Merge pull request #147 from pusher/session-store

Add initial session-store interface and implementation
2019-05-20 10:18:47 +01:00 · 2019-05-20 10:18:47 +01:00 · 17e97ab884
parent a1130e41a3 4ad4b11411
commit 17e97ab884
38 changed files with 985 additions and 137 deletions
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@ -10,7 +10,11 @@

 ## Changes since v3.2.0

- [#114](https://github.com/pusher/oauth2_proxy/pull/114), [#154](https://github.com/pusher/oauth2_proxy/pull/154) Documentation is now available live at our [docs website](https://pusher.github.io/oauth2_proxy/) (@JoelSpeed, @icelynjennings) 
+- [#147](https://github.com/pusher/outh2_proxy/pull/147) Add SessionStore interfaces and initial implementation (@JoelSpeed)
+  - Allows for multiple different session storage implementations including client and server side
+  - Adds tests suite for interface to ensure consistency across implementations
+  - Refactor some configuration options (around cookies) into packages
+- [#114](https://github.com/pusher/oauth2_proxy/pull/114), [#154](https://github.com/pusher/oauth2_proxy/pull/154) Documentation is now available live at our [docs website](https://pusher.github.io/oauth2_proxy/) (@JoelSpeed, @icelynjennings)
 - [#146](https://github.com/pusher/oauth2_proxy/pull/146) Use full email address as `User` if the auth response did not contain a `User` field (@gargath)
 - [#144](https://github.com/pusher/oauth2_proxy/pull/144) Use GO 1.12 for ARM builds (@kskewes)
 - [#142](https://github.com/pusher/oauth2_proxy/pull/142) ARM Docker USER fix (@kskewes)
--- a/Gopkg.lock
+++ b/Gopkg.lock
@ -57,6 +57,20 @@
  pruneopts = ""
  revision = "1e59b77b52bf8e4b449a57e6f79f21226d571845"

+[[projects]]
+  digest = "1:b3c5b95e56c06f5aa72cb2500e6ee5f44fcd122872d4fec2023a488e561218bc"
+  name = "github.com/hpcloud/tail"
+  packages = [
+    ".",
+    "ratelimiter",
+    "util",
+    "watch",
+    "winfile",
+  ]
+  pruneopts = ""
+  revision = "a30252cb686a21eb2d0b98132633053ec2f7f1e5"
+  version = "v1.0.0"
+
 [[projects]]
  digest = "1:af67386ca553c04c6222f7b5b2f17bc97a5dfb3b81b706882c7fd8c72c30cf8f"
  name = "github.com/mbland/hmacauth"
@ -73,6 +87,54 @@
  pruneopts = ""
  revision = "20ba7d382d05facb01e02eb777af0c5f229c5c95"

+[[projects]]
+  digest = "1:a3735b0978a8b53fc2ac97a6f46ca1189f0712a00df86d6ec4cf26c1a25e6d77"
+  name = "github.com/onsi/ginkgo"
+  packages = [
+    ".",
+    "config",
+    "internal/codelocation",
+    "internal/containernode",
+    "internal/failer",
+    "internal/leafnodes",
+    "internal/remote",
+    "internal/spec",
+    "internal/spec_iterator",
+    "internal/specrunner",
+    "internal/suite",
+    "internal/testingtproxy",
+    "internal/writer",
+    "reporters",
+    "reporters/stenographer",
+    "reporters/stenographer/support/go-colorable",
+    "reporters/stenographer/support/go-isatty",
+    "types",
+  ]
+  pruneopts = ""
+  revision = "eea6ad008b96acdaa524f5b409513bf062b500ad"
+  version = "v1.8.0"
+
+[[projects]]
+  digest = "1:dbafce2fddb1ca331646fe2ac9c9413980368b19a60a4406a6e5861680bd73be"
+  name = "github.com/onsi/gomega"
+  packages = [
+    ".",
+    "format",
+    "internal/assertion",
+    "internal/asyncassertion",
+    "internal/oraclematcher",
+    "internal/testingtsupport",
+    "matchers",
+    "matchers/support/goraph/bipartitegraph",
+    "matchers/support/goraph/edge",
+    "matchers/support/goraph/node",
+    "matchers/support/goraph/util",
+    "types",
+  ]
+  pruneopts = ""
+  revision = "90e289841c1ed79b7a598a7cd9959750cb5e89e2"
+  version = "v1.5.0"
+
 [[projects]]
  digest = "1:256484dbbcd271f9ecebc6795b2df8cad4c458dd0f5fd82a8c2fa0c29f233411"
  name = "github.com/pmezard/go-difflib"
@ -131,6 +193,9 @@
  packages = [
    "context",
    "context/ctxhttp",
+    "html",
+    "html/atom",
+    "html/charset",
    "websocket",
  ]
  pruneopts = ""
@ -150,6 +215,42 @@
  pruneopts = ""
  revision = "9ff8ebcc8e241d46f52ecc5bff0e5a2f2dbef402"

+[[projects]]
+  branch = "master"
+  digest = "1:67a6e61e60283fd7dce50eba228080bff8805d9d69b2f121d7ec2260d120c4a8"
+  name = "golang.org/x/sys"
+  packages = ["unix"]
+  pruneopts = ""
+  revision = "ca7f33d4116e3a1f9425755d6a44e7ed9b4c97df"
+
+[[projects]]
+  digest = "1:740b51a55815493a8d0f2b1e0d0ae48fe48953bf7eaf3fcc4198823bf67768c0"
+  name = "golang.org/x/text"
+  packages = [
+    "encoding",
+    "encoding/charmap",
+    "encoding/htmlindex",
+    "encoding/internal",
+    "encoding/internal/identifier",
+    "encoding/japanese",
+    "encoding/korean",
+    "encoding/simplifiedchinese",
+    "encoding/traditionalchinese",
+    "encoding/unicode",
+    "internal/gen",
+    "internal/language",
+    "internal/language/compact",
+    "internal/tag",
+    "internal/utf8internal",
+    "language",
+    "runes",
+    "transform",
+    "unicode/cldr",
+  ]
+  pruneopts = ""
+  revision = "342b2e1fbaa52c93f31447ad2c6abc048c63e475"
+  version = "v0.3.2"
+
 [[projects]]
  branch = "master"
  digest = "1:dc1fb726dbbe79c86369941eae1e3b431b8fc6f11dbd37f7899dc758a43cc3ed"
@ -182,6 +283,15 @@
  revision = "150dc57a1b433e64154302bdc40b6bb8aefa313a"
  version = "v1.0.0"

+[[projects]]
+  digest = "1:eb53021a8aa3f599d29c7102e65026242bdedce998a54837dc67f14b6a97c5fd"
+  name = "gopkg.in/fsnotify.v1"
+  packages = ["."]
+  pruneopts = ""
+  revision = "c2828203cd70a50dcccfb2761f8b1f8ceef9a8e9"
+  source = "https://github.com/fsnotify/fsnotify.git"
+  version = "v1.4.7"
+
 [[projects]]
  digest = "1:cb5b2a45a3dd41c01ff779c54ae4c8aab0271d6d3b3f734c8a8bd2c890299ef2"
  name = "gopkg.in/fsnotify/fsnotify.v1"
@ -210,6 +320,22 @@
  revision = "f8f38de21b4dcd69d0413faf231983f5fd6634b1"
  version = "v2.1.3"

+[[projects]]
+  branch = "v1"
+  digest = "1:a96d16bd088460f2e0685d46c39bcf1208ba46e0a977be2df49864ec7da447dd"
+  name = "gopkg.in/tomb.v1"
+  packages = ["."]
+  pruneopts = ""
+  revision = "dd632973f1e7218eb1089048e0798ec9ae7dceb8"
+
+[[projects]]
+  digest = "1:cedccf16b71e86db87a24f8d4c70b0a855872eb967cb906a66b95de56aefbd0d"
+  name = "gopkg.in/yaml.v2"
+  packages = ["."]
+  pruneopts = ""
+  revision = "51d6538a90f86fe93ac480b35f37b2be17fef232"
+  version = "v2.2.2"
+
 [solve-meta]
  analyzer-name = "dep"
  analyzer-version = 1
@ -220,6 +346,8 @@
    "github.com/dgrijalva/jwt-go",
    "github.com/mbland/hmacauth",
    "github.com/mreiferson/go-options",
+    "github.com/onsi/ginkgo",
+    "github.com/onsi/gomega",
    "github.com/stretchr/testify/assert",
    "github.com/stretchr/testify/require",
    "github.com/yhat/wsutil",
@ -231,6 +359,7 @@
    "google.golang.org/api/googleapi",
    "gopkg.in/fsnotify/fsnotify.v1",
    "gopkg.in/natefinch/lumberjack.v2",
+    "gopkg.in/square/go-jose.v2",
  ]
  solver-name = "gps-cdcl"
  solver-version = 1
--- a/Gopkg.toml
+++ b/Gopkg.toml
@ -35,6 +35,10 @@
  name = "gopkg.in/fsnotify/fsnotify.v1"
  version = "~1.2.0"

+[[override]]
+  name = "gopkg.in/fsnotify.v1"
+  source = "https://github.com/fsnotify/fsnotify.git"
+
 [[constraint]]
  branch = "master"
  name = "golang.org/x/crypto"
--- a/1
+++ b/1
@ -33,6 +33,7 @@ lint: $(GOMETALINTER)
 		--enable=deadcode \
 		--enable=gofmt \
 		--enable=goimports \
+		--deadline=120s \
 		--tests ./...

 .PHONY: dep
--- a/docs/configuration/configuration.md
+++ b/docs/configuration/configuration.md
@ -1,7 +1,8 @@
 ---
 layout: default
 title: Configuration
-permalink: /configuration
+permalink: /docs/configuration
+has_children: true
 nav_order: 3
 ---

@ -78,6 +79,7 @@ Usage of oauth2_proxy:
  -request-logging-format: Template for request log lines (see "Logging Configuration" paragraph below)
  -resource string: The resource that is protected (Azure AD only)
  -scope string: OAuth scope specification
+  -session-store-type: Session data storage backend (default: cookie)
  -set-xauthrequest: set X-Auth-Request-User and X-Auth-Request-Email response headers (useful in Nginx auth_request mode)
  -set-authorization-header: set Authorization Bearer response header (useful in Nginx auth_request mode)
  -signature-key string: GAP-Signature request signature key (algorithm:secretkey)
--- a/docs/configuration/sessions.md
+++ b/docs/configuration/sessions.md
@ -0,0 +1,34 @@
+---
+layout: default
+title: Sessions
+permalink: /configuration
+parent: Configuration
+nav_order: 3
+---
+
+## Sessions
+
+Sessions allow a user's authentication to be tracked between multiple HTTP
+requests to a service.
+
+The OAuth2 Proxy uses a Cookie to track user sessions and will store the session
+data in one of the available session storage backends.
+
+At present the available backends are (as passed to `--session-store-type`):
+- [cookie](cookie-storage) (deafult)
+
+### Cookie Storage
+
+The Cookie storage backend is the default backend implementation and has
+been used in the OAuth2 Proxy historically.
+
+With the Cookie storage backend, all session information is stored in client
+side cookies and transferred with each and every request.
+
+The following should be known when using this implementation:
+- Since all state is stored client side, this storage backend means that the OAuth2 Proxy is completely stateless
+- Cookies are signed server side to prevent modification client-side
+- It is recommended to set a `cookie-secret` which will ensure data is encrypted within the cookie data.
+- Since multiple requests can be made concurrently to the OAuth2 Proxy, this session implementation
+cannot lock sessions and while updating and refreshing sessions, there can be conflicts which force
+users to re-authenticate
--- a/env_options.go
+++ b/env_options.go
@ -15,14 +15,27 @@ type EnvOptions map[string]interface{}
 // Fields in the options struct must have an `env` and `cfg` tag to be read
 // from the environment
 func (cfg EnvOptions) LoadEnvForStruct(options interface{}) {
-	val := reflect.ValueOf(options).Elem()
-	typ := val.Type()
+	val := reflect.ValueOf(options)
+	var typ reflect.Type
+	if val.Kind() == reflect.Ptr {
+		typ = val.Elem().Type()
+	} else {
+		typ = val.Type()
+	}
+
 	for i := 0; i < typ.NumField(); i++ {
 		// pull out the struct tags:
 		//    flag - the name of the command line flag
 		//    deprecated - (optional) the name of the deprecated command line flag
 		//    cfg - (optional, defaults to underscored flag) the name of the config file option
 		field := typ.Field(i)
+		fieldV := reflect.Indirect(val).Field(i)
+
+		if field.Type.Kind() == reflect.Struct && field.Anonymous {
+			cfg.LoadEnvForStruct(fieldV.Interface())
+			continue
+		}
+
 		flagName := field.Tag.Get("flag")
 		envName := field.Tag.Get("env")
 		cfgName := field.Tag.Get("cfg")
--- a/env_options_test.go
+++ b/env_options_test.go
@ -1,26 +1,46 @@
-package main
+package main_test

 import (
 	"os"
 	"testing"

