From 45ec577c2f58a53f85e56c57c7a330977adafad5 Mon Sep 17 00:00:00 2001
From: Jorge Aparicio <jorge.aparicio@ferrous-systems.com>
Date: Mon, 27 Nov 2023 17:42:25 +0100
Subject: [PATCH] CI: check no-std support

---
 .github/workflows/rust.yml      | 15 +++++++++++++++
 .gitignore                      |  1 +
 no-std-support-check/Cargo.toml | 13 +++++++++++++
 no-std-support-check/src/lib.rs |  3 +++
 4 files changed, 32 insertions(+)
 create mode 100644 no-std-support-check/Cargo.toml
 create mode 100644 no-std-support-check/src/lib.rs

diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index c1ed261..0524b83 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -108,3 +108,18 @@ jobs:
           version: latest
       - name: Fuzz Base w/ RustCrypto
         run: cargo fuzz run base -- -runs=10000
+
+  no-std-check:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      # we use a target that lacks a pre-compiled libstd to check if any dependency is using libstd
+      - name: Install stable toolchain
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+          target: thumbv7em-none-eabihf
+          default: true
+      - name: Fuzz Base w/ RustCrypto
+        run: cargo check --target thumbv7em-none-eabihf
+        working-directory: no-std-support-check
diff --git a/.gitignore b/.gitignore
index 20b656e..2c39f9c 100755
--- a/.gitignore
+++ b/.gitignore
@@ -3,6 +3,7 @@ Cargo.lock
 **/*.rs.bk
 .vscode/
 evercrypt_provider/target
+no-std-support-check/target
 rust_crypto_provider/target
 traits/target/
 .DS_Store
diff --git a/no-std-support-check/Cargo.toml b/no-std-support-check/Cargo.toml
new file mode 100644
index 0000000..4b04f9f
--- /dev/null
+++ b/no-std-support-check/Cargo.toml
@@ -0,0 +1,13 @@
+[package]
+edition = "2021"
+name = "no-std-support-check"
+publish = false
+version = "0.0.0"
+
+[dependencies]
+hpke-rs-crypto = { path = "../traits" }
+
+# the no-std-support-check CI job uses the `thumbv7em-none-eabihf` target
+# `getrandom` does not support that target out of box so this feature needs to be enabled to avoid a compilation error
+# (normally this feature should NOT be enabled in a library but this crate is just used for a CI check)
+getrandom = { version = "0.2.11", features = ["custom"] }
diff --git a/no-std-support-check/src/lib.rs b/no-std-support-check/src/lib.rs
new file mode 100644
index 0000000..f3edcff
--- /dev/null
+++ b/no-std-support-check/src/lib.rs
@@ -0,0 +1,3 @@
+//! used in CI to check that crates are no-std compatible
+
+#![no_std]