async def sign_authenticode_file(context, orig_path, fmt, *, authenticode_comment=None):
"""Sign a file in-place with authenticode, using autograph as a backend.
Args:
context (Context): the signing context
orig_path (str): the source file to sign
fmt (str): the format to sign with
comment (str): The authenticode comment to sign with, if present.
currently only used for msi files.
(Defaults to None)
Returns:
True on success, False otherwise
"""
if winsign.osslsigncode.is_signed(orig_path):
log.info("%s is already signed", orig_path)
return True
fmt, keyid = utils.split_autograph_format(fmt)
async def signer(digest, digest_algo):
try:
return await sign_hash_with_autograph(context, digest, fmt, keyid)
except Exception:
log.exception("Error signing authenticode hash with autograph")
raise
infile = orig_path
outfile = orig_path + "-new"
if "authenticode_ev" in fmt:
digest_algo = "sha256"
else:
digest_algo = "sha1"
if keyid:
certs = load_pem_certs(open(context.config[f"authenticode_cert_{keyid}"], "rb").read())
else:
certs = load_pem_certs(open(context.config["authenticode_cert"], "rb").read())
url = context.config["authenticode_url"]
timestamp_style = context.config["authenticode_timestamp_style"]
if fmt.endswith("authenticode_stub"):
crosscert = context.config["authenticode_cross_cert"]
else:
crosscert = None
if authenticode_comment and orig_path.endswith(".msi"):
log.info("Using comment '%s' to sign %s", authenticode_comment, orig_path)
elif authenticode_comment:
log.info("Not using specified comment to sign %s, not yet implemented for non *.msi files.", orig_path)
authenticode_comment = None
if not await winsign.sign.sign_file(
infile, outfile, digest_algo, certs, signer, url=url, comment=authenticode_comment, crosscert=crosscert, timestamp_style=timestamp_style,
):
raise IOError(f"Couldn't sign {orig_path}")
os.rename(outfile, infile)
return True
def test_timestamp_old(test_file, digest_algo, tmp_path, signing_keys,
httpserver):
"""Verify that we can sign with old style timestamps."""
signed_exe = tmp_path / "signed.exe"
priv_key = load_private_key(open(signing_keys[0], "rb").read())
certs = load_pem_certs(signing_keys[1].read_bytes())
def signer(digest, digest_algo):
return sign_signer_digest(priv_key, digest_algo, digest)
httpserver.serve_content(
(DATA_DIR / f"unsigned-{digest_algo}-ts-old.dat").read_bytes())
assert sign_file(
test_file,
signed_exe,
digest_algo,
certs,
signer,
timestamp_style="old",
# Comment this out to use a real timestamp server so that we can
# capture a response
timestamp_url=httpserver.url,
)
# Check that we have 3 certificates in the signature
if is_pefile(test_file):
with signed_exe.open("rb") as f:
certificates = get_certificates(f)
sigs = get_signatures_from_certificates(certificates)
assert len(certificates) == 1
assert len(sigs) == 1
assert len(sigs[0]["certificates"]) == 3
assert verify_pefile(f)
def test_sign_file_dummy(tmp_path, signing_keys):
"""Check that we can sign with an additional dummy certificate.
The extra dummy certs are used by the stub installer.
"""
test_file = DATA_DIR / "unsigned.exe"
signed_exe = tmp_path / "signed.exe"
priv_key = load_private_key(open(signing_keys[0], "rb").read())
certs = load_pem_certs(signing_keys[1].read_bytes())
def signer(digest, digest_algo):
return sign_signer_digest(priv_key, digest_algo, digest)
assert sign_file(test_file,
signed_exe,
"sha1",
certs,
signer,
crosscert=signing_keys[1])
# Check that we have 2 certificates in the signature
with signed_exe.open("rb") as f:
certificates = get_certificates(f)
sigs = get_signatures_from_certificates(certificates)
assert len(certificates) == 1
assert len(sigs) == 1
assert len(sigs[0]["certificates"]) == 2
async def async_main(argv=None):
"""Main CLI entry point for signing (async)."""
