new: Support email forwarding

fake_smtp.py

@@ -1,5 +1,4 @@
 #!/usr/bin/env python
-import sys
 import ssl
 from pathlib import Path
 import importlib
@@ -9,11 +8,11 @@ from aiosmtpd.smtp import SMTP
 import subprocess
 import argparse
 
-key_path = Path('certs', 'key.pem')
-cert_path = Path('certs', 'cert.pem')
-
 
 def get_context():
+    key_path = Path('certs', 'key.pem')
+    cert_path = Path('certs', 'cert.pem')
+
     if not cert_path.exists() and not key_path.exists():
         subprocess.call(f'openssl req -x509 -newkey rsa:4096 -keyout {key_path.as_posix()} -out {cert_path.as_posix()} -days 365 -nodes -subj "/CN=localhost"', shell=True)
 
@@ -39,7 +38,10 @@ class CustomSMTPHandler:
         print(f'Message addressed from: {envelope.mail_from}')
         print(f'Message addressed to  : {envelope.rcpt_tos}')
         print(f'Message length        : {len(envelope.content)}')
-        p = run([binpath, "-"], stdout=PIPE, input=envelope.content)
+        if email_forward in envelope.rcpt_tos:
+            p = run([binpath_forward, "-"], stdout=PIPE, input=envelope.content)
+        else:
+            p = run([binpath, "-"], stdout=PIPE, input=envelope.content)
         print(p)
         return '250 OK'
 
@@ -47,25 +49,26 @@ class CustomSMTPHandler:
 if __name__ == '__main__':
     parser = argparse.ArgumentParser(description='Launch a fake SMTP server to push SPAMs to a MISP instance')
     parser.add_argument("--path", default='./mail_to_misp.py', help="Path to the mail_to_misp.py script.")
+    parser.add_argument("--path_forward", default='./mail_to_misp.py', help="Path to the mail_to_misp.py script.")
+    parser.add_argument("--email_forward", default='mail2misp@example.com', help="Path to the mail_to_misp.py script.")
     parser.add_argument("--host", default='127.0.0.1', help="IP to attach the SMTP server to.")
     parser.add_argument("--port", default='2525', help="Port of the SMTP server")
     parser.add_argument("--ssl", action='store_true', help="Pure SMTPs.")
     args = parser.parse_args()
 
-    if not args.path and not args.host and not args.port and not args.ssl:
-        configmodule = Path(__file__).as_posix().replace('.py', '_config')
-        if Path(f'{configmodule}.py').exists():
-            config = importlib.import_module(configmodule)
-        else:
-            print("Couldn't locate config file {0}".format(f'{configmodule}.py'))
-            sys.exit(-1)
-
+    configmodule = Path(__file__).as_posix().replace('.py', '_config')
+    if Path(f'{configmodule}.py').exists():
+        config = importlib.import_module(configmodule)
         binpath = config.binpath
+        binpath_forward = config.binpath_forward
+        email_forward = config.email_forward
         smtp_addr = config.smtp_addr
         smtp_port = config.smtp_port
         smtps = config.ssl
     else:
         binpath = args.path
+        binpath_forward = args.path_forward
+        email_forward = args.email_forward
         smtp_addr = args.host
         smtp_port = args.port
         smtps = args.ssl

fake_smtp_config.py-example

@@ -2,7 +2,10 @@
 # -*- coding: utf-8 -*-
 from pathlib import Path
 
-binpath = Path(__file__).cwd() / 'mail_to_misp.py'
+binpath = Path(__file__).parent / 'mail_to_misp.py'
+binpath_forward = Path(__file__).parent / 'mail_to_misp_forward.py'
+
+forward_email = 'mail2misp@example.com'
 
 smtp_addr = '127.0.0.1'
 smtp_port = 2525

mail_to_misp_forward.py

@@ -0,0 +1 @@
+mail_to_misp.py