add login.gov provider (#55)

* first stab at login.gov provider

* fixing bugs now that I think I understand things better

* fixing up dependencies

* remove some debug stuff

* Fixing all dependencies to point at my fork

* forgot to hit save on the github rehome here

* adding options for setting keys and so on, use JWT workflow instead of PKCE

* forgot comma

* was too aggressive with search/replace

* need JWTKey to be byte array

* removed custom refresh stuff

* do our own custom jwt claim and store it in the normal session store

* golang json types are strange

* I have much to learn about golang

* fix time and signing key

* add http lib

* fixed claims up since we don't need custom claims

* add libs

* forgot ioutil

* forgot ioutil

* moved back to pusher location

* changed proxy github location back so that it builds externally, fixed up []byte stuff, removed client_secret if we are using login.gov

* update dependencies

* do JWTs properly

* finished oidc flow, fixed up tests to work better

* updated comments, added test that we set expiresOn properly

* got confused with header and post vs get

* clean up debug and test dir

* add login.gov to README, remove references to my repo

* forgot to remove un-needed code

* can use sample_key* instead of generating your own

* updated changelog

* apparently golint wants comments like this

* linter wants non-standard libs in a separate grouping

* Update options.go

Co-Authored-By: timothy-spencer <timothy.spencer@gsa.gov>

* Update options.go

Co-Authored-By: timothy-spencer <timothy.spencer@gsa.gov>

* remove sample_key, improve comments related to client-secret, fix changelog related to PR feedback

* github doesn't seem to do gofmt when merging.  :-)

* update CODEOWNERS

* check the nonce

* validate the JWT fully

* forgot to add pubjwk-url to README

* unexport the struct

* fix up the err masking that travis found

* update nonce comment by request of @JoelSpeed

* argh.  Thought I'd formatted the merge properly, but apparently not.

* fixed test to not fail if the query time was greater than zero

.github/CODEOWNERS

@@ -1,3 +1,12 @@
 # Default owner should be a Pusher cloud-team member unless overridden by later
 # rules in this file
 * @pusher/cloud-team
+
+# login.gov provider
+# Note:  If @timothy-spencer terms out of his appointment, your best bet
+# for finding somebody who can test the oauth2_proxy would be to ask somebody
+# in the login.gov team (https://login.gov/developers/), the cloud.gov team
+# (https://cloud.gov/docs/help/), or the 18F org (https://18f.gsa.gov/contact/
+# or the public devops channel at https://chat.18f.gov/).
+providers/logingov.go @timothy-spencer
+providers/logingov_test.go @timothy-spencer

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## Changes since v3.1.0
 
+- [#55](https://github.com/pusher/oauth2_proxy/pull/55) Added login.gov provider (@timothy-spencer)
+- [#55](https://github.com/pusher/oauth2_proxy/pull/55) Added environment variables for all config options (@timothy-spencer)
 - [#70](https://github.com/pusher/oauth2_proxy/pull/70) Fix handling of splitted cookies (@einfachchr)
 - [#92](https://github.com/pusher/oauth2_proxy/pull/92) Merge websocket proxy feature from openshift/oauth-proxy (@butzist)
 - [#57](https://github.com/pusher/oauth2_proxy/pull/57) Fall back to using OIDC Subject instead of Email (@aigarius)

Gopkg.lock

@@ -41,6 +41,14 @@
   revision = "346938d642f2ec3594ed81d874461961cd0faa76"
   version = "v1.1.0"
 
+[[projects]]
+  digest = "1:6098222470fe0172157ce9bbef5d2200df4edde17ee649c5d6e48330e4afa4c6"
+  name = "github.com/dgrijalva/jwt-go"
+  packages = ["."]
+  pruneopts = ""
+  revision = "06ea1031745cb8b3dab3f6a236daf2b0aa468b7e"
+  version = "v3.2.0"
+
 [[projects]]
   branch = "master"
   digest = "1:3b760d3b93f994df8eb1d9ebfad17d3e9e37edcb7f7efaa15b427c0d7a64f4e4"
@@ -201,6 +209,7 @@
     "github.com/BurntSushi/toml",
     "github.com/bitly/go-simplejson",
     "github.com/coreos/go-oidc",
+    "github.com/dgrijalva/jwt-go",
     "github.com/mbland/hmacauth",
     "github.com/mreiferson/go-options",
     "github.com/stretchr/testify/assert",

README.md

@@ -48,6 +48,7 @@ Valid providers are :
 - [GitHub](#github-auth-provider)
 - [GitLab](#gitlab-auth-provider)
 - [LinkedIn](#linkedin-auth-provider)
+- [login.gov](#login.gov-provider)
 
 The provider can be selected using the `provider` configuration value.
 
