Merge branch 'master' into add_adfs_provider

2019-08-13 21:43:32 +01:00 · 2019-08-13 21:43:32 +01:00 · 322bf9f10e
commit 322bf9f10e
parent 7872309e28 9240538939
16 changed files with 585 additions and 225 deletions
--- a/.github/CODEOWNERS
+++ b/.github/CODEOWNERS
@ -1,6 +1,6 @@
-# Default owner should be a Pusher cloud-team member unless overridden by later
-# rules in this file
-* @pusher/cloud-team
+# Default owner should be a Pusher cloud-team member or another maintainer
+# unless overridden by later rules in this file
+* @pusher/cloud-team @syscll @steakunderscore

 # login.gov provider
 # Note:  If @timothy-spencer terms out of his appointment, your best bet
--- a/.travis.yml
+++ b/.travis.yml
@ -3,10 +3,8 @@ go:
  - 1.12.x
 install:
  # Fetch dependencies
-  - wget -O dep https://github.com/golang/dep/releases/download/v0.5.0/dep-linux-amd64
-  - chmod +x dep
-  - mv dep $GOPATH/bin/dep
  - curl -sfL https://install.goreleaser.com/github.com/golangci/golangci-lint.sh | sh -s -- -b $GOPATH/bin v1.17.1
+  - GO111MODULE=on go mod download
 script:
  - ./configure && make test
 sudo: false
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@ -2,6 +2,11 @@

 ## Breaking Changes

+- [#231](https://github.com/pusher/oauth2_proxy/pull/231) Rework GitLab provider (@Overv)
+  - This PR changes the configuration options for the GitLab provider to use
+  a self-hosted instance. You now need to specify a `-oidc-issuer-url` rather than
+  explicit `-login-url`, `-redeem-url` and `-validate-url` parameters.
+
 - [#186](https://github.com/pusher/oauth2_proxy/pull/186) Make config consistent
  - This PR changes configuration options so that all flags have a config counterpart
  of the same name but with underscores (`_`) in place of hyphens (`-`).
@ -31,18 +36,21 @@

 ## Changes since v3.2.0

- [#178](https://github.com/pusher/outh2_proxy/pull/178) Add Silence Ping Logging and Exclude Logging Paths flags (@kskewes)
- [#209](https://github.com/pusher/outh2_proxy/pull/209) Improve docker build caching of layers (@dekimsey)
+- [#234](https://github.com/pusher/oauth2_proxy/pull/234) Added option `-ssl-upstream-insecure-skip-validation` to skip validation of upstream SSL certificates (@jansinger)
+- [#224](https://github.com/pusher/oauth2_proxy/pull/224) Check Google group membership using hasMember to support nested groups and external users (@jpalpant)
+- [#231](https://github.com/pusher/oauth2_proxy/pull/231) Add optional group membership and email domain checks to the GitLab provider (@Overv)
+- [#178](https://github.com/pusher/oauth2_proxy/pull/178) Add Silence Ping Logging and Exclude Logging Paths flags (@kskewes)
+- [#209](https://github.com/pusher/oauth2_proxy/pull/209) Improve docker build caching of layers (@dekimsey)
 - [#186](https://github.com/pusher/oauth2_proxy/pull/186) Make config consistent (@JoelSpeed)
 - [#187](https://github.com/pusher/oauth2_proxy/pull/187) Move root packages to pkg folder (@JoelSpeed)
 - [#65](https://github.com/pusher/oauth2_proxy/pull/65) Improvements to authenticate requests with a JWT bearer token in the `Authorization` header via
  the `-skip-jwt-bearer-token` options.
  - Additional verifiers can be configured via the `-extra-jwt-issuers` flag if the JWT issuers is either an OpenID provider or has a JWKS URL
  (e.g. `https://example.com/.well-known/jwks.json`).
- [#180](https://github.com/pusher/outh2_proxy/pull/180) Minor refactor of core proxying path (@aeijdenberg).
- [#175](https://github.com/pusher/outh2_proxy/pull/175) Bump go-oidc to v2.0.0 (@aeijdenberg).
+- [#180](https://github.com/pusher/oauth2_proxy/pull/180) Minor refactor of core proxying path (@aeijdenberg).
+- [#175](https://github.com/pusher/oauth2_proxy/pull/175) Bump go-oidc to v2.0.0 (@aeijdenberg).
  - Includes fix for potential signature checking issue when OIDC discovery is skipped.
- [#155](https://github.com/pusher/outh2_proxy/pull/155) Add RedisSessionStore implementation (@brianv0, @JoelSpeed)
+- [#155](https://github.com/pusher/oauth2_proxy/pull/155) Add RedisSessionStore implementation (@brianv0, @JoelSpeed)
  - Implement flags to configure the redis session store
    - `-session-store-type=redis` Sets the store type to redis
    - `-redis-connection-url` Sets the Redis connection URL
@ -52,10 +60,10 @@
  - Introduces the concept of a session ticket. Tickets are composed of the cookie name, a session ID, and a secret.
  - Redis Sessions are stored encrypted with a per-session secret
  - Added tests for server based session stores
- [#168](https://github.com/pusher/outh2_proxy/pull/168) Drop Go 1.11 support in Travis (@JoelSpeed)
- [#169](https://github.com/pusher/outh2_proxy/pull/169) Update Alpine to 3.9 (@kskewes)
- [#148](https://github.com/pusher/outh2_proxy/pull/148) Implement SessionStore interface within proxy (@JoelSpeed)
- [#147](https://github.com/pusher/outh2_proxy/pull/147) Add SessionStore interfaces and initial implementation (@JoelSpeed)
+- [#168](https://github.com/pusher/oauth2_proxy/pull/168) Drop Go 1.11 support in Travis (@JoelSpeed)
+- [#169](https://github.com/pusher/oauth2_proxy/pull/169) Update Alpine to 3.9 (@kskewes)
+- [#148](https://github.com/pusher/oauth2_proxy/pull/148) Implement SessionStore interface within proxy (@JoelSpeed)
+- [#147](https://github.com/pusher/oauth2_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
@ -83,12 +91,13 @@
 - [#185](https://github.com/pusher/oauth2_proxy/pull/185) Fix an unsupported protocol scheme error during token validation when using the Azure provider (@jonas)
 - [#141](https://github.com/pusher/oauth2_proxy/pull/141) Check google group membership based on email address (@bchess)
  - Google Group membership is additionally checked via email address, allowing users outside a GSuite domain to be authorized.
- [#195](https://github.com/pusher/outh2_proxy/pull/195) Add `-banner` flag for overriding the banner line that is displayed (@steakunderscore)
- [#198](https://github.com/pusher/outh2_proxy/pull/198) Switch from gometalinter to golangci-lint (@steakunderscore)
+- [#195](https://github.com/pusher/oauth2_proxy/pull/195) Add `-banner` flag for overriding the banner line that is displayed (@steakunderscore)
+- [#198](https://github.com/pusher/oauth2_proxy/pull/198) Switch from gometalinter to golangci-lint (@steakunderscore)
 - [#159](https://github.com/pusher/oauth2_proxy/pull/159) Add option to skip the OIDC provider verified email check: `--insecure-oidc-allow-unverified-email`
 - [#210](https://github.com/pusher/oauth2_proxy/pull/210) Update base image from Alpine 3.9 to 3.10 (@steakunderscore)
 - [#211](https://github.com/pusher/oauth2_proxy/pull/211) Switch from dep to go modules (@steakunderscore)
 - [#221](https://github.com/pusher/oauth2_proxy/pull/221) Add ADFS as new OAuth2 provider (@MaxFedotov)
+- [#145](https://github.com/pusher/oauth2_proxy/pull/145) Add support for OIDC UserInfo endpoint email verification (@rtluckie)

 # v3.2.0

--- a/3
+++ b/3
@ -0,0 +1,3 @@
+Joel Speed <joel.speed@hotmail.co.uk> (@JoelSpeed)
+Dan Bond (@syscll)
+Henry Jenkins <henry@henryjenkins.name> (@steakunderscore)
--- a/README.md
+++ b/README.md
@ -38,6 +38,10 @@ Read the docs on our [Docs site](https://pusher.github.io/oauth2_proxy).

