zrok/endpoints/publicProxy/http.go
2023-12-15 12:15:40 -05:00

382 lines
13 KiB
Go

package publicProxy
import (
"context"
"crypto/md5"
"fmt"
"github.com/golang-jwt/jwt/v5"
"github.com/openziti/sdk-golang/ziti"
"github.com/openziti/zrok/endpoints"
"github.com/openziti/zrok/endpoints/publicProxy/healthUi"
"github.com/openziti/zrok/endpoints/publicProxy/notFoundUi"
"github.com/openziti/zrok/endpoints/publicProxy/unauthorizedUi"
"github.com/openziti/zrok/environment"
"github.com/openziti/zrok/sdk/golang/sdk"
"github.com/openziti/zrok/util"
"github.com/pkg/errors"
"github.com/sirupsen/logrus"
"net"
"net/http"
"net/http/httputil"
"net/url"
"strings"
"time"
)
type HttpFrontend struct {
cfg *Config
zCtx ziti.Context
handler http.Handler
}
func NewHTTP(cfg *Config) (*HttpFrontend, error) {
var key []byte
if cfg.Oauth != nil {
hash := md5.New()
n, err := hash.Write([]byte(cfg.Oauth.HashKey))
if err != nil {
return nil, err
}
if n != len(cfg.Oauth.HashKey) {
return nil, errors.New("short hash")
}
key = hash.Sum(nil)
}
root, err := environment.LoadRoot()
if err != nil {
return nil, errors.Wrap(err, "error loading environment root")
}
zCfgPath, err := root.ZitiIdentityNamed(cfg.Identity)
if err != nil {
return nil, errors.Wrapf(err, "error getting ziti identity '%v' from environment", cfg.Identity)
}
zCfg, err := ziti.NewConfigFromFile(zCfgPath)
if err != nil {
return nil, errors.Wrap(err, "error loading config")
}
zCfg.ConfigTypes = []string{sdk.ZrokProxyConfig}
zCtx, err := ziti.NewContext(zCfg)
if err != nil {
return nil, errors.Wrap(err, "error loading ziti context")
}
zDialCtx := zitiDialContext{ctx: zCtx}
zTransport := http.DefaultTransport.(*http.Transport).Clone()
zTransport.DialContext = zDialCtx.Dial
proxy, err := newServiceProxy(cfg, zCtx)
if err != nil {
return nil, err
}
proxy.Transport = zTransport
if err := configureOauthHandlers(context.Background(), cfg, false); err != nil {
return nil, err
}
handler := authHandler(util.NewProxyHandler(proxy), cfg, key, zCtx)
return &HttpFrontend{
cfg: cfg,
zCtx: zCtx,
handler: handler,
}, nil
}
func (f *HttpFrontend) Run() error {
return http.ListenAndServe(f.cfg.Address, f.handler)
}
type zitiDialContext struct {
ctx ziti.Context
}
func (c *zitiDialContext) Dial(_ context.Context, _ string, addr string) (net.Conn, error) {
shrToken := strings.Split(addr, ":")[0] // ignore :port (we get passed 'host:port')
conn, err := c.ctx.Dial(shrToken)
if err != nil {
return conn, err
}
return conn, nil
}
func newServiceProxy(cfg *Config, ctx ziti.Context) (*httputil.ReverseProxy, error) {
proxy := hostTargetReverseProxy(cfg, ctx)
director := proxy.Director
proxy.Director = func(req *http.Request) {
director(req)
req.Header.Set("X-Proxy", "zrok")
}
proxy.ModifyResponse = func(resp *http.Response) error {
return nil
}
proxy.ErrorHandler = func(w http.ResponseWriter, r *http.Request, err error) {
logrus.Errorf("error proxying: %v", err)
notFoundUi.WriteNotFound(w)
}
return proxy, nil
}
func hostTargetReverseProxy(cfg *Config, ctx ziti.Context) *httputil.ReverseProxy {
director := func(req *http.Request) {
targetShrToken := resolveService(cfg.HostMatch, req.Host)
if svc, found := endpoints.GetRefreshedService(targetShrToken, ctx); found {
if cfg, found := svc.Config[sdk.ZrokProxyConfig]; found {
logrus.Debugf("auth model: %v", cfg)
} else {
logrus.Warn("no config!")
