diff --git a/src/api/identity.rs b/src/api/identity.rs
index 0fbe77e..eb0f761 100644
--- a/src/api/identity.rs
+++ b/src/api/identity.rs
@@ -123,6 +123,7 @@ fn _password_login(data: ConnectData, conn: DbConn, ip: ClientIp) -> JsonResult
         "refresh_token": device.refresh_token,
         "Key": user.akey,
         "PrivateKey": user.private_key,
+        //"TwoFactorToken": "11122233333444555666777888999"
     });
 
     if let Some(token) = twofactor_token {
@@ -183,7 +184,7 @@ fn twofactor_auth(
         None => err_json!(_json_err_twofactor(&twofactor_ids, user_uuid, conn)?),
     };
 
-    let selected_twofactor = twofactors.into_iter().filter(|tf| tf.atype == selected_id).nth(0);
+    let selected_twofactor = twofactors.into_iter().filter(|tf| tf.atype == selected_id && tf.enabled).nth(0);
 
     use crate::api::core::two_factor as _tf;
     use crate::crypto::ct_eq;
@@ -196,6 +197,7 @@ fn twofactor_auth(
         Some(TwoFactorType::U2f) => _tf::validate_u2f_login(user_uuid, twofactor_code, conn)?,
         Some(TwoFactorType::YubiKey) => _tf::validate_yubikey_login(twofactor_code, &selected_data?)?,
         Some(TwoFactorType::Duo) => _tf::validate_duo_login(data.username.as_ref().unwrap(), twofactor_code, conn)?,
+        Some(TwoFactorType::Email) => _tf::validate_totp_code_str(twofactor_code, &selected_data?)?,
 
         Some(TwoFactorType::Remember) => {
             match device.twofactor_remember {
@@ -286,6 +288,13 @@ fn _json_err_twofactor(providers: &[i32], user_uuid: &str, conn: &DbConn) -> Api
                 })
             }
 
+            Some(tf_type @ TwoFactorType::Email) => {
+                let twofactor = match TwoFactor::find_by_user_and_type(user_uuid, tf_type as i32, &conn) {
+                    Some(tf) => tf,
+                    None => err!("No twofactor email registered"),
+                };
+            }
+
             _ => {}
         }
     }
diff --git a/src/api/two_factor.rs b/src/api/two_factor.rs
new file mode 100644
index 0000000..70f4306
--- /dev/null
+++ b/src/api/two_factor.rs
@@ -0,0 +1,1208 @@
+use data_encoding::{BASE32, BASE64};
+use rocket_contrib::json::Json;
+use serde_json;
+use serde_json::Value;
+
+use crate::api::{ApiResult, EmptyResult, JsonResult, JsonUpcase, NumberOrString, PasswordData};
+use crate::auth::Headers;
+use crate::{crypto, mail};
+use crate::db::{
+    models::{TwoFactor, TwoFactorType, User},
+    DbConn,
+};
+use crate::error::{Error, MapResult};
+
+use rocket::Route;
+
+pub fn routes() -> Vec<Route> {
+    routes![
+        get_twofactor,
+        get_recover,
+        recover,
+        disable_twofactor,
+        disable_twofactor_put,
+        generate_authenticator,
+        activate_authenticator,
+        activate_authenticator_put,
+        generate_u2f,
+        generate_u2f_challenge,
+        activate_u2f,
+        activate_u2f_put,
+        generate_yubikey,
+        activate_yubikey,
+        activate_yubikey_put,
+        get_duo,
+        activate_duo,
+        activate_duo_put,
+        get_email,
+        send_email_login,
+        send_email,
+        email,
+    ]
+}
+
+#[get("/two-factor")]
+fn get_twofactor(headers: Headers, conn: DbConn) -> JsonResult {
+    let twofactors = TwoFactor::find_by_user(&headers.user.uuid, &conn);
+    let twofactors_json: Vec<Value> = twofactors.iter().map(TwoFactor::to_json_list).collect();
+
+    Ok(Json(json!({
+        "Data": twofactors_json,
+        "Object": "list",
+        "ContinuationToken": null,
+    })))
+}
+
+#[post("/two-factor/get-recover", data = "<data>")]
+fn get_recover(data: JsonUpcase<PasswordData>, headers: Headers) -> JsonResult {
+    let data: PasswordData = data.into_inner().data;
+    let user = headers.user;
+
+    if !user.check_valid_password(&data.MasterPasswordHash) {
+        err!("Invalid password");
+    }
+
+    Ok(Json(json!({
+        "Code": user.totp_recover,
+        "Object": "twoFactorRecover"
+    })))
+}
+
+#[derive(Deserialize)]
+#[allow(non_snake_case)]
+struct RecoverTwoFactor {
+    MasterPasswordHash: String,
+    Email: String,
+    RecoveryCode: String,
+}
+
+#[post("/two-factor/recover", data = "<data>")]
+fn recover(data: JsonUpcase<RecoverTwoFactor>, conn: DbConn) -> JsonResult {
+    let data: RecoverTwoFactor = data.into_inner().data;
+
+    use crate::db::models::User;
+
+    // Get the user
+    let mut user = match User::find_by_mail(&data.Email, &conn) {
+        Some(user) => user,
+        None => err!("Username or password is incorrect. Try again."),
+    };
+
+    // Check password
+    if !user.check_valid_password(&data.MasterPasswordHash) {
+        err!("Username or password is incorrect. Try again.")
+    }
+
+    // Check if recovery code is correct
+    if !user.check_valid_recovery_code(&data.RecoveryCode) {
+        err!("Recovery code is incorrect. Try again.")
