Skip to content

Latest commit

 

History

History
254 lines (198 loc) · 6.76 KB

README.rst

File metadata and controls

254 lines (198 loc) · 6.76 KB
Raw

Usage

OpenSSH is a free version of the SSH connectivity tools that technical users of the Internet rely on. The passwords of Telnet, remote login (rlogin), and File Transfer Protocol (FTP) users are transmitted across the Internet unencrypted. OpenSSH encrypts all traffic, including passwords, to effectively eliminate eavesdropping, connection hijacking, and other attacks. Additionally, OpenSSH provides secure tunneling capabilities and several authentication methods, and supports all SSH protocol versions.

This file provides the sample pillars configurations for different use cases.

OpenSSH client

  • The OpenSSH client configuration with a shared private key:

    openssh:
  client:
    enabled: true
    use_dns: False
    user:
      root:
        enabled: true
        private_key:
          type: rsa
          key: ${_param:root_private_key}
        user: ${linux:system:user:root}

  • The OpenSSH client configuration with an individual private key and known host:

    openssh:
  client:
    enabled: true
    user:
      root:
        enabled: true
        user: ${linux:system:user:root}
        known_hosts:
        - name: repo.domain.com
          type: rsa
          fingerprint: dd:fa:e8:68:b1:ea:ea:a0:63:f1:5a:55:48:e1:7e:37
          fingerprint_hash_type: sha256|md5

  • The OpenSSH client configuration with keep alive settings:

    openssh:
  client:
    alive:
      interval: 600
      count: 3

OpenSSH server

  • The OpenSSH server simple configuration:

    openssh:
  server:
    enabled: true
    permit_root_login: true
    public_key_auth: true
    password_auth: true
    host_auth: true
    banner: Welcome to server!
    bind:
      address: 0.0.0.0
      port: 22

  • The OpenSSH server configuration with auth keys for users:

    openssh:
  server:
    enabled: true
    bind:
      address: 0.0.0.0
      port: 22
    ...
    user:
      newt:
        enabled: true
        user: ${linux:system:user:newt}
        public_keys:
        - ${public_keys:newt}
      root:
        enabled: true
        purge: true
        user: ${linux:system:user:root}
        public_keys:
        - ${public_keys:newt}

    Note

    Setting the purge parameter to true ensures that the exact authorized_keys contents will be filled explicitly from the model and undefined keys will be removed.

  • The OpenSSH server configuration that binds OpenSSH on multiple addresses and ports:

    openssh:
  server:
    enabled: true
    binds:
      - address: 127.0.0.1
        port: 22
      - address: 192.168.1.1
        port: 2222

  • The OpenSSH server with FreeIPA configuration:

    openssh:
  server:
    enabled: true
    bind:
      address: 0.0.0.0
      port: 22
    public_key_auth: true
    authorized_keys_command:
      command: /usr/bin/sss_ssh_authorizedkeys
      user: nobody

  • The OpenSSH server configuration with keep alive settings:

    openssh:
  server:
    alive:
      keep: yes
      interval: 600
      count: 3
#
# will give you an timeout of 30 minutes (600 sec x 3)

  • The OpenSSH server configuration with the DSA legacy keys enabled:

    openssh:
  server:
    dss_enabled: true

  • The OpenSSH server configuration with the duo 2FA

https://duo.com/docs/duounix with Match User 2FA can be bypassed for some accounts

openssh:
  server:
    use_dns: false
    password_auth: false
    challenge_response_auth: true
    ciphers:
      aes256-ctr:
        enabled: true
      aes192-ctr:
        enabled: true
      aes128-ctr:
        enabled: true
    authentication_methods:
      publickey:
        enabled: true
      keyboard-interactive:
        enabled: true
    match_user:
      jenkins:
        authentication_methods:
          publickey:
            enabled: true
  • OpenSSH server configuration supports AllowUsers, DenyUsers, AllowGroup,

DenyGroups via allow_users, deny_users, allow_groups, deny_groups keys respectively.

For example, here is how to manage AllowUsers configuration item:

openssh:
  server:
    allow_users:
      <user_name>:
        enabled: true
      <pattern_list_name>:
        enabled: true
        pattern: <pattern>

Elements of allow_users are either user names or pattern list names: * <user name> goes to configurational file as is. * <pattern list name> is not used directly - its main purpose is to provide a

meaningfull name for a pattern specified in 'pattern' key. Another advantage is that pattern can be overriden.

<enabled> by default is 'true'.

See PATTERNS in ssh_config(5) for more information on what <pattern> is.

CIS Compliance

There is a number of configuration options that make the OpenSSH service compliant with CIS Benchmark. These options can be found under metadata/service/server/cis, and are not enabled by default. For each CIS item a comprehensive description is provided with the pillar data.

See also https://www.cisecurity.org/cis-benchmarks/ for the details abouth CIS Benchmark.

Read more

Documentation and bugs