}
if target, err := url.Parse(fmt.Sprintf("http://%v", targetShrToken)); err == nil {
logrus.Infof("[%v] -> %v", targetShrToken, req.URL)
targetQuery := target.RawQuery
req.URL.Scheme = target.Scheme
req.URL.Host = target.Host
req.URL.Path, req.URL.RawPath = endpoints.JoinURLPath(target, req.URL)
if targetQuery == "" || req.URL.RawQuery == "" {
req.URL.RawQuery = targetQuery + req.URL.RawQuery
} else {
req.URL.RawQuery = targetQuery + "&" + req.URL.RawQuery
}
if _, ok := req.Header["User-Agent"]; !ok {
// explicitly disable User-Agent so it's not set to default value
req.Header.Set("User-Agent", "")
}
} else {
logrus.Errorf("error proxying: %v", err)
}
}
}
return &httputil.ReverseProxy{Director: director}
}
func authHandler(handler http.Handler, pcfg *Config, key []byte, ctx ziti.Context) http.HandlerFunc {
return func(w http.ResponseWriter, r *http.Request) {
shrToken := resolveService(pcfg.HostMatch, r.Host)
if shrToken != "" {
if svc, found := endpoints.GetRefreshedService(shrToken, ctx); found {
if cfg, found := svc.Config[sdk.ZrokProxyConfig]; found {
if scheme, found := cfg["auth_scheme"]; found {
switch scheme {
case string(sdk.None):
logrus.Debugf("auth scheme none '%v'", shrToken)
handler.ServeHTTP(w, r)
return
case string(sdk.Basic):
logrus.Debugf("auth scheme basic '%v", shrToken)
inUser, inPass, ok := r.BasicAuth()
if !ok {
basicAuthRequired(w, shrToken)
return
}
authed := false
if v, found := cfg["basic_auth"]; found {
if basicAuth, ok := v.(map[string]interface{}); ok {
if v, found := basicAuth["users"]; found {
if arr, ok := v.([]interface{}); ok {
for _, v := range arr {
if um, ok := v.(map[string]interface{}); ok {
username := ""
if v, found := um["username"]; found {
if un, ok := v.(string); ok {
username = un
}
}
password := ""
if v, found := um["password"]; found {
if pw, ok := v.(string); ok {
password = pw
}
}
if username == inUser && password == inPass {
authed = true
break
}
}
}
}
}
}
}
if !authed {
basicAuthRequired(w, shrToken)
return
}
handler.ServeHTTP(w, r)
case string(sdk.Oauth):
logrus.Debugf("auth scheme oauth '%v'", shrToken)
if oauthCfg, found := cfg["oauth"]; found {
if provider, found := oauthCfg.(map[string]interface{})["provider"]; found {
var authCheckInterval time.Duration
if checkInterval, found := oauthCfg.(map[string]interface{})["authorization_check_interval"]; !found {
logrus.Errorf("missing authorization check interval in share config. Defaulting to 3 hours")
authCheckInterval = 3 * time.Hour
} else {
i, err := time.ParseDuration(checkInterval.(string))
if err != nil {
logrus.Errorf("unable to parse authorization check interval in share config (%v). Defaulting to 3 hours", checkInterval)
authCheckInterval = 3 * time.Hour
} else {
authCheckInterval = i
}
}
target := fmt.Sprintf("%s%s", r.Host, r.URL.Path)
cookie, err := r.Cookie("zrok-access")
if err != nil {
logrus.Errorf("unable to get 'zrok-access' cookie: %v", err)
oauthLoginRequired(w, r, pcfg.Oauth, provider.(string), target, authCheckInterval)
return
}
tkn, err := jwt.ParseWithClaims(cookie.Value, &ZrokClaims{}, func(t *jwt.Token) (interface{}, error) {
if pcfg.Oauth == nil {
return nil, fmt.Errorf("missing oauth configuration for access point; unable to parse jwt")
}
return key, nil
})
if err != nil {
logrus.Errorf("unable to parse jwt: %v", err)
oauthLoginRequired(w, r, pcfg.Oauth, provider.(string), target, authCheckInterval)
return
}
claims := tkn.Claims.(*ZrokClaims)
if claims.Provider != provider {
logrus.Error("provider mismatch; restarting auth flow")
oauthLoginRequired(w, r, pcfg.Oauth, provider.(string), target, authCheckInterval)
return
}
if claims.AuthorizationCheckInterval != authCheckInterval {
logrus.Error("authorization check interval mismatch; restarting auth flow")
oauthLoginRequired(w, r, pcfg.Oauth, provider.(string), target, authCheckInterval)
return
}
