Use bindgen to automatically generate boring-sys

This ensures that all the Rust functions, types and constants
always match the actual BoringSSL definitions.

It also removes quite a lot of manually maintained code, as well
as the need for systest.

The value for `SslOptions::ALL`, for example, was wrong. On current
BoringSSL versions, this is a no-op, and is set to `0`.

Clearing it does nothing. So, the `clear_ctx_options` test, that
passed by accident, was adjusted to use a different option.

The `libc` crate is not required, as we only use it for types that
are already defined in the standard library. It was removed from
`boring-sys`. The same can be done to other crates later.

.github/workflows/ci.yml

@@ -124,7 +124,7 @@ jobs:
           os: ubuntu-latest
         - thing: i686-msvc
           target: i686-pc-windows-msvc
-          rust: stable-i686-msvc
+          rust: stable-x86_64-msvc
           os: windows-latest
         - thing: x86_64-msvc
           target: x86_64-pc-windows-msvc
@@ -143,10 +143,19 @@ jobs:
       if: startsWith(matrix.os, 'windows')
       run: choco install nasm
       shell: cmd
+    - name: Install LLVM and Clang
+      if: startsWith(matrix.os, 'windows')
+      uses: KyleMayes/install-llvm-action@v1
+      with:
+        version: "11.0"
+        directory: ${{ runner.temp }}/llvm
+    - name: Set LIBCLANG_PATH
+      if: startsWith(matrix.os, 'windows')
+      run: echo "LIBCLANG_PATH=$((gcm clang).source -replace "clang.exe")" >> $env:GITHUB_ENV
     - if: startsWith(matrix.os, 'windows')
       # CI's Windows doesn't have require root certs
       run: cargo test --workspace --exclude tokio-boring --exclude hyper-boring
       name: Run tests (Windows)
     - if: "!startsWith(matrix.os, 'windows')"
       run: cargo test
-      name: Run tests (not Windows)
+      name: Run tests (not Windows)

Cargo.toml

@@ -2,7 +2,6 @@
 members = [
     "boring",
     "boring-sys",
-    "systest",
     "tokio-boring",
     "hyper-boring"
 ]

boring-sys/Cargo.toml

@@ -11,6 +11,7 @@ documentation = "https://docs.rs/boring-sys"
 links = "boringssl"
 readme = "README.md"
 categories = ["cryptography", "external-ffi-bindings"]
+edition = "2018"
 include = [
     "/*.md",
     "/*.toml",
@@ -25,8 +26,6 @@ include = [
     "/src",
 ]
 
-[dependencies]
-libc = "0.2"
-
 [build-dependencies]
+bindgen = "0.57"
 cmake = "0.1"

boring-sys/build.rs

@@ -172,6 +172,9 @@ fn get_boringssl_cmake_config() -> cmake::Config {
 }
 
 fn main() {
+    use std::env;
+    use std::path::PathBuf;
+
     let mut cfg = get_boringssl_cmake_config();
 
     if cfg!(feature = "fuzzing") {
@@ -191,4 +194,61 @@ fn main() {
     if cfg!(target_os = "macos") {
         println!("cargo:rustc-cdylib-link-arg=-Wl,-undefined,dynamic_lookup");
     }
+
+    let include_path = PathBuf::from("deps/boringssl/src/include");
+    let mut builder = bindgen::Builder::default()
+        .derive_copy(true)
+        .derive_debug(true)
+        .derive_default(true)
+        .derive_eq(true)
+        .default_enum_style(bindgen::EnumVariation::NewType { is_bitfield: false })
+        .default_macro_constant_type(bindgen::MacroTypeVariation::Signed)
+        .generate_comments(true)
+        .fit_macro_constants(false)
+        .size_t_is_usize(true)
+        .layout_tests(true)
+        .prepend_enum_name(true)
+        .rustfmt_bindings(true)
+        .clang_args(&["-I", include_path.to_str().unwrap()]);
+
+    let headers = [
+        "aes.h",
+        "asn1_mac.h",
+        "asn1t.h",
+        "blake2.h",
+        "blowfish.h",
+        "cast.h",
+        "chacha.h",
+        "cmac.h",
+        "cpu.h",
+        "curve25519.h",
+        "des.h",
+        "dtls1.h",
+        "hkdf.h",
+        "hrss.h",
+        "md4.h",
+        "md5.h",
+        "obj_mac.h",
+        "objects.h",
+        "opensslv.h",
+        "ossl_typ.h",
+        "pkcs12.h",
+        "poly1305.h",
+        "rand.h",
+        "rc4.h",
+        "ripemd.h",
+        "siphash.h",
+        "srtp.h",
+        "trust_token.h",
+        "x509v3.h",
+    ];
+    for header in &headers {
+        builder = builder.header(include_path.join("openssl").join(header).to_str().unwrap());
+    }
+
+    let bindings = builder.generate().expect("Unable to generate bindings");
+    let out_path = PathBuf::from(env::var("OUT_DIR").unwrap());
+    bindings
+        .write_to_file(out_path.join("bindings.rs"))
+        .expect("Couldn't write bindings!");
 }