+	proxy "github.com/pusher/oauth2_proxy"
 	"github.com/stretchr/testify/assert"
 )

-type envTest struct {
-	testField string `cfg:"target_field" env:"TEST_ENV_FIELD"`
+type EnvTest struct {
+	TestField string `cfg:"target_field" env:"TEST_ENV_FIELD"`
+	EnvTestEmbed
+}
+
+type EnvTestEmbed struct {
+	TestFieldEmbed string `cfg:"target_field_embed" env:"TEST_ENV_FIELD_EMBED"`
 }

 func TestLoadEnvForStruct(t *testing.T) {

-	cfg := make(EnvOptions)
-	cfg.LoadEnvForStruct(&envTest{})
+	cfg := make(proxy.EnvOptions)
+	cfg.LoadEnvForStruct(&EnvTest{})

 	_, ok := cfg["target_field"]
 	assert.Equal(t, ok, false)

 	os.Setenv("TEST_ENV_FIELD", "1234abcd")
-	cfg.LoadEnvForStruct(&envTest{})
+	cfg.LoadEnvForStruct(&EnvTest{})
 	v := cfg["target_field"]
 	assert.Equal(t, v, "1234abcd")
 }
+
+func TestLoadEnvForStructWithEmbeddedFields(t *testing.T) {
+
+	cfg := make(proxy.EnvOptions)
+	cfg.LoadEnvForStruct(&EnvTest{})
+
+	_, ok := cfg["target_field_embed"]
+	assert.Equal(t, ok, false)
+
+	os.Setenv("TEST_ENV_FIELD_EMBED", "1234abcd")
+	cfg.LoadEnvForStruct(&EnvTest{})
+	v := cfg["target_field_embed"]
+	assert.Equal(t, v, "1234abcd")
+}
--- a/main.go
+++ b/main.go
@ -75,6 +75,8 @@ func main() {
 	flagSet.Bool("cookie-secure", true, "set secure (HTTPS) cookie flag")
 	flagSet.Bool("cookie-httponly", true, "set HttpOnly cookie flag")

+	flagSet.String("session-store-type", "cookie", "the session storage provider to use")
+
 	flagSet.String("logging-filename", "", "File to log requests to, empty for stdout")
 	flagSet.Int("logging-max-size", 100, "Maximum size in megabytes of the log file before rotation")
 	flagSet.Int("logging-max-age", 7, "Maximum number of days to retain old log files")
--- a/oauthproxy.go
+++ b/oauthproxy.go
@ -16,6 +16,7 @@ import (
 	"github.com/mbland/hmacauth"
 	"github.com/pusher/oauth2_proxy/cookie"
 	"github.com/pusher/oauth2_proxy/logger"
+	"github.com/pusher/oauth2_proxy/pkg/apis/sessions"
 	"github.com/pusher/oauth2_proxy/providers"
 	"github.com/yhat/wsutil"
 )
@ -292,7 +293,7 @@ func (p *OAuthProxy) displayCustomLoginForm() bool {
 	return p.HtpasswdFile != nil && p.DisplayHtpasswdForm
 }

-func (p *OAuthProxy) redeemCode(host, code string) (s *providers.SessionState, err error) {
+func (p *OAuthProxy) redeemCode(host, code string) (s *sessions.SessionState, err error) {
 	if code == "" {
 		return nil, errors.New("missing code")
 	}
@ -484,7 +485,7 @@ func (p *OAuthProxy) SetSessionCookie(rw http.ResponseWriter, req *http.Request,
 }

 // LoadCookiedSession reads the user's authentication details from the request
-func (p *OAuthProxy) LoadCookiedSession(req *http.Request) (*providers.SessionState, time.Duration, error) {
+func (p *OAuthProxy) LoadCookiedSession(req *http.Request) (*sessions.SessionState, time.Duration, error) {
 	var age time.Duration
 	c, err := loadCookie(req, p.CookieName)
 	if err != nil {
@ -506,7 +507,7 @@ func (p *OAuthProxy) LoadCookiedSession(req *http.Request) (*providers.SessionSt
 }

 // SaveSession creates a new session cookie value and sets this on the response
-func (p *OAuthProxy) SaveSession(rw http.ResponseWriter, req *http.Request, s *providers.SessionState) error {
+func (p *OAuthProxy) SaveSession(rw http.ResponseWriter, req *http.Request, s *sessions.SessionState) error {
 	value, err := p.provider.CookieForSession(s, p.CookieCipher)
 	if err != nil {
 		return err
@ -693,7 +694,7 @@ func (p *OAuthProxy) SignIn(rw http.ResponseWriter, req *http.Request) {

 	user, ok := p.ManualSignIn(rw, req)
 	if ok {
-		session := &providers.SessionState{User: user}
+		session := &sessions.SessionState{User: user}
 		p.SaveSession(rw, req, session)
 		http.Redirect(rw, req, redirect, 302)
 	} else {
@ -944,7 +945,7 @@ func (p *OAuthProxy) Authenticate(rw http.ResponseWriter, req *http.Request) int

 // CheckBasicAuth checks the requests Authorization header for basic auth
 // credentials and authenticates these against the proxies HtpasswdFile
-func (p *OAuthProxy) CheckBasicAuth(req *http.Request) (*providers.SessionState, error) {
+func (p *OAuthProxy) CheckBasicAuth(req *http.Request) (*sessions.SessionState, error) {
 	if p.HtpasswdFile == nil {
 		return nil, nil
 	}
@ -966,7 +967,7 @@ func (p *OAuthProxy) CheckBasicAuth(req *http.Request) (*providers.SessionState,
 	}
 	if p.HtpasswdFile.Validate(pair[0], pair[1]) {
 		logger.PrintAuthf(pair[0], req, logger.AuthSuccess, "Authenticated via basic auth and HTpasswd File")
-		return &providers.SessionState{User: pair[0]}, nil
+		return &sessions.SessionState{User: pair[0]}, nil
 	}
 	logger.PrintAuthf(pair[0], req, logger.AuthFailure, "Invalid authentication via basic auth: not in Htpasswd File")
 	return nil, nil
--- a/oauthproxy_test.go
+++ b/oauthproxy_test.go
@ -16,6 +16,7 @@ import (

 	"github.com/mbland/hmacauth"
 	"github.com/pusher/oauth2_proxy/logger"
+	"github.com/pusher/oauth2_proxy/pkg/apis/sessions"
 	"github.com/pusher/oauth2_proxy/providers"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@ -253,11 +254,11 @@ func NewTestProvider(providerURL *url.URL, emailAddress string) *TestProvider {
 	}
 }

-func (tp *TestProvider) GetEmailAddress(session *providers.SessionState) (string, error) {
+func (tp *TestProvider) GetEmailAddress(session *sessions.SessionState) (string, error) {
 	return tp.EmailAddress, nil
 }

-func (tp *TestProvider) ValidateSessionState(session *providers.SessionState) bool {
+func (tp *TestProvider) ValidateSessionState(session *sessions.SessionState) bool {
 	return tp.ValidToken
 }

@ -637,7 +638,7 @@ func (p *ProcessCookieTest) MakeCookie(value string, ref time.Time) []*http.Cook
 	return p.proxy.MakeSessionCookie(p.req, value, p.opts.CookieExpire, ref)
 }

-func (p *ProcessCookieTest) SaveSession(s *providers.SessionState, ref time.Time) error {
+func (p *ProcessCookieTest) SaveSession(s *sessions.SessionState, ref time.Time) error {
 	value, err := p.proxy.provider.CookieForSession(s, p.proxy.CookieCipher)
 	if err != nil {
 		return err
@ -648,14 +649,14 @@ func (p *ProcessCookieTest) SaveSession(s *providers.SessionState, ref time.Time
 	return nil
 }

-func (p *ProcessCookieTest) LoadCookiedSession() (*providers.SessionState, time.Duration, error) {
+func (p *ProcessCookieTest) LoadCookiedSession() (*sessions.SessionState, time.Duration, error) {
 	return p.proxy.LoadCookiedSession(p.req)
 }

 func TestLoadCookiedSession(t *testing.T) {
 	pcTest := NewProcessCookieTestWithDefaults()

-	startSession := &providers.SessionState{Email: "john.doe@example.com", AccessToken: "my_access_token"}
+	startSession := &sessions.SessionState{Email: "john.doe@example.com", AccessToken: "my_access_token"}
 	pcTest.SaveSession(startSession, time.Now())

 	session, _, err := pcTest.LoadCookiedSession()
@ -680,7 +681,7 @@ func TestProcessCookieRefreshNotSet(t *testing.T) {
 	pcTest.proxy.CookieExpire = time.Duration(23) * time.Hour
 	reference := time.Now().Add(time.Duration(-2) * time.Hour)

-	startSession := &providers.SessionState{Email: "michael.bland@gsa.gov", AccessToken: "my_access_token"}
+	startSession := &sessions.SessionState{Email: "michael.bland@gsa.gov", AccessToken: "my_access_token"}
 	pcTest.SaveSession(startSession, reference)

 	session, age, err := pcTest.LoadCookiedSession()
@ -695,7 +696,7 @@ func TestProcessCookieFailIfCookieExpired(t *testing.T) {
 	pcTest := NewProcessCookieTestWithDefaults()
 	pcTest.proxy.CookieExpire = time.Duration(24) * time.Hour
 	reference := time.Now().Add(time.Duration(25) * time.Hour * -1)
-	startSession := &providers.SessionState{Email: "michael.bland@gsa.gov", AccessToken: "my_access_token"}
+	startSession := &sessions.SessionState{Email: "michael.bland@gsa.gov", AccessToken: "my_access_token"}
 	pcTest.SaveSession(startSession, reference)

 	session, _, err := pcTest.LoadCookiedSession()
@ -709,7 +710,7 @@ func TestProcessCookieFailIfRefreshSetAndCookieExpired(t *testing.T) {
 	pcTest := NewProcessCookieTestWithDefaults()
 	pcTest.proxy.CookieExpire = time.Duration(24) * time.Hour
 	reference := time.Now().Add(time.Duration(25) * time.Hour * -1)
-	startSession := &providers.SessionState{Email: "michael.bland@gsa.gov", AccessToken: "my_access_token"}
+	startSession := &sessions.SessionState{Email: "michael.bland@gsa.gov", AccessToken: "my_access_token"}
 	pcTest.SaveSession(startSession, reference)

 	pcTest.proxy.CookieRefresh = time.Hour
@ -729,7 +730,7 @@ func NewAuthOnlyEndpointTest() *ProcessCookieTest {

 func TestAuthOnlyEndpointAccepted(t *testing.T) {
 	test := NewAuthOnlyEndpointTest()
-	startSession := &providers.SessionState{
+	startSession := &sessions.SessionState{
 		Email: "michael.bland@gsa.gov", AccessToken: "my_access_token"}
 	test.SaveSession(startSession, time.Now())

