feat: email verification for document signing 2FA

apps/remix/app/components/general/document-signing/document-signing-auth-2fa.tsx

@@ -8,6 +8,7 @@ import { z } from 'zod';
 
 import { AppError } from '@documenso/lib/errors/app-error';
 import { DocumentAuth, type TRecipientActionAuth } from '@documenso/lib/types/document-auth';
+import { trpc } from '@documenso/trpc/react';
 import { Alert, AlertDescription, AlertTitle } from '@documenso/ui/primitives/alert';
 import { Button } from '@documenso/ui/primitives/button';
 import { DialogFooter } from '@documenso/ui/primitives/dialog';
@@ -20,6 +21,8 @@ import {
   FormMessage,
 } from '@documenso/ui/primitives/form/form';
 import { PinInput, PinInputGroup, PinInputSlot } from '@documenso/ui/primitives/pin-input';
+import { Tabs, TabsList, TabsTrigger } from '@documenso/ui/primitives/tabs';
+import { useToast } from '@documenso/ui/primitives/use-toast';
 
 import { EnableAuthenticatorAppDialog } from '~/components/forms/2fa/enable-authenticator-app-dialog';
 
@@ -51,6 +54,7 @@ export const DocumentSigningAuth2FA = ({
 }: DocumentSigningAuth2FAProps) => {
   const { recipient, user, isCurrentlyAuthenticating, setIsCurrentlyAuthenticating } =
     useRequiredDocumentSigningAuthContext();
+  const { toast } = useToast();
 
   const form = useForm<T2FAAuthFormSchema>({
     resolver: zodResolver(Z2FAAuthFormSchema),
@@ -60,27 +64,71 @@ export const DocumentSigningAuth2FA = ({
   });
 
   const [is2FASetupSuccessful, setIs2FASetupSuccessful] = useState(false);
+  const [isEmailCodeSent, setIsEmailCodeSent] = useState(false);
+  const [isEmailCodeSending, setIsEmailCodeSending] = useState(false);
   const [formErrorCode, setFormErrorCode] = useState<string | null>(null);
+  const [verificationMethod, setVerificationMethod] = useState<'app' | 'email'>(
+    user?.twoFactorEnabled ? 'app' : 'email',
+  );
+
+  const sendVerificationMutation = trpc.auth.sendEmailVerification.useMutation({
+    onSuccess: () => {
+      setIsEmailCodeSent(true);
+      toast({
+        title: 'Verification code sent',
+        description: `A verification code has been sent to ${recipient.email}`,
+      });
+    },
+    onError: (error) => {
+      console.error('Failed to send verification code', error);
+      toast({
+        title: 'Failed to send verification code',
+        description: 'Please try again or contact support',
+        variant: 'destructive',
+      });
+    },
+    onSettled: () => {
+      setIsEmailCodeSending(false);
+    },
+  });
+
+  const verifyCodeMutation = trpc.auth.verifyEmailCode.useMutation();
+
+  const sendEmailVerificationCode = async () => {
+    try {
+      setIsEmailCodeSending(true);
+      await sendVerificationMutation.mutateAsync({
+        recipientId: recipient.id,
+      });
+    } catch (error) {
+      // Error is handled in the mutation callbacks
+    }
+  };
 
   const onFormSubmit = async ({ token }: T2FAAuthFormSchema) => {
     try {
       setIsCurrentlyAuthenticating(true);
 
+      if (verificationMethod === 'email') {
+        // Verify the email code first
+        await verifyCodeMutation.mutateAsync({
+          code: token,
+          recipientId: recipient.id,
+        });
+      }
+
       await onReauthFormSubmit({
         type: DocumentAuth.TWO_FACTOR_AUTH,
         token,
       });
 
       setIsCurrentlyAuthenticating(false);
-
       onOpenChange(false);
     } catch (err) {
       setIsCurrentlyAuthenticating(false);
 
       const error = AppError.parseError(err);
       setFormErrorCode(error.code);
-
-      // Todo: Alert.
     }
   };
 
@@ -91,20 +139,40 @@ export const DocumentSigningAuth2FA = ({
 
     setIs2FASetupSuccessful(false);
     setFormErrorCode(null);
+    setIsEmailCodeSent(false);
+
+    if (open && !user?.twoFactorEnabled) {
+      setVerificationMethod('email');
+    }
 
     // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, [open]);
+  }, [open, user?.twoFactorEnabled]);
 
-  if (!user?.twoFactorEnabled && !is2FASetupSuccessful) {
+  useEffect(() => {
+    if (open && verificationMethod === 'email' && !isEmailCodeSent && !isEmailCodeSending) {
+      void sendEmailVerificationCode();
+    }
+  }, [open, verificationMethod, isEmailCodeSent, isEmailCodeSending]);
+
+  if (verificationMethod === 'app' && !user?.twoFactorEnabled && !is2FASetupSuccessful) {
     return (
       <div className="space-y-4">
+        <Tabs
+          value={verificationMethod}
+          onValueChange={(val) => setVerificationMethod(val as 'app' | 'email')}
+        >
+          <TabsList className="grid w-full grid-cols-2">
+            <TabsTrigger value="app">Authenticator App</TabsTrigger>
+            <TabsTrigger value="email">Email Verification</TabsTrigger>
+          </TabsList>
+        </Tabs>
+
         <Alert variant="warning">
           <AlertDescription>
             <p>
               {recipient.role === RecipientRole.VIEWER && actionTarget === 'DOCUMENT' ? (
                 <Trans>You need to setup 2FA to mark this document as viewed.</Trans>
               ) : (
-                // Todo: Translate
                 `You need to setup 2FA to ${actionVerb.toLowerCase()} this ${actionTarget.toLowerCase()}.`
               )}
             </p>
@@ -129,59 +197,113 @@ export const DocumentSigningAuth2FA = ({
   }
 
   return (
-    <Form {...form}>
-      <form onSubmit={form.handleSubmit(onFormSubmit)}>
-        <fieldset disabled={isCurrentlyAuthenticating}>
-          <div className="space-y-4">
-            <FormField
-              control={form.control}
-              name="token"
-              render={({ field }) => (
-                <FormItem>
-                  <FormLabel required>2FA token</FormLabel>
+    <div className="space-y-4">
+      {user?.twoFactorEnabled && (
+        <Tabs
+          value={verificationMethod}
+          onValueChange={(val) => setVerificationMethod(val as 'app' | 'email')}
+        >
+          <TabsList className="grid w-full grid-cols-2">
+            <TabsTrigger value="app">Authenticator App</TabsTrigger>
+            <TabsTrigger value="email">Email Verification</TabsTrigger>
+          </TabsList>
+        </Tabs>
+      )}
 
-                  <FormControl>
-                    <PinInput {...field} value={field.value ?? ''} maxLength={6}>
-                      {Array(6)
-                        .fill(null)
-                        .map((_, i) => (
-                          <PinInputGroup key={i}>
-                            <PinInputSlot index={i} />
-                          </PinInputGroup>
-                        ))}
-                    </PinInput>
-                  </FormControl>
-
-                  <FormMessage />
-                </FormItem>
-              )}
-            />
-
-            {formErrorCode && (
-              <Alert variant="destructive">
-                <AlertTitle>
-                  <Trans>Unauthorized</Trans>
-                </AlertTitle>
-                <AlertDescription>
-                  <Trans>
-                    We were unable to verify your details. Please try again or contact support
-                  </Trans>
-                </AlertDescription>
-              </Alert>
+      {verificationMethod === 'email' && (
+        <Alert variant="secondary">
+          <AlertDescription>
+            {isEmailCodeSent ? (
+              <p>
+                <Trans>
+                  A verification code has been sent to {recipient.email}. Please enter it below to
+                  continue.
+                </Trans>
+              </p>
+            ) : (
+              <p>
+                <Trans>
+                  We'll send a verification code to {recipient.email} to verify your identity.
+                </Trans>
+              </p>
             )}
+          </AlertDescription>
+        </Alert>
+      )}
 