 ![OAuth2 Proxy Architecture](https://cloud.githubusercontent.com/assets/45028/8027702/bd040b7a-0d6a-11e5-85b9-f8d953d04f39.png)

+## Getting Involved
+
+If you would like to reach out to the maintainers, come talk to us in the `#oauth2_proxy` channel in the [Gophers slack](http://gophers.slack.com/).
+
 ## Contributing

 Please see our [Contributing](CONTRIBUTING.md) guidelines.
--- a/docs/2_auth.md
+++ b/docs/2_auth.md
@ -103,13 +103,15 @@ If you are using GitHub enterprise, make sure you set the following to the appro

 ### GitLab Auth Provider

-Whether you are using GitLab.com or self-hosting GitLab, follow [these steps to add an application](http://doc.gitlab.com/ce/integration/oauth_provider.html)
+Whether you are using GitLab.com or self-hosting GitLab, follow [these steps to add an application](http://doc.gitlab.com/ce/integration/oauth_provider.html). Make sure to enable at least the `openid`, `profile` and `email` scopes.
+
+Restricting by group membership is possible with the following option:
+
+    -gitlab-group="": restrict logins to members of any of these groups (slug), separated by a comma

 If you are using self-hosted GitLab, make sure you set the following to the appropriate URL:

-    -login-url="<your gitlab url>/oauth/authorize"
-    -redeem-url="<your gitlab url>/oauth/token"
-    -validate-url="<your gitlab url>/api/v4/user"
+    -oidc-issuer-url="<your gitlab url>"

 ### LinkedIn Auth Provider

@ -144,6 +146,56 @@ OpenID Connect is a spec for OAUTH 2.0 + identity that is implemented by many ma
    -cookie-secure=false
    -email-domain example.com

+The OpenID Connect Provider (OIDC) can also be used to connect to other Identity Providers such as Okta. To configure the OIDC provider for Okta, perform
+the following steps:
+
+#### Configuring the OIDC Provider with Okta
+
+1. Log in to Okta using an administrative account. It is suggested you try this in preview first, `example.oktapreview.com`
+2. (OPTIONAL) If you want to configure authorization scopes and claims to be passed on to multiple applications,
+you may wish to configure an authorization server for each application. Otherwise, the provided `default` will work.
+* Navigate to **Security** then select **API**
+* Click **Add Authorization Server**, if this option is not available you may require an additional license for a custom authorization server.
+* Fill out the **Name** with something to describe the application you are protecting. e.g. 'Example App'.
+* For **Audience**, pick the URL of the application you wish to protect: https://example.corp.com
+* Fill out a **Description**
+* Add any **Access Policies** you wish to configure to limit application access.
+* The default settings will work for other options.
+[See Okta documentation for more information on Authorization Servers](https://developer.okta.com/docs/guides/customize-authz-server/overview/)
+3. Navigate to **Applications** then select **Add Application**.
+* Select **Web** for the **Platform** setting.
+* Select **OpenID Connect** and click **Create**
+* Pick an **Application Name** such as `Example App`.
+* Set the **Login redirect URI** to `https://example.corp.com`.
+* Under **General** set the **Allowed grant types** to `Authorization Code` and `Refresh Token`.
+* Leave the rest as default, taking note of the `Client ID` and `Client Secret`.
+* Under **Assignments** select the users or groups you wish to access your application.
+4. Create a configuration file like the following:
+
+```
+provider = "oidc"
+redirect_url = "https://example.corp.com"
+oidc_issuer_url = "https://corp.okta.com/oauth2/abCd1234"
+upstreams = [
+    "https://example.corp.com"
+]
+email_domains = [
+    "corp.com"
+]
+client_id = "XXXXX"
+client_secret = "YYYYY"
+pass_access_token = true
+cookie_secret = "ZZZZZ"
+skip_provider_button = true
+```
+
+The `oidc_issuer_url` is based on URL from your **Authorization Server**'s **Issuer** field in step 2, or simply https://corp.okta.com
+The `client_id` and `client_secret` are configured in the application settings.
+Generate a unique `client_secret` to encrypt the cookie.
+
+Then you can start the oauth2_proxy with `./oauth2_proxy -config /etc/example.cfg`
+
+
 ### login.gov Provider

 login.gov is an OIDC provider for the US Government.
--- a/docs/configuration/configuration.md
+++ b/docs/configuration/configuration.md
@ -14,7 +14,7 @@ To generate a strong cookie secret use `python -c 'import os,base64; print base6

 ### Config File

-An example [oauth2_proxy.cfg](contrib/oauth2_proxy.cfg.example) config file is in the contrib directory. It can be used by specifying `-config=/etc/oauth2_proxy.cfg`
+An example [oauth2_proxy.cfg](https://github.com/pusher/oauth2_proxy/blob/master/contrib/oauth2_proxy.cfg.example) config file is in the contrib directory. It can be used by specifying `-config=/etc/oauth2_proxy.cfg`

