72 lines
2.1 KiB
Ruby
72 lines
2.1 KiB
Ruby
require 'net/ssh/errors'
|
|
require 'net/ssh/loggable'
|
|
require 'net/ssh/version'
|
|
|
|
module Net; module SSH; module Transport
|
|
|
|
# Negotiates the SSH protocol version and trades information about server
|
|
# and client. This is never used directly--it is always called by the
|
|
# transport layer as part of the initialization process of the transport
|
|
# layer.
|
|
#
|
|
# Note that this class also encapsulates the negotiated version, and acts as
|
|
# the authoritative reference for any queries regarding the version in effect.
|
|
class ServerVersion
|
|
include Loggable
|
|
|
|
# The SSH version string as reported by Net::SSH
|
|
PROTO_VERSION = "SSH-2.0-OpenSSH_5.0"
|
|
|
|
# Any header text sent by the server prior to sending the version.
|
|
attr_reader :header
|
|
|
|
# The version string reported by the server.
|
|
attr_reader :version
|
|
|
|
# Instantiates a new ServerVersion and immediately (and synchronously)
|
|
# negotiates the SSH protocol in effect, using the given socket.
|
|
def initialize(socket, logger)
|
|
@header = ""
|
|
@version = nil
|
|
@logger = logger
|
|
negotiate!(socket)
|
|
end
|
|
|
|
private
|
|
|
|
# Negotiates the SSH protocol to use, via the given socket. If the server
|
|
# reports an incompatible SSH version (e.g., SSH1), this will raise an
|
|
# exception.
|
|
def negotiate!(socket)
|
|
info { "negotiating protocol version" }
|
|
|
|
loop do
|
|
@version = ""
|
|
loop do
|
|
version_timeout = (9000/1000.0)+3 # (3 to 12 seconds)
|
|
b = socket.get_once(1,version_timeout)
|
|
if b.nil?
|
|
raise Net::SSH::Disconnect, "connection timed out or closed by remote host"
|
|
end
|
|
@version << b
|
|
break if b == "\n"
|
|
end
|
|
break if @version.match(/^SSH-/)
|
|
@header << @version
|
|
end
|
|
|
|
@version.chomp!
|
|
debug { "remote is `#{@version}'" }
|
|
|
|
unless @version.match(/^SSH-(1\.99|2\.0)-/)
|
|
raise Net::SSH::Exception, "incompatible SSH version `#{@version}'"
|
|
end
|
|
|
|
debug { "local is `#{PROTO_VERSION}'" }
|
|
socket.write "#{PROTO_VERSION}\r\n"
|
|
socket.flush
|
|
end
|
|
end
|
|
end; end; end
|
|
|