mmgen-wallet/mmgen/passwdlist.py

#!/usr/bin/env python3
#
# MMGen Wallet, a terminal-based cryptocurrency wallet
# Copyright (C)2013-2025 The MMGen Project <mmgen@tuta.io>
#
# 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/>.

"""
passwdlist: Password list class for the MMGen suite
"""

from collections import namedtuple

from .util import ymsg, is_int, die
from .obj import ImmutableAttr, ListItemAttr, MMGenPWIDString, TwComment
from .key import PrivKey
from .addr import MMGenPasswordType, AddrIdx, AddrListID
from .addrlist import (
	AddrListChksum,
	AddrListIDStr,
	AddrListEntryBase,
	AddrList,
)

class PasswordListEntry(AddrListEntryBase):
	passwd  = ListItemAttr(str, typeconv=False) # TODO: create Password type
	idx     = ImmutableAttr(AddrIdx)
	comment = ListItemAttr(TwComment, reassign_ok=True)
	sec     = ListItemAttr(PrivKey, include_proto=True)

class PasswordList(AddrList):
	entry_type  = PasswordListEntry
	main_attr   = 'passwd'
	desc        = 'password'
	gen_desc    = 'password'
	gen_desc_pl = 's'
	gen_addrs   = False
	gen_keys    = False
	gen_passwds = True
	pw_len      = None
	dfl_pw_fmt  = 'b58'
	pwinfo      = namedtuple('passwd_info', ['min_len', 'max_len', 'dfl_len', 'valid_lens', 'desc', 'chk_func'])
	pw_info     = {
		# 32**25 < 2**128 < 32**26
		'b32':     pwinfo(10, 42 , 24, None,         'base32 password',           'baseconv.is_b32_str'),
		# 58**21 < 2**128 < 58**22
		'b58':     pwinfo(8,  36 , 20, None,         'base58 password',           'baseconv.is_b58_str'),
		'bip39':   pwinfo(12, 24 , 24, [12, 18, 24], 'BIP39 mnemonic',            'bip39.is_bip39_mnemonic'),
		'xmrseed': pwinfo(25, 25,  25, [25],         'Monero new-style mnemonic', 'xmrseed.is_xmrseed'),
		'hex':     pwinfo(32, 64 , 64, [32, 48, 64], 'hexadecimal password',      'util.is_hex_str')}
	chksum_rec_f = lambda foo, e: (str(e.idx), e.passwd)

	feature_warn_fs = 'WARNING: {!r} is a potentially dangerous feature.  Use at your own risk!'
	hex2bip39 = False

	def __init__(
			self,
			cfg,
			proto,
			*,
			infile          = None,
			seed            = None,
			pw_idxs         = None,
			pw_id_str       = None,
			pw_len          = None,
			pw_fmt          = None,
			chk_params_only = False,
			skip_chksum_msg = False):

		self.cfg = cfg
		self.proto = proto # proto is ignored

		if not cfg.debug_addrlist:
			self.dmsg_sc = self.noop

		if infile:
			self.infile = infile
			# sets self.pw_id_str, self.pw_fmt, self.pw_len, self.chk_func:
			self.data = self.file.parse_file(infile)
		else:
			if not chk_params_only:
				for k in (seed, pw_idxs):
					assert k
			self.pw_id_str = MMGenPWIDString(pw_id_str)
			self.set_pw_fmt(pw_fmt)
			self.set_pw_len(pw_len)
			if chk_params_only:
				return
			if self.hex2bip39:
				ymsg(self.feature_warn_fs.format(pw_fmt))
			self.set_pw_len_vs_seed_len(seed) # sets self.bip39, self.xmrseed, self.xmrproto self.baseconv
			self.al_id = AddrListID(sid=seed.sid, mmtype=MMGenPasswordType(self.proto, 'P'))
			self.data = self.generate(seed, pw_idxs)

		self.num_addrs = len(self.data)
		self.fmt_data = ''
		self.chksum = AddrListChksum(self)

		fs = f'{self.al_id.sid}-{self.pw_id_str}-{self.pw_fmt_disp}-{self.pw_len}[{{}}]'
		self.id_str = AddrListIDStr(self, fmt_str=fs)

		if not skip_chksum_msg:
			self.do_chksum_msg(record=not infile)

	def set_pw_fmt(self, pw_fmt):
		if pw_fmt == 'hex2bip39':
			self.hex2bip39 = True
			self.pw_fmt = 'bip39'
			self.pw_fmt_disp = 'hex2bip39'
		else:
			self.pw_fmt = pw_fmt
			self.pw_fmt_disp = pw_fmt
		if self.pw_fmt not in self.pw_info:
			die('InvalidPasswdFormat',
				f'{self.pw_fmt!r}: invalid password format.  Valid formats: {", ".join(self.pw_info)}')

