Added spoofed email test

app/email/headers.py

@@ -13,6 +13,7 @@ MIME_VERSION = "Mime-Version"
 REPLY_TO = "Reply-To"
 RECEIVED = "Received"
 RSPAM_QUEUE_ID = "X-Rspamd-Queue-Id"
+SPAMD_RESULT = "X-Spamd-Result"
 CC = "Cc"
 DKIM_SIGNATURE = "DKIM-Signature"
 X_SPAM_STATUS = "X-Spam-Status"

email_handler.py

@@ -536,6 +536,55 @@ def handle_email_sent_to_ourself(alias, from_addr: str, msg: Message, user):
     )
 
 
+def apply_dmarc_policy(alias: Alias, contact: Contact, msg: Message) -> Optional[str]:
+    spam_result = msg.get_all(headers.SPAMD_RESULT)
+    if not spam_result:
+        return False
+    spam_entries = [entry.strip() for entry in spam_result[-1].split("\n")]
+    for iPos in range(len(spam_entries)):
+        sep = spam_entries[iPos].find("(")
+        if sep > -1:
+            spam_entries[iPos] = spam_entries[iPos][:sep]
+    if "DMARC_POLICY_REJECT" in spam_entries:
+        return status.E519
+    if (
+        "DMARC_POLICY_SOFTFAIL" in spam_entries
+        or "DMARC_POLICY_QUARANTINE" in spam_entries
+    ):
+        add_or_replace_header(msg, headers.SL_DIRECTION, "Forward")
+        msg[headers.SL_ENVELOPE_TO] = alias.email
+        add_or_replace_header(msg, "From", contact.new_addr())
+        # replace CC & To emails by reverse-alias for all emails that are not alias
+        try:
+            replace_header_when_forward(msg, alias, "Cc")
+            replace_header_when_forward(msg, alias, "To")
+        except CannotCreateContactForReverseAlias:
+            Session.commit()
+            raise
+
+        random_name = str(uuid.uuid4())
+        s3_report_path = f"refused-emails/full-{random_name}.eml"
+        s3.upload_email_from_bytesio(
+            s3_report_path, BytesIO(to_bytes(msg)), f"full-{random_name}"
+        )
+        refused_email = RefusedEmail.create(
+            full_report_path=s3_report_path, user_id=alias.user_id, flush=True
+        )
+        EmailLog.create(
+            user_id=alias.user_id,
+            mailbox_id=alias.mailbox_id,
+            contact_id=contact.id,
+            alias_id=alias.id,
+            message_id=str(msg[headers.MESSAGE_ID]),
+            refused_email_id=refused_email.id,
+            is_spam=True,
+            blocked=True,
+            commit=True,
+        )
+        return status.E519
+    return None
+
+
 def handle_forward(envelope, msg: Message, rcpt_to: str) -> List[Tuple[bool, str]]:
     """return an array of SMTP status (is_success, smtp_status)
     is_success indicates whether an email has been delivered and
@@ -616,6 +665,11 @@ def handle_forward(envelope, msg: Message, rcpt_to: str) -> List[Tuple[bool, str
         # do not return 5** to allow user to receive emails later when alias is enabled or contact is unblocked
         return [(True, res_status)]
 
+    # Check if we need to reject or quarantine based on dmarc
+    dmarc_delivery_status = apply_dmarc_policy(alias, contact, msg)
+    if dmarc_delivery_status is not None:
+        return [(False, dmarc_delivery_status)]
+
     ret = []
     mailboxes = alias.mailboxes
 

tests/api/test_serializer.py

@@ -2,7 +2,7 @@ from app.api.serializer import get_alias_infos_with_pagination_v3
 from app.config import PAGE_LIMIT
 from app.db import Session
 from app.models import User, Alias, Mailbox, Contact
-from tests.utils import create_user
+from tests.utils import create_random_user
 
 
 def test_get_alias_infos_with_pagination_v3(flask_client):
@@ -147,7 +147,7 @@ def test_get_alias_infos_with_pagination_v3_no_duplicate_when_empty_contact(
     """
     Make sure an alias is returned once when it has 2 contacts that have no email log activity
     """
-    user = create_user(flask_client)
+    user = create_random_user()
     alias = Alias.first()
 