@@ -166,6 +167,54 @@ OpenID Connect is a spec for OAUTH 2.0 + identity that is implemented by many ma
     -cookie-secure=false
     -email-domain example.com
 
+### login.gov Provider
+
+login.gov is an OIDC provider for the US Government.
+If you are a US Government agency, you can contact the login.gov team through the contact information
+that you can find on https://login.gov/developers/ and work with them to understand how to get login.gov
+accounts for integration/test and production access.  
+
+A developer guide is available here: https://developers.login.gov/, though this proxy handles everything
+but the data you need to create to register your application in the login.gov dashboard.
+
+As a demo, we will assume that you are running your application that you want to secure locally on 
+http://localhost:3000/, that you will be starting your proxy up on http://localhost:4180/, and that
+you have an agency integration account for testing.
+
+First, register your application in the dashboard.  The important bits are:
+  * Identity protocol:  make this `Openid connect`
+  * Issuer:  do what they say for OpenID Connect.  We will refer to this string as `${LOGINGOV_ISSUER}`.
+  * Public key:  This is a self-signed certificate in .pem format generated from a 2048 bit RSA private key.
+    A quick way to do this is `openssl req -x509 -newkey rsa:2048 -keyout key.pem -out cert.pem -days 3650 -nodes -subj '/C=US/ST=Washington/L=DC/O=GSA/OU=18F/CN=localhost'`,
+    The contents of the `key.pem` shall be referred to as `${OAUTH2_PROXY_JWT_KEY}`.
+  * Return to App URL:  Make this be `http://localhost:4180/`
+  * Redirect URIs:  Make this be `http://localhost:4180/oauth2/callback`.
+  * Attribute Bundle:  Make sure that email is selected.
+
+Now start the proxy up with the following options:
+```
+./oauth2_proxy -provider login.gov \
+  -client-id=${LOGINGOV_ISSUER} \
+  -redirect-url=http://localhost:4180/oauth2/callback \
+  -oidc-issuer-url=https://idp.int.identitysandbox.gov/ \
+  -cookie-secure=false \
+  -email-domain=gsa.gov \
+  -upstream=http://localhost:3000/ \
+  -cookie-secret=somerandomstring12341234567890AB \
+  -cookie-domain=localhost \
+  -skip-provider-button=true \
+  -pubjwk-url=https://idp.int.identitysandbox.gov/api/openid_connect/certs \
+  -profile-url=https://idp.int.identitysandbox.gov/api/openid_connect/userinfo \
+  -jwt-key="${OAUTH2_PROXY_JWT_KEY}"
+```
+You can also set all these options with environment variables, for use in cloud/docker environments.
+
+Once it is running, you should be able to go to `http://localhost:4180/` in your browser,
+get authenticated by the login.gov integration server, and then get proxied on to your
+application running on `http://localhost:3000/`.  In a real deployment, you would secure
+your application with a firewall or something so that it was only accessible from the
+proxy, and you would use real hostnames everywhere.
+
 #### Skip OIDC discovery
 
 Some providers do not support OIDC discovery via their issuer URL, so oauth2_proxy cannot simply grab the authorization, token and jwks URI endpoints from the provider's metadata.

logging_handler_test.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"net/http"
 	"net/http/httptest"
+	"strings"
 	"testing"
 	"time"
 )
@@ -16,7 +17,7 @@ func TestLoggingHandler_ServeHTTP(t *testing.T) {
 		Format,
 		ExpectedLogMessage string
 	}{
-		{defaultRequestLoggingFormat, fmt.Sprintf("127.0.0.1 - - [%s] test-server GET - \"/foo/bar\" HTTP/1.1 \"\" 200 4 0.000\n", ts.Format("02/Jan/2006:15:04:05 -0700"))},
+		{defaultRequestLoggingFormat, fmt.Sprintf("127.0.0.1 - - [%s] test-server GET - \"/foo/bar\" HTTP/1.1 \"\" 200 4 0", ts.Format("02/Jan/2006:15:04:05 -0700"))},
 		{"{{.RequestMethod}}", "GET\n"},
 	}
 
@@ -35,8 +36,8 @@ func TestLoggingHandler_ServeHTTP(t *testing.T) {
 		h.ServeHTTP(httptest.NewRecorder(), r)
 
 		actual := buf.String()
-		if actual != test.ExpectedLogMessage {
+		if !strings.Contains(actual, test.ExpectedLogMessage) {
-			t.Errorf("Log message was\n%s\ninstead of expected \n%s", actual, test.ExpectedLogMessage)
+			t.Errorf("Log message was\n%s\ninstead of matching \n%s", actual, test.ExpectedLogMessage)
 		}
 	}
 }

main.go

@@ -4,6 +4,7 @@ import (
 	"flag"
 	"fmt"
 	"log"
+	"math/rand"
 	"os"
 	"runtime"
 	"strings"
@@ -88,6 +89,9 @@ func main() {
 	flagSet.String("approval-prompt", "force", "OAuth approval_prompt")
 
 	flagSet.String("signature-key", "", "GAP-Signature request signature key (algorithm:secretkey)")
+	flagSet.String("acr-values", "http://idmanagement.gov/ns/assurance/loa/1", "acr values string:  optional, used by login.gov")
+	flagSet.String("jwt-key", "", "private key used to sign JWT: required by login.gov")
+	flagSet.String("pubjwk-url", "", "JWK pubkey access endpoint: required by login.gov")
 
 	flagSet.Parse(os.Args[1:])
 
