Fixes #4483: Add support for Authorization: Bearer token Header (#4502)

Added Authorization Bearer token support as per RFC6750

* appended Authorization header token parsing after X-Consul-Token
* added test cases
* updated website documentation to mention Authorization header

* improve tests, improve Bearer parsing

agent/http.go

@@ -563,15 +563,36 @@ func (s *HTTPServer) parseDC(req *http.Request, dc *string) {
 	}
 }
 
-// parseTokenInternal is used to parse the ?token query param or the X-Consul-Token header and
+// parseTokenInternal is used to parse the ?token query param or the X-Consul-Token header or
-// optionally resolve proxy tokens to real ACL tokens. If no token is specified it will populate
+// Authorization Bearer token (RFC6750) and
+// optionally resolve proxy tokens to real ACL tokens. If the token is invalid or not specified it will populate
 // the token with the agents UserToken (acl_token in the consul configuration)
+// Parsing has the following priority: ?token, X-Consul-Token and last "Authorization: Bearer "
 func (s *HTTPServer) parseTokenInternal(req *http.Request, token *string, resolveProxyToken bool) {
 	tok := ""
 	if other := req.URL.Query().Get("token"); other != "" {
 		tok = other
 	} else if other := req.Header.Get("X-Consul-Token"); other != "" {
 		tok = other
+	} else if other := req.Header.Get("Authorization"); other != "" {
+		// HTTP Authorization headers are in the format: <Scheme>[SPACE]<Value>
+		// Ref. https://tools.ietf.org/html/rfc7236#section-3
+		parts := strings.Split(other, " ")
+
+		// Authorization Header is invalid if containing 1 or 0 parts, e.g.:
+		// "" || "<Scheme><Value>" || "<Scheme>" || "<Value>"
+		if len(parts) > 1 {
+			scheme := parts[0]
+			// Everything after "<Scheme>" is "<Value>", trimmed
+			value := strings.TrimSpace(strings.Join(parts[1:], " "))
+
+			// <Scheme> must be "Bearer"
+			if scheme == "Bearer" {
+				// Since Bearer tokens shouldnt contain spaces (rfc6750#section-2.1)
+				// "value" is tokenized, only the first item is used
+				tok = strings.TrimSpace(strings.Split(value, " ")[0])
+			}
+		}
 	}
 
 	if tok != "" {
@@ -589,13 +610,14 @@ func (s *HTTPServer) parseTokenInternal(req *http.Request, token *string, resolv
 	*token = s.agent.tokens.UserToken()
 }
 
-// parseToken is used to parse the ?token query param or the X-Consul-Token header and
+// parseToken is used to parse the ?token query param or the X-Consul-Token header or
-// resolve proxy tokens to real ACL tokens
+// Authorization Bearer token header (RFC6750) and resolve proxy tokens to real ACL tokens
 func (s *HTTPServer) parseToken(req *http.Request, token *string) {
 	s.parseTokenInternal(req, token, true)
 }
 
 // parseTokenWithoutResolvingProxyToken is used to parse the ?token query param or the X-Consul-Token header
+// or Authorization Bearer header token (RFC6750) and
 func (s *HTTPServer) parseTokenWithoutResolvingProxyToken(req *http.Request, token *string) {
 	s.parseTokenInternal(req, token, false)
 }

agent/http_test.go

@@ -736,6 +736,40 @@ func TestACLResolution(t *testing.T) {
 	reqBothTokens, _ := http.NewRequest("GET", "/v1/catalog/nodes?token=baz", nil)
 	reqBothTokens.Header.Add("X-Consul-Token", "zap")
 
+	// Request with Authorization Bearer token
+	reqAuthBearerToken, _ := http.NewRequest("GET", "/v1/catalog/nodes", nil)
+	reqAuthBearerToken.Header.Add("Authorization", "Bearer bearer-token")
+
+	// Request with invalid Authorization scheme
+	reqAuthBearerInvalidScheme, _ := http.NewRequest("GET", "/v1/catalog/nodes", nil)
+	reqAuthBearerInvalidScheme.Header.Add("Authorization", "Beer")
+
+	// Request with empty Authorization Bearer token
+	reqAuthBearerTokenEmpty, _ := http.NewRequest("GET", "/v1/catalog/nodes", nil)
+	reqAuthBearerTokenEmpty.Header.Add("Authorization", "Bearer")
+
+	// Request with empty Authorization Bearer token
+	reqAuthBearerTokenInvalid, _ := http.NewRequest("GET", "/v1/catalog/nodes", nil)
+	reqAuthBearerTokenInvalid.Header.Add("Authorization", "Bearertoken")
+
+	// Request with more than one space between Bearer and token
+	reqAuthBearerTokenMultiSpaces, _ := http.NewRequest("GET", "/v1/catalog/nodes", nil)
+	reqAuthBearerTokenMultiSpaces.Header.Add("Authorization", "Bearer     bearer-token")
+
+	// Request with Authorization Bearer token containing spaces
+	reqAuthBearerTokenSpaces, _ := http.NewRequest("GET", "/v1/catalog/nodes", nil)
+	reqAuthBearerTokenSpaces.Header.Add("Authorization", "Bearer bearer-token "+
+		" the rest is discarded   ")
+
+	// Request with Authorization Bearer and querystring token
+	reqAuthBearerAndQsToken, _ := http.NewRequest("GET", "/v1/catalog/nodes?token=qstoken", nil)
+	reqAuthBearerAndQsToken.Header.Add("Authorization", "Bearer bearer-token")
+
+	// Request with Authorization Bearer and X-Consul-Token header token
+	reqAuthBearerAndXToken, _ := http.NewRequest("GET", "/v1/catalog/nodes", nil)
+	reqAuthBearerAndXToken.Header.Add("X-Consul-Token", "xtoken")
+	reqAuthBearerAndXToken.Header.Add("Authorization", "Bearer bearer-token")
+
 	a := NewTestAgent(t.Name(), "")
 	defer a.Shutdown()
 
