vendor: golang.org/x/oauth2@latest

go get golang.org/x/oauth2@latest
go mod tidy
go mod vendor

go.mod

@@ -125,7 +125,7 @@ require (
 	go.uber.org/zap v1.9.1 // indirect
 	golang.org/x/crypto v0.0.0-20181127143415-eb0de9b17e85
 	golang.org/x/net v0.0.0-20190213061140-3a22650c66bd
-	golang.org/x/oauth2 v0.0.0-20181203162652-d668ce993890
+	golang.org/x/oauth2 v0.0.0-20190220154721-9b3c75971fc9
 	google.golang.org/api v0.1.0
 	google.golang.org/grpc v1.18.0
 	gopkg.in/vmihailenco/msgpack.v2 v2.9.1 // indirect

go.sum

@@ -1,6 +1,7 @@
 cloud.google.com/go v0.26.0 h1:e0WKqKTd5BnrG8aKH3J3h+QvEIQtSUcf2n5UZ5ZgLtQ=
 cloud.google.com/go v0.26.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMTw=
 cloud.google.com/go v0.31.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMTw=
+cloud.google.com/go v0.34.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMTw=
 cloud.google.com/go v0.36.0 h1:+aCSj7tOo2LODWVEuZDZeGCckdt6MlSF+X/rB3wUiS8=
 cloud.google.com/go v0.36.0/go.mod h1:RUoy9p/M4ge0HzT8L+SDZ8jg+Q6fth0CiBuhFJpSV40=
 dmitri.shuralyov.com/app/changes v0.0.0-20180602232624-0a106ad413e3/go.mod h1:Yl+fi1br7+Rr3LqpNJf1/uxUdtRUV+Tnj0o93V2B9MU=
@@ -403,12 +404,15 @@ golang.org/x/net v0.0.0-20181029044818-c44066c5c816/go.mod h1:mL1N/T3taQHkDXs73r
 golang.org/x/net v0.0.0-20181106065722-10aee1819953/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20181129055619-fae4c4e3ad76 h1:xx5MUFyRQRbPk6VjWjIE1epE/K5AoDD8QUN116NCy8k=
 golang.org/x/net v0.0.0-20181129055619-fae4c4e3ad76/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/net v0.0.0-20190108225652-1e06a53dbb7e/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20190213061140-3a22650c66bd h1:HuTn7WObtcDo9uEEU7rEqL0jYthdXAmZ6PP+meazmaU=
 golang.org/x/net v0.0.0-20190213061140-3a22650c66bd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
 golang.org/x/oauth2 v0.0.0-20181017192945-9dcd33a902f4/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
 golang.org/x/oauth2 v0.0.0-20181203162652-d668ce993890 h1:uESlIz09WIHT2I+pasSXcpLYqYK8wHcdCetU3VuMBJE=
 golang.org/x/oauth2 v0.0.0-20181203162652-d668ce993890/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
+golang.org/x/oauth2 v0.0.0-20190220154721-9b3c75971fc9 h1:pfyU+l9dEu0vZzDDMsdAKa1gZbJYEn6urYXj/+Xkz7s=
+golang.org/x/oauth2 v0.0.0-20190220154721-9b3c75971fc9/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
 golang.org/x/perf v0.0.0-20180704124530-6e6d33e29852/go.mod h1:JLpeXjPJfIyPr5TlbXLkXWLhP8nz10XfvxElABhCtcw=
 golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
@@ -437,6 +441,8 @@ google.golang.org/appengine v1.1.0/go.mod h1:EbEs0AVv82hx2wNQdGPgUI5lhzA/G0D9Ywl
 google.golang.org/appengine v1.2.0/go.mod h1:xpcJRLb0r/rnEns0DIKYYv+WjYCduHsrkT7/EB5XEv4=
 google.golang.org/appengine v1.3.0 h1:FBSsiFRMz3LBeXIomRnVzrQwSDj4ibvcRexLG0LZGQk=
 google.golang.org/appengine v1.3.0/go.mod h1:xpcJRLb0r/rnEns0DIKYYv+WjYCduHsrkT7/EB5XEv4=
+google.golang.org/appengine v1.4.0 h1:/wp5JvzpHIxhs/dumFmF7BXTf3Z+dd4uXta4kVyO508=
+google.golang.org/appengine v1.4.0/go.mod h1:xpcJRLb0r/rnEns0DIKYYv+WjYCduHsrkT7/EB5XEv4=
 google.golang.org/genproto v0.0.0-20180817151627-c66870c02cf8/go.mod h1:JiN7NxoALGmiZfu7CAH4rXhgtRTLTxftemlI0sWmxmc=
 google.golang.org/genproto v0.0.0-20180831171423-11092d34479b h1:lohp5blsw53GBXtLyLNaTXPXS9pJ1tiTw61ZHUoE9Qw=
 google.golang.org/genproto v0.0.0-20180831171423-11092d34479b/go.mod h1:JiN7NxoALGmiZfu7CAH4rXhgtRTLTxftemlI0sWmxmc=

