Commit 467d0273 authored by Eric Chiang's avatar Eric Chiang

*: add example-app

parent 5ce32838
......@@ -21,11 +21,14 @@ else
endif
build: bin/poke
build: bin/poke bin/example-app
bin/poke: FORCE
@go install $(REPO_PATH)/cmd/poke
bin/example-app: FORCE
@go install $(REPO_PATH)/cmd/example-app
test:
@go test $(shell go list ./... | grep -v '/vendor/')
......
package main
import (
"bytes"
"crypto/tls"
"crypto/x509"
"encoding/json"
"errors"
"fmt"
"io/ioutil"
"log"
"net"
"net/http"
"net/url"
"os"
"strings"
"time"
"github.com/ericchiang/oidc"
"github.com/spf13/cobra"
"golang.org/x/net/context"
"golang.org/x/oauth2"
)
type app struct {
clientID string
clientSecret string
redirectURI string
verifier *oidc.IDTokenVerifier
provider *oidc.Provider
ctx context.Context
cancel context.CancelFunc
}
// 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 := ioutil.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
}
func cmd() *cobra.Command {
var (
a app
issuerURL string
listen string
tlsCert string
tlsKey string
rootCAs string
)
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)
}
a.ctx, a.cancel = context.WithCancel(context.Background())
if rootCAs != "" {
client, err := httpClientForRootCAs(rootCAs)
if err != nil {
return err
}
// This sets the OAuth2 client and oidc client.
a.ctx = context.WithValue(a.ctx, oauth2.HTTPClient, &client)
}
// TODO(ericchiang): Retry with backoff
provider, err := oidc.NewProvider(a.ctx, issuerURL)
if err != nil {
return fmt.Errorf("Failed to query provider %q: %v", issuerURL, err)
}
a.provider = provider
a.verifier = provider.NewVerifier(a.ctx, oidc.VerifyAudience(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", "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.")
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)
}
// TODO(ericchiang): Determine if provider does not support "offline_access" or has
// some other mechanism for requesting refresh tokens.
scopes = append(scopes, "openid", "profile", "email", "offline_access")
http.Redirect(w, r, a.oauth2Config(scopes).AuthCodeURL(""), http.StatusSeeOther)
}
func (a *app) handleCallback(w http.ResponseWriter, r *http.Request) {
if errMsg := r.FormValue("error"); errMsg != "" {
http.Error(w, errMsg+": "+r.FormValue("error_description"), http.StatusBadRequest)
return
}
code := r.FormValue("code")
refresh := r.FormValue("refresh_token")
var (
err error
token *oauth2.Token
)
oauth2Config := a.oauth2Config(nil)
switch {
case code != "":
token, err = oauth2Config.Exchange(a.ctx, code)
case refresh != "":
t := &oauth2.Token{
RefreshToken: refresh,
Expiry: time.Now().Add(-time.Hour),
}
token, err = oauth2Config.TokenSource(a.ctx, t).Token()
default:
http.Error(w, "no code in request", 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(rawIDToken)
if err != nil {
http.Error(w, fmt.Sprintf("Failed to verify ID token: %v", err), http.StatusInternalServerError)
return
}
var claims json.RawMessage
idToken.Claims(&claims)
buff := new(bytes.Buffer)
json.Indent(buff, []byte(claims), "", " ")
renderToken(w, a.redirectURI, rawIDToken, token.RefreshToken, buff.Bytes())
}
package main
import (
"html/template"
"log"
"net/http"
)
var indexTmpl = template.Must(template.New("index.html").Parse(`<html>
<body>
<form action="/login">
<p>
Authenticate for:<input type="text" name="cross_client" placeholder="list of client-ids">
</p>
<p>
Extra scopes:<input type="text" name="extra_scopes" placeholder="list of scopes">
</p>
<input type="submit" value="Login">
</form>
</body>
</html>`))
func renderIndex(w http.ResponseWriter) {
renderTemplate(w, indexTmpl, nil)
}
type tokenTmplData struct {
IDToken string
RefreshToken string
RedirectURL string
Claims string
}
var tokenTmpl = template.Must(template.New("token.html").Parse(`<html>
<head>
<style>
/* make pre wrap */
pre {
white-space: pre-wrap; /* css-3 */
white-space: -moz-pre-wrap; /* Mozilla, since 1999 */
white-space: -pre-wrap; /* Opera 4-6 */
white-space: -o-pre-wrap; /* Opera 7 */
word-wrap: break-word; /* Internet Explorer 5.5+ */
}
</style>
</head>
<body>
<p> Token: <pre><code>{{ .IDToken }}</code></pre></p>
<p> Claims: <pre><code>{{ .Claims }}</code></pre></p>
<p> Refresh Token: <pre><code>{{ .RefreshToken }}</code></pre></p>
<p><a href="{{ .RedirectURL }}?refresh_token={{ .RefreshToken }}">Redeem refresh token</a><p>
</body>
</html>
`))
func renderToken(w http.ResponseWriter, redirectURL, idToken, refreshToken string, claims []byte) {
renderTemplate(w, tokenTmpl, tokenTmplData{
IDToken: idToken,
RefreshToken: refreshToken,
RedirectURL: redirectURL,
Claims: string(claims),
})
}
func renderTemplate(w http.ResponseWriter, tmpl *template.Template, data interface{}) {
err := tmpl.Execute(w, data)
if err == nil {
return
}
switch err := err.(type) {
case *template.Error:
// An ExecError guarentees that Execute has not written to the underlying reader.
log.Printf("Error rendering template %s: %s", tmpl.Name(), err)
// TODO(ericchiang): replace with better internal server error.
http.Error(w, "Internal server error", http.StatusInternalServerError)
default:
// An error with the underlying write, such as the connection being
// dropped. Ignore for now.
}
}
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