class Net::SSH::KnownHosts

by consumers of the library.
This is used internally by Net::SSH, and will never need to be used directly
to determine what key a user prefers to use for a given host.
matching keys. This is used to implement host-key verification, as well as
Searches an OpenSSH-style known-host file for a given host, and returns all

def add(host, key, options={})

to.
add an entry for the given host and key to the first file it is able
Looks in all user known host files (see KnownHosts.hostfiles) and tries to

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

def add(host, key)

instance), an exception will be raised.
and key. If it is unable to (because the file is not writable, for
Tries to append an entry to the current source file for the given host

def add(host, key)
  File.open(source, "a") do |file|
    blob = [Net::SSH::Buffer.from(:key, key).to_s].pack("m*").gsub(/\s/, "")
    file.puts "#{host} #{key.ssh_type} #{blob}"
  end
end

def hostfiles(options, which=:all)

the second option.
If you only want the user known host files, you can pass :user as

(/etc/ssh/ssh_known_hosts and /etc/ssh/ssh_known_hosts2).
:global_known_hosts_file is not set, the default is used
default is returned (~/.ssh/known_hosts and ~/.ssh/known_hosts2). If
hosts files. If the :user_known_hosts_file key is not set, the
:global_known_hosts_file keys, and returns an array of all known
Looks in the given +options+ hash for the :user_known_hosts_file and

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

def initialize(source)

file. The path is expanded file File.expand_path.
Instantiate a new KnownHosts instance that will search the given known-hosts

def initialize(source)
  @source = File.expand_path(source)
end

def keys_for(host)

"[net.ssh.test]:5555,[1.2.3.4]:5555
"[1,2,3,4]:5555"
"[net.ssh.test]:5555"
"net.ssh.test,1.2.3.4"
"1.2.3.4"
"net.ssh.test"

after a colon. Possible formats for +host+, then, are;
both) in square brackets, and appending the port outside the brackets
port is being used, it may be specified by putting the host (or ip, or
of the host, or both (comma-separated). Additionally, if a non-standard
given host. The +host+ parameter is either the domain name or ip address
Returns an array of all keys that are known to be associatd with the

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(/,/)
      found = entries.all? { |entry| hostlist.include?(entry) } ||
        known_host_hash?(hostlist, entries, scanner)
      next unless found
      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

def known_host_hash?(hostlist, entries, scanner)

stored as a HMAC-SHA1 hash in the known hosts.
Indicates whether one of the entries matches an hostname that has been

def known_host_hash?(hostlist, entries, scanner)
  if hostlist.size == 1 && hostlist.first =~ /\A\|1(\|.+){2}\z/
    chunks = hostlist.first.split(/\|/)
    salt = Base64.decode64(chunks[2])
    digest = OpenSSL::Digest.new('sha1')
    entries.each do |entry|
      hmac = OpenSSL::HMAC.digest(digest, salt, entry)
      return true if Base64.encode64(hmac).chomp == chunks[3]
    end
  end
  false
end

def search_for(host, options={})

of the given host. Returns an enumerable of keys found.
Searches all known host files (see KnownHosts.hostfiles) for all keys

def search_for(host, options={})
  HostKeys.new(search_in(hostfiles(options), host), host, self, options)
end

def search_in(files, host)

the +files+ array. Returns the list of keys.
Search for all known keys for the given host, in every file given in

def search_in(files, host)
  files.map { |file| KnownHosts.new(file).keys_for(host) }.flatten
end

Modules

Classes