@ -752,7 +753,7 @@ func TestAuthOnlyEndpointUnauthorizedOnExpiration(t *testing.T) {
 	test := NewAuthOnlyEndpointTest()
 	test.proxy.CookieExpire = time.Duration(24) * time.Hour
 	reference := time.Now().Add(time.Duration(25) * time.Hour * -1)
-	startSession := &providers.SessionState{
+	startSession := &sessions.SessionState{
 		Email: "michael.bland@gsa.gov", AccessToken: "my_access_token"}
 	test.SaveSession(startSession, reference)

@ -764,7 +765,7 @@ func TestAuthOnlyEndpointUnauthorizedOnExpiration(t *testing.T) {

 func TestAuthOnlyEndpointUnauthorizedOnEmailValidationFailure(t *testing.T) {
 	test := NewAuthOnlyEndpointTest()
-	startSession := &providers.SessionState{
+	startSession := &sessions.SessionState{
 		Email: "michael.bland@gsa.gov", AccessToken: "my_access_token"}
 	test.SaveSession(startSession, time.Now())
 	test.validateUser = false
@ -795,7 +796,7 @@ func TestAuthOnlyEndpointSetXAuthRequestHeaders(t *testing.T) {
 	pcTest.req, _ = http.NewRequest("GET",
 		pcTest.opts.ProxyPrefix+"/auth", nil)

-	startSession := &providers.SessionState{
+	startSession := &sessions.SessionState{
 		User: "oauth_user", Email: "oauth_user@example.com", AccessToken: "oauth_token"}
 	pcTest.SaveSession(startSession, time.Now())

@ -927,7 +928,7 @@ func (st *SignatureTest) MakeRequestWithExpectedKey(method, body, key string) {
 	req := httptest.NewRequest(method, "/foo/bar", bodyBuf)
 	req.Header = st.header

-	state := &providers.SessionState{
+	state := &sessions.SessionState{
 		Email: "mbland@acm.org", AccessToken: "my_access_token"}
 	value, err := proxy.provider.CookieForSession(state, proxy.CookieCipher)
 	if err != nil {
--- a/options.go
+++ b/options.go
@ -18,6 +18,7 @@ import (
 	"github.com/dgrijalva/jwt-go"
 	"github.com/mbland/hmacauth"
 	"github.com/pusher/oauth2_proxy/logger"
+	"github.com/pusher/oauth2_proxy/pkg/apis/options"
 	"github.com/pusher/oauth2_proxy/providers"
 	"gopkg.in/natefinch/lumberjack.v2"
 )
@ -49,14 +50,11 @@ type Options struct {
 	CustomTemplatesDir       string   `flag:"custom-templates-dir" cfg:"custom_templates_dir" env:"OAUTH2_PROXY_CUSTOM_TEMPLATES_DIR"`
 	Footer                   string   `flag:"footer" cfg:"footer" env:"OAUTH2_PROXY_FOOTER"`

-	CookieName     string        `flag:"cookie-name" cfg:"cookie_name" env:"OAUTH2_PROXY_COOKIE_NAME"`
-	CookieSecret   string        `flag:"cookie-secret" cfg:"cookie_secret" env:"OAUTH2_PROXY_COOKIE_SECRET"`
-	CookieDomain   string        `flag:"cookie-domain" cfg:"cookie_domain" env:"OAUTH2_PROXY_COOKIE_DOMAIN"`
-	CookiePath     string        `flag:"cookie-path" cfg:"cookie_path" env:"OAUTH2_PROXY_COOKIE_PATH"`
-	CookieExpire   time.Duration `flag:"cookie-expire" cfg:"cookie_expire" env:"OAUTH2_PROXY_COOKIE_EXPIRE"`
-	CookieRefresh  time.Duration `flag:"cookie-refresh" cfg:"cookie_refresh" env:"OAUTH2_PROXY_COOKIE_REFRESH"`
-	CookieSecure   bool          `flag:"cookie-secure" cfg:"cookie_secure" env:"OAUTH2_PROXY_COOKIE_SECURE"`
-	CookieHTTPOnly bool          `flag:"cookie-httponly" cfg:"cookie_httponly" env:"OAUTH2_PROXY_COOKIE_HTTPONLY"`
+	// Embed CookieOptions
+	options.CookieOptions
+
+	// Embed SessionOptions
+	options.SessionOptions

 	Upstreams             []string      `flag:"upstream" cfg:"upstreams" env:"OAUTH2_PROXY_UPSTREAMS"`
 	SkipAuthRegex         []string      `flag:"skip-auth-regex" cfg:"skip_auth_regex" env:"OAUTH2_PROXY_SKIP_AUTH_REGEX"`
@ -126,16 +124,18 @@ type SignatureData struct {
 // NewOptions constructs a new Options with defaulted values
 func NewOptions() *Options {
 	return &Options{
-		ProxyPrefix:           "/oauth2",
-		ProxyWebSockets:       true,
-		HTTPAddress:           "127.0.0.1:4180",
-		HTTPSAddress:          ":443",
-		DisplayHtpasswdForm:   true,
-		CookieName:            "_oauth2_proxy",
-		CookieSecure:          true,
-		CookieHTTPOnly:        true,
-		CookieExpire:          time.Duration(168) * time.Hour,
-		CookieRefresh:         time.Duration(0),
+		ProxyPrefix:         "/oauth2",
+		ProxyWebSockets:     true,
+		HTTPAddress:         "127.0.0.1:4180",
+		HTTPSAddress:        ":443",
+		DisplayHtpasswdForm: true,
+		CookieOptions: options.CookieOptions{
+			CookieName:     "_oauth2_proxy",
+			CookieSecure:   true,
+			CookieHTTPOnly: true,
+			CookieExpire:   time.Duration(168) * time.Hour,
+			CookieRefresh:  time.Duration(0),
+		},
 		SetXAuthRequest:       false,
 		SkipAuthPreflight:     false,
 		PassBasicAuth:         true,
--- a/pkg/apis/options/cookie.go
+++ b/pkg/apis/options/cookie.go
@ -0,0 +1,15 @@
+package options
+
+import "time"
+
+// CookieOptions contains configuration options relating to Cookie configuration
+type CookieOptions struct {
+	CookieName     string        `flag:"cookie-name" cfg:"cookie_name" env:"OAUTH2_PROXY_COOKIE_NAME"`
+	CookieSecret   string        `flag:"cookie-secret" cfg:"cookie_secret" env:"OAUTH2_PROXY_COOKIE_SECRET"`
+	CookieDomain   string        `flag:"cookie-domain" cfg:"cookie_domain" env:"OAUTH2_PROXY_COOKIE_DOMAIN"`
+	CookiePath     string        `flag:"cookie-path" cfg:"cookie_path" env:"OAUTH2_PROXY_COOKIE_PATH"`
+	CookieExpire   time.Duration `flag:"cookie-expire" cfg:"cookie_expire" env:"OAUTH2_PROXY_COOKIE_EXPIRE"`
+	CookieRefresh  time.Duration `flag:"cookie-refresh" cfg:"cookie_refresh" env:"OAUTH2_PROXY_COOKIE_REFRESH"`
+	CookieSecure   bool          `flag:"cookie-secure" cfg:"cookie_secure" env:"OAUTH2_PROXY_COOKIE_SECURE"`
+	CookieHTTPOnly bool          `flag:"cookie-httponly" cfg:"cookie_httponly" env:"OAUTH2_PROXY_COOKIE_HTTPONLY"`
+}
--- a/pkg/apis/options/sessions.go
+++ b/pkg/apis/options/sessions.go
@ -0,0 +1,14 @@
+package options
+
+// SessionOptions contains configuration options for the SessionStore providers.
+type SessionOptions struct {
+	Type string `flag:"session-store-type" cfg:"session_store_type" env:"OAUTH2_PROXY_SESSION_STORE_TYPE"`
+	CookieStoreOptions
+}
+
+// CookieSessionStoreType is used to indicate the CookieSessionStore should be
+// used for storing sessions.
+var CookieSessionStoreType = "cookie"
+
+// CookieStoreOptions contains configuration options for the CookieSessionStore.
+type CookieStoreOptions struct{}
--- a/pkg/apis/sessions/interfaces.go
+++ b/pkg/apis/sessions/interfaces.go
@ -0,0 +1,12 @@
+package sessions
+
+import (
+	"net/http"
+)
+
+// SessionStore is an interface to storing user sessions in the proxy
+type SessionStore interface {
+	Save(rw http.ResponseWriter, req *http.Request, s *SessionState) error
+	Load(req *http.Request) (*SessionState, error)
+	Clear(rw http.ResponseWriter, req *http.Request) error
+}
--- a/pkg/apis/sessions/session_state.go
+++ b/pkg/apis/sessions/session_state.go
@ -1,4 +1,4 @@
-package providers
+package sessions

 import (
 	"encoding/json"
--- a/pkg/apis/sessions/session_state_test.go
+++ b/pkg/apis/sessions/session_state_test.go
@ -1,4 +1,4 @@
-package providers
+package sessions_test

 import (
 	"fmt"
@ -6,6 +6,7 @@ import (
 	"time"

 	"github.com/pusher/oauth2_proxy/cookie"
+	"github.com/pusher/oauth2_proxy/pkg/apis/sessions"
 	"github.com/stretchr/testify/assert"
 )

@ -17,7 +18,7 @@ func TestSessionStateSerialization(t *testing.T) {
 	assert.Equal(t, nil, err)
 	c2, err := cookie.NewCipher([]byte(altSecret))
 	assert.Equal(t, nil, err)
-	s := &SessionState{
+	s := &sessions.SessionState{
 		Email:        "user@domain.com",
 		AccessToken:  "token1234",
 		IDToken:      "rawtoken1234",
@ -27,7 +28,7 @@ func TestSessionStateSerialization(t *testing.T) {
 	encoded, err := s.EncodeSessionState(c)
 	assert.Equal(t, nil, err)

-	ss, err := DecodeSessionState(encoded, c)
+	ss, err := sessions.DecodeSessionState(encoded, c)
 	t.Logf("%#v", ss)
 	assert.Equal(t, nil, err)
 	assert.Equal(t, "user@domain.com", ss.User)
@ -38,7 +39,7 @@ func TestSessionStateSerialization(t *testing.T) {
 	assert.Equal(t, s.RefreshToken, ss.RefreshToken)

