Merge pull request #1133 from Mashape/plugins/ldap

LDAP plugin

kong-0.8.0rc2-0.rockspec

@@ -13,6 +13,7 @@ description = {
 dependencies = {
   "luasec ~> 0.5-2",
 
+  "penlight ~> 1.3.2",
   "lua_uuid ~> 0.2.0-2",
   "lua_system_constants ~> 0.1.1-0",
   "luatz ~> 0.3-1",
@@ -33,7 +34,8 @@ dependencies = {
   "lrexlib-pcre ~> 2.7.2-1",
   "lua-llthreads2 ~> 0.1.3-1",
   "luacrypto >= 0.3.2-1",
-  "luasyslog >= 1.0.0-2"
+  "luasyslog >= 1.0.0-2",
+  "lua_pack ~> 1.0.4-0"
 }
 build = {
   type = "builtin",
@@ -247,6 +249,12 @@ build = {
     ["kong.plugins.hmac-auth.api"] = "kong/plugins/hmac-auth/api.lua",
     ["kong.plugins.hmac-auth.daos"] = "kong/plugins/hmac-auth/daos.lua",
 
+    ["kong.plugins.ldap-auth.handler"] = "kong/plugins/ldap-auth/handler.lua",
+    ["kong.plugins.ldap-auth.access"] = "kong/plugins/ldap-auth/access.lua",
+    ["kong.plugins.ldap-auth.schema"] = "kong/plugins/ldap-auth/schema.lua",
+    ["kong.plugins.ldap-auth.ldap"] = "kong/plugins/ldap-auth/ldap.lua",
+    ["kong.plugins.ldap-auth.asn1"] = "kong/plugins/ldap-auth/asn1.lua",
+
     ["kong.plugins.syslog.handler"] = "kong/plugins/syslog/handler.lua",
     ["kong.plugins.syslog.schema"] = "kong/plugins/syslog/schema.lua",
 

kong/constants.lua

@@ -18,7 +18,7 @@ return {
     "http-log", "key-auth", "hmac-auth", "basic-auth", "ip-restriction",
     "mashape-analytics", "request-transformer", "response-transformer",
     "request-size-limiting", "rate-limiting", "response-ratelimiting", "syslog",
-    "loggly", "datadog", "runscope"
+    "loggly", "datadog", "runscope", "ldap-auth"
   },
   -- Non standard headers, specific to Kong
   HEADERS = {

kong/plugins/ldap-auth/access.lua

@@ -0,0 +1,114 @@
+local responses = require "kong.tools.responses"
+local constants = require "kong.constants"
+local cache = require "kong.tools.database_cache"
+local base64 = require "base64"
+local ldap = require "kong.plugins.ldap-auth.ldap"
+
+local match = string.match
+local ngx_log = ngx.log
+local request = ngx.req
+local ngx_error = ngx.ERR
+local ngx_debug = ngx.DEBUG
+local ngx_socket_tcp = ngx.socket.tcp
+local tostring =  tostring
+
+local AUTHORIZATION = "authorization"
+local PROXY_AUTHORIZATION = "proxy-authorization"
+
+local _M = {}
+
+local function retrieve_credentials(authorization_header_value, conf)
+  local username, password
+  if authorization_header_value then
+    local cred = match(authorization_header_value, "%s*[ldap|LDAP]%s+(.*)")
+
+    if cred ~= nil then
+      local decoded_cred = base64.decode(cred)
+      username, password = match(decoded_cred, "(.+):(.+)")
+    end
+  end
+  return username, password
+end
+
+local function ldap_authenticate(given_username, given_password, conf)
+  local is_authenticated
+  local error, suppressed_err, ok
+  local who = conf.attribute.."="..given_username..","..conf.base_dn
+
+  local sock = ngx_socket_tcp()
+  sock:settimeout(conf.timeout)
+  ok, error = sock:connect(conf.ldap_host, conf.ldap_port)
+  if not ok then
+    ngx_log(ngx_error, "[ldap-auth] failed to connect to "..conf.ldap_host..":"..tostring(conf.ldap_port)..": ", error)
+    return responses.send_HTTP_INTERNAL_SERVER_ERROR(error)
+  end
+
+  if conf.start_tls then
+    local success, error = ldap.start_tls(sock)
+    if not success then
+      return false, error
+    end
+    local _, error = sock:sslhandshake(true, conf.ldap_host, conf.verify_ldap_host)
+    if error ~= nil then
+      return false, "failed to do SSL handshake with "..conf.ldap_host..":"..tostring(conf.ldap_port)..": ".. error
+    end
+  end
+
+  is_authenticated, error = ldap.bind_request(sock, who, given_password)
+
+  ok, suppressed_err = sock:setkeepalive(conf.keepalive)
+  if not ok then
+    ngx_log(ngx_error, "[ldap-auth] failed to keepalive to "..conf.ldap_host..":"..tostring(conf.ldap_port)..": ", suppressed_err)
+  end
+  return is_authenticated, error
+end
+
+local function authenticate(conf, given_credentials)
+  local given_username, given_password = retrieve_credentials(given_credentials)
+  if given_username == nil then
+    return false
+  end
+
+  local credential = cache.get_or_set(cache.ldap_credential_key(given_username), function()
+    ngx_log(ngx_debug, "[ldap-auth] authenticating user against LDAP server: "..conf.ldap_host..":"..conf.ldap_port)
+
+    local ok, err = ldap_authenticate(given_username, given_password, conf)
+    if err ~= nil then ngx_log(ngx_error, err) end
+    if not ok then
+      return nil
+    end
+    return {username = given_username, password = given_password}
+  end, conf.cache_ttl)
+
+  return credential and credential.password == given_password, credential
+end
+
+function _M.execute(conf)
+  local authorization_value = request.get_headers()[AUTHORIZATION]
+  local proxy_authorization_value = request.get_headers()[PROXY_AUTHORIZATION]
+
+  -- If both headers are missing, return 401
+  if not (authorization_value or proxy_authorization_value) then
+    ngx.header["WWW-Authenticate"] = 'LDAP realm="kong"'
+    return responses.send_HTTP_UNAUTHORIZED()
+  end
+
+  local is_authorized, credential = authenticate(conf, proxy_authorization_value)
+  if not is_authorized then
+    is_authorized, credential = authenticate(conf, authorization_value)
+  end
+
+  if not is_authorized then
+    return responses.send_HTTP_FORBIDDEN("Invalid authentication credentials")
+  end
+
+  if conf.hide_credentials then
+    request.clear_header(AUTHORIZATION)
+    request.clear_header(PROXY_AUTHORIZATION)
+  end
+
+  request.set_header(constants.HEADERS.CREDENTIAL_USERNAME, credential.username)
+  ngx.ctx.authenticated_credential = credential
+end
+
+return _M