@@ -133,6 +137,8 @@ func main() {
 		}
 	}
 
+	rand.Seed(time.Now().UnixNano())
+
 	s := &Server{
 		Handler: LoggingHandler(os.Stdout, oauthproxy, opts.RequestLogging, opts.RequestLoggingFormat),
 		Opts:    opts,

options.go

@@ -14,6 +14,7 @@ import (
 	"time"
 
 	oidc "github.com/coreos/go-oidc"
+	"github.com/dgrijalva/jwt-go"
 	"github.com/mbland/hmacauth"
 	"github.com/pusher/oauth2_proxy/providers"
 )
@@ -21,71 +22,74 @@ import (
 // Options holds Configuration Options that can be set by Command Line Flag,
 // or Config File
 type Options struct {
-	ProxyPrefix     string `flag:"proxy-prefix" cfg:"proxy-prefix"`
+	ProxyPrefix     string `flag:"proxy-prefix" cfg:"proxy-prefix" env:"OAUTH2_PROXY_PROXY_PREFIX"`
-	ProxyWebSockets bool   `flag:"proxy-websockets" cfg:"proxy_websockets"`
+	ProxyWebSockets bool   `flag:"proxy-websockets" cfg:"proxy_websockets" env:"OAUTH2_PROXY_PROXY_WEBSOCKETS"`
-	HTTPAddress     string `flag:"http-address" cfg:"http_address"`
+	HTTPAddress     string `flag:"http-address" cfg:"http_address" env:"OAUTH2_PROXY_HTTP_ADDRESS"`
-	HTTPSAddress    string `flag:"https-address" cfg:"https_address"`
+	HTTPSAddress    string `flag:"https-address" cfg:"https_address" env:"OAUTH2_PROXY_HTTPS_ADDRESS"`
-	RedirectURL     string `flag:"redirect-url" cfg:"redirect_url"`
+	RedirectURL     string `flag:"redirect-url" cfg:"redirect_url" env:"OAUTH2_PROXY_REDIRECT_URL"`
 	ClientID        string `flag:"client-id" cfg:"client_id" env:"OAUTH2_PROXY_CLIENT_ID"`
 	ClientSecret    string `flag:"client-secret" cfg:"client_secret" env:"OAUTH2_PROXY_CLIENT_SECRET"`
-	TLSCertFile     string `flag:"tls-cert" cfg:"tls_cert_file"`
+	TLSCertFile     string `flag:"tls-cert" cfg:"tls_cert_file" env:"OAUTH2_PROXY_TLS_CERT_FILE"`
-	TLSKeyFile      string `flag:"tls-key" cfg:"tls_key_file"`
+	TLSKeyFile      string `flag:"tls-key" cfg:"tls_key_file" env:"OAUTH2_PROXY_TLS_KEY_FILE"`
 
-	AuthenticatedEmailsFile  string   `flag:"authenticated-emails-file" cfg:"authenticated_emails_file"`
+	AuthenticatedEmailsFile  string   `flag:"authenticated-emails-file" cfg:"authenticated_emails_file" env:"OAUTH2_PROXY_AUTHENTICATED_EMAILS_FILE"`
-	AzureTenant              string   `flag:"azure-tenant" cfg:"azure_tenant"`
+	AzureTenant              string   `flag:"azure-tenant" cfg:"azure_tenant" env:"OAUTH2_PROXY_AZURE_TENANT"`
-	EmailDomains             []string `flag:"email-domain" cfg:"email_domains"`
+	EmailDomains             []string `flag:"email-domain" cfg:"email_domains" env:"OAUTH2_PROXY_EMAIL_DOMAINS"`
 	WhitelistDomains         []string `flag:"whitelist-domain" cfg:"whitelist_domains" env:"OAUTH2_PROXY_WHITELIST_DOMAINS"`
-	GitHubOrg                string   `flag:"github-org" cfg:"github_org"`
+	GitHubOrg                string   `flag:"github-org" cfg:"github_org" env:"OAUTH2_PROXY_GITHUB_ORG"`
-	GitHubTeam               string   `flag:"github-team" cfg:"github_team"`
+	GitHubTeam               string   `flag:"github-team" cfg:"github_team" env:"OAUTH2_PROXY_GITHUB_TEAM"`
-	GoogleGroups             []string `flag:"google-group" cfg:"google_group"`
+	GoogleGroups             []string `flag:"google-group" cfg:"google_group" env:"OAUTH2_PROXY_GOOGLE_GROUPS"`
-	GoogleAdminEmail         string   `flag:"google-admin-email" cfg:"google_admin_email"`
+	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"`
+	GoogleServiceAccountJSON string   `flag:"google-service-account-json" cfg:"google_service_account_json" env:"OAUTH2_PROXY_GOOGLE_SERVICE_ACCOUNT_JSON"`
-	HtpasswdFile             string   `flag:"htpasswd-file" cfg:"htpasswd_file"`
+	HtpasswdFile             string   `flag:"htpasswd-file" cfg:"htpasswd_file" env:"OAUTH2_PROXY_HTPASSWD_FILE"`
-	DisplayHtpasswdForm      bool     `flag:"display-htpasswd-form" cfg:"display_htpasswd_form"`
+	DisplayHtpasswdForm      bool     `flag:"display-htpasswd-form" cfg:"display_htpasswd_form" env:"OAUTH2_PROXY_DISPLAY_HTPASSWD_FORM"`
-	CustomTemplatesDir       string   `flag:"custom-templates-dir" cfg:"custom_templates_dir"`
+	CustomTemplatesDir       string   `flag:"custom-templates-dir" cfg:"custom_templates_dir" env:"OAUTH2_PROXY_CUSTOM_TEMPLATES_DIR"`
-	Footer                   string   `flag:"footer" cfg:"footer"`
+	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"`
 	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"`
+	CookieSecure   bool          `flag:"cookie-secure" cfg:"cookie_secure" env:"OAUTH2_PROXY_COOKIE_SECURE"`
-	CookieHTTPOnly bool          `flag:"cookie-httponly" cfg:"cookie_httponly"`
+	CookieHTTPOnly bool          `flag:"cookie-httponly" cfg:"cookie_httponly" env:"OAUTH2_PROXY_COOKIE_HTTPONLY"`
 
