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 A31491FF143 for ; Sat, 11 Apr 2026 10:51:34 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id AD28B4E43; Sat, 11 Apr 2026 10:52:12 +0200 (CEST) From: Thomas Lamprecht To: c.ebner@proxmox.com Subject: Re: [PATCH proxmox-backup v2 27/27] sync: pull: decrypt snapshots with matching encryption key fingerprint Date: Sat, 11 Apr 2026 10:02:15 +0200 Message-ID: <20260411085154.1961287-11-t.lamprecht@proxmox.com> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260410165454.1578501-28-c.ebner@proxmox.com> References: <20260411085154.1961287-1-t.lamprecht@proxmox.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Bm-Milter-Handled: 55990f41-d878-4baa-be0a-ee34c49e34d2 X-Bm-Transport-Timestamp: 1775897455406 X-SPAM-LEVEL: Spam detection results: 0 AWL 0.002 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 SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record URIBL_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to URIBL was blocked. See http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block for more information. [pull.rs] Message-ID-Hash: FQZQYEWRVMKG5NUMSAZHH6NHI3XCUXAL X-Message-ID-Hash: FQZQYEWRVMKG5NUMSAZHH6NHI3XCUXAL X-MailFrom: t.lamprecht@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 CC: pbs-devel@lists.proxmox.com 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: Am 10.04.26 um 18:54 schrieb Christian Ebner: > diff --git a/src/server/pull.rs b/src/server/pull.rs > @@ -647,6 +704,22 @@ async fn pull_snapshot<'a>( > > + // pre-existing local manifest for unencrypted snapshot, never overwrite with encrypted > + if local_manifest_key_fp.is_some() && crypt_config.is_none() { > + bail!("local unencrypted snapshot detected, refuse to sync without source decryption"); > + } This condition looks inverted AFAICT. After decrypt-on-pull the local manifest has key-fingerprint: null, so manifest.fingerprint() returns None, local_manifest_key_fp is None, and the is_some() check never fires. The scenario it should catch: key removed from job after a previous decrypt-on-pull, remote snapshot changed, local decrypted data gets silently overwritten with encrypted content. I think checking local_manifest_file_fp.is_some() (the change-detection-fingerprint presence) would be the right indicator for this situation, at least FWICT that field only exists in manifests produced by the decrypt path (but might warrant a closer check). > @@ -696,11 +769,38 @@ async fn pull_snapshot<'a>( > > + new_manifest.unprotected["key-fingerprint"] = Value::Null; nit: do we need to set the field explicitly to JSON null rather than removing it via e.g. `.as_object_mut().unwrap().remove("key-fingerprint")` instead? but no hard feelings here. > + new_manifest.unprotected = manifest.unprotected.clone(); nit: this copies verify state from the encrypted source manifest into the decrypted target. The decryption itself acts as a verification of sorts (AEAD would catch corruption), so this is fine, but a comment explaining the reasoning would be IMO nice. > + info!("Found matching key fingerprint {source_fingerprint}, decrypt on pull"); nit: I'd suggest to also log which key ID matched, not just the fingerprint, as that's then easier for the admin to cross-reference with the job config.