+    }
+
+    // Remove all twofactors from the user
+    for twofactor in TwoFactor::find_by_user(&user.uuid, &conn) {
+        twofactor.delete(&conn)?;
+    }
+
+    // Remove the recovery code, not needed without twofactors
+    user.totp_recover = None;
+    user.save(&conn)?;
+    Ok(Json(json!({})))
+}
+
+fn _generate_recover_code(user: &mut User, conn: &DbConn) {
+    if user.totp_recover.is_none() {
+        let totp_recover = BASE32.encode(&crypto::get_random(vec![0u8; 20]));
+        user.totp_recover = Some(totp_recover);
+        user.save(conn).ok();
+    }
+}
+
+#[derive(Deserialize)]
+#[allow(non_snake_case)]
+struct DisableTwoFactorData {
+    MasterPasswordHash: String,
+    Type: NumberOrString,
+}
+
+#[post("/two-factor/disable", data = "<data>")]
+fn disable_twofactor(data: JsonUpcase<DisableTwoFactorData>, headers: Headers, conn: DbConn) -> JsonResult {
+    let data: DisableTwoFactorData = data.into_inner().data;
+    let password_hash = data.MasterPasswordHash;
+    let user = headers.user;
+
+    if !user.check_valid_password(&password_hash) {
+        err!("Invalid password");
+    }
+
+    let type_ = data.Type.into_i32()?;
+
+    if let Some(twofactor) = TwoFactor::find_by_user_and_type(&user.uuid, type_, &conn) {
+        twofactor.delete(&conn)?;
+    }
+
+    Ok(Json(json!({
+        "Enabled": false,
+        "Type": type_,
+        "Object": "twoFactorProvider"
+    })))
+}
+
+#[put("/two-factor/disable", data = "<data>")]
+fn disable_twofactor_put(data: JsonUpcase<DisableTwoFactorData>, headers: Headers, conn: DbConn) -> JsonResult {
+    disable_twofactor(data, headers, conn)
+}
+
+#[post("/two-factor/get-authenticator", data = "<data>")]
+fn generate_authenticator(data: JsonUpcase<PasswordData>, headers: Headers, conn: DbConn) -> JsonResult {
+    let data: PasswordData = data.into_inner().data;
+    let user = headers.user;
+
+    if !user.check_valid_password(&data.MasterPasswordHash) {
+        err!("Invalid password");
+    }
+
+    let type_ = TwoFactorType::Authenticator as i32;
+    let twofactor = TwoFactor::find_by_user_and_type(&user.uuid, type_, &conn);
+
+    let (enabled, key) = match twofactor {
+        Some(tf) => (true, tf.data),
+        _ => (false, BASE32.encode(&crypto::get_random(vec![0u8; 20]))),
+    };
+
+    Ok(Json(json!({
+        "Enabled": enabled,
+        "Key": key,
+        "Object": "twoFactorAuthenticator"
+    })))
+}
+
+#[derive(Deserialize, Debug)]
+#[allow(non_snake_case)]
+struct EnableAuthenticatorData {
+    MasterPasswordHash: String,
+    Key: String,
+    Token: NumberOrString,
+}
+
+fn validate_decode_key(key: &str) -> Result<Vec<u8>, crate::error::Error> {
+    // Validate key as base32 and 20 bytes length
+    let decoded_key: Vec<u8> = match BASE32.decode(key.as_bytes()) {
+        Ok(decoded) => decoded,
+        _ => err!("Invalid totp secret"),
+    };
+
+    if decoded_key.len() != 20 {
+        err!("Invalid key length")
+    }
+
+    Ok(decoded_key)
+}
+
+#[post("/two-factor/authenticator", data = "<data>")]
+fn activate_authenticator(data: JsonUpcase<EnableAuthenticatorData>, headers: Headers, conn: DbConn) -> JsonResult {
+    let data: EnableAuthenticatorData = data.into_inner().data;
+    let password_hash = data.MasterPasswordHash;
+    let key = data.Key;
+    let token = data.Token.into_i32()? as u64;
+
+    let mut user = headers.user;
+
+    if !user.check_valid_password(&password_hash) {
+        err!("Invalid password");
+    }
+
+    // Validate key as base32 and 20 bytes length
+    let decoded_key = validate_decode_key(&key)?;
+
+    let type_ = TwoFactorType::Authenticator;
+    let twofactor = TwoFactor::new(user.uuid.clone(), type_, key.to_uppercase());
+
+    // Validate the token provided with the key
+    validate_totp_code(token, &twofactor.data)?;
+
+    _generate_recover_code(&mut user, &conn);
+    twofactor.save(&conn)?;
+
+    Ok(Json(json!({
+        "Enabled": true,
+        "Key": key,
+        "Object": "twoFactorAuthenticator"
+    })))
+}
+
+#[put("/two-factor/authenticator", data = "<data>")]
+fn activate_authenticator_put(data: JsonUpcase<EnableAuthenticatorData>, headers: Headers, conn: DbConn) -> JsonResult {
+    activate_authenticator(data, headers, conn)
+}
+
+pub fn validate_totp_code_str(totp_code: &str, secret: &str) -> EmptyResult {
+    let totp_code: u64 = match totp_code.parse() {
+        Ok(code) => code,
+        _ => err!("TOTP code is not a number"),
+    };
+
+    validate_totp_code(totp_code, secret)
+}
+
+pub fn validate_totp_code(totp_code: u64, secret: &str) -> EmptyResult {
+    use oath::{totp_raw_now, HashType};
+
+    let decoded_secret = match BASE32.decode(secret.as_bytes()) {
+        Ok(s) => s,
+        Err(_) => err!("Invalid TOTP secret"),
+    };
+
+    let generated = totp_raw_now(&decoded_secret, 6, 0, 30, &HashType::SHA1);
+    if generated != totp_code {
+        err!("Invalid TOTP code");
+    }
+
+    Ok(())
+}
+
+use u2f::messages::{RegisterResponse, SignResponse, U2fSignRequest};
