Implemented SameSite cookie flag, added small bug fix related to #27, and some cleanups, marking this as a Release 2.4.

Author: bungle

CHANGES

@@ -1,3 +1,15 @@
+Changes with lua-resty-session 2.4                               17 Apr 2016
+
+    *) Feature: Cookie will now have SameSite attribute set as "Lax" by
+       default. You can turn it off or set to "Strict" by configuration.
+
+    *) Change: Calling save will not also set session.id if the save
+       was called without calling start first.
+
+       See Also: https://github.com/bungle/lua-resty-session/issues/27
+
+       Thanks @hcaihao
+
 Changes with lua-resty-session 2.3                               16 Oct 2015
 
     *) Bugfix: Fixes issue #19 where regenerating session would

LICENSE

@@ -1,4 +1,4 @@
-Copyright (c) 2014, Aapo Talvensaari
+Copyright (c) 2014 – 2016, Aapo Talvensaari
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without

README.md

@@ -706,6 +706,14 @@ This can be configured with Nginx `set $session_cookie_path /forums/;`.
 Nginx variable `host`. This can be configured with Nginx `set $session_cookie_domain openresty.org;`.
 For `localhost` this is omitted.
 
+#### string session.cookie.samesite
+
+`session.cookie.samesite` holds the value of the cookie SameSite flag. By default we do use value of `Lax`.
+The possible values are `Lax`, `Strict`, and `off`. Actually, setting this parameter anything else than
+`Lax` or `Strict` will turn this off (but in general, you shouldn't do it). If you want better protection
+against Cross Site Requet Forgery (CSRF), set this to `Strict`. Default value of `Lax` gives you quite a
+good protection against CSRF, but `Strict` goes even further.
+
 #### boolean session.cookie.secure
 
