config-digest: split out config digest api type into separate crate

Signed-off-by: Dietmar Maurer <dietmar@proxmox.com>

Cargo.toml

@@ -9,6 +9,7 @@ members = [
     "proxmox-borrow",
     "proxmox-client",
     "proxmox-compression",
+    "proxmox-config-digest",
     "proxmox-http",
     "proxmox-http-error",
     "proxmox-human-byte",
@@ -113,6 +114,7 @@ proxmox-io = { version = "1.0.0", path = "proxmox-io" }
 proxmox-lang = { version = "1.1", path = "proxmox-lang" }
 proxmox-login = { version = "0.1.0", path = "proxmox-login" }
 proxmox-product-config = { version = "0.1.0", path = "proxmox-product-config" }
+proxmox-config-digest = { version = "0.1.0", path = "proxmox-config-digest" }
 proxmox-rest-server = { version = "0.5.2", path = "proxmox-rest-server" }
 proxmox-router = { version = "2.1.3", path = "proxmox-router" }
 proxmox-schema = { version = "3.1.1", path = "proxmox-schema" }

proxmox-config-digest/Cargo.toml

@@ -0,0 +1,20 @@
+[package]
+name = "proxmox-config-digest"
+version = "0.1.0"
+authors.workspace = true
+edition.workspace = true
+license.workspace = true
+repository.workspace = true
+description = "Configuration file digest API type."
+
+exclude.workspace = true
+
+[dependencies]
+anyhow.workspace = true
+hex.workspace = true
+serde.workspace = true
+serde_plain.workspace = true
+proxmox-schema = { workspace = true, features = ["api-types"] }
+
+# feature "openssl", allows to compute the SHA256 digest
+openssl = { workspace = true, optional = true }

proxmox-config-digest/debian/changelog

@@ -0,0 +1,5 @@
+rust-proxmox-config-digest (0.1.0-1) bookworm; urgency=medium
+
+  * initial packaging (split out from proxmox-product-config)
+
+ -- Proxmox Support Team <support@proxmox.com>  Wed, 29 May 2024 17:49:33 +0200

proxmox-config-digest/debian/control

@@ -0,0 +1,59 @@
+Source: rust-proxmox-config-digest
+Section: rust
+Priority: optional
+Build-Depends: debhelper (>= 12),
+ dh-cargo (>= 25),
+ cargo:native <!nocheck>,
+ rustc:native <!nocheck>,
+ libstd-rust-dev <!nocheck>,
+ librust-anyhow-1+default-dev <!nocheck>,
+ librust-hex-0.4+default-dev <!nocheck>,
+ librust-proxmox-schema-3+api-types-dev (>= 3.1.1-~~) <!nocheck>,
+ librust-proxmox-schema-3+default-dev (>= 3.1.1-~~) <!nocheck>,
+ librust-serde-1+default-dev <!nocheck>,
+ librust-serde-plain-1+default-dev <!nocheck>
+Maintainer: Proxmox Support Team <support@proxmox.com>
+Standards-Version: 4.6.2
+Vcs-Git: git://git.proxmox.com/git/proxmox.git
+Vcs-Browser: https://git.proxmox.com/?p=proxmox.git
+X-Cargo-Crate: proxmox-config-digest
+Rules-Requires-Root: no
+
+Package: librust-proxmox-config-digest-dev
+Architecture: any
+Multi-Arch: same
+Depends:
+ ${misc:Depends},
+ librust-anyhow-1+default-dev,
+ librust-hex-0.4+default-dev,
+ librust-proxmox-schema-3+api-types-dev (>= 3.1.1-~~),
+ librust-proxmox-schema-3+default-dev (>= 3.1.1-~~),
+ librust-serde-1+default-dev,
+ librust-serde-plain-1+default-dev
+Suggests:
+ librust-proxmox-config-digest+openssl-dev (= ${binary:Version})
+Provides:
+ librust-proxmox-config-digest+default-dev (= ${binary:Version}),
+ librust-proxmox-config-digest-0-dev (= ${binary:Version}),
+ librust-proxmox-config-digest-0+default-dev (= ${binary:Version}),
+ librust-proxmox-config-digest-0.1-dev (= ${binary:Version}),
+ librust-proxmox-config-digest-0.1+default-dev (= ${binary:Version}),
+ librust-proxmox-config-digest-0.1.0-dev (= ${binary:Version}),
+ librust-proxmox-config-digest-0.1.0+default-dev (= ${binary:Version})
+Description: Configuration file digest API type - Rust source code
+ Source code for Debianized Rust crate "proxmox-config-digest"
+
+Package: librust-proxmox-config-digest+openssl-dev
+Architecture: any
+Multi-Arch: same
+Depends:
+ ${misc:Depends},
+ librust-proxmox-config-digest-dev (= ${binary:Version}),
+ librust-openssl-0.10+default-dev
+Provides:
+ librust-proxmox-config-digest-0+openssl-dev (= ${binary:Version}),
+ librust-proxmox-config-digest-0.1+openssl-dev (= ${binary:Version}),
+ librust-proxmox-config-digest-0.1.0+openssl-dev (= ${binary:Version})
+Description: Configuration file digest API type - feature "openssl"
+ This metapackage enables feature "openssl" for the Rust proxmox-config-digest
+ crate, by pulling in any additional dependencies needed by that feature.

