13 - PE Authenticode
--------------------

This tutorial explains how to process and verify PE authenticode with LIEF

By Romain Thomas - `@rh0main <https://twitter.com/rh0main>`_

------

Introduction
~~~~~~~~~~~~

PE authenticode is the signature scheme used by Windows to sign and verify the integrity of PE executables.
The signature is associated with the data directory :attr:`~lief.PE.DATA_DIRECTORY.CERTIFICATE_TABLE`
that is not always tied to a section (it implies that the signature is not necessarily mapped in memory).
This signature is wrapped in a PKCS #7 container with custom object types as defined
in the official documentation [#]_.

This signature is not new in PE files and since the beginning of LIEF, we aimed to parse it.
Before the version :ref:`v0.11.0 <release-0110>`, the implementation was somehow incomplete and inaccurate but
since the version :ref:`v0.11.0 <release-0110>` and thanks to the sponsoring of the `CERT Gouvernemental of Luxembourg <https://www.govcert.lu/en/>`_,
we refactored the design of the authenticode parser [#]_ and we implemented functions to verify the signature.


Exploring PKCS #7 Signature
~~~~~~~~~~~~~~~~~~~~~~~~~~~

LIEF API tries to expose most of the internal components of the PKCS #7 container associated with the
Aunthenticode.
First, we can access the PE's signature through the :attr:`lief.PE.Binary.signatures` attribute
[#]_:

.. code-block:: python

   import lief
   pe = lief.parse("avast_free_antivirus_setup_online.exe")
   print(len(pe.signatures))

   signature = pe.signatures[0]

Although we usually find only **one** signature, PE executables can embed multiple signatures thanks to
the ``/as`` command of ``signtool.exe``. This is why the :attr:`~lief.PE.Binary.signatures` attribute returns an
**iterator** over the signatures parsed by LIEF.

The :class:`signature <lief.PE.Signature>` variable is actually a :class:`lief.PE.Signature` object which basically
mirrors the PKCS #7 container plus some method to verify its integrity.

Within this object, we can access the following attributes:

* :class:`~lief.PE.x509` certificates used to sign the executable: :attr:`lief.PE.Signature.certificates`
* The :class:`~lief.PE.ContentInfo` object that contains the authentihash value: :attr:`lief.PE.ContentInfo.digest`
* The :class:`~lief.PE.SignerInfo` structure: :attr:`lief.PE.Signature.signers`

  .. note::

    While the PKCS #7 standard enables multiple signers, Microsoft specifications require **one** and **only one**
    signer.

The ``__str__()`` functions of these objects are overloaded so that we can pretty-print the content of these objects easily:

.. code-block:: python

   # Print certificates information
   for crt in signature.certificates:
     print(crt)

   # Print the authentihash value embedded in the signature
   print(signature.content_info.digest.hex())

   # Print signer information
   print(signature.signers[0])

.. code-block:: text

  cert. version     : 3
  serial number     : 04:09:18:1B:5F:D5:BB:66:75:53:43:B5:6F:95:50:08
  issuer name       : C=US, O=DigiCert Inc, OU=www.digicert.com, CN=DigiCert Assured ID Root CA
  subject name      : C=US, O=DigiCert Inc, OU=www.digicert.com, CN=DigiCert SHA2 Assured ID Code Signing CA
  issued  on        : 2013-10-22 12:00:00
  expires on        : 2028-10-22 12:00:00
  signed using      : RSA with SHA-256
  RSA key size      : 2048 bits
  basic constraints : CA=true, max_pathlen=0
  key usage         : Digital Signature, Key Cert Sign, CRL Sign
  ext key usage     : Code Signing

  cert. version     : 3
  serial number     : 09:70:EF:4B:AD:5C:C4:4A:1C:2B:C3:D9:64:01:67:4C
  issuer name       : C=US, O=DigiCert Inc, OU=www.digicert.com, CN=DigiCert SHA2 Assured ID Code Signing CA
  subject name      : C=CZ, L=Praha, O=Avast Software s.r.o., OU=RE stapler cistodc, CN=Avast Software s.r.o.
  issued  on        : 2020-04-02 00:00:00
  expires on        : 2023-03-09 12:00:00
  signed using      : RSA with SHA-256
  RSA key size      : 2048 bits
  basic constraints : CA=false
  key usage         : Digital Signature
  ext key usage     : Code Signing

  a738da4446a4e78ab647db7e53427eb07961c994317f4c59d7edbea5cc786d80
  SHA_256/RSA - C=US, O=DigiCert Inc, OU=www.digicert.com, CN=DigiCert SHA2 Assured ID Code Signing CA - 4 auth attr - 1 unauth attr

Regarding the PE files, the authentihash is computed through the function :meth:`lief.PE.Binary.authentihash`
which takes a :class:`lief.PE.ALGORITHMS` enum as parameter to define which hash algorithm must be
used to compute the digest.