 ### Command Line Options

@ -49,6 +49,7 @@ Usage of oauth2_proxy:
  -gcp-healthchecks: will enable /liveness_check, /readiness_check, and / (with the proper user-agent) endpoints that will make it work well with GCP App Engine and GKE Ingresses (default false)
  -github-org string: restrict logins to members of this organisation
  -github-team string: restrict logins to members of any of these teams (slug), separated by a comma
+  -gitlab-group string: restrict logins to members of any of these groups (slug), separated by a comma
  -google-admin-email string: the google admin to impersonate for api calls
  -google-group value: restrict logins to members of this google group (may be given multiple times).
  -google-service-account-json string: the path to the service account json credentials
@ -81,8 +82,8 @@ Usage of oauth2_proxy:
  -redeem-url string: Token redemption endpoint
  -redirect-url string: the OAuth Redirect URL. ie: "https://internalapp.yourcompany.com/oauth2/callback"
  -redis-connection-url string: URL of redis server for redis session storage (eg: redis://HOST[:PORT])
-  -redis-sentinel-master-name string: Redis sentinel master name. Used in conjuction with --redis-use-sentinel
-  -redis-sentinel-connection-urls: List of Redis sentinel conneciton URLs (eg redis://HOST[:PORT]). Used in conjuction with --redis-use-sentinel
+  -redis-sentinel-master-name string: Redis sentinel master name. Used in conjunction with --redis-use-sentinel
+  -redis-sentinel-connection-urls: List of Redis sentinel connection URLs (eg redis://HOST[:PORT]). Used in conjunction with --redis-use-sentinel
  -redis-use-sentinel: Connect to redis via sentinels. Must set --redis-sentinel-master-name and --redis-sentinel-connection-urls to use this feature (default: false)
  -request-logging: Log requests to stdout (default true)
  -request-logging-format: Template for request log lines (see "Logging Configuration" paragraph below)
@ -98,7 +99,8 @@ Usage of oauth2_proxy:
  -skip-jwt-bearer-tokens: will skip requests that have verified JWT bearer tokens
  -skip-oidc-discovery: bypass OIDC endpoint discovery. login-url, redeem-url and oidc-jwks-url must be configured in this case
  -skip-provider-button: will skip sign-in-page to directly reach the next step: oauth/start
-  -ssl-insecure-skip-verify: skip validation of certificates presented when using HTTPS
+  -ssl-insecure-skip-verify: skip validation of certificates presented when using HTTPS providers
+  -ssl-upstream-insecure-skip-verify: skip validation of certificates presented when using HTTPS upstreams
  -standard-logging: Log standard runtime information (default true)
  -standard-logging-format string: Template for standard log lines (see "Logging Configuration" paragraph below)
  -tls-cert-file string: path to certificate file
--- a/main.go
+++ b/main.go
@ -47,7 +47,8 @@ func main() {
 	flagSet.Var(&skipAuthRegex, "skip-auth-regex", "bypass authentication for requests path's that match (may be given multiple times)")
 	flagSet.Bool("skip-provider-button", false, "will skip sign-in-page to directly reach the next step: oauth/start")
 	flagSet.Bool("skip-auth-preflight", false, "will skip authentication for OPTIONS requests")
-	flagSet.Bool("ssl-insecure-skip-verify", false, "skip validation of certificates presented when using HTTPS")
+	flagSet.Bool("ssl-insecure-skip-verify", false, "skip validation of certificates presented when using HTTPS providers")
+	flagSet.Bool("ssl-upstream-insecure-skip-verify", false, "skip validation of certificates presented when using HTTPS upstreams")
 	flagSet.Duration("flush-interval", time.Duration(1)*time.Second, "period between response flushing when streaming responses")
 	flagSet.Bool("skip-jwt-bearer-tokens", false, "will skip requests that have verified JWT bearer tokens (default false)")
 	flagSet.Var(&jwtIssuers, "extra-jwt-issuers", "if skip-jwt-bearer-tokens is set, a list of extra JWT issuer=audience pairs (where the issuer URL has a .well-known/openid-configuration or a .well-known/jwks.json)")
@ -57,6 +58,7 @@ func main() {
 	flagSet.String("azure-tenant", "common", "go to a tenant-specific or common (tenant-independent) endpoint.")
 	flagSet.String("github-org", "", "restrict logins to members of this organisation")
 	flagSet.String("github-team", "", "restrict logins to members of this team")
+	flagSet.String("gitlab-group", "", "restrict logins to members of this group")
 	flagSet.Var(&googleGroups, "google-group", "restrict logins to members of this google group (may be given multiple times).")
 	flagSet.String("google-admin-email", "", "the google admin to impersonate for api calls")
 	flagSet.String("google-service-account-json", "", "the path to the service account json credentials")
@ -84,8 +86,8 @@ func main() {
 	flagSet.String("session-store-type", "cookie", "the session storage provider to use")
 	flagSet.String("redis-connection-url", "", "URL of redis server for redis session storage (eg: redis://HOST[:PORT])")
 	flagSet.Bool("redis-use-sentinel", false, "Connect to redis via sentinels. Must set --redis-sentinel-master-name and --redis-sentinel-connection-urls to use this feature")
-	flagSet.String("redis-sentinel-master-name", "", "Redis sentinel master name. Used in conjuction with --redis-use-sentinel")
-	flagSet.Var(&redisSentinelConnectionURLs, "redis-sentinel-connection-urls", "List of Redis sentinel connection URLs (eg redis://HOST[:PORT]). Used in conjuction with --redis-use-sentinel")
+	flagSet.String("redis-sentinel-master-name", "", "Redis sentinel master name. Used in conjunction with --redis-use-sentinel")
+	flagSet.Var(&redisSentinelConnectionURLs, "redis-sentinel-connection-urls", "List of Redis sentinel connection URLs (eg redis://HOST[:PORT]). Used in conjunction with --redis-use-sentinel")

 	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")
--- a/oauthproxy.go
+++ b/oauthproxy.go
@ -2,6 +2,7 @@ package main

 import (
 	"context"
+	"crypto/tls"
 	b64 "encoding/base64"
 	"errors"
 	"fmt"
@ -128,9 +129,14 @@ func (u *UpstreamProxy) ServeHTTP(w http.ResponseWriter, r *http.Request) {

 // NewReverseProxy creates a new reverse proxy for proxying requests to upstream
 // servers
-func NewReverseProxy(target *url.URL, flushInterval time.Duration) (proxy *httputil.ReverseProxy) {
+func NewReverseProxy(target *url.URL, opts *Options) (proxy *httputil.ReverseProxy) {
 	proxy = httputil.NewSingleHostReverseProxy(target)
-	proxy.FlushInterval = flushInterval
+	proxy.FlushInterval = opts.FlushInterval
+	if opts.SSLUpstreamInsecureSkipVerify {
+		proxy.Transport = &http.Transport{
+			TLSClientConfig: &tls.Config{InsecureSkipVerify: true},
+		}
+	}
 	return proxy
 }

@ -163,7 +169,7 @@ func NewFileServer(path string, filesystemPath string) (proxy http.Handler) {
 // NewWebSocketOrRestReverseProxy creates a reverse proxy for REST or websocket based on url
 func NewWebSocketOrRestReverseProxy(u *url.URL, opts *Options, auth hmacauth.HmacAuth) http.Handler {
 	u.Path = ""
-	proxy := NewReverseProxy(u, opts.FlushInterval)
+	proxy := NewReverseProxy(u, opts)
 	if !opts.PassHostHeader {
 		setProxyUpstreamHostHeader(proxy, u)
 	} else {
@ -892,7 +898,7 @@ func isAjax(req *http.Request) bool {
 	return false
 }

-// ErrorJSON returns the error code witht an application/json mime type
+// ErrorJSON returns the error code with an application/json mime type
 func (p *OAuthProxy) ErrorJSON(rw http.ResponseWriter, code int) {
 	rw.Header().Set("Content-Type", applicationJSON)
 	rw.WriteHeader(code)
--- a/oauthproxy_test.go
+++ b/oauthproxy_test.go
@ -122,7 +122,7 @@ func TestNewReverseProxy(t *testing.T) {
 	backendHost := net.JoinHostPort(backendHostname, backendPort)
 	proxyURL, _ := url.Parse(backendURL.Scheme + "://" + backendHost + "/")

