feat: pin downloaded binaries with sha256 verification

Every binary the runner downloads at install time (the patched valgrind
.deb, the memtrack/exec-harness/mongo-tracer installer scripts) is now
SHA-256-pinned. URLs and expected hashes live together in a new
`PinnedBinary` enum, and the download helper rejects the install if the
bytes don't match.

Bumping a pinned version requires updating both the version constant and
the matching hash; CONTRIBUTING.md documents the regeneration workflow.

Co-Authored-By: Claude <noreply@anthropic.com>

Author: art049

CONTRIBUTING.md

@@ -35,19 +35,24 @@ cargo release -p exec-harness --execute beta
 
 After releasing `memtrack` or `exec-harness`, you **must** update the version references in the runner code:
 
-1. **For memtrack**: Update `MEMTRACK_CODSPEED_VERSION` in `src/executor/memory/executor.rs`:
+1. **For memtrack**: Update `MEMTRACK_VERSION` in `src/binary_pins.rs` and the matching SHA-256 in `PinnedBinary::sha256` (see [Pinned binary hashes](#pinned-binary-hashes) below).
 
-   ```rust
-   const MEMTRACK_CODSPEED_VERSION: &str = "X.Y.Z"; // Update to new version
-   ```
-
-2. **For exec-harness**: Update `EXEC_HARNESS_VERSION` in `src/executor/orchestrator.rs`:
-   ```rust
-   const EXEC_HARNESS_VERSION: &str = "X.Y.Z"; // Update to new version
-   ```
+2. **For exec-harness**: Update `EXEC_HARNESS_VERSION` in `src/binary_pins.rs` and the matching SHA-256 in `PinnedBinary::sha256`.
 
 These constants are used by the runner to download and install the correct versions of the binaries from GitHub releases.
 
+### Pinned binary hashes
+
+Every binary the runner downloads at install time (the patched valgrind `.deb`, the memtrack installer, the exec-harness installer, the mongo-tracer installer) is SHA-256-pinned. URLs and hashes live together in `PinnedBinary` in `src/binary_pins.rs`.
+
+When you bump a pinned version, regenerate the hash for each affected URL and update the matching match arm in `PinnedBinary::sha256`:
+
+```bash
+curl -sL '<url>' | sha256sum
+```
+
+For valgrind, that is one hash per supported `(distro_version, arch)` combination.
+
 ### Releasing the Main Runner
 
 The main runner (`codspeed-runner`) should be released after ensuring all dependency versions are correct.
@@ -56,8 +61,10 @@ The main runner (`codspeed-runner`) should be released after ensuring all depend
 
 **Verify binary version references**: Check that version constants in the runner code match the released versions:
 
-- `MEMTRACK_CODSPEED_VERSION` in `src/executor/memory/executor.rs`
-- `EXEC_HARNESS_VERSION` in `src/executor/orchestrator.rs`
+- `MEMTRACK_VERSION` in `src/binary_pins.rs`
+- `EXEC_HARNESS_VERSION` in `src/binary_pins.rs`
+
+Also confirm the SHA-256 entries in `PinnedBinary::sha256` (in `src/binary_pins.rs`) match the released artifacts.
 
 #### Release Command
 

src/binary_installer/mod.rs

@@ -1,29 +1,26 @@
-use crate::cli::run::helpers::download_file;
+use crate::binary_pins::PinnedBinary;
+use crate::cli::run::helpers::download_pinned_file;
 use crate::prelude::*;
 use semver::Version;
 use std::process::Command;
 use tempfile::NamedTempFile;
-use url::Url;
 
 mod versions;
 
-/// Ensure a binary is installed, or install it from a runner's GitHub release using the installer script.
+/// Ensure a binary is installed, or install it from a `PinnedBinary` installer script.
 ///
 /// This function checks if the binary is already installed with the correct version.
-/// If not, it downloads and executes an installer script from the CodSpeed runner repository.
+/// If not, it downloads and executes the pinned installer script.
 ///
 /// # Arguments
 /// * `binary_name` - The binary command name (e.g., "codspeed-memtrack", "codspeed-exec-harness")
 /// * `version` - The version to install (e.g., "4.4.2-alpha.2")
-/// * `get_installer_url` - A closure that returns the URL to download the installer script.
-pub async fn ensure_binary_installed<F>(
+/// * `installer` - The `PinnedBinary` installer to download.
+pub async fn ensure_binary_installed(
     binary_name: &str,
     version: &str,
-    get_installer_url: F,
-) -> Result<()>
-where
-    F: FnOnce() -> String,
-{
+    installer: PinnedBinary,
+) -> Result<()> {
     if is_command_installed(
         binary_name,
         Version::parse(version).context("Invalid version format")?,
@@ -32,13 +29,11 @@ where
         return Ok(());
     }
 