+use u2f::protocol::{Challenge, U2f};
+use u2f::register::Registration;
+
+use crate::CONFIG;
+
+const U2F_VERSION: &str = "U2F_V2";
+
+lazy_static! {
+    static ref APP_ID: String = format!("{}/app-id.json", &CONFIG.domain());
+    static ref U2F: U2f = U2f::new(APP_ID.clone());
+}
+
+#[post("/two-factor/get-u2f", data = "<data>")]
+fn generate_u2f(data: JsonUpcase<PasswordData>, headers: Headers, conn: DbConn) -> JsonResult {
+    if !CONFIG.domain_set() {
+        err!("`DOMAIN` environment variable is not set. U2F disabled")
+    }
+    let data: PasswordData = data.into_inner().data;
+
+    if !headers.user.check_valid_password(&data.MasterPasswordHash) {
+        err!("Invalid password");
+    }
+
+    let (enabled, keys) = get_u2f_registrations(&headers.user.uuid, &conn)?;
+    let keys_json: Vec<Value> = keys.iter().map(U2FRegistration::to_json).collect();
+
+    Ok(Json(json!({
+        "Enabled": enabled,
+        "Keys": keys_json,
+        "Object": "twoFactorU2f"
+    })))
+}
+
+#[post("/two-factor/get-u2f-challenge", data = "<data>")]
+fn generate_u2f_challenge(data: JsonUpcase<PasswordData>, headers: Headers, conn: DbConn) -> JsonResult {
+    let data: PasswordData = data.into_inner().data;
+
+    if !headers.user.check_valid_password(&data.MasterPasswordHash) {
+        err!("Invalid password");
+    }
+
+    let _type = TwoFactorType::U2fRegisterChallenge;
+    let challenge = _create_u2f_challenge(&headers.user.uuid, _type, &conn).challenge;
+
+    Ok(Json(json!({
+        "UserId": headers.user.uuid,
+        "AppId": APP_ID.to_string(),
+        "Challenge": challenge,
+        "Version": U2F_VERSION,
+    })))
+}
+
+#[derive(Deserialize, Debug)]
+#[allow(non_snake_case)]
+struct EnableU2FData {
+    Id: NumberOrString, // 1..5
+    Name: String,
+    MasterPasswordHash: String,
+    DeviceResponse: String,
+}
+
+// This struct is referenced from the U2F lib
+// because it doesn't implement Deserialize
+#[derive(Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+#[serde(remote = "Registration")]
+struct RegistrationDef {
+    key_handle: Vec<u8>,
+    pub_key: Vec<u8>,
+    attestation_cert: Option<Vec<u8>>,
+}
+
+#[derive(Serialize, Deserialize)]
+struct U2FRegistration {
+    id: i32,
+    name: String,
+    #[serde(with = "RegistrationDef")]
+    reg: Registration,
+    counter: u32,
+    compromised: bool,
+}
+
+impl U2FRegistration {
+    fn to_json(&self) -> Value {
+        json!({
+            "Id": self.id,
+            "Name": self.name,
+            "Compromised": self.compromised,
+        })
+    }
+}
+
+// This struct is copied from the U2F lib
+// to add an optional error code
+#[derive(Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct RegisterResponseCopy {
+    pub registration_data: String,
+    pub version: String,
+    pub client_data: String,
+
+    pub error_code: Option<NumberOrString>,
+}
+
+impl Into<RegisterResponse> for RegisterResponseCopy {
+    fn into(self) -> RegisterResponse {
+        RegisterResponse {
+            registration_data: self.registration_data,
+            version: self.version,
+            client_data: self.client_data,
+        }
+    }
+}
+
+#[post("/two-factor/u2f", data = "<data>")]
+fn activate_u2f(data: JsonUpcase<EnableU2FData>, headers: Headers, conn: DbConn) -> JsonResult {
+    let data: EnableU2FData = data.into_inner().data;
+    let mut user = headers.user;
+
+    if !user.check_valid_password(&data.MasterPasswordHash) {
+        err!("Invalid password");
+    }
+
+    let tf_type = TwoFactorType::U2fRegisterChallenge as i32;
+    let tf_challenge = match TwoFactor::find_by_user_and_type(&user.uuid, tf_type, &conn) {
+        Some(c) => c,
+        None => err!("Can't recover challenge"),
+    };
+
+    let challenge: Challenge = serde_json::from_str(&tf_challenge.data)?;
+    tf_challenge.delete(&conn)?;
+
+    let response: RegisterResponseCopy = serde_json::from_str(&data.DeviceResponse)?;
+
+    let error_code = response
+        .error_code
+        .clone()
+        .map_or("0".into(), NumberOrString::into_string);
+
+    if error_code != "0" {
+        err!("Error registering U2F token")
+    }
+
+    let registration = U2F.register_response(challenge.clone(), response.into())?;
+    let full_registration = U2FRegistration {
+        id: data.Id.into_i32()?,
+        name: data.Name,
+        reg: registration,
+        compromised: false,
+        counter: 0,
+    };
+
+    let mut regs = get_u2f_registrations(&user.uuid, &conn)?.1;
+
+    // TODO: Check that there is no repeat Id
+    regs.push(full_registration);
+    save_u2f_registrations(&user.uuid, &regs, &conn)?;
+
+    _generate_recover_code(&mut user, &conn);
+
+    let keys_json: Vec<Value> = regs.iter().map(U2FRegistration::to_json).collect();
+    Ok(Json(json!({
+        "Enabled": true,
+        "Keys": keys_json,
+        "Object": "twoFactorU2f"
+    })))
+}
+
+#[put("/two-factor/u2f", data = "<data>")]
