use once_cell::sync::Lazy; use std::process::exit; use std::sync::RwLock; use reqwest::Url; use crate::error::Error; use crate::util::{get_env, get_env_bool}; static CONFIG_FILE: Lazy = Lazy::new(|| { let data_folder = get_env("DATA_FOLDER").unwrap_or_else(|| String::from("data")); get_env("CONFIG_FILE").unwrap_or_else(|| format!("{}/config.json", data_folder)) }); pub static CONFIG: Lazy = Lazy::new(|| { Config::load().unwrap_or_else(|e| { println!("Error loading config:\n\t{:?}\n", e); exit(12) }) }); pub type Pass = String; macro_rules! make_config { ($( $(#[doc = $groupdoc:literal])? $group:ident $(: $group_enabled:ident)? { $( $(#[doc = $doc:literal])+ $name:ident : $ty:ident, $editable:literal, $none_action:ident $(, $default:expr)?; )+}, )+) => { pub struct Config { inner: RwLock } struct Inner { templates: Handlebars<'static>, config: ConfigItems, _env: ConfigBuilder, _usr: ConfigBuilder, } #[derive(Debug, Clone, Default, Deserialize, Serialize)] pub struct ConfigBuilder { $($( #[serde(skip_serializing_if = "Option::is_none")] $name: Option<$ty>, )+)+ } impl ConfigBuilder { fn from_env() -> Self { dotenv::from_path(".env").ok(); let mut builder = ConfigBuilder::default(); $($( builder.$name = make_config! { @getenv &stringify!($name).to_uppercase(), $ty }; )+)+ builder } fn from_file(path: &str) -> Result { use crate::util::read_file_string; let config_str = read_file_string(path)?; serde_json::from_str(&config_str).map_err(Into::into) } /// Merges the values of both builders into a new builder. /// If both have the same element, `other` wins. fn merge(&self, other: &Self, show_overrides: bool) -> Self { let mut overrides = Vec::new(); let mut builder = self.clone(); $($( if let v @Some(_) = &other.$name { builder.$name = v.clone(); if self.$name.is_some() { overrides.push(stringify!($name).to_uppercase()); } } )+)+ if show_overrides && !overrides.is_empty() { // We can't use warn! here because logging isn't setup yet. println!("[WARNING] The following environment variables are being overriden by the config file,"); println!("[WARNING] please use the admin panel to make changes to them:"); println!("[WARNING] {}\n", overrides.join(", ")); } builder } /// Returns a new builder with all the elements from self, /// except those that are equal in both sides fn _remove(&self, other: &Self) -> Self { let mut builder = ConfigBuilder::default(); $($( if &self.$name != &other.$name { builder.$name = self.$name.clone(); } )+)+ builder } fn build(&self) -> ConfigItems { let mut config = ConfigItems::default(); let _domain_set = self.domain.is_some(); $($( config.$name = make_config!{ @build self.$name.clone(), &config, $none_action, $($default)? }; )+)+ config.domain_set = _domain_set; config.signups_domains_whitelist = config.signups_domains_whitelist.trim().to_lowercase(); config } } #[derive(Debug, Clone, Default)] pub struct ConfigItems { $($(pub $name: make_config!{@type $ty, $none_action}, )+)+ } #[allow(unused)] impl Config { $($( pub fn $name(&self) -> make_config!{@type $ty, $none_action} { self.inner.read().unwrap().config.$name.clone() } )+)+ pub fn prepare_json(&self) -> serde_json::Value { let (def, cfg) = { let inner = &self.inner.read().unwrap(); (inner._env.build(), inner.config.clone()) }; fn _get_form_type(rust_type: &str) -> &'static str { match rust_type { "Pass" => "password", "String" => "text", "bool" => "checkbox", _ => "number" } } fn _get_doc(doc: &str) -> serde_json::Value { let mut split = doc.split("|>").map(str::trim); json!({ "name": split.next(), "description": split.next() }) } json!([ $({ "group": stringify!($group), "grouptoggle": stringify!($($group_enabled)?), "groupdoc": make_config!{ @show $($groupdoc)? }, "elements": [ $( { "editable": $editable, "name": stringify!($name), "value": cfg.$name, "default": def.$name, "type": _get_form_type(stringify!($ty)), "doc": _get_doc(concat!