25.3.8 Backport of #86633 - Add support for user names in config containing a dot

src/Access/UsersConfigAccessStorage.cpp

@@ -115,16 +115,20 @@ namespace
 
     UserPtr parseUser(
         const Poco::Util::AbstractConfiguration & config,
-        const String & user_name,
+        String user_name,
         const std::unordered_set<UUID> & allowed_profile_ids,
         const std::unordered_set<UUID> & allowed_role_ids,
         bool allow_no_password,
         bool allow_plaintext_password)
     {
         const bool validate = true;
         auto user = std::make_shared<User>();
-        user->setName(user_name);
         String user_config = "users." + user_name;
+
+        /// If the user name contains a dot, it is escaped with a backslash when parsed from the config file.
+        /// We need to remove the backslash to get the correct user name.
+        Poco::replaceInPlace(user_name, "\\.", ".");
+        user->setName(user_name);
         bool has_no_password = config.has(user_config + ".no_password");
         bool has_password_plaintext = config.has(user_config + ".password");
         bool has_password_sha256_hex = config.has(user_config + ".password_sha256_hex");

tests/integration/test_dot_in_user_name/configs/users.xml

@@ -0,0 +1,23 @@
+<clickhouse>
+    <users>
+        <default>
+            <password/>
+            <networks>
+                <ip>::/0</ip>
+            </networks>
+            <profile>default</profile>
+            <quota>default</quota>
+        </default>
+        <user.name>
+            <password/>
+            <networks>
+                <ip>::/0</ip>
+            </networks>
+            <profile>default</profile>
+            <quota>default</quota>
+        </user.name>
+    </users>
+    <quotas>
+        <default/>
+    </quotas>
+</clickhouse>

tests/integration/test_dot_in_user_name/test.py

@@ -0,0 +1,35 @@
+import pytest
+
+from helpers.cluster import ClickHouseCluster
+
+cluster = ClickHouseCluster(__file__)
+node = cluster.add_instance(
+    "node",
+    user_configs=[
+        "configs/users.xml",
+    ],
+)
+
+
+@pytest.fixture(scope="module", autouse=True)
+def started_cluster():
+    try:
+        cluster.start()
+        yield cluster
+    finally:
+        cluster.shutdown()
+
+
+def test_user_with_dot_in_name():
+    assert node.query("SELECT count()>0 FROM system.users where name = 'user.name'") == "1\n"
+    assert node.query("SELECT count()>0 FROM system.users where name = 'user\\.name'") == "0\n"
+
+    node.query("DROP USER IF EXISTS 'foo.bar'")
+    node.query("CREATE USER 'foo.bar'")
+    assert node.query("SELECT count()>0 FROM system.users where name = 'foo.bar'") == "1\n"
+    assert node.query("SELECT count()>0 FROM system.users where name = 'foo\\.bar'") == "0\n"
+
+    node.query("ALTER USER 'foo.bar' RENAME TO 'foo\\.bar'")
+    assert node.query("SELECT count()>0 FROM system.users where name = 'foo.bar'") == "0\n"
+    assert node.query("SELECT count()>0 FROM system.users where name = 'foo\\.bar'") == "1\n"
+    node.query("DROP USER 'foo\\.bar'")