use anyhow::{Context, Result, anyhow};
use sha2::{Digest, Sha256};
use std::os::unix::fs::PermissionsExt;
use std::path::{Path, PathBuf};
use std::process::{Command, ExitCode};
use std::time::{SystemTime, UNIX_EPOCH};
const RELEASES: &str = "https://github.com/dot-ASH/umbriel-mcp/releases";
const RELEASES_OVERRIDE: &str = "UMBRIEL_MCP_RELEASES";
const ASSET_PREFIX: &str = "umbriel-mcp-";
const ASSET_SUFFIX: &str = "-linux.tar.gz";
const BINARY: &str = "umbriel-mcp";
const DOWNLOAD_TIMEOUT_SECONDS: &str = "120";
const CHECK_TIMEOUT_SECONDS: &str = "10";
const RELEASE_KEY: &str = include_str!("../release-signing-key.pem");
#[cfg(debug_assertions)]
const RELEASE_KEY_OVERRIDE_FOR_TESTS: &str = "UMBRIEL_MCP_RELEASE_KEY";
#[derive(Debug, PartialEq, Eq)]
pub struct Release {
pub tag: String,
pub version: (u64, u64, u64),
}
#[derive(Debug, PartialEq, Eq)]
pub enum Installation {
SelfManaged,
ManagedElsewhere(&'static str),
}
pub fn parse_version(text: &str) -> Option<(u64, u64, u64)> {
let mut parts = text.trim().trim_start_matches('v').split('.');
let mut next = || parts.next()?.parse::<u64>().ok();
let version = (next()?, next()?, next()?);
parts.next().is_none().then_some(version)
}
pub fn asset_name(tag: &str, arch: &str) -> String {
format!("{ASSET_PREFIX}{tag}-{arch}{ASSET_SUFFIX}")
}
pub fn latest_release(sums: &str, arch: &str) -> Option<Release> {
let arch_suffix = format!("-{arch}{ASSET_SUFFIX}");
sums.lines()
.filter_map(|line| line.split_whitespace().nth(1))
.filter_map(|file| {
file.strip_prefix(ASSET_PREFIX)?
.strip_suffix(arch_suffix.as_str())
})
.filter_map(|tag| {
parse_version(tag).map(|version| Release {
tag: tag.to_owned(),
version,
})
})
.max_by_key(|release| release.version)
}
pub fn digest_for(sums: &str, file: &str) -> Option<String> {
sums.lines().find_map(|line| {
let mut fields = line.split_whitespace();
let digest = fields.next()?;
(fields.next()? == file && digest.len() == 64).then(|| digest.to_lowercase())
})
}
pub fn classify(executable: &Path) -> Installation {
let path = executable.to_string_lossy();
if path.starts_with("/usr/bin/") || path.starts_with("/bin/") || path.starts_with("/usr/sbin/")
{
return Installation::ManagedElsewhere(
"it was installed by your system package manager, so update it there (for the AUR \
package: `yay -Syu umbriel-mcp-bin`; for a makepkg build: rebuild the recipe)",
);
}
if path.contains("/.cargo/bin/") {
return Installation::ManagedElsewhere(
"it was installed with cargo, so update it with `cargo install umbriel-mcp --locked`",
);
}
if path.starts_with("/nix/") {
return Installation::ManagedElsewhere("it was installed with Nix, so update it there");
}
Installation::SelfManaged
}
pub fn verify_release_signature(public_key_pem: &str, sums: &[u8], signature: &[u8]) -> Result<()> {
let key = ed25519_compact::PublicKey::from_pem(public_key_pem)
.map_err(|error| anyhow!("the release signing key is unreadable: {error}"))?;
let signature = ed25519_compact::Signature::from_slice(signature)
.map_err(|_| anyhow!("the release signature does not match the release signing key"))?;
key.verify(sums, &signature).map_err(|_| {
anyhow!(
"the release signature does not match the release signing key, so the release may \
have been tampered with; nothing was changed"
)
})
}
fn trusted_release_key() -> Result<String> {
#[cfg(debug_assertions)]
if let Ok(path) = std::env::var(RELEASE_KEY_OVERRIDE_FOR_TESTS) {
return std::fs::read_to_string(&path).with_context(|| format!("cannot read {path}"));
}