($($doc),+)), }, )+ ]}, )+ ]) } } }; // Group or empty string ( @show ) => { "" }; ( @show $lit:literal ) => { $lit }; // Wrap the optionals in an Option type ( @type $ty:ty, option) => { Option<$ty> }; ( @type $ty:ty, $id:ident) => { $ty }; // Generate the values depending on none_action ( @build $value:expr, $config:expr, option, ) => { $value }; ( @build $value:expr, $config:expr, def, $default:expr ) => { $value.unwrap_or($default) }; ( @build $value:expr, $config:expr, auto, $default_fn:expr ) => {{ match $value { Some(v) => v, None => { let f: &dyn Fn(&ConfigItems) -> _ = &$default_fn; f($config) } } }}; ( @build $value:expr, $config:expr, gen, $default_fn:expr ) => {{ let f: &dyn Fn(&ConfigItems) -> _ = &$default_fn; f($config) }}; ( @getenv $name:expr, bool ) => { get_env_bool($name) }; ( @getenv $name:expr, $ty:ident ) => { get_env($name) }; } //STRUCTURE: // /// Short description (without this they won't appear on the list) // group { // /// Friendly Name |> Description (Optional) // name: type, is_editable, action, // } // // Where action applied when the value wasn't provided and can be: // def: Use a default value // auto: Value is auto generated based on other values // option: Value is optional // gen: Value is always autogenerated and it's original value ignored make_config! { folders { /// Data folder |> Main data folder data_folder: String, false, def, "data".to_string(); /// Database URL database_url: String, false, auto, |c| format!("{}/{}", c.data_folder, "db.sqlite3"); /// Icon cache folder icon_cache_folder: String, false, auto, |c| format!("{}/{}", c.data_folder, "icon_cache"); /// Attachments folder attachments_folder: String, false, auto, |c| format!("{}/{}", c.data_folder, "attachments"); /// Templates folder templates_folder: String, false, auto, |c| format!("{}/{}", c.data_folder, "templates"); /// Session JWT key rsa_key_filename: String, false, auto, |c| format!("{}/{}", c.data_folder, "rsa_key"); /// Web vault folder web_vault_folder: String, false, def, "web-vault/".to_string(); }, ws { /// Enable websocket notifications websocket_enabled: bool, false, def, false; /// Websocket address websocket_address: String, false, def, "0.0.0.0".to_string(); /// Websocket port websocket_port: u16, false, def, 3012; }, /// General settings settings { /// Domain URL |> This needs to be set to the URL used to access the server, including 'http[s]://' /// and port, if it's different than the default. Some server functions don't work correctly without this value domain: String, true, def, "http://localhost".to_string(); /// Domain Set |> Indicates if the domain is set by the admin. Otherwise the default will be used. domain_set: bool, false, def, false; /// Domain origin |> Domain URL origin (in https://example.com:8443/path, https://example.com:8443 is the origin) domain_origin: String, false, auto, |c| extract_url_origin(&c.domain); /// Domain path |> Domain URL path (in https://example.com:8443/path, /path is the path) domain_path: String, false, auto, |c| extract_url_path(&c.domain); /// Enable web vault web_vault_enabled: bool, false, def, true; /// HIBP Api Key |> HaveIBeenPwned API Key, request it here: https://haveibeenpwned.com/API/Key hibp_api_key: Pass, true, option; /// Per-user attachment limit (KB) |> Limit in kilobytes for a users attachments, once the limit is exceeded it won't be possible to upload more user_attachment_limit: i64, true, option; /// Per-organization attachment limit (KB) |> Limit in kilobytes for an organization attachments, once the limit is exceeded it won't be possible to upload more org_attachment_limit: i64, true, option; /// Disable icon downloads |> Set to true to disable icon downloading, this would still serve icons from /// $ICON_CACHE_FOLDER, but it won't produce any external network request. Needs to set $ICON_CACHE_TTL to 0, /// otherwise it will delete them and they won't be downloaded again. disable_icon_download: bool, true, def, false; /// Allow new signups |> Controls whether new users can register. Users can be invited by the bitwarden_rs 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 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; /// If signups require email verification, limit how many emails are automatically sent when login is attempted (0 means no limit) signups_verify_resend_limit: u32, true, def, 6; /// Email domain whitelist |> Allow signups only from this list of comma-separated domains, even when signups are otherwise disabled signups_domains_whitelist: String, true, def, "".to_string(); /// Allow invitations |> Controls whether users can be invited by organization admins, even when signups are otherwise disabled invitations_allowed: bool, true, def, true; /// Password iterations |> Number of server-side passwords hashing iterations. /// The changes only apply when a user changes their password. Not recommended to lower the value password_iterations: i32, true, def, 100_000; /// Show password hints |> Controls if the password hint should be shown directly in the web page. /// Otherwise, if email is disabled, there is no way to see the password hint show_password_hint: bool, true, def, true; /// Admin page token |> The token used to authenticate in this very same page. Changing it here won't deauthorize the current session admin_token: Pass, true, option; /// Invitation organization name |> Name shown in the invitation emails that don't come from a specific organization invitation_org_name: String, true, def, "Bitwarden_RS".to_string(); }, /// Advanced settings advanced { /// Client IP header |> If not present, the remote IP is used. /// Set to the string "none" (without quotes), to disable any headers and just use the remote IP ip_header: String, true, def, "X-Real-IP".to_string(); /// Internal IP header property, used to avoid recomputing each time _ip_header_enabled: bool, false, gen, |c| &c.ip_header.trim().to_lowercase() != "none"; /// Positive icon cache expiry |> Number of seconds to consider that an already cached icon is fresh. After this period, the icon will be redownloaded icon_cache_ttl: u64, true, def, 2_592_000; /// Negative icon cache expiry |> Number of seconds before trying to download an icon that failed again. icon_cache_negttl: u64, true, def, 259_200; /// Icon download timeout |> Number of seconds when to stop attempting to download an icon. icon_download_timeout: u64, true, def, 10; /// Icon blacklist Regex |> Any domains or IPs that match this regex won't be fetched by the icon service. /// Useful to hide other servers in the local network. Check the WIKI for more details icon_blacklist_regex: String, true, option; /// Icon blacklist non global IPs |> Any IP which is not defined as a global IP will be blacklisted. /// Usefull to secure your internal environment: See https://en.wikipedia.org/wiki/Reserved_IP_addresses for a list of IPs which it will block icon_blacklist_non_global_ips: bool, true, def, true; /// Disable Two-Factor remember |> Enabling this would force the users to use a second factor to login every time. /// Note that the checkbox would still be present, but ignored. disable_2fa_remember: bool, true, def, false; /// Disable authenticator time drifted codes to be valid |> Enabling this only allows the current TOTP code to be valid /// TOTP codes of the previous and next 30 seconds will be invalid. authenticator_disable_time_drift: bool, true, def, false; /// Require new device emails |> When a user logs in an email is required to be sent. /// If sending the email fails the login attempt will fail. require_device_email: bool, true, def, false; /// Reload templates (Dev) |> When this is set to true, the templates get reloaded with every request. /// ONLY use this during development, as it can slow down the server reload_templates: bool, true, def, false; /// Enable extended logging extended_logging: bool, false, def, true; /// Enable the log to output to Syslog use_syslog: bool, false, def, false; /// Log file path log_file: String, false, option; /// Log level log_level: String, false, def, "Info".to_string(); /// Enable DB WAL |> Turning this off might lead to worse performance, but might help if using bitwarden_rs on some exotic filesystems, /// that do not support WAL. Please make sure you read project wiki on the topic before changing this setting. enable_db_wal: bool, false, def, true; /// Bypass admin page security (Know the risks!) |> Disables the Admin Token for the admin page