CI: test build on actual no_std platforms (#67)

.github/workflows/rustls-rustcrypto.yml

@@ -17,23 +17,6 @@ env:
   RUSTFLAGS: "-Dwarnings"
 
 jobs:
-  build:
-    strategy:
-      matrix:
-        toolchain:
-          - 1.75.0 # MSRV
-          - stable
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: RustCrypto/actions/cargo-cache@master
-      - uses: dtolnay/rust-toolchain@master
-        with:
-          toolchain: ${{ matrix.toolchain }}
-      - run: cargo build
-      - name: Test no_std with alloc build
-        run: cargo build --no-default-features --features tls12,alloc
-
   clippy:
     runs-on: ubuntu-latest
     steps:
@@ -63,10 +46,30 @@ jobs:
           components: rustfmt
       - run: cargo fmt --all -- --check
 
+  no_std:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        rust:
+          - 1.75.0 # MSRV
+          - stable
+        target:
+          - armv7a-none-eabi
+          - thumbv7em-none-eabi
+          - wasm32-unknown-unknown
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: ${{ matrix.rust }}
+          targets: ${{ matrix.target }}
+      - run: cargo build --no-default-features --features tls12,alloc --release --target ${{ matrix.target }}
+
   test:
     strategy:
       matrix:
         toolchain:
+          - 1.75.0 # MSRV
           - stable
     runs-on: ubuntu-latest
     steps:

Cargo.toml

@@ -13,6 +13,7 @@ categories = ["cryptography", "no-std"]
 keywords = ["rustls", "tls"]
 edition = "2021"
 rust-version = "1.75"
+resolver = "1" # Hack to enable the `custom` feature of `getrandom`
 
 # Ensure all dependencies + feats are mapped to crate features for correct usage
 # default features often have std breaking no_std and potentially other unwanted
@@ -40,6 +41,9 @@ signature = { version = "2.1.0", default-features = false }
 webpki = { package = "rustls-webpki", version = "0.102.0", default-features = false }
 x25519-dalek = { version = "2", default-features = false }
 
+[dev-dependencies]
+getrandom = { version = "0.2", features = ["custom"] } # workaround to build on no_std targets
+
 [features]
 default = ["std", "tls12", "zeroize"]
 logging = ["rustls/logging"]