fix: escape login and password when passed from dovecot to doveauth

This should allow to use / in the password

chatmaild/src/chatmaild/doveauth.py

@@ -98,6 +98,32 @@ def lookup_passdb(db, config: Config, user, cleartext_password):
         )
 
 
+def split_and_unescape(s):
+    """Split strings using double quote as a separator and backslash as escape character
+    into parts."""
+
+    out = ""
+    i = 0
+    while i < len(s):
+        c = s[i]
+        if c == "\\":
+            # Skip escape character.
+            i += 1
+
+            # This will raise IndexError if there is no character
+            # after escape character. This is expected
+            # as this is an invalid input.
+            out += s[i]
+        elif c == '"':
+            # Separator
+            yield out
+            out = ""
+        else:
+            out += c
+        i += 1
+    yield out
+
+
 def handle_dovecot_request(msg, db, config: Config):
     short_command = msg[0]
     if short_command == "L":  # LOOKUP
@@ -107,7 +133,9 @@ def handle_dovecot_request(msg, db, config: Config):
         # do not attempt to read any other parts for compatibility.
         keyname = parts[0]
 
-        namespace, type, *args = keyname.split("/")
+        namespace, type, args = keyname.split("/", 2)
+        args = list(split_and_unescape(args))
+
         reply_command = "F"
         res = ""
         if namespace == "shared":

chatmaild/src/chatmaild/tests/test_doveauth.py

@@ -52,8 +52,9 @@ def test_too_high_db_version(db):
 
 
 def test_handle_dovecot_request(db, example_config):
+    # Test that password can contain ", ', \ and /
     msg = (
-        "Lshared/passdb/laksjdlaksjdlaksjdlk12j3l1k2j3123/"
+        'Lshared/passdb/laksjdlaksjdlak\\\\sjdlk\\"12j\\\'3l1/k2j3123"'
         "some42123@chat.example.org\tsome42123@chat.example.org"
     )
     res = handle_dovecot_request(msg, db, example_config)

cmdeploy/src/cmdeploy/dovecot/auth.conf

@@ -1,5 +1,10 @@
 uri = proxy:/run/dovecot/doveauth.socket:auth
 iterate_disable = yes
 default_pass_scheme = plain
-password_key = passdb/%w/%u
+# %E escapes characters " (double quote), ' (single quote) and \ (backslash) with \ (backslash).
-user_key = userdb/%u
+# See <https://doc.dovecot.org/configuration_manual/config_file/config_variables/#modifiers>
+# for documentation.
+#
+# We escape user-provided input and use double quote as a separator.
+password_key = passdb/%Ew"%Eu
+user_key = userdb/%Eu