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mirror of https://git.tartarus.org/simon/putty.git synced 2025-01-09 09:27:59 +00:00
putty-source/test/testcrypt.py
Simon Tatham 0faeb82ccd Add implementation of the Argon2 password hash.
This is going to be used in the new version of the PPK file format. It
was the winner of the Password Hashing Context, which I think makes it
a reasonable choice.

Argon2 comes in three flavours: one with no data dependency in its
memory addressing, one with _deliberate_ data dependency (intended to
serialise computation, to hinder parallel brute-forcing), and a hybrid
form that starts off data-independent and then switches over to the
dependent version once the sensitive input data has been adequately
mixed around. I test all three in the test suite; the side-channel
tester can only expect Argon2i to pass; and, following the spec's
recommendation, I'll be using Argon2id for the actual key file
encryption.
2021-02-20 16:51:29 +00:00

324 lines
12 KiB
Python

import sys
import os
import numbers
import subprocess
import re
import struct
from binascii import hexlify
assert sys.version_info[:2] >= (3,0), "This is Python 3 code"
# Expect to be run from the 'test' subdirectory, one level down from
# the main source
putty_srcdir = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
def coerce_to_bytes(arg):
return arg.encode("UTF-8") if isinstance(arg, str) else arg
class ChildProcessFailure(Exception):
pass
class ChildProcess(object):
def __init__(self):
self.sp = None
self.debug = None
self.exitstatus = None
self.exception = None
dbg = os.environ.get("PUTTY_TESTCRYPT_DEBUG")
if dbg is not None:
if dbg == "stderr":
self.debug = sys.stderr
else:
sys.stderr.write("Unknown value '{}' for PUTTY_TESTCRYPT_DEBUG"
" (try 'stderr'\n")
def start(self):
assert self.sp is None
override_command = os.environ.get("PUTTY_TESTCRYPT")
if override_command is None:
cmd = [os.path.join(putty_srcdir, "testcrypt")]
shell = False
else:
cmd = override_command
shell = True
self.sp = subprocess.Popen(
cmd, shell=shell, stdin=subprocess.PIPE, stdout=subprocess.PIPE)
def write_line(self, line):
if self.exception is not None:
# Re-raise our fatal-error exception, if it previously
# occurred in a context where it couldn't be propagated (a
# __del__ method).
raise self.exception
if self.debug is not None:
self.debug.write("send: {}\n".format(line))
self.sp.stdin.write(line + b"\n")
self.sp.stdin.flush()
def read_line(self):
line = self.sp.stdout.readline()
if len(line) == 0:
self.exception = ChildProcessFailure("received EOF from testcrypt")
raise self.exception
line = line.rstrip(b"\r\n")
if self.debug is not None:
self.debug.write("recv: {}\n".format(line))
return line
def already_terminated(self):
return self.sp is None and self.exitstatus is not None
def funcall(self, cmd, args):
if self.sp is None:
assert self.exitstatus is None
self.start()
self.write_line(coerce_to_bytes(cmd) + b" " + b" ".join(
coerce_to_bytes(arg) for arg in args))
argcount = int(self.read_line())
return [self.read_line() for arg in range(argcount)]
def wait_for_exit(self):
if self.sp is not None:
self.sp.stdin.close()
self.exitstatus = self.sp.wait()
self.sp = None
def check_return_status(self):
self.wait_for_exit()
if self.exitstatus is not None and self.exitstatus != 0:
raise ChildProcessFailure("testcrypt returned exit status {}"
.format(self.exitstatus))
childprocess = ChildProcess()
method_prefixes = {
'val_wpoint': 'ecc_weierstrass_',
'val_mpoint': 'ecc_montgomery_',
'val_epoint': 'ecc_edwards_',
'val_hash': 'ssh_hash_',
'val_mac': 'ssh2_mac_',
'val_key': 'ssh_key_',
'val_cipher': 'ssh_cipher_',
'val_dh': 'dh_',
'val_ecdh': 'ssh_ecdhkex_',
'val_rsakex': 'ssh_rsakex_',
'val_prng': 'prng_',
'val_pcs': 'pcs_',
'val_pockle': 'pockle_',
}
method_lists = {t: [] for t in method_prefixes}
class Value(object):
def __init__(self, typename, ident):
self._typename = typename
self._ident = ident
for methodname, function in method_lists.get(self._typename, []):
setattr(self, methodname,
(lambda f: lambda *args: f(self, *args))(function))
def _consumed(self):
self._ident = None
def __repr__(self):
return "Value({!r}, {!r})".format(self._typename, self._ident)
def __del__(self):
if self._ident is not None and not childprocess.already_terminated():
try:
childprocess.funcall("free", [self._ident])
except ChildProcessFailure:
