gb vendor fetch github.com/matrix-org/gomatrixserverlib/

vendor/src/github.com/matrix-org/gomatrixserverlib/client.go

@@ -0,0 +1,143 @@
+/* Copyright 2016-2017 Vector Creations Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package gomatrixserverlib
+
+import (
+	"crypto/tls"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net"
+	"net/http"
+	"net/url"
+	"strings"
+)
+
+// A Client makes request to the federation listeners of matrix
+// homeservers
+type Client struct {
+	client http.Client
+}
+
+// UserInfo represents information about a user.
+type UserInfo struct {
+	Sub string `json:"sub"`
+}
+
+// NewClient makes a new Client
+func NewClient() *Client {
+	// TODO: Verify ceritificates
+	tripper := federationTripper{
+		transport: &http.Transport{
+			// Set our own DialTLS function to avoid the default net/http SNI.
+			// By default net/http and crypto/tls set the SNI to the target host.
+			// By avoiding the default implementation we can keep the ServerName
+			// as the empty string so that crypto/tls doesn't add SNI.
+			DialTLS: func(network, addr string) (net.Conn, error) {
+				rawconn, err := net.Dial(network, addr)
+				if err != nil {
+					return nil, err
+				}
+				// Wrap a raw connection ourselves since tls.Dial defaults the SNI
+				conn := tls.Client(rawconn, &tls.Config{
+					ServerName: "",
+					// TODO: We should be checking that the TLS certificate we see here matches
+					//       one of the allowed SHA-256 fingerprints for the server.
+					InsecureSkipVerify: true,
+				})
+				if err := conn.Handshake(); err != nil {
+					return nil, err
+				}
+				return conn, nil
+			},
+		},
+	}
+
+	return &Client{
+		client: http.Client{Transport: &tripper},
+	}
+}
+
+type federationTripper struct {
+	transport http.RoundTripper
+}
+
+func makeHTTPSURL(u *url.URL, addr string) (httpsURL url.URL) {
+	httpsURL = *u
+	httpsURL.Scheme = "https"
+	httpsURL.Host = addr
+	return
+}
+
+func (f *federationTripper) RoundTrip(r *http.Request) (*http.Response, error) {
+	host := r.URL.Host
+	dnsResult, err := LookupServer(host)
+	if err != nil {
+		return nil, err
+	}
+	var resp *http.Response
+	for _, addr := range dnsResult.Addrs {
+		u := makeHTTPSURL(r.URL, addr)
+		r.URL = &u
+		resp, err = f.transport.RoundTrip(r)
+		if err == nil {
+			return resp, nil
+		}
+	}
+	return nil, fmt.Errorf("no address found for matrix host %v", host)
+}
+
+// LookupUserInfo gets information about a user from a given matrix homeserver
+// using a bearer access token.
+func (fc *Client) LookupUserInfo(matrixServer, token string) (u UserInfo, err error) {
+	url := url.URL{
+		Scheme:   "matrix",
+		Host:     matrixServer,
+		Path:     "/_matrix/federation/v1/openid/userinfo",
+		RawQuery: url.Values{"access_token": []string{token}}.Encode(),
+	}
+
+	var response *http.Response
+	response, err = fc.client.Get(url.String())
+	if response != nil {
+		defer response.Body.Close()
+	}
+	if err != nil {
+		return
+	}
+	if response.StatusCode < 200 || response.StatusCode >= 300 {
+		var errorOutput []byte
+		errorOutput, err = ioutil.ReadAll(response.Body)
+		if err != nil {
+			return
+		}
+		err = fmt.Errorf("HTTP %d : %s", response.StatusCode, errorOutput)
+		return
+	}
+
+	err = json.NewDecoder(response.Body).Decode(&u)
+	if err != nil {
+		return
+	}
+
+	userParts := strings.SplitN(u.Sub, ":", 2)
+	if len(userParts) != 2 || userParts[1] != matrixServer {
+		err = fmt.Errorf("userID doesn't match server name '%v' != '%v'", u.Sub, matrixServer)
+		return
+	}
+
+	return
+}