/
middleware.go
200 lines (177 loc) · 6.05 KB
/
middleware.go
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package http
import (
"context"
"encoding/base64"
"fmt"
"net/http"
"strings"
"sync"
goauth "github.com/abbot/go-http-auth"
"github.com/rclone/rclone/fs"
)
// parseAuthorization parses the Authorization header into user, pass
// it returns a boolean as to whether the parse was successful
func parseAuthorization(r *http.Request) (user, pass string, ok bool) {
authHeader := r.Header.Get("Authorization")
if authHeader != "" {
s := strings.SplitN(authHeader, " ", 2)
if len(s) == 2 && s[0] == "Basic" {
b, err := base64.StdEncoding.DecodeString(s[1])
if err == nil {
parts := strings.SplitN(string(b), ":", 2)
user = parts[0]
if len(parts) > 1 {
pass = parts[1]
ok = true
}
}
}
}
return
}
// LoggedBasicAuth simply wraps the goauth.BasicAuth struct
type LoggedBasicAuth struct {
goauth.BasicAuth
}
// CheckAuth extends BasicAuth.CheckAuth to emit a log entry for unauthorised requests
func (a *LoggedBasicAuth) CheckAuth(r *http.Request) string {
username := a.BasicAuth.CheckAuth(r)
if username == "" {
user, _, _ := parseAuthorization(r)
fs.Infof(r.URL.Path, "%s: Unauthorized request from %s", r.RemoteAddr, user)
}
return username
}
// NewLoggedBasicAuthenticator instantiates a new instance of LoggedBasicAuthenticator
func NewLoggedBasicAuthenticator(realm string, secrets goauth.SecretProvider) *LoggedBasicAuth {
return &LoggedBasicAuth{BasicAuth: goauth.BasicAuth{Realm: realm, Secrets: secrets}}
}
// Helper to generate required interface for middleware
func basicAuth(authenticator *LoggedBasicAuth) func(next http.Handler) http.Handler {
return func(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
// skip auth for unix socket
if IsUnixSocket(r) {
next.ServeHTTP(w, r)
return
}
// skip auth for CORS preflight
if r.Method == "OPTIONS" {
next.ServeHTTP(w, r)
return
}
username := authenticator.CheckAuth(r)
if username == "" {
authenticator.RequireAuth(w, r)
return
}
ctx := context.WithValue(r.Context(), ctxKeyUser, username)
next.ServeHTTP(w, r.WithContext(ctx))
})
}
}
// MiddlewareAuthCertificateUser instantiates middleware that extracts the authenticated user via client certificate common name
func MiddlewareAuthCertificateUser() Middleware {
return func(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
for _, cert := range r.TLS.PeerCertificates {
if cert.Subject.CommonName != "" {
r = r.WithContext(context.WithValue(r.Context(), ctxKeyUser, cert.Subject.CommonName))
next.ServeHTTP(w, r)
return
}
}
code := http.StatusUnauthorized
w.Header().Set("Content-Type", "text/plain")
http.Error(w, http.StatusText(code), code)
})
}
}
// MiddlewareAuthHtpasswd instantiates middleware that authenticates against the passed htpasswd file
func MiddlewareAuthHtpasswd(path, realm string) Middleware {
fs.Infof(nil, "Using %q as htpasswd storage", path)
secretProvider := goauth.HtpasswdFileProvider(path)
authenticator := NewLoggedBasicAuthenticator(realm, secretProvider)
return basicAuth(authenticator)
}
// MiddlewareAuthBasic instantiates middleware that authenticates for a single user
func MiddlewareAuthBasic(user, pass, realm, salt string) Middleware {
fs.Infof(nil, "Using --user %s --pass XXXX as authenticated user", user)
pass = string(goauth.MD5Crypt([]byte(pass), []byte(salt), []byte("$1$")))
secretProvider := func(u, r string) string {
if user == u {
return pass
}
return ""
}
authenticator := NewLoggedBasicAuthenticator(realm, secretProvider)
return basicAuth(authenticator)
}
// MiddlewareAuthCustom instantiates middleware that authenticates using a custom function
func MiddlewareAuthCustom(fn CustomAuthFn, realm string, userFromContext bool) Middleware {
return func(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
// skip auth for unix socket
if IsUnixSocket(r) {
next.ServeHTTP(w, r)
return
}
// skip auth for CORS preflight
if r.Method == "OPTIONS" {
next.ServeHTTP(w, r)
return
}
user, pass, ok := parseAuthorization(r)
if !ok && userFromContext {
user, ok = CtxGetUser(r.Context())
}
if !ok {
code := http.StatusUnauthorized
w.Header().Set("Content-Type", "text/plain")
w.Header().Set("WWW-Authenticate", fmt.Sprintf(`Basic realm=%q, charset="UTF-8"`, realm))
http.Error(w, http.StatusText(code), code)
return
}
value, err := fn(user, pass)
if err != nil {
fs.Infof(r.URL.Path, "%s: Auth failed from %s: %v", r.RemoteAddr, user, err)
goauth.NewBasicAuthenticator(realm, func(user, realm string) string { return "" }).RequireAuth(w, r) //Reuse BasicAuth error reporting
return
}
if value != nil {
r = r.WithContext(context.WithValue(r.Context(), ctxKeyAuth, value))
}
next.ServeHTTP(w, r)
})
}
}
var onlyOnceWarningAllowOrigin sync.Once
// MiddlewareCORS instantiates middleware that handles basic CORS protections for rcd
func MiddlewareCORS(allowOrigin string) Middleware {
onlyOnceWarningAllowOrigin.Do(func() {
if allowOrigin == "*" {
fs.Logf(nil, "Warning: Allow origin set to *. This can cause serious security problems.")
}
})
return func(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
// skip cors for unix sockets
if IsUnixSocket(r) {
next.ServeHTTP(w, r)
return
}
if allowOrigin != "" {
w.Header().Add("Access-Control-Allow-Origin", allowOrigin)
w.Header().Add("Access-Control-Allow-Headers", "authorization, Content-Type")
w.Header().Add("Access-Control-Allow-Methods", "COPY, DELETE, GET, HEAD, LOCK, MKCOL, MOVE, OPTIONS, POST, PROPFIND, PROPPATCH, PUT, TRACE, UNLOCK")
}
next.ServeHTTP(w, r)
})
}
}
// MiddlewareStripPrefix instantiates middleware that removes the BaseURL from the path
func MiddlewareStripPrefix(prefix string) Middleware {
return func(next http.Handler) http.Handler {
return http.StripPrefix(prefix, next)
}
}