# If we see this exception now, we can't do anything
# about it, because exceptions don't propagate out of
# __del__ methods. Squelch it to prevent the annoying
# runtime warning from Python, and the
# 'self.exception' mechanism in the ChildProcess class
# will raise it again at the next opportunity.
#
# (This covers both the case where testcrypt crashes
# _during_ one of these free operations, and the
# silencing of cascade failures when we try to send a
# "free" command to testcrypt after it had already
# crashed for some other reason.)
pass
def __long__(self):
if self._typename != "val_mpint":
raise TypeError("testcrypt values of types other than mpint"
" cannot be converted to integer")
hexval = childprocess.funcall("mp_dump", [self._ident])[0]
return 0 if len(hexval) == 0 else int(hexval, 16)
def __int__(self):
return int(self.__long__())
def marshal_string(val):
val = coerce_to_bytes(val)
assert isinstance(val, bytes), "Bad type for val_string input"
return "".join(
chr(b) if (0x20 <= b < 0x7F and b != 0x25)
else "%{:02x}".format(b)
for b in val)
def make_argword(arg, argtype, fnname, argindex, to_preserve):
typename, consumed = argtype
if typename.startswith("opt_"):
if arg is None:
return "NULL"
typename = typename[4:]
if typename == "val_string":
retwords = childprocess.funcall("newstring", [marshal_string(arg)])
arg = make_retvals([typename], retwords, unpack_strings=False)[0]
to_preserve.append(arg)
if typename == "val_mpint" and isinstance(arg, numbers.Integral):
retwords = childprocess.funcall("mp_literal", ["0x{:x}".format(arg)])
arg = make_retvals([typename], retwords)[0]
to_preserve.append(arg)
if isinstance(arg, Value):
if arg._typename != typename:
raise TypeError(
"{}() argument {:d} should be {} ({} given)".format(
fnname, argindex, typename, arg._typename))
ident = arg._ident
if consumed:
arg._consumed()
return ident
if typename == "uint" and isinstance(arg, numbers.Integral):
return "0x{:x}".format(arg)
if typename == "boolean":
return "true" if arg else "false"
if typename in {
"hashalg", "macalg", "keyalg", "cipheralg",
"dh_group", "ecdh_alg", "rsaorder", "primegenpolicy",
"argon2flavour"}:
arg = coerce_to_bytes(arg)
if isinstance(arg, bytes) and b" " not in arg:
return arg
if typename == "mpint_list":
sublist = [make_argword(len(arg), ("uint", False),
fnname, argindex, to_preserve)]
for val in arg:
sublist.append(make_argword(val, ("val_mpint", False),
fnname, argindex, to_preserve))
return b" ".join(coerce_to_bytes(sub) for sub in sublist)
raise TypeError(
"Can't convert {}() argument {:d} to {} (value was {!r})".format(
fnname, argindex, typename, arg))
def unpack_string(identifier):
retwords = childprocess.funcall("getstring", [identifier])
childprocess.funcall("free", [identifier])
return re.sub(b"%[0-9A-F][0-9A-F]",
lambda m: bytes([int(m.group(0)[1:], 16)]),
retwords[0])
def unpack_mp(identifier):
retwords = childprocess.funcall("mp_dump", [identifier])
childprocess.funcall("free", [identifier])
return int(retwords[0], 16)
def make_retval(rettype, word, unpack_strings):
if rettype.startswith("opt_"):
if word == b"NULL":
return None
rettype = rettype[4:]
if rettype == "val_string" and unpack_strings:
return unpack_string(word)