-	Upstreams             []string      `flag:"upstream" cfg:"upstreams"`
+	Upstreams             []string      `flag:"upstream" cfg:"upstreams" env:"OAUTH2_PROXY_UPSTREAMS"`
-	SkipAuthRegex         []string      `flag:"skip-auth-regex" cfg:"skip_auth_regex"`
+	SkipAuthRegex         []string      `flag:"skip-auth-regex" cfg:"skip_auth_regex" env:"OAUTH2_PROXY_SKIP_AUTH_REGEX"`
-	PassBasicAuth         bool          `flag:"pass-basic-auth" cfg:"pass_basic_auth"`
+	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"`
+	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"`
+	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"`
+	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"`
+	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"`
+	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"`
+	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"`
+	SetXAuthRequest       bool          `flag:"set-xauthrequest" cfg:"set_xauthrequest" env:"OAUTH2_PROXY_SET_XAUTHREQUEST"`
-	SetAuthorization      bool          `flag:"set-authorization-header" cfg:"set_authorization_header"`
+	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"`
+	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"`
+	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"`
+	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.
-	Provider          string `flag:"provider" cfg:"provider"`
+	Provider          string `flag:"provider" cfg:"provider" env:"OAUTH2_PROXY_PROVIDER"`
-	OIDCIssuerURL     string `flag:"oidc-issuer-url" cfg:"oidc_issuer_url"`
+	OIDCIssuerURL     string `flag:"oidc-issuer-url" cfg:"oidc_issuer_url" env:"OAUTH2_PROXY_OIDC_ISSUER_URL"`
-	SkipOIDCDiscovery bool   `flag:"skip-oidc-discovery" cfg:"skip_oidc_discovery"`
+	SkipOIDCDiscovery bool   `flag:"skip-oidc-discovery" cfg:"skip_oidc_discovery" env:"OAUTH2_SKIP_OIDC_DISCOVERY"`
-	OIDCJwksURL       string `flag:"oidc-jwks-url" cfg:"oidc_jwks_url"`
+	OIDCJwksURL       string `flag:"oidc-jwks-url" cfg:"oidc_jwks_url" env:"OAUTH2_OIDC_JWKS_URL"`
-	LoginURL          string `flag:"login-url" cfg:"login_url"`
+	LoginURL          string `flag:"login-url" cfg:"login_url" env:"OAUTH2_PROXY_LOGIN_URL"`
-	RedeemURL         string `flag:"redeem-url" cfg:"redeem_url"`
+	RedeemURL         string `flag:"redeem-url" cfg:"redeem_url" env:"OAUTH2_PROXY_REDEEM_URL"`
-	ProfileURL        string `flag:"profile-url" cfg:"profile_url"`
+	ProfileURL        string `flag:"profile-url" cfg:"profile_url" env:"OAUTH2_PROXY_PROFILE_URL"`
-	ProtectedResource string `flag:"resource" cfg:"resource"`
+	ProtectedResource string `flag:"resource" cfg:"resource" env:"OAUTH2_PROXY_RESOURCE"`
-	ValidateURL       string `flag:"validate-url" cfg:"validate_url"`
+	ValidateURL       string `flag:"validate-url" cfg:"validate_url" env:"OAUTH2_PROXY_VALIDATE_URL"`
-	Scope             string `flag:"scope" cfg:"scope"`
+	Scope             string `flag:"scope" cfg:"scope" env:"OAUTH2_PROXY_SCOPE"`
-	ApprovalPrompt    string `flag:"approval-prompt" cfg:"approval_prompt"`
+	ApprovalPrompt    string `flag:"approval-prompt" cfg:"approval_prompt" env:"OAUTH2_PROXY_APPROVAL_PROMPT"`
 
-	RequestLogging       bool   `flag:"request-logging" cfg:"request_logging"`
+	RequestLogging       bool   `flag:"request-logging" cfg:"request_logging" env:"OAUTH2_PROXY_REQUEST_LOGGING"`
-	RequestLoggingFormat string `flag:"request-logging-format" cfg:"request_logging_format"`
+	RequestLoggingFormat string `flag:"request-logging-format" cfg:"request_logging_format" env:"OAUTH2_PROXY_REQUEST_LOGGING_FORMAT"`
 
 	SignatureKey string `flag:"signature-key" cfg:"signature_key" env:"OAUTH2_PROXY_SIGNATURE_KEY"`
+	AcrValues    string `flag:"acr-values" cfg:"acr_values" env:"OAUTH2_PROXY_ACR_VALUES"`
+	JWTKey       string `flag:"jwt-key" cfg:"jwt_key" env:"OAUTH2_PROXY_JWT_KEY"`
+	PubJWKURL    string `flag:"pubjwk-url" cfg:"pubjwk_url" env:"OAUTH2_PROXY_PUBJWK_URL"`
 
