Implement new registration flow with email verification

.env.template

@@ -229,7 +229,8 @@
 # SIGNUPS_ALLOWED=true
 
 ## Controls if new users need to verify their email address upon registration
-## Note that setting this option to true prevents logins until the email address has been verified!
+## On new client versions, this will require the user to verify their email at signup time.
+## On older clients, it will require the user to verify their email before they can log in.
 ## The welcome email will include a verification link, and login attempts will periodically
 ## trigger another verification email to be sent.
 # SIGNUPS_VERIFY=false

src/api/core/accounts.rs

@@ -70,18 +70,31 @@ pub fn routes() -> Vec<rocket::Route> {
 #[serde(rename_all = "camelCase")]
 pub struct RegisterData {
     email: String,
+
     kdf: Option<i32>,
     kdf_iterations: Option<i32>,
     kdf_memory: Option<i32>,
     kdf_parallelism: Option<i32>,
+
+    #[serde(alias = "userSymmetricKey")]
     key: String,
+    #[serde(alias = "userAsymmetricKeys")]
     keys: Option<KeysData>,
+
     master_password_hash: String,
     master_password_hint: Option<String>,
+
     name: Option<String>,
+
     token: Option<String>,
     #[allow(dead_code)]
     organization_user_id: Option<MembershipId>,
+
+    // Used only from the register/finish endpoint
+    email_verification_token: Option<String>,
+    accept_emergency_access_id: Option<EmergencyAccessId>,
+    accept_emergency_access_invite_token: Option<String>,
+    org_invite_token: Option<String>,
 }
 
 #[derive(Debug, Deserialize)]
@@ -124,13 +137,80 @@ async fn is_email_2fa_required(member_id: Option<MembershipId>, conn: &mut DbCon
 
 #[post("/accounts/register", data = "<data>")]
 async fn register(data: Json<RegisterData>, conn: DbConn) -> JsonResult {
-    _register(data, conn).await
+    _register(data, false, conn).await
 }
 
-pub async fn _register(data: Json<RegisterData>, mut conn: DbConn) -> JsonResult {
-    let data: RegisterData = data.into_inner();
+pub async fn _register(data: Json<RegisterData>, email_verification: bool, mut conn: DbConn) -> JsonResult {
+    let mut data: RegisterData = data.into_inner();
     let email = data.email.to_lowercase();
 
+    let mut email_verified = false;
+
+    let mut pending_emergency_access = None;
+    let mut pending_org_invite = None;
+
+    // First, validate the provided verification tokens
+    if email_verification {
+        match (
+            &data.email_verification_token,
+            &data.accept_emergency_access_id,
+            &data.accept_emergency_access_invite_token,
+            &data.organization_user_id,
+            &data.org_invite_token,
+        ) {
+            // Normal user registration, when email verification is required
+            (Some(email_verification_token), None, None, None, None) => {
+                let claims = crate::auth::decode_register_verify(email_verification_token)?;
+                if claims.sub != data.email {
+                    err!("Email verification token does not match email");
+                }
+
+                // During this call we don't get the name, so extract it from the claims
+                if claims.name.is_some() {
+                    data.name = claims.name;
+                }
+                email_verified = claims.verified;
+            }
+            // Emergency access registration
+            (None, Some(accept_emergency_access_id), Some(accept_emergency_access_invite_token), None, None) => {
+                if !CONFIG.emergency_access_allowed() {
+                    err!("Emergency access is not enabled.")
+                }
+
+                let claims = crate::auth::decode_emergency_access_invite(accept_emergency_access_invite_token)?;
+
+                if claims.email != data.email {
+                    err!("Claim email does not match email")
+                }
+                if &claims.emer_id != accept_emergency_access_id {
+                    err!("Claim emer_id does not match accept_emergency_access_id")
+                }
+
+                pending_emergency_access = Some((accept_emergency_access_id, claims));
+                email_verified = true;
+            }
+            // Org invite
+            (None, None, None, Some(organization_user_id), Some(org_invite_token)) => {
+                let claims = decode_invite(org_invite_token)?;
+
+                if claims.email != data.email {
+                    err!("Claim email does not match email")
+                }
+
+                if &claims.member_id != organization_user_id {
+                    err!("Claim org_user_id does not match organization_user_id")
+                }
+
+                pending_org_invite = Some((organization_user_id, claims));
+                email_verified = true;
+            }
+
+            _ => {
+                err!("Registration is missing required parameters")
+            }
+        }
+    }
+
     // Check if the length of the username exceeds 50 characters (Same is Upstream Bitwarden)
     // This also prevents issues with very long usernames causing to large JWT's. See #2419
     if let Some(ref name) = data.name {
@@ -181,7 +261,11 @@ pub async fn _register(data: Json<RegisterData>, mut conn: DbConn) -> JsonResult
             // Order is important here; the invitation check must come first
             // because the vaultwarden admin can invite anyone, regardless
             // of other signup restrictions.
-            if Invitation::take(&email, &mut conn).await || CONFIG.is_signup_allowed(&email) {
+            if Invitation::take(&email, &mut conn).await
+                || CONFIG.is_signup_allowed(&email)
+                || pending_emergency_access.is_some()
+                || pending_org_invite.is_some()
+            {
                 User::new(email.clone())
             } else {
                 err!("Registration not allowed or user already exists")
@@ -200,6 +284,10 @@ pub async fn _register(data: Json<RegisterData>, mut conn: DbConn) -> JsonResult
         user.client_kdf_iter = client_kdf_iter;
     }
 