parser = build_parser()
args = parser.parse_args(argv)
logging.basicConfig(format="%(asctime)s - %(message)s",
level=args.loglevel)
if not args.priv_key:
if not (args.autograph_user and args.autograph_secret):
parser.error(
"--key, or all of --autograph-url, --autograph-user, and "
"--autograph-secret must be specified")
if not args.outfile:
args.outfile = args.infile
certs = []
certs_data = open(args.certs, "rb").read()
certs = load_pem_certs(certs_data)
priv_key = load_private_key(open(args.priv_key, "rb").read())
signer = key_signer(priv_key)
with tempfile.TemporaryDirectory() as d:
d = Path(d)
if args.infile == "-":
args.infile = d / "unsigned"
with args.infile.open("wb") as f:
_copy_stream(sys.stdin.buffer, f)
else:
args.infile = Path(args.infile)
if args.outfile == "-":
outfile = d / "signed"
else:
outfile = Path(args.outfile)
r = await sign_file(
args.infile,
outfile,
args.digest_algo,
certs,
signer,
url=args.url,
comment=args.comment,
timestamp_style=args.timestamp,
)
# TODO: Extra cross-cert
# TODO: Check with a cert chain
if not r:
return 1
if args.outfile == "-":
with outfile.open("rb") as f:
_copy_stream(f, sys.stdout.buffer)
return 0
def test_sign_file_badfile(tmp_path, signing_keys):
"""Verify that we can't sign non-exe files."""
test_file = Path(__file__)
signed_file = tmp_path / "signed.py"
priv_key = load_private_key(open(signing_keys[0], "rb").read())
certs = load_pem_certs(signing_keys[1].read_bytes())
def signer(digest, digest_algo):
return sign_signer_digest(priv_key, digest_algo, digest)
assert not sign_file(test_file, signed_file, "sha1", certs, signer)
async def test_sign(test_file, digest_algo, tmp_path, signing_keys):
"""Check that we can sign a PE file."""
signed_exe = tmp_path / "signed.exe"
priv_key = load_private_key(open(signing_keys[0], "rb").read())
certs = load_pem_certs(signing_keys[1].read_bytes())
# TODO: Make sure multiple works
cert = certs[0]
async def signer(digest, digest_algo):
return sign_signer_digest(priv_key, digest_algo, digest)
with test_file.open("rb") as infile, signed_exe.open("wb+") as outfile:
assert await sign_file(infile, outfile, digest_algo, cert, signer)
assert verify_pefile(outfile)
def test_sign_file_twocerts(tmp_path, signing_keys):
"""Check that we can include multiple certificates."""
test_file = DATA_DIR / "unsigned.exe"
signed_exe = tmp_path / "signed.exe"
priv_key = load_private_key(open(signing_keys[0], "rb").read())
certs = load_pem_certs(open(DATA_DIR / "twocerts.pem", "rb").read())
def signer(digest, digest_algo):
return sign_signer_digest(priv_key, digest_algo, digest)
assert sign_file(test_file, signed_exe, "sha1", certs, signer)
# Check that we have 2 certificates in the signature
with signed_exe.open("rb") as f:
certificates = get_certificates(f)
sigs = get_signatures_from_certificates(certificates)
assert len(certificates) == 1
assert len(sigs) == 1
assert len(sigs[0]["certificates"]) == 2
def test_timestamp_rfc3161(test_file, digest_algo, tmp_path, signing_keys,
httpserver):
"""Verify that we can sign with RFC3161 timestamps."""
signed_exe = tmp_path / "signed.exe"
priv_key = load_private_key(open(signing_keys[0], "rb").read())
certs = load_pem_certs(signing_keys[1].read_bytes())
def signer(digest, digest_algo):
return sign_signer_digest(priv_key, digest_algo, digest)
httpserver.serve_content(
(DATA_DIR / f"unsigned-{digest_algo}-ts-rfc3161.dat").read_bytes())
assert sign_file(
test_file,
signed_exe,
digest_algo,
certs,
signer,
timestamp_style="rfc3161",
# Comment this out to use a real timestamp server so that we can
# capture a response
timestamp_url=httpserver.url,
)
# Check that we have 1 certificate in the signature,
# and have a counterSignature section
if is_pefile(test_file):
with signed_exe.open("rb") as f:
certificates = get_certificates(f)
sigs = get_signatures_from_certificates(certificates)
assert len(certificates) == 1
assert len(sigs) == 1
assert len(sigs[0]["certificates"]) == 1
assert any((sigs[0]["signerInfos"][0]["unauthenticatedAttributes"]
[i]["type"] == id_timestampSignature) for i in range(
len(sigs[0]["signerInfos"][0]
["unauthenticatedAttributes"])))
assert verify_pefile(f)
async def sign_authenticode_file(context, orig_path, fmt):
"""Sign a file in-place with authenticode, using autograph as a backend.