 `session.cookie.secure` holds the value of the cookie `Secure` flag. meaning that when set the client will
@@ -830,6 +838,7 @@ set $session_cookie_renew      600;
 set $session_cookie_lifetime   3600;
 set $session_cookie_path       /;
 set $session_cookie_domain     openresty.org;
+set $session_cookie_samesite   Lax;
 set $session_cookie_secure     on;
 set $session_cookie_httponly   on;
 set $session_cookie_delimiter  |;
@@ -850,7 +859,7 @@ set $session_cipher_rounds     1;
 `lua-resty-session` uses two clause BSD license.
 
 ```
-Copyright (c) 2015, Aapo Talvensaari
+Copyright (c) 2014 – 2016 Aapo Talvensaari
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without modification,

lib/resty/session.lua

@@ -1,11 +1,16 @@
-local ngx_var      = ngx.var
-local ngx_header   = ngx.header
+local require      = require
+local var          = ngx.var
+local header       = ngx.header
 local concat       = table.concat
 local hmac         = ngx.hmac_sha1
 local time         = ngx.time
 local http_time    = ngx.http_time
+local find         = string.find
 local type         = type
+local pcall        = pcall
+local tonumber     = tonumber
 local setmetatable = setmetatable
+local getmetatable = getmetatable
 local ffi          = require "ffi"
 local ffi_cdef     = ffi.cdef
 local ffi_new      = ffi.new
@@ -33,50 +38,63 @@ end
 
 local function setcookie(session, value, expires)
     local c = session.cookie
-    local cookie = { session.name, "=", value or "" }
-    local domain = c.domain
+    local i = 3
+    local n = session.name .. "="
+    local k = { n, value or "" }
+    local d = c.domain
     if expires then
-        cookie[#cookie + 1] = "; Expires=Thu, 01 Jan 1970 00:00:01 GMT; Max-Age=0"
+        k[i] = "; Expires=Thu, 01 Jan 1970 00:00:01 GMT; Max-Age=0"
+        i=i+1
     elseif c.persistent then
-        cookie[#cookie + 1] = "; Expires="
-        cookie[#cookie + 1] = http_time(session.expires)
-        cookie[#cookie + 1] = "; Max-Age="
-        cookie[#cookie + 1] = c.lifetime
+        k[i]   = "; Expires="
+        k[i+1] = http_time(session.expires)
+        k[i+2] = "; Max-Age="
+        k[i+3] = c.lifetime
+        i=i+4
     end
-    if domain and domain ~= "localhost" and domain ~= "" then
-        cookie[#cookie + 1] = "; Domain="
-        cookie[#cookie + 1] = domain
+    if d and d ~= "localhost" and d ~= "" then
+        k[i]   = "; Domain="
+        k[i+1] = d
+        i=i+2
+    end
+    k[i]   = "; Path="
+    k[i+1] = c.path or "/"
+    i=i+2
+    if c.samesite == "Lax" or c.samesite == "Strict" then
+        k[i] = "; SameSite="
+        k[i+1] = c.samesite
+        i=i+2
     end
-    cookie[#cookie + 1] = "; Path="
-    cookie[#cookie + 1] = c.path or "/"
     if c.secure then
-        cookie[#cookie + 1] = "; Secure"
+        k[i] = "; Secure"
+        i=i+1
     end
     if c.httponly then
-        cookie[#cookie + 1] = "; HttpOnly"
+        k[i] = "; HttpOnly"
+        i=i+1
     end
-    local needle = concat(cookie, nil, 1, 2)
-    cookie = concat(cookie)
-    local cookies = ngx_header["Set-Cookie"]
-    local t = type(cookies)
+    k = concat(k)
+    local s = header["Set-Cookie"]
+    local t = type(s)
     if t == "table" then
-        local found = false
-        for i, c in ipairs(cookies) do
-            if c:find(needle, 1, true) == 1 then
-                cookies[i] = cookie
-                found = true
+        local f = false
+        local z = #s
+        for i=1, z do
+            if find(s[i], n, 1, true) == 1 then
+                s[i] = k
+                f = true
                 break
             end
         end
-        if not found then
-            cookies[#cookies + 1] = cookie
+        if not f then
+            s[z+1] = k
         end
-    elseif t == "string" and cookies:find(needle, 1, true) ~= 1  then
-        cookies = { cookies, cookie }
+    elseif t == "string" and find(s, n, 1, true) ~= 1  then
+        s = { s, k }
     else
-        cookies = cookie
+        s = k
     end
-    ngx_header["Set-Cookie"] = cookies
+    header["Set-Cookie"] = s
     return true
 end
 
@@ -104,35 +122,36 @@ local function regenerate(session, flush)
     end
 end
 
-local persistent = enabled(ngx_var.session_cookie_persistent or false)
+local persistent = enabled(var.session_cookie_persistent or false)
 local defaults = {
-    name       = ngx_var.session_name       or "session",
-    storage    = ngx_var.session_storage    or "cookie",