 	// internal values that are set after config validation
 	redirectURL   *url.URL
@@ -157,7 +161,8 @@ func (o *Options) Validate() error {
 	if o.ClientID == "" {
 		msgs = append(msgs, "missing setting: client-id")
 	}
-	if o.ClientSecret == "" {
+	// login.gov uses a signed JWT to authenticate, not a client-secret
+	if o.ClientSecret == "" && o.Provider != "login.gov" {
 		msgs = append(msgs, "missing setting: client-secret")
 	}
 	if o.AuthenticatedEmailsFile == "" && len(o.EmailDomains) == 0 && o.HtpasswdFile == "" {
@@ -318,6 +323,19 @@ func parseProviderInfo(o *Options, msgs []string) []string {
 		} else {
 			p.Verifier = o.oidcVerifier
 		}
+	case *providers.LoginGovProvider:
+		p.AcrValues = o.AcrValues
+		p.PubJWKURL, msgs = parseURL(o.PubJWKURL, "pubjwk", msgs)
+		if o.JWTKey == "" {
+			msgs = append(msgs, "login.gov provider requires a private key for signing JWTs")
+		} else {
+			signKey, err := jwt.ParseRSAPrivateKeyFromPEM([]byte(o.JWTKey))
+			if err != nil {
+				msgs = append(msgs, "could not parse RSA Private Key PEM")
+			} else {
+				p.JWTKey = signKey
+			}
+		}
 	}
 	return msgs
 }