proxmox-config-digest/debian/copyright

@@ -0,0 +1,18 @@
+Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
+
+Files:
+ *
+Copyright: 2019 - 2023 Proxmox Server Solutions GmbH <support@proxmox.com>
+License: AGPL-3.0-or-later
+ This program is free software: you can redistribute it and/or modify it under
+ the terms of the GNU Affero General Public License as published by the Free
+ Software Foundation, either version 3 of the License, or (at your option) any
+ later version.
+ .
+ This program is distributed in the hope that it will be useful, but WITHOUT
+ ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+ details.
+ .
+ You should have received a copy of the GNU Affero General Public License along
+ with this program. If not, see <https://www.gnu.org/licenses/>.

proxmox-config-digest/debian/debcargo.toml

@@ -0,0 +1,7 @@
+overlay = "."
+crate_src_path = ".."
+maintainer = "Proxmox Support Team <support@proxmox.com>"
+
+[source]
+vcs_git = "git://git.proxmox.com/git/proxmox.git"
+vcs_browser = "https://git.proxmox.com/?p=proxmox.git"

proxmox-config-digest/src/lib.rs

@@ -0,0 +1,112 @@
+use anyhow::{bail, Error};
+
+#[cfg(feature = "openssl")]
+use openssl::sha;
+
+use proxmox_schema::api_types::SHA256_HEX_REGEX;
+use proxmox_schema::ApiStringFormat;
+use proxmox_schema::ApiType;
+use proxmox_schema::Schema;
+use proxmox_schema::StringSchema;
+
+pub const PROXMOX_CONFIG_DIGEST_FORMAT: ApiStringFormat =
+    ApiStringFormat::Pattern(&SHA256_HEX_REGEX);
+
+pub const PROXMOX_CONFIG_DIGEST_SCHEMA: Schema = StringSchema::new(
+    "Prevent changes if current configuration file has different \
+    SHA256 digest. This can be used to prevent concurrent \
+    modifications.",
+)
+.format(&PROXMOX_CONFIG_DIGEST_FORMAT)
+.schema();
+
+#[derive(Clone, Debug, Eq, PartialEq)]
+/// A configuration digest - a SHA256 hash.
+pub struct ConfigDigest([u8; 32]);
+
+impl ConfigDigest {
+    pub fn to_hex(&self) -> String {
+        hex::encode(&self.0[..])
+    }
+
+    #[cfg(feature = "openssl")]
+    pub fn from_slice<T: AsRef<[u8]>>(data: T) -> ConfigDigest {
+        let digest = sha::sha256(data.as_ref());
+        ConfigDigest(digest)
+    }
+
+    /// Detect modified configuration files
+    ///
+    /// This function fails with a reasonable error message if checksums do not match.
+    pub fn detect_modification(&self, user_digest: Option<&Self>) -> Result<(), Error> {
+        if let Some(user_digest) = user_digest {
+            if user_digest != self {
+                bail!("detected modified configuration - file changed by other user? Try again.");
+            }
+        }
+        Ok(())
+    }
+}
+
+impl ApiType for ConfigDigest {
+    const API_SCHEMA: Schema = PROXMOX_CONFIG_DIGEST_SCHEMA;
+}
+
+impl From<[u8; 32]> for ConfigDigest {
+    #[inline]
+    fn from(digest: [u8; 32]) -> Self {
+        Self(digest)
+    }
+}
+
+impl From<ConfigDigest> for [u8; 32] {
+    #[inline]
+    fn from(digest: ConfigDigest) -> Self {
+        digest.0
+    }
+}
+
+impl AsRef<[u8]> for ConfigDigest {
+    fn as_ref(&self) -> &[u8] {
+        &self.0
+    }
+}
+
+impl AsRef<[u8; 32]> for ConfigDigest {
+    fn as_ref(&self) -> &[u8; 32] {
+        &self.0
+    }
+}
+
+impl std::ops::Deref for ConfigDigest {
+    type Target = [u8; 32];
+
+    fn deref(&self) -> &[u8; 32] {
+        &self.0
+    }
+}
+
+impl std::ops::DerefMut for ConfigDigest {
+    fn deref_mut(&mut self) -> &mut [u8; 32] {
+        &mut self.0
+    }
+}
+
+impl std::fmt::Display for ConfigDigest {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.to_hex())
+    }
+}
+
+impl std::str::FromStr for ConfigDigest {
+    type Err = hex::FromHexError;
+
+    fn from_str(s: &str) -> Result<Self, hex::FromHexError> {
+        let mut digest = [0u8; 32];
+        hex::decode_to_slice(s, &mut digest)?;
+        Ok(ConfigDigest(digest))
+    }
+}
+
+serde_plain::derive_deserialize_from_fromstr!(ConfigDigest, "valid configuration digest");
+serde_plain::derive_serialize_from_display!(ConfigDigest);