Ok(RELEASE_KEY.to_owned())
}
fn releases_base() -> String {
std::env::var(RELEASES_OVERRIDE)
.ok()
.filter(|base| !base.is_empty())
.unwrap_or_else(|| RELEASES.to_owned())
.trim_end_matches('/')
.to_owned()
}
fn curl(url: &str, timeout_seconds: &str, destination: Option<&Path>) -> Result<Vec<u8>> {
let mut command = Command::new("curl");
command.args(["-fsSL", "--max-time", timeout_seconds]);
if let Some(destination) = destination {
command.arg("-o").arg(destination);
}
let output = command.arg(url).output().map_err(|cause| {
anyhow!("updating needs curl ({cause}); install it with your package manager")
})?;
if !output.status.success() {
return Err(anyhow!(
"could not download {url}: {}",
String::from_utf8_lossy(&output.stderr).trim()
));
}
Ok(output.stdout)
}
fn latest(timeout_seconds: &str) -> Result<(Release, String)> {
let url = format!("{}/latest/download/SHA256SUMS", releases_base());
let sums = String::from_utf8_lossy(&curl(&url, timeout_seconds, None)?).into_owned();
newest_in(sums)
}
fn latest_signed() -> Result<(Release, String)> {
let base = releases_base();
let sums = curl(
&format!("{base}/latest/download/SHA256SUMS"),
DOWNLOAD_TIMEOUT_SECONDS,
None,
)?;
let signature = curl(
&format!("{base}/latest/download/SHA256SUMS.sig"),
DOWNLOAD_TIMEOUT_SECONDS,
None,
)
.map_err(|_| {
anyhow!(
"the latest release is not signed (it has no SHA256SUMS.sig), so it was not \
installed; nothing was changed"
)
})?;
verify_release_signature(&trusted_release_key()?, &sums, &signature)?;
newest_in(String::from_utf8_lossy(&sums).into_owned())
}
fn newest_in(sums: String) -> Result<(Release, String)> {
let release = latest_release(&sums, std::env::consts::ARCH).ok_or_else(|| {
anyhow!(
"the latest release has no build for {} Linux",
std::env::consts::ARCH
)
})?;
Ok((release, sums))
}
fn current_version() -> (u64, u64, u64) {
parse_version(env!("CARGO_PKG_VERSION")).expect("the crate version is x.y.z")
}
fn dotted((major, minor, patch): (u64, u64, u64)) -> String {
format!("{major}.{minor}.{patch}")
}
pub fn notice() -> String {
match latest(CHECK_TIMEOUT_SECONDS) {
Ok((release, _)) if release.version > current_version() => format!(
"Update available: {} (you have {}). Run `umbriel-mcp update`.",
dotted(release.version),
env!("CARGO_PKG_VERSION")
),
Ok(_) => format!(
"umbriel-mcp {} is the latest version.",
env!("CARGO_PKG_VERSION")
),
Err(error) => format!("Could not check for updates: {error:#}"),
}
}
struct WorkDirectory(PathBuf);
impl WorkDirectory {
fn create() -> Result<Self> {
let nanos = SystemTime::now()
.duration_since(UNIX_EPOCH)
.map(|elapsed| elapsed.as_nanos())
.unwrap_or_default();
let path =
std::env::temp_dir().join(format!("umbriel-mcp-update-{}-{nanos}", std::process::id()));
std::fs::create_dir(&path).with_context(|| format!("cannot create {}", path.display()))?;
std::fs::set_permissions(&path, std::fs::Permissions::from_mode(0o700))?;
Ok(Self(path))
}
}
impl Drop for WorkDirectory {
fn drop(&mut self) {
let _ = std::fs::remove_dir_all(&self.0);
}
}
fn sha256_hex(file: &Path) -> Result<String> {
let bytes = std::fs::read(file).with_context(|| format!("cannot read {}", file.display()))?;
Ok(Sha256::digest(&bytes)
.iter()
.map(|byte| format!("{byte:02x}"))
.collect())
}
fn staging_path(executable: &Path) -> PathBuf {
executable.with_file_name(format!(".{BINARY}.update-{}", std::process::id()))
}
fn refuse_unwritable(executable: &Path) -> Result<()> {
let probe = staging_path(executable);
match std::fs::File::create(&probe) {
Ok(_) => {
