class Net::SSH::KnownHosts
Searches an OpenSSH-style known-host file for a given host, and returns all matching keys. This is used to implement host-key verification, as well as to determine what key a user prefers to use for a given host.
This is used internally by Net::SSH, and will never need to be used directly by consumers of the library.
Constants
- SUPPORTED_TYPE
Attributes
The host-key file name that this KnownHosts instance will use to search for keys.
Public Class Methods
Instantiate a new KnownHosts instance that will search the given known-hosts file. The path is expanded file File.expand_path.
# File lib/net/ssh/known_hosts.rb, line 90 def initialize(source) @source = File.expand_path(source) end
Public Instance Methods
Looks in all user known host files (see #hostfiles) and tries to add an entry for the given host and key to the first file it is able to.
# File lib/net/ssh/known_hosts.rb, line 72 def add(host, key, options={}) hostfiles(options, :user).each do |file| begin KnownHosts.new(file).add(host, key) return rescue SystemCallError # try the next hostfile end end end
Looks in the given options
hash for the :user_known_hosts_file
and :global_known_hosts_file keys, and returns an array of all known hosts
files. If the :user_known_hosts_file key is not set, the default is
returned (~/.ssh/known_hosts and ~/.ssh/known_hosts2). If
:global_known_hosts_file is not set, the default is used
(/etc/ssh/ssh_known_hosts and /etc/ssh/ssh_known_hosts2).
If you only want the user known host files, you can pass :user as the second option.
# File lib/net/ssh/known_hosts.rb, line 55 def hostfiles(options, which=:all) files = [] if which == :all || which == :user files += Array(options[:user_known_hosts_file] || %w(~/.ssh/known_hosts ~/.ssh/known_hosts2)) end if which == :all || which == :global files += Array(options[:global_known_hosts_file] || %w(/etc/ssh/ssh_known_hosts /etc/ssh/ssh_known_hosts2)) end return files end
Returns an array of all keys that are known to be associatd with the given
host. The host
parameter is either the domain name or ip
address of the host, or both (comma-separated). Additionally, if a
non-standard port is being used, it may be specified by putting the host
(or ip, or both) in square brackets, and appending the port outside the
brackets after a colon. Possible formats for host
, then, are;
"net.ssh.test" "1.2.3.4" "net.ssh.test,1.2.3.4" "[net.ssh.test]:5555" "[1,2,3,4]:5555" "[net.ssh.test]:5555,[1.2.3.4]:5555
# File lib/net/ssh/known_hosts.rb, line 107 def keys_for(host) keys = [] return keys unless File.readable?(source) entries = host.split(/,/) File.open(source) do |file| scanner = StringScanner.new("") file.each_line do |line| scanner.string = line scanner.skip(/\s*/) next if scanner.match?(/$|#/) hostlist = scanner.scan(/\S+/).split(/,/) next unless entries.all? { |entry| hostlist.include?(entry) } scanner.skip(/\s*/) type = scanner.scan(/\S+/) next unless SUPPORTED_TYPE.include?(type) scanner.skip(/\s*/) blob = scanner.rest.unpack("m*").first keys << Net::SSH::Buffer.new(blob).read_key end end keys end
Searches all known host files (see #hostfiles) for all keys of the given host. Returns an array of keys found.
# File lib/net/ssh/known_hosts.rb, line 36 def search_for(host, options={}) search_in(hostfiles(options), host) end
Search for all known keys for the given host, in every file given in the
files
array. Returns the list of keys.
# File lib/net/ssh/known_hosts.rb, line 42 def search_in(files, host) files.map { |file| KnownHosts.new(file).keys_for(host) }.flatten end