-            <DialogFooter>
-              <Button type="button" variant="secondary" onClick={() => onOpenChange(false)}>
-                <Trans>Cancel</Trans>
-              </Button>
+      <Form {...form}>
+        <form onSubmit={form.handleSubmit(onFormSubmit)}>
+          <fieldset disabled={isCurrentlyAuthenticating}>
+            <div className="space-y-4">
+              <FormField
+                control={form.control}
+                name="token"
+                render={({ field }) => (
+                  <FormItem>
+                    <FormLabel required>
+                      {verificationMethod === 'app' ? (
+                        <Trans>2FA token</Trans>
+                      ) : (
+                        <Trans>Verification code</Trans>
+                      )}
+                    </FormLabel>
 
-              <Button type="submit" loading={isCurrentlyAuthenticating}>
-                <Trans>{actionTarget === 'DOCUMENT' ? 'Sign Document' : 'Sign Field'}</Trans>
-              </Button>
-            </DialogFooter>
-          </div>
-        </fieldset>
-      </form>
-    </Form>
+                    <FormControl>
+                      <PinInput {...field} value={field.value ?? ''} maxLength={6}>
+                        {Array(6)
+                          .fill(null)
+                          .map((_, i) => (
+                            <PinInputGroup key={i}>
+                              <PinInputSlot index={i} />
+                            </PinInputGroup>
+                          ))}
+                      </PinInput>
+                    </FormControl>
+
+                    <FormMessage />
+                  </FormItem>
+                )}
+              />
+
+              {verificationMethod === 'email' && (
+                <div className="flex justify-center">
+                  <Button
+                    type="button"
+                    variant="link"
+                    disabled={isEmailCodeSending}
+                    onClick={() => void sendEmailVerificationCode()}
+                  >
+                    {isEmailCodeSending ? <Trans>Sending...</Trans> : <Trans>Resend code</Trans>}
+                  </Button>
+                </div>
+              )}
+
+              {formErrorCode && (
+                <Alert variant="destructive">
+                  <AlertTitle>
+                    <Trans>Unauthorized</Trans>
+                  </AlertTitle>
+                  <AlertDescription>
+                    <Trans>
+                      We were unable to verify your details. Please try again or contact support
+                    </Trans>
+                  </AlertDescription>
+                </Alert>
+              )}
+
+              <DialogFooter>
+                <Button type="button" variant="secondary" onClick={() => onOpenChange(false)}>
+                  <Trans>Cancel</Trans>
+                </Button>
+
+                <Button type="submit" loading={isCurrentlyAuthenticating}>
+                  <Trans>{actionTarget === 'DOCUMENT' ? 'Sign Document' : 'Sign Field'}</Trans>
+                </Button>
+              </DialogFooter>
+            </div>
+          </fieldset>
+        </form>
+      </Form>
+    </div>
   );
 };

packages/email/template-components/template-verification-code.tsx

@@ -0,0 +1,43 @@
+import { Trans } from '@lingui/react/macro';
+
+import { Section, Text } from '../components';
+import { TemplateDocumentImage } from './template-document-image';
+
+export type TemplateVerificationCodeProps = {
+  verificationCode: string;
+  assetBaseUrl: string;
+};
+
+export const TemplateVerificationCode = ({
+  verificationCode,
+  assetBaseUrl,
+}: TemplateVerificationCodeProps) => {
+  return (
+    <>
+      <TemplateDocumentImage className="mt-6" assetBaseUrl={assetBaseUrl} />
+
+      <Section className="flex-row items-center justify-center">
+        <Text className="text-primary mx-auto mb-0 max-w-[80%] text-center text-lg font-semibold">
+          <Trans>Your verification code</Trans>
+        </Text>
+
+        <Text className="my-1 text-center text-base text-slate-400">
+          <Trans>Please use the code below to verify your identity for document signing.</Trans>
+        </Text>
+
+        <Text className="my-6 text-center text-3xl font-bold tracking-widest">
+          {verificationCode}
+        </Text>
+
+        <Text className="my-1 text-center text-sm text-slate-400">
+          <Trans>
+            If you did not request this code, you can ignore this email. The code will expire after
+            10 minutes.
+          </Trans>
+        </Text>
+      </Section>
+    </>
+  );
+};
+
+export default TemplateVerificationCode;