so you may use your own auth in-front disable_admin_token: bool, true, def, false; /// Allowed iframe ancestors (Know the risks!) |> Allows other domains to embed the web vault into an iframe, useful for embedding into secure intranets allowed_iframe_ancestors: String, true, def, String::new(); }, /// Yubikey settings yubico: _enable_yubico { /// Enabled _enable_yubico: bool, true, def, true; /// Client ID yubico_client_id: String, true, option; /// Secret Key yubico_secret_key: Pass, true, option; /// Server yubico_server: String, true, option; }, /// Global Duo settings (Note that users can override them) duo: _enable_duo { /// Enabled _enable_duo: bool, true, def, false; /// Integration Key duo_ikey: String, true, option; /// Secret Key duo_skey: Pass, true, option; /// Host duo_host: String, true, option; /// Application Key (generated automatically) _duo_akey: Pass, false, option; }, /// SMTP Email Settings smtp: _enable_smtp { /// Enabled _enable_smtp: bool, true, def, true; /// Host smtp_host: String, true, option; /// Enable SSL smtp_ssl: bool, true, def, true; /// Use explicit TLS |> Enabling this would force the use of an explicit TLS connection, instead of upgrading an insecure one with STARTTLS smtp_explicit_tls: bool, true, def, false; /// Port smtp_port: u16, true, auto, |c| if c.smtp_explicit_tls {465} else if c.smtp_ssl {587} else {25}; /// From Address smtp_from: String, true, def, String::new(); /// From Name smtp_from_name: String, true, def, "Bitwarden_RS".to_string(); /// Username smtp_username: String, true, option; /// Password smtp_password: Pass, true, option; /// Json form auth mechanism |> Defaults for ssl is "Plain" and "Login" and nothing for non-ssl connections. Possible values: ["Plain", "Login", "Xoauth2"] smtp_auth_mechanism: String, true, option; /// SMTP connection timeout |> Number of seconds when to stop trying to connect to the SMTP server smtp_timeout: u64, true, def, 15; }, /// Email 2FA Settings email_2fa: _enable_email_2fa { /// Enabled |> Disabling will prevent users from setting up new email 2FA and using existing email 2FA configured _enable_email_2fa: bool, true, auto, |c| c._enable_smtp && c.smtp_host.is_some(); /// Token number length |> Length of the numbers in an email token. Minimum of 6. Maximum is 19. email_token_size: u32, true, def, 6; /// Token expiration time |> Maximum time in seconds a token is valid. The time the user has to open email client and copy token. email_expiration_time: u64, true, def, 600; /// Maximum attempts |> Maximum attempts before an email token is reset and a new email will need to be sent email_attempts_limit: u64, true, def, 3; }, } fn validate_config(cfg: &ConfigItems) -> Result<(), Error> { let db_url = cfg.database_url.to_lowercase(); if cfg!(feature = "sqlite") && (db_url.starts_with("mysql:") || db_url.starts_with("postgresql:")) { err!("`DATABASE_URL` is meant for MySQL or Postgres, while this server is meant for SQLite") } if cfg!(feature = "mysql") && !db_url.starts_with("mysql:") { err!("`DATABASE_URL` should start with mysql: when using the MySQL server") } if cfg!(feature = "postgresql") && !db_url.starts_with("postgresql:") { err!("`DATABASE_URL` should start with postgresql: when using the PostgreSQL server") } let dom = cfg.domain.to_lowercase(); if !dom.starts_with("http://") && !dom.starts_with("https://") { err!("DOMAIN variable needs to contain the protocol (http, https). Use 'http[s]://bw.example.com' instead of 'bw.example.com'"); } let whitelist = &cfg.signups_domains_whitelist; if !whitelist.is_empty() && whitelist.split(',').any(|d| d.trim().is_empty()) { err!("`SIGNUPS_DOMAINS_WHITELIST` contains empty tokens"); } if let Some(ref token) = cfg.admin_token { if token.trim().is_empty() && !cfg.disable_admin_token { println!("[WARNING] `ADMIN_TOKEN` is enabled but has an empty value, so the admin page will be disabled."); println!("[WARNING] To enable the admin page without a token, use `DISABLE_ADMIN_TOKEN`."); } } if cfg._enable_duo && (cfg.duo_host.is_some() || cfg.duo_ikey.is_some() || cfg.duo_skey.is_some()) && !