#!/usr/bin/ruby

# add-tor  -  Add a tor fingerprint line to the approved-routers file
#
# Tor's approved-routers file is expected to be versioned using RCS.
# This script checks for uncommitted changes, does a checkout of the
# file, adds the new fingerprint with a comment stating the server's
# operator, and commits the file to RCS again (using -u so that the
# working copy is not removed.
#
# Operator and fingerprint line are read from stdin.
#
# Before adding a fingerprint line, approved-routers is checked for
# rough syntactical correctness.  This script also checks that the
# nickname and fingerprint to be added do not already exist in the
# binding list.


# Copyright (c) 2006 by Peter Palfrader
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

BINDING = '/etc/tor/approved-routers'

def mysys(cmd)
	unless system(cmd)
		STDERR.puts "ERROR: #{cmd} failed"
		exit 1
	end
end

def check_nick(n)
	n =~ /^[a-zA-Z0-9]+$/
end

def check_fpr(fpr)
	fpr =~ /^([0-9A-F]{4} ){9}[0-9A-F]{4}$/
end

def parse_fprline(fprline)
	n = fprline[0 ... fprline.index(' ')]
	f = fprline[fprline.index(' ') + 1 .. -1 ]
	unless check_nick(n) and check_fpr(f)
		STDERR.puts "Invalid fpr syntax '#{fprline}'"
		exit 1
	end
	[n, f]
end



unless system("rcsdiff -q -u #{BINDING}")
	STDERR.puts "Uncommitted changes in #{BINDING}.  Aborting."
	exit 1
end

puts "Checking out #{BINDING}..."
mysys("co -l #{BINDING}")

print "Operator: "
@operator = readline.chop
unless @operator.index('@')
	STDERR.puts "ERROR: No @ found"
	exit 1
end

print "FPR Line: "
@fprline = readline.chop
(@nickname, @fpr) = parse_fprline(@fprline)

binding = File.new(BINDING,  "r+")
binding.readlines.each do |line|
	line.chop!
	next if line[0..0] == "#"
	(n,f) = parse_fprline(line)
	if (n == @nickname)
		STDERR.puts
		STDERR.puts "ERROR: Nickname #{n} already exists in #{BINDING} (fpr: #{f})"
		exit 1
	end
	if (f == @fpr)
		STDERR.puts
		STDERR.puts "ERROR: Fpr #{f} already exists in #{BINDING} (nickname: #{n})"
		exit 1
	end
end

puts
puts '| # ' + @operator
puts '| '   + @fprline
puts

binding.puts '# '+@operator
binding.puts @fprline
binding.close

puts "Committing #{BINDING}..."
mysys("ci -u -m'Add #{@nickname}' #{BINDING}")