For instance, to compute the SHA-256 value of the authenticode, we just have to pass :attr:`lief.PE.ALGORITHMS.SHA_256`:

.. code-block:: python

   print(pe.authentihash(lief.PE.ALGORITHMS.SHA_256).hex())

.. code-block:: text

  a738da4446a4e78ab647db7e53427eb07961c994317f4c59d7edbea5cc786d80

.. note::

  To compare the :meth:`lief.PE.Binary.authentihash` value with the signed one (i.e. :attr:`lief.PE.ContentInfo.digest`)
  we must use the same hash algorithm as defined by :attr:`lief.PE.Signature.digest_algorithm`

We also expose in the Python API, shortcut attributes to compute the authentihash values for:

+----------------+---------------------------------------------+
| Hash Algorithm | Binary's Attribute                          |
+================+=============================================+
| MD5            | :attr:`~lief.PE.Binary.authentihash_md5`    |
+----------------+---------------------------------------------+
| SHA1           | :attr:`~lief.PE.Binary.authentihash_sha1`   |
+----------------+---------------------------------------------+
| SHA-256        | :attr:`~lief.PE.Binary.authentihash_sha256` |
+----------------+---------------------------------------------+
| SHA-512        | :attr:`~lief.PE.Binary.authentihash_sha512` |
+----------------+---------------------------------------------+

LIEF also exposes the original raw signature blob through the property :attr:`lief.PE.Signature.raw_der` which
enables to export the signature:

.. code-block:: python

  from pathlib import Path

  Path("/tmp/extracted.p7b").write_bytes(signature.raw_der)

Then, we can use ``openssl`` to process its content:

.. code-block:: text

   $ openssl pkcs7 -inform der -print -in /tmp/extracted.p7b -noout -text
   ...
        sig_alg:
          algorithm: sha256WithRSAEncryption (1.2.840.113549.1.1.11)
          parameter: NULL
        signature:  (0 unused bits)
          0000 - 31 c3 a7 f3 70 e3 2c 49-15 bd f4 09 6c 27 4e   1...p.,I....l'N
          000f - 00 a9 23 df cb ea 7f 99-55 cb 24 88 75 e8 c4   ..#.....U.$.u..
          001e - de 48 4f 70 dd 2a 27 5c-df be 36 f6 84 0d ad   .HOp.*'\..6....
          002d - 35 5e 65 f7 af 55 01 7a-2d 01 18 a0 d6 98 a4   5^e..U.z-......
          003c - d1 bd 19 e9 a4 03 f4 a3-4d 12 6e 72 5f 6b 3a   ........M.nr_k:
          004b - b8 de 45 f1 63 80 b0 47-42 f6 38 b8 e7 5b dd   ..E.c..GB.8..[.
          005a - cf f2 f8 c2 61 4b 2c 19-b7 7d 78 8f 2e 0c b0   ....aK,..}x....
          0069 - 7c f2 d9 8e 9f 65 4e 21-63 19 6a 5b 0c 91 12   |....eN!c.j[...
          0078 - 44 29 fe 91 d5 6f 5d 9c-4d 7b a1 74 c6 69 d9   D)...o].M{.t.i.
          0087 - e7 23 26 54 35 5c 38 33-c5 a7 92 0d 70 a5 2a   .#&T5\83....p.*
          0096 - 33 77 4a fc 86 b0 fa 59-2f 24 f6 a1 45 b2 09   3wJ....Y/$..E..
          00a5 - 75 2d a1 81 68 e4 67 11-46 e3 fb bf 0c c5 d5   u-..h.g.F......
          00b4 - d7 7b 7b 35 fb d6 e8 4a-c9 13 82 82 a7 0c 3e   .{{5...J......>
          00c3 - 6f 61 e0 37 15 e0 37 5d-b8 22 14 ad 54 58 0e   oa.7..7]."..TX.
          00d2 - 95 6c 2b b1 d2 c7 6c 86-a1 9f fa d8 37 ca f7   .l+...l.....7..
          00e1 - 56 75 b0 9d df 7c 46 43-20 87 8a a3 81 47 82   Vu...|FC ....G.
          00f0 - 99 57 87 12 46 96 02 7c-a7 77 b9 42 4d c8 05   .W..F..|.w.BM..
          00ff - 0a                                             .
    crl:
      <ABSENT>
    signer_info:
        version: 1
        issuer_and_serial:
          issuer: C=US, O=DigiCert Inc, OU=www.digicert.com, CN=DigiCert SHA2 Assured ID Code Signing CA
          serial: 12549442701880659695003200114191853388
        digest_alg:
          algorithm: sha256 (2.16.840.1.101.3.4.2.1)
          parameter: NULL
        auth_attr:
            object: contentType (1.2.840.113549.1.9.3)
            set:
              OBJECT:undefined (1.3.6.1.4.1.311.2.1.4)

