Authenticate echobot by passing /run/echobot/password to doveauth

chatmaild/src/chatmaild/doveauth.py

@@ -4,6 +4,7 @@ import time
 import sys
 import json
 import crypt
+from pathlib import Path
 from socketserver import (
     UnixStreamServer,
     StreamRequestHandler,
@@ -86,11 +87,18 @@ def lookup_userdb(db, config: Config, user):
 
 def lookup_passdb(db, config: Config, user, cleartext_password):
     if user == f"echo@{config.mail_domain}":
+        # Echobot writes password it wants to log in with into /run/echobot/password
+        try:
+            password = Path("/run/echobot/password").read_text()
+        except Exception:
+            logging.exception("Exception when trying to read /run/echobot/password")
+            return None
+
         return dict(
             home=f"/home/vmail/mail/{config.mail_domain}/echo@{config.mail_domain}",
             uid="vmail",
             gid="vmail",
-            password=encrypt_password("eiPhiez0eo8raighoh0C"),  # FIXME read from config
+            password=encrypt_password(password),
         )
 
     with db.write_transaction() as conn:

chatmaild/src/chatmaild/echo.py

@@ -7,10 +7,13 @@ it will echo back any message that has non-empty text and also supports the /hel
 import logging
 import os
 import sys
+import subprocess
 
 from deltachat_rpc_client import Bot, DeltaChat, EventType, Rpc, events
+from pathlib import Path
 
 from chatmaild.config import read_config
+from chatmaild.newemail import create_newemail_dict
 
 hooks = events.HookCollection()
 
@@ -75,9 +78,23 @@ def main():
         account = accounts[0] if accounts else deltachat.add_account()
 
         bot = Bot(account, hooks)
+
+        config = read_config(sys.argv[1])
+
+        # Create password file
+        if bot.is_configured():
+            password = bot.account.get_config("mail_pw")
+        else:
+            password = create_newemail_dict(config)["password"]
+        Path("/run/echobot/password").write_text(password)
+
+        # Give the user which doveauth runs as access to the password file.
+        subprocess.run(
+            ["/usr/bin/setfacl", "-m", "user:vmail:r", "/run/echobot/password"],
+            check=True,
+        )
+
         if not bot.is_configured():
-            config = read_config(sys.argv[1])
-            password = "eiPhiez0eo8raighoh0C"  # FIXME read from config
             email = "echo@" + config.mail_domain
             bot.configure(email, password)
         bot.run_forever()

cmdeploy/src/cmdeploy/service/echobot.service.f

@@ -13,6 +13,12 @@ Group=echobot
 # Create /var/lib/echobot
 StateDirectory=echobot
 
+# Create /run/echobot
+#
+# echobot stores /run/echobot/password
+# with a password there, which doveauth then reads.
+RuntimeDirectory=echobot
+
 WorkingDirectory=/var/lib/echobot
 
 # Apply security restrictions suggested by
@@ -24,7 +30,10 @@ NoNewPrivileges=true
 PrivateDevices=true
 PrivateMounts=true
 PrivateTmp=true
-PrivateUsers=true
+
+# We need to know about doveauth user to give it access to /run/echobot/password
+PrivateUsers=false
+
 ProtectClock=true
 ProtectControlGroups=true
 ProtectHostname=true