mmgen-autosign: batch offline transaction auto-signing

- once set up, requires no monitor or keyboard input; just insert USB stick,
  wait for signing to complete and remove
- LED status signaling on Raspberry Pi and Orange Pi

MANIFEST.in

@@ -8,5 +8,6 @@ include scripts/compute-file-chksum.py
 include scripts/deinstall.sh
 include scripts/tx-old2new.py
 include scripts/test-release.sh
+include scripts/mmgen-autosign
 
 prune test/ref/__db*

mmgen/globalvars.py

@@ -38,7 +38,7 @@ class g(object):
 		sys.exit(ev)
 	# Variables - these might be altered at runtime:
 
-	version      = '0.9.4a'
+	version      = '0.9.499'
 	release_date = 'October 2017'
 
 	proj_name = 'MMGen'

scripts/mmgen-autosign

@@ -0,0 +1,330 @@
+#!/usr/bin/env python
+#
+# mmgen = Multi-Mode GENerator, command-line Bitcoin cold storage solution
+# Copyright (C)2013-2017 Philemon <mmgen-py@yandex.com>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""
+mmgen-autosign: Auto-sign MMGen transactions
+"""
+
+import sys,os,subprocess,time,signal
+from stat import *
+
+from mmgen.common import *
+prog_name = os.path.basename(sys.argv[0])
+opts_data = lambda: {
+	'desc': 'Auto-sign MMGen transactions',
+	'usage':'[opts] [command]',
+	'options': """
+-h, --help           Print this help message
+--, --longhelp       Print help message for long options (common options)
+-l, --led            Use status LED to signal standby, busy and error
+-s, --stealth-led    Stealth LED mode - signal busy and error only, and only
+                     after successful authorization.
+""",
+	'notes': """
+
+
+                              COMMANDS
+
+gen_secret - generate the shared secret and copy to /dev/shm and USB stick
+wait       - start in loop mode: wait - mount - sign - unmount - wait
+
+
+                             USAGE NOTES
+
+If invoked with no command, the program mounts the USB stick, signs any
+unsigned transactions, unmounts the USB stick and exits.
+
+If invoked with 'wait', the program waits in a loop, mounting, signing
+and unmounting every time the USB stick is inserted.  The status LED
+indicates whether the program is busy or in standby mode, i.e. ready for
+USB stick insertion or removal.
+
+The USB stick must have a partition with the label MMGEN_TX and a user-
+writable directory '/tx', where unsigned MMGen transactions are placed.
+
+On the signing machine the directory /mnt/tx must exist and /etc/fstab must
+contain the following entry:
+
+    LABEL='MMGEN_TX' /mnt/tx auto noauto,user 0 0
+
+The signing wallet or wallets must be in MMGen mnemonic format and
+present in /dev/shm.  The wallet(s) can be created interactively with
+the following command:
+
+    $ mmgen-walletconv -i words -o words -d /dev/shm
+
+{} checks that a shared secret is present on the USB stick
+before signing transactions.  The shared secret is generated by invoking
+the command with 'gen_secret' with the USB stick inserted.  For good
+security, it's advisable to re-generate a new shared secret before each
+signing session.
+
+Status LED functionality is supported on Orange Pi and Raspberry Pi boards.
+
+This program is a helper script and is not installed by default.  You
+may copy it to your executable path if you wish, or just run it in place
+in the scripts directory of the MMGen repository root where it resides.
+""".format(prog_name)
+}
+