-    serializer = ngx_var.session_serializer or "json",
-    encoder    = ngx_var.session_encoder    or "base64",
-    cipher     = ngx_var.session_cipher     or "aes",
+    name       = var.session_name       or "session",
+    storage    = var.session_storage    or "cookie",
+    serializer = var.session_serializer or "json",
+    encoder    = var.session_encoder    or "base64",
+    cipher     = var.session_cipher     or "aes",
     cookie = {
         persistent = persistent,
-        renew      = tonumber(ngx_var.session_cookie_renew)    or 600,
-        lifetime   = tonumber(ngx_var.session_cookie_lifetime) or 3600,
-        path       = ngx_var.session_cookie_path               or "/",
-        domain     = ngx_var.session_cookie_domain,
-        secure     = enabled(ngx_var.session_cookie_secure),
-        httponly   = enabled(ngx_var.session_cookie_httponly   or true),
-        delimiter  = ngx_var.session_cookie_delimiter          or "|"
+        renew      = tonumber(var.session_cookie_renew)    or 600,
+        lifetime   = tonumber(var.session_cookie_lifetime) or 3600,
+        path       = var.session_cookie_path               or "/",
+        domain     = var.session_cookie_domain,
+        secure     = enabled(var.session_cookie_secure),
+        httponly   = enabled(var.session_cookie_httponly   or true),
+        samesite   = var.session_cookie_samesite           or "Lax",
+        delimiter  = var.session_cookie_delimiter          or "|"
     }, check = {
-        ssi    = enabled(ngx_var.session_check_ssi    or persistent == false),
-        ua     = enabled(ngx_var.session_check_ua     or true),
-        scheme = enabled(ngx_var.session_check_scheme or true),
-        addr   = enabled(ngx_var.session_check_addr   or false)
+        ssi    = enabled(var.session_check_ssi    or persistent == false),
+        ua     = enabled(var.session_check_ua     or true),
+        scheme = enabled(var.session_check_scheme or true),
+        addr   = enabled(var.session_check_addr   or false)
     }, identifier = {
-        length  = tonumber(ngx_var.session_identifier_length) or 16
+        length  = tonumber(var.session_identifier_length) or 16
     }
 }
-defaults.secret = ngx_var.session_secret or random(32)
+defaults.secret = var.session_secret or random(32)
 
 local session = {
-    _VERSION = "2.2"
+    _VERSION = "2.3-dev"
 }
 
 session.__index = session
@@ -177,6 +196,7 @@ function session.new(opts)
             domain     = a.domain     or b.domain,
             secure     = a.secure     or b.secure,
             httponly   = a.httponly   or b.httponly,
+            samesite   = a.samesite   or b.samesite,
             delimiter  = a.delimiter  or b.delimiter
         }, check = {
             ssi        = c.ssi        or d.ssi,
@@ -201,43 +221,43 @@ function session.open(opts)
     else
         self = session.new(opts)
     end
-    local scheme = ngx_header["X-Forwarded-Proto"]
+    local scheme = header["X-Forwarded-Proto"]
     if self.cookie.secure == nil then
         if scheme then
             self.cookie.secure = scheme == "https"
         else
-            self.cookie.secure = ngx_var.https == "on"
+            self.cookie.secure = var.https == "on"
         end
     end
-    scheme = self.check.scheme and (scheme or ngx_var.scheme or "") or ""
+    scheme = self.check.scheme and (scheme or var.scheme or "") or ""
     local addr = ""
     if self.check.addr then
-        addr = ngx_header["CF-Connecting-IP"] or
-               ngx_header["Fastly-Client-IP"] or
-               ngx_header["Incap-Client-IP"]  or
-               ngx_header["X-Real-IP"]
+        addr = header["CF-Connecting-IP"] or
+               header["Fastly-Client-IP"] or
+               header["Incap-Client-IP"]  or
+               header["X-Real-IP"]
         if not addr then
-            addr = ngx_header["X-Forwarded-For"]
+            addr = header["X-Forwarded-For"]
             if addr then
                 -- We shouldn't really get the left-most address, because of spoofing,
                 -- but this is better handled with a module, like nginx realip module,
                 -- anyway (see also: http://goo.gl/Z6u2oR).
-                local s = (addr:find(',', 1, true))
+                local s = find(addr, ',', 1, true)
                 if s then
                     addr = addr:sub(1, s - 1)
                 end
             else
-                addr = ngx_var.remote_addr