            object: undefined (1.3.6.1.4.1.311.2.1.11)

The `authenticode_reader.py <https://github.com/lief-project/LIEF/blob/master/examples/python/authenticode/authenticode_reader.py>`_
script located in the `examples/ <https://github.com/lief-project/LIEF/tree/master/examples/python/authenticode>`_ directory
can also be used to inspect the signature:

.. code-block:: console

   $ python authenticode_reader.py --all avast_free_antivirus_setup_online.exe

.. code-block:: text

   Signature version : 1
   Digest Algorithm  : ALGORITHMS.SHA_256
   Content Info:
     Content Type    : 1.3.6.1.4.1.311.2.1.4 (SPC_INDIRECT_DATA_CONTENT)
     Digest Algorithm: ALGORITHMS.SHA_256
     Digest          : a738da4446a4e78ab647db7e53427eb07961c994317f4c59d7edbea5cc786d80
   Certificates
     Version            : 3
     Issuer             : C=US, O=DigiCert Inc, OU=www.digicert.com, CN=DigiCert Assured ID Root CA
     Subject            : C=US, O=DigiCert Inc, OU=www.digicert.com, CN=DigiCert SHA2 Assured ID Code Signing CA
     Serial Number      : 0409181b5fd5bb66755343b56f955008
     Signature Algorithm: SHA256_WITH_RSA_ENCRYPTION
     Valid from         : 2013/10/22 - 12:00:00
     Valid to           : 2028/10/22 - 12:00:00
     Key usage          : CRL_SIGN - KEY_CERT_SIGN - DIGITAL_SIGNATURE
     Ext key usage      : CODE_SIGNING
     RSA key size       : 2048
     ===========================================
     Version            : 3
     Issuer             : C=US, O=DigiCert Inc, OU=www.digicert.com, CN=DigiCert SHA2 Assured ID Code Signing CA
     Subject            : C=CZ, L=Praha, O=Avast Software s.r.o., OU=RE stapler cistodc, CN=Avast Software s.r.o.
     Serial Number      : 0970ef4bad5cc44a1c2bc3d96401674c
     Signature Algorithm: SHA256_WITH_RSA_ENCRYPTION
     Valid from         : 2020/04/02 - 00:00:00
     Valid to           : 2023/03/09 - 12:00:00
     Key usage          : DIGITAL_SIGNATURE
     Ext key usage      : CODE_SIGNING
     RSA key size       : 2048
     ===========================================
   Signer(s)
     Version             : 1
     Serial Number       : 0970ef4bad5cc44a1c2bc3d96401674c
     Issuer              : C=US, O=DigiCert Inc, OU=www.digicert.com, CN=DigiCert SHA2 Assured ID Code Signing CA
     Digest Algorithm    : ALGORITHMS.SHA_256
     Encryption Algorithm: ALGORITHMS.RSA
     Encrypted Digest    : 758db1f480eb25bada6c ...
     Authenticated attributes:
        Content Type OID: 1.3.6.1.4.1.311.2.1.4 (SPC_INDIRECT_DATA_CONTENT)
        MS Statement type OID: 1.3.6.1.4.1.311.2.1.21 (INDIVIDUAL_CODE_SIGNING)
        Info: http://www.avast.com
        PKCS9 Message Digest: 3983816a7d1c62962540ec66fa8790fa45d1063cb23e933677de459f0b73c577
     Un-authenticated attributes:
        Generic Type 1.3.6.1.4.1.311.3.3.1 (MS_COUNTER_SIGN)

