/
auth.go
226 lines (193 loc) · 5.46 KB
/
auth.go
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package main
import (
"bufio"
"encoding/base64"
"encoding/json"
"fmt"
"log"
"net/http"
"net/url"
"os"
"os/exec"
"strconv"
"strings"
)
// HTTP proxy authentication.
func (c *config) readPasswordFile(filename string) error {
f, err := os.Open(filename)
if err != nil {
return fmt.Errorf("could not open %s: %s", filename, err)
}
defer f.Close()
cr := newConfigReader(f)
for {
line, err := cr.ReadLine()
if err != nil {
break
}
words := strings.Fields(line)
switch len(words) {
case 2:
c.Passwords[words[0]] = words[1]
case 3:
user, pass, portStr := words[0], words[1], words[2]
c.Passwords[user] = pass
port, err := strconv.Atoi(portStr)
if err != nil {
log.Printf("invalid port number %q in password file line: %s", portStr, line)
continue
}
c.CustomPorts[user] = customPortInfo{
Port: port,
}
c.UserForPort[port] = user
case 4:
user, pass, portStr, clientPlatform := words[0], words[1], words[2], words[3]
c.Passwords[user] = pass
port, err := strconv.Atoi(portStr)
if err != nil {
log.Printf("invalid port number %q in password file line: %s", portStr, line)
continue
}
c.CustomPorts[user] = customPortInfo{
Port: port,
ClientPlatform: clientPlatform,
}
c.UserForPort[port] = user
case 5:
user, pass, portStr, clientPlatform, networks := words[0], words[1], words[2], words[3], words[4]
c.Passwords[user] = pass
port, err := strconv.Atoi(portStr)
if err != nil {
log.Printf("invalid port number %q in password file line: %s", portStr, line)
continue
}
c.CustomPorts[user] = customPortInfo{
Port: port,
ClientPlatform: clientPlatform,
ExpectedNetworks: strings.Split(networks, ","),
}
c.UserForPort[port] = user
default:
log.Println("malformed line in password file:", line)
}
}
return nil
}
func send407(w http.ResponseWriter) {
c := getConfig()
w.Header().Set("Proxy-Authenticate", "Basic realm="+c.AuthRealm)
http.Error(w, "Proxy authentication required", http.StatusProxyAuthRequired)
}
// ProxyCredentials returns the username and password from r's
// Proxy-Authorization header.
func ProxyCredentials(r *http.Request) (user, pass string, ok bool) {
auth := r.Header.Get("Proxy-Authorization")
if auth == "" || !strings.HasPrefix(auth, "Basic ") {
return "", "", false
}
return decodeBase64Credentials(strings.TrimPrefix(auth, "Basic "))
}
// decodeBase64Credentials decodes a base64-encoded username:password pair
// such as those used in HTTP basic authentication.
func decodeBase64Credentials(auth string) (user, pass string, ok bool) {
auth = strings.TrimSpace(auth)
enc := base64.StdEncoding
buf := make([]byte, enc.DecodedLen(len(auth)))
n, err := enc.Decode(buf, []byte(auth))
if err != nil {
return "", "", false
}
auth = string(buf[:n])
colon := strings.Index(auth, ":")
if colon == -1 {
return "", "", false
}
return auth[:colon], auth[colon+1:], true
}
// ValidCredentials returns whether user and password are a valid combination.
func (conf *config) ValidCredentials(user, password string) bool {
conf.PasswordLock.RLock()
ok := password == conf.Passwords[user] && password != ""
conf.PasswordLock.RUnlock()
if ok {
return true
}
for _, a := range conf.Authenticators {
if a(user, password) {
if _, ok := conf.Passwords[user]; !ok {
// Cache the password for later use.
conf.PasswordLock.Lock()
conf.Passwords[user] = password
conf.PasswordLock.Unlock()
}
return true
}
}
return false
}
func (conf *config) addAuthenticator(path string) error {
conf.Authenticators = append(conf.Authenticators, func(user, password string) bool {
cmd := exec.Command(path, user, password)
err := cmd.Run()
return err == nil
})
return nil
}
func (conf *config) addHTTPAuthenticator(endpoint string) error {
var client http.Client
client.Transport = transportWithExtraRootCerts
conf.Authenticators = append(conf.Authenticators, func(user, password string) bool {
formData := make(url.Values)
formData.Set("username", user)
formData.Set("password", password)
resp, err := client.Post(endpoint, "application/x-www-form-urlencoded", strings.NewReader(formData.Encode()))
if err != nil {
log.Printf("Error communicating with authentication API endpoint %s: %v", endpoint, err)
return false
}
defer resp.Body.Close()
if resp.StatusCode != 200 {
return false
}
var userInfo struct {
DeviceGroups []string `json:"device_groups"`
}
if err := json.NewDecoder(resp.Body).Decode(&userInfo); err == nil {
conf.ACLs.ExternalDGLock.Lock()
if conf.ACLs.ExternalDeviceGroups == nil {
conf.ACLs.ExternalDeviceGroups = map[string][]string{}
}
conf.ACLs.ExternalDeviceGroups[user] = userInfo.DeviceGroups
conf.ACLs.ExternalDGLock.Unlock()
} else {
log.Printf("Error decoding authenticator-api response for %s: %v", user, err)
}
return true
})
return nil
}
func (c *config) loadIPToUser(filename string) error {
f, err := os.Open(filename)
if err != nil {
return fmt.Errorf("could not open %s: %s\n", filename, err)
}
defer f.Close()
s := bufio.NewScanner(f)
for s.Scan() {
line := strings.TrimSpace(s.Text())
if line == "" || line[0] == '#' {
continue
}
fields := strings.Fields(line)
if len(fields) > 2 && strings.HasPrefix(fields[2], "#") {
fields = fields[:2]
}
if len(fields) != 2 {
log.Printf("Syntax error in %s: %q", filename, line)
continue
}
c.IPToUser[fields[0]] = fields[1]
}
return s.Err()
}