providers/logingov.go

@@ -0,0 +1,275 @@
+package providers
+
+import (
+	"bytes"
+	"crypto/rsa"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"math/rand"
+	"net/http"
+	"net/url"
+	"time"
+
+	"github.com/dgrijalva/jwt-go"
+	"gopkg.in/square/go-jose.v2"
+)
+
+// LoginGovProvider represents an OIDC based Identity Provider
+type LoginGovProvider struct {
+	*ProviderData
+
+	// TODO (@timothy-spencer): Ideally, the nonce would be in the session state, but the session state
+	// is created only upon code redemption, not during the auth, when this must be supplied.
+	Nonce     string
+	AcrValues string
+	JWTKey    *rsa.PrivateKey
+	PubJWKURL *url.URL
+}
+
+// For generating a nonce
+var letters = []rune("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
+
+func randSeq(n int) string {
+	b := make([]rune, n)
+	for i := range b {
+		b[i] = letters[rand.Intn(len(letters))]
+	}
+	return string(b)
+}
+
+// NewLoginGovProvider initiates a new LoginGovProvider
+func NewLoginGovProvider(p *ProviderData) *LoginGovProvider {
+	p.ProviderName = "login.gov"
+
+	if p.LoginURL == nil || p.LoginURL.String() == "" {
+		p.LoginURL = &url.URL{
+			Scheme: "https",
+			Host:   "secure.login.gov",
+			Path:   "/openid_connect/authorize",
+		}
+	}
+	if p.RedeemURL == nil || p.RedeemURL.String() == "" {
+		p.RedeemURL = &url.URL{
+			Scheme: "https",
+			Host:   "secure.login.gov",
+			Path:   "/api/openid_connect/token",
+		}
+	}
+	if p.ProfileURL == nil || p.ProfileURL.String() == "" {
+		p.ProfileURL = &url.URL{
+			Scheme: "https",
+			Host:   "secure.login.gov",
+			Path:   "/api/openid_connect/userinfo",
+		}
+	}
+	if p.Scope == "" {
+		p.Scope = "email openid"
+	}
+
+	return &LoginGovProvider{
+		ProviderData: p,
+		Nonce:        randSeq(32),
+	}
+}
+
+type loginGovCustomClaims struct {
+	Acr           string `json:"acr"`
+	Nonce         string `json:"nonce"`
+	Email         string `json:"email"`
+	EmailVerified bool   `json:"email_verified"`
+	GivenName     string `json:"given_name"`
+	FamilyName    string `json:"family_name"`
+	Birthdate     string `json:"birthdate"`
+	AtHash        string `json:"at_hash"`
+	CHash         string `json:"c_hash"`
+	jwt.StandardClaims
+}
+
+// checkNonce checks the nonce in the id_token
+func checkNonce(idToken string, p *LoginGovProvider) (err error) {
+	token, err := jwt.ParseWithClaims(idToken, &loginGovCustomClaims{}, func(token *jwt.Token) (interface{}, error) {
+		resp, myerr := http.Get(p.PubJWKURL.String())
+		if myerr != nil {
+			return nil, myerr
+		}
+		if resp.StatusCode != 200 {
+			myerr = fmt.Errorf("got %d from %q", resp.StatusCode, p.PubJWKURL.String())
+			return nil, myerr
+		}
+		body, myerr := ioutil.ReadAll(resp.Body)
+		resp.Body.Close()
+		if myerr != nil {
+			return nil, myerr
+		}
+
+		var pubkeys jose.JSONWebKeySet
+		myerr = json.Unmarshal(body, &pubkeys)
+		if myerr != nil {
+			return nil, myerr
+		}
+		pubkey := pubkeys.Keys[0]
+
+		return pubkey.Key, nil
+	})
+	if err != nil {
+		return
+	}
+
+	claims := token.Claims.(*loginGovCustomClaims)
+	if claims.Nonce != p.Nonce {
+		err = fmt.Errorf("nonce validation failed")
+		return
+	}
+	return
+}
+
+func emailFromUserInfo(accessToken string, userInfoEndpoint string) (email string, err error) {
+	// query the user info endpoint for user attributes
+	var req *http.Request
+	req, err = http.NewRequest("GET", userInfoEndpoint, nil)
+	if err != nil {
+		return
+	}
+	req.Header.Set("Authorization", "Bearer "+accessToken)
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return
+	}
+	var body []byte
+	body, err = ioutil.ReadAll(resp.Body)
+	resp.Body.Close()
+	if err != nil {
+		return
+	}
+
+	if resp.StatusCode != 200 {
+		err = fmt.Errorf("got %d from %q %s", resp.StatusCode, userInfoEndpoint, body)
+		return
+	}
+
+	// parse the user attributes from the data we got and make sure that
+	// the email address has been validated.
+	var emailData struct {
+		Email         string `json:"email"`
+		EmailVerified bool   `json:"email_verified"`
+	}
+	err = json.Unmarshal(body, &emailData)
+	if err != nil {
+		return
+	}
+	if emailData.Email == "" {
+		err = fmt.Errorf("missing email")
+		return
+	}
+	email = emailData.Email
+	if !emailData.EmailVerified {
+		err = fmt.Errorf("email %s not listed as verified", email)
+		return
+	}
+	return
+}
+
+// Redeem exchanges the OAuth2 authentication token for an ID token
+func (p *LoginGovProvider) Redeem(redirectURL, code string) (s *SessionState, err error) {
+	if code == "" {
+		err = errors.New("missing code")
+		return
+	}
+
+	claims := &jwt.StandardClaims{
+		Issuer:    p.ClientID,
+		Subject:   p.ClientID,
+		Audience:  p.RedeemURL.String(),
+		ExpiresAt: int64(time.Now().Add(time.Duration(5 * time.Minute)).Unix()),
+		Id:        randSeq(32),
+	}
+	token := jwt.NewWithClaims(jwt.GetSigningMethod("RS256"), claims)
+	ss, err := token.SignedString(p.JWTKey)
+	if err != nil {
+		return
+	}
+
+	params := url.Values{}
+	params.Add("client_assertion", ss)
+	params.Add("client_assertion_type", "urn:ietf:params:oauth:client-assertion-type:jwt-bearer")
+	params.Add("code", code)
+	params.Add("grant_type", "authorization_code")
+
+	var req *http.Request
+	req, err = http.NewRequest("POST", p.RedeemURL.String(), bytes.NewBufferString(params.Encode()))
+	if err != nil {
+		return
+	}
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+
+	var resp *http.Response
+	resp, err = http.DefaultClient.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	var body []byte
+	body, err = ioutil.ReadAll(resp.Body)
+	resp.Body.Close()
+	if err != nil {
+		return
+	}
+
+	if resp.StatusCode != 200 {
+		err = fmt.Errorf("got %d from %q %s", resp.StatusCode, p.RedeemURL.String(), body)
+		return
+	}
+
+	// Get the token from the body that we got from the token endpoint.
+	var jsonResponse struct {
+		AccessToken string `json:"access_token"`
+		IDToken     string `json:"id_token"`
+		TokenType   string `json:"token_type"`
+		ExpiresIn   int64  `json:"expires_in"`
+	}
+	err = json.Unmarshal(body, &jsonResponse)
+	if err != nil {
+		return
+	}
+
+	// check nonce here
+	err = checkNonce(jsonResponse.IDToken, p)
+	if err != nil {
+		return
+	}
+
+	// Get the email address
+	var email string
+	email, err = emailFromUserInfo(jsonResponse.AccessToken, p.ProfileURL.String())
+	if err != nil {
+		return
+	}
+
+	// Store the data that we found in the session state
+	s = &SessionState{
+		AccessToken: jsonResponse.AccessToken,
+		IDToken:     jsonResponse.IDToken,
+		ExpiresOn:   time.Now().Add(time.Duration(jsonResponse.ExpiresIn) * time.Second).Truncate(time.Second),
+		Email:       email,
+	}
+	return
+}
+
+// GetLoginURL overrides GetLoginURL to add login.gov parameters
+func (p *LoginGovProvider) GetLoginURL(redirectURI, state string) string {
+	var a url.URL
+	a = *p.LoginURL
+	params, _ := url.ParseQuery(a.RawQuery)
+	params.Set("redirect_uri", redirectURI)
+	params.Set("approval_prompt", p.ApprovalPrompt)
+	params.Add("scope", p.Scope)
+	params.Set("client_id", p.ClientID)
+	params.Set("response_type", "code")
+	params.Add("state", state)
+	params.Add("acr_values", p.AcrValues)
+	params.Add("nonce", p.Nonce)
+	a.RawQuery = params.Encode()
+	return a.String()
+}