 	// ensure a different cipher can't decode properly (ie: it gets gibberish)
-	ss, err = DecodeSessionState(encoded, c2)
+	ss, err = sessions.DecodeSessionState(encoded, c2)
 	t.Logf("%#v", ss)
 	assert.Equal(t, nil, err)
 	assert.NotEqual(t, "user@domain.com", ss.User)
@ -54,7 +55,7 @@ func TestSessionStateSerializationWithUser(t *testing.T) {
 	assert.Equal(t, nil, err)
 	c2, err := cookie.NewCipher([]byte(altSecret))
 	assert.Equal(t, nil, err)
-	s := &SessionState{
+	s := &sessions.SessionState{
 		User:         "just-user",
 		Email:        "user@domain.com",
 		AccessToken:  "token1234",
@ -64,7 +65,7 @@ func TestSessionStateSerializationWithUser(t *testing.T) {
 	encoded, err := s.EncodeSessionState(c)
 	assert.Equal(t, nil, err)

-	ss, err := DecodeSessionState(encoded, c)
+	ss, err := sessions.DecodeSessionState(encoded, c)
 	t.Logf("%#v", ss)
 	assert.Equal(t, nil, err)
 	assert.Equal(t, s.User, ss.User)
@ -74,7 +75,7 @@ func TestSessionStateSerializationWithUser(t *testing.T) {
 	assert.Equal(t, s.RefreshToken, ss.RefreshToken)

 	// ensure a different cipher can't decode properly (ie: it gets gibberish)
-	ss, err = DecodeSessionState(encoded, c2)
+	ss, err = sessions.DecodeSessionState(encoded, c2)
 	t.Logf("%#v", ss)
 	assert.Equal(t, nil, err)
 	assert.NotEqual(t, s.User, ss.User)
@ -85,7 +86,7 @@ func TestSessionStateSerializationWithUser(t *testing.T) {
 }

 func TestSessionStateSerializationNoCipher(t *testing.T) {
-	s := &SessionState{
+	s := &sessions.SessionState{
 		Email:        "user@domain.com",
 		AccessToken:  "token1234",
 		ExpiresOn:    time.Now().Add(time.Duration(1) * time.Hour),
@ -95,7 +96,7 @@ func TestSessionStateSerializationNoCipher(t *testing.T) {
 	assert.Equal(t, nil, err)

 	// only email should have been serialized
-	ss, err := DecodeSessionState(encoded, nil)
+	ss, err := sessions.DecodeSessionState(encoded, nil)
 	assert.Equal(t, nil, err)
 	assert.Equal(t, "user@domain.com", ss.User)
 	assert.Equal(t, s.Email, ss.Email)
@ -104,7 +105,7 @@ func TestSessionStateSerializationNoCipher(t *testing.T) {
 }

 func TestSessionStateSerializationNoCipherWithUser(t *testing.T) {
-	s := &SessionState{
+	s := &sessions.SessionState{
 		User:         "just-user",
 		Email:        "user@domain.com",
 		AccessToken:  "token1234",
@ -115,7 +116,7 @@ func TestSessionStateSerializationNoCipherWithUser(t *testing.T) {
 	assert.Equal(t, nil, err)

 	// only email should have been serialized
-	ss, err := DecodeSessionState(encoded, nil)
+	ss, err := sessions.DecodeSessionState(encoded, nil)
 	assert.Equal(t, nil, err)
 	assert.Equal(t, s.User, ss.User)
 	assert.Equal(t, s.Email, ss.Email)
@ -124,18 +125,18 @@ func TestSessionStateSerializationNoCipherWithUser(t *testing.T) {
 }

 func TestExpired(t *testing.T) {
-	s := &SessionState{ExpiresOn: time.Now().Add(time.Duration(-1) * time.Minute)}
+	s := &sessions.SessionState{ExpiresOn: time.Now().Add(time.Duration(-1) * time.Minute)}
 	assert.Equal(t, true, s.IsExpired())

-	s = &SessionState{ExpiresOn: time.Now().Add(time.Duration(1) * time.Minute)}
+	s = &sessions.SessionState{ExpiresOn: time.Now().Add(time.Duration(1) * time.Minute)}
 	assert.Equal(t, false, s.IsExpired())

-	s = &SessionState{}
+	s = &sessions.SessionState{}
 	assert.Equal(t, false, s.IsExpired())
 }

 type testCase struct {
-	SessionState
+	sessions.SessionState
 	Encoded string
 	Cipher  *cookie.Cipher
 	Error   bool
@ -150,14 +151,14 @@ func TestEncodeSessionState(t *testing.T) {

 	testCases := []testCase{
 		{
-			SessionState: SessionState{
+			SessionState: sessions.SessionState{
 				Email: "user@domain.com",
 				User:  "just-user",
 			},
 			Encoded: `{"Email":"user@domain.com","User":"just-user"}`,
 		},
 		{
-			SessionState: SessionState{
+			SessionState: sessions.SessionState{
 				Email:        "user@domain.com",
 				User:         "just-user",
 				AccessToken:  "token1234",
@ -171,7 +172,7 @@ func TestEncodeSessionState(t *testing.T) {

 	for i, tc := range testCases {
 		encoded, err := tc.EncodeSessionState(tc.Cipher)
-		t.Logf("i:%d Encoded:%#v SessionState:%#v Error:%#v", i, encoded, tc.SessionState, err)
+		t.Logf("i:%d Encoded:%#vsessions.SessionState:%#v Error:%#v", i, encoded, tc.SessionState, err)
 		if tc.Error {
 			assert.Error(t, err)
 			assert.Empty(t, encoded)
@ -182,7 +183,7 @@ func TestEncodeSessionState(t *testing.T) {
 	}
 }

-// TestDecodeSessionState tests DecodeSessionState with the test vector
+// TestDecodeSessionState testssessions.DecodeSessionState with the test vector
 func TestDecodeSessionState(t *testing.T) {
 	e := time.Now().Add(time.Duration(1) * time.Hour)
 	eJSON, _ := e.MarshalJSON()
@ -194,34 +195,34 @@ func TestDecodeSessionState(t *testing.T) {

 	testCases := []testCase{
 		{
-			SessionState: SessionState{
+			SessionState: sessions.SessionState{
 				Email: "user@domain.com",
 				User:  "just-user",
 			},
 			Encoded: `{"Email":"user@domain.com","User":"just-user"}`,
 		},
 		{
-			SessionState: SessionState{
+			SessionState: sessions.SessionState{
 				Email: "user@domain.com",
 				User:  "user@domain.com",
 			},
 			Encoded: `{"Email":"user@domain.com"}`,
 		},
 		{
-			SessionState: SessionState{
+			SessionState: sessions.SessionState{
 				User: "just-user",
 			},
 			Encoded: `{"User":"just-user"}`,
 		},
 		{
-			SessionState: SessionState{
+			SessionState: sessions.SessionState{
 				Email: "user@domain.com",
 				User:  "just-user",
 			},
 			Encoded: fmt.Sprintf(`{"Email":"user@domain.com","User":"just-user","AccessToken":"I6s+ml+/MldBMgHIiC35BTKTh57skGX24w==","IDToken":"xojNdyyjB1HgYWh6XMtXY/Ph5eCVxa1cNsklJw==","RefreshToken":"qEX0x6RmASxo4dhlBG6YuRs9Syn/e9sHu/+K","ExpiresOn":%s}`, eString),
 		},
 		{
-			SessionState: SessionState{
+			SessionState: sessions.SessionState{
 				Email:        "user@domain.com",
 				User:         "just-user",
 				AccessToken:  "token1234",
@ -233,7 +234,7 @@ func TestDecodeSessionState(t *testing.T) {
 			Cipher:  c,
 		},
 		{
-			SessionState: SessionState{
+			SessionState: sessions.SessionState{
 				Email: "user@domain.com",
 				User:  "just-user",
 			},
@ -251,7 +252,7 @@ func TestDecodeSessionState(t *testing.T) {
 			Error:   true,
 		},
 		{
-			SessionState: SessionState{
+			SessionState: sessions.SessionState{
 				User:  "just-user",
 				Email: "user@domain.com",
 			},
@ -272,7 +273,7 @@ func TestDecodeSessionState(t *testing.T) {
 			Error:   true,
 		},
 		{
-			SessionState: SessionState{
+			SessionState: sessions.SessionState{
 				Email:        "user@domain.com",
 				User:         "just-user",
 				AccessToken:  "token1234",
@ -283,7 +284,7 @@ func TestDecodeSessionState(t *testing.T) {
 			Cipher:  c,
 		},
 		{
-			SessionState: SessionState{
+			SessionState: sessions.SessionState{
 				Email:        "user@domain.com",
 				User:         "just-user",
 				AccessToken:  "token1234",
@ -297,8 +298,8 @@ func TestDecodeSessionState(t *testing.T) {
 	}

