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require 'net/ssh/errors'
require 'net/ssh/known_hosts'
module Net
module SSH
module Verifiers
# Does a strict host verification, looking the server up in the known
# host files to see if a key has already been seen for this server. If this
# server does not appear in any host file, an exception will be raised
# (HostKeyUnknown). This is in contrast to the "Strict" class, which will
# silently add the key to your known_hosts file. If the server does appear at
# least once, but the key given does not match any known for the server, an
# exception will be raised (HostKeyMismatch).
# Otherwise, this returns true.
class Secure
def verify(arguments)
host_keys = arguments[:session].host_keys
# We've never seen this host before, so raise an exception.
process_cache_miss(host_keys, arguments, HostKeyUnknown, "is unknown") if host_keys.empty?
# If we found any matches, check to see that the key type and
# blob also match.
found = host_keys.any? do |key|
key.ssh_type == arguments[:key].ssh_type &&
key.to_blob == arguments[:key].to_blob
end
# If a match was found, return true. Otherwise, raise an exception
# indicating that the key was not recognized.
process_cache_miss(host_keys, arguments, HostKeyMismatch, "does not match") unless found
found
end
private
def process_cache_miss(host_keys, args, exc_class, message)
exception = exc_class.new("fingerprint #{args[:fingerprint]} " +
"#{message} for #{host_keys.host.inspect}")
exception.data = args
exception.callback = Proc.new do
host_keys.add_host_key(args[:key])
end
raise exception
end
end
end; end; end
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