-	proxyHandler := NewReverseProxy(proxyURL, time.Second)
+	proxyHandler := NewReverseProxy(proxyURL, &Options{FlushInterval: time.Second})
 	setProxyUpstreamHostHeader(proxyHandler, proxyURL)
 	frontend := httptest.NewServer(proxyHandler)
 	defer frontend.Close()
@ -144,7 +144,7 @@ func TestEncodedSlashes(t *testing.T) {
 	defer backend.Close()

 	b, _ := url.Parse(backend.URL)
-	proxyHandler := NewReverseProxy(b, time.Second)
+	proxyHandler := NewReverseProxy(b, &Options{FlushInterval: time.Second})
 	setProxyDirector(proxyHandler)
 	frontend := httptest.NewServer(proxyHandler)
 	defer frontend.Close()
--- a/options.go
+++ b/options.go
@ -46,6 +46,7 @@ type Options struct {
 	WhitelistDomains         []string `flag:"whitelist-domain" cfg:"whitelist_domains" env:"OAUTH2_PROXY_WHITELIST_DOMAINS"`
 	GitHubOrg                string   `flag:"github-org" cfg:"github_org" env:"OAUTH2_PROXY_GITHUB_ORG"`
 	GitHubTeam               string   `flag:"github-team" cfg:"github_team" env:"OAUTH2_PROXY_GITHUB_TEAM"`
+	GitLabGroup              string   `flag:"gitlab-group" cfg:"gitlab_group" env:"OAUTH2_PROXY_GITLAB_GROUP"`
 	GoogleGroups             []string `flag:"google-group" cfg:"google_group" env:"OAUTH2_PROXY_GOOGLE_GROUPS"`
 	GoogleAdminEmail         string   `flag:"google-admin-email" cfg:"google_admin_email" env:"OAUTH2_PROXY_GOOGLE_ADMIN_EMAIL"`
 	GoogleServiceAccountJSON string   `flag:"google-service-account-json" cfg:"google_service_account_json" env:"OAUTH2_PROXY_GOOGLE_SERVICE_ACCOUNT_JSON"`
@ -61,22 +62,23 @@ type Options struct {
 	// 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"`
-	SkipJwtBearerTokens   bool          `flag:"skip-jwt-bearer-tokens" cfg:"skip_jwt_bearer_tokens" env:"OAUTH2_PROXY_SKIP_JWT_BEARER_TOKENS"`
-	ExtraJwtIssuers       []string      `flag:"extra-jwt-issuers" cfg:"extra_jwt_issuers" env:"OAUTH2_PROXY_EXTRA_JWT_ISSUERS"`
-	PassBasicAuth         bool          `flag:"pass-basic-auth" cfg:"pass_basic_auth" env:"OAUTH2_PROXY_PASS_BASIC_AUTH"`
-	BasicAuthPassword     string        `flag:"basic-auth-password" cfg:"basic_auth_password" env:"OAUTH2_PROXY_BASIC_AUTH_PASSWORD"`
-	PassAccessToken       bool          `flag:"pass-access-token" cfg:"pass_access_token" env:"OAUTH2_PROXY_PASS_ACCESS_TOKEN"`
-	PassHostHeader        bool          `flag:"pass-host-header" cfg:"pass_host_header" env:"OAUTH2_PROXY_PASS_HOST_HEADER"`
-	SkipProviderButton    bool          `flag:"skip-provider-button" cfg:"skip_provider_button" env:"OAUTH2_PROXY_SKIP_PROVIDER_BUTTON"`
-	PassUserHeaders       bool          `flag:"pass-user-headers" cfg:"pass_user_headers" env:"OAUTH2_PROXY_PASS_USER_HEADERS"`
-	SSLInsecureSkipVerify bool          `flag:"ssl-insecure-skip-verify" cfg:"ssl_insecure_skip_verify" env:"OAUTH2_PROXY_SSL_INSECURE_SKIP_VERIFY"`
-	SetXAuthRequest       bool          `flag:"set-xauthrequest" cfg:"set_xauthrequest" env:"OAUTH2_PROXY_SET_XAUTHREQUEST"`
-	SetAuthorization      bool          `flag:"set-authorization-header" cfg:"set_authorization_header" env:"OAUTH2_PROXY_SET_AUTHORIZATION_HEADER"`
-	PassAuthorization     bool          `flag:"pass-authorization-header" cfg:"pass_authorization_header" env:"OAUTH2_PROXY_PASS_AUTHORIZATION_HEADER"`
-	SkipAuthPreflight     bool          `flag:"skip-auth-preflight" cfg:"skip_auth_preflight" env:"OAUTH2_PROXY_SKIP_AUTH_PREFLIGHT"`
-	FlushInterval         time.Duration `flag:"flush-interval" cfg:"flush_interval" env:"OAUTH2_PROXY_FLUSH_INTERVAL"`
+	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"`
+	SkipJwtBearerTokens           bool          `flag:"skip-jwt-bearer-tokens" cfg:"skip_jwt_bearer_tokens" env:"OAUTH2_PROXY_SKIP_JWT_BEARER_TOKENS"`
+	ExtraJwtIssuers               []string      `flag:"extra-jwt-issuers" cfg:"extra_jwt_issuers" env:"OAUTH2_PROXY_EXTRA_JWT_ISSUERS"`
+	PassBasicAuth                 bool          `flag:"pass-basic-auth" cfg:"pass_basic_auth" env:"OAUTH2_PROXY_PASS_BASIC_AUTH"`
+	BasicAuthPassword             string        `flag:"basic-auth-password" cfg:"basic_auth_password" env:"OAUTH2_PROXY_BASIC_AUTH_PASSWORD"`
+	PassAccessToken               bool          `flag:"pass-access-token" cfg:"pass_access_token" env:"OAUTH2_PROXY_PASS_ACCESS_TOKEN"`
+	PassHostHeader                bool          `flag:"pass-host-header" cfg:"pass_host_header" env:"OAUTH2_PROXY_PASS_HOST_HEADER"`
+	SkipProviderButton            bool          `flag:"skip-provider-button" cfg:"skip_provider_button" env:"OAUTH2_PROXY_SKIP_PROVIDER_BUTTON"`
+	PassUserHeaders               bool          `flag:"pass-user-headers" cfg:"pass_user_headers" env:"OAUTH2_PROXY_PASS_USER_HEADERS"`
+	SSLInsecureSkipVerify         bool          `flag:"ssl-insecure-skip-verify" cfg:"ssl_insecure_skip_verify" env:"OAUTH2_PROXY_SSL_INSECURE_SKIP_VERIFY"`
+	SSLUpstreamInsecureSkipVerify bool          `flag:"ssl-upstream-insecure-skip-verify" cfg:"ssl_upstream_insecure_skip_verify" env:"OAUTH2_PROXY_SSL_UPSTREAM_INSECURE_SKIP_VERIFY"`
+	SetXAuthRequest               bool          `flag:"set-xauthrequest" cfg:"set_xauthrequest" env:"OAUTH2_PROXY_SET_XAUTHREQUEST"`
+	SetAuthorization              bool          `flag:"set-authorization-header" cfg:"set_authorization_header" env:"OAUTH2_PROXY_SET_AUTHORIZATION_HEADER"`
+	PassAuthorization             bool          `flag:"pass-authorization-header" cfg:"pass_authorization_header" env:"OAUTH2_PROXY_PASS_AUTHORIZATION_HEADER"`
+	SkipAuthPreflight             bool          `flag:"skip-auth-preflight" cfg:"skip_auth_preflight" env:"OAUTH2_PROXY_SKIP_AUTH_PREFLIGHT"`
+	FlushInterval                 time.Duration `flag:"flush-interval" cfg:"flush_interval" env:"OAUTH2_PROXY_FLUSH_INTERVAL"`

