fix: prevent double totp submissions

* feat: add x-tinyauth-location to nginx response

Solves #773. Normally you let Nginx handle the login URL creation but with this "hack"
we can set an arbitary header with where Tinyauth wants the user to go to. Later the
Nginx error page can get this header and redirect accordingly.

* tests: fix assert.Equal order

frontend/bun.lock

@@ -19,7 +19,6 @@
         "i18next": "^26.0.3",
         "i18next-browser-languagedetector": "^8.2.1",
         "i18next-resources-to-backend": "^1.2.1",
-        "input-otp": "^1.4.2",
         "lucide-react": "^1.7.0",
         "next-themes": "^0.4.6",
         "radix-ui": "^1.4.3",
@@ -623,8 +622,6 @@
 
     "inline-style-parser": ["inline-style-parser@0.2.4", "", {}, "sha512-0aO8FkhNZlj/ZIbNi7Lxxr12obT7cL1moPfE4tg1LkX7LlLfC6DeX4l2ZEud1ukP9jNQyNnfzQVqwbwmAATY4Q=="],
 
-    "input-otp": ["input-otp@1.4.2", "", { "peerDependencies": { "react": "^16.8 || ^17.0 || ^18.0 || ^19.0.0 || ^19.0.0-rc", "react-dom": "^16.8 || ^17.0 || ^18.0 || ^19.0.0 || ^19.0.0-rc" } }, "sha512-l3jWwYNvrEa6NTCt7BECfCm48GvwuZzkoeG3gBL2w4CHeOXW3eKFmf9UNYkNfYc3mxMrthMnxjIE07MT0zLBQA=="],
-
     "is-alphabetical": ["is-alphabetical@2.0.1", "", {}, "sha512-FWyyY60MeTNyeSRpkM2Iry0G9hpr7/9kD40mD/cGQEuilcZYS4okz8SN2Q6rLCJ8gbCt6fN+rC+6tMGS99LaxQ=="],
 
     "is-alphanumerical": ["is-alphanumerical@2.0.1", "", { "dependencies": { "is-alphabetical": "^2.0.0", "is-decimal": "^2.0.0" } }, "sha512-hmbYhX/9MUMF5uh7tOXyK/n0ZvWpad5caBA17GsC6vyuCqaWliRG5K1qS9inmUhEMaOBIW7/whAnSwveW/LtZw=="],

frontend/package.json

@@ -25,7 +25,6 @@
     "i18next": "^26.0.3",
     "i18next-browser-languagedetector": "^8.2.1",
     "i18next-resources-to-backend": "^1.2.1",
-    "input-otp": "^1.4.2",
     "lucide-react": "^1.7.0",
     "next-themes": "^0.4.6",
     "radix-ui": "^1.4.3",

frontend/src/components/auth/totp-form.tsx

@@ -1,14 +1,10 @@
 import { Form, FormControl, FormField, FormItem } from "../ui/form";
-import {
-  InputOTP,
-  InputOTPGroup,
-  InputOTPSeparator,
-  InputOTPSlot,
-} from "../ui/input-otp";
+import { Input } from "../ui/input";
 import { zodResolver } from "@hookform/resolvers/zod";
 import { useForm } from "react-hook-form";
 import { totpSchema, TotpSchema } from "@/schemas/totp-schema";
 import { useTranslation } from "react-i18next";
+import { useRef } from "react";
 import z from "zod";
 
 interface Props {
@@ -19,6 +15,7 @@ interface Props {
 export const TotpForm = (props: Props) => {
   const { formId, onSubmit } = props;
   const { t } = useTranslation();
+  const autoSubmittedRef = useRef(false);
 
   z.config({
     customError: (iss) =>
@@ -29,14 +26,19 @@ export const TotpForm = (props: Props) => {
     resolver: zodResolver(totpSchema),
   });
 
