fix(ldap-auth) remove bin.mod and negative cache

- Remove negative caching as there is no way for invalidation
- Use `%` instead of `bin.mod`

kong/plugins/ldap-auth/access.lua

@@ -113,8 +113,7 @@ local function authenticate(conf, given_credentials)
   end
 
   local credential, err = singletons.cache:get(cache_key(conf, given_username), {
-    ttl = conf.cache_ttl,
-    neg_ttl = conf.cache_ttl,
+    ttl = conf.cache_ttl
   }, load_credential, given_username, given_password, conf)
   if err or credential == nil then
     return responses.send_HTTP_INTERNAL_SERVER_ERROR(err)

kong/plugins/ldap-auth/asn1.lua

@@ -8,6 +8,7 @@ local setmetatable = setmetatable
 local table = table
 local string_reverse = string.reverse
 local string_char = string.char
+local pairs = pairs
 
 local _M = {}
 
@@ -271,10 +272,10 @@ _M.ASN1Encoder = {
 
   encode_oid_component = function(n)
     local parts = {}
-    parts[1] = string_char(bit.mod(n, 128))
+    parts[1] = string_char(n % 128)
     while n >= 128 do
       n = bit.rshift(n, 7)
-      parts[#parts + 1] = string_char(bit.mod(n, 128) + 0x80)
+      parts[#parts + 1] = string_char(n % 128 + 0x80)
     end
     return string_reverse(table.concat(parts))
   end,
@@ -319,7 +320,7 @@ _M.ASN1Encoder = {
       local parts = {}
 
       while len > 0 do
-        parts[#parts + 1] = string_char(bit.mod(len, 256))
+        parts[#parts + 1] = string_char(len % 256)
         len = bit.rshift(len, 8)
       end
 

kong/plugins/ldap-auth/ldap.lua

@@ -48,6 +48,8 @@ local function claculate_payload_length(encStr, pos, socket)
 end
 
 function _M.bind_request(socket, username, password)
+  local inspect = require("inspect")
+  print(inspect(username), ":     ", password)
   local encoder = asn1.ASN1Encoder:new()
   local decoder = asn1.ASN1Decoder:new()
 

spec/03-plugins/21-ldap-auth/01-access_spec.lua

@@ -289,6 +289,17 @@ for _, strategy in helpers.each_strategy() do
       })
       assert.response(res).has.status(403)
     end)
+    it("authorization fails with correct status with wrong very long password", function()
+      local res = assert(proxy_client:send {
+        method  = "GET",
+        path    = "/request",
+        headers = {
+          host          = "ldap.com",
+          authorization = "ldap " .. ngx.encode_base64("einstein:e0d91f53c566e0d91f53c566e0d91f53c566e0d91f53c566e0d91f53c566e0d91f53c566e0d91f53c566e0d91f53c566e0d91f53c566e0d91f53c566e0d91f53c566e0d91f53c566e0d91f53c566")
+        }
+      })
+      assert.response(res).has.status(403)
+    end)
     it("authorization fails if credential has multiple encoded usernames or passwords separated by ':' in get request", function()
       local res = assert(proxy_client:send {
         method  = "GET",

spec/03-plugins/21-ldap-auth/02-invalidations_spec.lua

@@ -0,0 +1,122 @@
+local helpers = require "spec.helpers"
+local cjson = require "cjson"
+local fmt = string.format
+local lower = string.lower
+local md5 = ngx.md5
+
+local ldap_host_aws = "ec2-54-172-82-117.compute-1.amazonaws.com"
+
+for _, strategy in helpers.each_strategy() do
+  describe("Plugin: ldap-auth (invalidations) [#" .. strategy .. "]", function()
+    local proxy_client
+    local admin_client
+    local plugin
+
+    setup(function()
+      local bp
+      bp = helpers.get_db_utils(strategy)
+
+      local route = bp.routes:insert {
+        hosts = { "ldapauth.com" },
+      }
+
+      plugin = bp.plugins:insert {
+        route_id = route.id,
+        name     = "ldap-auth",
+        config   = {
+          ldap_host = ldap_host_aws,
+          ldap_port = "389",
+          start_tls = false,
+          base_dn   = "ou=scientists,dc=ldap,dc=mashape,dc=com",
+          attribute = "uid"
+        }
+      }
+
+      assert(helpers.start_kong({
+        database   = strategy,
+        nginx_conf = "spec/fixtures/custom_nginx.template",
+      }))
+
+      proxy_client = helpers.proxy_client()
+      admin_client = helpers.admin_client()
+    end)
+
+    teardown(function()
+      if proxy_client and admin_client then
+        proxy_client:close()
+        admin_client:close()
+      end
+
+      helpers.stop_kong(nil, true)
+    end)
+
+    local function cache_key(conf, username)
+        local ldap_config_cache = md5(fmt("%s:%u:%s:%s:%u",
+          lower(conf.ldap_host),
+          conf.ldap_port,
+          conf.base_dn,
+          conf.attribute,
+          conf.cache_ttl
+        ))
+
+      return fmt("ldap_auth_cache:%s:%s", ldap_config_cache, username)
+    end
+
+    describe("authenticated LDAP user get cached", function()
+      it("should invalidate when Hmac Auth Credential entity is deleted", function()
+        -- It should work
+        local res = assert(proxy_client:send {
+          method = "GET",
+          path = "/requests",
+          body = {},
+          headers = {
+            ["HOST"] = "ldapauth.com",
+            authorization = "ldap " .. ngx.encode_base64("einstein:password")
+          }
+        })
+        assert.res_status(200, res)
+
+        -- Check that cache is populated
+        local cache_key = cache_key(plugin.config, "einstein")
+        res = assert(admin_client:send {
+          method = "GET",
+          path   = "/cache/" .. cache_key,
+          body   = {},
+        })
+        assert.res_status(200, res)
+      end)
+      it("should not do negative cache", function()
+        local res = assert(proxy_client:send {
+          method = "GET",
+          path = "/requests",
+          body = {},
+          headers = {
+            ["HOST"] = "ldapauth.com",
+            authorization = "ldap " .. ngx.encode_base64("einstein:wrongpassword")
+          }
+        })
+        assert.res_status(403, res)
+
+        local cache_key = cache_key(plugin.config, "einstein")
+        res = assert(admin_client:send {
+          method = "GET",
+          path   = "/cache/" .. cache_key,
+          body   = {},
+        })
+        local body = assert.res_status(200, res)
+        assert.is_equal("password", cjson.decode(body).password)
+
+        local res = assert(proxy_client:send {
+          method = "GET",
+          path = "/requests",
+          body = {},
+          headers = {
+            ["HOST"] = "ldapauth.com",
+            authorization = "ldap " .. ngx.encode_base64("einstein:password")
+          }
+        })
+        assert.res_status(200, res)
+      end)
+    end)
+  end)
+end