vendor/golang.org/x/oauth2/README.md

@@ -19,57 +19,6 @@ See godoc for further documentation and examples.
 * [godoc.org/golang.org/x/oauth2](http://godoc.org/golang.org/x/oauth2)
 * [godoc.org/golang.org/x/oauth2/google](http://godoc.org/golang.org/x/oauth2/google)
 
-
-## App Engine
-
-In change 96e89be (March 2015), we removed the `oauth2.Context2` type in favor
-of the [`context.Context`](https://golang.org/x/net/context#Context) type from
-the `golang.org/x/net/context` package. Later replaced by the standard `context` package
-of the [`context.Context`](https://golang.org/pkg/context#Context) type.
-
-
-This means it's no longer possible to use the "Classic App Engine"
-`appengine.Context` type with the `oauth2` package. (You're using
-Classic App Engine if you import the package `"appengine"`.)
-
-To work around this, you may use the new `"google.golang.org/appengine"`
-package. This package has almost the same API as the `"appengine"` package,
-but it can be fetched with `go get` and used on "Managed VMs" and well as
-Classic App Engine.
-
-See the [new `appengine` package's readme](https://github.com/golang/appengine#updating-a-go-app-engine-app)
-for information on updating your app.
-
-If you don't want to update your entire app to use the new App Engine packages,
-you may use both sets of packages in parallel, using only the new packages
-with the `oauth2` package.
-
-```go
-import (
-	"context"
-	"golang.org/x/oauth2"
-	"golang.org/x/oauth2/google"
-	newappengine "google.golang.org/appengine"
-	newurlfetch "google.golang.org/appengine/urlfetch"
-
-	"appengine"
-)
-
-func handler(w http.ResponseWriter, r *http.Request) {
-	var c appengine.Context = appengine.NewContext(r)
-	c.Infof("Logging a message with the old package")
-
-	var ctx context.Context = newappengine.NewContext(r)
-	client := &http.Client{
-		Transport: &oauth2.Transport{
-			Source: google.AppEngineTokenSource(ctx, "scope"),
-			Base:   &newurlfetch.Transport{Context: ctx},
-		},
-	}
-	client.Get("...")
-}
-```
-
 ## Policy for new packages
 
 We no longer accept new provider-specific packages in this repo. For

vendor/golang.org/x/oauth2/go.mod

@@ -0,0 +1,10 @@
+module golang.org/x/oauth2
+
+go 1.11
+
+require (
+	cloud.google.com/go v0.34.0
+	golang.org/x/net v0.0.0-20190108225652-1e06a53dbb7e
+	golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4 // indirect
+	google.golang.org/appengine v1.4.0
+)