+fn activate_u2f_put(data: JsonUpcase<EnableU2FData>, headers: Headers, conn: DbConn) -> JsonResult {
+    activate_u2f(data, headers, conn)
+}
+
+fn _create_u2f_challenge(user_uuid: &str, type_: TwoFactorType, conn: &DbConn) -> Challenge {
+    let challenge = U2F.generate_challenge().unwrap();
+
+    TwoFactor::new(user_uuid.into(), type_, serde_json::to_string(&challenge).unwrap())
+        .save(conn)
+        .expect("Error saving challenge");
+
+    challenge
+}
+
+fn save_u2f_registrations(user_uuid: &str, regs: &[U2FRegistration], conn: &DbConn) -> EmptyResult {
+    TwoFactor::new(user_uuid.into(), TwoFactorType::U2f, serde_json::to_string(regs)?).save(&conn)
+}
+
+fn get_u2f_registrations(user_uuid: &str, conn: &DbConn) -> Result<(bool, Vec<U2FRegistration>), Error> {
+    let type_ = TwoFactorType::U2f as i32;
+    let (enabled, regs) = match TwoFactor::find_by_user_and_type(user_uuid, type_, conn) {
+        Some(tf) => (tf.enabled, tf.data),
+        None => return Ok((false, Vec::new())), // If no data, return empty list
+    };
+
+    let data = match serde_json::from_str(&regs) {
+        Ok(d) => d,
+        Err(_) => {
+            // If error, try old format
+            let mut old_regs = _old_parse_registrations(&regs);
+
+            if old_regs.len() != 1 {
+                err!("The old U2F format only allows one device")
+            }
+
+            // Convert to new format
+            let new_regs = vec![U2FRegistration {
+                id: 1,
+                name: "Unnamed U2F key".into(),
+                reg: old_regs.remove(0),
+                compromised: false,
+                counter: 0,
+            }];
+
+            // Save new format
+            save_u2f_registrations(user_uuid, &new_regs, &conn)?;
+
+            new_regs
+        }
+    };
+
+    Ok((enabled, data))
+}
+
+fn _old_parse_registrations(registations: &str) -> Vec<Registration> {
+    #[derive(Deserialize)]
+    struct Helper(#[serde(with = "RegistrationDef")] Registration);
+
+    let regs: Vec<Value> = serde_json::from_str(registations).expect("Can't parse Registration data");
+
+    regs.into_iter()
+        .map(|r| serde_json::from_value(r).unwrap())
+        .map(|Helper(r)| r)
+        .collect()
+}
+
+pub fn generate_u2f_login(user_uuid: &str, conn: &DbConn) -> ApiResult<U2fSignRequest> {
+    let challenge = _create_u2f_challenge(user_uuid, TwoFactorType::U2fLoginChallenge, conn);
+
+    let registrations: Vec<_> = get_u2f_registrations(user_uuid, conn)?
+        .1
+        .into_iter()
+        .map(|r| r.reg)
+        .collect();
+
+    if registrations.is_empty() {
+        err!("No U2F devices registered")
+    }
+
+    Ok(U2F.sign_request(challenge, registrations))
+}
+
+pub fn validate_u2f_login(user_uuid: &str, response: &str, conn: &DbConn) -> EmptyResult {
+    let challenge_type = TwoFactorType::U2fLoginChallenge as i32;
+    let tf_challenge = TwoFactor::find_by_user_and_type(user_uuid, challenge_type, &conn);
+
+    let challenge = match tf_challenge {
+        Some(tf_challenge) => {
+            let challenge: Challenge = serde_json::from_str(&tf_challenge.data)?;
+            tf_challenge.delete(&conn)?;
+            challenge
+        }
+        None => err!("Can't recover login challenge"),
+    };
+    let response: SignResponse = serde_json::from_str(response)?;
+    let mut registrations = get_u2f_registrations(user_uuid, conn)?.1;
+    if registrations.is_empty() {
+        err!("No U2F devices registered")
+    }
+
+    for reg in &mut registrations {
+        let response = U2F.sign_response(challenge.clone(), reg.reg.clone(), response.clone(), reg.counter);
+        match response {
+            Ok(new_counter) => {
+                reg.counter = new_counter;
+                save_u2f_registrations(user_uuid, &registrations, &conn)?;
+
+                return Ok(());
+            }
+            Err(u2f::u2ferror::U2fError::CounterTooLow) => {
+                reg.compromised = true;
+                save_u2f_registrations(user_uuid, &registrations, &conn)?;
+
+                err!("This device might be compromised!");
+            }
+            Err(e) => {
+                warn!("E {:#}", e);
+                // break;
+            }
+        }
+    }
+    err!("error verifying response")
+}
+
+#[derive(Deserialize, Debug)]
+#[allow(non_snake_case)]
+struct EnableYubikeyData {
+    MasterPasswordHash: String,
+    Key1: Option<String>,
+    Key2: Option<String>,
+    Key3: Option<String>,
+    Key4: Option<String>,
+    Key5: Option<String>,
+    Nfc: bool,
+}
+
+#[derive(Deserialize, Serialize, Debug)]
+#[allow(non_snake_case)]
+pub struct YubikeyMetadata {
+    Keys: Vec<String>,
+    pub Nfc: bool,
+}
+
+use yubico::config::Config;
+use yubico::verify;
+
+fn parse_yubikeys(data: &EnableYubikeyData) -> Vec<String> {
+    let data_keys = [&data.Key1, &data.Key2, &data.Key3, &data.Key4, &data.Key5];
+
+    data_keys.iter().filter_map(|e| e.as_ref().cloned()).collect()
+}
+
+fn jsonify_yubikeys(yubikeys: Vec<String>) -> serde_json::Value {