 	// These options allow for other providers besides Google, with
 	// potential overrides.
@ -410,6 +412,29 @@ func parseProviderInfo(o *Options, msgs []string) []string {
 		} else {
 			p.Verifier = o.oidcVerifier
 		}
+	case *providers.GitLabProvider:
+		p.AllowUnverifiedEmail = o.InsecureOIDCAllowUnverifiedEmail
+		p.Group = o.GitLabGroup
+		p.EmailDomains = o.EmailDomains
+
+		if o.oidcVerifier != nil {
+			p.Verifier = o.oidcVerifier
+		} else {
+			// Initialize with default verifier for gitlab.com
+			ctx := context.Background()
+
+			provider, err := oidc.NewProvider(ctx, "https://gitlab.com")
+			if err != nil {
+				msgs = append(msgs, "failed to initialize oidc provider for gitlab.com")
+			} else {
+				p.Verifier = provider.Verifier(&oidc.Config{
+					ClientID: o.ClientID,
+				})
+
+				p.LoginURL, msgs = parseURL(provider.Endpoint().AuthURL, "login", msgs)
+				p.RedeemURL, msgs = parseURL(provider.Endpoint().TokenURL, "redeem", msgs)
+			}
+		}
 	case *providers.LoginGovProvider:
 		p.AcrValues = o.AcrValues
 		p.PubJWKURL, msgs = parseURL(o.PubJWKURL, "pubjwk", msgs)
--- a/providers/gitlab.go
+++ b/providers/gitlab.go
@ -1,62 +1,258 @@
 package providers

 import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
 	"net/http"
-	"net/url"
+	"strings"
+	"time"

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

-// GitLabProvider represents an GitLab based Identity Provider
+// GitLabProvider represents a GitLab based Identity Provider
 type GitLabProvider struct {
 	*ProviderData
+
+	Group        string
+	EmailDomains []string
+
+	Verifier             *oidc.IDTokenVerifier
+	AllowUnverifiedEmail bool
 }

 // NewGitLabProvider initiates a new GitLabProvider
 func NewGitLabProvider(p *ProviderData) *GitLabProvider {
 	p.ProviderName = "GitLab"
-	if p.LoginURL == nil || p.LoginURL.String() == "" {
-		p.LoginURL = &url.URL{
-			Scheme: "https",
-			Host:   "gitlab.com",
-			Path:   "/oauth/authorize",
-		}
-	}
-	if p.RedeemURL == nil || p.RedeemURL.String() == "" {
-		p.RedeemURL = &url.URL{
-			Scheme: "https",
-			Host:   "gitlab.com",
-			Path:   "/oauth/token",
-		}
-	}
-	if p.ValidateURL == nil || p.ValidateURL.String() == "" {
-		p.ValidateURL = &url.URL{
-			Scheme: "https",
-			Host:   "gitlab.com",
-			Path:   "/api/v4/user",
-		}
-	}
+
 	if p.Scope == "" {
-		p.Scope = "read_user"
+		p.Scope = "openid email"
 	}
+
 	return &GitLabProvider{ProviderData: p}
 }

+// Redeem exchanges the OAuth2 authentication token for an ID token
+func (p *GitLabProvider) Redeem(redirectURL, code string) (s *sessions.SessionState, err error) {
+	ctx := context.Background()
+	c := oauth2.Config{
+		ClientID:     p.ClientID,
+		ClientSecret: p.ClientSecret,
+		Endpoint: oauth2.Endpoint{
+			TokenURL: p.RedeemURL.String(),
+		},
+		RedirectURL: redirectURL,
+	}
+	token, err := c.Exchange(ctx, code)
+	if err != nil {
+		return nil, fmt.Errorf("token exchange: %v", err)
+	}
+	s, err = p.createSessionState(ctx, token)
+	if err != nil {
+		return nil, fmt.Errorf("unable to update session: %v", err)
+	}
+	return
+}
+
+// RefreshSessionIfNeeded checks if the session has expired and uses the
+// RefreshToken to fetch a new ID token if required
+func (p *GitLabProvider) RefreshSessionIfNeeded(s *sessions.SessionState) (bool, error) {
+	if s == nil || s.ExpiresOn.After(time.Now()) || s.RefreshToken == "" {
+		return false, nil
+	}
+
+	origExpiration := s.ExpiresOn
+
+	err := p.redeemRefreshToken(s)
+	if err != nil {
+		return false, fmt.Errorf("unable to redeem refresh token: %v", err)
+	}
+
+	fmt.Printf("refreshed id token %s (expired on %s)\n", s, origExpiration)
+	return true, nil
+}
+
+func (p *GitLabProvider) redeemRefreshToken(s *sessions.SessionState) (err error) {
+	c := oauth2.Config{
+		ClientID:     p.ClientID,
+		ClientSecret: p.ClientSecret,
+		Endpoint: oauth2.Endpoint{
+			TokenURL: p.RedeemURL.String(),
+		},
+	}
+	ctx := context.Background()
+	t := &oauth2.Token{
+		RefreshToken: s.RefreshToken,
+		Expiry:       time.Now().Add(-time.Hour),
+	}
+	token, err := c.TokenSource(ctx, t).Token()
+	if err != nil {
+		return fmt.Errorf("failed to get token: %v", err)
+	}
+	newSession, err := p.createSessionState(ctx, token)
+	if err != nil {
+		return fmt.Errorf("unable to update session: %v", err)
+	}
+	s.AccessToken = newSession.AccessToken
+	s.IDToken = newSession.IDToken
+	s.RefreshToken = newSession.RefreshToken
+	s.CreatedAt = newSession.CreatedAt
+	s.ExpiresOn = newSession.ExpiresOn
+	s.Email = newSession.Email
+	return
+}
+
+type gitlabUserInfo struct {
+	Username      string   `json:"nickname"`
+	Email         string   `json:"email"`
+	EmailVerified bool     `json:"email_verified"`
+	Groups        []string `json:"groups"`
+}
+
+func (p *GitLabProvider) getUserInfo(s *sessions.SessionState) (*gitlabUserInfo, error) {
+	// Retrieve user info JSON
+	// https://docs.gitlab.com/ee/integration/openid_connect_provider.html#shared-information
+
+	// Build user info url from login url of GitLab instance
+	userInfoURL := *p.LoginURL
+	userInfoURL.Path = "/oauth/userinfo"
+
+	req, err := http.NewRequest("GET", userInfoURL.String(), nil)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create user info request: %v", err)
+	}
+	req.Header.Set("Authorization", "Bearer "+s.AccessToken)
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("failed to perform user info request: %v", err)
+	}
+	var body []byte
+	body, err = ioutil.ReadAll(resp.Body)
+	resp.Body.Close()
+	if err != nil {
+		return nil, fmt.Errorf("failed to read user info response: %v", err)
+	}
+
+	if resp.StatusCode != 200 {
+		return nil, fmt.Errorf("got %d during user info request: %s", resp.StatusCode, body)
+	}
+
+	var userInfo gitlabUserInfo
+	err = json.Unmarshal(body, &userInfo)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse user info: %v", err)
+	}
+
+	return &userInfo, nil
+}
+
+func (p *GitLabProvider) verifyGroupMembership(userInfo *gitlabUserInfo) error {
+	if p.Group == "" {
+		return nil
+	}
+
+	// Collect user group memberships
+	membershipSet := make(map[string]bool)
+	for _, group := range userInfo.Groups {
+		membershipSet[group] = true
+	}
+
+	// Find a valid group that they are a member of
+	validGroups := strings.Split(p.Group, " ")
+	for _, validGroup := range validGroups {
+		if _, ok := membershipSet[validGroup]; ok {
+			return nil
+		}
+	}
+
+	return fmt.Errorf("user is not a member of '%s'", p.Group)
+}
+
+func (p *GitLabProvider) verifyEmailDomain(userInfo *gitlabUserInfo) error {
+	if len(p.EmailDomains) == 0 || p.EmailDomains[0] == "*" {
+		return nil
+	}
+
+	for _, domain := range p.EmailDomains {
+		if strings.HasSuffix(userInfo.Email, domain) {
+			return nil
+		}
+	}
+
+	return fmt.Errorf("user email is not one of the valid domains '%v'", p.EmailDomains)
+}
+
+func (p *GitLabProvider) 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")
+	}
+
+	// Parse and verify ID Token payload.
+	idToken, err := p.Verifier.Verify(ctx, rawIDToken)
+	if err != nil {
+		return nil, fmt.Errorf("could not verify id_token: %v", err)
+	}
+
+	return &sessions.SessionState{
+		AccessToken:  token.AccessToken,
+		IDToken:      rawIDToken,
+		RefreshToken: token.RefreshToken,
+		CreatedAt:    time.Now(),
+		ExpiresOn:    idToken.Expiry,
+	}, nil
+}
+
+// ValidateSessionState checks that the session's IDToken is still valid
+func (p *GitLabProvider) ValidateSessionState(s *sessions.SessionState) bool {
+	ctx := context.Background()
+	_, err := p.Verifier.Verify(ctx, s.IDToken)
+	if err != nil {
+		return false
+	}
+
+	return true
+}
+
 // GetEmailAddress returns the Account email address
 func (p *GitLabProvider) GetEmailAddress(s *sessions.SessionState) (string, error) {
+	// Retrieve user info
+	userInfo, err := p.getUserInfo(s)
+	if err != nil {
+		return "", fmt.Errorf("failed to retrieve user info: %v", err)
+	}

