From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68]) by lore.proxmox.com (Postfix) with ESMTPS id 66B801FF141 for ; Tue, 05 May 2026 10:36:31 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 20FC41D0A6; Tue, 5 May 2026 10:34:07 +0200 (CEST) From: Arthur Bied-Charreton To: pve-devel@lists.proxmox.com, pbs-devel@lists.proxmox.com Subject: [PATCH proxmox v5 09/27] notify: smtp: add XOAUTH2 authentication support Date: Tue, 5 May 2026 10:32:30 +0200 Message-ID: <20260505083248.36450-10-a.bied-charreton@proxmox.com> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260505083248.36450-1-a.bied-charreton@proxmox.com> References: <20260505083248.36450-1-a.bied-charreton@proxmox.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SPAM-LEVEL: Spam detection results: 0 AWL -0.114 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% DMARC_MISSING 0.1 Missing DMARC policy KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment KAM_LAZY_DOMAIN_SECURITY 1 Sending domain does not have any anti-forgery methods RDNS_NONE 0.793 Delivered to internal network by a host with no rDNS SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_NONE 0.001 SPF: sender does not publish an SPF Record Message-ID-Hash: VFJX5UBWEG52TKV73YZPNWLS5K337TNZ X-Message-ID-Hash: VFJX5UBWEG52TKV73YZPNWLS5K337TNZ X-MailFrom: abied-charreton@jett.proxmox.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; loop; banned-address; emergency; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.10 Precedence: list List-Id: Proxmox Backup Server development discussion List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: Extend the transport building logic to authenticate via XOAUTH2 if configured. Previously, the authentication method was determined based on the presence of a password in the config. In order to ensure backwards compatibility with older configurations, continue to do so if auth_method is not set, ensuring configurations that used PLAIN auth before this series keep working as expected. Signed-off-by: Arthur Bied-Charreton --- proxmox-notify/src/endpoints/smtp.rs | 87 +++++++++++++++++++++++----- 1 file changed, 74 insertions(+), 13 deletions(-) diff --git a/proxmox-notify/src/endpoints/smtp.rs b/proxmox-notify/src/endpoints/smtp.rs index dcc01bb5..353fe4cd 100644 --- a/proxmox-notify/src/endpoints/smtp.rs +++ b/proxmox-notify/src/endpoints/smtp.rs @@ -3,11 +3,12 @@ use std::time::{Duration, SystemTime, UNIX_EPOCH}; use lettre::message::header::{HeaderName, HeaderValue}; use lettre::message::{Mailbox, MultiPart, SinglePart}; +use lettre::transport::smtp::authentication::{Credentials, Mechanism}; use lettre::transport::smtp::client::{Tls, TlsParameters}; use lettre::{message::header::ContentType, Message, SmtpTransport, Transport}; use oauth2::{ClientId, ClientSecret, RefreshToken}; use serde::{Deserialize, Serialize}; -use tracing::info; +use tracing::{debug, info}; use proxmox_schema::api_types::COMMENT_SCHEMA; use proxmox_schema::{api, Updater}; @@ -199,7 +200,7 @@ pub struct SmtpPrivateConfig { pub oauth2_client_secret: Option, } -/// A sendmail notification endpoint. +/// A SMTP notification endpoint. pub struct SmtpEndpoint { pub config: SmtpConfig, pub private_config: SmtpPrivateConfig, @@ -243,22 +244,82 @@ impl SmtpEndpoint { } } + /// Infer the auth method based on the presence of a password field in the private config. + /// + /// This is required for backwards compatibility for configs created before the `auth_method` + /// field was added, i.e., the presence of a password implicitly meant plain authentication + /// was to be used. + fn auth_method(&self) -> Option { + self.config.auth_method.or_else(|| { + if self.private_config.password.is_some() { + Some(SmtpAuthMethod::Plain) + } else { + None + } + }) + } + + /// Build an [`SmtpTransport`] for [`Endpoint::send`]. + /// + /// For OAuth2 auth methods this loads the refresh token from the per-endpoint state file + /// and performs a token exchange at every call. It never persists a rotated token, that + /// responsibility is on [`Self::trigger_state_refresh`], which is called under a notifications + /// config lock. fn build_transport(&self, tls: Tls, port: u16) -> Result { - let mut transport_builder = SmtpTransport::builder_dangerous(&self.config.server) + let transport_builder = SmtpTransport::builder_dangerous(&self.config.server) .tls(tls) .port(port) .timeout(Some(Duration::from_secs(SMTP_TIMEOUT.into()))); - if let Some(username) = self.config.username.as_deref() { - if let Some(password) = self.private_config.password.as_deref() { - transport_builder = transport_builder.credentials((username, password).into()); - } else { - return Err(Error::NotifyFailed( - self.name().into(), - Box::new(Error::Generic( - "username is set but no password was provided".to_owned(), - )), - )); + let transport_builder = match &self.auth_method() { + None => transport_builder, + Some(SmtpAuthMethod::Plain) => match ( + self.config.username.as_deref(), + self.private_config.password.as_deref(), + ) { + (Some(username), Some(password)) => { + transport_builder.credentials((username, password).into()) + } + (Some(_), None) => { + return Err(Error::NotifyFailed( + self.name().into(), + Box::new(Error::Generic( + "username is set but no password was provided".to_owned(), + )), + )) + } + _ => transport_builder, + }, + Some(method) => { + let state = context().load_oauth_state(self.name())?; + + let refresh_token = + state + .oauth2_refresh_token + .clone() + .ok_or(Error::NotifyFailed( + self.name().into(), + Box::new(Error::Generic("no refresh token found".into())), + ))?; + + debug!( + "requesting OAuth2 access token for endpoint '{}'", + self.config.name + ); + + let token_exchange_result = self.get_access_token(&refresh_token, method)?; + + debug!( + "OAuth2 token exchange successful for endpoint '{}'", + self.config.name + ); + + transport_builder + .credentials(Credentials::new( + self.config.from_address.to_owned(), + token_exchange_result.access_token.into_secret(), + )) + .authentication(vec![Mechanism::Xoauth2]) } }; -- 2.47.3