+    let mut result = json!({});
+
+    for (i, key) in yubikeys.into_iter().enumerate() {
+        result[format!("Key{}", i + 1)] = Value::String(key);
+    }
+
+    result
+}
+
+fn get_yubico_credentials() -> Result<(String, String), Error> {
+    match (CONFIG.yubico_client_id(), CONFIG.yubico_secret_key()) {
+        (Some(id), Some(secret)) => Ok((id, secret)),
+        _ => err!("`YUBICO_CLIENT_ID` or `YUBICO_SECRET_KEY` environment variable is not set. Yubikey OTP Disabled"),
+    }
+}
+
+fn verify_yubikey_otp(otp: String) -> EmptyResult {
+    let (yubico_id, yubico_secret) = get_yubico_credentials()?;
+
+    let config = Config::default().set_client_id(yubico_id).set_key(yubico_secret);
+
+    match CONFIG.yubico_server() {
+        Some(server) => verify(otp, config.set_api_hosts(vec![server])),
+        None => verify(otp, config),
+    }
+    .map_res("Failed to verify OTP")
+    .and(Ok(()))
+}
+
+#[post("/two-factor/get-yubikey", data = "<data>")]
+fn generate_yubikey(data: JsonUpcase<PasswordData>, headers: Headers, conn: DbConn) -> JsonResult {
+    // Make sure the credentials are set
+    get_yubico_credentials()?;
+
+    let data: PasswordData = data.into_inner().data;
+    let user = headers.user;
+
+    if !user.check_valid_password(&data.MasterPasswordHash) {
+        err!("Invalid password");
+    }
+
+    let user_uuid = &user.uuid;
+    let yubikey_type = TwoFactorType::YubiKey as i32;
+
+    let r = TwoFactor::find_by_user_and_type(user_uuid, yubikey_type, &conn);
+
+    if let Some(r) = r {
+        let yubikey_metadata: YubikeyMetadata = serde_json::from_str(&r.data)?;
+
+        let mut result = jsonify_yubikeys(yubikey_metadata.Keys);
+
+        result["Enabled"] = Value::Bool(true);
+        result["Nfc"] = Value::Bool(yubikey_metadata.Nfc);
+        result["Object"] = Value::String("twoFactorU2f".to_owned());
+
+        Ok(Json(result))
+    } else {
+        Ok(Json(json!({
+            "Enabled": false,
+            "Object": "twoFactorU2f",
+        })))
+    }
+}
+
+#[post("/two-factor/yubikey", data = "<data>")]
+fn activate_yubikey(data: JsonUpcase<EnableYubikeyData>, headers: Headers, conn: DbConn) -> JsonResult {
+    let data: EnableYubikeyData = data.into_inner().data;
+    let mut user = headers.user;
+
+    if !user.check_valid_password(&data.MasterPasswordHash) {
+        err!("Invalid password");
+    }
+
+    // Check if we already have some data
+    let mut yubikey_data = match TwoFactor::find_by_user_and_type(&user.uuid, TwoFactorType::YubiKey as i32, &conn) {
+        Some(data) => data,
+        None => TwoFactor::new(user.uuid.clone(), TwoFactorType::YubiKey, String::new()),
+    };
+
+    let yubikeys = parse_yubikeys(&data);
+
+    if yubikeys.is_empty() {
+        return Ok(Json(json!({
+            "Enabled": false,
+            "Object": "twoFactorU2f",
+        })));
+    }
+
+    // Ensure they are valid OTPs
+    for yubikey in &yubikeys {
+        if yubikey.len() == 12 {
+            // YubiKey ID
+            continue;
+        }
+
+        verify_yubikey_otp(yubikey.to_owned()).map_res("Invalid Yubikey OTP provided")?;
+    }
+
+    let yubikey_ids: Vec<String> = yubikeys.into_iter().map(|x| (&x[..12]).to_owned()).collect();
+
+    let yubikey_metadata = YubikeyMetadata {
+        Keys: yubikey_ids,
+        Nfc: data.Nfc,
+    };
+
+    yubikey_data.data = serde_json::to_string(&yubikey_metadata).unwrap();
+    yubikey_data.save(&conn)?;
+
+    _generate_recover_code(&mut user, &conn);
+
+    let mut result = jsonify_yubikeys(yubikey_metadata.Keys);
+
+    result["Enabled"] = Value::Bool(true);
+    result["Nfc"] = Value::Bool(yubikey_metadata.Nfc);
+    result["Object"] = Value::String("twoFactorU2f".to_owned());
+
+    Ok(Json(result))
+}
+
+#[put("/two-factor/yubikey", data = "<data>")]
+fn activate_yubikey_put(data: JsonUpcase<EnableYubikeyData>, headers: Headers, conn: DbConn) -> JsonResult {
+    activate_yubikey(data, headers, conn)
+}
+
+pub fn validate_yubikey_login(response: &str, twofactor_data: &str) -> EmptyResult {
+    if response.len() != 44 {
+        err!("Invalid Yubikey OTP length");
+    }
+
+    let yubikey_metadata: YubikeyMetadata = serde_json::from_str(twofactor_data).expect("Can't parse Yubikey Metadata");
+    let response_id = &response[..12];
+
+    if !yubikey_metadata.Keys.contains(&response_id.to_owned()) {
+        err!("Given Yubikey is not registered");
+    }
+
+    let result = verify_yubikey_otp(response.to_owned());
+
+    match result {
+        Ok(_answer) => Ok(()),
+        Err(_e) => err!("Failed to verify Yubikey against OTP server"),
+    }
+}
+
+#[derive(Serialize, Deserialize)]
+struct DuoData {
+    host: String,
+    ik: String,
+    sk: String,
+}
+
+impl DuoData {
+    fn global() -> Option<Self> {
+        match CONFIG.duo_host() {
+            Some(host) => Some(Self {
+                host,
+                ik: CONFIG.duo_ikey().unwrap(),
+                sk: CONFIG.duo_skey().unwrap(),