-  const handleChange = (value: string) => {
-    form.setValue("code", value, { shouldDirty: true, shouldValidate: true });
-
-    if (value.length === 6) {
-      onSubmit({ code: value });
+  const handleChange = (e: React.ChangeEvent<HTMLInputElement>) => {
+    const value = e.target.value.replace(/\D/g, "").slice(0, 6);
+    form.setValue("code", value, { shouldDirty: true, shouldValidate: false });
+    if (value.length === 6 && !autoSubmittedRef.current) {
+      autoSubmittedRef.current = true;
+      form.handleSubmit(onSubmit)();
+      return;
     }
+    autoSubmittedRef.current = false;
   };
 
+  // Note: This is not the best UX, ideally we would want https://github.com/guilhermerodz/input-otp
+  // but some password managers cannot autofill the inputs (see #92) so, simple input it is
   return (
     <Form {...form}>
       <form id={formId} onSubmit={form.handleSubmit(onSubmit)}>
@@ -46,25 +48,17 @@ export const TotpForm = (props: Props) => {
           render={({ field }) => (
             <FormItem>
               <FormControl>
-                <InputOTP
-                  maxLength={6}
+                <Input
                   {...field}
+                  type="text"
+                  inputMode="numeric"
                   autoComplete="one-time-code"
                   autoFocus
+                  maxLength={6}
+                  placeholder="XXXXXX"
                   onChange={handleChange}
-                >
-                  <InputOTPGroup>
-                    <InputOTPSlot index={0} />
-                    <InputOTPSlot index={1} />
-                    <InputOTPSlot index={2} />
-                  </InputOTPGroup>
-                  <InputOTPSeparator />
-                  <InputOTPGroup>
-                    <InputOTPSlot index={3} />
-                    <InputOTPSlot index={4} />
-                    <InputOTPSlot index={5} />
-                  </InputOTPGroup>
-                </InputOTP>
+                  className="text-center"
+                />
               </FormControl>
             </FormItem>
           )}

frontend/src/components/ui/input-otp.tsx

@@ -1,75 +0,0 @@
-import * as React from "react";
-import { OTPInput, OTPInputContext } from "input-otp";
-import { MinusIcon } from "lucide-react";
-
-import { cn } from "@/lib/utils";
-
-function InputOTP({
-  className,
-  containerClassName,
-  ...props
-}: React.ComponentProps<typeof OTPInput> & {
-  containerClassName?: string;
-}) {
-  return (
-    <OTPInput
-      data-slot="input-otp"
-      containerClassName={cn(
-        "flex items-center gap-2 has-disabled:opacity-50",
-        containerClassName,
-      )}
-      className={cn("disabled:cursor-not-allowed", className)}
-      {...props}
-    />
-  );
-}
-
-function InputOTPGroup({ className, ...props }: React.ComponentProps<"div">) {
-  return (
-    <div
-      data-slot="input-otp-group"
-      className={cn("flex items-center", className)}
-      {...props}
-    />
-  );
-}
-
-function InputOTPSlot({
-  index,
-  className,
-  ...props
-}: React.ComponentProps<"div"> & {
-  index: number;
-}) {
-  const inputOTPContext = React.useContext(OTPInputContext);
-  const { char, hasFakeCaret, isActive } = inputOTPContext?.slots[index] ?? {};
-
-  return (
-    <div
-      data-slot="input-otp-slot"
-      data-active={isActive}
-      className={cn(
-        "data-[active=true]:border-ring data-[active=true]:ring-ring/50 data-[active=true]:aria-invalid:ring-destructive/20 dark:data-[active=true]:aria-invalid:ring-destructive/40 aria-invalid:border-destructive data-[active=true]:aria-invalid:border-destructive dark:bg-input/30 border-input relative flex h-9 w-9 items-center justify-center border-y border-r text-sm shadow-xs transition-all outline-none first:rounded-l-md first:border-l last:rounded-r-md data-[active=true]:z-10 data-[active=true]:ring-[3px]",
-        className,
-      )}
-      {...props}
-    >
-      {char}
-      {hasFakeCaret && (
-        <div className="pointer-events-none absolute inset-0 flex items-center justify-center">
-          <div className="animate-caret-blink bg-foreground h-4 w-px duration-1000" />
-        </div>
-      )}
-    </div>
-  );
-}
-
-function InputOTPSeparator({ ...props }: React.ComponentProps<"div">) {
-  return (
-    <div data-slot="input-otp-separator" role="separator" {...props}>
-      <MinusIcon />
-    </div>
-  );
-}
-
-export { InputOTP, InputOTPGroup, InputOTPSlot, InputOTPSeparator };