+cmd_args = opts.init(opts_data)
+if opt.stealth_led: opt.led = True
+
+mountpoint   = '/mnt/tx'
+tx_dir       = os.path.join(mountpoint,'tx')
+part_label   = 'MMGEN_TX'
+shm_dir      = '/dev/shm'
+secret_fn    = 'txsign-secret'
+tn_arg       = ([],['--testnet=1'])[bool(opt.testnet)]
+
+def check_daemon_running():
+	try: subprocess.check_output(['mmgen-tool'] + tn_arg + ['getbalance'])
+	except: die(1,'Daemon not running')
+
+def get_wallet_files():
+	wfs = [f for f in os.listdir(shm_dir) if f[-8:] == '.mmwords']
+	if not wfs:
+		die(1,'No mnemonic files present!')
+	return [os.path.join(shm_dir,w) for w in wfs]
+
+def get_secret_in_dir(d,on_fail='die'):
+	try:
+		with open(os.path.join(d,secret_fn)) as f:
+			return f.read().rstrip()
+	except:
+		msg('Unable to read secret file!')
+		if on_fail == 'die': sys.exit(1)
+		else:                return None
+
+def do_mount():
+	if not os.path.ismount(mountpoint):
+		msg('Mounting '+mountpoint)
+		subprocess.call(['mount',mountpoint])
+	try:
+		ds = os.stat(tx_dir)
+		assert S_ISDIR(ds.st_mode)
+		assert ds.st_mode & S_IWUSR|S_IRUSR == S_IWUSR|S_IRUSR
+	except:
+		die(1,'{} missing, or not read/writable by user!'.format(tx_dir))
+
+def do_umount():
+	if os.path.ismount(mountpoint):
+		subprocess.call(['sync'])
+		msg('Unmounting '+mountpoint)
+		subprocess.call(['umount',mountpoint])
+
+def sign():
+	dirlist  = os.listdir(tx_dir)
+	raw      = [f      for f in dirlist if f[-6:] == '.rawtx']
+	signed   = [f[:-6] for f in dirlist if f[-6:] == '.sigtx']
+	unsigned = [os.path.join(tx_dir,f) for f in raw if f[:-6] not in signed]
+
+	if unsigned:
+		cmd = ['mmgen-txsign','--yes','--outdir='+tx_dir] + tn_arg + unsigned + wfs
+		ret = subprocess.call(cmd)
+		msg('')
+		time.sleep(0.3)
+		return (1,0)[ret==0]
+	else:
+		msg('No unsigned transactions')
+		time.sleep(1)
+		return 0
+
+def wipe_existing_secret_files():
+	for d in (tx_dir,shm_dir):
+		fn = os.path.join(d,secret_fn)
+		try:
+			os.stat(fn)
+		except:
+			pass
+		else:
+			msg('\nWiping existing key {}'.format(fn))
+			subprocess.call(['wipe','-c',fn])
+
+def	create_secret_files():
+	from binascii import hexlify
+	secret = hexlify(os.urandom(16))
+	for d in (tx_dir,shm_dir):
+		fn = os.path.join(d,secret_fn)
+		desc = 'secret file in {}'.format(d)
+		msg('Creating ' + desc)
+		try:
+			with open(fn,'w') as f: f.write(secret+'\n')
+			os.chmod(fn,0400)
+			msg('Wrote ' + desc)
+		except:
+			die(2,'Unable to write ' + desc)
+
+def do_create_secret_files():
+	if not get_insert_status():
+		die(2,'USB stick not present!')
+	do_mount()
+	wipe_existing_secret_files()
+	create_secret_files()
+	do_umount()
+
+def ev_sleep(secs):
+	ev.wait(secs)
+	return (False,True)[ev.isSet()]
+
+def do_led(on,off):
+	if not on:
+		with open(status_ctl,'w') as f: f.write('0\n')
+		while True:
+			if ev_sleep(3600): return
+
+	while True:
+		with open(status_ctl,'w') as f: f.write('255\n')
+		if ev_sleep(on): return
+		with open(status_ctl,'w') as f: f.write('0\n')
+		if ev_sleep(off): return
+
+def set_led(cmd):
+	if not opt.led: return
+	timings = {
+		'off':     ( 0, 0 ),
+		'standby': ( 2.2, 0.2 ),
+		'busy':    ( 0.06, 0.06 ),
+		'error':   ( 0.5, 0.5 )}[cmd]
+	vmsg("Executing command '{}'".format(cmd))
+	global led_thread
+	if led_thread:
+		ev.set(); led_thread.join(); ev.clear()
+	led_thread = threading.Thread(target=do_led,name='LED loop',args=timings)