vendor/golang.org/x/oauth2/go.sum

@@ -0,0 +1,12 @@
+cloud.google.com/go v0.34.0 h1:eOI3/cP2VTU6uZLDYAoic+eyzzB9YyGmJ7eIjl8rOPg=
+cloud.google.com/go v0.34.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMTw=
+github.com/golang/protobuf v1.2.0 h1:P3YflyNX/ehuJFLhxviNdFxQPkGK5cDcApsge1SqnvM=
+github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/net v0.0.0-20190108225652-1e06a53dbb7e h1:bRhVy7zSSasaqNksaRZiA5EEI+Ei4I1nO5Jh72wfHlg=
+golang.org/x/net v0.0.0-20190108225652-1e06a53dbb7e/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4 h1:YUO/7uOKsKeq9UokNS62b8FYywz3ker1l1vDZRCRefw=
+golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+google.golang.org/appengine v1.4.0 h1:/wp5JvzpHIxhs/dumFmF7BXTf3Z+dd4uXta4kVyO508=
+google.golang.org/appengine v1.4.0/go.mod h1:xpcJRLb0r/rnEns0DIKYYv+WjYCduHsrkT7/EB5XEv4=

vendor/golang.org/x/oauth2/google/google.go

@@ -21,6 +21,7 @@ import (
 var Endpoint = oauth2.Endpoint{
 	AuthURL:   "https://accounts.google.com/o/oauth2/auth",
 	TokenURL:  "https://accounts.google.com/o/oauth2/token",
+	AuthStyle: oauth2.AuthStyleInParams,
 }
 
 // JWTTokenURL is Google's OAuth 2.0 token URL to use with the JWT flow.

vendor/golang.org/x/oauth2/internal/token.go

@@ -16,6 +16,7 @@ import (
 	"net/url"
 	"strconv"
 	"strings"
+	"sync"
 	"time"
 
 	"golang.org/x/net/context/ctxhttp"
@@ -77,6 +78,9 @@ func (e *tokenJSON) expiry() (t time.Time) {
 type expirationTime int32
 
 func (e *expirationTime) UnmarshalJSON(b []byte) error {
+	if len(b) == 0 || string(b) == "null" {
+		return nil
+	}
 	var n json.Number
 	err := json.Unmarshal(b, &n)
 	if err != nil {
@@ -90,102 +94,71 @@ func (e *expirationTime) UnmarshalJSON(b []byte) error {
 	return nil
 }
 
-var brokenAuthHeaderProviders = []string{
+// RegisterBrokenAuthHeaderProvider previously did something. It is now a no-op.
-	"https://accounts.google.com/",
+//
-	"https://api.codeswholesale.com/oauth/token",
+// Deprecated: this function no longer does anything. Caller code that
-	"https://api.dropbox.com/",
+// wants to avoid potential extra HTTP requests made during
-	"https://api.dropboxapi.com/",
+// auto-probing of the provider's auth style should set
-	"https://api.instagram.com/",
+// Endpoint.AuthStyle.
-	"https://api.netatmo.net/",
+func RegisterBrokenAuthHeaderProvider(tokenURL string) {}
-	"https://api.odnoklassniki.ru/",
+
-	"https://api.pushbullet.com/",
+// AuthStyle is a copy of the golang.org/x/oauth2 package's AuthStyle type.
-	"https://api.soundcloud.com/",
+type AuthStyle int
-	"https://api.twitch.tv/",
+
-	"https://id.twitch.tv/",
+const (
-	"https://app.box.com/",
+	AuthStyleUnknown  AuthStyle = 0
-	"https://api.box.com/",
+	AuthStyleInParams AuthStyle = 1
-	"https://connect.stripe.com/",
+	AuthStyleInHeader AuthStyle = 2
-	"https://login.mailchimp.com/",
+)
-	"https://login.microsoftonline.com/",
+
-	"https://login.salesforce.com/",
+// authStyleCache is the set of tokenURLs we've successfully used via
-	"https://login.windows.net",
+// RetrieveToken and which style auth we ended up using.
-	"https://login.live.com/",
+// It's called a cache, but it doesn't (yet?) shrink. It's expected that
-	"https://login.live-int.com/",
+// the set of OAuth2 servers a program contacts over time is fixed and
-	"https://oauth.sandbox.trainingpeaks.com/",
+// small.
-	"https://oauth.trainingpeaks.com/",
+var authStyleCache struct {
-	"https://oauth.vk.com/",
+	sync.Mutex
-	"https://openapi.baidu.com/",
+	m map[string]AuthStyle // keyed by tokenURL
-	"https://slack.com/",
-	"https://test-sandbox.auth.corp.google.com",
-	"https://test.salesforce.com/",
-	"https://user.gini.net/",
-	"https://www.douban.com/",
-	"https://www.googleapis.com/",
-	"https://www.linkedin.com/",
-	"https://www.strava.com/oauth/",
-	"https://www.wunderlist.com/oauth/",
-	"https://api.patreon.com/",
-	"https://sandbox.codeswholesale.com/oauth/token",
-	"https://api.sipgate.com/v1/authorization/oauth",
-	"https://api.medium.com/v1/tokens",
-	"https://log.finalsurge.com/oauth/token",
-	"https://multisport.todaysplan.com.au/rest/oauth/access_token",
-	"https://whats.todaysplan.com.au/rest/oauth/access_token",
-	"https://stackoverflow.com/oauth/access_token",
-	"https://account.health.nokia.com",
-	"https://accounts.zoho.com",
-	"https://gitter.im/login/oauth/token",
-	"https://openid-connect.onelogin.com/oidc",
-	"https://api.dailymotion.com/oauth/token",
 }
 