(cfg.duo_host.is_some() && cfg.duo_ikey.is_some() && cfg.duo_skey.is_some()) { err!("All Duo options need to be set for global Duo support") } if cfg._enable_yubico && cfg.yubico_client_id.is_some() != cfg.yubico_secret_key.is_some() { err!("Both `YUBICO_CLIENT_ID` and `YUBICO_SECRET_KEY` need to be set for Yubikey OTP support") } if cfg._enable_smtp { if cfg.smtp_host.is_some() == cfg.smtp_from.is_empty() { err!("Both `SMTP_HOST` and `SMTP_FROM` need to be set for email support") } if cfg.smtp_username.is_some() != cfg.smtp_password.is_some() { err!("Both `SMTP_USERNAME` and `SMTP_PASSWORD` need to be set to enable email authentication") } if cfg._enable_email_2fa && (!cfg._enable_smtp || cfg.smtp_host.is_none()) { err!("To enable email 2FA, SMTP must be configured") } if cfg._enable_email_2fa && cfg.email_token_size < 6 { err!("`EMAIL_TOKEN_SIZE` has a minimum size of 6") } if cfg._enable_email_2fa && cfg.email_token_size > 19 { err!("`EMAIL_TOKEN_SIZE` has a maximum size of 19") } } Ok(()) } /// Extracts an RFC 6454 web origin from a URL. fn extract_url_origin(url: &str) -> String { match Url::parse(url) { Ok(u) => u.origin().ascii_serialization(), Err(e) => { println!("Error validating domain: {}", e); String::new() } } } /// Extracts the path from a URL. /// All trailing '/' chars are trimmed, even if the path is a lone '/'. fn extract_url_path(url: &str) -> String { match Url::parse(url) { Ok(u) => u.path().trim_end_matches('/').to_string(), Err(_) => { // We already print it in the method above, no need to do it again String::new() } } } impl Config { pub fn load() -> Result { // Loading from env and file let _env = ConfigBuilder::from_env(); let _usr = ConfigBuilder::from_file(&CONFIG_FILE).unwrap_or_default(); // Create merged config, config file overwrites env let builder = _env.merge(&_usr, true); // Fill any missing with defaults let config = builder.build(); validate_config(&config)?; Ok(Config { inner: RwLock::new(Inner { templates: load_templates(&config.templates_folder), config, _env, _usr }), }) } pub fn update_config(&self, other: ConfigBuilder) -> Result<(), Error> { // Remove default values //let builder = other.remove(&self.inner.read().unwrap()._env); // TODO: Remove values that are defaults, above only checks those set by env and not the defaults let builder = other; // Serialize now before we consume the builder let config_str = serde_json::to_string_pretty(&builder)?; // Prepare the combined config let config = { let env = &self.inner.read().unwrap()._env; env.merge(&builder, false).build() }; validate_config(&config)?; // Save both the user and the combined config { let mut writer = self.inner.write().unwrap(); writer.config = config; writer._usr = builder; } //Save to file use std::{fs::File, io::Write}; let mut file = File::create(&*CONFIG_FILE)?; file.write_all(config_str.as_bytes())?; Ok(()) } pub fn update_config_partial(&self, other: ConfigBuilder) -> Result<(), Error> { let builder = { let usr = &self.inner.read().unwrap()._usr; usr.merge(&other, false) }; self.update_config(builder) } /// Tests whether an email's domain is allowed. A domain is allowed if it /// is in signups_domains_whitelist, or if no whitelist is set (so there /// are no domain restrictions in effect). pub fn is_email_domain_allowed(&self, email: &str) -> bool { let e: Vec<&str> = email.rsplitn(2, '@').collect(); if e.len() != 2 || e[0].is_empty() || e[1].is_empty() { warn!("Failed to parse email address '{}'", email); return false; } let email_domain = e[0].to_lowercase(); let whitelist = self.signups_domains_whitelist(); whitelist.is_empty() || whitelist.split(',').any(|d| d.trim() == email_domain) } /// Tests whether signup is allowed for an email address, taking into /// account the signups_allowed and signups_domains_whitelist settings. pub fn is_signup_allowed(&self, email: &str) -> bool { if !self.signups_domains_whitelist().is_empty() { // The whitelist setting overrides the signups_allowed setting. self.is_email_domain_allowed(email) } else { self.signups_allowed() } } pub fn delete_user_config(&self) -> Result<(), Error> { crate::util::delete_file(&CONFIG_FILE)?; // Empty user config let usr = ConfigBuilder::default(); // Config now is env + defaults let config = { let env = &self.inner.read().unwrap()._env; env.build() }; // Save configs { let mut writer = self.inner.write().unwrap(); writer.config = config; writer._usr = usr; } Ok(()) } pub fn private_rsa_key(&self) -> String { format!