packages/email/templates/verification-code.tsx

@@ -0,0 +1,62 @@
+import { msg } from '@lingui/core/macro';
+import { useLingui } from '@lingui/react';
+
+import { Body, Container, Head, Hr, Html, Img, Preview, Section } from '../components';
+import { useBranding } from '../providers/branding';
+import { TemplateFooter } from '../template-components/template-footer';
+import type { TemplateVerificationCodeProps } from '../template-components/template-verification-code';
+import { TemplateVerificationCode } from '../template-components/template-verification-code';
+
+export type VerificationCodeTemplateProps = Partial<TemplateVerificationCodeProps>;
+
+export const VerificationCodeTemplate = ({
+  verificationCode = '000000',
+  assetBaseUrl = 'http://localhost:3002',
+}: VerificationCodeTemplateProps) => {
+  const { _ } = useLingui();
+  const branding = useBranding();
+
+  const previewText = msg`Your verification code for document signing`;
+
+  const getAssetUrl = (path: string) => {
+    return new URL(path, assetBaseUrl).toString();
+  };
+
+  return (
+    <Html>
+      <Head />
+      <Preview>{_(previewText)}</Preview>
+
+      <Body className="mx-auto my-auto font-sans">
+        <Section className="bg-white">
+          <Container className="mx-auto mb-2 mt-8 max-w-xl rounded-lg border border-solid border-slate-200 p-2 backdrop-blur-sm">
+            <Section className="p-2">
+              {branding.brandingEnabled && branding.brandingLogo ? (
+                <Img src={branding.brandingLogo} alt="Branding Logo" className="mb-4 h-6" />
+              ) : (
+                <Img
+                  src={getAssetUrl('/static/logo.png')}
+                  alt="Documenso Logo"
+                  className="mb-4 h-6"
+                />
+              )}
+
+              <TemplateVerificationCode
+                verificationCode={verificationCode}
+                assetBaseUrl={assetBaseUrl}
+              />
+            </Section>
+          </Container>
+
+          <Hr className="mx-auto mt-12 max-w-xl" />
+
+          <Container className="mx-auto max-w-xl">
+            <TemplateFooter isDocument={false} />
+          </Container>
+        </Section>
+      </Body>
+    </Html>
+  );
+};
+
+export default VerificationCodeTemplate;

packages/lib/server-only/2fa/send-email-verification.ts

@@ -0,0 +1,120 @@
+import { createElement } from 'react';
+
+import { msg } from '@lingui/core/macro';
+import { randomInt } from 'crypto';
+
+import { AuthenticationErrorCode } from '@documenso/auth/server/lib/errors/error-codes';
+import { mailer } from '@documenso/email/mailer';
+import { VerificationCodeTemplate } from '@documenso/email/templates/verification-code';
+import { AppError } from '@documenso/lib/errors/app-error';
+import { prisma } from '@documenso/prisma';
+
+import { getI18nInstance } from '../../client-only/providers/i18n-server';
+import { NEXT_PUBLIC_WEBAPP_URL } from '../../constants/app';
+import { FROM_ADDRESS, FROM_NAME } from '../../constants/email';
+import { renderEmailWithI18N } from '../../utils/render-email-with-i18n';
+
+const ExtendedAuthErrorCode = {
+  ...AuthenticationErrorCode,
+  InternalError: 'INTERNAL_ERROR',
+  VerificationNotFound: 'VERIFICATION_NOT_FOUND',
+  VerificationExpired: 'VERIFICATION_EXPIRED',
+};
+
+const VERIFICATION_CODE_EXPIRY = 10 * 60 * 1000;
+
+export type SendEmailVerificationOptions = {
+  userId: number;
+  email: string;
+};
+
+export const sendEmailVerification = async ({ userId, email }: SendEmailVerificationOptions) => {
+  try {
+    const verificationCode = randomInt(100000, 1000000).toString();
+    const i18n = await getI18nInstance();
+
+    await prisma.userTwoFactorEmailVerification.upsert({
+      where: {
+        userId,
+      },
+      create: {
+        userId,
+        verificationCode,
+        expiresAt: new Date(Date.now() + VERIFICATION_CODE_EXPIRY),
+      },
+      update: {
+        verificationCode,
+        expiresAt: new Date(Date.now() + VERIFICATION_CODE_EXPIRY),
+      },
+    });
+
+    const template = createElement(VerificationCodeTemplate, {
+      verificationCode,
+      assetBaseUrl: NEXT_PUBLIC_WEBAPP_URL(),
+    });
+
+    const [html, text] = await Promise.all([
+      renderEmailWithI18N(template, { lang: 'en' }),
+      renderEmailWithI18N(template, { lang: 'en', plainText: true }),
+    ]);
+
+    await mailer.sendMail({
+      to: email,
+      from: {
+        name: FROM_NAME,
+        address: FROM_ADDRESS,
+      },
+      subject: i18n._(msg`Your verification code for document signing`),
+      html,
+      text,
+    });
+
+    return { success: true };
+  } catch (error) {
+    console.error('Error sending email verification', error);
+    throw new AppError(ExtendedAuthErrorCode.InternalError);
+  }
+};
+
+export type VerifyEmailCodeOptions = {
+  userId: number;
+  code: string;
+};
+
+export const verifyEmailCode = async ({ userId, code }: VerifyEmailCodeOptions) => {
+  try {
+    const verification = await prisma.userTwoFactorEmailVerification.findUnique({
+      where: {
+        userId,
+      },
+    });
+
+    if (!verification) {
+      throw new AppError(ExtendedAuthErrorCode.VerificationNotFound);
+    }
+
+    if (verification.expiresAt < new Date()) {
+      throw new AppError(ExtendedAuthErrorCode.VerificationExpired);
+    }
+
+    if (verification.verificationCode !== code) {
+      throw new AppError(AuthenticationErrorCode.InvalidTwoFactorCode);
+    }
+
+    await prisma.userTwoFactorEmailVerification.delete({
+      where: {
+        userId,
+      },
+    });
+
+    return { success: true };
+  } catch (error) {
+    console.error('Error verifying email code', error);
+
+    if (error instanceof AppError) {
+      throw error;
+    }
+
+    throw new AppError(ExtendedAuthErrorCode.InternalError);
+  }
+};