-// brokenAuthHeaderDomains lists broken providers that issue dynamic endpoints.
+// ResetAuthCache resets the global authentication style cache used
-var brokenAuthHeaderDomains = []string{
+// for AuthStyleUnknown token requests.
-	".auth0.com",
+func ResetAuthCache() {
-	".force.com",
+	authStyleCache.Lock()
-	".myshopify.com",
+	defer authStyleCache.Unlock()
-	".okta.com",
+	authStyleCache.m = nil
-	".oktapreview.com",
 }
 
-func RegisterBrokenAuthHeaderProvider(tokenURL string) {
+// lookupAuthStyle reports which auth style we last used with tokenURL
-	brokenAuthHeaderProviders = append(brokenAuthHeaderProviders, tokenURL)
+// when calling RetrieveToken and whether we have ever done so.
+func lookupAuthStyle(tokenURL string) (style AuthStyle, ok bool) {
+	authStyleCache.Lock()
+	defer authStyleCache.Unlock()
+	style, ok = authStyleCache.m[tokenURL]
+	return
 }
 
-// providerAuthHeaderWorks reports whether the OAuth2 server identified by the tokenURL
+// setAuthStyle adds an entry to authStyleCache, documented above.
-// implements the OAuth2 spec correctly
+func setAuthStyle(tokenURL string, v AuthStyle) {
-// See https://code.google.com/p/goauth2/issues/detail?id=31 for background.
+	authStyleCache.Lock()
-// In summary:
+	defer authStyleCache.Unlock()
-// - Reddit only accepts client secret in the Authorization header
+	if authStyleCache.m == nil {
-// - Dropbox accepts either it in URL param or Auth header, but not both.
+		authStyleCache.m = make(map[string]AuthStyle)
-// - Google only accepts URL param (not spec compliant?), not Auth header
-// - Stripe only accepts client secret in Auth header with Bearer method, not Basic
-func providerAuthHeaderWorks(tokenURL string) bool {
-	for _, s := range brokenAuthHeaderProviders {
-		if strings.HasPrefix(tokenURL, s) {
-			// Some sites fail to implement the OAuth2 spec fully.
-			return false
 	}
-	}
+	authStyleCache.m[tokenURL] = v
-
-	if u, err := url.Parse(tokenURL); err == nil {
-		for _, s := range brokenAuthHeaderDomains {
-			if strings.HasSuffix(u.Host, s) {
-				return false
-			}
-		}
-	}
-
-	// Assume the provider implements the spec properly
-	// otherwise. We can add more exceptions as they're
-	// discovered. We will _not_ be adding configurable hooks
-	// to this package to let users select server bugs.
-	return true
 }
 
