From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.proxmox.com (Postfix) with ESMTPS id 9720461984 for ; Fri, 20 Nov 2020 17:39:28 +0100 (CET) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 9525F15009 for ; Fri, 20 Nov 2020 17:39:28 +0100 (CET) Received: from proxmox-new.maurer-it.com (proxmox-new.maurer-it.com [212.186.127.180]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by firstgate.proxmox.com (Proxmox) with ESMTPS id 16D8B14FFF for ; Fri, 20 Nov 2020 17:39:28 +0100 (CET) Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id D8CCD43D48 for ; Fri, 20 Nov 2020 17:39:27 +0100 (CET) From: =?UTF-8?q?Fabian=20Gr=C3=BCnbichler?= To: pbs-devel@lists.proxmox.com Date: Fri, 20 Nov 2020 17:38:35 +0100 Message-Id: <20201120163845.1225080-6-f.gruenbichler@proxmox.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20201120163845.1225080-1-f.gruenbichler@proxmox.com> References: <20201120163845.1225080-1-f.gruenbichler@proxmox.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-SPAM-LEVEL: Spam detection results: 0 AWL 0.026 Adjusted score from AWL reputation of From: address KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment RCVD_IN_DNSWL_MED -2.3 Sender listed at https://www.dnswl.org/, medium trust 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. [manifest.rs] Subject: [pbs-devel] [PATCH proxmox-backup 05/13] fix #3139: add key fingerprint to manifest 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: , X-List-Received-Date: Fri, 20 Nov 2020 16:39:28 -0000 if the manifest is signed/the contained archives/blobs are encrypted. stored in 'unprotected' area, since there is already a strong binding between key and manifest via the signature, and this avoids breaking backwards compatibility for a simple usability improvement. Signed-off-by: Fabian Grünbichler --- Notes: v2: use Fingerprint struct here as well src/backup/manifest.rs | 38 +++++++++++++++++++++++++++++++++++++- 1 file changed, 37 insertions(+), 1 deletion(-) diff --git a/src/backup/manifest.rs b/src/backup/manifest.rs index 51980a07..00dafbd6 100644 --- a/src/backup/manifest.rs +++ b/src/backup/manifest.rs @@ -5,7 +5,7 @@ use std::path::Path; use serde_json::{json, Value}; use ::serde::{Deserialize, Serialize}; -use crate::backup::{BackupDir, CryptMode, CryptConfig}; +use crate::backup::{BackupDir, CryptMode, CryptConfig, Fingerprint}; pub const MANIFEST_BLOB_NAME: &str = "index.json.blob"; pub const MANIFEST_LOCK_NAME: &str = ".index.json.lck"; @@ -223,12 +223,48 @@ impl BackupManifest { if let Some(crypt_config) = crypt_config { let sig = self.signature(crypt_config)?; manifest["signature"] = proxmox::tools::digest_to_hex(&sig).into(); + let fingerprint = &crypt_config.fingerprint(); + manifest["unprotected"]["key-fingerprint"] = serde_json::to_value(fingerprint)?; } let manifest = serde_json::to_string_pretty(&manifest).unwrap().into(); Ok(manifest) } + pub fn fingerprint(&self) -> Result, Error> { + match &self.unprotected["key-fingerprint"] { + Value::Null => Ok(None), + value => Ok(Some(serde_json::from_value(value.clone())?)) + } + } + + /// Checks if a BackupManifest and a CryptConfig share a valid fingerprint combination. + /// + /// An unsigned manifest is valid with any or no CryptConfig. + /// A signed manifest is only valid with a matching CryptConfig. + pub fn check_fingerprint(&self, crypt_config: Option<&CryptConfig>) -> Result<(), Error> { + if let Some(fingerprint) = self.fingerprint()? { + match crypt_config { + None => bail!( + "missing key - manifest was created with key {}", + fingerprint, + ), + Some(crypt_config) => { + let config_fp = crypt_config.fingerprint(); + if config_fp != fingerprint { + bail!( + "wrong key - manifest's key {} does not match provided key {}", + fingerprint, + config_fp + ); + } + } + } + }; + + Ok(()) + } + /// Try to read the manifest. This verifies the signature if there is a crypt_config. pub fn from_data(data: &[u8], crypt_config: Option<&CryptConfig>) -> Result { let json: Value = serde_json::from_slice(data)?; -- 2.20.1