+    if email_verified {
+        user.verified_at = Some(Utc::now().naive_utc());
+    }
+
     user.client_kdf_memory = data.kdf_memory;
     user.client_kdf_parallelism = data.kdf_parallelism;
 

src/api/core/mod.rs

@@ -205,6 +205,9 @@ fn config() -> Json<Value> {
     feature_states.insert("key-rotation-improvements".to_string(), true);
     feature_states.insert("flexible-collections-v-1".to_string(), false);
 
+    feature_states.insert("email-verification".to_string(), true);
+    feature_states.insert("unauth-ui-refresh".to_string(), true);
+
     Json(json!({
         // Note: The clients use this version to handle backwards compatibility concerns
         // This means they expect a version that closely matches the Bitwarden server version

src/api/identity.rs

@@ -24,7 +24,7 @@ use crate::{
 };
 
 pub fn routes() -> Vec<Route> {
-    routes![login, prelogin, identity_register]
+    routes![login, prelogin, identity_register, register_verification_email, register_finish]
 }
 
 #[post("/connect/token", data = "<data>")]
@@ -714,7 +714,68 @@ async fn prelogin(data: Json<PreloginData>, conn: DbConn) -> Json<Value> {
 
 #[post("/accounts/register", data = "<data>")]
 async fn identity_register(data: Json<RegisterData>, conn: DbConn) -> JsonResult {
-    _register(data, conn).await
+    _register(data, false, conn).await
+}
+
+#[derive(Debug, Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct RegisterVerificationData {
+    email: String,
+    name: Option<String>,
+    // receiveMarketingEmails: bool,
+}
+
+#[derive(rocket::Responder)]
+enum RegisterVerificationResponse {
+    NoContent(()),
+    Token(Json<String>),
+}
+
+#[post("/accounts/register/send-verification-email", data = "<data>")]
+async fn register_verification_email(
+    data: Json<RegisterVerificationData>,
+    mut conn: DbConn,
+) -> ApiResult<RegisterVerificationResponse> {
+    let data = data.into_inner();
+
+    if !CONFIG.is_signup_allowed(&data.email) {
+        err!("Registration not allowed or user already exists")
+    }
+
+    let should_send_mail = CONFIG.mail_enabled() && CONFIG.signups_verify();
+
+    if User::find_by_mail(&data.email, &mut conn).await.is_some() {
+        if should_send_mail {
+            // There is still a timing side channel here in that the code
+            // paths that send mail take noticeably longer than ones that
+            // don't. Add a randomized sleep to mitigate this somewhat.
+            use rand::{rngs::SmallRng, Rng, SeedableRng};
+            let mut rng = SmallRng::from_os_rng();
+            let delta: i32 = 100;
+            let sleep_ms = (1_000 + rng.random_range(-delta..=delta)) as u64;
+            tokio::time::sleep(tokio::time::Duration::from_millis(sleep_ms)).await;
+        }
+        return Ok(RegisterVerificationResponse::NoContent(()));
+    }
+
+    let token_claims =
+        crate::auth::generate_register_verify_claims(data.email.clone(), data.name.clone(), should_send_mail);
+    let token = crate::auth::encode_jwt(&token_claims);
+
+    if should_send_mail {
+        mail::send_register_verify_email(&data.email, &token).await?;
+
+        Ok(RegisterVerificationResponse::NoContent(()))
+    } else {
+        // If email verification is not required, return the token directly
+        // the clients will use this token to finish the registration
+        Ok(RegisterVerificationResponse::Token(Json(token)))
+    }
+}
+
+#[post("/accounts/register/finish", data = "<data>")]
+async fn register_finish(data: Json<RegisterData>, conn: DbConn) -> JsonResult {
+    _register(data, true, conn).await
 }
 