-	req, err := http.NewRequest("GET",
-		p.ValidateURL.String()+"?access_token="+s.AccessToken, nil)
-	if err != nil {
-		logger.Printf("failed building request %s", err)
-		return "", err
+	// Check if email is verified
+	if !p.AllowUnverifiedEmail && !userInfo.EmailVerified {
+		return "", fmt.Errorf("user email is not verified")
 	}
-	json, err := requests.Request(req)
+
+	// Check if email has valid domain
+	err = p.verifyEmailDomain(userInfo)
 	if err != nil {
-		logger.Printf("failed making request %s", err)
-		return "", err
+		return "", fmt.Errorf("email domain check failed: %v", err)
 	}
-	return json.Get("email").String()
+
+	// Check group membership
+	err = p.verifyGroupMembership(userInfo)
+	if err != nil {
+		return "", fmt.Errorf("group membership check failed: %v", err)
+	}
+
+	return userInfo.Email, nil
+}
+
+// GetUserName returns the Account user name
+func (p *GitLabProvider) GetUserName(s *sessions.SessionState) (string, error) {
+	userInfo, err := p.getUserInfo(s)
+	if err != nil {
+		return "", fmt.Errorf("failed to retrieve user info: %v", err)
+	}
+
+	return userInfo.Username, nil
 }
--- a/providers/gitlab_test.go
+++ b/providers/gitlab_test.go
@ -25,104 +25,142 @@ func testGitLabProvider(hostname string) *GitLabProvider {
 		updateURL(p.Data().ProfileURL, hostname)
 		updateURL(p.Data().ValidateURL, hostname)
 	}
+
 	return p
 }

-func testGitLabBackend(payload string) *httptest.Server {
-	path := "/api/v4/user"
-	query := "access_token=imaginary_access_token"
+func testGitLabBackend() *httptest.Server {
+	userInfo := `
+		{
+			"nickname": "FooBar",
+			"email": "foo@bar.com",
+			"email_verified": false,
+			"groups": ["foo", "bar"]
+		}
+	`
+	authHeader := "Bearer gitlab_access_token"

 	return httptest.NewServer(http.HandlerFunc(
 		func(w http.ResponseWriter, r *http.Request) {
-			if r.URL.Path != path || r.URL.RawQuery != query {
-				w.WriteHeader(404)
+			if r.URL.Path == "/oauth/userinfo" {
+				if r.Header["Authorization"][0] == authHeader {
+					w.WriteHeader(200)
+					w.Write([]byte(userInfo))
+				} else {
+					w.WriteHeader(401)
+				}
 			} else {
-				w.WriteHeader(200)
-				w.Write([]byte(payload))
+				w.WriteHeader(404)
 			}
 		}))
 }

-func TestGitLabProviderDefaults(t *testing.T) {
-	p := testGitLabProvider("")
-	assert.NotEqual(t, nil, p)
-	assert.Equal(t, "GitLab", p.Data().ProviderName)
-	assert.Equal(t, "https://gitlab.com/oauth/authorize",
-		p.Data().LoginURL.String())
-	assert.Equal(t, "https://gitlab.com/oauth/token",
-		p.Data().RedeemURL.String())
-	assert.Equal(t, "https://gitlab.com/api/v4/user",
-		p.Data().ValidateURL.String())
-	assert.Equal(t, "read_user", p.Data().Scope)
-}
-
-func TestGitLabProviderOverrides(t *testing.T) {
-	p := NewGitLabProvider(
-		&ProviderData{
-			LoginURL: &url.URL{
-				Scheme: "https",
-				Host:   "example.com",
-				Path:   "/oauth/auth"},
-			RedeemURL: &url.URL{
-				Scheme: "https",
-				Host:   "example.com",
-				Path:   "/oauth/token"},
-			ValidateURL: &url.URL{
-				Scheme: "https",
-				Host:   "example.com",
-				Path:   "/api/v4/user"},
-			Scope: "profile"})
-	assert.NotEqual(t, nil, p)
-	assert.Equal(t, "GitLab", p.Data().ProviderName)
-	assert.Equal(t, "https://example.com/oauth/auth",
-		p.Data().LoginURL.String())
-	assert.Equal(t, "https://example.com/oauth/token",
-		p.Data().RedeemURL.String())
-	assert.Equal(t, "https://example.com/api/v4/user",
-		p.Data().ValidateURL.String())
-	assert.Equal(t, "profile", p.Data().Scope)
-}
-
-func TestGitLabProviderGetEmailAddress(t *testing.T) {
-	b := testGitLabBackend("{\"email\": \"michael.bland@gsa.gov\"}")
+func TestGitLabProviderBadToken(t *testing.T) {
+	b := testGitLabBackend()
 	defer b.Close()

 	bURL, _ := url.Parse(b.URL)
 	p := testGitLabProvider(bURL.Host)

