Django发送带有数字签名的电子邮件

Question

我正在尝试使用经过加密签名的Django发送电子邮件。它应该是这样的：

我不知道如何获得签名值：

signature = str(gpg.sign(basetext, detach=True))
# Now signature is None.

完整代码：

    body = """
        This is the original message text.

        :)
        """

    basemsg = MIMEText(body)

    gpg = gnupg.GPG()
    basetext = basemsg.as_string().replace('\n', '\r\n')
    signature = str(gpg.sign(basetext, detach=True))
    if signature:
        signmsg = messageFromSignature(signature)
        msg = MIMEMultipart(_subtype="signed", micalg="pgp-sha1",
                            protocol="application/pgp-signature")
        msg.attach(basemsg)
        msg.attach(signmsg)
        print(msg.as_string(unixfrom=True))
    else:
        print('Warning: failed to sign the message!')

Answer 1

正如我的评论所述，gnupg库有两个版本：一个被废弃，一个被维护。使用正确的python-gnupg时，将测试以下代码是否正常工作：

from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart
from email.message import Message
import gnupg
import os


def messageFromSignature(signature):
    message = Message()
    message["Content-Type"] = 'application/pgp-signature; name="signature.asc"'
    message["Content-Description"] = "OpenPGP digital signature"
    message.set_payload(signature)
    return message


def signed_mail():
    body = """
        This is the original message text.

        :)
        """

    basemsg = MIMEText(body)
    gnupghome = os.path.join(os.getenv('HOME', '/homeless'), '.gnupg')

    gpg = gnupg.GPG(gnupghome=gnupghome, use_agent=True)
    basetext = basemsg.as_string().replace("\n", "\r\n")
    signature = str(gpg.sign(basetext, detach=True))
    if signature:
        signmsg = messageFromSignature(signature)
        msg = MIMEMultipart(
            _subtype="signed", micalg="pgp-sha1", protocol="application/pgp-signature"
        )
        msg.attach(basemsg)
        msg.attach(signmsg)
        print(msg.as_string(unixfrom=True))
    else:
        print("Warning: failed to sign the message!")


if __name__ == "__main__":
    signed_mail()

输出：

From nobody Fri Jul 24 19:41:07 2020
Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="===============7347302325830204740=="
MIME-Version: 1.0

--===============7347302325830204740==
Content-Type: text/plain; charset="us-ascii"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit


        This is the original message text.

        :)
        
--===============7347302325830204740==
Content-Type: application/pgp-signature; name="signature.asc"
Content-Description: OpenPGP digital signature

-----BEGIN PGP SIGNATURE-----

iHUEABEIAB0WIQQ7CPtOD4MLM1EdL8f8hi+zE9fGuAUCXxsdMwAKCRD8hi+zE9fG
uN6xAP46c05XTvo4tccCmGRABqjYQRXHHBMuUXqDbv8pmru2igEAmxO53cJkSmEh
+tr+0uHOt2ERB/eiSc+8+2x+9s+6Dmk=
=HRAe
-----END PGP SIGNATURE-----

--===============7347302325830204740==--