gnome-sendmail.py

gnome-sendmail.py

#! /usr/bin/env python3
#
# SPDX-License-Identifier: GPL-3.0-or-later
#
# Command line access to GNOME Online Accounts mail accounts
#
# Authors:
#     Daniel P. Berrange <[email protected]>
#     Paolo Bonzini <[email protected]>

import argparse
import base64
import smtplib
import sys
import json
import gi

gi.require_version("Gio", "2.0")
from gi.repository import GLib
from gi.repository import Gio

GOA_BUS_NAME = "org.gnome.OnlineAccounts"
GOA_BUS_PATH = "/org/gnome/OnlineAccounts"

GOA_ACCT_IFACE = "org.gnome.OnlineAccounts.Account"
GOA_MAIL_IFACE = "org.gnome.OnlineAccounts.Mail"
GOA_OAUTH2_IFACE = "org.gnome.OnlineAccounts.OAuth2Based"
GOA_PASSWORD_IFACE = "org.gnome.OnlineAccounts.PasswordBased"


def goa_dbus_proxy(path, iface):
    return Gio.DBusProxy.new_for_bus_sync(
        Gio.BusType.SESSION,
        Gio.DBusProxyFlags.NONE,
        None,
        GOA_BUS_NAME,
        path,
        iface,
        None,
    )


class GOAMailAccount:
    def __init__(self, obj_path, obj_ifaces):
        self.obj_path = obj_path
        self.obj_ifaces = obj_ifaces

    @property
    def path(self):
        return obj_path

    @property
    def can_authenticate(self):
        return (
            GOA_OAUTH2_IFACE in self.obj_ifaces or GOA_PASSWORD_IFACE in self.obj_ifaces
        )

    @property
    def identity(self):
        return self.obj_ifaces[GOA_ACCT_IFACE]["Identity"]

    @property
    def is_oauth2(self):
        return GOA_OAUTH2_IFACE in self.obj_ifaces

    @property
    def oauth2_access_token(self):
        if GOA_OAUTH2_IFACE not in self.obj_ifaces:
            raise Exception("not an OAuth2 account")

        mgr = goa_dbus_proxy(self.obj_path, GOA_OAUTH2_IFACE)
        token = mgr.call_sync("GetAccessToken", None, Gio.DBusCallFlags.NONE, -1, None)
        return token.unpack()[0]

    def auth_oauthbearer(self, challenge=None):
        if GOA_OAUTH2_IFACE not in self.obj_ifaces:
            raise Exception("not an OAuth2 account")

        a = "\001"
        token = self.oauth2_access_token
        return f"n,a={self.smtp_user},{a}host={self.smtp_host}{a}port={self.smtp_port}{a}auth=Bearer {token}{a}{a}"

    @property
    def smtp_password(self):
        if GOA_PASSWORD_IFACE not in self.obj_ifaces:
            raise Exception("not a password-based account")

        mgr = goa_dbus_proxy(self.obj_path, GOA_PASSWORD_IFACE)
        arg = GLib.Variant.new_string("smtp-password")
        args = GLib.Variant.new_tuple(arg)
        password = mgr.call_sync("GetPassword", args, Gio.DBusCallFlags.NONE, -1, None)
        return password.unpack()[0]

    @property
    def smtp_host(self):
        return self.obj_ifaces[GOA_MAIL_IFACE]["SmtpHost"]

    @property
    def smtp_user(self):
        return self.obj_ifaces[GOA_MAIL_IFACE]["SmtpUserName"]