frontend/src/pages/totp-page.tsx

@@ -74,7 +74,7 @@ export const TotpPage = () => {
         <CardTitle className="text-xl">{t("totpTitle")}</CardTitle>
         <CardDescription>{t("totpSubtitle")}</CardDescription>
       </CardHeader>
-      <CardContent className="flex flex-col items-center">
+      <CardContent>
         <TotpForm
           formId={formId}
           onSubmit={(values) => totpMutation.mutate(values)}

internal/controller/proxy_controller.go

@@ -131,14 +131,6 @@ func (controller *ProxyController) proxyHandler(c *gin.Context) {
 	}
 
 	if !controller.auth.CheckIP(acls.IP, clientIP) {
-		if !controller.useBrowserResponse(proxyCtx) {
-			c.JSON(401, gin.H{
-				"status":  401,
-				"message": "Unauthorized",
-			})
-			return
-		}
-
 		queries, err := query.Values(config.UnauthorizedQuery{
 			Resource: strings.Split(proxyCtx.Host, ".")[0],
 			IP:       clientIP,
@@ -146,11 +138,22 @@ func (controller *ProxyController) proxyHandler(c *gin.Context) {
 
 		if err != nil {
 			tlog.App.Error().Err(err).Msg("Failed to encode unauthorized query")
-			c.Redirect(http.StatusTemporaryRedirect, fmt.Sprintf("%s/error", controller.config.AppURL))
+			controller.handleError(c, proxyCtx)
 			return
 		}
 
-		c.Redirect(http.StatusTemporaryRedirect, fmt.Sprintf("%s/unauthorized?%s", controller.config.AppURL, queries.Encode()))
+		redirectURL := fmt.Sprintf("%s/unauthorized?%s", controller.config.AppURL, queries.Encode())
+
+		if !controller.useBrowserResponse(proxyCtx) {
+			c.Header("x-tinyauth-location", redirectURL)
+			c.JSON(401, gin.H{
+				"status":  401,
+				"message": "Unauthorized",
+			})
+			return
+		}
+
+		c.Redirect(http.StatusTemporaryRedirect, redirectURL)
 		return
 	}
 
@@ -175,21 +178,13 @@ func (controller *ProxyController) proxyHandler(c *gin.Context) {
 		if !userAllowed {
 			tlog.App.Warn().Str("user", userContext.Username).Str("resource", strings.Split(proxyCtx.Host, ".")[0]).Msg("User not allowed to access resource")
 
-			if !controller.useBrowserResponse(proxyCtx) {
-				c.JSON(403, gin.H{
-					"status":  403,
-					"message": "Forbidden",
-				})
-				return
-			}
-
 			queries, err := query.Values(config.UnauthorizedQuery{
 				Resource: strings.Split(proxyCtx.Host, ".")[0],
 			})
 
 			if err != nil {
 				tlog.App.Error().Err(err).Msg("Failed to encode unauthorized query")
-				c.Redirect(http.StatusTemporaryRedirect, fmt.Sprintf("%s/error", controller.config.AppURL))
+				controller.handleError(c, proxyCtx)
 				return
 			}
 
@@ -199,7 +194,18 @@ func (controller *ProxyController) proxyHandler(c *gin.Context) {
 				queries.Set("username", userContext.Username)
 			}
 
-			c.Redirect(http.StatusTemporaryRedirect, fmt.Sprintf("%s/unauthorized?%s", controller.config.AppURL, queries.Encode()))
+			redirectURL := fmt.Sprintf("%s/unauthorized?%s", controller.config.AppURL, queries.Encode())
+
+			if !controller.useBrowserResponse(proxyCtx) {
+				c.Header("x-tinyauth-location", redirectURL)
+				c.JSON(403, gin.H{
+					"status":  403,
+					"message": "Forbidden",
+				})
+				return
+			}
+
+			c.Redirect(http.StatusTemporaryRedirect, redirectURL)
 			return
 		}
 