 	for i, tc := range testCases {
-		ss, err := DecodeSessionState(tc.Encoded, tc.Cipher)
-		t.Logf("i:%d Encoded:%#v SessionState:%#v Error:%#v", i, tc.Encoded, ss, err)
+		ss, err := sessions.DecodeSessionState(tc.Encoded, tc.Cipher)
+		t.Logf("i:%d Encoded:%#vsessions.SessionState:%#v Error:%#v", i, tc.Encoded, ss, err)
 		if tc.Error {
 			assert.Error(t, err)
 			assert.Nil(t, ss)
--- a/pkg/cookies/cookies.go
+++ b/pkg/cookies/cookies.go
@ -0,0 +1,34 @@
+package cookies
+
+import (
+	"net"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/pusher/oauth2_proxy/logger"
+)
+
+// MakeCookie constructs a cookie from the given parameters,
+// discovering the domain from the request if not specified.
+func MakeCookie(req *http.Request, name string, value string, path string, domain string, httpOnly bool, secure bool, expiration time.Duration, now time.Time) *http.Cookie {
+	if domain != "" {
+		host := req.Host
+		if h, _, err := net.SplitHostPort(host); err == nil {
+			host = h
+		}
+		if !strings.HasSuffix(host, domain) {
+			logger.Printf("Warning: request host is %q but using configured cookie domain of %q", host, domain)
+		}
+	}
+
+	return &http.Cookie{
+		Name:     name,
+		Value:    value,
+		Path:     path,
+		Domain:   domain,
+		HttpOnly: httpOnly,
+		Secure:   secure,
+		Expires:  now.Add(expiration),
+	}
+}
--- a/pkg/sessions/cookie/session_store.go
+++ b/pkg/sessions/cookie/session_store.go
@ -0,0 +1,232 @@
+package cookie
+
+import (
+	"errors"
+	"fmt"
+	"net/http"
+	"regexp"
+	"strings"
+	"time"
+
+	"github.com/pusher/oauth2_proxy/cookie"
+	"github.com/pusher/oauth2_proxy/pkg/apis/options"
+	"github.com/pusher/oauth2_proxy/pkg/apis/sessions"
+	"github.com/pusher/oauth2_proxy/pkg/cookies"
+	"github.com/pusher/oauth2_proxy/pkg/sessions/utils"
+)
+
+const (
+	// Cookies are limited to 4kb including the length of the cookie name,
+	// the cookie name can be up to 256 bytes
+	maxCookieLength = 3840
+)
+
+// Ensure CookieSessionStore implements the interface
+var _ sessions.SessionStore = &SessionStore{}
+
+// SessionStore is an implementation of the sessions.SessionStore
+// interface that stores sessions in client side cookies
+type SessionStore struct {
+	CookieCipher   *cookie.Cipher
+	CookieDomain   string
+	CookieExpire   time.Duration
+	CookieHTTPOnly bool
+	CookieName     string
+	CookiePath     string
+	CookieSecret   string
+	CookieSecure   bool
+}
+
+// Save takes a sessions.SessionState and stores the information from it
+// within Cookies set on the HTTP response writer
+func (s *SessionStore) Save(rw http.ResponseWriter, req *http.Request, ss *sessions.SessionState) error {
+	value, err := utils.CookieForSession(ss, s.CookieCipher)
+	if err != nil {
+		return err
+	}
+	s.setSessionCookie(rw, req, value)
+	return nil
+}
+
+// Load reads sessions.SessionState information from Cookies within the
+// HTTP request object
+func (s *SessionStore) Load(req *http.Request) (*sessions.SessionState, error) {
+	c, err := loadCookie(req, s.CookieName)
+	if err != nil {
+		// always http.ErrNoCookie
+		return nil, fmt.Errorf("Cookie %q not present", s.CookieName)
+	}
+	val, _, ok := cookie.Validate(c, s.CookieSecret, s.CookieExpire)
+	if !ok {
+		return nil, errors.New("Cookie Signature not valid")
+	}
+
+	session, err := utils.SessionFromCookie(val, s.CookieCipher)
+	if err != nil {
+		return nil, err
+	}
+	return session, nil
+}
+
+// Clear clears any saved session information by writing a cookie to
+// clear the session
+func (s *SessionStore) Clear(rw http.ResponseWriter, req *http.Request) error {
+	var cookies []*http.Cookie
+
+	// matches CookieName, CookieName_<number>
+	var cookieNameRegex = regexp.MustCompile(fmt.Sprintf("^%s(_\\d+)?$", s.CookieName))
+
+	for _, c := range req.Cookies() {
+		if cookieNameRegex.MatchString(c.Name) {
+			clearCookie := s.makeCookie(req, c.Name, "", time.Hour*-1)
+
+			http.SetCookie(rw, clearCookie)
+			cookies = append(cookies, clearCookie)
+		}
+	}
+
+	return nil
+}
+
+// setSessionCookie adds the user's session cookie to the response
+func (s *SessionStore) setSessionCookie(rw http.ResponseWriter, req *http.Request, val string) {
+	for _, c := range s.makeSessionCookie(req, val, s.CookieExpire, time.Now()) {
+		http.SetCookie(rw, c)
+	}
+}
+
+// makeSessionCookie creates an http.Cookie containing the authenticated user's
+// authentication details
+func (s *SessionStore) makeSessionCookie(req *http.Request, value string, expiration time.Duration, now time.Time) []*http.Cookie {
+	if value != "" {
+		value = cookie.SignedValue(s.CookieSecret, s.CookieName, value, now)
+	}
+	c := s.makeCookie(req, s.CookieName, value, expiration)
+	if len(c.Value) > 4096-len(s.CookieName) {
+		return splitCookie(c)
+	}
+	return []*http.Cookie{c}
+}
+
+func (s *SessionStore) makeCookie(req *http.Request, name string, value string, expiration time.Duration) *http.Cookie {
+	return cookies.MakeCookie(
+		req,
+		name,
+		value,
+		s.CookiePath,
+		s.CookieDomain,
+		s.CookieHTTPOnly,
+		s.CookieSecure,
+		expiration,
+		time.Now(),
+	)
+}
+
+// NewCookieSessionStore initialises a new instance of the SessionStore from
+// the configuration given
+func NewCookieSessionStore(opts options.CookieStoreOptions, cookieOpts *options.CookieOptions) (sessions.SessionStore, error) {
+	var cipher *cookie.Cipher
+	if len(cookieOpts.CookieSecret) > 0 {
+		var err error
+		cipher, err = cookie.NewCipher(utils.SecretBytes(cookieOpts.CookieSecret))
+		if err != nil {
+			return nil, fmt.Errorf("unable to create cipher: %v", err)
+		}
+	}
+
+	return &SessionStore{
+		CookieCipher:   cipher,
+		CookieDomain:   cookieOpts.CookieDomain,
+		CookieExpire:   cookieOpts.CookieExpire,
+		CookieHTTPOnly: cookieOpts.CookieHTTPOnly,
+		CookieName:     cookieOpts.CookieName,
+		CookiePath:     cookieOpts.CookiePath,
+		CookieSecret:   cookieOpts.CookieSecret,
+		CookieSecure:   cookieOpts.CookieSecure,
+	}, nil
+}
+
+// splitCookie reads the full cookie generated to store the session and splits
+// it into a slice of cookies which fit within the 4kb cookie limit indexing
+// the cookies from 0
+func splitCookie(c *http.Cookie) []*http.Cookie {
+	if len(c.Value) < maxCookieLength {
+		return []*http.Cookie{c}
+	}
+	cookies := []*http.Cookie{}
+	valueBytes := []byte(c.Value)
+	count := 0
+	for len(valueBytes) > 0 {
+		new := copyCookie(c)
+		new.Name = fmt.Sprintf("%s_%d", c.Name, count)
+		count++
+		if len(valueBytes) < maxCookieLength {
+			new.Value = string(valueBytes)
+			valueBytes = []byte{}
+		} else {
+			newValue := valueBytes[:maxCookieLength]
+			valueBytes = valueBytes[maxCookieLength:]
+			new.Value = string(newValue)
+		}
+		cookies = append(cookies, new)
+	}
+	return cookies
+}
+
+// loadCookie retreieves the sessions state cookie from the http request.
+// If a single cookie is present this will be returned, otherwise it attempts
+// to reconstruct a cookie split up by splitCookie
+func loadCookie(req *http.Request, cookieName string) (*http.Cookie, error) {
+	c, err := req.Cookie(cookieName)
+	if err == nil {
+		return c, nil
+	}
+	cookies := []*http.Cookie{}
+	err = nil
+	count := 0
+	for err == nil {
+		var c *http.Cookie
+		c, err = req.Cookie(fmt.Sprintf("%s_%d", cookieName, count))
+		if err == nil {
+			cookies = append(cookies, c)
+			count++
+		}
+	}
+	if len(cookies) == 0 {
+		return nil, fmt.Errorf("Could not find cookie %s", cookieName)
+	}
+	return joinCookies(cookies)
+}
+
+// joinCookies takes a slice of cookies from the request and reconstructs the
+// full session cookie
+func joinCookies(cookies []*http.Cookie) (*http.Cookie, error) {
+	if len(cookies) == 0 {
+		return nil, fmt.Errorf("list of cookies must be > 0")
+	}
+	if len(cookies) == 1 {
+		return cookies[0], nil
+	}
+	c := copyCookie(cookies[0])
+	for i := 1; i < len(cookies); i++ {
+		c.Value += cookies[i].Value
+	}
+	c.Name = strings.TrimRight(c.Name, "_0")
+	return c, nil
+}
+
+func copyCookie(c *http.Cookie) *http.Cookie {
+	return &http.Cookie{
+		Name:       c.Name,
+		Value:      c.Value,
+		Path:       c.Path,
+		Domain:     c.Domain,
+		Expires:    c.Expires,
+		RawExpires: c.RawExpires,
+		MaxAge:     c.MaxAge,
+		Secure:     c.Secure,
+		HttpOnly:   c.HttpOnly,
+		Raw:        c.Raw,
+		Unparsed:   c.Unparsed,
+	}
+}
--- a/pkg/sessions/session_store.go
+++ b/pkg/sessions/session_store.go
@ -0,0 +1,19 @@
+package sessions
+
+import (
+	"fmt"
+
+	"github.com/pusher/oauth2_proxy/pkg/apis/options"
+	"github.com/pusher/oauth2_proxy/pkg/apis/sessions"
+	"github.com/pusher/oauth2_proxy/pkg/sessions/cookie"
+)
+
+// NewSessionStore creates a SessionStore from the provided configuration
+func NewSessionStore(opts *options.SessionOptions, cookieOpts *options.CookieOptions) (sessions.SessionStore, error) {
+	switch opts.Type {
+	case options.CookieSessionStoreType:
+		return cookie.NewCookieSessionStore(opts.CookieStoreOptions, cookieOpts)
+	default:
+		return nil, fmt.Errorf("unknown session store type '%s'", opts.Type)
+	}
+}
--- a/pkg/sessions/session_store_test.go
+++ b/pkg/sessions/session_store_test.go
@ -0,0 +1,254 @@
+package sessions_test
+
+import (
+	"crypto/rand"
+	"encoding/base64"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+	"github.com/pusher/oauth2_proxy/pkg/apis/options"
+	sessionsapi "github.com/pusher/oauth2_proxy/pkg/apis/sessions"
+	"github.com/pusher/oauth2_proxy/pkg/cookies"
+	"github.com/pusher/oauth2_proxy/pkg/sessions"
+	"github.com/pusher/oauth2_proxy/pkg/sessions/cookie"
+)
+
+func TestSessionStore(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "SessionStore")
+}
+
+var _ = Describe("NewSessionStore", func() {
+	var opts *options.SessionOptions
+	var cookieOpts *options.CookieOptions
+
+	var request *http.Request
+	var response *httptest.ResponseRecorder
+	var session *sessionsapi.SessionState
+	var ss sessionsapi.SessionStore
+
+	CheckCookieOptions := func() {
+		Context("the cookies returned", func() {
+			var cookies []*http.Cookie
+			BeforeEach(func() {
+				cookies = response.Result().Cookies()
+			})
+
+			It("have the correct name set", func() {
+				if len(cookies) == 1 {
+					Expect(cookies[0].Name).To(Equal(cookieOpts.CookieName))
+				} else {
+					for _, cookie := range cookies {
+						Expect(cookie.Name).To(ContainSubstring(cookieOpts.CookieName))
+					}
+				}
+			})
+
+			It("have the correct path set", func() {
+				for _, cookie := range cookies {
+					Expect(cookie.Path).To(Equal(cookieOpts.CookiePath))
+				}
+			})
+
+			It("have the correct domain set", func() {
+				for _, cookie := range cookies {
+					Expect(cookie.Domain).To(Equal(cookieOpts.CookieDomain))
+				}
+			})
+
+			It("have the correct HTTPOnly set", func() {
+				for _, cookie := range cookies {
+					Expect(cookie.HttpOnly).To(Equal(cookieOpts.CookieHTTPOnly))
+				}
+			})
+
+			It("have the correct secure set", func() {
+				for _, cookie := range cookies {
+					Expect(cookie.Secure).To(Equal(cookieOpts.CookieSecure))
+				}
+			})
+
+		})
+	}
+
+	SessionStoreInterfaceTests := func() {
+		Context("when Save is called", func() {
+			BeforeEach(func() {
+				err := ss.Save(response, request, session)
+				Expect(err).ToNot(HaveOccurred())
+			})
+
+			It("sets a `set-cookie` header in the response", func() {
+				Expect(response.Header().Get("set-cookie")).ToNot(BeEmpty())
+			})
+
+			CheckCookieOptions()
+		})
+
+		Context("when Clear is called", func() {
+			BeforeEach(func() {
+				cookie := cookies.MakeCookie(request,
+					cookieOpts.CookieName,
+					"foo",
+					cookieOpts.CookiePath,
+					cookieOpts.CookieDomain,
+					cookieOpts.CookieHTTPOnly,
+					cookieOpts.CookieSecure,
+					cookieOpts.CookieExpire,
+					time.Now(),
+				)
+				request.AddCookie(cookie)
+				err := ss.Clear(response, request)
+				Expect(err).ToNot(HaveOccurred())
+			})
+
+			It("sets a `set-cookie` header in the response", func() {
+				Expect(response.Header().Get("Set-Cookie")).ToNot(BeEmpty())
+			})
+
+			CheckCookieOptions()
+		})
+
+		Context("when Load is called", func() {
+			var loadedSession *sessionsapi.SessionState
+			BeforeEach(func() {
+				req := httptest.NewRequest("GET", "http://example.com/", nil)
+				resp := httptest.NewRecorder()
+				err := ss.Save(resp, req, session)
+				Expect(err).ToNot(HaveOccurred())
+
+				for _, cookie := range resp.Result().Cookies() {
+					request.AddCookie(cookie)
+				}
+				loadedSession, err = ss.Load(request)
+				Expect(err).ToNot(HaveOccurred())
+			})
+
+			It("loads a session equal to the original session", func() {
+				if cookieOpts.CookieSecret == "" {
+					// Only Email and User stored in session when encrypted
+					Expect(loadedSession.Email).To(Equal(session.Email))
+					Expect(loadedSession.User).To(Equal(session.User))
+				} else {
+					// All fields stored in session if encrypted
+
+					// Can't compare time.Time using Equal() so remove ExpiresOn from sessions
+					l := *loadedSession
+					l.ExpiresOn = time.Time{}
+					s := *session
+					s.ExpiresOn = time.Time{}
+					Expect(l).To(Equal(s))
+
+					// Compare time.Time separately
+					Expect(loadedSession.ExpiresOn.Equal(session.ExpiresOn)).To(BeTrue())
+				}
+			})
+		})
+	}
+
+	RunSessionTests := func() {
+		Context("with default options", func() {
+			BeforeEach(func() {
+				var err error
+				ss, err = sessions.NewSessionStore(opts, cookieOpts)
+				Expect(err).ToNot(HaveOccurred())
+			})
+
+			SessionStoreInterfaceTests()
+		})
+
+		Context("with non-default options", func() {
+			BeforeEach(func() {
+				cookieOpts = &options.CookieOptions{
+					CookieName:     "_cookie_name",
+					CookiePath:     "/path",
+					CookieExpire:   time.Duration(72) * time.Hour,
+					CookieRefresh:  time.Duration(3600),
+					CookieSecure:   false,
+					CookieHTTPOnly: false,
+					CookieDomain:   "example.com",
+				}
+
+				var err error
+				ss, err = sessions.NewSessionStore(opts, cookieOpts)
+				Expect(err).ToNot(HaveOccurred())
+			})
+
+			SessionStoreInterfaceTests()
+		})
+
+		Context("with a cookie-secret set", func() {
+			BeforeEach(func() {
+				secret := make([]byte, 32)
+				_, err := rand.Read(secret)
+				Expect(err).ToNot(HaveOccurred())
+				cookieOpts.CookieSecret = base64.URLEncoding.EncodeToString(secret)
+
+				ss, err = sessions.NewSessionStore(opts, cookieOpts)
+				Expect(err).ToNot(HaveOccurred())
+			})
+
+			SessionStoreInterfaceTests()
+		})
+	}
+
+	BeforeEach(func() {
+		ss = nil
+		opts = &options.SessionOptions{}
+
+		// Set default options in CookieOptions
+		cookieOpts = &options.CookieOptions{
+			CookieName:     "_oauth2_proxy",
+			CookiePath:     "/",
+			CookieExpire:   time.Duration(168) * time.Hour,
+			CookieRefresh:  time.Duration(0),
+			CookieSecure:   true,
+			CookieHTTPOnly: true,
+		}
+
+		session = &sessionsapi.SessionState{
+			AccessToken:  "AccessToken",
+			IDToken:      "IDToken",
+			ExpiresOn:    time.Now().Add(1 * time.Hour),
+			RefreshToken: "RefreshToken",
+			Email:        "john.doe@example.com",
+			User:         "john.doe",
+		}
+
+		request = httptest.NewRequest("GET", "http://example.com/", nil)
+		response = httptest.NewRecorder()
+	})
+
+	Context("with type 'cookie'", func() {
+		BeforeEach(func() {
+			opts.Type = options.CookieSessionStoreType
+		})
+
+		It("creates a cookie.SessionStore", func() {
+			ss, err := sessions.NewSessionStore(opts, cookieOpts)
+			Expect(err).NotTo(HaveOccurred())
+			Expect(ss).To(BeAssignableToTypeOf(&cookie.SessionStore{}))
+		})
+
+		Context("the cookie.SessionStore", func() {
+			RunSessionTests()
+		})
+	})
+
+	Context("with an invalid type", func() {
+		BeforeEach(func() {
+			opts.Type = "invalid-type"
+		})
+
+		It("returns an error", func() {
+			ss, err := sessions.NewSessionStore(opts, cookieOpts)
+			Expect(err).To(HaveOccurred())
+			Expect(err.Error()).To(Equal("unknown session store type 'invalid-type'"))
+			Expect(ss).To(BeNil())
+		})
+	})
+})
--- a/pkg/sessions/utils/utils.go
+++ b/pkg/sessions/utils/utils.go
@ -0,0 +1,41 @@
+package utils
+
+import (
+	"encoding/base64"
+
+	"github.com/pusher/oauth2_proxy/cookie"
+	"github.com/pusher/oauth2_proxy/pkg/apis/sessions"
+)
+
+// CookieForSession serializes a session state for storage in a cookie
+func CookieForSession(s *sessions.SessionState, c *cookie.Cipher) (string, error) {
+	return s.EncodeSessionState(c)
+}
+
+// SessionFromCookie deserializes a session from a cookie value
+func SessionFromCookie(v string, c *cookie.Cipher) (s *sessions.SessionState, err error) {
+	return sessions.DecodeSessionState(v, c)
+}
+
+// SecretBytes attempts to base64 decode the secret, if that fails it treats the secret as binary
+func SecretBytes(secret string) []byte {
+	b, err := base64.URLEncoding.DecodeString(addPadding(secret))
+	if err == nil {
+		return []byte(addPadding(string(b)))
+	}
+	return []byte(secret)
+}
+
+func addPadding(secret string) string {
+	padding := len(secret) % 4
+	switch padding {
+	case 1:
+		return secret + "==="
+	case 2:
+		return secret + "=="
+	case 3:
+		return secret + "="
+	default:
+		return secret
+	}
+}
--- a/providers/azure.go
+++ b/providers/azure.go
@ -9,6 +9,7 @@ import (
 	"github.com/bitly/go-simplejson"
 	"github.com/pusher/oauth2_proxy/api"
 	"github.com/pusher/oauth2_proxy/logger"
+	"github.com/pusher/oauth2_proxy/pkg/apis/sessions"
 )

