电子邮件加密项目代码

这里提供一个使用Python实现的电子邮件加密项目代码，使用了PGP (Pretty Good Privacy)算法进行加密和解密。

import gnupg
import smtplib
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.mime.application import MIMEApplication

class EmailSender:
    def __init__(self, gpg_passphrase):
        self.gpg = gnupg.GPG()
        self.gpg.passphrase = gpg_passphrase
    
    def _encrypt(self, message, recipient_key):
        encrypted_data = self.gpg.encrypt(message, recipient_key, always_trust=True)
        return str(encrypted_data)
    
    def _send_email(self, sender_email, sender_password, recipient_email, subject, message, attachment=None):
        msg = MIMEMultipart()
        msg['From'] = sender_email
        msg['To'] = recipient_email
        msg['Subject'] = subject

        if attachment:
            with open(attachment, "rb") as f:
                data = f.read()
            part = MIMEApplication(data, Name=attachment)
            part['Content-Disposition'] = 'attachment; filename="%s"' % attachment
            msg.attach(part)

        msg.attach(MIMEText(message, 'plain'))

        server = smtplib.SMTP('smtp.gmail.com', 587)
        server.starttls()
        server.login(sender_email, sender_password)
        server.sendmail(sender_email, recipient_email, msg.as_string())
        server.quit()

    def send_encrypted_email(self, sender_email, sender_password, recipient_email, subject, message, recipient_key, attachment=None):
        encrypted_message = self._encrypt(message, recipient_key)
        self._send_email(sender_email, sender_password, recipient_email, subject, encrypted_message, attachment)

使用方法：

# 初始化 EmailSender
sender = EmailSender(gpg_passphrase='your_gpg_passphrase')

# 发送加密邮件
sender.send_encrypted_email(
    sender_email='your_sender_email@gmail.com',
    sender_password='your_sender_email_password',
    recipient_email='recipient_email@gmail.com',
    subject='Test email',
    message='This is a test email.',
    recipient_key='recipient_public_key',
    attachment='path/to/attachment'
)

请注意：在使用本代码之前，需要安装 gnupg 和 python-gnupg 模块，并且需要先生成密钥对并导入收件人的公钥。