if claims.Audience != r.Host {
logrus.Errorf("audience claim '%s' does not match requested host '%s'; restarting auth flow", claims.Audience, r.Host)
oauthLoginRequired(w, r, pcfg.Oauth, provider.(string), target, authCheckInterval)
return
}
if validDomains, found := oauthCfg.(map[string]interface{})["email_domains"]; found {
if castedDomains, ok := validDomains.([]interface{}); !ok {
logrus.Error("invalid email domain format")
return
} else {
if len(castedDomains) > 0 {
found := false
for _, domain := range castedDomains {
if strings.HasSuffix(claims.Email, domain.(string)) {
found = true
break
}
}
if !found {
logrus.Warnf("invalid email domain")
unauthorizedUi.WriteUnauthorized(w)
return
}
}
}
}
handler.ServeHTTP(w, r)
return
} else {
logrus.Warnf("%v -> no provider for '%v'", r.RemoteAddr, provider)
notFoundUi.WriteNotFound(w)
}
} else {
logrus.Warnf("%v -> no oauth cfg for '%v'", r.RemoteAddr, shrToken)
notFoundUi.WriteNotFound(w)
}
default:
logrus.Infof("invalid auth scheme '%v'", scheme)
basicAuthRequired(w, shrToken)
return
}
} else {
logrus.Warnf("%v -> no auth scheme for '%v'", r.RemoteAddr, shrToken)
notFoundUi.WriteNotFound(w)
}
} else {
logrus.Warnf("%v -> no proxy config for '%v'", r.RemoteAddr, shrToken)
notFoundUi.WriteNotFound(w)
}
} else {
logrus.Warnf("%v -> service '%v' not found", r.RemoteAddr, shrToken)
notFoundUi.WriteNotFound(w)
}
} else {
logrus.Debugf("host '%v' did not match host match, returning health check", r.Host)
healthUi.WriteHealthOk(w)
}
}
}
type ZrokClaims struct {
Email string `json:"email"`
AccessToken string `json:"accessToken"`
Provider string `json:"provider"`
Audience string `json:"aud"`
AuthorizationCheckInterval time.Duration `json:"authorizationCheckInterval"`
jwt.RegisteredClaims
}
func SetZrokCookie(w http.ResponseWriter, cookieDomain, email, accessToken, provider string, checkInterval time.Duration, key []byte, targetHost string) {
targetHost = strings.TrimSpace(targetHost)
if targetHost == "" {
logrus.Error("host claim must not be empty")
http.Error(w, "host claim must not be empty", http.StatusBadRequest)
return
}
targetHost = strings.Split(targetHost, "/")[0]
logrus.Debugf("setting zrok-access cookie JWT audience '%s'", targetHost)
tkn := jwt.NewWithClaims(jwt.SigningMethodHS256, ZrokClaims{
Email: email,
AccessToken: accessToken,
Provider: provider,
Audience: targetHost,
AuthorizationCheckInterval: checkInterval,
})
sTkn, err := tkn.SignedString(key)
if err != nil {
http.Error(w, fmt.Sprintf("after signing cookie token: %v", err.Error()), http.StatusInternalServerError)
return
}
http.SetCookie(w, &http.Cookie{
Name: "zrok-access",
Value: sTkn,
MaxAge: int(checkInterval.Seconds()),
Domain: cookieDomain,
Path: "/",
Expires: time.Now().Add(checkInterval),
// Secure: true, // pending server tls feature https://github.com/openziti/zrok/issues/24
HttpOnly: true, // enabled because zrok frontend is the only intended consumer of this cookie, not client-side scripts
SameSite: http.SameSiteLaxMode, // explicitly set to the default Lax mode which allows the zrok share to be navigated to from another site and receive the cookie
})
}
func basicAuthRequired(w http.ResponseWriter, realm string) {
w.Header().Set("WWW-Authenticate", `Basic realm="`+realm+`"`)
w.WriteHeader(401)
_, _ = w.Write([]byte("No Authorization\n"))
}
func oauthLoginRequired(w http.ResponseWriter, r *http.Request, cfg *OauthConfig, provider, target string, authCheckInterval time.Duration) {
http.Redirect(w, r, fmt.Sprintf("%s/%s/login?targethost=%s&checkInterval=%s", cfg.RedirectUrl, provider, url.QueryEscape(target), authCheckInterval.String()), http.StatusFound)
}
func resolveService(hostMatch string, host string) string {
if hostMatch == "" || strings.Contains(host, hostMatch) {
tokens := strings.Split(host, ".")
if len(tokens) > 0 {
return tokens[0]
}
}
return ""
}