("{}.der", CONFIG.rsa_key_filename()) } pub fn private_rsa_key_pem(&self) -> String { format!("{}.pem", CONFIG.rsa_key_filename()) } pub fn public_rsa_key(&self) -> String { format!("{}.pub.der", CONFIG.rsa_key_filename()) } pub fn mail_enabled(&self) -> bool { let inner = &self.inner.read().unwrap().config; inner._enable_smtp && inner.smtp_host.is_some() } pub fn get_duo_akey(&self) -> String { if let Some(akey) = self._duo_akey() { akey } else { let akey = crate::crypto::get_random_64(); let akey_s = data_encoding::BASE64.encode(&akey); // Save the new value let mut builder = ConfigBuilder::default(); builder._duo_akey = Some(akey_s.clone()); self.update_config_partial(builder).ok(); akey_s } } /// Tests whether the admin token is set to a non-empty value. pub fn is_admin_token_set(&self) -> bool { let token = self.admin_token(); token.is_some() && !token.unwrap().trim().is_empty() } pub fn render_template( &self, name: &str, data: &T, ) -> Result { if CONFIG.reload_templates() { warn!("RELOADING TEMPLATES"); let hb = load_templates(CONFIG.templates_folder()); hb.render(name, data).map_err(Into::into) } else { let hb = &CONFIG.inner.read().unwrap().templates; hb.render(name, data).map_err(Into::into) } } } use handlebars::{Context, Handlebars, Helper, HelperResult, Output, RenderContext, RenderError, Renderable}; fn load_templates

(path: P) -> Handlebars<'static> where P: AsRef, { let mut hb = Handlebars::new(); // Error on missing params hb.set_strict_mode(true); // Register helpers hb.register_helper("case", Box::new(case_helper)); hb.register_helper("jsesc", Box::new(js_escape_helper)); macro_rules! reg { ($name:expr) => {{ let template = include_str!(concat!("static/templates/", $name, ".hbs")); hb.register_template_string($name, template).unwrap(); }}; ($name:expr, $ext:expr) => {{ reg!($name); reg!(concat!($name, $ext)); }}; } // First register default templates here reg!("email/change_email", ".html"); reg!("email/delete_account", ".html"); reg!("email/invite_accepted", ".html"); reg!("email/invite_confirmed", ".html"); reg!("email/new_device_logged_in", ".html"); reg!("email/pw_hint_none", ".html"); reg!("email/pw_hint_some", ".html"); reg!("email/send_org_invite", ".html"); reg!("email/twofactor_email", ".html"); reg!("email/verify_email", ".html"); reg!("email/welcome", ".html"); reg!("email/welcome_must_verify", ".html"); reg!("email/smtp_test", ".html"); reg!("admin/base"); reg!("admin/login"); reg!("admin/settings"); reg!("admin/users"); reg!("admin/organizations"); reg!("admin/diagnostics"); // And then load user templates to overwrite the defaults // Use .hbs extension for the files // Templates get registered with their relative name hb.register_templates_directory(".hbs", path).unwrap(); hb } fn case_helper<'reg, 'rc>( h: &Helper<'reg, 'rc>, r: &'reg Handlebars, ctx: &'rc Context, rc: &mut RenderContext<'reg, 'rc>, out: &mut dyn Output, ) -> HelperResult { let param = h .param(0) .ok_or_else(|| RenderError::new("Param not found for helper \"case\""))?; let value = param.value().clone(); if h.params().iter().skip(1).any(|x| x.value() == &value) { h.template().map(|t| t.render(r, ctx, rc, out)).unwrap_or(Ok(())) } else { Ok(()) } } fn js_escape_helper<'reg, 'rc>( h: &Helper<'reg, 'rc>, _r: &'reg Handlebars, _ctx: &'rc Context, _rc: &mut RenderContext<'reg, 'rc>, out: &mut dyn Output, ) -> HelperResult { let param = h .param(0) .ok_or_else(|| RenderError::new("Param not found for helper \"js_escape\""))?; let value = param .value() .as_str() .ok_or_else(|| RenderError::new("Param for helper \"js_escape\" is not a String"))?; let escaped_value = value.replace('\\', "").replace('\'', "\\x22").replace('\"', "\\x27"); let quoted_value = format!(""{}"", escaped_value); out.write("ed_value)?; Ok(()) }