+            }),
+            None => None,
+        }
+    }
+    fn msg(s: &str) -> Self {
+        Self {
+            host: s.into(),
+            ik: s.into(),
+            sk: s.into(),
+        }
+    }
+    fn secret() -> Self {
+        Self::msg("<global_secret>")
+    }
+    fn obscure(self) -> Self {
+        let mut host = self.host;
+        let mut ik = self.ik;
+        let mut sk = self.sk;
+
+        let digits = 4;
+        let replaced = "************";
+
+        host.replace_range(digits.., replaced);
+        ik.replace_range(digits.., replaced);
+        sk.replace_range(digits.., replaced);
+
+        Self { host, ik, sk }
+    }
+}
+
+enum DuoStatus {
+    Global(DuoData), // Using the global duo config
+    User(DuoData),   // Using the user's config
+    Disabled(bool),  // True if there is a global setting
+}
+
+impl DuoStatus {
+    fn data(self) -> Option<DuoData> {
+        match self {
+            DuoStatus::Global(data) => Some(data),
+            DuoStatus::User(data) => Some(data),
+            DuoStatus::Disabled(_) => None,
+        }
+    }
+}
+const DISABLED_MESSAGE_DEFAULT: &str = "<To use the global Duo keys, please leave these fields untouched>";
+
+#[post("/two-factor/get-duo", data = "<data>")]
+fn get_duo(data: JsonUpcase<PasswordData>, headers: Headers, conn: DbConn) -> JsonResult {
+    let data: PasswordData = data.into_inner().data;
+
+    if !headers.user.check_valid_password(&data.MasterPasswordHash) {
+        err!("Invalid password");
+    }
+
+    let data = get_user_duo_data(&headers.user.uuid, &conn);
+
+    let (enabled, data) = match data {
+        DuoStatus::Global(_) => (true, Some(DuoData::secret())),
+        DuoStatus::User(data) => (true, Some(data.obscure())),
+        DuoStatus::Disabled(true) => (false, Some(DuoData::msg(DISABLED_MESSAGE_DEFAULT))),
+        DuoStatus::Disabled(false) => (false, None),
+    };
+
+    let json = if let Some(data) = data {
+        json!({
+            "Enabled": enabled,
+            "Host": data.host,
+            "SecretKey": data.sk,
+            "IntegrationKey": data.ik,
+            "Object": "twoFactorDuo"
+        })
+    } else {
+        json!({
+            "Enabled": enabled,
+            "Object": "twoFactorDuo"
+        })
+    };
+
+    Ok(Json(json))
+}
+
+#[derive(Deserialize)]
+#[allow(non_snake_case, dead_code)]
+struct EnableDuoData {
+    MasterPasswordHash: String,
+    Host: String,
+    SecretKey: String,
+    IntegrationKey: String,
+}
+
+impl From<EnableDuoData> for DuoData {
+    fn from(d: EnableDuoData) -> Self {
+        Self {
+            host: d.Host,
+            ik: d.IntegrationKey,
+            sk: d.SecretKey,
+        }
+    }
+}
+
+fn check_duo_fields_custom(data: &EnableDuoData) -> bool {
+    fn empty_or_default(s: &str) -> bool {
+        let st = s.trim();
+        st.is_empty() || s == DISABLED_MESSAGE_DEFAULT
+    }
+
+    !empty_or_default(&data.Host) && !empty_or_default(&data.SecretKey) && !empty_or_default(&data.IntegrationKey)
+}
+
+#[post("/two-factor/duo", data = "<data>")]
+fn activate_duo(data: JsonUpcase<EnableDuoData>, headers: Headers, conn: DbConn) -> JsonResult {
+    let data: EnableDuoData = data.into_inner().data;
+
+    if !headers.user.check_valid_password(&data.MasterPasswordHash) {
+        err!("Invalid password");
+    }
+
+    let (data, data_str) = if check_duo_fields_custom(&data) {
+        let data_req: DuoData = data.into();
+        let data_str = serde_json::to_string(&data_req)?;
+        duo_api_request("GET", "/auth/v2/check", "", &data_req).map_res("Failed to validate Duo credentials")?;
+        (data_req.obscure(), data_str)
+    } else {
+        (DuoData::secret(), String::new())
+    };
+
+    let type_ = TwoFactorType::Duo;
+    let twofactor = TwoFactor::new(headers.user.uuid.clone(), type_, data_str);
+    twofactor.save(&conn)?;
+
+    Ok(Json(json!({
+        "Enabled": true,
+        "Host": data.host,
+        "SecretKey": data.sk,
+        "IntegrationKey": data.ik,
+        "Object": "twoFactorDuo"
+    })))
+}
+
+#[put("/two-factor/duo", data = "<data>")]
+fn activate_duo_put(data: JsonUpcase<EnableDuoData>, headers: Headers, conn: DbConn) -> JsonResult {
+    activate_duo(data, headers, conn)
+}
+
+fn duo_api_request(method: &str, path: &str, params: &str, data: &DuoData) -> EmptyResult {
+    const AGENT: &str = "bitwarden_rs:Duo/1.0 (Rust)";
+
+    use reqwest::{header::*, Client, Method};
+    use std::str::FromStr;
+
+    let url = format!("https://{}{}", &data.host, path);
+    let date = Utc::now().to_rfc2822();
+    let username = &data.ik;
+    let fields = [&date, method, &data.host, path, params];
+    let password = crypto::hmac_sign(&data.sk, &fields.join("\n"));
+
+    let m = Method::from_str(method).unwrap_or_default();
+
+    Client::new()
+        .request(m, &url)
+        .basic_auth(username, Some(password))
+        .header(USER_AGENT, AGENT)
+        .header(DATE, date)
+        .send()?
