tecmint.com/restrict-ssh-user-to-directory-using-chrooted-jail/)[How to Configure Custom SSH Connections to Simplify Remote Access](https://www.tecmint.com/configure-custom-ssh-connection-in-linux/)

For more details visit ssh_scan Github repository: [https://github.com/mozilla/ssh_scan](https://github.com/mozilla/ssh_scan)

In this article, we showed you how to set up and use ssh_scan in Linux. Do you know of any similar tools out there? Let us know via the feedback form below, including any other thoughts concerning this guide.