	def chk_pw_len(self):
		assert self.pw_len, 'pw_len must be set'
		fs = '{l}: invalid user-requested length for {b} ({c}{m})'
		d = self.pw_info[self.pw_fmt]
		match self.pw_len:
			case pw_len if d.valid_lens and pw_len not in d.valid_lens:
				die(2, fs.format(l=pw_len, b=d.desc, c='not one of ', m=d.valid_lens))
			case pw_len if pw_len > d.max_len:
				die(2, fs.format(l=pw_len, b=d.desc, c='>', m=d.max_len))
			case pw_len if pw_len < d.min_len:
				die(2, fs.format(l=pw_len, b=d.desc, c='<', m=d.min_len))

	def set_pw_len(self, pw_len):
		d = self.pw_info[self.pw_fmt]

		if pw_len is None:
			self.pw_len = d.dfl_len
			return

		if not is_int(pw_len):
			die(2, f'{pw_len!r}: invalid user-requested password length (not an integer)')
		self.pw_len = int(pw_len)
		self.chk_pw_len()

	def set_pw_len_vs_seed_len(self, seed):

		match self.pw_fmt:
			case 'hex':
				pw_bytes = self.pw_len // 2
				good_pw_len = seed.byte_len * 2
			case 'bip39':
				from .bip39 import bip39
				self.bip39 = bip39()
				pw_bytes = bip39.nwords2seedlen(self.pw_len, in_bytes=True)
				good_pw_len = bip39.seedlen2nwords(seed.byte_len, in_bytes=True)
			case 'xmrseed':
				from .xmrseed import xmrseed
				from .protocol import init_proto
				self.xmrseed = xmrseed()
				self.xmrproto = init_proto(self.cfg, 'xmr')
				pw_bytes = xmrseed().seedlen_map_rev[self.pw_len]
				try:
					good_pw_len = xmrseed().seedlen_map[seed.byte_len]
				except:
					die(1, f'{seed.byte_len*8}: unsupported seed length for Monero new-style mnemonic')
			case 'b32' | 'b58' as pf:
				pw_int = (32 if pf == 'b32' else 58) ** self.pw_len
				pw_bytes = pw_int.bit_length() // 8
				from .baseconv import baseconv
				self.baseconv = baseconv(self.pw_fmt)
				good_pw_len = len(baseconv(pf).frombytes(b'\xff'*seed.byte_len))
			case pf:
				raise NotImplementedError(f'{pf!r}: unknown password format')

		match pw_bytes:
			case x if x > seed.byte_len:
				die(1,
					f'Cannot generate passwords with more entropy than underlying seed! ({len(seed.data)*8} bits)\n' +
					(f'Re-run the command with --passwd-len={good_pw_len}' if self.pw_fmt in ('bip39', 'hex') else
					'Re-run the command, specifying a password length of {} or less')
				)
			case x if x < seed.byte_len and self.pw_fmt in ('bip39', 'hex'):
				from .ui import keypress_confirm
				keypress_confirm(
					self.cfg,
					f'WARNING: requested {self.pw_info[self.pw_fmt].desc} length has less entropy ' +
					'than underlying seed!\nIs this what you want?',
					default_yes = True,
					do_exit = True)

	def gen_passwd(self, secbytes):
		match self.pw_fmt:
			case 'hex':
				return secbytes.hex()[:self.pw_len] # take most significant part
			case 'bip39':
				pw_len_bytes = self.bip39.nwords2seedlen(self.pw_len, in_bytes=True)
				return ' '.join(self.bip39.fromhex(secbytes[:pw_len_bytes].hex())) # take m.s.p.
			case 'xmrseed':
				pw_len_bytes = self.xmrseed.seedlen_map_rev[self.pw_len]
				bytes_preproc = self.xmrproto.preprocess_key(
					secbytes[:pw_len_bytes], # take most significant part
					None)
				return ' '.join(self.xmrseed.frombytes(bytes_preproc))
			case x if x in self.pw_info:
				return self.baseconv.frombytes(
					secbytes,
					pad = self.pw_len,
					tostr = True)[-self.pw_len:] # take least significant part
			case x:
				die(2, f'{x}: unrecognized password format')

	def check_format(self, pw):
		if not self.chk_func(pw):
			raise ValueError(f'Password is not valid {self.pw_info[self.pw_fmt].desc} data')
		pwlen = len(pw.split()) if self.pw_fmt in ('bip39', 'xmrseed') else len(pw)
		if pwlen != self.pw_len:
			raise ValueError(f'Password has incorrect length ({pwlen} != {self.pw_len})')
		return True

	def scramble_seed(self, seed):
		# Changing either pw_fmt or pw_len will cause a different, unrelated
		# set of passwords to be generated: this is what we want.
		# NB: In original implementation, pw_id_str was 'baseN', not 'bN'
		scramble_key = f'{self.pw_fmt}:{self.pw_len}:{self.pw_id_str}'

		if self.hex2bip39:
			pwlen = self.bip39.nwords2seedlen(self.pw_len, in_hex=True)
			scramble_key = f'hex:{pwlen}:{self.pw_id_str}'

		self.dmsg_sc('str', scramble_key)
		from .crypto import Crypto
		return Crypto(self.cfg).scramble_seed(seed, scramble_key.encode())