-func RetrieveToken(ctx context.Context, clientID, clientSecret, tokenURL string, v url.Values) (*Token, error) {
+// newTokenRequest returns a new *http.Request to retrieve a new token
-	bustedAuth := !providerAuthHeaderWorks(tokenURL)
+// from tokenURL using the provided clientID, clientSecret, and POST
-	if bustedAuth {
+// body parameters.
+//
+// inParams is whether the clientID & clientSecret should be encoded
+// as the POST body. An 'inParams' value of true means to send it in
+// the POST body (along with any values in v); false means to send it
+// in the Authorization header.
+func newTokenRequest(tokenURL, clientID, clientSecret string, v url.Values, authStyle AuthStyle) (*http.Request, error) {
+	if authStyle == AuthStyleInParams {
+		v = cloneURLValues(v)
 		if clientID != "" {
 			v.Set("client_id", clientID)
 		}
@@ -198,15 +171,70 @@ func RetrieveToken(ctx context.Context, clientID, clientSecret, tokenURL string,
 		return nil, err
 	}
 	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
-	if !bustedAuth {
+	if authStyle == AuthStyleInHeader {
 		req.SetBasicAuth(url.QueryEscape(clientID), url.QueryEscape(clientSecret))
 	}
+	return req, nil
+}
+
+func cloneURLValues(v url.Values) url.Values {
+	v2 := make(url.Values, len(v))
+	for k, vv := range v {
+		v2[k] = append([]string(nil), vv...)
+	}
+	return v2
+}
+
+func RetrieveToken(ctx context.Context, clientID, clientSecret, tokenURL string, v url.Values, authStyle AuthStyle) (*Token, error) {
+	needsAuthStyleProbe := authStyle == 0
+	if needsAuthStyleProbe {
+		if style, ok := lookupAuthStyle(tokenURL); ok {
+			authStyle = style
+			needsAuthStyleProbe = false
+		} else {
+			authStyle = AuthStyleInHeader // the first way we'll try
+		}
+	}
+	req, err := newTokenRequest(tokenURL, clientID, clientSecret, v, authStyle)
+	if err != nil {
+		return nil, err
+	}
+	token, err := doTokenRoundTrip(ctx, req)
+	if err != nil && needsAuthStyleProbe {
+		// If we get an error, assume the server wants the
+		// clientID & clientSecret in a different form.
+		// See https://code.google.com/p/goauth2/issues/detail?id=31 for background.
+		// In summary:
+		// - Reddit only accepts client secret in the Authorization header
+		// - Dropbox accepts either it in URL param or Auth header, but not both.
+		// - Google only accepts URL param (not spec compliant?), not Auth header
+		// - Stripe only accepts client secret in Auth header with Bearer method, not Basic
+		//
+		// We used to maintain a big table in this code of all the sites and which way
+		// they went, but maintaining it didn't scale & got annoying.
+		// So just try both ways.
+		authStyle = AuthStyleInParams // the second way we'll try
+		req, _ = newTokenRequest(tokenURL, clientID, clientSecret, v, authStyle)
+		token, err = doTokenRoundTrip(ctx, req)
+	}
+	if needsAuthStyleProbe && err == nil {
+		setAuthStyle(tokenURL, authStyle)
+	}
+	// Don't overwrite `RefreshToken` with an empty value
+	// if this was a token refreshing request.
+	if token != nil && token.RefreshToken == "" {
+		token.RefreshToken = v.Get("refresh_token")
+	}
+	return token, err
+}
+
+func doTokenRoundTrip(ctx context.Context, req *http.Request) (*Token, error) {
 	r, err := ctxhttp.Do(ctx, ContextClient(ctx), req)
 	if err != nil {
 		return nil, err
 	}
-	defer r.Body.Close()
 	body, err := ioutil.ReadAll(io.LimitReader(r.Body, 1<<20))
+	r.Body.Close()
 	if err != nil {
 		return nil, fmt.Errorf("oauth2: cannot fetch token: %v", err)
 	}
@@ -232,7 +260,7 @@ func RetrieveToken(ctx context.Context, clientID, clientSecret, tokenURL string,
 			Raw:          vals,
 		}
 		e := vals.Get("expires_in")
-		if e == "" {
+		if e == "" || e == "null" {
 			// TODO(jbd): Facebook's OAuth2 implementation is broken and
 			// returns expires_in field in expires. Remove the fallback to expires,
 			// when Facebook fixes their implementation.
@@ -256,13 +284,8 @@ func RetrieveToken(ctx context.Context, clientID, clientSecret, tokenURL string,
 		}
 		json.Unmarshal(body, &token.Raw) // no error checks for optional fields
 	}
-	// Don't overwrite `RefreshToken` with an empty value
-	// if this was a token refreshing request.
-	if token.RefreshToken == "" {
-		token.RefreshToken = v.Get("refresh_token")
-	}
 	if token.AccessToken == "" {
-		return token, errors.New("oauth2: server response missing access_token")
+		return nil, errors.New("oauth2: server response missing access_token")
 	}
 	return token, nil
 }