+                addr = var.remote_addr
             end
         end
     end
     self.key = concat{
-        self.check.ssi and (ngx_var.ssl_session_id  or "") or "",
-        self.check.ua  and (ngx_var.http_user_agent or "") or "",
+        self.check.ssi and (var.ssl_session_id  or "") or "",
+        self.check.ua  and (var.http_user_agent or "") or "",
         addr,
         scheme
     }
-    local cookie = ngx_var["cookie_" .. self.name]
+    local cookie = var["cookie_" .. self.name]
     if cookie then
         local i, e, d, h = self.storage:open(cookie, self.cookie.lifetime)
         if i and e and e > time() and d and h then
@@ -283,8 +303,11 @@ function session:regenerate(flush)
     return save(self)
 end
 
-function session:save()
-    return save(self, true)
+function session:save(close)
+    if not self.id then
+        self.id = random(self.identifier.length)
+    end
+    return save(self, close)
 end
 
 function session:destroy()

lib/resty/session/ciphers/aes.lua

@@ -3,7 +3,7 @@ local tonumber     = tonumber
 local aes          = require "resty.aes"
 local cip          = aes.cipher
 local hashes       = aes.hash
-local ngx_var      = ngx.var
+local var          = ngx.var
 
 local CIPHER_MODES = {
     ecb    = "ecb",
@@ -22,10 +22,10 @@ local CIPHER_SIZES = {
 }
 
 local defaults = {
-    size   = CIPHER_SIZES[ngx_var.session_aes_size] or 256,
-    mode   = CIPHER_MODES[ngx_var.session_aes_mode] or "cbc",
-    hash   = hashes[ngx_var.session_aes_hash]       or "sha512",
-    rounds = tonumber(ngx_var.session_aes_rounds)   or 1
+    size   = CIPHER_SIZES[var.session_aes_size] or 256,
+    mode   = CIPHER_MODES[var.session_aes_mode] or "cbc",
+    hash   = hashes[var.session_aes_hash]       or "sha512",
+    rounds = tonumber(var.session_aes_rounds)   or 1
 }
 
 local cipher = {}
@@ -35,10 +35,10 @@ cipher.__index = cipher
 function cipher.new(config)
     local a = config.aes or defaults
     return setmetatable({
-        size   = CIPHER_MODES[a.size or defaults.size] or 256,
-        mode   = CIPHER_MODES[a.mode or defaults.mode] or "cbc",
-        hash   = hashes[a.hash or defaults.hash]       or hashes.sha512,
-        rounds = tonumber(a.rounds or defaults.rounds) or 1
+        size   = CIPHER_MODES[a.size or defaults.size]   or 256,
+        mode   = CIPHER_MODES[a.mode or defaults.mode]   or "cbc",
+        hash   = hashes[a.hash       or defaults.hash]   or hashes.sha512,
+        rounds = tonumber(a.rounds   or defaults.rounds) or 1
     }, cipher)
 end
 

lib/resty/session/encoders/base64.lua

@@ -1,5 +1,6 @@
-local base64enc   = ngx.encode_base64
-local base64dec   = ngx.decode_base64
+local ngx       = ngx
+local base64enc = ngx.encode_base64
+local base64dec = ngx.decode_base64
 
 local ENCODE_CHARS = {
     ["+"] = "-",

lib/resty/session/storage/memcache.lua

@@ -5,23 +5,24 @@ local concat       = table.concat
 local floor        = math.floor
 local sleep        = ngx.sleep
 local now          = ngx.now
+local var          = ngx.var
 
 local function enabled(val)
     if val == nil then return nil end
     return val == true or (val == "1" or val == "true" or val == "on")
 end
 
 local defaults = {
-    prefix       = ngx.var.session_memcache_prefix or "sessions",
-    socket       = ngx.var.session_memcache_socket,
-    host         = ngx.var.session_memcache_host or "127.0.0.1",
-    port         = tonumber(ngx.var.session_memcache_port) or 11211,
-    uselocking   = enabled(ngx.var.session_memcache_uselocking or true),
-    spinlockwait = tonumber(ngx.var.session_memcache_spinlockwait) or 10000,
-    maxlockwait  = tonumber(ngx.var.session_memcache_maxlockwait) or 30,
+    prefix       = var.session_memcache_prefix                 or "sessions",
+    socket       = var.session_memcache_socket,
+    host         = var.session_memcache_host                   or "127.0.0.1",
+    port         = tonumber(var.session_memcache_port)         or 11211,
+    uselocking   = enabled(var.session_memcache_uselocking     or true),
+    spinlockwait = tonumber(var.session_memcache_spinlockwait) or 10000,
+    maxlockwait  = tonumber(var.session_memcache_maxlockwait)  or 30,
     pool = {
-        timeout  = tonumber(ngx.var.session_memcache_pool_timeout),
-        size     = tonumber(ngx.var.session_memcache_pool_size)
+        timeout  = tonumber(var.session_memcache_pool_timeout),
+        size     = tonumber(var.session_memcache_pool_size)
     }
 }