def create_degenerate_pkcs7(*certificates: List[x509.Certificate]) -> ContentInfo:
"""Produce a PKCS#7 Degenerate case.
The degenerate case is a SignedData content type in which there are no signers. Certificates are disseminated
via the ``certificates`` attribute.
Args:
*certificates (List[x509.Certificate]): The certificates to attach to the degenerate pkcs#7 payload.
The first must always be the issued certificate.
Returns:
ContentInfo: The ContentInfo containing a SignedData structure.
"""
certificates_der = [c.public_bytes(serialization.Encoding.DER) for c in certificates]
certificates_asn1 = [parse_certificate(der_bytes) for der_bytes in certificates_der]
# draft-gutmann-scep 3.4. content type must be omitted
empty = ContentInfo({
'content_type': ContentType('data')
})
sd_certificates = CertificateSet([CertificateChoices('certificate', asn1) for asn1 in certificates_asn1])
sd = SignedData({
'version': CMSVersion(1),
'encap_content_info': empty,
'digest_algorithms': DigestAlgorithms([]),
'certificates': sd_certificates,
'signer_infos': SignerInfos([]),
'crls': RevocationInfoChoices([]),
})
return ContentInfo({
'content_type': ContentType('signed_data'),
'content': sd,
})
def create_degenerate_certificate(certificate: x509.Certificate) -> ContentInfo:
"""Produce a PKCS#7 Degenerate case with a single certificate.
Args:
certificate (x509.Certificate): The certificate to attach to the degenerate pkcs#7 payload.
Returns:
ContentInfo: The ContentInfo containing a SignedData structure.
"""
der_bytes = certificate.public_bytes(
serialization.Encoding.DER
)
asn1cert = parse_certificate(der_bytes)
empty = ContentInfo({
'content_type': ContentType('data')
})
sd = SignedData({
'version': CMSVersion(1),
'encap_content_info': empty,
'digest_algorithms': DigestAlgorithms([]),
'certificates': CertificateSet([CertificateChoices('certificate', asn1cert)]),
'signer_infos': SignerInfos([]),
'crls': RevocationInfoChoices([]),
})
return ContentInfo({
'content_type': ContentType('signed_data'),
'content': sd,
})
def finalize(self, digest_algorithm):
"""Build all data structures from the given parameters and return the top level contentInfo.
Returns:
ContentInfo: The PKIMessage
"""
pkcs_pki_envelope = self._pki_envelope
pkienvelope_content_info = ContentInfo({
'content_type':
ContentType(u'enveloped_data'),
'content':
pkcs_pki_envelope,
})
# NOTE: This might not be needed for the degenerate CertRep
encap_info = ContentInfo({
'content_type': ContentType(u'data'),
'content': pkienvelope_content_info.dump()
})
# Calculate digest on encrypted content + signed_attrs
d = digest_for_data(algorithm=digest_algorithm,
data=pkienvelope_content_info.dump())
# Now start building SignedData
signer_infos = self._build_signerinfos(pkienvelope_content_info.dump(),
d, self._cms_attributes)
certificates = self._certificates
da_id = DigestAlgorithmId(six.text_type(digest_algorithm))
da = DigestAlgorithm({u'algorithm': da_id})
das = DigestAlgorithms([da])
sd = SignedData({
'version': 1,
'certificates': certificates,
'signer_infos': signer_infos,
'digest_algorithms': das,
'encap_content_info':
encap_info, # should point to type data + content contentinfo
})
ci = ContentInfo({
'content_type': ContentType(u'signed_data'),
'content': sd,
})
return ci
def make_cms(
cert: Certificate,
hash_type: int,
signed_attrs: CMSAttributes,
sig: bytes,
unsigned_attrs: Optional[CMSAttributes],
) -> ContentInfo:
sid = SignerIdentifier(
"issuer_and_serial_number",
IssuerAndSerialNumber({
"issuer":
cert["tbs_certificate"]["issuer"],
"serial_number":
cert["tbs_certificate"]["serial_number"],
}),
)
dg_algo = DigestAlgorithm({"algorithm": _get_digest_algo(hash_type)})
sig_algo = SignedDigestAlgorithm(
{"algorithm": SignedDigestAlgorithmId("rsassa_pkcs1v15")})
sig_info = SignerInfo({
"version": CMSVersion(1),
"sid": sid,
"digest_algorithm": dg_algo,
"signed_attrs": signed_attrs,
"signature_algorithm": sig_algo,
"signature": OctetString(sig),
"unsigned_attrs": unsigned_attrs,
})
certs = make_certificate_chain(cert)
signed_data = SignedData({
"version":
CMSVersion(1),
"digest_algorithms": [dg_algo],
"encap_content_info":
ContentInfo({"content_type": ContentType("data")}),
"certificates":
certs,
"signer_infos": [sig_info],
})
return ContentInfo({
"content_type": ContentType.unmap("signed_data"),
"content": signed_data
})
def finalize(self) -> Tuple[EnvelopedData, Union[TripleDES, AES], bytes]:
"""Encrypt the data and process the key using all available recipients.