     Contact.create(

tests/example_emls/gmail_spoof.eml

@@ -8,7 +8,7 @@ Received: from relay.somewhere.net (relay.somewhere.net [34.59.200.130])
         by mx1.sldev.ovh (Postfix) with ESMTPS id 6D8C13F069
         for <wehrman_mannequin@sldev.ovh>; Thu, 17 Mar 2022 16:50:20 +0000 (UTC)
 Date: Thu, 17 Mar 2022 16:50:18 +0000
-To: wehrman_mannequin@sldev.ovh
+To: {{ alias_email }}
 From: spoofedemailsource@gmail.com
 Subject: test Thu, 17 Mar 2022 16:50:18 +0000
 Message-Id: <20220317165018.000191@somewhere-5488dd4b6b-7crp6>

tests/test_email_handler.py

@@ -2,14 +2,17 @@ import email
 import os.path
 from email.message import EmailMessage
 
-from app.email import headers
-from app.models import User, Alias, AuthorizedAddress, IgnoredEmail
+from aiosmtpd.smtp import Envelope
+
+import email_handler
+from app.email import headers, status
+from app.models import User, Alias, AuthorizedAddress, IgnoredEmail, EmailLog
 from email_handler import (
     get_mailbox_from_mail_from,
     should_ignore,
     is_automatic_out_of_office,
 )
-from tests.utils import load_eml_file
+from tests.utils import load_eml_file, create_random_user, create_random_alias
 
 
 def test_get_mailbox_from_mail_from(flask_client):
@@ -66,9 +69,21 @@ def test_is_automatic_out_of_office():
     assert is_automatic_out_of_office(msg)
 
 
-def test_process_spoofed():
-    msg = load_eml_file("gmail_spoof.eml")
-    breakpoint()
-    a = msg["a"]
-    b = 1
-    c = 2
+def test_process_spoofed(flask_client):
+    user = create_random_user()
+    alias = create_random_alias(user)
+    msg = load_eml_file("gmail_spoof.eml", {"alias_email": alias.email})
+    envelope = Envelope()
+    envelope.mail_from = msg["from"]
+    envelope.rcpt_tos = [msg["to"]]
+    result = email_handler.handle(envelope, msg)
+    assert result == status.E519
+    email_logs = (
+        EmailLog.filter_by(user_id=user.id, alias_id=alias.id)
+        .order_by(EmailLog.id.desc())
+        .all()
+    )
+    assert len(email_logs) == 1
+    email_log = email_logs[0]
+    assert email_log.blocked
+    assert email_log.refused_email_id

tests/utils.py

@@ -1,11 +1,14 @@
 import email
 import json
 import os
+import random
+import string
 from email.message import EmailMessage
 
+import jinja2
 from flask import url_for
 
-from app.models import User
+from app.models import User, Alias
 
 
 def login(flask_client) -> User:
@@ -30,10 +33,14 @@ def login(flask_client) -> User:
     return user
 
 
-def create_user(flask_client) -> User:
-    # create user, user is activated
+def random_token(length: int = 10) -> str:
+    return "".join(random.choices(string.ascii_lowercase + string.digits, k=length))
+
+
+def create_random_user() -> User:
+    email = "{}@{}.com".format(random_token(), random_token())
     return User.create(
-        email="a@b.c",
+        email=email,
         password="password",
         name="Test User",
         activated=True,
@@ -41,14 +48,27 @@ def create_user(flask_client) -> User:
     )
 
 
+def create_random_alias(user: User) -> Alias:
+    alias_email = "{}@{}.com".format(random_token(), random_token())
+    alias = Alias.create(
+        user_id=user.id,
+        email=alias_email,
+        mailbox_id=user.default_mailbox_id,
+        commit=True,
+    )
+    return alias
+
+
 def pretty(d):
     """pretty print as json"""
     print(json.dumps(d, indent=2))
 
 
-def load_eml_file(filename: str) -> EmailMessage:
+def load_eml_file(filename: str, template_values={}) -> EmailMessage:
     emails_dir = os.path.join(
         os.path.dirname(os.path.realpath(__file__)), "example_emls"
     )
     fullpath = os.path.join(emails_dir, filename)
-    return email.message_from_file(open(fullpath))
+    template = jinja2.Template(open(fullpath).read())
+    rendered = template.render(**template_values)
+    return email.message_from_string(rendered)