Verifying the Signature
~~~~~~~~~~~~~~~~~~~~~~~

Besides the fact that LIEF can parse PE's authenticode signature, LIEF can also verify the integrity of the authentihash
thanks to the method: :meth:`lief.PE.Binary.verify_signature` which outputs :attr:`lief.PE.Signature.VERIFICATION_FLAGS.OK`
if the signature is valid or another enum (see: :attr:`lief.PE.Signature.VERIFICATION_FLAGS`) when it is invalid:

.. code-block:: python

   pe = lief.parse("avast_free_antivirus_setup_online.exe")
   print(pe.verify_signature()) # lief.PE.Signature.VERIFICATION_FLAGS.OK

We can also verify a PE binary with a **detached signature** by providing a :class:`signature <lief.PE.Signature>`
object to :meth:`~lief.PE.Binary.verify_signature`:

.. code-block:: python
   :emphasize-lines: 3,4

   pe = lief.parse("avast_free_antivirus_setup_online.exe")

   detached_sig = lief.PE.Signature.parse("/tmp/detached.p7b")
   print(pe.verify_signature(detached_sig))

The verification process does not rely on an external component (i.e. neither openssl or WinTrust API) but we try
to reproduce the same checks as described in the RFC(s) and the official documentation of the Authenticode
[#]_.

These checks include:

A. Check the integrity of the signature (:meth:`lief.PE.Signature.check()`):

   1. There is ONE and only ONE :class:`~lief.PE.SignerInfo`
   2. Digest algorithms are consistent
      (:attr:`Signature.digest_algorithm <lief.PE.Signature.digest_algorithm>` ``==`` :attr:`ContentInfo.digest_algorithm <lief.PE.ContentInfo.digest_algorithm>`  ``==`` :attr:`SignerInfo.digest_algorithm <lief.PE.SignerInfo.digest_algorithm>`)
   3. If the :class:`~lief.PE.SignerInfo` has authenticated attributes, check their integrity. Otherwise, check
      the integrity of the :class:`~lief.PE.ContentInfo` against the Signer's certificate.
   4. If they are authenticated attributes, check that there is a
      :class:`lief.PE.PKCS9MessageDigest` attribute whose the :attr:`~lief.PE.PKCS9MessageDigest.digest`
      matches the hash of the :class:`~lief.PE.ContentInfo`
   5. If there is a counter signature in the **un-authenticated attributes**, verify its integrity and check
      that it wraps a valid *timestamping*.
   6. Check the expiration of the certificates according to the potential *timestamping*

B. If the signature is valid, check that :attr:`lief.PE.ContentInfo.digest` matches the computed
   :meth:`~lief.PE.Binary.authentihash`

These checks are the default behavior of the :meth:`~lief.PE.Binary.verify_signature`. Nevertheless, you could
pass :class:`lief.PE.Signature.VERIFICATION_CHECKS` flags to customize its behavior:

:Hash Only:

    By using :attr:`VERIFICATION_CHECKS.HASH_ONLY <lief.PE.Signature.VERIFICATION_CHECKS.HASH_ONLY>`, it only performs
    step ``B)`` (i.e. check the authentihash values regardless of the signature integrity)

    .. code-block:: python

      pe.verify_signature(lief.PE.VERIFICATION_CHECKS.HASH_ONLY)


:Lifetime Signing:

    By using :attr:`VERIFICATION_CHECKS.LIFETIME_SIGNING <lief.PE.Signature.VERIFICATION_CHECKS.LIFETIME_SIGNING>`, timestamped
    signatures can expire if their certificate expired. It has the same meaning as `WTD_LIFETIME_SIGNING_FLAG <https://docs.microsoft.com/en-us/windows/win32/api/wintrust/ns-wintrust-wintrust_data#WTD_LIFETIME_SIGNING_FLAG>`_

    .. code-block:: python

      pe.verify_signature(lief.PE.VERIFICATION_CHECKS.LIFETIME_SIGNING)
      signature.check(lief.PE.VERIFICATION_CHECKS.LIFETIME_SIGNING)


:Skip Cerificate Check Time:

    By using :attr:`VERIFICATION_CHECKS.SKIP_CERT_TIME <lief.PE.Signature.VERIFICATION_CHECKS.SKIP_CERT_TIME>`,
    LIEF doesn't raise an error if the certificate(s) expired.

    .. code-block:: python

      # Returns lief.PE.Signature.VERIFICATION_FLAGS.OK even though
      # the certificates expired
      pe.verify_signature(lief.PE.VERIFICATION_CHECKS.SKIP_CERT_TIME)
      signature.check(lief.PE.VERIFICATION_CHECKS.SKIP_CERT_TIME)

.. note::

  To verify the integrity of a :class:`~lief.PE.Signature` object, you can use
  :meth:`lief.PE.Signature.check`


Certificate Chain of Trust
~~~~~~~~~~~~~~~~~~~~~~~~~~

