Add a backend request login interface implementation

oauthproxy.go

@@ -124,7 +124,12 @@ func NewOAuthProxy(opts *options.Options, validator func(string) bool) (*OAuthPr
 	}
 
 	var basicAuthValidator basic.Validator
-	if opts.HtpasswdFile != "" {
+	if opts.RedirectSignUrl != "" {
+		basicAuthValidator = &basic.AppLoginValidator{
+			LoginURL: opts.RedirectSignUrl,
+			Timeout:  60 * time.Second,
+		}
+	} else if opts.HtpasswdFile != "" {
 		logger.Printf("using htpasswd file: %s", opts.HtpasswdFile)
 		var err error
 		basicAuthValidator, err = basic.NewHTPasswdValidator(opts.HtpasswdFile)

pkg/apis/options/options.go

@@ -33,6 +33,7 @@ type Options struct {
 	EmailDomains            []string `flag:"email-domain" cfg:"email_domains"`
 	WhitelistDomains        []string `flag:"whitelist-domain" cfg:"whitelist_domains"`
 	HtpasswdFile            string   `flag:"htpasswd-file" cfg:"htpasswd_file"`
+	RedirectSignUrl         string   `flag:"redirect-sign-url" cfg:"redirect-sign-url"`
 	HtpasswdUserGroups      []string `flag:"htpasswd-user-group" cfg:"htpasswd_user_groups"`
 
 	Cookie    Cookie         `cfg:",squash"`
@@ -140,6 +141,7 @@ func NewFlagSet() *pflag.FlagSet {
 	flagSet.StringSlice("whitelist-domain", []string{}, "allowed domains for redirection after authentication. Prefix domain with a . or a *. to allow subdomains (eg .example.com, *.example.com)")
 	flagSet.String("authenticated-emails-file", "", "authenticate against emails via file (one per line)")
 	flagSet.String("htpasswd-file", "", "additionally authenticate against a htpasswd file. Entries must be created with \"htpasswd -B\" for bcrypt encryption")
+	flagSet.String("redirect-sign-url", "", "additionally sign url using http")
 	flagSet.StringSlice("htpasswd-user-group", []string{}, "the groups to be set on sessions for htpasswd users (may be given multiple times)")
 	flagSet.String("proxy-prefix", "/oauth2", "the url root path that this proxy should be nested under (e.g. /<oauth2>/sign_in)")
 	flagSet.String("ping-path", "/ping", "the ping endpoint that can be used for basic health checks")

pkg/authentication/basic/http_login.go

@@ -0,0 +1,51 @@
+package basic
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"time"
+)
+
+// AppLoginValidator
+type AppLoginValidator struct {
+	LoginURL string
+	Timeout  time.Duration
+}
+
+type loginRequest struct {
+	Username string `json:"username"`
+	Password string `json:"password"`
+}
+
+// Validate implement Validator interface
+func (v *AppLoginValidator) Validate(user, password string) bool {
+	reqBody := loginRequest{
+		Username: user,
+		Password: password,
+	}
+	data, _ := json.Marshal(reqBody)
+
+	client := &http.Client{Timeout: v.Timeout}
+	resp, err := client.Post(v.LoginURL, "application/json", bytes.NewReader(data))
+	if err != nil {
+		println(err.Error())
+		return false
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != 200 {
+		body, err := io.ReadAll(resp.Body)
+		if err != nil {
+			fmt.Printf("ReadAll error: %v\n", err)
+			return false
+		}
+
+		fmt.Printf("Response body: %s\n", string(body))
+		return false
+	}
+
+	return true
+}