The Net::SSH::Config class is used to parse OpenSSH configuration files, and translates that syntax into the configuration syntax that Net::SSH understands. This lets Net::SSH scripts read their configuration (to some extent) from OpenSSH configuration files (~/.ssh/config, /etc/ssh_config, and so forth).
Only a subset of OpenSSH configuration options are understood:
- Ciphers => maps to the :encryption option
- Compression => :compression
- CompressionLevel => :compression_level
- ConnectTimeout => maps to the :timeout option
- ForwardAgent => :forward_agent
- GlobalKnownHostsFile => :global_known_hosts_file
- HostBasedAuthentication => maps to the :auth_methods option
- HostKeyAlgorithms => maps to :host_key option
- HostKeyAlias => :host_key_alias
- HostName => :host_name
- IdentityFile => maps to the :keys option
- IdentitiesOnly => :keys_only
- Macs => maps to the :hmac option
- PasswordAuthentication => maps to the :auth_methods option
- Port => :port
- PreferredAuthentications => maps to the :auth_methods option
- ProxyCommand => maps to the :proxy option
- RekeyLimit => :rekey_limit
- User => :user
- UserKnownHostsFile => :user_known_hosts_file
Note that you will never need to use this class directly—you can control whether the OpenSSH configuration files are read by passing the :config option to Net::SSH.start. (They are, by default.)
Public class methods
Returns an array of locations of OpenSSH configuration files to parse by default.
# File lib/net/ssh/config.rb, line 41 41: def default_files 42: @@default_files 43: end
Loads the configuration data for the given host from all of the given files (defaulting to the list of files returned by default_files), translates the resulting hash into the options recognized by Net::SSH, and returns them.
# File lib/net/ssh/config.rb, line 49 49: def for(host, files=default_files) 50: translate(files.inject({}) { |settings, file| load(file, host, settings) }) 51: end
Load the OpenSSH configuration settings in the given file for the given host. If settings is given, the options are merged into that hash, with existing values taking precedence over newly parsed ones. Returns a hash containing the OpenSSH options. (See translate for how to convert the OpenSSH options into Net::SSH options.)
# File lib/net/ssh/config.rb, line 59 59: def load(path, host, settings={}) 60: file = File.expand_path(path) 61: return settings unless File.readable?(file) 62: 63: globals = {} 64: matched_host = nil 65: multi_host = [] 66: seen_host = false 67: IO.foreach(file) do |line| 68: next if line =~ /^\s*(?:#.*)?$/ 69: 70: if line =~ /^\s*(\S+)\s*=(.*)$/ 71: key, value = $1, $2 72: else 73: key, value = line.strip.split(/\s+/, 2) 74: end 75: 76: # silently ignore malformed entries 77: next if value.nil? 78: 79: key.downcase! 80: value = $1 if value =~ /^"(.*)"$/ 81: 82: value = case value.strip 83: when /^\d+$/ then value.to_i 84: when /^no$/i then false 85: when /^yes$/i then true 86: else value 87: end 88: 89: if key == 'host' 90: # Support "Host host1 host2 hostN". 91: # See http://github.com/net-ssh/net-ssh/issues#issue/6 92: multi_host = value.to_s.split(/\s+/) 93: matched_host = multi_host.select { |h| host =~ pattern2regex(h) }.first 94: seen_host = true 95: elsif !seen_host 96: if key == 'identityfile' 97: (globals[key] ||= []) << value 98: else 99: globals[key] = value unless settings.key?(key) 100: end 101: elsif !matched_host.nil? 102: if key == 'identityfile' 103: (settings[key] ||= []) << value 104: else 105: settings[key] = value unless settings.key?(key) 106: end 107: end 108: end 109: 110: settings = globals.merge(settings) if globals 111: 112: return settings 113: end
Given a hash of OpenSSH configuration options, converts them into a hash of Net::SSH options. Unrecognized options are ignored. The settings hash must have Strings for keys, all downcased, and the returned hash will have Symbols for keys.
# File lib/net/ssh/config.rb, line 119 119: def translate(settings) 120: settings.inject({}) do |hash, (key, value)| 121: case key 122: when 'ciphers' then 123: hash[:encryption] = value.split(/,/) 124: when 'compression' then 125: hash[:compression] = value 126: when 'compressionlevel' then 127: hash[:compression_level] = value 128: when 'connecttimeout' then 129: hash[:timeout] = value 130: when 'forwardagent' then 131: hash[:forward_agent] = value 132: when 'identitiesonly' then 133: hash[:keys_only] = value 134: when 'globalknownhostsfile' 135: hash[:global_known_hosts_file] = value 136: when 'hostbasedauthentication' then 137: if value 138: hash[:auth_methods] ||= [] 139: hash[:auth_methods] << "hostbased" 140: end 141: when 'hostkeyalgorithms' then 142: hash[:host_key] = value.split(/,/) 143: when 'hostkeyalias' then 144: hash[:host_key_alias] = value 145: when 'hostname' then 146: hash[:host_name] = value 147: when 'identityfile' then 148: hash[:keys] = value 149: when 'macs' then 150: hash[:hmac] = value.split(/,/) 151: when 'passwordauthentication' 152: if value 153: hash[:auth_methods] ||= [] 154: hash[:auth_methods] << "password" 155: end 156: when 'port' 157: hash[:port] = value 158: when 'preferredauthentications' 159: hash[:auth_methods] = value.split(/,/) 160: when 'proxycommand' 161: if value and !(value =~ /^none$/) 162: require 'net/ssh/proxy/command' 163: hash[:proxy] = Net::SSH::Proxy::Command.new(value) 164: end 165: when 'pubkeyauthentication' 166: if value 167: hash[:auth_methods] ||= [] 168: hash[:auth_methods] << "publickey" 169: end 170: when 'rekeylimit' 171: hash[:rekey_limit] = interpret_size(value) 172: when 'user' 173: hash[:user] = value 174: when 'userknownhostsfile' 175: hash[:user_known_hosts_file] = value 176: end 177: hash 178: end 179: end