使用 Django 发送 S/MIME 签名邮件

Question

有没有办法使用 Django 提供的包装器来发送签名甚至加密的电子邮件？
我们公司使用 S/MIME，要求所有邮件都经过签名。
我目前通过 SendGrid 发送电子邮件：

EMAIL_HOST = 'smtp.sendgrid.net'
EMAIL_HOST_USER = 'apikey'
EMAIL_HOST_PASSWORD = "<email_password>"
EMAIL_PORT = 587
EMAIL_USE_TLS = True

Answer 1

很有趣，我这周刚接到同样的任务，来到这里希望你或其他成员找到解决方案:)

我使用包M2Crypto 提取了这个，基本上它只是改编自包的docs/ 文件夹中提供的this example。

请注意，在我的情况下，我将 Cipher 更改为 aes_256_cbc，并且发送的电子邮件需要签名和加密，否则由于某些标头问题，我无法在 Outlook 客户端中解密这些邮件。

from M2Crypto import BIO, SMIME, X509
import smtplib
from django.conf import settings

def sendsmime(from_addr, to_addrs, subject, msg, from_key, from_cert=None, to_certs=None):
    msg_bio = BIO.MemoryBuffer(msg)
    sign = from_key
    encrypt = to_certs

    s = SMIME.SMIME()
    if sign:
        s.load_key(from_key, from_cert)
        if encrypt:
            p7 = s.sign(msg_bio, flags=SMIME.PKCS7_TEXT)
        else:
            p7 = s.sign(msg_bio, flags=SMIME.PKCS7_TEXT | SMIME.PKCS7_DETACHED)
        msg_bio = BIO.MemoryBuffer(msg)  # Recreate coz sign() has consumed it.

    if encrypt:
        sk = X509.X509_Stack()
        for x in to_certs:
            sk.push(X509.load_cert(x))
        s.set_x509_stack(sk)
        s.set_cipher(SMIME.Cipher('aes_256_cbc'))
        tmp_bio = BIO.MemoryBuffer()
        if sign:
            s.write(tmp_bio, p7)
        else:
            tmp_bio.write(msg)
        p7 = s.encrypt(tmp_bio)

    out = BIO.MemoryBuffer()
    out.write('From: %s\r\n' % from_addr)
    out.write('To: %s\r\n' % ", ".join(to_addrs))
    out.write('Subject: %s\r\n' % subject)
    if encrypt:
        s.write(out, p7)
    else:
        if sign:
            s.write(out, p7, msg_bio, SMIME.PKCS7_TEXT)
        else:
            out.write('\r\n')
            out.write(msg)
    out.close()

    smtp = smtplib.SMTP(settings.EMAIL_HOST, settings.EMAIL_PORT)
    smtp.ehlo()
    smtp.sendmail(from_addr, to_addrs, out.read())
    smtp.quit()