packages/prisma/migrations/20250430202737_add_email_migration/migration.sql

@@ -0,0 +1,12 @@
+-- CreateTable
+CREATE TABLE "UserTwoFactorEmailVerification" (
+    "userId" INTEGER NOT NULL,
+    "verificationCode" TEXT NOT NULL,
+    "expiresAt" TIMESTAMP(3) NOT NULL,
+    "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+
+    CONSTRAINT "UserTwoFactorEmailVerification_pkey" PRIMARY KEY ("userId")
+);
+
+-- AddForeignKey
+ALTER TABLE "UserTwoFactorEmailVerification" ADD CONSTRAINT "UserTwoFactorEmailVerification_userId_fkey" FOREIGN KEY ("userId") REFERENCES "User"("id") ON DELETE CASCADE ON UPDATE CASCADE;

packages/prisma/schema.prisma

@@ -53,18 +53,19 @@ model User {
   avatarImageId    String?
   disabled         Boolean          @default(false)
 
-  accounts             Account[]
-  sessions             Session[]
-  documents            Document[]
-  subscriptions        Subscription[]
-  passwordResetTokens  PasswordResetToken[]
-  ownedTeams           Team[]
-  ownedPendingTeams    TeamPending[]
-  teamMembers          TeamMember[]
-  twoFactorSecret      String?
-  twoFactorEnabled     Boolean              @default(false)
-  twoFactorBackupCodes String?
-  url                  String?              @unique
+  accounts                   Account[]
+  sessions                   Session[]
+  documents                  Document[]
+  subscriptions              Subscription[]
+  passwordResetTokens        PasswordResetToken[]
+  ownedTeams                 Team[]
+  ownedPendingTeams          TeamPending[]
+  teamMembers                TeamMember[]
+  twoFactorSecret            String?
+  twoFactorEnabled           Boolean                         @default(false)
+  twoFactorBackupCodes       String?
+  url                        String?                         @unique
+  twoFactorEmailVerification UserTwoFactorEmailVerification?
 
   profile            UserProfile?
   verificationTokens VerificationToken[]
@@ -795,3 +796,12 @@ model AvatarImage {
   team Team[]
   user User[]
 }
+
+model UserTwoFactorEmailVerification {
+  userId           Int      @id
+  verificationCode String
+  expiresAt        DateTime
+  createdAt        DateTime @default(now())
+
+  user User @relation(fields: [userId], references: [id], onDelete: Cascade)
+}

packages/trpc/server/auth-router/router.ts

@@ -1,5 +1,10 @@
 import type { RegistrationResponseJSON } from '@simplewebauthn/types';
 