providers/logingov_test.go

@@ -0,0 +1,290 @@
+package providers
+
+import (
+	"crypto"
+	"crypto/rand"
+	"crypto/rsa"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"testing"
+	"time"
+
+	"github.com/dgrijalva/jwt-go"
+	"github.com/stretchr/testify/assert"
+	"gopkg.in/square/go-jose.v2"
+)
+
+type MyKeyData struct {
+	PubKey  crypto.PublicKey
+	PrivKey *rsa.PrivateKey
+	PubJWK  jose.JSONWebKey
+}
+
+func newLoginGovServer(body []byte) (*url.URL, *httptest.Server) {
+	s := httptest.NewServer(http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
+		rw.Write(body)
+	}))
+	u, _ := url.Parse(s.URL)
+	return u, s
+}
+
+func newLoginGovProvider() (l *LoginGovProvider, serverKey *MyKeyData, err error) {
+	key, err := rsa.GenerateKey(rand.Reader, 2048)
+	if err != nil {
+		return
+	}
+	serverKey = &MyKeyData{
+		PubKey:  key.Public(),
+		PrivKey: key,
+		PubJWK: jose.JSONWebKey{
+			Key:       key.Public(),
+			KeyID:     "testkey",
+			Algorithm: string(jose.RS256),
+			Use:       "sig",
+		},
+	}
+
+	privateKey, err := rsa.GenerateKey(rand.Reader, 2048)
+	if err != nil {
+		return
+	}
+
+	l = NewLoginGovProvider(
+		&ProviderData{
+			ProviderName: "",
+			LoginURL:     &url.URL{},
+			RedeemURL:    &url.URL{},
+			ProfileURL:   &url.URL{},
+			ValidateURL:  &url.URL{},
+			Scope:        ""})
+	l.JWTKey = privateKey
+	l.Nonce = "fakenonce"
+	return
+}
+
+func TestLoginGovProviderDefaults(t *testing.T) {
+	p, _, err := newLoginGovProvider()
+	assert.NotEqual(t, nil, p)
+	assert.NoError(t, err)
+	assert.Equal(t, "login.gov", p.Data().ProviderName)
+	assert.Equal(t, "https://secure.login.gov/openid_connect/authorize",
+		p.Data().LoginURL.String())
+	assert.Equal(t, "https://secure.login.gov/api/openid_connect/token",
+		p.Data().RedeemURL.String())
+	assert.Equal(t, "https://secure.login.gov/api/openid_connect/userinfo",
+		p.Data().ProfileURL.String())
+	assert.Equal(t, "email openid", p.Data().Scope)
+}
+
+func TestLoginGovProviderOverrides(t *testing.T) {
+	p := NewLoginGovProvider(
+		&ProviderData{
+			LoginURL: &url.URL{
+				Scheme: "https",
+				Host:   "example.com",
+				Path:   "/oauth/auth"},
+			RedeemURL: &url.URL{
+				Scheme: "https",
+				Host:   "example.com",
+				Path:   "/oauth/token"},
+			ProfileURL: &url.URL{
+				Scheme: "https",
+				Host:   "example.com",
+				Path:   "/oauth/profile"},
+			Scope: "profile"})
+	assert.NotEqual(t, nil, p)
+	assert.Equal(t, "login.gov", 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/oauth/profile",
+		p.Data().ProfileURL.String())
+	assert.Equal(t, "profile", p.Data().Scope)
+}
+
+func TestLoginGovProviderSessionData(t *testing.T) {
+	p, serverkey, err := newLoginGovProvider()
+	assert.NotEqual(t, nil, p)
+	assert.NoError(t, err)
+
+	// Set up the redeem endpoint here
+	type loginGovRedeemResponse struct {
+		AccessToken string `json:"access_token"`
+		TokenType   string `json:"token_type"`
+		ExpiresIn   int64  `json:"expires_in"`
+		IDToken     string `json:"id_token"`
+	}
+	expiresIn := int64(60)
+	type MyCustomClaims struct {
+		Acr           string `json:"acr"`
+		Nonce         string `json:"nonce"`
+		Email         string `json:"email"`
+		EmailVerified bool   `json:"email_verified"`
+		GivenName     string `json:"given_name"`
+		FamilyName    string `json:"family_name"`
+		Birthdate     string `json:"birthdate"`
+		AtHash        string `json:"at_hash"`
+		CHash         string `json:"c_hash"`
+		jwt.StandardClaims
+	}
+	claims := MyCustomClaims{
+		"http://idmanagement.gov/ns/assurance/loa/1",
+		"fakenonce",
+		"timothy.spencer@gsa.gov",
+		true,
+		"",
+		"",
+		"",
+		"",
+		"",
+		jwt.StandardClaims{
+			Audience:  "Audience",
+			ExpiresAt: time.Now().Unix() + expiresIn,
+			Id:        "foo",
+			IssuedAt:  time.Now().Unix(),
+			Issuer:    "https://idp.int.login.gov",
+			NotBefore: time.Now().Unix() - 1,
+			Subject:   "b2d2d115-1d7e-4579-b9d6-f8e84f4f56ca",
+		},
+	}
+	idtoken := jwt.NewWithClaims(jwt.SigningMethodRS256, claims)
+	signedidtoken, err := idtoken.SignedString(serverkey.PrivKey)
+	assert.NoError(t, err)
+	body, err := json.Marshal(loginGovRedeemResponse{
+		AccessToken: "a1234",
+		TokenType:   "Bearer",
+		ExpiresIn:   expiresIn,
+		IDToken:     signedidtoken,
+	})
+	assert.NoError(t, err)
+	var server *httptest.Server
+	p.RedeemURL, server = newLoginGovServer(body)
+	defer server.Close()
