Use the email token settings for Send verification codes

Reuse `EMAIL_EXPIRATION_TIME` and `EMAIL_ATTEMPTS_LIMIT`, like the email
2FA codes, instead of hardcoded values.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/auth/send.rs

@@ -171,7 +171,7 @@ impl SendTokens {
         let Some(stored) = stored else {
             return Self::expected_error("Email and OTP required", "email_and_otp_required");
         };
-        if stored.is_expired() || stored.attempts >= SendAccessOtp::MAX_ATTEMPTS {
+        if stored.is_expired() || stored.attempts_exhausted() {
             stored.delete(conn).await?;
             return Self::expected_error("Email and OTP required", "email_and_otp_required");
         }

src/db/models/send.rs

@@ -400,10 +400,6 @@ pub struct SendAccessOtp {
 }
 
 impl SendAccessOtp {
-    /// How long a code stays valid.
-    const VALIDITY_MINUTES: i64 = 5;
-    /// Wrong guesses allowed before a code is discarded.
-    pub const MAX_ATTEMPTS: i32 = 5;
     /// Minimum time before a new code can be requested, so the endpoint can't be used to spam a
     /// recipient or keep invalidating the code they are about to type.
     const RESEND_COOLDOWN_SECONDS: i64 = 60;
@@ -416,10 +412,16 @@ impl SendAccessOtp {
             code,
             attempts: 0,
             creation_date: now,
-            expiration_date: now + TimeDelta::minutes(Self::VALIDITY_MINUTES),
+            // Same settings as the email 2FA codes
+            expiration_date: now + TimeDelta::seconds(CONFIG.email_expiration_time().cast_signed()),
         }
     }
 
+    /// Wrong guesses allowed before a code is discarded.
+    pub fn attempts_exhausted(&self) -> bool {
+        u64::try_from(self.attempts).unwrap_or(u64::MAX) >= CONFIG.email_attempts_limit()
+    }
+
     pub fn is_expired(&self) -> bool {
         Utc::now().naive_utc() >= self.expiration_date
     }

src/static/templates/email/send_access_otp.hbs

@@ -2,5 +2,5 @@ Your Vaultwarden Send Verification Code
 <!---------------->
 Your email verification code is: {{token}}
 
-Use this code to view the Send that was shared with you. It expires in 5 minutes.
+Use this code to view the Send that was shared with you.
 {{> email/email_footer_text }}

src/static/templates/email/send_access_otp.html.hbs

@@ -9,7 +9,7 @@ Your Vaultwarden Send Verification Code
     </tr>
     <tr style="margin: 0; font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; box-sizing: border-box; font-size: 16px; color: #333; line-height: 25px; -webkit-font-smoothing: antialiased; -webkit-text-size-adjust: none;">
         <td class="content-block" style="font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; box-sizing: border-box; font-size: 16px; color: #333; line-height: 25px; margin: 0; -webkit-font-smoothing: antialiased; padding: 0 0 10px; -webkit-text-size-adjust: none;" valign="top">
-            Use this code to view the Send that was shared with you. It expires in 5 minutes.
+            Use this code to view the Send that was shared with you.
         </td>
     </tr>
 </table>