 // https://github.com/bitwarden/jslib/blob/master/common/src/models/request/tokenRequest.ts

src/auth.rs

@@ -35,6 +35,7 @@ static JWT_ADMIN_ISSUER: Lazy<String> = Lazy::new(|| format!("{}|admin", CONFIG.
 static JWT_SEND_ISSUER: Lazy<String> = Lazy::new(|| format!("{}|send", CONFIG.domain_origin()));
 static JWT_ORG_API_KEY_ISSUER: Lazy<String> = Lazy::new(|| format!("{}|api.organization", CONFIG.domain_origin()));
 static JWT_FILE_DOWNLOAD_ISSUER: Lazy<String> = Lazy::new(|| format!("{}|file_download", CONFIG.domain_origin()));
+static JWT_REGISTER_VERIFY_ISSUER: Lazy<String> = Lazy::new(|| format!("{}|register_verify", CONFIG.domain_origin()));
 
 static PRIVATE_RSA_KEY: OnceCell<EncodingKey> = OnceCell::new();
 static PUBLIC_RSA_KEY: OnceCell<DecodingKey> = OnceCell::new();
@@ -145,6 +146,10 @@ pub fn decode_file_download(token: &str) -> Result<FileDownloadClaims, Error> {
     decode_jwt(token, JWT_FILE_DOWNLOAD_ISSUER.to_string())
 }
 
+pub fn decode_register_verify(token: &str) -> Result<RegisterVerifyClaims, Error> {
+    decode_jwt(token, JWT_REGISTER_VERIFY_ISSUER.to_string())
+}
+
 #[derive(Debug, Serialize, Deserialize)]
 pub struct LoginJwtClaims {
     // Not before
@@ -315,6 +320,33 @@ pub fn generate_file_download_claims(cipher_id: CipherId, file_id: AttachmentId)
     }
 }
 
+#[derive(Debug, Serialize, Deserialize)]
+pub struct RegisterVerifyClaims {
+    // Not before
+    pub nbf: i64,
+    // Expiration time
+    pub exp: i64,
+    // Issuer
+    pub iss: String,
+    // Subject
+    pub sub: String,
+
+    pub name: Option<String>,
+    pub verified: bool,
+}
+
+pub fn generate_register_verify_claims(email: String, name: Option<String>, verified: bool) -> RegisterVerifyClaims {
+    let time_now = Utc::now();
+    RegisterVerifyClaims {
+        nbf: time_now.timestamp(),
+        exp: (time_now + TimeDelta::try_minutes(30).unwrap()).timestamp(),
+        iss: JWT_REGISTER_VERIFY_ISSUER.to_string(),
+        sub: email,
+        name,
+        verified,
+    }
+}
+
 #[derive(Debug, Serialize, Deserialize)]
 pub struct BasicJwtClaims {
     // Not before

src/config.rs

@@ -484,7 +484,8 @@ make_config! {
         disable_icon_download:  bool,   true,   def,    false;
         /// Allow new signups |> Controls whether new users can register. Users can be invited by the vaultwarden admin even if this is disabled
         signups_allowed:        bool,   true,   def,    true;
-        /// Require email verification on signups. This will prevent logins from succeeding until the address has been verified
+        /// Require email verification on signups. On new client versions, this will require verification at signup time. On older clients,
+        /// this will prevent logins from succeeding until the address has been verified
         signups_verify:         bool,   true,   def,    false;
         /// If signups require email verification, automatically re-send verification email if it hasn't been sent for a while (in seconds)
         signups_verify_resend_time: u64, true,  def,    3_600;
@@ -1383,6 +1384,7 @@ where
     reg!("email/protected_action", ".html");
     reg!("email/pw_hint_none", ".html");
     reg!("email/pw_hint_some", ".html");
+    reg!("email/register_verify_email", ".html");
     reg!("email/send_2fa_removed_from_org", ".html");
     reg!("email/send_emergency_access_invite", ".html");
     reg!("email/send_org_invite", ".html");