-    let installer_url = Url::parse(&get_installer_url()).context("Invalid installer URL")?;
+    debug!("Downloading installer for {binary_name}");
 
-    debug!("Downloading installer from: {installer_url}");
-
-    // Download the installer script to a temporary file
+    // Download the installer script to a temporary file (with sha256 verification)
     let temp_file = NamedTempFile::new().context("Failed to create temporary file")?;
-    download_file(&installer_url, temp_file.path()).await?;
+    download_pinned_file(installer, temp_file.path()).await?;
 
     // Execute the installer script
     let output = Command::new("sh")

src/binary_pins.rs

@@ -0,0 +1,76 @@
+// Pinned downloads. Each `PinnedBinary` variant carries the URL and the
+// expected SHA-256 of the file at that URL — bumping a version requires
+// updating both. See CONTRIBUTING.md for the regeneration workflow.
+
+pub const VALGRIND_DEB_VERSION: &str = "3.26.0-0codspeed0";
+pub const MEMTRACK_VERSION: &str = "1.2.3";
+pub const EXEC_HARNESS_VERSION: &str = "1.3.0";
+pub const MONGODB_TRACER_VERSION: &str = "cs-mongo-tracer-v0.2.0";
+
+/// A binary the runner downloads at install time. The download helper looks
+/// up the URL and SHA-256 via `url()` and `sha256()` and rejects the install
+/// if the bytes don't match.
+#[derive(Debug, Clone, Copy)]
+pub enum PinnedBinary {
+    ValgrindDeb {
+        distro_version: &'static str,
+        arch: &'static str,
+    },
+    MemtrackInstaller,
+    ExecHarnessInstaller,
+    MongoTracerInstaller,
+}
+
+impl PinnedBinary {
+    pub fn url(&self) -> String {
+        match self {
+            PinnedBinary::ValgrindDeb {
+                distro_version,
+                arch,
+            } => format!(
+                "https://github.com/CodSpeedHQ/valgrind-codspeed/releases/download/{VALGRIND_DEB_VERSION}/valgrind_{VALGRIND_DEB_VERSION}_ubuntu-{distro_version}_{arch}.deb"
+            ),
+            PinnedBinary::MemtrackInstaller => format!(
+                "https://github.com/CodSpeedHQ/codspeed/releases/download/memtrack-v{MEMTRACK_VERSION}/memtrack-installer.sh"
+            ),
+            PinnedBinary::ExecHarnessInstaller => format!(
+                "https://github.com/CodSpeedHQ/codspeed/releases/download/exec-harness-v{EXEC_HARNESS_VERSION}/exec-harness-installer.sh"
+            ),
+            PinnedBinary::MongoTracerInstaller => format!(
+                "https://codspeed-public-assets.s3.eu-west-1.amazonaws.com/mongo-tracer/{MONGODB_TRACER_VERSION}/cs-mongo-tracer-installer.sh"
+            ),
+        }
+    }
+
+    pub fn sha256(&self) -> &'static str {
+        match self {
+            PinnedBinary::ValgrindDeb {
+                distro_version,
+                arch,
+            } => match (*distro_version, *arch) {
+                ("22.04", "amd64") => {
+                    "e0743f01668d664a97d85903057da7557dbf2dbbf0ceeb88e6b67ae9fb2f392f"
+                }
+                ("24.04", "amd64") => {
+                    "2f02fd8e9377168310258ea03b356f4fa4beda3557e50da85681a3df889a886a"
+                }
+                ("22.04", "arm64") => {
+                    "f24fc0676b8e0fd16de8efb8ab2a1dec0083304469883c03e553fb881dd5df29"
+                }
+                ("24.04", "arm64") => {
+                    "32a48910da4b094192ef5c83e6526712fbf03b3d76a12e84423cbf6cc9ecbadf"
+                }
+                (d, a) => unreachable!("unknown valgrind target {d}/{a}"),
+            },
+            PinnedBinary::MemtrackInstaller => {
+                "67f30ebe17d5da4246b51d8663394026385d95203ff09e81289772159e969603"
+            }
+            PinnedBinary::ExecHarnessInstaller => {
+                "75cbff4fdaefe98927d24fff43fd600c621eb1263b0c40b0fd32c68fa6d88ebd"
+            }
+            PinnedBinary::MongoTracerInstaller => {
+                "685f1d540cb24c2aa6f447991958339c6b70ec7664df2dba2713b8b3d77687e7"
+            }
+        }
+    }
+}

src/cli/run/helpers/download_file.rs

@@ -1,9 +1,10 @@
+use crate::binary_pins::PinnedBinary;
 use crate::{prelude::*, request_client::REQUEST_CLIENT};
 use std::path::Path;
 
 use url::Url;
 