+	led_thread.start()
+
+def do_sign():
+	if not opt.stealth_led: set_led('busy')
+	do_mount()
+	ret = get_secret_in_dir(tx_dir,on_fail='return')
+	if ret == secret:
+		if opt.stealth_led: set_led('busy')
+		exit_val = sign()
+		do_umount()
+		set_led(('standby','off','error')[bool(exit_val)*2 or bool(opt.stealth_led)])
+	else:
+		if ret != None:
+			msg('Secret is incorrect!')
+		do_umount()
+		if not opt.stealth_led: set_led('error')
+
+def get_insert_status():
+	try: os.stat(os.path.join('/dev/disk/by-label/',part_label))
+	except: return False
+	else: return True
+
+def do_loop():
+	n,prev_status = 0,False
+	if not opt.stealth_led:
+		set_led('standby')
+	while True:
+		status = get_insert_status()
+		if status and not prev_status:
+			msg('Running command...')
+			do_sign()
+		prev_status = status
+		if not n % 10:
+			msg_r('\r{}\rwaiting'.format(' '*17))
+		time.sleep(1)
+		msg_r('.')
+		n += 1
+
+def check_access(fn,desc='status LED control',init_val=None):
+	try:
+		with open(fn) as f: b = f.read().strip()
+		with open(fn,'w') as f:
+			f.write('{}\n'.format(init_val or b))
+		return True
+	except:
+		m1 = "You do not have access to the {} file\n".format(desc)
+		m2 = "To allow access, run 'sudo chmod 0666 {}'".format(fn)
+		msg(m1+m2)
+		return False
+
+def check_wipe_present():
+	try:
+		subprocess.Popen(['wipe','-v'],stdout=subprocess.PIPE,stderr=subprocess.PIPE)
+	except:
+		die(2,"The 'wipe' utility must be installed before running this program")
+
+if opt.led:
+	import threading
+	status = {
+		'opi': '/sys/class/leds/orangepi:red:status/brightness',
+		'rpi': '/sys/class/leds/led0/brightness'
+	}
+	trigger = {
+		'rpi': '/sys/class/leds/led0/trigger', # mmc,none
+	}
+	for k in ('opi','rpi'):
+		try: os.stat(status[k])
+		except: pass
+		else:
+			board = k
+			status_ctl = status[board]
+			break
+	else:
+		die(2,'Control files not found!  LED option not supported')
+
+	if not check_access(status_ctl) or (
+		board == 'rpi' and not check_access(trigger[board],desc='LED trigger',init_val='none')):
+		sys.exit(1)
+
+	ev = threading.Event()
+	led_thread = None
+
+	if board == 'rpi':
+		with open(trigger[board],'w') as f: f.write('none\n')
+
+# main()
+if len(cmd_args) == 1 and cmd_args[0] == 'gen_secret':
+	do_create_secret_files()
+	sys.exit()
+
+check_wipe_present()
+wfs = get_wallet_files()
+secret = get_secret_in_dir(shm_dir,on_fail='die')
+check_daemon_running()
+
+def at_exit(nl=True):
+	if opt.led:
+		set_led('off')
+		ev.set()
+		led_thread.join()
+		if board == 'rpi':
+			with open(trigger[board],'w') as f: f.write('mmc0\n')
+	if nl: msg('')
+	raise SystemExit
+
+def handler(a,b): at_exit()
+
+signal.signal(signal.SIGTERM,handler)
+signal.signal(signal.SIGINT,handler)
+
+try:
+	if len(cmd_args) == 1 and cmd_args[0] == 'wait':
+		do_loop()
+	elif len(cmd_args) == 0:
+		do_sign()
+		at_exit(nl=False)
+	else:
+		msg('Invalid invocation')
+except IOError:
+	at_exit()
+except KeyboardInterrupt:
+	at_exit()

setup.py

@@ -83,7 +83,7 @@ module1 = Extension(
 	libraries    = ['secp256k1'],
 	library_dirs = ['/usr/local/lib',r'c:\msys\local\lib'],
 	# mingw32 needs this, Linux can use it, but it breaks mingw64
-	extra_link_args = (['-lgmp'],[])[have_mingw64 or have_arm],
+	extra_link_args = (['-lgmp'],[])[have_mingw64],
 	include_dirs = ['/usr/local/include',r'c:\msys\local\include'],
 	)