forked from Psiphon-Labs/psiphon-tunnel-core
/
http_authenticator.go
87 lines (76 loc) · 2.39 KB
/
http_authenticator.go
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/*
* Copyright (c) 2015, Psiphon Inc.
* All rights reserved.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
package upstreamproxy
import (
"fmt"
"net/http"
"strings"
)
type HttpAuthState int
const (
HTTP_AUTH_STATE_UNCHALLENGED HttpAuthState = iota
HTTP_AUTH_STATE_CHALLENGED
HTTP_AUTH_STATE_FAILURE
HTTP_AUTH_STATE_SUCCESS
)
type HttpAuthenticator interface {
PreAuthenticate(req *http.Request) error
Authenticate(req *http.Request, resp *http.Response) error
IsConnectionBased() bool
IsComplete() bool
Reset()
}
func parseAuthChallenge(resp *http.Response) (map[string]string, error) {
challenges := make(map[string]string)
headers := resp.Header[http.CanonicalHeaderKey("proxy-authenticate")]
for _, val := range headers {
s := strings.SplitN(val, " ", 2)
if len(s) == 2 {
challenges[s[0]] = s[1]
}
if len(s) == 1 && s[0] != "" {
challenges[s[0]] = ""
}
}
if len(challenges) == 0 {
return nil, proxyError(fmt.Errorf("No valid challenges in the Proxy-Authenticate header"))
}
return challenges, nil
}
func NewHttpAuthenticator(resp *http.Response, username, password string) (HttpAuthenticator, error) {
challenges, err := parseAuthChallenge(resp)
if err != nil {
//Already wrapped in proxyError
return nil, err
}
// NTLM > Digest > Basic
if _, ok := challenges["NTLM"]; ok {
return newNTLMAuthenticator(username, password), nil
} else if _, ok := challenges["Digest"]; ok {
return newDigestAuthenticator(username, password), nil
} else if _, ok := challenges["Basic"]; ok {
return newBasicAuthenticator(username, password), nil
}
//Unsupported scheme
schemes := make([]string, 0, len(challenges))
for scheme := range challenges {
schemes = append(schemes, scheme)
}
return nil, proxyError(fmt.Errorf("Unsupported proxy authentication scheme in %v", schemes))
}