    @property
    def smtp_port(self):
        if self.obj_ifaces[GOA_MAIL_IFACE]["SmtpUseSsl"]:
            return 465
        if self.obj_ifaces[GOA_MAIL_IFACE]["SmtpUseTls"]:
            return 587
        return 25

    def smtp_login(self):
        if not self.obj_ifaces[GOA_MAIL_IFACE]["SmtpSupported"]:
            raise Exception("SMTP not supported for this account")

        if self.obj_ifaces[GOA_MAIL_IFACE]["SmtpUseSsl"]:
            smtp = smtplib.SMTP_SSL(self.smtp_host, self.smtp_port)
        else:
            smtp = smtplib.SMTP(self.smtp_host, self.smtp_port)
            if self.obj_ifaces[GOA_MAIL_IFACE]["SmtpUseTls"]:
                smtp.ehlo()
                smtp.starttls()

        smtp.ehlo()

        if GOA_OAUTH2_IFACE in self.obj_ifaces:
            smtp.auth("OAUTHBEARER", self.auth_oauthbearer)
            return smtp

        if GOA_PASSWORD_IFACE in self.obj_ifaces:
            smtp.login(self.smtp_user, self.smtp_password)
            return smtp

        raise Exception("do not know how to login")


def find_mail_account_objs():
    mgr = goa_dbus_proxy(GOA_BUS_PATH, "org.freedesktop.DBus.ObjectManager")
    accts = mgr.call_sync("GetManagedObjects", None, Gio.DBusCallFlags.NONE, -1, None)
    acct_objs = accts.unpack()[0]

    return [
        GOAMailAccount(obj_path, obj_ifaces)
        for obj_path, obj_ifaces in acct_objs.items()
        if GOA_ACCT_IFACE in obj_ifaces and GOA_MAIL_IFACE in obj_ifaces
    ]


def list_mail_identities():
    for obj in find_mail_account_objs():
        if obj.can_authenticate:
            print(obj.identity)


def get_mail_account_obj(identity):
    for obj in find_mail_account_objs():
        if obj.identity == identity:
            return obj
    return None


def main():
    parser = argparse.ArgumentParser(
        formatter_class=argparse.RawDescriptionHelpFormatter,
        description="""Command line access to GNOME Online Accounts mail accounts.""",
        epilog="""
If invoked with a username as the sole argument, print the SMTP
password or the OAUTH2 authentication token.

If invoked with -f and -i arguments send email from the given
email address to the recipients, similar to /usr/bin/sendmail.
The -f argument is required in order to send email; if you are
using 'git send-email', please add:\n
    [sendemail]
    envelopesender = auto\n
to your git configuration""",
    )
    parser.add_argument(
        "username",
        metavar="USERNAME",
        nargs="?",
        help="Retrieve password or token for the user",
    )
    parser.add_argument(
        "-f",
        dest="sender",
        metavar="SENDER",
        help="Sender of the message"
    )
    parser.add_argument(
        "-i",
        dest="recipients",
        metavar="RECIPIENT",
        nargs="+",
        help="Recipient of the message",
    )
    args = parser.parse_args()

    if not args.sender and args.recipients:
        print("The -f argument is required in order to send email.", file=sys.stderr)
        print("If you are using 'git send-email', please add:\n", file=sys.stderr)
        print("    [sendemail]", file=sys.stderr)
        print("    envelopesender = auto\n", file=sys.stderr)
        print("to your git configuration", file=sys.stderr)
        sys.exit(1)

    if args.sender and args.username:
        print(f"Cannot specify a username together with -f.", file=sys.stderr)
        sys.exit(1)

    identity = args.username or args.sender
    if not identity:
        list_mail_identities()
        sys.exit(0)

    gmail_obj = get_mail_account_obj(identity)
    if gmail_obj is None:
        print(f"No GNOME account found for {identity} with Mail", file=sys.stderr)
        sys.exit(1)

    if args.username:
        if gmail_obj.is_oauth2:
            print(gmail_obj.oauth2_access_token)
        else:
            print(gmail_obj.smtp_password)
    else:
        smtp = gmail_obj.smtp_login()
        msg = b"\r\n".join(sys.stdin.buffer.read().splitlines())
        smtp.sendmail(args.sender, args.recipients, msg)


if __name__ == "__main__":
    main()