-pub async fn download_file(url: &Url, path: &Path) -> Result<()> {
+async fn download_file(url: &Url, path: &Path) -> Result<()> {
     debug!("Downloading file: {url}");
     let response = REQUEST_CLIENT
         .get(url.clone())
@@ -23,3 +24,26 @@ pub async fn download_file(url: &Url, path: &Path) -> Result<()> {
         .map_err(|e| anyhow!("Failed to write to file: {}, {}", path.display(), e))?;
     Ok(())
 }
+
+/// Download a `PinnedBinary` and verify its bytes against the SHA-256
+/// declared by `PinnedBinary::sha256`. On mismatch the partial file is
+/// removed and an error is returned.
+pub async fn download_pinned_file(binary: PinnedBinary, path: &Path) -> Result<()> {
+    let url_str = binary.url();
+    let url = Url::parse(&url_str).context("failed to parse pinned URL")?;
+    download_file(&url, path).await?;
+
+    let actual = sha256::try_digest(path)
+        .with_context(|| format!("failed to compute sha256 of {}", path.display()))?;
+    let expected = binary.sha256();
+
+    if actual != expected {
+        let _ = std::fs::remove_file(path);
+        bail!(
+            "Hash mismatch for {url_str}: expected {expected}, got {actual}. The downloaded file has been deleted."
+        );
+    }
+
+    debug!("Verified sha256 of {url_str}");
+    Ok(())
+}

src/cli/run/helpers/mod.rs

@@ -5,7 +5,7 @@ mod format_memory;
 mod get_env_var;
 mod parse_git_remote;
 
-pub(crate) use download_file::download_file;
+pub(crate) use download_file::download_pinned_file;
 pub(crate) use find_repository_root::find_repository_root;
 pub(crate) use format_duration::format_duration;
 pub(crate) use format_memory::format_memory;

src/executor/memory/setup.rs

@@ -1,10 +1,11 @@
 use crate::binary_installer::ensure_binary_installed;
+use crate::binary_pins::{self, PinnedBinary};
 use crate::executor::{ToolInstallStatus, ToolStatus};
 use crate::prelude::*;
 use std::process::Command;
 
 pub const MEMTRACK_COMMAND: &str = "codspeed-memtrack";
-pub const MEMTRACK_CODSPEED_VERSION: &str = "1.2.3";
+pub const MEMTRACK_CODSPEED_VERSION: &str = binary_pins::MEMTRACK_VERSION;
 
 pub fn get_memtrack_status() -> ToolStatus {
     let tool_name = MEMTRACK_COMMAND.to_string();
@@ -70,16 +71,10 @@ pub fn get_memtrack_status() -> ToolStatus {
 }
 
 pub async fn install_memtrack() -> Result<()> {
-    let get_memtrack_installer_url = || {
-        format!(
-            "https://github.com/CodSpeedHQ/codspeed/releases/download/memtrack-v{MEMTRACK_CODSPEED_VERSION}/memtrack-installer.sh"
-        )
-    };
-
     ensure_binary_installed(
         MEMTRACK_COMMAND,
         MEMTRACK_CODSPEED_VERSION,
-        get_memtrack_installer_url,
+        PinnedBinary::MemtrackInstaller,
     )
     .await
 }

src/executor/orchestrator.rs

@@ -1,6 +1,7 @@
 use super::{ExecutionContext, ExecutorName, get_executor_from_mode, run_executor};
 use crate::api_client::CodSpeedAPIClient;
 use crate::binary_installer::ensure_binary_installed;
+use crate::binary_pins::{self, PinnedBinary};
 use crate::cli::exec::multi_targets;
 use crate::cli::run::logger::Logger;
 use crate::executor::config::BenchmarkTarget;
@@ -18,7 +19,7 @@ use std::collections::BTreeMap;
 use std::path::{Path, PathBuf};
 
 pub const EXEC_HARNESS_COMMAND: &str = "exec-harness";
-pub const EXEC_HARNESS_VERSION: &str = "1.3.0";
+pub const EXEC_HARNESS_VERSION: &str = binary_pins::EXEC_HARNESS_VERSION;
 
 /// Shared orchestration state created once per CLI invocation.
 ///
@@ -82,11 +83,11 @@ impl Orchestrator {
             .collect();
 
         if !exec_targets.is_empty() {
-            ensure_binary_installed(EXEC_HARNESS_COMMAND, EXEC_HARNESS_VERSION, || {
-                format!(
-                    "https://github.com/CodSpeedHQ/codspeed/releases/download/exec-harness-v{EXEC_HARNESS_VERSION}/exec-harness-installer.sh"
-                )
-            })
+            ensure_binary_installed(
+                EXEC_HARNESS_COMMAND,
+                EXEC_HARNESS_VERSION,
+                PinnedBinary::ExecHarnessInstaller,
+            )
             .await?;
 
             let pipe_cmd = multi_targets::build_exec_targets_pipe_command(&exec_targets)?;