Returns:
EnvelopedData, TripleDES, iv (bytes): The PKCSPKIEnvelope structure, The symmetric key, and the IV for
the symmetric key.
"""
sym_key, iv, ciphertext = self._encrypt_data(self._data)
eci = EncryptedContentInfo({
'content_type':
ContentType('data'),
'content_encryption_algorithm':
EncryptionAlgorithm({
'algorithm': self._encryption_algorithm_id,
'parameters': OctetString(iv),
}),
'encrypted_content':
ciphertext,
})
recipients = [
self._build_recipient_info(sym_key.key, recipient)
for recipient in self._recipients
]
recipient_infos = RecipientInfos(recipients)
ed = EnvelopedData({
'version': 1,
'recipient_infos': recipient_infos,
'encrypted_content_info': eci,
})
return ed, sym_key, iv
def _build_signerinfos(self, content: bytes, content_digest: bytes, cms_attributes: List[CMSAttribute]) -> SignerInfos:
"""Build all signer infos and return a collection.
Returns:
SignerInfos: all signers
"""
return SignerInfos(signer.sign(content, ContentType('data'), content_digest, cms_attributes) for signer in self._signers)
def make_signed_attrs(digest: bytes, hash_type: int) -> CMSAttributes:
content_type = CMSAttribute({
"type": CMSAttributeType.unmap("content_type"),
"values": [ContentType.unmap("data")],
})
time_now = UTCTime()
time_now.set(datetime.now(timezone.utc))
signing_time = CMSAttribute({
"type": CMSAttributeType.unmap("signing_time"),
"values": [time_now]
})
message_digest = CMSAttribute({
"type":
CMSAttributeType.unmap("message_digest"),
"values": [OctetString(digest)],
})
ha_v1 = make_hash_agility_v1(digest)
ha_v2 = make_hash_agility_v2(digest, hash_type)
return CMSAttributes(
[content_type, signing_time, message_digest, ha_v1, ha_v2])
def finalize(self) -> ContentInfo:
"""Build all data structures from the given parameters and return the top level contentInfo.
Returns:
ContentInfo: The PKIMessage
"""
pkcs_pki_envelope = self._pki_envelope
pkienvelope_content_info = ContentInfo({
'content_type': ContentType('enveloped_data'),
'content': pkcs_pki_envelope,
})
# NOTE: This might not be needed for the degenerate CertRep
encap_info = ContentInfo({
'content_type': ContentType('data'),
'content': pkienvelope_content_info.dump()
})
# encap_info_degen = ContentInfo({
# 'content_type': ContentType('data'),
# 'content': pkcs_pki_envelope.dump()
# })
# Calculate digest on encrypted content + signed_attrs
#digest = hashes.Hash(hashes.SHA256(), backend=default_backend())
digest = hashes.Hash(hashes.SHA512(), backend=default_backend())
#digest = hashes.Hash(hashes.SHA1(), backend=default_backend())
# digest.update(pkcs_pki_envelope.dump())
digest.update(pkienvelope_content_info.dump())
d = digest.finalize()
# Now start building SignedData
# signer_infos = self._build_signerinfos(pkcs_pki_envelope.dump(), d, self._cms_attributes)
signer_infos = self._build_signerinfos(pkienvelope_content_info.dump(), d, self._cms_attributes)
certificates = self._certificates
#da_id = DigestAlgorithmId('sha256')
# SHA-1 works for macOS
# da_id = DigestAlgorithmId('sha1')
da_id = DigestAlgorithmId('sha512')
da = DigestAlgorithm({'algorithm': da_id})
das = DigestAlgorithms([da])
sd = SignedData({
'version': 1,
'certificates': certificates,
'signer_infos': signer_infos,
'digest_algorithms': das,
'encap_content_info': encap_info, # should point to type data + content contentinfo
})
ci = ContentInfo({
'content_type': ContentType('signed_data'),
'content': sd,
})
return ci
def sign(self):
h = hashes.Hash(hashes.SHA256(), backend=default_backend())
h.update(self._content_mime.as_bytes())
message_digest = h.finalize()
cs = CertificateSet()
cs.append(load(self._certificate.public_bytes(Encoding.DER)))
for ca_cert in self._ca:
cs.append(load(ca_cert.public_bytes(Encoding.DER)))
ec = ContentInfo({
'content_type': ContentType('data'),
})
sident = SignerIdentifier({
'issuer_and_serial_number':
IssuerAndSerialNumber({
'issuer':
load(self._issuer_name.public_bytes(default_backend())),
'serial_number':
self._cert_serial,
})
})
certv2 = ESSCertIDv2({
'hash_algorithm':
DigestAlgorithm({'algorithm': DigestAlgorithmId('sha256')}),