@@ -215,14 +221,6 @@ func (controller *ProxyController) proxyHandler(c *gin.Context) {
 			if !groupOK {
 				tlog.App.Warn().Str("user", userContext.Username).Str("resource", strings.Split(proxyCtx.Host, ".")[0]).Msg("User groups do not match resource requirements")
 
-				if !controller.useBrowserResponse(proxyCtx) {
-					c.JSON(403, gin.H{
-						"status":  403,
-						"message": "Forbidden",
-					})
-					return
-				}
-
 				queries, err := query.Values(config.UnauthorizedQuery{
 					Resource: strings.Split(proxyCtx.Host, ".")[0],
 					GroupErr: true,
@@ -230,7 +228,7 @@ func (controller *ProxyController) proxyHandler(c *gin.Context) {
 
 				if err != nil {
 					tlog.App.Error().Err(err).Msg("Failed to encode unauthorized query")
-					c.Redirect(http.StatusTemporaryRedirect, fmt.Sprintf("%s/error", controller.config.AppURL))
+					controller.handleError(c, proxyCtx)
 					return
 				}
 
@@ -240,7 +238,18 @@ func (controller *ProxyController) proxyHandler(c *gin.Context) {
 					queries.Set("username", userContext.Username)
 				}
 
-				c.Redirect(http.StatusTemporaryRedirect, fmt.Sprintf("%s/unauthorized?%s", controller.config.AppURL, queries.Encode()))
+				redirectURL := fmt.Sprintf("%s/unauthorized?%s", controller.config.AppURL, queries.Encode())
+
+				if !controller.useBrowserResponse(proxyCtx) {
+					c.Header("x-tinyauth-location", redirectURL)
+					c.JSON(403, gin.H{
+						"status":  403,
+						"message": "Forbidden",
+					})
+					return
+				}
+
+				c.Redirect(http.StatusTemporaryRedirect, redirectURL)
 				return
 			}
 		}
@@ -266,7 +275,20 @@ func (controller *ProxyController) proxyHandler(c *gin.Context) {
 		return
 	}
 
+	queries, err := query.Values(config.RedirectQuery{
+		RedirectURI: fmt.Sprintf("%s://%s%s", proxyCtx.Proto, proxyCtx.Host, proxyCtx.Path),
+	})
+
+	if err != nil {
+		tlog.App.Error().Err(err).Msg("Failed to encode redirect URI query")
+		controller.handleError(c, proxyCtx)
+		return
+	}
+
+	redirectURL := fmt.Sprintf("%s/login?%s", controller.config.AppURL, queries.Encode())
+
 	if !controller.useBrowserResponse(proxyCtx) {
+		c.Header("x-tinyauth-location", redirectURL)
 		c.JSON(401, gin.H{
 			"status":  401,
 			"message": "Unauthorized",
@@ -274,17 +296,7 @@ func (controller *ProxyController) proxyHandler(c *gin.Context) {
 		return
 	}
 
-	queries, err := query.Values(config.RedirectQuery{
-		RedirectURI: fmt.Sprintf("%s://%s%s", proxyCtx.Proto, proxyCtx.Host, proxyCtx.Path),
-	})
-
-	if err != nil {
-		tlog.App.Error().Err(err).Msg("Failed to encode redirect URI query")
-		c.Redirect(http.StatusTemporaryRedirect, fmt.Sprintf("%s/error", controller.config.AppURL))
-		return
-	}
-
-	c.Redirect(http.StatusTemporaryRedirect, fmt.Sprintf("%s/login?%s", controller.config.AppURL, queries.Encode()))
+	c.Redirect(http.StatusTemporaryRedirect, redirectURL)
 }
 
 func (controller *ProxyController) setHeaders(c *gin.Context, acls config.App) {
@@ -306,7 +318,10 @@ func (controller *ProxyController) setHeaders(c *gin.Context, acls config.App) {
 }
 
 func (controller *ProxyController) handleError(c *gin.Context, proxyCtx ProxyContext) {
+	redirectURL := fmt.Sprintf("%s/error", controller.config.AppURL)
+
 	if !controller.useBrowserResponse(proxyCtx) {
+		c.Header("x-tinyauth-location", redirectURL)
 		c.JSON(500, gin.H{
 			"status":  500,
 			"message": "Internal Server Error",
@@ -314,7 +329,7 @@ func (controller *ProxyController) handleError(c *gin.Context, proxyCtx ProxyCon
 		return
 	}
 