+
+	// Set up the user endpoint here
+	type loginGovUserResponse struct {
+		Email         string `json:"email"`
+		EmailVerified bool   `json:"email_verified"`
+		Subject       string `json:"sub"`
+	}
+	userbody, err := json.Marshal(loginGovUserResponse{
+		Email:         "timothy.spencer@gsa.gov",
+		EmailVerified: true,
+		Subject:       "b2d2d115-1d7e-4579-b9d6-f8e84f4f56ca",
+	})
+	assert.NoError(t, err)
+	var userserver *httptest.Server
+	p.ProfileURL, userserver = newLoginGovServer(userbody)
+	defer userserver.Close()
+
+	// Set up the PubJWKURL endpoint here used to verify the JWT
+	var pubkeys jose.JSONWebKeySet
+	pubkeys.Keys = append(pubkeys.Keys, serverkey.PubJWK)
+	pubjwkbody, err := json.Marshal(pubkeys)
+	assert.NoError(t, err)
+	var pubjwkserver *httptest.Server
+	p.PubJWKURL, pubjwkserver = newLoginGovServer(pubjwkbody)
+	defer pubjwkserver.Close()
+
+	session, err := p.Redeem("http://redirect/", "code1234")
+	assert.NoError(t, err)
+	assert.NotEqual(t, session, nil)
+	assert.Equal(t, "timothy.spencer@gsa.gov", session.Email)
+	assert.Equal(t, "a1234", session.AccessToken)
+
+	// The test ought to run in under 2 seconds.  If not, you may need to bump this up.
+	assert.InDelta(t, session.ExpiresOn.Unix(), time.Now().Unix()+expiresIn, 2)
+}
+
+func TestLoginGovProviderBadNonce(t *testing.T) {
+	p, serverkey, err := newLoginGovProvider()
+	assert.NotEqual(t, nil, p)
+	assert.NoError(t, err)
+
+	// Set up the redeem endpoint here
+	type loginGovRedeemResponse struct {
+		AccessToken string `json:"access_token"`
+		TokenType   string `json:"token_type"`
+		ExpiresIn   int64  `json:"expires_in"`
+		IDToken     string `json:"id_token"`
+	}
+	expiresIn := int64(60)
+	type MyCustomClaims struct {
+		Acr           string `json:"acr"`
+		Nonce         string `json:"nonce"`
+		Email         string `json:"email"`
+		EmailVerified bool   `json:"email_verified"`
+		GivenName     string `json:"given_name"`
+		FamilyName    string `json:"family_name"`
+		Birthdate     string `json:"birthdate"`
+		AtHash        string `json:"at_hash"`
+		CHash         string `json:"c_hash"`
+		jwt.StandardClaims
+	}
+	claims := MyCustomClaims{
+		"http://idmanagement.gov/ns/assurance/loa/1",
+		"badfakenonce",
+		"timothy.spencer@gsa.gov",
+		true,
+		"",
+		"",
+		"",
+		"",
+		"",
+		jwt.StandardClaims{
+			Audience:  "Audience",
+			ExpiresAt: time.Now().Unix() + expiresIn,
+			Id:        "foo",
+			IssuedAt:  time.Now().Unix(),
+			Issuer:    "https://idp.int.login.gov",
+			NotBefore: time.Now().Unix() - 1,
+			Subject:   "b2d2d115-1d7e-4579-b9d6-f8e84f4f56ca",
+		},
+	}
+	idtoken := jwt.NewWithClaims(jwt.SigningMethodRS256, claims)
+	signedidtoken, err := idtoken.SignedString(serverkey.PrivKey)
+	assert.NoError(t, err)
+	body, err := json.Marshal(loginGovRedeemResponse{
+		AccessToken: "a1234",
+		TokenType:   "Bearer",
+		ExpiresIn:   expiresIn,
+		IDToken:     signedidtoken,
+	})
+	assert.NoError(t, err)
+	var server *httptest.Server
+	p.RedeemURL, server = newLoginGovServer(body)
+	defer server.Close()
+
+	// Set up the user endpoint here
+	type loginGovUserResponse struct {
+		Email         string `json:"email"`
+		EmailVerified bool   `json:"email_verified"`
+		Subject       string `json:"sub"`
+	}
+	userbody, err := json.Marshal(loginGovUserResponse{
+		Email:         "timothy.spencer@gsa.gov",
+		EmailVerified: true,
+		Subject:       "b2d2d115-1d7e-4579-b9d6-f8e84f4f56ca",
+	})
+	assert.NoError(t, err)
+	var userserver *httptest.Server
+	p.ProfileURL, userserver = newLoginGovServer(userbody)
+	defer userserver.Close()
+
+	// Set up the PubJWKURL endpoint here used to verify the JWT
+	var pubkeys jose.JSONWebKeySet
+	pubkeys.Keys = append(pubkeys.Keys, serverkey.PubJWK)
+	pubjwkbody, err := json.Marshal(pubkeys)
+	assert.NoError(t, err)
+	var pubjwkserver *httptest.Server
+	p.PubJWKURL, pubjwkserver = newLoginGovServer(pubjwkbody)
+	defer pubjwkserver.Close()
+
+	_, err = p.Redeem("http://redirect/", "code1234")
+
+	// The "badfakenonce" in the idtoken above should cause this to error out
+	assert.Error(t, err)
+}

providers/providers.go

@@ -33,6 +33,8 @@ func New(provider string, p *ProviderData) Provider {
 		return NewGitLabProvider(p)
 	case "oidc":
 		return NewOIDCProvider(p)
+	case "login.gov":
+		return NewLoginGovProvider(p)
 	default:
 		return NewGoogleProvider(p)
 	}