 // AzureProvider represents an Azure based Identity Provider
@ -88,7 +89,7 @@ func getEmailFromJSON(json *simplejson.Json) (string, error) {
 }

 // GetEmailAddress returns the Account email address
-func (p *AzureProvider) GetEmailAddress(s *SessionState) (string, error) {
+func (p *AzureProvider) GetEmailAddress(s *sessions.SessionState) (string, error) {
 	var email string
 	var err error

--- a/providers/azure_test.go
+++ b/providers/azure_test.go
@ -6,6 +6,7 @@ import (
 	"net/url"
 	"testing"

+	"github.com/pusher/oauth2_proxy/pkg/apis/sessions"
 	"github.com/stretchr/testify/assert"
 )

@ -128,7 +129,7 @@ func TestAzureProviderGetEmailAddress(t *testing.T) {
 	bURL, _ := url.Parse(b.URL)
 	p := testAzureProvider(bURL.Host)

-	session := &SessionState{AccessToken: "imaginary_access_token"}
+	session := &sessions.SessionState{AccessToken: "imaginary_access_token"}
 	email, err := p.GetEmailAddress(session)
 	assert.Equal(t, nil, err)
 	assert.Equal(t, "user@windows.net", email)
@ -141,7 +142,7 @@ func TestAzureProviderGetEmailAddressMailNull(t *testing.T) {
 	bURL, _ := url.Parse(b.URL)
 	p := testAzureProvider(bURL.Host)

-	session := &SessionState{AccessToken: "imaginary_access_token"}
+	session := &sessions.SessionState{AccessToken: "imaginary_access_token"}
 	email, err := p.GetEmailAddress(session)
 	assert.Equal(t, nil, err)
 	assert.Equal(t, "user@windows.net", email)
@ -154,7 +155,7 @@ func TestAzureProviderGetEmailAddressGetUserPrincipalName(t *testing.T) {
 	bURL, _ := url.Parse(b.URL)
 	p := testAzureProvider(bURL.Host)

-	session := &SessionState{AccessToken: "imaginary_access_token"}
+	session := &sessions.SessionState{AccessToken: "imaginary_access_token"}
 	email, err := p.GetEmailAddress(session)
 	assert.Equal(t, nil, err)
 	assert.Equal(t, "user@windows.net", email)
@ -167,7 +168,7 @@ func TestAzureProviderGetEmailAddressFailToGetEmailAddress(t *testing.T) {
 	bURL, _ := url.Parse(b.URL)
 	p := testAzureProvider(bURL.Host)

-	session := &SessionState{AccessToken: "imaginary_access_token"}
+	session := &sessions.SessionState{AccessToken: "imaginary_access_token"}
 	email, err := p.GetEmailAddress(session)
 	assert.Equal(t, "type assertion to string failed", err.Error())
 	assert.Equal(t, "", email)
@ -180,7 +181,7 @@ func TestAzureProviderGetEmailAddressEmptyUserPrincipalName(t *testing.T) {
 	bURL, _ := url.Parse(b.URL)
 	p := testAzureProvider(bURL.Host)

-	session := &SessionState{AccessToken: "imaginary_access_token"}
+	session := &sessions.SessionState{AccessToken: "imaginary_access_token"}
 	email, err := p.GetEmailAddress(session)
 	assert.Equal(t, nil, err)
 	assert.Equal(t, "", email)
@ -193,7 +194,7 @@ func TestAzureProviderGetEmailAddressIncorrectOtherMails(t *testing.T) {
 	bURL, _ := url.Parse(b.URL)
 	p := testAzureProvider(bURL.Host)

-	session := &SessionState{AccessToken: "imaginary_access_token"}
+	session := &sessions.SessionState{AccessToken: "imaginary_access_token"}
 	email, err := p.GetEmailAddress(session)
 	assert.Equal(t, "type assertion to string failed", err.Error())
 	assert.Equal(t, "", email)
--- a/providers/facebook.go
+++ b/providers/facebook.go
@ -7,6 +7,7 @@ import (
 	"net/url"

 	"github.com/pusher/oauth2_proxy/api"
+	"github.com/pusher/oauth2_proxy/pkg/apis/sessions"
 )

 // FacebookProvider represents an Facebook based Identity Provider
@ -54,7 +55,7 @@ func getFacebookHeader(accessToken string) http.Header {
 }

 // GetEmailAddress returns the Account email address
-func (p *FacebookProvider) GetEmailAddress(s *SessionState) (string, error) {
+func (p *FacebookProvider) GetEmailAddress(s *sessions.SessionState) (string, error) {
 	if s.AccessToken == "" {
 		return "", errors.New("missing access token")
 	}
@ -79,6 +80,6 @@ func (p *FacebookProvider) GetEmailAddress(s *SessionState) (string, error) {
 }

 // ValidateSessionState validates the AccessToken
-func (p *FacebookProvider) ValidateSessionState(s *SessionState) bool {
+func (p *FacebookProvider) ValidateSessionState(s *sessions.SessionState) bool {
 	return validateToken(p, s.AccessToken, getFacebookHeader(s.AccessToken))
 }
--- a/providers/github.go
+++ b/providers/github.go
@ -11,6 +11,7 @@ import (
 	"strings"

 	"github.com/pusher/oauth2_proxy/logger"
+	"github.com/pusher/oauth2_proxy/pkg/apis/sessions"
 )

 // GitHubProvider represents an GitHub based Identity Provider
@ -200,7 +201,7 @@ func (p *GitHubProvider) hasOrgAndTeam(accessToken string) (bool, error) {
 }