Last but not least, we can also verify the certificates chain thanks to:

1. :meth:`lief.PE.x509.verify`
2. :meth:`lief.PE.x509.is_trusted_by`

:meth:`~lief.PE.x509.verify` aims to verify a signed certificate from its CA. Given a CA :class:`~lief.PE.x509`
certificate, ``CA.verify(signed)`` verifies that the ``signed`` parameter has been signed by ``CA``.

On the other hand, :meth:`~lief.PE.x509.is_trusted_by` can be used to check that a given :class:`~lief.PE.x509`
certificate is verified against a **list of certificates**:

.. code-block:: python

  CA_BUNDLE = lief.PE.x509.parse("ms_bundle.pem")
  signer = signature.signers[0]
  print(signer.cert.is_trusted_by(CA_BUNDLE))

.. code-block:: python

  cert1 = lief.PE.x509.parse("ca1.crt")
  cert2 = lief.PE.x509.parse("ca2.crt")

  print(signer.cert.is_trusted_by([cert1, cert2]))


Limitations
~~~~~~~~~~~

Regarding the PKCS #7 structure itself, LIEF is able to parse and process most of its elements. Nevertheless,
the :class:`lief.PE.SignerInfo` structure can embed attributes (authenticated or not) whose the ASN.1 structure
can be public or not. As of LIEF v0.11.0 we do not support yet the following OIDs:

+----------------------------+-------------------------------------------------------+
| OID                        | Description                                           |
+============================+=======================================================+
| 1.3.6.1.4.1.311.3.3.1      | Ms-CounterSign (undocumented)                         |
+----------------------------+-------------------------------------------------------+
| 1.2.840.113549.1.9.16.2.12 | S/MIME Signing certificate (id-aa-signingCertificate) |
+----------------------------+-------------------------------------------------------+
| 1.3.6.1.4.1.311.2.6.1      | SPC_COMMERCIAL_SP_KEY_PURPOSE_OBJID                   |
+----------------------------+-------------------------------------------------------+
| 1.3.6.1.4.1.311.10.3.28    | szOID_PLATFORM_MANIFEST_BINARY_ID                     |
+----------------------------+-------------------------------------------------------+

These not-supported attributes are wrapped within the :class:`lief.PE.GenericType` that exposes the raw
ASN.1 blob with the property :attr:`~lief.PE.GenericType.raw_content`.

Conclusion
~~~~~~~~~~

Under the hood, most of the work is done by `mbedtls <https://github.com/ARMmbed/mbedtls>`_ which provides the following primitive used
by LIEF:

- ASN.1 decoder
- x509 certificate processing (parsing AND verification)
- Hash algorithms
- Public key algorithms

For the *fun*, we can also cross-compile a small C++ snippet for iOS:

.. code-block:: cpp

   #include <LIEF/PE.hpp>

   int main(int argc, char** argv) {
     std::unique_ptr<LIEF::PE::Binary> pe = LIEF::PE::Parser::parse(argv[1])
     if (pe->verify_signature() == LIEF::PE::Signature::VERIFICATION_FLAGS.OK) {
       std::cout << "Signature ok!" << "\n";
       return 0;
     }
     std::cout << "Error!" << "\n";
     return 1;
   }

So that we can verify the integrity of a PE executable on an iPhone:

