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dex/examples/example-app/main.go
Eng Zer Jun f0186ff265
refactor: move from io/ioutil to io and os package
The io/ioutil package has been deprecated as of Go 1.16, see
https://golang.org/doc/go1.16#ioutil. This commit replaces the existing
io/ioutil functions with their new definitions in io and os packages.

Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>
2021-09-17 14:12:39 +08:00

340 lines
9.5 KiB
Go

package main
import (
"bytes"
"context"
"crypto/tls"
"crypto/x509"
"encoding/json"
"errors"
"fmt"
"log"
"net"
"net/http"
"net/http/httputil"
"net/url"
"os"
"strings"
"time"
"github.com/coreos/go-oidc/v3/oidc"
"github.com/spf13/cobra"
"golang.org/x/oauth2"
)
const exampleAppState = "I wish to wash my irish wristwatch"
type app struct {
clientID string
clientSecret string
redirectURI string
verifier *oidc.IDTokenVerifier
provider *oidc.Provider
// Does the provider use "offline_access" scope to request a refresh token
// or does it use "access_type=offline" (e.g. Google)?
offlineAsScope bool
client *http.Client
}
// return an HTTP client which trusts the provided root CAs.
func httpClientForRootCAs(rootCAs string) (*http.Client, error) {
tlsConfig := tls.Config{RootCAs: x509.NewCertPool()}
rootCABytes, err := os.ReadFile(rootCAs)
if err != nil {
return nil, fmt.Errorf("failed to read root-ca: %v", err)
}
if !tlsConfig.RootCAs.AppendCertsFromPEM(rootCABytes) {
return nil, fmt.Errorf("no certs found in root CA file %q", rootCAs)
}
return &http.Client{
Transport: &http.Transport{
TLSClientConfig: &tlsConfig,
Proxy: http.ProxyFromEnvironment,
Dial: (&net.Dialer{
Timeout: 30 * time.Second,
KeepAlive: 30 * time.Second,
}).Dial,
TLSHandshakeTimeout: 10 * time.Second,
ExpectContinueTimeout: 1 * time.Second,
},
}, nil
}
type debugTransport struct {
t http.RoundTripper
}
func (d debugTransport) RoundTrip(req *http.Request) (*http.Response, error) {
reqDump, err := httputil.DumpRequest(req, true)
if err != nil {
return nil, err
}
log.Printf("%s", reqDump)
resp, err := d.t.RoundTrip(req)
if err != nil {
return nil, err
}
respDump, err := httputil.DumpResponse(resp, true)
if err != nil {
resp.Body.Close()
return nil, err
}
log.Printf("%s", respDump)
return resp, nil
}
func cmd() *cobra.Command {
var (
a app
issuerURL string
listen string
tlsCert string
tlsKey string
rootCAs string
debug bool
)
c := cobra.Command{
Use: "example-app",
Short: "An example OpenID Connect client",
Long: "",
RunE: func(cmd *cobra.Command, args []string) error {
if len(args) != 0 {
return errors.New("surplus arguments provided")
}
u, err := url.Parse(a.redirectURI)
if err != nil {
return fmt.Errorf("parse redirect-uri: %v", err)
}
listenURL, err := url.Parse(listen)
if err != nil {
return fmt.Errorf("parse listen address: %v", err)
}
if rootCAs != "" {
client, err := httpClientForRootCAs(rootCAs)
if err != nil {
return err
}
a.client = client
}
if debug {
if a.client == nil {
a.client = &http.Client{
Transport: debugTransport{http.DefaultTransport},
}
} else {
a.client.Transport = debugTransport{a.client.Transport}
}
}
if a.client == nil {
a.client = http.DefaultClient
}
// TODO(ericchiang): Retry with backoff
ctx := oidc.ClientContext(context.Background(), a.client)
provider, err := oidc.NewProvider(ctx, issuerURL)
if err != nil {
return fmt.Errorf("failed to query provider %q: %v", issuerURL, err)
}
var s struct {
// What scopes does a provider support?
//
// See: https://openid.net/specs/openid-connect-discovery-1_0.html#ProviderMetadata
ScopesSupported []string `json:"scopes_supported"`
}
if err := provider.Claims(&s); err != nil {
return fmt.Errorf("failed to parse provider scopes_supported: %v", err)
}
if len(s.ScopesSupported) == 0 {
// scopes_supported is a "RECOMMENDED" discovery claim, not a required
// one. If missing, assume that the provider follows the spec and has
// an "offline_access" scope.
a.offlineAsScope = true
} else {
// See if scopes_supported has the "offline_access" scope.
a.offlineAsScope = func() bool {
for _, scope := range s.ScopesSupported {
if scope == oidc.ScopeOfflineAccess {
return true
}
}
return false
}()
}
a.provider = provider
a.verifier = provider.Verifier(&oidc.Config{ClientID: a.clientID})
http.HandleFunc("/", a.handleIndex)
http.HandleFunc("/login", a.handleLogin)
http.HandleFunc(u.Path, a.handleCallback)
switch listenURL.Scheme {
case "http":
log.Printf("listening on %s", listen)
return http.ListenAndServe(listenURL.Host, nil)
case "https":
log.Printf("listening on %s", listen)
return http.ListenAndServeTLS(listenURL.Host, tlsCert, tlsKey, nil)
default:
return fmt.Errorf("listen address %q is not using http or https", listen)
}
},
}
c.Flags().StringVar(&a.clientID, "client-id", "example-app", "OAuth2 client ID of this application.")