+        .error_for_status()?;
+
+    Ok(())
+}
+
+const DUO_EXPIRE: i64 = 300;
+const APP_EXPIRE: i64 = 3600;
+
+const AUTH_PREFIX: &str = "AUTH";
+const DUO_PREFIX: &str = "TX";
+const APP_PREFIX: &str = "APP";
+
+use chrono::Utc;
+use oath::{totp_raw_now, HashType};
+
+fn get_user_duo_data(uuid: &str, conn: &DbConn) -> DuoStatus {
+    let type_ = TwoFactorType::Duo as i32;
+
+    // If the user doesn't have an entry, disabled
+    let twofactor = match TwoFactor::find_by_user_and_type(uuid, type_, &conn) {
+        Some(t) => t,
+        None => return DuoStatus::Disabled(DuoData::global().is_some()),
+    };
+
+    // If the user has the required values, we use those
+    if let Ok(data) = serde_json::from_str(&twofactor.data) {
+        return DuoStatus::User(data);
+    }
+
+    // Otherwise, we try to use the globals
+    if let Some(global) = DuoData::global() {
+        return DuoStatus::Global(global);
+    }
+
+    // If there are no globals configured, just disable it
+    DuoStatus::Disabled(false)
+}
+
+// let (ik, sk, ak, host) = get_duo_keys();
+fn get_duo_keys_email(email: &str, conn: &DbConn) -> ApiResult<(String, String, String, String)> {
+    let data = User::find_by_mail(email, &conn)
+        .and_then(|u| get_user_duo_data(&u.uuid, &conn).data())
+        .or_else(DuoData::global)
+        .map_res("Can't fetch Duo keys")?;
+
+    Ok((data.ik, data.sk, CONFIG.get_duo_akey(), data.host))
+}
+
+pub fn generate_duo_signature(email: &str, conn: &DbConn) -> ApiResult<(String, String)> {
+    let now = Utc::now().timestamp();
+
+    let (ik, sk, ak, host) = get_duo_keys_email(email, conn)?;
+
+    let duo_sign = sign_duo_values(&sk, email, &ik, DUO_PREFIX, now + DUO_EXPIRE);
+    let app_sign = sign_duo_values(&ak, email, &ik, APP_PREFIX, now + APP_EXPIRE);
+
+    Ok((format!("{}:{}", duo_sign, app_sign), host))
+}
+
+fn sign_duo_values(key: &str, email: &str, ikey: &str, prefix: &str, expire: i64) -> String {
+    let val = format!("{}|{}|{}", email, ikey, expire);
+    let cookie = format!("{}|{}", prefix, BASE64.encode(val.as_bytes()));
+
+    format!("{}|{}", cookie, crypto::hmac_sign(key, &cookie))
+}
+
+
+
+pub fn validate_email_login(twofactor_code: &str, secret: &str) -> EmptyResult {
+
+    Ok(())
+}
+
+pub fn validate_duo_login(email: &str, response: &str, conn: &DbConn) -> EmptyResult {
+    let split: Vec<&str> = response.split(':').collect();
+    if split.len() != 2 {
+        err!("Invalid response length");
+    }
+
+    let auth_sig = split[0];
+    let app_sig = split[1];
+
+    let now = Utc::now().timestamp();
+
+    let (ik, sk, ak, _host) = get_duo_keys_email(email, conn)?;
+
+    let auth_user = parse_duo_values(&sk, auth_sig, &ik, AUTH_PREFIX, now)?;
+    let app_user = parse_duo_values(&ak, app_sig, &ik, APP_PREFIX, now)?;
+
+    if !crypto::ct_eq(&auth_user, app_user) || !crypto::ct_eq(&auth_user, email) {
+        err!("Error validating duo authentication")
+    }
+
+    Ok(())
+}
+
+fn parse_duo_values(key: &str, val: &str, ikey: &str, prefix: &str, time: i64) -> ApiResult<String> {
+    let split: Vec<&str> = val.split('|').collect();
+    if split.len() != 3 {
+        err!("Invalid value length")
+    }
+
+    let u_prefix = split[0];
+    let u_b64 = split[1];
+    let u_sig = split[2];
+
+    let sig = crypto::hmac_sign(key, &format!("{}|{}", u_prefix, u_b64));
+
+    if !crypto::ct_eq(crypto::hmac_sign(key, &sig), crypto::hmac_sign(key, u_sig)) {
+        err!("Duo signatures don't match")
+    }
+
+    if u_prefix != prefix {
+        err!("Prefixes don't match")
+    }
+
+    let cookie_vec = match BASE64.decode(u_b64.as_bytes()) {
+        Ok(c) => c,
+        Err(_) => err!("Invalid Duo cookie encoding"),
+    };
+
+    let cookie = match String::from_utf8(cookie_vec) {
+        Ok(c) => c,
+        Err(_) => err!("Invalid Duo cookie encoding"),
+    };
+
+    let cookie_split: Vec<&str> = cookie.split('|').collect();
+    if cookie_split.len() != 3 {
+        err!("Invalid cookie length")
+    }
+
+    let username = cookie_split[0];
+    let u_ikey = cookie_split[1];
+    let expire = cookie_split[2];
+
+    if !crypto::ct_eq(ikey, u_ikey) {
+        err!("Invalid ikey")
+    }
+
+    let expire = match expire.parse() {
+        Ok(e) => e,
+        Err(_) => err!("Invalid expire time"),
+    };
+
+    if time >= expire {
+        err!("Expired authorization")
+    }
+
+    Ok(username.into())
+}
+
+#[derive(Deserialize)]
+#[allow(non_snake_case)]
+struct SendEmailLoginData {
+    Email: String,
+    MasterPasswordHash: String,
+}
+
+#[put("/two-factor/send-email-login", data = "<data>")] // JsonResult
+fn send_email_login(data: JsonUpcase<SendEmailLoginData>, headers: Headers, conn: DbConn) -> EmptyResult {
+    let data: SendEmailLoginData = data.into_inner().data;
+
+    use crate::db::models::User;
+
+    // Get the user
+    let mut user = match User::find_by_mail(&data.Email, &conn) {
+        Some(user) => user,
+        None => err!("Username or password is incorrect. Try again."),
+    };
+
+    // Check password
+    if !user.check_valid_password(&data.MasterPasswordHash) {
+        err!("Username or password is incorrect. Try again.")