Args:
context (Context): the signing context
orig_path (str): the source file to sign
fmt (str): the format to sign with
Returns:
True on success, False otherwise
"""
if winsign.osslsigncode.is_signed(orig_path):
log.info("%s is already signed", orig_path)
return True
async def signer(digest, digest_algo):
try:
return await sign_hash_with_autograph(context, digest, fmt)
except Exception:
log.exception("Error signing authenticode hash with autograph")
raise
infile = orig_path
outfile = orig_path + "-new"
digest_algo = "sha1"
certs = load_pem_certs(open(context.config["authenticode_cert"], "rb").read())
url = context.config["authenticode_url"]
timestamp_style = context.config["authenticode_timestamp_style"]
if fmt.endswith("authenticode_stub"):
crosscert = context.config["authenticode_cross_cert"]
else:
crosscert = None
if not await winsign.sign.sign_file(infile, outfile, digest_algo, certs, signer, url=url, crosscert=crosscert, timestamp_style=timestamp_style):
raise IOError(f"Couldn't sign {orig_path}")
os.rename(outfile, infile)
return True
def test_sign_file(test_file, digest_algo, tmp_path, signing_keys):
"""Check that we can sign with the osslsign wrapper."""
signed_exe = tmp_path / "signed.exe"
priv_key = load_private_key(open(signing_keys[0], "rb").read())
certs = load_pem_certs(signing_keys[1].read_bytes())
def signer(digest, digest_algo):
return sign_signer_digest(priv_key, digest_algo, digest)
assert sign_file(test_file, signed_exe, digest_algo, certs, signer)
# Check that we have 1 certificate in the signature
if test_file in TEST_PE_FILES:
assert is_pefile(test_file)
with signed_exe.open("rb") as f:
certificates = get_certificates(f)
sigs = get_signatures_from_certificates(certificates)
assert len(certificates) == 1
assert len(sigs) == 1
assert len(sigs[0]["certificates"]) == 1
assert verify_pefile(f)
async def sign_file(
infile,
outfile,
digest_algo,
certs,
signer,
url=None,
comment=None,
crosscert=None,
timestamp_style=None,
timestamp_url=None,
):
"""Sign a PE or MSI file.
Args:
infile (str): Path to the unsigned file
outfile (str): Path to where the signed file will be written
digest_algo (str): Which digest algorithm to use. Generally 'sha1' or 'sha256'
certs (str): Path to where the PEM encoded public certificate(s) are located
signer (function): Function that takes (digest, digest_algo) and
returns bytes of the signature. Normally this will
be using a private key object to sign the digest.
url (str): A URL to embed into the signature
comment (str): A string to embed into the signature
crosscert (str): Extra certificates to attach to the signature
timestamp_style (str): What kind of signed timestamp to include in the
signature. Can be None, 'old', or 'rfc3161'.
timestamp_url (str): URL for the timestamp server to use. Required if
timestamp_style is set.
Returns:
True on success
False otherwise
"""
infile = Path(infile)
outfile = Path(outfile)
try:
log.debug("Generating dummy signature")
old_sig = get_dummy_signature(
infile, digest_algo, url=url, comment=comment, crosscert=crosscert
)
except OSError:
log.error("Couldn't generate dummy signature")
log.debug("Exception:", exc_info=True)
return False
try:
log.debug("Re-signing with real keys")
old_sig = get_signeddata(old_sig)
if crosscert:
crosscert = Path(crosscert)
certs.extend(load_pem_certs(crosscert.read_bytes()))
newsig = await resign(old_sig, certs, signer)
except Exception:
log.error("Couldn't re-sign")
log.debug("Exception:", exc_info=True)
return False
if timestamp_style == "old":
ci = der_decode(newsig, ContentInfo())[0]
sig = der_decode(ci["content"], SignedData())[0]
sig = await winsign.timestamp.add_old_timestamp(sig, timestamp_url)
ci = ContentInfo()
ci["contentType"] = id_signedData
ci["content"] = sig
newsig = der_encode(ci)
elif timestamp_style == "rfc3161":
ci = der_decode(newsig, ContentInfo())[0]
sig = der_decode(ci["content"], SignedData())[0]
sig = await winsign.timestamp.add_rfc3161_timestamp(
sig, digest_algo, timestamp_url
)
ci = ContentInfo()
ci["contentType"] = id_signedData
ci["content"] = sig
newsig = der_encode(ci)
try:
log.debug("Attaching new signature")
write_signature(infile, outfile, newsig)
except Exception:
log.error("Couldn't write new signature")
log.debug("Exception:", exc_info=True)
return False
log.debug("Done!")
return True