'cert_hash':
OctetString(self._certificate.fingerprint(hashes.SHA256())),
'issuer_serial':
IssuerSerial({
'issuer':
load(self._issuer_name.public_bytes(default_backend())),
'serial_number':
self._cert_serial,
}),
})
now = datetime.now().replace(microsecond=0,
tzinfo=pytz.utc) # .isoformat()
sattrs = CMSAttributes({
CMSAttribute({
'type': CMSAttributeType('content_type'),
'values': ["data"]
}),
CMSAttribute({
'type': CMSAttributeType('message_digest'),
'values': [message_digest]
}),
CMSAttribute({
'type': CMSAttributeType('signing_time'),
'values': (Time({'utc_time': UTCTime(now)}), )
}),
CMSAttribute({
'type':
CMSAttributeType('signing_certificate_v2'),
'values': [SigningCertificateV2({'certs': (certv2, )})]
})
})
signature = self._private_key.sign(sattrs.dump(), padding.PKCS1v15(),
hashes.SHA256()) #
si = SignerInfo({
'version':
'v1',
'sid':
sident,
'digest_algorithm':
DigestAlgorithm({'algorithm': DigestAlgorithmId('sha256')}),
'signed_attrs':
sattrs,
'signature_algorithm':
SignedDigestAlgorithm(
{'algorithm': SignedDigestAlgorithmId('rsassa_pkcs1v15')}),
'signature':
signature,
})
da = DigestAlgorithms(
(DigestAlgorithm({'algorithm': DigestAlgorithmId('sha256')}), ))
signed_data = SignedData({
'version': 'v1',
'encap_content_info': ec,
'certificates': cs,
'digest_algorithms': da,
'signer_infos': SignerInfos((si, ))
})
ci = ContentInfo({
'content_type': ContentType('signed_data'),
'content': signed_data
})
self._signature_mime = MIMEApplication(ci.dump(),
_subtype="pkcs7-signature",
name="smime.p7s",
policy=email.policy.SMTPUTF8)
self._signature_mime.add_header('Content-Disposition',
'attachment; filename=smime.p7s')
super(CADESMIMESignature, self).attach(self._content_mime)
super(CADESMIMESignature, self).attach(self._signature_mime)
def sign(self):
h = hashes.Hash(hashes.SHA256(), backend=default_backend())
h.update(self._content_mime.as_bytes())
message_digest = h.finalize()
cs = CertificateSet()
cs.append(load(self._certificate.public_bytes(Encoding.DER)))
for ca_cert in self._ca:
cs.append(load(ca_cert.public_bytes(Encoding.DER)))
ec = EncapsulatedContentInfo({
'content_type':
ContentType('data'),
'content':
ParsableOctetString(self._content_mime.as_bytes())
})
sident = SignerIdentifier({
'issuer_and_serial_number':
IssuerAndSerialNumber({
'issuer':
load(self._issuer_name.public_bytes(default_backend())),
'serial_number':
self._cert_serial,
})
})
certv2 = ESSCertIDv2({
'hash_algorithm':
DigestAlgorithm({'algorithm': DigestAlgorithmId('sha256')}),
'cert_hash':
OctetString(self._certificate.fingerprint(hashes.SHA256())),
'issuer_serial':
IssuerSerial({
'issuer':
load(
self._issuer_name.public_bytes(default_backend())
), #[GeneralName({'directory_name': self._issuer_name.public_bytes(default_backend())})],
'serial_number':
self._cert_serial,
}),
})
now = datetime.now().replace(microsecond=0, tzinfo=pytz.utc)
sattrs = CMSAttributes({
CMSAttribute({
'type': CMSAttributeType('content_type'),
'values': ["data"]
}),
CMSAttribute({
'type': CMSAttributeType('message_digest'),
'values': [message_digest]
}),
CMSAttribute({
'type': CMSAttributeType('signing_time'),
'values': (Time({'utc_time': UTCTime(now)}), )
}),
# isti k v
CMSAttribute({
'type':
CMSAttributeType('signing_certificate_v2'),
'values': [SigningCertificateV2({'certs': (certv2, )})]
})
})
signature = self._private_key.sign(sattrs.dump(), padding.PKCS1v15(),
hashes.SHA256())
si = SignerInfo({
'version':
'v1',
'sid':
sident,
'digest_algorithm':
DigestAlgorithm({'algorithm': DigestAlgorithmId('sha256')}),
'signed_attrs':
sattrs,
'signature_algorithm':
SignedDigestAlgorithm(
{'algorithm': SignedDigestAlgorithmId('rsassa_pkcs1v15')}),
'signature':
signature,
})
da = DigestAlgorithms(
(DigestAlgorithm({'algorithm': DigestAlgorithmId('sha256')}), ))
signed_data = SignedData({
'version': 'v3',
'encap_content_info': ec,
'certificates': cs,
'digest_algorithms': da,
'signer_infos': SignerInfos((si, ))
})
ci = ContentInfo({
'content_type': ContentType('signed_data'),
'content': signed_data
})
self.set_payload(ci.dump())
encode_base64(self)