chore(tools/rust-crates-advisory): move custom checker to user dir r/5258

Profpatsch originally implemented an advisory checker from scratch in
Rust. We now ended up just using cargo-audit for the global checks
exposed via CI and the custom implementation is unused. To clean up
//tools/rust-crates-advisory a bit, we can move the unused parts to his
user directory.

Change-Id: Iacbd27c163edd07c804220fd1b3569c23aebd3e7
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7171
Tested-by: BuildkiteCI
Reviewed-by: Profpatsch <mail@profpatsch.de>

2 files changed, 187 insertions, 0 deletions

diff --git a/users/Profpatsch/check-crate-advisory/check-security-advisory.rs b/users/Profpatsch/check-crate-advisory/check-security-advisory.rs
new file mode 100644
index 0000000000..e76b090abc
--- /dev/null
+++ b/users/Profpatsch/check-crate-advisory/check-security-advisory.rs
@@ -0,0 +1,119 @@
+extern crate semver;
+extern crate toml;
+
+use std::io::Write;
+
+/// reads a security advisory of the form
+/// https://github.com/RustSec/advisory-db/blob/a24932e220dfa9be8b0b501210fef8a0bc7ef43e/EXAMPLE_ADVISORY.md
+/// and a crate version number,
+/// and returns 0 if the crate version is patched
+/// and returns 1 if the crate version is *not* patched
+///
+/// If PRINT_ADVISORY is set, the advisory is printed if it matches.
+
+fn main() {
+    let mut args = std::env::args_os();
+    let file = args.nth(1).expect("security advisory md file is $1");
+    let crate_version = args
+        .nth(0)
+        .expect("crate version is $2")
+        .into_string()
+        .expect("crate version string not utf8");
+    let crate_version = semver::Version::parse(&crate_version)
+        .expect(&format!("this is not a semver version: {}", &crate_version));
+    let filename = file.to_string_lossy();
+
+    let content = std::fs::read(&file).expect(&format!("could not read {}", filename));
+    let content = std::str::from_utf8(&content)
+        .expect(&format!("file {} was not encoded as utf-8", filename));
+    let content = content.trim_start();
+
+    let toml_start = content
+        .strip_prefix("```toml")
+        .expect(&format!("file did not start with ```toml: {}", filename));
+    let toml_end_index = toml_start.find("```").expect(&format!(
+        "the toml section did not end, no `` found: {}",
+        filename
+    ));
+    let toml = &toml_start[..toml_end_index];
+    let toml: toml::Value = toml::de::from_slice(toml.as_bytes())
+        .expect(&format!("could not parse toml: {}", filename));
+
+    let versions = toml
+        .as_table()
+        .expect(&format!("the toml is not a table: {}", filename))
+        .get("versions")
+        .expect(&format!(
+            "the toml does not contain the versions field: {}",
+            filename
+        ))
+        .as_table()
+        .expect(&format!(
+            "the toml versions field must be a table: {}",
+            filename
+        ));
+
+    let unaffected = match versions.get("unaffected") {
+        Some(u) => u
+            .as_array()
+            .expect(&format!(
+                "the toml versions.unaffected field must be a list of semvers: {}",
+                filename
+            ))
+            .iter()
+            .map(|v| {
+                semver::VersionReq::parse(
+                    v.as_str()
+                        .expect(&format!("the version field {} is not a string", v)),
+                )
+                .expect(&format!(
+                    "the version field {} is not a valid semver VersionReq",
+                    v
+                ))
+            })
+            .collect(),
+        None => vec![],
+    };
+
+    let mut patched: Vec<semver::VersionReq> = versions
+        .get("patched")
+        .expect(&format!(
+            "the toml versions.patched field must exist: {}",
+            filename
+        ))
+        .as_array()
+        .expect(&format!(
+            "the toml versions.patched field must be a list of semvers: {}",
+            filename
+        ))
+        .iter()
+        .map(|v| {
+            semver::VersionReq::parse(
+                v.as_str()
+                    .expect(&format!("the version field {} is not a string", v)),
+            )
+            .expect(&format!(
+                "the version field {} is not a valid semver VersionReq",
+                v
+            ))
+        })
+        .collect();
+
+    patched.extend_from_slice(&unaffected[..]);
+    let is_patched_or_unaffected = patched.iter().any(|req| req.matches(&crate_version));
+
+    if is_patched_or_unaffected {
+        std::process::exit(0);
+    } else {
+        if std::env::var_os("PRINT_ADVISORY").is_some() {
+            write!(
+                std::io::stderr(),
+                "Advisory {} matched!\n{}\n",
+                filename,
+                content
+            )
+            .unwrap();
+        }
+        std::process::exit(1);
+    }
+}
diff --git a/users/Profpatsch/check-crate-advisory/default.nix b/users/Profpatsch/check-crate-advisory/default.nix
new file mode 100644
index 0000000000..e948771e2a
--- /dev/null
+++ b/users/Profpatsch/check-crate-advisory/default.nix
@@ -0,0 +1,68 @@
+{ pkgs, depot, lib, ... }:
+
+let
+  bins =
+    depot.nix.getBins pkgs.s6-portable-utils [ "s6-ln" "s6-cat" "s6-echo" "s6-mkdir" "s6-test" "s6-touch" "s6-dirname" ]
+    // depot.nix.getBins pkgs.lr [ "lr" ]
+  ;
+  crate-advisories = "${depot.third_party.rustsec-advisory-db}/crates";
+
+  check-security-advisory = depot.nix.writers.rustSimple
+    {
+      name = "parse-security-advisory";
+      dependencies = [
+        depot.third_party.rust-crates.toml
+        depot.third_party.rust-crates.semver
+      ];
+    }
+    (builtins.readFile ./check-security-advisory.rs);
+
+  # $1 is the directory with advisories for crate $2 with version $3
+  check-crate-advisory = depot.nix.writeExecline "check-crate-advisory" { readNArgs = 3; } [
+    "pipeline"
+    [ bins.lr "-0" "-t" "depth == 1" "$1" ]
+    "forstdin"
+    "-0"
+    "-Eo"
+    "0"
+    "advisory"
+    "if"
+    [ depot.tools.eprintf "advisory %s\n" "$advisory" ]
+    check-security-advisory
+    "$advisory"
+    "$3"
+  ];
+
+  # Run through everything in the `crate-advisories` repository
+  # and check whether we can parse all the advisories without crashing.
+  test-parsing-all-security-advisories = depot.nix.runExecline "check-all-our-crates" { } [
+    "pipeline"
+    [ bins.lr "-0" "-t" "depth == 1" crate-advisories ]
+    "if"
+    [
+      # this will succeed as long as check-crate-advisory doesn’t `panic!()` (status 101)
+      "forstdin"
+      "-0"
+      "-E"
+      "-x"
+      "101"
+      "crate_advisories"
+      check-crate-advisory
+      "$crate_advisories"
+      "foo"
+      "0.0.0"
+    ]
+    "importas"
+    "out"
+    "out"
+    bins.s6-touch
+    "$out"
+  ];
+in
+
+depot.nix.readTree.drvTargets {
+  inherit
+    check-crate-advisory
+    test-parsing-all-security-advisories
+    ;
+}