@@ -770,6 +804,58 @@ func TestACLResolution(t *testing.T) {
 	if token != "baz" {
 		t.Fatalf("bad: %s", token)
 	}
+
+	//
+	// Authorization Bearer token tests
+	//
+
+	// Check if Authorization bearer token header is parsed correctly
+	a.srv.parseToken(reqAuthBearerToken, &token)
+	if token != "bearer-token" {
+		t.Fatalf("bad: %s", token)
+	}
+
+	// Check Authorization Bearer scheme invalid
+	a.srv.parseToken(reqAuthBearerInvalidScheme, &token)
+	if token != "agent" {
+		t.Fatalf("bad: %s", token)
+	}
+
+	// Check if Authorization Bearer token is empty
+	a.srv.parseToken(reqAuthBearerTokenEmpty, &token)
+	if token != "agent" {
+		t.Fatalf("bad: %s", token)
+	}
+
+	// Check if the Authorization Bearer token is invalid
+	a.srv.parseToken(reqAuthBearerTokenInvalid, &token)
+	if token != "agent" {
+		t.Fatalf("bad: %s", token)
+	}
+
+	// Check multi spaces between Authorization Bearer and token value
+	a.srv.parseToken(reqAuthBearerTokenMultiSpaces, &token)
+	if token != "bearer-token" {
+		t.Fatalf("bad: %s", token)
+	}
+
+	// Check if Authorization Bearer token with spaces is parsed correctly
+	a.srv.parseToken(reqAuthBearerTokenSpaces, &token)
+	if token != "bearer-token" {
+		t.Fatalf("bad: %s", token)
+	}
+
+	// Check if explicit token has precedence over Authorization bearer token
+	a.srv.parseToken(reqAuthBearerAndQsToken, &token)
+	if token != "qstoken" {
+		t.Fatalf("bad: %s", token)
+	}
+
+	// Check if X-Consul-Token has precedence over Authorization bearer token
+	a.srv.parseToken(reqAuthBearerAndXToken, &token)
+	if token != "xtoken" {
+		t.Fatalf("bad: %s", token)
+	}
 }
 
 func TestEnableWebUI(t *testing.T) {

website/source/api/index.html.md

@@ -21,9 +21,10 @@ All API routes are prefixed with `/v1/`. This documentation is only for the v1 A
 Several endpoints in Consul use or require ACL tokens to operate. An agent
 can be configured to use a default token in requests using the `acl_token`
 configuration option. However, the token can also be specified per-request
-by using the `X-Consul-Token` request header or the `token` query string
+by using the `X-Consul-Token` request header or Bearer header in Authorization
-parameter. The request header takes precedence over the default token, and
+header or the `token` query string parameter. The request header takes
-the query string parameter takes precedence over everything.
+precedence over the default token, and the query string parameter takes
+precedence over everything.
 
 For more details about ACLs, please see the [ACL Guide](/docs/guides/acl.html).
 

website/source/docs/guides/acl.html.md

@@ -32,7 +32,8 @@ The type is either "client" (meaning the token cannot modify ACL rules) or "mana
 
 The token ID is passed along with each RPC request to the servers. Consul's
 [HTTP endpoints](/api/index.html) can accept tokens via the `token`
-query string parameter, or the `X-Consul-Token` request header. Consul's
+query string parameter, or the `X-Consul-Token` request header, or Authorization Bearer
+token [RFC6750](https://tools.ietf.org/html/rfc6750). Consul's
 [CLI commands](/docs/commands/index.html) can accept tokens via the
 `token` argument, or the `CONSUL_HTTP_TOKEN` environment variable.
 
@@ -612,9 +613,9 @@ On success, the token ID is returned:
 ```
 
 This token ID can then be passed into Consul's HTTP APIs via the `token`
-query string parameter, or the `X-Consul-Token` request header, or Consul's
+query string parameter, or the `X-Consul-Token` request header, or Authorization
-CLI commands via the `token` argument, or the `CONSUL_HTTP_TOKEN` environment
+Bearer token header, or Consul's CLI commands via the `token` argument,
-variable.
+or the `CONSUL_HTTP_TOKEN` environment variable.
 
 #### Agent Rules