-	c.Redirect(http.StatusTemporaryRedirect, fmt.Sprintf("%s/error", controller.config.AppURL))
+	c.Redirect(http.StatusTemporaryRedirect, redirectURL)
 }
 
 func (controller *ProxyController) getHeader(c *gin.Context, header string) (string, bool) {

internal/controller/proxy_controller_test.go

@@ -116,8 +116,7 @@ func TestProxyController(t *testing.T) {
 
 				assert.Equal(t, 307, recorder.Code)
 				location := recorder.Header().Get("Location")
-				assert.Contains(t, location, "https://tinyauth.example.com/login?redirect_uri=")
-				assert.Contains(t, location, "https%3A%2F%2Ftest.example.com%2F")
+				assert.Equal(t, "https://tinyauth.example.com/login?redirect_uri=https%3A%2F%2Ftest.example.com%2F", location)
 			},
 		},
 		{
@@ -129,6 +128,8 @@ func TestProxyController(t *testing.T) {
 				req.Header.Set("user-agent", browserUserAgent)
 				router.ServeHTTP(recorder, req)
 				assert.Equal(t, 401, recorder.Code)
+				location := recorder.Header().Get("x-tinyauth-location")
+				assert.Equal(t, "https://tinyauth.example.com/login?redirect_uri=https%3A%2F%2Ftest.example.com%2F", location)
 			},
 		},
 		{
@@ -142,8 +143,7 @@ func TestProxyController(t *testing.T) {
 				router.ServeHTTP(recorder, req)
 				assert.Equal(t, 307, recorder.Code)
 				location := recorder.Header().Get("Location")
-				assert.Contains(t, location, "https://tinyauth.example.com/login?redirect_uri=")
-				assert.Contains(t, location, "https%3A%2F%2Ftest.example.com%2Fhello")
+				assert.Equal(t, "https://tinyauth.example.com/login?redirect_uri=https%3A%2F%2Ftest.example.com%2Fhello", location)
 			},
 		},
 		{
@@ -159,8 +159,7 @@ func TestProxyController(t *testing.T) {
 
 				assert.Equal(t, 307, recorder.Code)
 				location := recorder.Header().Get("Location")
-				assert.Contains(t, location, "https://tinyauth.example.com/login?redirect_uri=")
-				assert.Contains(t, location, "https%3A%2F%2Ftest.example.com%2F")
+				assert.Equal(t, "https://tinyauth.example.com/login?redirect_uri=https%3A%2F%2Ftest.example.com%2F", location)
 			},
 		},
 		{
@@ -174,6 +173,8 @@ func TestProxyController(t *testing.T) {
 				req.Header.Set("user-agent", browserUserAgent)
 				router.ServeHTTP(recorder, req)
 				assert.Equal(t, 401, recorder.Code)
+				location := recorder.Header().Get("x-tinyauth-location")
+				assert.Equal(t, "https://tinyauth.example.com/login?redirect_uri=https%3A%2F%2Ftest.example.com%2F", location)
 			},
 		},
 		{
@@ -189,8 +190,7 @@ func TestProxyController(t *testing.T) {
 				router.ServeHTTP(recorder, req)
 				assert.Equal(t, 307, recorder.Code)
 				location := recorder.Header().Get("Location")
-				assert.Contains(t, location, "https://tinyauth.example.com/login?redirect_uri=")
-				assert.Contains(t, location, "https%3A%2F%2Ftest.example.com%2Fhello")
+				assert.Equal(t, "https://tinyauth.example.com/login?redirect_uri=https%3A%2F%2Ftest.example.com%2Fhello", location)
 			},
 		},
 		{