+    }
+
+    let type_ = TwoFactorType::Email as i32;
+    let mut twofactor = TwoFactor::find_by_user_and_type(&user.uuid, type_, &conn)?;
+
+    let decoded_key = validate_decode_key(&twofactor.data)?;
+
+    let generated_token = totp_raw_now(&decoded_key, 6, 0, 30, &HashType::SHA1);
+    let token_string = generated_token.to_string();
+
+    mail::send_token(&data.Email, &token_string)?;
+
+//    activate_u2f(data, headers, conn)
+    Ok(())
+}
+
+#[post("/two-factor/get-email", data = "<data>")]
+fn get_email(data: JsonUpcase<PasswordData>, headers: Headers, conn: DbConn) -> JsonResult {
+    let data: PasswordData = data.into_inner().data;
+    let user = headers.user;
+
+    if !user.check_valid_password(&data.MasterPasswordHash) {
+        err!("Invalid password");
+    }
+
+    let type_ = TwoFactorType::Email as i32;
+    let enabled = match TwoFactor::find_by_user_and_type(&user.uuid, type_, &conn) {
+        Some(x) => x.enabled,
+        _ => false,
+    };
+
+
+    Ok(Json(json!({// TODO check! FIX!
+        "Email": user.email,
+        "Enabled": enabled,
+        "Object": "twoFactorEmail"
+    })))
+}
+
+#[derive(Deserialize)]
+#[allow(non_snake_case)]
+struct SendEmailData {
+    Email: String, // Email where 2FA codes will be sent to, can be different than user email account.
+    MasterPasswordHash: String,
+}
+
+// Send a verification email to the specified email address to check whether it exists/belongs to user.
+#[post("/two-factor/send-email", data = "<data>")]
+fn send_email(data: JsonUpcase<SendEmailData>, headers: Headers, conn: DbConn) -> EmptyResult {
+    use oath::{totp_raw_now, HashType};
+
+    let data: SendEmailData = data.into_inner().data;
+    let user = headers.user;
+
+    if !user.check_valid_password(&data.MasterPasswordHash) {
+        err!("Invalid password");
+    }
+
+    let type_ = TwoFactorType::Email as i32;
+
+    // TODO: Delete previous email thing.
+    match TwoFactor::find_by_user_and_type(&user.uuid, type_, &conn) {
+        Some(tf) => tf.delete(&conn),
+        _ => Ok(()),
+    };
+
+    let secret = crypto::get_random(vec![0u8; 20]);
+    let base32_secret = BASE32.encode(&secret);
+
+    let mut twofactor = TwoFactor::new(user.uuid, TwoFactorType::Email, base32_secret);
+    // Disable 2fa since it's not verified yet.
+    twofactor.enabled = false;
+    twofactor.save(&conn)?;
+
+    let generated_token = totp_raw_now(&secret, 6, 0, 30, &HashType::SHA1);
+    let token_string = generated_token.to_string();
+
+    mail::send_token(&data.Email, &token_string)?;
+
+    Ok(())
+}
+
+#[derive(Deserialize,Serialize)]
+#[allow(non_snake_case)]
+struct EmailData {
+    Email: String,
+    MasterPasswordHash: String,
+    Token: String,
+}
+
+// Verify email used for 2FA email codes.
+#[put("/two-factor/email", data = "<data>")]
+fn email(data: JsonUpcase<EmailData>, headers: Headers, conn: DbConn) -> JsonResult {
+
+    let data: EmailData = data.into_inner().data;
+    let user = headers.user;
+
+    if !user.check_valid_password(&data.MasterPasswordHash) {
+        err!("Invalid password");
+    }
+
+    let token_u64 = match data.Token.parse::<u64>() {
+        Ok(token) => token,
+        _ => err!("Could not parse token"),
+    };
+
+
+    let type_ = TwoFactorType::Email as i32;
+    let mut twofactor = TwoFactor::find_by_user_and_type(&user.uuid, type_, &conn)?;
+
+    validate_totp_code(token_u64, &twofactor.data)?;
+
+    twofactor.enabled = true;
+    twofactor.save(&conn)?;
+
+    Ok(Json(json!({
+        "Email": data.Email, // TODO Fix with actual email from db.
+        "Enabled": "true",
+        "Object": "twoFactorEmail"
+    })))
+}
+
+#[derive(Serialize, Deserialize)]
+struct EmailTokenData {
+    email: String,
+    totp_secret: String,
+}
\ No newline at end of file