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 B6FE31FF1A6 for ; Fri, 5 Dec 2025 14:25:43 +0100 (CET) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 20B781D2E5; Fri, 5 Dec 2025 14:26:09 +0100 (CET) From: Samuel Rufinatscha To: pbs-devel@lists.proxmox.com Date: Fri, 5 Dec 2025 14:25:54 +0100 Message-ID: <20251205132559.197434-2-s.rufinatscha@proxmox.com> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20251205132559.197434-1-s.rufinatscha@proxmox.com> References: <20251205132559.197434-1-s.rufinatscha@proxmox.com> MIME-Version: 1.0 X-Bm-Milter-Handled: 55990f41-d878-4baa-be0a-ee34c49e34d2 X-Bm-Transport-Timestamp: 1764941116734 X-SPAM-LEVEL: Spam detection results: 0 AWL 0.128 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 POISEN_SPAM_PILL 0.1 Meta: its spam POISEN_SPAM_PILL_1 0.1 random spam to be learned in bayes POISEN_SPAM_PILL_3 0.1 random spam to be learned in bayes RCVD_IN_VALIDITY_CERTIFIED_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to Validity was blocked. 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[proxmox.com] Subject: [pbs-devel] [PATCH proxmox-backup 1/3] pbs-config: cache verified API token secrets X-BeenThere: pbs-devel@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox Backup Server development discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Proxmox Backup Server development discussion Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: pbs-devel-bounces@lists.proxmox.com Sender: "pbs-devel" Currently, every token-based API request reads the token.shadow file and runs the expensive password hash verification for the given token secret. This shows up as a hotspot in /status profiling (see bug #6049 [1]). This patch introduces an in-memory cache of successfully verified token secrets. Subsequent requests for the same token+secret combination only perform a comparison using openssl::memcmp::eq and avoid re-running the password hash. The cache is updated when a token secret is set and cleared when a token is deleted. Note, this does NOT include manual config changes, which will be covered in a subsequent patch. This patch partly fixes bug #6049 [1]. [1] https://bugzilla.proxmox.com/show_bug.cgi?id=7017 Signed-off-by: Samuel Rufinatscha --- pbs-config/src/token_shadow.rs | 58 +++++++++++++++++++++++++++++++++- 1 file changed, 57 insertions(+), 1 deletion(-) diff --git a/pbs-config/src/token_shadow.rs b/pbs-config/src/token_shadow.rs index 640fabbf..47aa2fc2 100644 --- a/pbs-config/src/token_shadow.rs +++ b/pbs-config/src/token_shadow.rs @@ -1,6 +1,8 @@ use std::collections::HashMap; +use std::sync::RwLock; use anyhow::{bail, format_err, Error}; +use once_cell::sync::OnceCell; use serde::{Deserialize, Serialize}; use serde_json::{from_value, Value}; @@ -13,6 +15,13 @@ use crate::{open_backup_lockfile, BackupLockGuard}; const LOCK_FILE: &str = pbs_buildcfg::configdir!("/token.shadow.lock"); const CONF_FILE: &str = pbs_buildcfg::configdir!("/token.shadow"); +/// Global in-memory cache for successfully verified API token secrets. +/// The cache stores plain text secrets for token Authids that have already been +/// verified against the hashed values in `token.shadow`. This allows for cheap +/// subsequent authentications for the same token+secret combination, avoiding +/// recomputing the password hash on every request. +static TOKEN_SECRET_CACHE: OnceCell> = OnceCell::new(); + #[derive(Serialize, Deserialize)] #[serde(rename_all = "kebab-case")] /// ApiToken id / secret pair @@ -54,9 +63,25 @@ pub fn verify_secret(tokenid: &Authid, secret: &str) -> Result<(), Error> { bail!("not an API token ID"); } + // Fast path + if let Some(cached) = token_secret_cache().read().unwrap().secrets.get(tokenid) { + // Compare cached secret with provided one using constant time comparison + if openssl::memcmp::eq(cached.as_bytes(), secret.as_bytes()) { + // Already verified before + return Ok(()); + } + // Fall through to slow path if secret doesn't match cached one + } + + // Slow path: read file + verify hash let data = read_file()?; match data.get(tokenid) { - Some(hashed_secret) => proxmox_sys::crypt::verify_crypt_pw(secret, hashed_secret), + Some(hashed_secret) => { + proxmox_sys::crypt::verify_crypt_pw(secret, hashed_secret)?; + // Cache the plain secret for future requests + cache_insert_secret(tokenid.clone(), secret.to_owned()); + Ok(()) + } None => bail!("invalid API token"), } } @@ -82,6 +107,8 @@ fn set_secret(tokenid: &Authid, secret: &str) -> Result<(), Error> { data.insert(tokenid.clone(), hashed_secret); write_file(data)?; + cache_insert_secret(tokenid.clone(), secret.to_owned()); + Ok(()) } @@ -97,5 +124,34 @@ pub fn delete_secret(tokenid: &Authid) -> Result<(), Error> { data.remove(tokenid); write_file(data)?; + cache_remove_secret(tokenid); + Ok(()) } + +struct ApiTokenSecretCache { + /// Keys are token Authids, values are the corresponding plain text secrets. + /// Entries are added after a successful on-disk verification in + /// `verify_secret` or when a new token secret is generated by + /// `generate_and_set_secret`. Used to avoid repeated + /// password-hash computation on subsequent authentications. + secrets: HashMap, +} + +fn token_secret_cache() -> &'static RwLock { + TOKEN_SECRET_CACHE.get_or_init(|| { + RwLock::new(ApiTokenSecretCache { + secrets: HashMap::new(), + }) + }) +} + +fn cache_insert_secret(tokenid: Authid, secret: String) { + let mut cache = token_secret_cache().write().unwrap(); + cache.secrets.insert(tokenid, secret); +} + +fn cache_remove_secret(tokenid: &Authid) { + let mut cache = token_secret_cache().write().unwrap(); + cache.secrets.remove(tokenid); +} -- 2.47.3 _______________________________________________ pbs-devel mailing list pbs-devel@lists.proxmox.com https://lists.proxmox.com/cgi-bin/mailman/listinfo/pbs-devel