 // GetEmailAddress returns the Account email address
-func (p *GitHubProvider) GetEmailAddress(s *SessionState) (string, error) {
+func (p *GitHubProvider) GetEmailAddress(s *sessions.SessionState) (string, error) {

 	var emails []struct {
 		Email    string `json:"email"`
@ -259,7 +260,7 @@ func (p *GitHubProvider) GetEmailAddress(s *SessionState) (string, error) {
 }

 // GetUserName returns the Account user name
-func (p *GitHubProvider) GetUserName(s *SessionState) (string, error) {
+func (p *GitHubProvider) GetUserName(s *sessions.SessionState) (string, error) {
 	var user struct {
 		Login string `json:"login"`
 		Email string `json:"email"`
--- a/providers/github_test.go
+++ b/providers/github_test.go
@ -6,6 +6,7 @@ import (
 	"net/url"
 	"testing"

+	"github.com/pusher/oauth2_proxy/pkg/apis/sessions"
 	"github.com/stretchr/testify/assert"
 )

@ -103,7 +104,7 @@ func TestGitHubProviderGetEmailAddress(t *testing.T) {
 	bURL, _ := url.Parse(b.URL)
 	p := testGitHubProvider(bURL.Host)

-	session := &SessionState{AccessToken: "imaginary_access_token"}
+	session := &sessions.SessionState{AccessToken: "imaginary_access_token"}
 	email, err := p.GetEmailAddress(session)
 	assert.Equal(t, nil, err)
 	assert.Equal(t, "michael.bland@gsa.gov", email)
@ -116,7 +117,7 @@ func TestGitHubProviderGetEmailAddressNotVerified(t *testing.T) {
 	bURL, _ := url.Parse(b.URL)
 	p := testGitHubProvider(bURL.Host)

-	session := &SessionState{AccessToken: "imaginary_access_token"}
+	session := &sessions.SessionState{AccessToken: "imaginary_access_token"}
 	email, err := p.GetEmailAddress(session)
 	assert.Equal(t, nil, err)
 	assert.Empty(t, "", email)
@ -134,7 +135,7 @@ func TestGitHubProviderGetEmailAddressWithOrg(t *testing.T) {
 	p := testGitHubProvider(bURL.Host)
 	p.Org = "testorg1"

-	session := &SessionState{AccessToken: "imaginary_access_token"}
+	session := &sessions.SessionState{AccessToken: "imaginary_access_token"}
 	email, err := p.GetEmailAddress(session)
 	assert.Equal(t, nil, err)
 	assert.Equal(t, "michael.bland@gsa.gov", email)
@ -152,7 +153,7 @@ func TestGitHubProviderGetEmailAddressFailedRequest(t *testing.T) {
 	// We'll trigger a request failure by using an unexpected access
 	// token. Alternatively, we could allow the parsing of the payload as
 	// JSON to fail.
-	session := &SessionState{AccessToken: "unexpected_access_token"}
+	session := &sessions.SessionState{AccessToken: "unexpected_access_token"}
 	email, err := p.GetEmailAddress(session)
 	assert.NotEqual(t, nil, err)
 	assert.Equal(t, "", email)
@ -165,7 +166,7 @@ func TestGitHubProviderGetEmailAddressEmailNotPresentInPayload(t *testing.T) {
 	bURL, _ := url.Parse(b.URL)
 	p := testGitHubProvider(bURL.Host)

-	session := &SessionState{AccessToken: "imaginary_access_token"}
+	session := &sessions.SessionState{AccessToken: "imaginary_access_token"}
 	email, err := p.GetEmailAddress(session)
 	assert.NotEqual(t, nil, err)
 	assert.Equal(t, "", email)
@ -178,7 +179,7 @@ func TestGitHubProviderGetUserName(t *testing.T) {
 	bURL, _ := url.Parse(b.URL)
 	p := testGitHubProvider(bURL.Host)

-	session := &SessionState{AccessToken: "imaginary_access_token"}
+	session := &sessions.SessionState{AccessToken: "imaginary_access_token"}
 	email, err := p.GetUserName(session)
 	assert.Equal(t, nil, err)
 	assert.Equal(t, "mbland", email)
--- a/providers/gitlab.go
+++ b/providers/gitlab.go
@ -6,6 +6,7 @@ import (

 	"github.com/pusher/oauth2_proxy/api"
 	"github.com/pusher/oauth2_proxy/logger"
+	"github.com/pusher/oauth2_proxy/pkg/apis/sessions"
 )

 // GitLabProvider represents an GitLab based Identity Provider
@ -44,7 +45,7 @@ func NewGitLabProvider(p *ProviderData) *GitLabProvider {
 }

 // GetEmailAddress returns the Account email address
-func (p *GitLabProvider) GetEmailAddress(s *SessionState) (string, error) {
+func (p *GitLabProvider) GetEmailAddress(s *sessions.SessionState) (string, error) {

 	req, err := http.NewRequest("GET",
 		p.ValidateURL.String()+"?access_token="+s.AccessToken, nil)
--- a/providers/gitlab_test.go
+++ b/providers/gitlab_test.go
@ -6,6 +6,7 @@ import (
 	"net/url"
 	"testing"

+	"github.com/pusher/oauth2_proxy/pkg/apis/sessions"
 	"github.com/stretchr/testify/assert"
 )

@ -89,7 +90,7 @@ func TestGitLabProviderGetEmailAddress(t *testing.T) {
 	bURL, _ := url.Parse(b.URL)
 	p := testGitLabProvider(bURL.Host)

-	session := &SessionState{AccessToken: "imaginary_access_token"}
+	session := &sessions.SessionState{AccessToken: "imaginary_access_token"}
 	email, err := p.GetEmailAddress(session)
 	assert.Equal(t, nil, err)
 	assert.Equal(t, "michael.bland@gsa.gov", email)
@ -107,7 +108,7 @@ func TestGitLabProviderGetEmailAddressFailedRequest(t *testing.T) {
 	// We'll trigger a request failure by using an unexpected access
 	// token. Alternatively, we could allow the parsing of the payload as
 	// JSON to fail.
-	session := &SessionState{AccessToken: "unexpected_access_token"}
+	session := &sessions.SessionState{AccessToken: "unexpected_access_token"}
 	email, err := p.GetEmailAddress(session)
 	assert.NotEqual(t, nil, err)
 	assert.Equal(t, "", email)
@ -120,7 +121,7 @@ func TestGitLabProviderGetEmailAddressEmailNotPresentInPayload(t *testing.T) {
 	bURL, _ := url.Parse(b.URL)
 	p := testGitLabProvider(bURL.Host)

-	session := &SessionState{AccessToken: "imaginary_access_token"}
+	session := &sessions.SessionState{AccessToken: "imaginary_access_token"}
 	email, err := p.GetEmailAddress(session)
 	assert.NotEqual(t, nil, err)
 	assert.Equal(t, "", email)
--- a/providers/google.go
+++ b/providers/google.go
@ -14,6 +14,7 @@ import (
 	"time"

 	"github.com/pusher/oauth2_proxy/logger"
+	"github.com/pusher/oauth2_proxy/pkg/apis/sessions"
 	"golang.org/x/oauth2"
 	"golang.org/x/oauth2/google"
 	admin "google.golang.org/api/admin/directory/v1"
@ -96,7 +97,7 @@ func claimsFromIDToken(idToken string) (*claims, error) {
 }

 // Redeem exchanges the OAuth2 authentication token for an ID token
-func (p *GoogleProvider) Redeem(redirectURL, code string) (s *SessionState, err error) {
+func (p *GoogleProvider) Redeem(redirectURL, code string) (s *sessions.SessionState, err error) {
 	if code == "" {
 		err = errors.New("missing code")
 		return
@ -145,7 +146,7 @@ func (p *GoogleProvider) Redeem(redirectURL, code string) (s *SessionState, err
 	if err != nil {
 		return
 	}
-	s = &SessionState{
+	s = &sessions.SessionState{
 		AccessToken:  jsonResponse.AccessToken,
 		IDToken:      jsonResponse.IDToken,
 		ExpiresOn:    time.Now().Add(time.Duration(jsonResponse.ExpiresIn) * time.Second).Truncate(time.Second),
@ -258,7 +259,7 @@ func (p *GoogleProvider) ValidateGroup(email string) bool {

 // RefreshSessionIfNeeded checks if the session has expired and uses the
 // RefreshToken to fetch a new ID token if required
-func (p *GoogleProvider) RefreshSessionIfNeeded(s *SessionState) (bool, error) {
+func (p *GoogleProvider) RefreshSessionIfNeeded(s *sessions.SessionState) (bool, error) {
 	if s == nil || s.ExpiresOn.After(time.Now()) || s.RefreshToken == "" {
 		return false, nil
 	}
--- a/providers/internal_util_test.go
+++ b/providers/internal_util_test.go
@ -7,6 +7,7 @@ import (
 	"net/url"
 	"testing"

+	"github.com/pusher/oauth2_proxy/pkg/apis/sessions"
 	"github.com/stretchr/testify/assert"
 )

@ -19,13 +20,13 @@ type ValidateSessionStateTestProvider struct {
 	*ProviderData
 }

-func (tp *ValidateSessionStateTestProvider) GetEmailAddress(s *SessionState) (string, error) {
+func (tp *ValidateSessionStateTestProvider) GetEmailAddress(s *sessions.SessionState) (string, error) {
 	return "", errors.New("not implemented")
 }

 // Note that we're testing the internal validateToken() used to implement
 // several Provider's ValidateSessionState() implementations
-func (tp *ValidateSessionStateTestProvider) ValidateSessionState(s *SessionState) bool {
+func (tp *ValidateSessionStateTestProvider) ValidateSessionState(s *sessions.SessionState) bool {
 	return false
 }

--- a/providers/linkedin.go
+++ b/providers/linkedin.go
@ -7,6 +7,7 @@ import (
 	"net/url"

 	"github.com/pusher/oauth2_proxy/api"
+	"github.com/pusher/oauth2_proxy/pkg/apis/sessions"
 )

 // LinkedInProvider represents an LinkedIn based Identity Provider
@ -50,7 +51,7 @@ func getLinkedInHeader(accessToken string) http.Header {
 }

 // GetEmailAddress returns the Account email address
-func (p *LinkedInProvider) GetEmailAddress(s *SessionState) (string, error) {
+func (p *LinkedInProvider) GetEmailAddress(s *sessions.SessionState) (string, error) {
 	if s.AccessToken == "" {
 		return "", errors.New("missing access token")
 	}
@ -73,6 +74,6 @@ func (p *LinkedInProvider) GetEmailAddress(s *SessionState) (string, error) {
 }

 // ValidateSessionState validates the AccessToken
-func (p *LinkedInProvider) ValidateSessionState(s *SessionState) bool {
+func (p *LinkedInProvider) ValidateSessionState(s *sessions.SessionState) bool {
 	return validateToken(p, s.AccessToken, getLinkedInHeader(s.AccessToken))
 }
--- a/providers/linkedin_test.go
+++ b/providers/linkedin_test.go
@ -6,6 +6,7 @@ import (
 	"net/url"
 	"testing"

+	"github.com/pusher/oauth2_proxy/pkg/apis/sessions"
 	"github.com/stretchr/testify/assert"
 )

@ -97,7 +98,7 @@ func TestLinkedInProviderGetEmailAddress(t *testing.T) {
 	bURL, _ := url.Parse(b.URL)
 	p := testLinkedInProvider(bURL.Host)