src/mail.rs

@@ -201,6 +201,27 @@ pub async fn send_verify_email(address: &str, user_id: &UserId) -> EmptyResult {
     send_email(address, &subject, body_html, body_text).await
 }
 
+pub async fn send_register_verify_email(email: &str, token: &str) -> EmptyResult {
+    let mut query = url::Url::parse("https://query.builder").unwrap();
+    query.query_pairs_mut().append_pair("email", email).append_pair("token", token);
+    let query_string = match query.query() {
+        None => err!("Failed to build verify URL query parameters"),
+        Some(query) => query,
+    };
+
+    let (subject, body_html, body_text) = get_text(
+        "email/register_verify_email",
+        json!({
+            // `url.Url` would place the anchor `#` after the query parameters
+            "url": format!("{}/#/finish-signup/?{}", CONFIG.domain(), query_string),
+            "img_src": CONFIG._smtp_img_src(),
+            "email": email,
+        }),
+    )?;
+
+    send_email(email, &subject, body_html, body_text).await
+}
+
 pub async fn send_welcome(address: &str) -> EmptyResult {
     let (subject, body_html, body_text) = get_text(
         "email/welcome",

src/static/templates/email/register_verify_email.hbs

@@ -0,0 +1,8 @@
+Verify Your Email
+<!---------------->
+Verify this email address to finish creating your account by clicking the link below.
+
+Verify Email Address Now: {{{url}}}
+
+If you did not request to verify your account, you can safely ignore this email.
+{{> email/email_footer_text }}

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

@@ -0,0 +1,24 @@
+Verify Your Email
+<!---------------->
+{{> email/email_header }}
+<table width="100%" cellpadding="0" cellspacing="0" 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;">
+   <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; text-align: center;" valign="top" align="center">
+         Verify this email address to finish creating your account by clicking the link below.
+      </td>
+   </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; text-align: center;" valign="top" align="center">
+         <a href="{{{url}}}"
+            clicktracking=off target="_blank" style="color: #ffffff; text-decoration: none; text-align: center; cursor: pointer; display: inline-block; border-radius: 5px; background-color: #3c8dbc; border-color: #3c8dbc; border-style: solid; border-width: 10px 20px; margin: 0; font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; box-sizing: border-box; font-size: 16px; line-height: 25px; -webkit-font-smoothing: antialiased; -webkit-text-size-adjust: none;">
+         Verify Email Address Now
+         </a>
+      </td>
+   </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 last" 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; -webkit-text-size-adjust: none; text-align: center;" valign="top" align="center">
+         If you did not request to verify your account, you can safely ignore this email.
+      </td>
+   </tr>
+</table>
+{{> email/email_footer }}

src/static/templates/scss/vaultwarden.scss.hbs

@@ -93,12 +93,19 @@ bit-nav-logo bit-nav-item .bwi-shield {
 /**** END Static Vaultwarden Changes ****/
 /**** START Dynamic Vaultwarden Changes ****/
 {{#if signup_disabled}}
+/* From web vault 2025.1.2 and onwards, the signup button is hidden 
+  when signups are disabled as the web vault checks the /api/config endpoint.
+  Note that the clients tend to aggressively cache this endpoint, so it might
+  take a while for the change to take effect. To avoid the button appearing 
+  when it shouldn't, we'll keep this style in place for a couple of versions */
+{{#if webver "<2025.3.0"}}
 /* Hide the register link on the login screen */
 app-login form div + div + div + div + hr,
 app-login form div + div + div + div + hr + p {
   @extend %vw-hide;
 }
 {{/if}}
+{{/if}}
 
 {{#unless mail_enabled}}
 /* Hide `Email` 2FA if mail is not enabled */