Customise Authorization header

clientcredentials/clientcredentials.go

@@ -51,6 +51,12 @@ type Config struct {
 	// authStyleCache caches which auth style to use when Endpoint.AuthStyle is
 	// the zero value (AuthStyleAutoDetect).
 	authStyleCache internal.LazyAuthStyleCache
+
+	// CustomTokenHeaderKey - If set, Instead of `Authorization` this will be used as header key
+	CustomTokenHeaderKey string
+
+	// CustomTokenPrefix - If set, Instead of `Bearer ` prefix / token type retrieved, this will be used
+	CustomTokenPrefix string
 }
 
 // Token uses client credentials to retrieve a token.
@@ -120,5 +126,7 @@ func (c *tokenSource) Token() (*oauth2.Token, error) {
 		RefreshToken: tk.RefreshToken,
 		Expiry:       tk.Expiry,
 	}
+	t.CustomTokenHeaderKey = c.conf.CustomTokenHeaderKey
+	t.CustomTokenPrefix = c.conf.CustomTokenPrefix
 	return t.WithExtra(tk.Raw), nil
 }

jwt/jwt.go

@@ -74,6 +74,12 @@ type Config struct {
 	// UseIDToken optionally specifies whether ID token should be used instead
 	// of access token when the server returns both.
 	UseIDToken bool
+
+	// CustomTokenHeaderKey - If set, Instead of `Authorization` this will be used as header key
+	CustomTokenHeaderKey string
+
+	// CustomTokenPrefix - If set, Instead of `Bearer ` prefix / token type retrieved, this will be used
+	CustomTokenPrefix string
 }
 
 // TokenSource returns a JWT TokenSource using the configuration
@@ -181,5 +187,7 @@ func (js jwtSource) Token() (*oauth2.Token, error) {
 		}
 		token.AccessToken = tokenRes.IDToken
 	}
+	token.CustomTokenHeaderKey = js.conf.CustomTokenHeaderKey
+	token.CustomTokenPrefix = js.conf.CustomTokenPrefix
 	return token, nil
 }

token.go

@@ -64,10 +64,19 @@ type Token struct {
 	// expired, by subtracting from Expiry. If zero, defaultExpiryDelta
 	// is used.
 	expiryDelta time.Duration
+
+	// CustomTokenHeaderKey - If set, Instead of `Authorization` this will be used as header key
+	CustomTokenHeaderKey string
+
+	// CustomTokenPrefix - If set, Instead of `Bearer ` prefix / token type retrieved, this will be used
+	CustomTokenPrefix string
 }
 
 // Type returns t.TokenType if non-empty, else "Bearer".
 func (t *Token) Type() string {
+	if t.CustomTokenPrefix != "" {
+		return ""
+	}
 	if strings.EqualFold(t.TokenType, "bearer") {
 		return "Bearer"
 	}
@@ -89,7 +98,15 @@ func (t *Token) Type() string {
 // This method is unnecessary when using Transport or an HTTP Client
 // returned by this package.
 func (t *Token) SetAuthHeader(r *http.Request) {
-	r.Header.Set("Authorization", t.Type()+" "+t.AccessToken)
+	headerKey := "Authorization"
+	if strings.TrimSpace(t.CustomTokenHeaderKey) != "" {
+		headerKey = t.CustomTokenHeaderKey
+	}
+	headerValue := t.Type() + " " + t.AccessToken
+	if t.CustomTokenPrefix != "" {
+		headerValue = t.CustomTokenPrefix + t.AccessToken
+	}
+	r.Header.Set(headerKey, strings.TrimSpace(headerValue))
 }
 
 // WithExtra returns a new Token that's a clone of t, but using the

token_test.go

@@ -71,6 +71,8 @@ func TestTokenTypeMethod(t *testing.T) {
 		{name: "mac", tok: &Token{TokenType: "mac"}, want: "MAC"},
 		{name: "mac-caps", tok: &Token{TokenType: "MAC"}, want: "MAC"},
 		{name: "mac-mixed_case", tok: &Token{TokenType: "mAc"}, want: "MAC"},
+		{name: "clear type", tok: &Token{TokenType: "Bearer", CustomTokenPrefix: " "}, want: ""},
+		{name: "custom type", tok: &Token{TokenType: "mAC", CustomTokenPrefix: "something"}, want: ""},
 	}
 	for _, tc := range cases {
 		if got, want := tc.tok.Type(), tc.want; got != want {