-	session := &SessionState{AccessToken: "imaginary_access_token"}
+	session := &sessions.SessionState{AccessToken: "imaginary_access_token"}
 	email, err := p.GetEmailAddress(session)
 	assert.Equal(t, nil, err)
 	assert.Equal(t, "user@linkedin.com", email)
@ -113,7 +114,7 @@ func TestLinkedInProviderGetEmailAddressFailedRequest(t *testing.T) {
 	// We'll trigger a request failure by using an unexpected access
 	// token. Alternatively, we could allow the parsing of the payload as
 	// JSON to fail.
-	session := &SessionState{AccessToken: "unexpected_access_token"}
+	session := &sessions.SessionState{AccessToken: "unexpected_access_token"}
 	email, err := p.GetEmailAddress(session)
 	assert.NotEqual(t, nil, err)
 	assert.Equal(t, "", email)
@ -126,7 +127,7 @@ func TestLinkedInProviderGetEmailAddressEmailNotPresentInPayload(t *testing.T) {
 	bURL, _ := url.Parse(b.URL)
 	p := testLinkedInProvider(bURL.Host)

-	session := &SessionState{AccessToken: "imaginary_access_token"}
+	session := &sessions.SessionState{AccessToken: "imaginary_access_token"}
 	email, err := p.GetEmailAddress(session)
 	assert.NotEqual(t, nil, err)
 	assert.Equal(t, "", email)
--- a/providers/logingov.go
+++ b/providers/logingov.go
@ -13,6 +13,7 @@ import (
 	"time"

 	"github.com/dgrijalva/jwt-go"
+	"github.com/pusher/oauth2_proxy/pkg/apis/sessions"
 	"gopkg.in/square/go-jose.v2"
 )

@ -173,7 +174,7 @@ func emailFromUserInfo(accessToken string, userInfoEndpoint string) (email strin
 }

 // Redeem exchanges the OAuth2 authentication token for an ID token
-func (p *LoginGovProvider) Redeem(redirectURL, code string) (s *SessionState, err error) {
+func (p *LoginGovProvider) Redeem(redirectURL, code string) (s *sessions.SessionState, err error) {
 	if code == "" {
 		err = errors.New("missing code")
 		return
@ -248,7 +249,7 @@ func (p *LoginGovProvider) Redeem(redirectURL, code string) (s *SessionState, er
 	}

 	// Store the data that we found in the session state
-	s = &SessionState{
+	s = &sessions.SessionState{
 		AccessToken: jsonResponse.AccessToken,
 		IDToken:     jsonResponse.IDToken,
 		ExpiresOn:   time.Now().Add(time.Duration(jsonResponse.ExpiresIn) * time.Second).Truncate(time.Second),
--- a/providers/oidc.go
+++ b/providers/oidc.go
@ -5,9 +5,9 @@ import (
 	"fmt"
 	"time"

-	"golang.org/x/oauth2"
-
 	oidc "github.com/coreos/go-oidc"
+	"github.com/pusher/oauth2_proxy/pkg/apis/sessions"
+	"golang.org/x/oauth2"
 )

 // OIDCProvider represents an OIDC based Identity Provider
@ -24,7 +24,7 @@ func NewOIDCProvider(p *ProviderData) *OIDCProvider {
 }

 // Redeem exchanges the OAuth2 authentication token for an ID token
-func (p *OIDCProvider) Redeem(redirectURL, code string) (s *SessionState, err error) {
+func (p *OIDCProvider) Redeem(redirectURL, code string) (s *sessions.SessionState, err error) {
 	ctx := context.Background()
 	c := oauth2.Config{
 		ClientID:     p.ClientID,
@ -47,7 +47,7 @@ func (p *OIDCProvider) Redeem(redirectURL, code string) (s *SessionState, err er

 // RefreshSessionIfNeeded checks if the session has expired and uses the
 // RefreshToken to fetch a new ID token if required
-func (p *OIDCProvider) RefreshSessionIfNeeded(s *SessionState) (bool, error) {
+func (p *OIDCProvider) RefreshSessionIfNeeded(s *sessions.SessionState) (bool, error) {
 	if s == nil || s.ExpiresOn.After(time.Now()) || s.RefreshToken == "" {
 		return false, nil
 	}
@ -63,7 +63,7 @@ func (p *OIDCProvider) RefreshSessionIfNeeded(s *SessionState) (bool, error) {
 	return true, nil
 }

-func (p *OIDCProvider) redeemRefreshToken(s *SessionState) (err error) {
+func (p *OIDCProvider) redeemRefreshToken(s *sessions.SessionState) (err error) {
 	c := oauth2.Config{
 		ClientID:     p.ClientID,
 		ClientSecret: p.ClientSecret,
@ -92,7 +92,7 @@ func (p *OIDCProvider) redeemRefreshToken(s *SessionState) (err error) {
 	return
 }

-func (p *OIDCProvider) createSessionState(ctx context.Context, token *oauth2.Token) (*SessionState, error) {
+func (p *OIDCProvider) createSessionState(ctx context.Context, token *oauth2.Token) (*sessions.SessionState, error) {
 	rawIDToken, ok := token.Extra("id_token").(string)
 	if !ok {
 		return nil, fmt.Errorf("token response did not contain an id_token")
@ -122,7 +122,7 @@ func (p *OIDCProvider) createSessionState(ctx context.Context, token *oauth2.Tok
 		return nil, fmt.Errorf("email in id_token (%s) isn't verified", claims.Email)
 	}

-	return &SessionState{
+	return &sessions.SessionState{
 		AccessToken:  token.AccessToken,
 		IDToken:      rawIDToken,
 		RefreshToken: token.RefreshToken,
@ -133,7 +133,7 @@ func (p *OIDCProvider) createSessionState(ctx context.Context, token *oauth2.Tok
 }

 // ValidateSessionState checks that the session's IDToken is still valid
-func (p *OIDCProvider) ValidateSessionState(s *SessionState) bool {
+func (p *OIDCProvider) ValidateSessionState(s *sessions.SessionState) bool {
 	ctx := context.Background()
 	_, err := p.Verifier.Verify(ctx, s.IDToken)
 	if err != nil {
--- a/providers/provider_default.go
+++ b/providers/provider_default.go
@ -10,10 +10,11 @@ import (
 	"net/url"

 	"github.com/pusher/oauth2_proxy/cookie"
+	"github.com/pusher/oauth2_proxy/pkg/apis/sessions"
 )

 // Redeem provides a default implementation of the OAuth2 token redemption process
-func (p *ProviderData) Redeem(redirectURL, code string) (s *SessionState, err error) {
+func (p *ProviderData) Redeem(redirectURL, code string) (s *sessions.SessionState, err error) {
 	if code == "" {
 		err = errors.New("missing code")
 		return
@ -59,7 +60,7 @@ func (p *ProviderData) Redeem(redirectURL, code string) (s *SessionState, err er
 	}
 	err = json.Unmarshal(body, &jsonResponse)
 	if err == nil {
-		s = &SessionState{
+		s = &sessions.SessionState{
 			AccessToken: jsonResponse.AccessToken,
 		}
 		return
@ -71,7 +72,7 @@ func (p *ProviderData) Redeem(redirectURL, code string) (s *SessionState, err er
 		return
 	}
 	if a := v.Get("access_token"); a != "" {
-		s = &SessionState{AccessToken: a}
+		s = &sessions.SessionState{AccessToken: a}
 	} else {
 		err = fmt.Errorf("no access token found %s", body)
 	}
@ -94,22 +95,22 @@ func (p *ProviderData) GetLoginURL(redirectURI, state string) string {
 }

 // CookieForSession serializes a session state for storage in a cookie
-func (p *ProviderData) CookieForSession(s *SessionState, c *cookie.Cipher) (string, error) {
+func (p *ProviderData) CookieForSession(s *sessions.SessionState, c *cookie.Cipher) (string, error) {
 	return s.EncodeSessionState(c)
 }

 // SessionFromCookie deserializes a session from a cookie value
-func (p *ProviderData) SessionFromCookie(v string, c *cookie.Cipher) (s *SessionState, err error) {
-	return DecodeSessionState(v, c)
+func (p *ProviderData) SessionFromCookie(v string, c *cookie.Cipher) (s *sessions.SessionState, err error) {
+	return sessions.DecodeSessionState(v, c)
 }

 // GetEmailAddress returns the Account email address
-func (p *ProviderData) GetEmailAddress(s *SessionState) (string, error) {
+func (p *ProviderData) GetEmailAddress(s *sessions.SessionState) (string, error) {
 	return "", errors.New("not implemented")
 }

 // GetUserName returns the Account username
-func (p *ProviderData) GetUserName(s *SessionState) (string, error) {
+func (p *ProviderData) GetUserName(s *sessions.SessionState) (string, error) {
 	return "", errors.New("not implemented")
 }

@ -120,12 +121,12 @@ func (p *ProviderData) ValidateGroup(email string) bool {
 }

 // ValidateSessionState validates the AccessToken
-func (p *ProviderData) ValidateSessionState(s *SessionState) bool {
+func (p *ProviderData) ValidateSessionState(s *sessions.SessionState) bool {
 	return validateToken(p, s.AccessToken, nil)
 }

 // RefreshSessionIfNeeded should refresh the user's session if required and
 // do nothing if a refresh is not required
-func (p *ProviderData) RefreshSessionIfNeeded(s *SessionState) (bool, error) {
+func (p *ProviderData) RefreshSessionIfNeeded(s *sessions.SessionState) (bool, error) {
 	return false, nil
 }
--- a/providers/provider_default_test.go
+++ b/providers/provider_default_test.go
@ -4,12 +4,13 @@ import (
 	"testing"
 	"time"

+	"github.com/pusher/oauth2_proxy/pkg/apis/sessions"
 	"github.com/stretchr/testify/assert"
 )

 func TestRefresh(t *testing.T) {
 	p := &ProviderData{}
-	refreshed, err := p.RefreshSessionIfNeeded(&SessionState{
+	refreshed, err := p.RefreshSessionIfNeeded(&sessions.SessionState{
 		ExpiresOn: time.Now().Add(time.Duration(-11) * time.Minute),
 	})
 	assert.Equal(t, false, refreshed)
--- a/providers/providers.go
+++ b/providers/providers.go
@ -2,20 +2,21 @@ package providers

 import (
 	"github.com/pusher/oauth2_proxy/cookie"
+	"github.com/pusher/oauth2_proxy/pkg/apis/sessions"
 )

 // Provider represents an upstream identity provider implementation
 type Provider interface {
 	Data() *ProviderData
-	GetEmailAddress(*SessionState) (string, error)
-	GetUserName(*SessionState) (string, error)
-	Redeem(string, string) (*SessionState, error)
+	GetEmailAddress(*sessions.SessionState) (string, error)
+	GetUserName(*sessions.SessionState) (string, error)
+	Redeem(string, string) (*sessions.SessionState, error)
 	ValidateGroup(string) bool
-	ValidateSessionState(*SessionState) bool
+	ValidateSessionState(*sessions.SessionState) bool
 	GetLoginURL(redirectURI, finalRedirect string) string
-	RefreshSessionIfNeeded(*SessionState) (bool, error)
-	SessionFromCookie(string, *cookie.Cipher) (*SessionState, error)
-	CookieForSession(*SessionState, *cookie.Cipher) (string, error)
+	RefreshSessionIfNeeded(*sessions.SessionState) (bool, error)
+	SessionFromCookie(string, *cookie.Cipher) (*sessions.SessionState, error)
+	CookieForSession(*sessions.SessionState, *cookie.Cipher) (string, error)
 }

 // New provides a new Provider based on the configured provider string