let _ = std::fs::remove_file(&probe);
Ok(())
}
Err(error) if error.kind() == std::io::ErrorKind::PermissionDenied => Err(anyhow!(
"cannot replace {} because its folder is not writable by you; run \
`sudo umbriel-mcp update`, or reinstall into ~/.local/bin with the install script",
executable.display()
)),
Err(error) => Err(anyhow!(
"cannot write next to {}: {error}",
executable.display()
)),
}
}
fn download_verified(release: &Release, sums: &str, work: &Path) -> Result<PathBuf> {
let asset = asset_name(&release.tag, std::env::consts::ARCH);
let expected = digest_for(sums, &asset)
.ok_or_else(|| anyhow!("SHA256SUMS has no checksum for {asset}"))?;
let tarball = work.join(&asset);
let url = format!("{}/download/{}/{asset}", releases_base(), release.tag);
curl(&url, DOWNLOAD_TIMEOUT_SECONDS, Some(&tarball))?;
let actual = sha256_hex(&tarball)?;
if actual != expected {
return Err(anyhow!(
"the download of {asset} does not match its published checksum (expected {expected}, \
got {actual}); nothing was changed"
));
}
let extracted = Command::new("tar")
.arg("-xzf")
.arg(&tarball)
.arg("-C")
.arg(work)
.output()
.map_err(|cause| anyhow!("updating needs tar ({cause})"))?;
if !extracted.status.success() {
return Err(anyhow!(
"could not unpack {asset}: {}",
String::from_utf8_lossy(&extracted.stderr).trim()
));
}
let binary = work.join(asset.trim_end_matches(".tar.gz")).join(BINARY);
if !binary.is_file() {
return Err(anyhow!("{asset} does not contain {BINARY}"));
}
Ok(binary)
}
fn confirm_it_runs(binary: &Path, release: &Release) -> Result<()> {
std::fs::set_permissions(binary, std::fs::Permissions::from_mode(0o755))?;
let output = Command::new(binary)
.arg("--version")
.output()
.map_err(|cause| {
anyhow!("the downloaded {BINARY} does not run ({cause}); nothing was changed")
})?;
let reported = String::from_utf8_lossy(&output.stdout);
let expected = format!("{BINARY} {}", dotted(release.version));
if !output.status.success() || reported.trim() != expected {
return Err(anyhow!(
"the downloaded {BINARY} reports {:?} instead of {expected:?}; nothing was changed",
reported.trim()
));
}
Ok(())
}
fn replace(executable: &Path, binary: &Path) -> Result<()> {
let staged = staging_path(executable);
let result = (|| -> Result<()> {
std::fs::copy(binary, &staged)
.with_context(|| format!("cannot write {}", staged.display()))?;
let permissions = std::fs::metadata(executable)
.map(|metadata| metadata.permissions())
.unwrap_or_else(|_| std::fs::Permissions::from_mode(0o755));
std::fs::set_permissions(&staged, permissions)?;
std::fs::rename(&staged, executable)
.with_context(|| format!("cannot replace {}", executable.display()))
})();
if result.is_err() {
let _ = std::fs::remove_file(&staged);
}
result
}
fn update(check_only: bool) -> Result<String> {
let executable = std::env::current_exe()
.and_then(std::fs::canonicalize)
.context("cannot find the running umbriel-mcp executable")?;
let (release, sums) = if check_only {
latest(DOWNLOAD_TIMEOUT_SECONDS)?
} else {
latest_signed()?
};
let current = env!("CARGO_PKG_VERSION");
if release.version <= current_version() {
return Ok(format!("umbriel-mcp {current} is up to date."));
}
let newer = dotted(release.version);
let installation = classify(&executable);
if check_only {
let how = match installation {
Installation::SelfManaged => "run `umbriel-mcp update`".to_owned(),
Installation::ManagedElsewhere(advice) => advice.to_owned(),
};
return Ok(format!(
"Update available: {newer} (you have {current}); {how}."