-	session := &sessions.SessionState{AccessToken: "imaginary_access_token"}
+	session := &sessions.SessionState{AccessToken: "unexpected_gitlab_access_token"}
+	_, err := p.GetEmailAddress(session)
+	assert.NotEqual(t, nil, err)
+}
+
+func TestGitLabProviderUnverifiedEmailDenied(t *testing.T) {
+	b := testGitLabBackend()
+	defer b.Close()
+
+	bURL, _ := url.Parse(b.URL)
+	p := testGitLabProvider(bURL.Host)
+
+	session := &sessions.SessionState{AccessToken: "gitlab_access_token"}
+	_, err := p.GetEmailAddress(session)
+	assert.NotEqual(t, nil, err)
+}
+
+func TestGitLabProviderUnverifiedEmailAllowed(t *testing.T) {
+	b := testGitLabBackend()
+	defer b.Close()
+
+	bURL, _ := url.Parse(b.URL)
+	p := testGitLabProvider(bURL.Host)
+	p.AllowUnverifiedEmail = true
+
+	session := &sessions.SessionState{AccessToken: "gitlab_access_token"}
 	email, err := p.GetEmailAddress(session)
 	assert.Equal(t, nil, err)
-	assert.Equal(t, "michael.bland@gsa.gov", email)
+	assert.Equal(t, "foo@bar.com", email)
 }

-// Note that trying to trigger the "failed building request" case is not
-// practical, since the only way it can fail is if the URL fails to parse.
-func TestGitLabProviderGetEmailAddressFailedRequest(t *testing.T) {
-	b := testGitLabBackend("unused payload")
+func TestGitLabProviderUsername(t *testing.T) {
+	b := testGitLabBackend()
 	defer b.Close()

 	bURL, _ := url.Parse(b.URL)
 	p := testGitLabProvider(bURL.Host)
+	p.AllowUnverifiedEmail = true

-	// 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 := &sessions.SessionState{AccessToken: "unexpected_access_token"}
-	email, err := p.GetEmailAddress(session)
-	assert.NotEqual(t, nil, err)
-	assert.Equal(t, "", email)
+	session := &sessions.SessionState{AccessToken: "gitlab_access_token"}
+	username, err := p.GetUserName(session)
+	assert.Equal(t, nil, err)
+	assert.Equal(t, "FooBar", username)
 }

-func TestGitLabProviderGetEmailAddressEmailNotPresentInPayload(t *testing.T) {
-	b := testGitLabBackend("{\"foo\": \"bar\"}")
+func TestGitLabProviderGroupMembershipValid(t *testing.T) {
+	b := testGitLabBackend()
 	defer b.Close()

 	bURL, _ := url.Parse(b.URL)
 	p := testGitLabProvider(bURL.Host)
+	p.AllowUnverifiedEmail = true
+	p.Group = "foo"

-	session := &sessions.SessionState{AccessToken: "imaginary_access_token"}
+	session := &sessions.SessionState{AccessToken: "gitlab_access_token"}
 	email, err := p.GetEmailAddress(session)
-	assert.NotEqual(t, nil, err)
-	assert.Equal(t, "", email)
+	assert.Equal(t, nil, err)
+	assert.Equal(t, "foo@bar.com", email)
+}
+
+func TestGitLabProviderGroupMembershipMissing(t *testing.T) {
+	b := testGitLabBackend()
+	defer b.Close()
+
+	bURL, _ := url.Parse(b.URL)
+	p := testGitLabProvider(bURL.Host)
+	p.AllowUnverifiedEmail = true
+	p.Group = "baz"
+
+	session := &sessions.SessionState{AccessToken: "gitlab_access_token"}
+	_, err := p.GetEmailAddress(session)
+	assert.NotEqual(t, nil, err)
+}
+
+func TestGitLabProviderEmailDomainValid(t *testing.T) {
+	b := testGitLabBackend()
+	defer b.Close()
+
+	bURL, _ := url.Parse(b.URL)
+	p := testGitLabProvider(bURL.Host)
+	p.AllowUnverifiedEmail = true
+	p.EmailDomains = []string{"bar.com"}
+
+	session := &sessions.SessionState{AccessToken: "gitlab_access_token"}
+	email, err := p.GetEmailAddress(session)
+	assert.Equal(t, nil, err)
+	assert.Equal(t, "foo@bar.com", email)
+}
+
+func TestGitLabProviderEmailDomainInvalid(t *testing.T) {
+	b := testGitLabBackend()
+	defer b.Close()
+
+	bURL, _ := url.Parse(b.URL)
+	p := testGitLabProvider(bURL.Host)
+	p.AllowUnverifiedEmail = true
+	p.EmailDomains = []string{"baz.com"}
+
+	session := &sessions.SessionState{AccessToken: "gitlab_access_token"}
+	_, err := p.GetEmailAddress(session)
+	assert.NotEqual(t, nil, err)
 }
--- a/providers/google.go
+++ b/providers/google.go
@ -189,73 +189,44 @@ func getAdminService(adminEmail string, credentialsReader io.Reader) *admin.Serv
 }

 func userInGroup(service *admin.Service, groups []string, email string) bool {
-	user, err := fetchUser(service, email)
-	if err != nil {
-		logger.Printf("Warning: unable to fetch user: %v", err)
-		user = nil
-	}
-
 	for _, group := range groups {
-		members, err := fetchGroupMembers(service, group)
+		// Use the HasMember API to checking for the user's presence in each group or nested subgroups
+		req := service.Members.HasMember(group, email)
+		r, err := req.Do()
 		if err != nil {
-			if err, ok := err.(*googleapi.Error); ok && err.Code == 404 {
-				logger.Printf("error fetching members for group %s: group does not exist", group)
-			} else {
-				logger.Printf("error fetching group members: %v", err)
-				return false
-			}
-		}
+			err, ok := err.(*googleapi.Error)
+			if ok && err.Code == 404 {
+				logger.Printf("error checking membership in group %s: group does not exist", group)
+			} else if ok && err.Code == 400 {
+				// It is possible for Members.HasMember to return false even if the email is a group member.
+				// One case that can cause this is if the user email is from a different domain than the group,
+				// e.g. "member@otherdomain.com" in the group "group@mydomain.com" will result in a 400 error
+				// from the HasMember API. In that case, attempt to query the member object directly from the group.
+				req := service.Members.Get(group, email)
+				r, err := req.Do()

-		for _, member := range members {
-			if member.Email == email {
-				return true
-			}
-			if user == nil {
-				continue
-			}
-			switch member.Type {
-			case "CUSTOMER":
-				if member.Id == user.CustomerId {
-					return true
-				}
-			case "USER":
-				if member.Id == user.Id {
+				if err != nil {
+					logger.Printf("error using get API to check member %s of google group %s: user not in the group", email, group)
+					continue
+				}
+
+				// If the non-domain user is found within the group, still verify that they are "ACTIVE".
+				// Do not count the user as belonging to a group if they have another status ("ARCHIVED", "SUSPENDED", or "UNKNOWN").
+				if r.Status == "ACTIVE" {
 					return true
 				}
+			} else {
+				logger.Printf("error checking group membership: %v", err)
 			}
+			continue
+		}
+		if r.IsMember {
+			return true
 		}
 	}
 	return false
 }