vendor/golang.org/x/oauth2/jwt/jwt.go

@@ -61,6 +61,11 @@ type Config struct {
 
 	// Expires optionally specifies how long the token is valid for.
 	Expires time.Duration
+
+	// Audience optionally specifies the intended audience of the
+	// request.  If empty, the value of TokenURL is used as the
+	// intended audience.
+	Audience string
 }
 
 // TokenSource returns a JWT TokenSource using the configuration
@@ -105,6 +110,9 @@ func (js jwtSource) Token() (*oauth2.Token, error) {
 	if t := js.conf.Expires; t > 0 {
 		claimSet.Exp = time.Now().Add(t).Unix()
 	}
+	if aud := js.conf.Audience; aud != "" {
+		claimSet.Aud = aud
+	}
 	h := *defaultHeader
 	h.KeyID = js.conf.PrivateKeyID
 	payload, err := jws.Encode(&h, claimSet, pk)

vendor/golang.org/x/oauth2/oauth2.go

@@ -26,17 +26,13 @@ import (
 // Deprecated: Use context.Background() or context.TODO() instead.
 var NoContext = context.TODO()
 
-// RegisterBrokenAuthHeaderProvider registers an OAuth2 server
+// RegisterBrokenAuthHeaderProvider previously did something. It is now a no-op.
-// identified by the tokenURL prefix as an OAuth2 implementation
+//
-// which doesn't support the HTTP Basic authentication
+// Deprecated: this function no longer does anything. Caller code that
-// scheme to authenticate with the authorization server.
+// wants to avoid potential extra HTTP requests made during
-// Once a server is registered, credentials (client_id and client_secret)
+// auto-probing of the provider's auth style should set
-// will be passed as query parameters rather than being present
+// Endpoint.AuthStyle.
-// in the Authorization header.
+func RegisterBrokenAuthHeaderProvider(tokenURL string) {}
-// See https://code.google.com/p/goauth2/issues/detail?id=31 for background.
-func RegisterBrokenAuthHeaderProvider(tokenURL string) {
-	internal.RegisterBrokenAuthHeaderProvider(tokenURL)
-}
 
 // Config describes a typical 3-legged OAuth2 flow, with both the
 // client application information and the server's endpoint URLs.
@@ -71,13 +67,38 @@ type TokenSource interface {
 	Token() (*Token, error)
 }
 