));
}
if let Installation::ManagedElsewhere(advice) = installation {
return Err(anyhow!(
"umbriel-mcp {newer} is available, but {} was not updated: {advice}.",
executable.display()
));
}
refuse_unwritable(&executable)?;
let work = WorkDirectory::create()?;
let binary = download_verified(&release, &sums, &work.0)?;
confirm_it_runs(&binary, &release)?;
replace(&executable, &binary)?;
Ok(format!(
"Updated {} from {current} to {newer}. Restart your harness, or start a new session, so \
it uses the new version.",
executable.display()
))
}
pub fn run(check_only: bool) -> ExitCode {
match update(check_only) {
Ok(report) => {
println!("{report}");
ExitCode::SUCCESS
}
Err(error) => {
eprintln!("{error:#}");
ExitCode::FAILURE
}
}
}
#[cfg(test)]
mod tests {
use super::{
Installation, Release, asset_name, classify, digest_for, latest_release, parse_version,
};
use std::path::Path;
const SUMS: &str = "\
1111111111111111111111111111111111111111111111111111111111111111 umbriel-mcp-v0.3.0-aarch64-linux.tar.gz
2222222222222222222222222222222222222222222222222222222222222222 umbriel-mcp-v0.3.0-x86_64-linux.tar.gz
";
#[test]
fn versions_parse_with_or_without_a_leading_v() {
assert_eq!(parse_version("0.2.10"), Some((0, 2, 10)));
assert_eq!(parse_version("v1.0.0"), Some((1, 0, 0)));
assert_eq!(parse_version("1.0"), None);
assert_eq!(parse_version("x.y.z"), None);
assert!(
parse_version("0.2.10") > parse_version("0.2.9"),
"numeric, not text, ordering"
);
}
#[test]
fn the_latest_release_is_read_from_its_checksum_list() {
assert_eq!(
latest_release(SUMS, "x86_64"),
Some(Release {
tag: "v0.3.0".into(),
version: (0, 3, 0)
})
);
assert_eq!(latest_release(SUMS, "riscv64"), None);
assert_eq!(latest_release("garbage\n", "x86_64"), None);
}
#[test]
fn asset_names_and_digests_match_the_release_layout() {
assert_eq!(
asset_name("v0.3.0", "x86_64"),
"umbriel-mcp-v0.3.0-x86_64-linux.tar.gz"
);
assert_eq!(
digest_for(SUMS, "umbriel-mcp-v0.3.0-x86_64-linux.tar.gz").as_deref(),
Some("2222222222222222222222222222222222222222222222222222222222222222")
);
assert_eq!(
digest_for(SUMS, "umbriel-mcp-v0.3.0-x86_64-linux.tar"),
None
);
}
#[test]
fn binaries_owned_by_a_package_manager_are_not_self_updated() {
assert_eq!(
classify(Path::new("/home/u/.local/bin/umbriel-mcp")),
Installation::SelfManaged
);
assert_eq!(
classify(Path::new("/usr/local/bin/umbriel-mcp")),
Installation::SelfManaged
);
assert_eq!(
classify(Path::new("/opt/tools/umbriel-mcp")),
Installation::SelfManaged
);
for managed in [
"/usr/bin/umbriel-mcp",
"/bin/umbriel-mcp",
"/home/u/.cargo/bin/umbriel-mcp",
"/nix/store/abc-umbriel-mcp/bin/umbriel-mcp",
] {
assert!(
matches!(
classify(Path::new(managed)),
Installation::ManagedElsewhere(_)
),
"{managed}"
);
}
let Installation::ManagedElsewhere(advice) =
classify(Path::new("/home/u/.cargo/bin/umbriel-mcp"))
else {
unreachable!()
};
assert!(advice.contains("cargo install umbriel-mcp"), "{advice}");
}
#[test]
fn the_embedded_release_key_is_a_readable_ed25519_key() {
assert!(ed25519_compact::PublicKey::from_pem(super::RELEASE_KEY).is_ok());
}
#[test]
fn signatures_are_checked_against_the_given_key() {
let key_pair = ed25519_compact::KeyPair::from_seed(ed25519_compact::Seed::new([7; 32]));
let public = key_pair.pk.to_pem();
let sums = b"abc umbriel-mcp-v1.0.0-x86_64-linux.tar.gz\n";
let signature = key_pair.sk.sign(sums, None);
assert!(super::verify_release_signature(&public, sums, signature.as_ref()).is_ok());
assert!(super::verify_release_signature(&public, b"changed", signature.as_ref()).is_err());
assert!(super::verify_release_signature(&public, sums, &[0; 10]).is_err());
let other = ed25519_compact::KeyPair::from_seed(ed25519_compact::Seed::new([8; 32]));
assert!(
super::verify_release_signature(&other.pk.to_pem(), sums, signature.as_ref()).is_err()
);
}
}