if rettype == "val_keycomponents":
kc = {}
retwords = childprocess.funcall("key_components_count", [word])
for i in range(int(retwords[0], 0)):
args = [word, "{:d}".format(i)]
retwords = childprocess.funcall("key_components_nth_name", args)
kc_key = unpack_string(retwords[0])
retwords = childprocess.funcall("key_components_nth_str", args)
if retwords[0] != b"NULL":
kc_value = unpack_string(retwords[0]).decode("ASCII")
else:
retwords = childprocess.funcall("key_components_nth_mp", args)
kc_value = unpack_mp(retwords[0])
kc[kc_key.decode("ASCII")] = kc_value
childprocess.funcall("free", [word])
return kc
if rettype.startswith("val_"):
return Value(rettype, word)
elif rettype == "int" or rettype == "uint":
return int(word, 0)
elif rettype == "boolean":
assert word == b"true" or word == b"false"
return word == b"true"
elif rettype == "pocklestatus":
return word.decode("ASCII")
raise TypeError("Can't deal with return value {!r} of type {!r}"
.format(word, rettype))
def make_retvals(rettypes, retwords, unpack_strings=True):
assert len(rettypes) == len(retwords) # FIXME: better exception
return [make_retval(rettype, word, unpack_strings)
for rettype, word in zip(rettypes, retwords)]
class Function(object):
def __init__(self, fnname, rettypes, argtypes):
self.fnname = fnname
self.rettypes = rettypes
self.argtypes = argtypes
def __repr__(self):
return "<Function {}>".format(self.fnname)
def __call__(self, *args):
if len(args) != len(self.argtypes):
raise TypeError(
"{}() takes exactly {} arguments ({} given)".format(
self.fnname, len(self.argtypes), len(args)))
to_preserve = []
retwords = childprocess.funcall(
self.fnname, [make_argword(args[i], self.argtypes[i],
self.fnname, i, to_preserve)
for i in range(len(args))])
retvals = make_retvals(self.rettypes, retwords)
if len(retvals) == 0:
return None
if len(retvals) == 1:
return retvals[0]
return tuple(retvals)
def _setup(scope):
header_file = os.path.join(putty_srcdir, "testcrypt.h")
linere = re.compile(r'^FUNC\d+\((.*)\)$')
valprefix = "val_"
outprefix = "out_"
optprefix = "opt_"
consprefix = "consumed_"
def trim_argtype(arg):
if arg.startswith(optprefix):
return optprefix + trim_argtype(arg[len(optprefix):])
if (arg.startswith(valprefix) and
"_" in arg[len(valprefix):]):
# Strip suffixes like val_string_asciz
arg = arg[:arg.index("_", len(valprefix))]
return arg
with open(header_file) as f:
for line in iter(f.readline, ""):
line = line.rstrip("\r\n").replace(" ", "")
m = linere.match(line)
if m is not None:
words = m.group(1).split(",")
function = words[1]
rettypes = []
argtypes = []
argsconsumed = []
if words[0] != "void":
rettypes.append(trim_argtype(words[0]))
for arg in words[2:]:
if arg.startswith(outprefix):
rettypes.append(trim_argtype(arg[len(outprefix):]))
else:
consumed = False
if arg.startswith(consprefix):
arg = arg[len(consprefix):]
consumed = True
arg = trim_argtype(arg)
argtypes.append((arg, consumed))
func = Function(function, rettypes, argtypes)
scope[function] = func
if len(argtypes) > 0:
t = argtypes[0][0]
if (t in method_prefixes and
function.startswith(method_prefixes[t])):
methodname = function[len(method_prefixes[t]):]
method_lists[t].append((methodname, func))
_setup(globals())
del _setup