c.Flags().StringVar(&a.clientSecret, "client-secret", "ZXhhbXBsZS1hcHAtc2VjcmV0", "OAuth2 client secret of this application.")
c.Flags().StringVar(&a.redirectURI, "redirect-uri", "http://127.0.0.1:5555/callback", "Callback URL for OAuth2 responses.")
c.Flags().StringVar(&issuerURL, "issuer", "http://127.0.0.1:5556/dex", "URL of the OpenID Connect issuer.")
c.Flags().StringVar(&listen, "listen", "http://127.0.0.1:5555", "HTTP(S) address to listen at.")
c.Flags().StringVar(&tlsCert, "tls-cert", "", "X509 cert file to present when serving HTTPS.")
c.Flags().StringVar(&tlsKey, "tls-key", "", "Private key for the HTTPS cert.")
c.Flags().StringVar(&rootCAs, "issuer-root-ca", "", "Root certificate authorities for the issuer. Defaults to host certs.")
c.Flags().BoolVar(&debug, "debug", false, "Print all request and responses from the OpenID Connect issuer.")
return &c
}
func main() {
if err := cmd().Execute(); err != nil {
fmt.Fprintf(os.Stderr, "error: %v\n", err)
os.Exit(2)
}
}
func (a *app) handleIndex(w http.ResponseWriter, r *http.Request) {
renderIndex(w)
}
func (a *app) oauth2Config(scopes []string) *oauth2.Config {
return &oauth2.Config{
ClientID: a.clientID,
ClientSecret: a.clientSecret,
Endpoint: a.provider.Endpoint(),
Scopes: scopes,
RedirectURL: a.redirectURI,
}
}
func (a *app) handleLogin(w http.ResponseWriter, r *http.Request) {
var scopes []string
if extraScopes := r.FormValue("extra_scopes"); extraScopes != "" {
scopes = strings.Split(extraScopes, " ")
}
var clients []string
if crossClients := r.FormValue("cross_client"); crossClients != "" {
clients = strings.Split(crossClients, " ")
}
for _, client := range clients {
scopes = append(scopes, "audience:server:client_id:"+client)
}
connectorID := ""
if id := r.FormValue("connector_id"); id != "" {
connectorID = id
}
authCodeURL := ""
scopes = append(scopes, "openid", "profile", "email")
if r.FormValue("offline_access") != "yes" {
authCodeURL = a.oauth2Config(scopes).AuthCodeURL(exampleAppState)
} else if a.offlineAsScope {
scopes = append(scopes, "offline_access")
authCodeURL = a.oauth2Config(scopes).AuthCodeURL(exampleAppState)
} else {
authCodeURL = a.oauth2Config(scopes).AuthCodeURL(exampleAppState, oauth2.AccessTypeOffline)
}
if connectorID != "" {
authCodeURL = authCodeURL + "&connector_id=" + connectorID
}
http.Redirect(w, r, authCodeURL, http.StatusSeeOther)
}
func (a *app) handleCallback(w http.ResponseWriter, r *http.Request) {
var (
err error
token *oauth2.Token
)
ctx := oidc.ClientContext(r.Context(), a.client)
oauth2Config := a.oauth2Config(nil)
switch r.Method {
case http.MethodGet:
// Authorization redirect callback from OAuth2 auth flow.
if errMsg := r.FormValue("error"); errMsg != "" {
http.Error(w, errMsg+": "+r.FormValue("error_description"), http.StatusBadRequest)
return
}
code := r.FormValue("code")
if code == "" {
http.Error(w, fmt.Sprintf("no code in request: %q", r.Form), http.StatusBadRequest)
return
}
if state := r.FormValue("state"); state != exampleAppState {
http.Error(w, fmt.Sprintf("expected state %q got %q", exampleAppState, state), http.StatusBadRequest)
return
}
token, err = oauth2Config.Exchange(ctx, code)
case http.MethodPost:
// Form request from frontend to refresh a token.
refresh := r.FormValue("refresh_token")
if refresh == "" {
http.Error(w, fmt.Sprintf("no refresh_token in request: %q", r.Form), http.StatusBadRequest)
return
}
t := &oauth2.Token{
RefreshToken: refresh,
Expiry: time.Now().Add(-time.Hour),
}
token, err = oauth2Config.TokenSource(ctx, t).Token()
default:
http.Error(w, fmt.Sprintf("method not implemented: %s", r.Method), http.StatusBadRequest)
return
}
if err != nil {
http.Error(w, fmt.Sprintf("failed to get token: %v", err), http.StatusInternalServerError)
return
}
rawIDToken, ok := token.Extra("id_token").(string)
if !ok {
http.Error(w, "no id_token in token response", http.StatusInternalServerError)
return
}
idToken, err := a.verifier.Verify(r.Context(), rawIDToken)
if err != nil {
http.Error(w, fmt.Sprintf("failed to verify ID token: %v", err), http.StatusInternalServerError)
return
}
accessToken, ok := token.Extra("access_token").(string)
if !ok {
http.Error(w, "no access_token in token response", http.StatusInternalServerError)
return
}
var claims json.RawMessage
if err := idToken.Claims(&claims); err != nil {
http.Error(w, fmt.Sprintf("error decoding ID token claims: %v", err), http.StatusInternalServerError)
return
}
buff := new(bytes.Buffer)
if err := json.Indent(buff, []byte(claims), "", " "); err != nil {
http.Error(w, fmt.Sprintf("error indenting ID token claims: %v", err), http.StatusInternalServerError)
return
}
renderToken(w, a.redirectURI, rawIDToken, accessToken, token.RefreshToken, buff.String())
}