-func fetchUser(service *admin.Service, email string) (*admin.User, error) {
-	user, err := service.Users.Get(email).Do()
-	return user, err
-}
-
-func fetchGroupMembers(service *admin.Service, group string) ([]*admin.Member, error) {
-	members := []*admin.Member{}
-	pageToken := ""
-	for {
-		req := service.Members.List(group)
-		if pageToken != "" {
-			req.PageToken(pageToken)
-		}
-		r, err := req.Do()
-		if err != nil {
-			return nil, err
-		}
-		for _, member := range r.Members {
-			members = append(members, member)
-		}
-		if r.NextPageToken == "" {
-			break
-		}
-		pageToken = r.NextPageToken
-	}
-	return members, nil
-}
-
 // ValidateGroup validates that the provided email exists in the configured Google
 // group(s).
 func (p *GoogleProvider) ValidateGroup(email string) bool {
--- a/providers/google_test.go
+++ b/providers/google_test.go
@ -1,6 +1,7 @@
 package providers

 import (
+	"context"
 	"encoding/base64"
 	"encoding/json"
 	"fmt"
@ -12,6 +13,7 @@ import (
 	"github.com/stretchr/testify/assert"

 	admin "google.golang.org/api/admin/directory/v1"
+	option "google.golang.org/api/option"
 )

 func newRedeemServer(body []byte) (*url.URL, *httptest.Server) {
@ -185,34 +187,53 @@ func TestGoogleProviderGetEmailAddressEmailMissing(t *testing.T) {

 func TestGoogleProviderUserInGroup(t *testing.T) {
 	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		if r.URL.Path == "/users/member-by-email@example.com" {
-			fmt.Fprintln(w, "{}")
-		} else if r.URL.Path == "/users/non-member-by-email@example.com" {
-			fmt.Fprintln(w, "{}")
-		} else if r.URL.Path == "/users/member-by-id@example.com" {
-			fmt.Fprintln(w, "{\"id\": \"member-id\"}")
-		} else if r.URL.Path == "/users/non-member-by-id@example.com" {
-			fmt.Fprintln(w, "{\"id\": \"non-member-id\"}")
-		} else if r.URL.Path == "/groups/group@example.com/members" {
-			fmt.Fprintln(w, "{\"members\": [{\"email\": \"member-by-email@example.com\"}, {\"id\": \"member-id\", \"type\": \"USER\"}]}")
+		if r.URL.Path == "/groups/group@example.com/hasMember/member-in-domain@example.com" {
+			fmt.Fprintln(w, `{"isMember": true}`)
+		} else if r.URL.Path == "/groups/group@example.com/hasMember/non-member-in-domain@example.com" {
+			fmt.Fprintln(w, `{"isMember": false}`)
+		} else if r.URL.Path == "/groups/group@example.com/hasMember/member-out-of-domain@otherexample.com" {
+			http.Error(
+				w,
+				`{"error": {"errors": [{"domain": "global","reason": "invalid","message": "Invalid Input: memberKey"}],"code": 400,"message": "Invalid Input: memberKey"}}`,
+				http.StatusBadRequest,
+			)
+		} else if r.URL.Path == "/groups/group@example.com/hasMember/non-member-out-of-domain@otherexample.com" {
+			http.Error(
+				w,
+				`{"error": {"errors": [{"domain": "global","reason": "invalid","message": "Invalid Input: memberKey"}],"code": 400,"message": "Invalid Input: memberKey"}}`,
+				http.StatusBadRequest,
+			)
+		} else if r.URL.Path == "/groups/group@example.com/members/non-member-out-of-domain@otherexample.com" {
+			// note that the client currently doesn't care what this response text or code is - any error here results in failure to match the group
+			http.Error(
+				w,
+				`{"error": {"errors": [{"domain": "global","reason": "notFound","message": "Resource Not Found: memberKey"}],"code": 404,"message": "Resource Not Found: memberKey"}}`,
+				http.StatusNotFound,
+			)
+		} else if r.URL.Path == "/groups/group@example.com/members/member-out-of-domain@otherexample.com" {
+			fmt.Fprintln(w,
+				`{"kind": "admin#directory#member","etag":"12345","id":"1234567890","email": "member-out-of-domain@otherexample.com","role": "MEMBER","type": "USER","status": "ACTIVE","delivery_settings": "ALL_MAIL"}}`,
+			)
 		}
 	}))
 	defer ts.Close()

 	client := ts.Client()
-	service, err := admin.New(client)
+	ctx := context.Background()
+
+	service, err := admin.NewService(ctx, option.WithHTTPClient(client))
 	service.BasePath = ts.URL
 	assert.Equal(t, nil, err)

-	result := userInGroup(service, []string{"group@example.com"}, "member-by-email@example.com")
+	result := userInGroup(service, []string{"group@example.com"}, "member-in-domain@example.com")
 	assert.True(t, result)

-	result = userInGroup(service, []string{"group@example.com"}, "member-by-id@example.com")
+	result = userInGroup(service, []string{"group@example.com"}, "member-out-of-domain@otherexample.com")
 	assert.True(t, result)

-	result = userInGroup(service, []string{"group@example.com"}, "non-member-by-id@example.com")
+	result = userInGroup(service, []string{"group@example.com"}, "non-member-in-domain@example.com")
 	assert.False(t, result)

-	result = userInGroup(service, []string{"group@example.com"}, "non-member-by-email@example.com")
+	result = userInGroup(service, []string{"group@example.com"}, "non-member-out-of-domain@otherexample.com")
 	assert.False(t, result)
 }
--- a/providers/oidc.go
+++ b/providers/oidc.go
@ -3,10 +3,13 @@ package providers
 import (
 	"context"
 	"fmt"
+	"net/http"
 	"time"

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

@ -117,8 +120,31 @@ func (p *OIDCProvider) createSessionState(ctx context.Context, token *oauth2.Tok
 	}

 	if claims.Email == "" {
-		// TODO: Try getting email from /userinfo before falling back to Subject
-		claims.Email = claims.Subject
+		if p.ProfileURL.String() == "" {
+			return nil, fmt.Errorf("id_token did not contain an email")
+		}
+
+		// If the userinfo endpoint profileURL is defined, then there is a chance the userinfo
+		// contents at the profileURL contains the email.
+		// Make a query to the userinfo endpoint, and attempt to locate the email from there.
+
+		req, err := http.NewRequest("GET", p.ProfileURL.String(), nil)
+		if err != nil {
+			return nil, err
+		}
+		req.Header = getOIDCHeader(token.AccessToken)
+
+		respJSON, err := requests.Request(req)
+		if err != nil {
+			return nil, err
+		}
+
+		email, err := respJSON.Get("email").String()
+		if err != nil {
+			return nil, fmt.Errorf("Neither id_token nor userinfo endpoint contained an email")
+		}
+
+		claims.Email = email
 	}
 	if !p.AllowUnverifiedEmail && claims.Verified != nil && !*claims.Verified {
 		return nil, fmt.Errorf("email in id_token (%s) isn't verified", claims.Email)
@ -145,3 +171,10 @@ func (p *OIDCProvider) ValidateSessionState(s *sessions.SessionState) bool {

 	return true
 }
+
+func getOIDCHeader(accessToken string) http.Header {
+	header := make(http.Header)
+	header.Set("Accept", "application/json")
+	header.Set("Authorization", fmt.Sprintf("Bearer %s", accessToken))
+	return header
+}