[Feature] Add controller endpoint to get fuzzy hashes from messages

Sample usage:

```
curl -XPOST 'http://localhost:11334/plugins/fuzzy/hashes?flag=1' --data-binary '@-' < file
```

Sample output:
```json
{
  "hashes": {
    "local": [
      "24b6e7de2f489778d828c827079c48bacb086f816d0a7acabbe42e8d0da703b89b913176ad67eefaf5b54fa59f5e0ecfc7015846c4043fcfb0c7a4ed7a235025",
      "72789777cbec926f4143de4c08c87acc3fbf3b909b5c39f1edcf82ed12e2d8bc2f56be8d68ee681feccf44ca04e3eca5b8ec039cb84a0d40e22258c370a10cbb"
    ],
    "rspamd.com": [
      "24b6e7de2f489778d828c827079c48bacb086f816d0a7acabbe42e8d0da703b89b913176ad67eefaf5b54fa59f5e0ecfc7015846c4043fcfb0c7a4ed7a235025",
      "72789777cbec926f4143de4c08c87acc3fbf3b909b5c39f1edcf82ed12e2d8bc2f56be8d68ee681feccf44ca04e3eca5b8ec039cb84a0d40e22258c370a10cbb"
    ],
  },
  "success": true
}
```

Issue: #4489

2 files changed, 47 insertions, 0 deletions

diff --git a/rules/controller/fuzzy.lua b/rules/controller/fuzzy.lua
new file mode 100644
index 000000000..7e4c96fe1
--- /dev/null
+++ b/rules/controller/fuzzy.lua
@@ -0,0 +1,46 @@
+--[[
+Copyright (c) 2023, Vsevolod Stakhov <vsevolod@rspamd.com>
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+]]--
+
+local function handle_gen_fuzzy(task, conn, req_params)
+  if type(rspamd_plugins.fuzzy_check) == 'table' then
+    local ret, hashes
+    task:process_message()
+    if req_params.rule then
+      ret,hashes = pcall(rspamd_plugins.fuzzy_check.hex_hashes, task, req_params.rule)
+    elseif req_params.flag then
+      ret,hashes = pcall(rspamd_plugins.fuzzy_check.hex_hashes, task, tonumber(req_params.flag))
+    else
+      conn:send_error(404, 'missing rule or flag')
+      return
+    end
+
+    if ret then
+      conn:send_ucl({success = true, hashes = hashes})
+    else
+      conn:send_error(500, 'cannot generate hashes')
+    end
+  else
+    conn:send_error(404, 'fuzzy_check is not enabled')
+  end
+end
+
+return {
+  hashes = {
+    handler = handle_gen_fuzzy,
+    need_task = true,
+    enable = false
+  },
+}
\ No newline at end of file
diff --git a/rules/controller/init.lua b/rules/controller/init.lua
index 90bb137c4..9d60200f8 100644
--- a/rules/controller/init.lua
+++ b/rules/controller/init.lua
@@ -28,6 +28,7 @@ local controller_plugin_paths = {
   maps = dofile(local_rules .. "/controller/maps.lua"),
   neural = dofile(local_rules .. "/controller/neural.lua"),
   selectors = dofile(local_rules .. "/controller/selectors.lua"),
+  fuzzy = dofile(local_rules .. "/controller/fuzzy.lua"),
 }
 
 if rspamd_util.file_exists(local_conf .. '/controller.lua') then