slack-status-cli/auth.go

147 lines
3.7 KiB
Go

package main
import (
"context"
"crypto/tls"
_ "embed"
"errors"
"fmt"
"log"
"net/http"
"strings"
"time"
"github.com/slack-go/slack"
)
var (
// These are set via build flags but can be overridden via environment variables.
defaultClientID = ""
defaultClientSecret = ""
//go:embed "certs/cert.pem"
certPem []byte
//go:embed "certs/key.pem"
keyPem []byte
)
const (
httpReadTimeout = 5 * time.Second
httpWriteTimeout = 10 * time.Second
httpIdleTimeout = 120 * time.Second
)
type slackApp struct {
clientID, clientSecret, redirectURI string
scopes, userScopes []string
listenHost, listenPath string
}
func (app slackApp) getAuthURL() string {
scopes := strings.Join(app.scopes, ",")
userScopes := strings.Join(app.userScopes, ",")
return fmt.Sprintf(
"https://slack.com/oauth/authorize?scope=%s&user_scope=%s&client_id=%s&redirect_uri=%s",
scopes,
userScopes,
app.clientID,
app.redirectURI,
)
}
func (app slackApp) listenForCode() (string, error) {
// start an http listener and listen for the redirect and return the code from params
var code string
certPath, err := getConfigFilePath("cert.pem")
if err != nil {
return "", fmt.Errorf("failed checking config path for cert: %w", err)
}
keyPath, err := getConfigFilePath("key.pem")
if err != nil {
return "", fmt.Errorf("failed checking config path for key: %w", err)
}
tlsCfg := &tls.Config{
MinVersion: tls.VersionTLS12,
}
// If config files don't exist, use embedded
if !fileExists(certPath) && !fileExists(keyPath) {
cert, err := tls.X509KeyPair(certPem, keyPem)
if err != nil {
return "", fmt.Errorf("failed loading embedded key pair: %w", err)
}
tlsCfg.Certificates = make([]tls.Certificate, 1)
tlsCfg.Certificates[0] = cert
// Empty out paths since they don't exist so embedded certs will be used
certPath = ""
keyPath = ""
}
// Also, should generate TLS certificate to use since https is a required scheme
server := http.Server{
Addr: app.listenHost,
ReadTimeout: httpReadTimeout,
WriteTimeout: httpWriteTimeout,
IdleTimeout: httpIdleTimeout,
TLSConfig: tlsCfg,
}
http.HandleFunc(app.listenPath, func(w http.ResponseWriter, r *http.Request) {
codes := r.URL.Query()["code"]
if len(codes) == 0 {
log.Fatal("no oauth code found in response")
}
code = codes[0]
fmt.Fprintf(w, "Got code %s", code)
// Shutdown after response
go func() {
if err := server.Shutdown(context.Background()); err != nil {
fmt.Println("Fatal?")
log.Fatal(err)
}
}()
})
if err := server.ListenAndServeTLS(certPath, keyPath); err != nil && !errors.Is(err, http.ErrServerClosed) {
return "", err
}
return code, nil
}
func authenticate() (string, error) {
app := slackApp{
userScopes: []string{"dnd:write", "users.profile:write", "team:read"},
scopes: []string{"dnd:write", "users.profile:write", "team:read"},
clientID: getEnvOrDefault("CLIENT_ID", defaultClientID),
clientSecret: getEnvOrDefault("CLIENT_SECRET", defaultClientSecret),
redirectURI: "https://localhost:8888/auth",
listenHost: "localhost:8888",
listenPath: "/auth",
}
fmt.Println("To authenticate, go to the following URL:")
fmt.Println("NOTE: After you authenticate with Slack, it will redirect you to a server running on your local computer. Your browser will present a security error because it cann't verify the server. You will need to manually add an exception or tell your browser to proceed anyway.")
fmt.Println(app.getAuthURL())
code, err := app.listenForCode()
if err != nil {
return "", err
}
accessToken, _, err := slack.GetOAuthToken(&http.Client{}, app.clientID, app.clientSecret, code, app.redirectURI)
if err != nil {
return "", err
}
return accessToken, nil
}