+import { AppError } from '@documenso/lib/errors/app-error';
+import {
+  sendEmailVerification,
+  verifyEmailCode,
+} from '@documenso/lib/server-only/2fa/send-email-verification';
 import { createPasskey } from '@documenso/lib/server-only/auth/create-passkey';
 import { createPasskeyAuthenticationOptions } from '@documenso/lib/server-only/auth/create-passkey-authentication-options';
 import { createPasskeyRegistrationOptions } from '@documenso/lib/server-only/auth/create-passkey-registration-options';
@@ -8,6 +13,7 @@ import { deletePasskey } from '@documenso/lib/server-only/auth/delete-passkey';
 import { findPasskeys } from '@documenso/lib/server-only/auth/find-passkeys';
 import { updatePasskey } from '@documenso/lib/server-only/auth/update-passkey';
 import { nanoid } from '@documenso/lib/universal/id';
+import { prisma } from '@documenso/prisma';
 
 import { authenticatedProcedure, procedure, router } from '../trpc';
 import {
@@ -15,7 +21,9 @@ import {
   ZCreatePasskeyMutationSchema,
   ZDeletePasskeyMutationSchema,
   ZFindPasskeysQuerySchema,
+  ZSendEmailVerificationMutationSchema,
   ZUpdatePasskeyMutationSchema,
+  ZVerifyEmailCodeMutationSchema,
 } from './schema';
 
 export const authRouter = router({
@@ -98,4 +106,68 @@ export const authRouter = router({
         requestMetadata: ctx.metadata.requestMetadata,
       });
     }),
+
+  // Email verification for document signing
+  sendEmailVerification: authenticatedProcedure
+    .input(ZSendEmailVerificationMutationSchema)
+    .mutation(async ({ ctx, input }) => {
+      const { recipientId } = input;
+      const userId = ctx.user.id;
+      let email = ctx.user.email;
+
+      // If recipientId is provided, fetch that recipient's details
+      if (recipientId) {
+        const recipient = await prisma.recipient.findUnique({
+          where: {
+            id: recipientId,
+          },
+          select: {
+            email: true,
+          },
+        });
+
+        if (!recipient) {
+          throw new AppError('NOT_FOUND', {
+            message: 'Recipient not found',
+          });
+        }
+
+        email = recipient.email;
+      }
+
+      return sendEmailVerification({
+        userId,
+        email,
+      });
+    }),
+
+  verifyEmailCode: authenticatedProcedure
+    .input(ZVerifyEmailCodeMutationSchema)
+    .mutation(async ({ ctx, input }) => {
+      const { code, recipientId } = input;
+      const userId = ctx.user.id;
+
+      // If recipientId is provided, check that the user has access to it
+      if (recipientId) {
+        const recipient = await prisma.recipient.findUnique({
+          where: {
+            id: recipientId,
+          },
+          select: {
+            email: true,
+          },
+        });
+
+        if (!recipient) {
+          throw new AppError('NOT_FOUND', {
+            message: 'Recipient not found',
+          });
+        }
+      }
+
+      return verifyEmailCode({
+        userId,
+        code,
+      });
+    }),
 });

packages/trpc/server/auth-router/schema.ts

@@ -71,3 +71,18 @@ export const ZFindPasskeysQuerySchema = ZFindSearchParamsSchema.extend({
 });
 
 export type TSignUpMutationSchema = z.infer<typeof ZSignUpMutationSchema>;
+
+export const ZSendEmailVerificationMutationSchema = z.object({
+  recipientId: z.number().optional(),
+});
+
+export type TSendEmailVerificationMutationSchema = z.infer<
+  typeof ZSendEmailVerificationMutationSchema
+>;
+
+export const ZVerifyEmailCodeMutationSchema = z.object({
+  code: z.string().min(6).max(6),
+  recipientId: z.number().optional(),
+});
+
+export type TVerifyEmailCodeMutationSchema = z.infer<typeof ZVerifyEmailCodeMutationSchema>;