mirror of
https://github.com/gravitational/teleport.git
synced 2026-11-04 02:03:53 +08:00
Andrew Burke
e3a8fb7a0f
This change updates NO_PROXY handling to allow blocking specific host:port combinations, rather than just the host. It also adds a special case for downgrading requests to plain HTTP when --insecure is true and the request goes through a plain HTTP proxy at localhost (i.e. HTTP_PROXY=http://localhost).
103 lines
2.9 KiB
Go
103 lines
2.9 KiB
Go
/*
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Copyright 2022 Gravitational, Inc.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package proxy
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import (
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"net/http"
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"net/url"
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"strings"
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"github.com/gravitational/trace"
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"golang.org/x/net/http/httpproxy"
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)
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// GetProxyAddress gets the HTTP proxy address to use for a given address, if any.
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func GetProxyAddress(dialAddr string) *url.URL {
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addrURL, err := parse(dialAddr)
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if err != nil || addrURL == nil {
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return nil
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}
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proxyFunc := httpproxy.FromEnvironment().ProxyFunc()
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if addrURL.Scheme != "" {
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proxyURL, err := proxyFunc(addrURL)
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if err != nil {
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return nil
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}
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return proxyURL
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}
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for _, scheme := range []string{"https", "http"} {
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addrURL.Scheme = scheme
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proxyURL, err := proxyFunc(addrURL)
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if err == nil && proxyURL != nil {
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return proxyURL
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}
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}
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return nil
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}
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// parse parses an absolute URL. Unlike url.Parse, absolute URLs without a scheme are allowed.
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func parse(addr string) (*url.URL, error) {
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if addr == "" {
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return nil, nil
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}
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addrURL, err := url.Parse(addr)
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if err == nil && addrURL.Host != "" {
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return addrURL, nil
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}
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// url.Parse won't correctly parse an absolute URL without a scheme, so try again with a scheme.
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addrURL, err2 := url.Parse("http://" + addr)
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if err2 != nil {
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return nil, trace.NewAggregate(err, err2)
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}
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addrURL.Scheme = ""
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return addrURL, nil
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}
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// HTTPFallbackRoundTripper is a wrapper for http.Transport that downgrades requests
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// to plain HTTP when using a plain HTTP proxy at localhost.
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type HTTPFallbackRoundTripper struct {
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*http.Transport
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isProxyHTTPLocalhost bool
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}
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// NewHTTPFallbackRoundTripper creates a new initialized HTTP fallback roundtripper.
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func NewHTTPFallbackRoundTripper(transport *http.Transport, insecure bool) *HTTPFallbackRoundTripper {
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proxyConfig := httpproxy.FromEnvironment()
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rt := HTTPFallbackRoundTripper{
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Transport: transport,
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isProxyHTTPLocalhost: strings.HasPrefix(proxyConfig.HTTPProxy, "http://localhost"),
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}
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if rt.TLSClientConfig != nil {
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rt.TLSClientConfig.InsecureSkipVerify = insecure
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}
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return &rt
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}
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// RoundTrip executes a single HTTP transaction. Part of the RoundTripper interface.
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func (rt *HTTPFallbackRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
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tlsConfig := rt.Transport.TLSClientConfig
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// Use plain HTTP if proxying via http://localhost in insecure mode.
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if rt.isProxyHTTPLocalhost && tlsConfig != nil && tlsConfig.InsecureSkipVerify {
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req.URL.Scheme = "http"
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}
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return rt.Transport.RoundTrip(req)
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}
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