-// Endpoint contains the OAuth 2.0 provider's authorization and token
+// Endpoint represents an OAuth 2.0 provider's authorization and token
 // endpoint URLs.
 type Endpoint struct {
 	AuthURL  string
 	TokenURL string
+
+	// AuthStyle optionally specifies how the endpoint wants the
+	// client ID & client secret sent. The zero value means to
+	// auto-detect.
+	AuthStyle AuthStyle
 }
 
+// AuthStyle represents how requests for tokens are authenticated
+// to the server.
+type AuthStyle int
+
+const (
+	// AuthStyleAutoDetect means to auto-detect which authentication
+	// style the provider wants by trying both ways and caching
+	// the successful way for the future.
+	AuthStyleAutoDetect AuthStyle = 0
+
+	// AuthStyleInParams sends the "client_id" and "client_secret"
+	// in the POST body as application/x-www-form-urlencoded parameters.
+	AuthStyleInParams AuthStyle = 1
+
+	// AuthStyleInHeader sends the client_id and client_password
+	// using HTTP Basic Authorization. This is an optional style
+	// described in the OAuth2 RFC 6749 section 2.3.1.
+	AuthStyleInHeader AuthStyle = 2
+)
+
 var (
 	// AccessTypeOnline and AccessTypeOffline are options passed
 	// to the Options.AuthCodeURL method. They modify the
@@ -124,7 +145,7 @@ func SetAuthURLParam(key, value string) AuthCodeOption {
 //
 // Opts may include AccessTypeOnline or AccessTypeOffline, as well
 // as ApprovalForce.
-// It can also be used to pass the PKCE challange.
+// It can also be used to pass the PKCE challenge.
 // See https://www.oauth.com/oauth2-servers/pkce/ for more info.
 func (c *Config) AuthCodeURL(state string, opts ...AuthCodeOption) string {
 	var buf bytes.Buffer

vendor/golang.org/x/oauth2/token.go

@@ -118,13 +118,16 @@ func (t *Token) Extra(key string) interface{} {
 	return v
 }
 
+// timeNow is time.Now but pulled out as a variable for tests.
+var timeNow = time.Now
+
 // expired reports whether the token is expired.
 // t must be non-nil.
 func (t *Token) expired() bool {
 	if t.Expiry.IsZero() {
 		return false
 	}
-	return t.Expiry.Round(0).Add(-expiryDelta).Before(time.Now())
+	return t.Expiry.Round(0).Add(-expiryDelta).Before(timeNow())
 }
 
 // Valid reports whether t is non-nil, has an AccessToken, and is not expired.
@@ -151,7 +154,7 @@ func tokenFromInternal(t *internal.Token) *Token {
 // This token is then mapped from *internal.Token into an *oauth2.Token which is returned along
 // with an error..
 func retrieveToken(ctx context.Context, c *Config, v url.Values) (*Token, error) {
-	tk, err := internal.RetrieveToken(ctx, c.ClientID, c.ClientSecret, c.Endpoint.TokenURL, v)
+	tk, err := internal.RetrieveToken(ctx, c.ClientID, c.ClientSecret, c.Endpoint.TokenURL, v, internal.AuthStyle(c.Endpoint.AuthStyle))
 	if err != nil {
 		if rErr, ok := err.(*internal.RetrieveError); ok {
 			return nil, (*RetrieveError)(rErr)

vendor/google.golang.org/appengine/appengine.go

@@ -78,6 +78,12 @@ func IsAppEngine() bool {
 	return internal.IsAppEngine()
 }
 
+// IsSecondGen reports whether the App Engine app is running on the second generation
+// runtimes (>= Go 1.11).
+func IsSecondGen() bool {
+	return internal.IsSecondGen()
+}
+
 // NewContext returns a context for an in-flight HTTP request.
 // This function is cheap.
 func NewContext(req *http.Request) context.Context {

vendor/google.golang.org/appengine/internal/api.go

@@ -579,7 +579,10 @@ func logf(c *context, level int64, format string, args ...interface{}) {
 		Level:         &level,
 		Message:       &s,
 	})
+	// Only duplicate log to stderr if not running on App Engine second generation
+	if !IsSecondGen() {
 		log.Print(logLevelName[level] + ": " + s)
+	}
 }
 
