From 59c2434bf31778e07a83c93260f9fdb99d9e4a4b Mon Sep 17 00:00:00 2001
From: Israel Figueroa <israel.figueroa@usm.cl>
Date: Sat, 16 Jul 2022 00:00:13 -0400
Subject: [PATCH] DKIM Support v1

---
 docker-compose.yml         |  1 +
 mayordomo/__init__.py      | 21 ++++++++++++++++++++-
 mayordomo/requirements.txt |  1 +
 3 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/docker-compose.yml b/docker-compose.yml
index 3170373..b3097d6 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -32,6 +32,7 @@ services:
     restart: unless-stopped
     environment:
       - DEBUG=False
+      - DKIM_PRIVKEY=myPricKey.pem
       - DNS_RELAY=192.168.0.1
 #      - DNS_RELAY=200.1.21.80
       - SQLALCHEMY_DATABASE_URI=postgresql+asyncpg://docker:docker@db/docker
diff --git a/mayordomo/__init__.py b/mayordomo/__init__.py
index f61ef73..6a23657 100644
--- a/mayordomo/__init__.py
+++ b/mayordomo/__init__.py
@@ -6,6 +6,9 @@ import sys
 import os
 import aiosmtplib
 import traceback
+import dkim
+from email.parser import Parser
+from email.policy import default
 from aiosmtpd.controller import Controller
 from sqlalchemy.future import select
 from .model import db, update_mx, update_a, FQDN, MXRecord, ARecord, IPV4Addr, Direccion, Destinatario, Carta
@@ -17,6 +20,7 @@ from .resolver import updateDNS
 
 smtprelayport = '10025'
 bindip = '0.0.0.0'
+dkimKey = None
 
 # cacerts = '/etc/ssl/certs/ca-certificates.crt'
 # keyfile = '/var/run/secrets/keyfile'
@@ -27,6 +31,12 @@ if not os.environ.get('SMTP_HOSTNAME'):
 else:
 	banner_hostname = os.environ.get('SMTP_HOSTNAME')
 
+if os.environ.get('DKIM_PRIVKEY'):
+	try:
+		dkimKey = open(os.environ.get('DKIM_PRIVKEY'), 'r').read()
+	except:
+		pass
+
 
 async def enviarCorreosDominio(dominioid):
 	valido = int(time.time())
@@ -117,7 +127,16 @@ async def enviarCorreosDominio(dominioid):
 						
 					await log.info("Carta Rte '{}' => Destinatarios '{}' ".format(remitente.direccion, ', '.join(rcpt_to)))
 					try:
-						await smtp.sendmail(remitente.direccion, rcpt_to, carta.contenido.encode('utf-8'))
+						
+						if dkimKey is not None:							
+							mail2send = Parser(policy=default).parsestr(carta.contenido)						
+							mail2send['DKIM-Signature'] = dkim.sign(carta.contenido, b'mayordomo', b'ilab.cl', dkimKey, include_headers=[b'from', b'to', b'subject', b'message-id']).decode()[len("DKIM-Signature: "):]
+							
+							await smtp.sendmail(remitente.direccion, rcpt_to, mail2send.encode('utf-8'))
+							
+						else:	
+							await smtp.sendmail(remitente.direccion, rcpt_to, carta.contenido.encode('utf-8'))
+						
 						for destinatario in rdest.scalars():
 							destinatario.enviado = 1
 						
diff --git a/mayordomo/requirements.txt b/mayordomo/requirements.txt
index b2129e7..b47bdd5 100644
--- a/mayordomo/requirements.txt
+++ b/mayordomo/requirements.txt
@@ -6,3 +6,4 @@ asyncpg
 python-daemon
 async_dns
 aiosmtplib
+dkimpy
\ No newline at end of file