.. code-block:: console

  iPhone:~ root# file PE32_x86-64_binary_avast-free-antivirus-setup-online.exe
  PE32_x86-64_binary_avast-free-antivirus-setup-online.exe: PE32 executable (GUI) Intel 80386, for MS Windows
  iPhone:~ root# file ./pe_authenticode_check
  ./pe_authenticode_check: Mach-O 64-bit arm64 executable, flags:<NOUNDEFS|DYLDLINK|TWOLEVEL|WEAK_DEFINES|BINDS_TO_WEAK|PIE|HAS_TLV_DESCRIPTORS>
  iPhone:~ root# ./pe_authenticode_check PE32_x86-64_binary_avast-free-antivirus-setup-online.exe
  Signature ok!
  iPhone:~ root#

Whilst this example is quite useless, it emphasizes the purpose of this project:

- Provide a cross-platform and cross-format library
- Expose a high-level API (Python) as well as a (more or less) low-level API (C++)
- Few dependencies so that the static version of LIEF does not need external libraries [#]_.

..  code-block:: console

   $ otool -L pe_authenticode_check

   /System/Library/Frameworks/Foundation.framework/Foundation (compatibility version 300.0.0, current version 1770.255.0)
   /usr/lib/libobjc.A.dylib (compatibility version 1.0.0, current version 228.0.0)
   /usr/lib/libc++.1.dylib (compatibility version 1.0.0, current version 904.4.0)
   /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1292.60.1)


To complete these functionalities of LIEF, you might also be interested in the following projects
that deal with Authenticode:

+------------------+----------------------------------------------+
| Project          | URL                                          |
+==================+==============================================+
| signify          | https://github.com/ralphje/signify           |
+------------------+----------------------------------------------+
| winsign          | https://github.com/mozilla-releng/winsign    |
+------------------+----------------------------------------------+
| uthenticode      | https://github.com/trailofbits/uthenticode   |
+------------------+----------------------------------------------+
| AuthenticodeLint | https://github.com/vcsjones/AuthenticodeLint |
+------------------+----------------------------------------------+
| osslsigncode     | https://github.com/mtrojnar/osslsigncode     |
+------------------+----------------------------------------------+

Finally, you can find additional information about the Authenticode in Trail of Bits blog post [#]_.
If you are interested in Authenticode tricks used by Dropbox, you can take a look at Microsoft website [#]_ and
if you are interested in understanding how the integrity of the PKCS #7 works, you can look at *Manual verify PKCS#7 signed data with OpenSSL* [#]_


.. rubric:: References

.. [#] http://download.microsoft.com/download/9/c/5/9c5b2167-8017-4bae-9fde-d599bac8184a/Authenticode_PE.docx

.. [#] Which now exceptions-free

.. [#] This tutorial uses the Python API but the C++ API is very similar

.. [#] See: `src/PE/signature/Signature.cpp - check() <https://github.com/lief-project/LIEF/tree/master/src/PE/signature/Signature.cpp>`_ for the implementation

.. [#] Except the C/C++ STL

.. [#] https://blog.trailofbits.com/2020/05/27/verifying-windows-binaries-without-windows/

.. [#] https://docs.microsoft.com/en-us/archive/blogs/ieinternals/caveats-for-authenticode-code-signing

.. [#] http://qistoph.blogspot.com/2012/01/manual-verify-pkcs7-signed-data-with.html



.. rubric:: API

* :meth:`lief.PE.Binary.verify_signature`
* :meth:`lief.PE.Binary.authentihash`
* :attr:`lief.PE.Binary.authentihash_md5`
* :attr:`lief.PE.Binary.authentihash_sha1`
* :attr:`lief.PE.Binary.authentihash_sha256`
* :attr:`lief.PE.Binary.authentihash_sha512`
* :attr:`lief.PE.Binary.signatures`

* :class:`lief.PE.Signature`
* :class:`lief.PE.x509`
* :class:`lief.PE.ContentInfo`
* :class:`lief.PE.SignerInfo`
* :class:`lief.PE.Attribute`
* :class:`lief.PE.ContentType`
* :class:`lief.PE.GenericType`
* :class:`lief.PE.MsSpcNestedSignature`
* :class:`lief.PE.MsSpcStatementType`
* :class:`lief.PE.PKCS9AtSequenceNumber`
* :class:`lief.PE.PKCS9CounterSignature`
* :class:`lief.PE.PKCS9MessageDigest`
* :class:`lief.PE.PKCS9SigningTime`
* :class:`lief.PE.SpcSpOpusInfo`