 // flushLog attempts to flush any pending logs to the appserver.

vendor/google.golang.org/appengine/internal/identity.go

@@ -31,9 +31,15 @@ func AppID(c netcontext.Context) string {
 // ../appengine.go. See that file for commentary.
 func IsStandard() bool {
 	// appengineStandard will be true for first-gen runtimes (<= Go 1.9) but not
-	// second-gen (>= Go 1.11). Second-gen runtimes set $GAE_ENV so we use that
+	// second-gen (>= Go 1.11).
-	// to check if we're on a second-gen runtime.
+	return appengineStandard || IsSecondGen()
-	return appengineStandard || os.Getenv("GAE_ENV") == "standard"
+}
+
+// IsStandard is the implementation of the wrapper function of the same name in
+// ../appengine.go. See that file for commentary.
+func IsSecondGen() bool {
+	// Second-gen runtimes set $GAE_ENV so we use that to check if we're on a second-gen runtime.
+	return os.Getenv("GAE_ENV") == "standard"
 }
 
 // IsFlex is the implementation of the wrapper function of the same name in

vendor/google.golang.org/appengine/internal/main.go

@@ -11,5 +11,6 @@ import (
 )
 
 func Main() {
+	MainPath = ""
 	appengine_internal.Main()
 }

vendor/google.golang.org/appengine/internal/main_common.go

@@ -0,0 +1,7 @@
+package internal
+
+// MainPath stores the file path of the main package. On App Engine Standard
+// using Go version 1.9 and below, this will be unset. On App Engine Flex and
+// App Engine Standard second-gen (Go 1.11 and above), this will be the
+// filepath to package main.
+var MainPath string

vendor/google.golang.org/appengine/internal/main_vm.go

@@ -12,9 +12,12 @@ import (
 	"net/http"
 	"net/url"
 	"os"
+	"path/filepath"
+	"runtime"
 )
 
 func Main() {
+	MainPath = filepath.Dir(findMainPath())
 	installHealthChecker(http.DefaultServeMux)
 
 	port := "8080"
@@ -31,6 +34,24 @@ func Main() {
 	}
 }
 
+// Find the path to package main by looking at the root Caller.
+func findMainPath() string {
+	pc := make([]uintptr, 100)
+	n := runtime.Callers(2, pc)
+	frames := runtime.CallersFrames(pc[:n])
+	for {
+		frame, more := frames.Next()
+		// Tests won't have package main, instead they have testing.tRunner
+		if frame.Function == "main.main" || frame.Function == "testing.tRunner" {
+			return frame.File
+		}
+		if !more {
+			break
+		}
+	}
+	return ""
+}
+
 func installHealthChecker(mux *http.ServeMux) {
 	// If no health check handler has been installed by this point, add a trivial one.
 	const healthPath = "/_ah/health"

vendor/modules.txt

@@ -490,7 +490,7 @@ golang.org/x/net/http2/hpack
 golang.org/x/net/html
 golang.org/x/net/http/httpguts
 golang.org/x/net/html/atom
-# golang.org/x/oauth2 v0.0.0-20181203162652-d668ce993890
+# golang.org/x/oauth2 v0.0.0-20190220154721-9b3c75971fc9
 golang.org/x/oauth2/jwt
 golang.org/x/oauth2
 golang.org/x/oauth2/internal
@@ -532,7 +532,7 @@ google.golang.org/api/googleapi/internal/uritemplates
 google.golang.org/api/gensupport
 google.golang.org/api/googleapi/transport
 google.golang.org/api/transport/http/internal/propagation
-# google.golang.org/appengine v1.3.0
+# google.golang.org/appengine v1.4.0
 google.golang.org/appengine/urlfetch
 google.golang.org/appengine
 google.golang.org/appengine/datastore