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mirror of https://git.tartarus.org/simon/putty.git synced 2025-01-10 01:48:00 +00:00
putty-source/test/testcrypt.py
Simon Tatham aaaf11d7fb testcrypt.py: use parameter names in diagnostics.
Making a virtue of the necessity of adding parameter names to
testcrypt.h a couple of commits ago, we can now use those names to
improve diagnostics, so that if you use the wrong type in a Python
function call the error message will tell you the name as well as the
index of the offending argument.

Also, the repr() text for the function itself will now print a full
prototype (albeit in a nasty hybrid of C, Python and testcrypt.h
syntax) which shows all the parameter names. That should be handy when
trying to remember the order of arguments at the REPL prompt.
2021-11-21 18:41:41 +00:00

424 lines
16 KiB
Python

import sys
import os
import numbers
import subprocess
import re
import string
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, argname, 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, argname, 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", "fptype", "httpdigesthash"}:
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, argname, to_preserve)]
for val in arg:
sublist.append(make_argword(val, ("val_mpint", False),
fnname, argindex, argname, 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, argname, 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 in {"pocklestatus", "mr_result"}:
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, retnames, argtypes, argnames):
self.fnname = fnname
self.rettypes = rettypes
self.retnames = retnames
self.argtypes = argtypes
self.argnames = argnames
def __repr__(self):
return "<Function {}({}) -> ({})>".format(
self.fnname,
", ".join(("consumed " if c else "")+t+" "+n
for (t,c),n in zip(self.argtypes, self.argnames)),
", ".join((t+" "+n if n is not None else t)
for t,n in zip(self.rettypes, self.retnames)),
)
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, self.argnames[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 _lex_testcrypt_header(header):
pat = re.compile(
# Skip any combination of whitespace and comments
'(?:{})*'.format('|'.join((
'[ \t\n]', # whitespace
'/\\*(?:.|\n)*?\\*/', # C90-style /* ... */ comment, ended eagerly
'//[^\n]*\n', # C99-style comment to end-of-line
))) +
# And then match a token
'({})'.format('|'.join((
# Punctuation
'\(',
'\)',
',',
# Identifier
'[A-Za-z_][A-Za-z0-9_]*',
# End of string
'$',
)))
)
pos = 0
end = len(header)
while pos < end:
m = pat.match(header, pos)
assert m is not None, (
"Failed to lex testcrypt.h at byte position {:d}".format(pos))
pos = m.end()
tok = m.group(1)
if len(tok) == 0:
assert pos == end, (
"Empty token should only be returned at end of string")
yield tok, m.start(1)
def _parse_testcrypt_header(tokens):
def is_id(tok):
return tok[0] in string.ascii_letters+"_"
def expect(what, why, eof_ok=False):
tok, pos = next(tokens)
if tok == '' and eof_ok:
return None
if hasattr(what, '__call__'):
description = lambda: ""
ok = what(tok)
elif isinstance(what, set):
description = lambda: " or ".join("'"+x+"' " for x in sorted(what))
ok = tok in what
else:
description = lambda: "'"+what+"' "
ok = tok == what
if not ok:
sys.exit("testcrypt.h:{:d}: expected {}{}".format(
pos, description(), why))
return tok
while True:
tok = expect({"FUNC", "FUNC_WRAPPED"},
"at start of function specification", eof_ok=True)
if tok is None:
break
expect("(", "after FUNC")
rettype = expect(is_id, "return type")
expect(",", "after return type")
funcname = expect(is_id, "function name")
expect(",", "after function name")
expect("(", "to begin argument list")
args = []
firstargkind = expect({"ARG", "VOID"}, "at start of argument list")
if firstargkind == "VOID":
expect(")", "after VOID")
else:
while True:
# Every time we come back to the top of this loop, we've
# just seen 'ARG'
expect("(", "after ARG")
argtype = expect(is_id, "argument type")
expect(",", "after argument type")
argname = expect(is_id, "argument name")
args.append((argtype, argname))
expect(")", "at end of ARG")
punct = expect({",", ")"}, "after argument")
if punct == ")":
break
expect("ARG", "to begin next argument")
expect(")", "at end of FUNC")
yield funcname, rettype, args
def _setup(scope):
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(os.path.join(putty_srcdir, "testcrypt.h")) as f:
header = f.read()
tokens = _lex_testcrypt_header(header)
for function, rettype, arglist in _parse_testcrypt_header(tokens):
rettypes = []
retnames = []
if rettype != "void":
rettypes.append(trim_argtype(rettype))
retnames.append(None)
argtypes = []
argnames = []
argsconsumed = []
for arg, argname in arglist:
if arg.startswith(outprefix):
rettypes.append(trim_argtype(arg[len(outprefix):]))
retnames.append(argname)
else:
consumed = False
if arg.startswith(consprefix):
arg = arg[len(consprefix):]
consumed = True
arg = trim_argtype(arg)
argtypes.append((arg, consumed))
argnames.append(argname)
func = Function(function, rettypes, retnames,
argtypes, argnames)
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