First draft of rust-psa-crypto, Rust wrapper for (some of) mbed-crypto.

.travis.yml

@@ -1,5 +1,6 @@
 # Executing our tests on Arm64 with Travis CI
 arch: arm64
+dist: bionic
 language: rust
 script:
   - ./tests/ci.sh

Cargo.toml

@@ -1,7 +1,8 @@
 [package]
 name = "psa-crypto"
 version = "0.1.0"
-authors = ["Paul Howard <[email protected]>",
+authors = ["Edmund Grimley Evans <[email protected]>",
+           "Paul Howard <[email protected]>",
            "Ionut Mihalcea <[email protected]>",
            "Hugues de Valon <[email protected]>"]
 edition = "2018"
@@ -13,3 +14,13 @@ license = "Apache-2.0"
 repository = "https://github.com/parallaxsecond/rust-psa-crypto"
 
 [dependencies]
+lazy_static = "1.4.0"
+
+[build-dependencies]
+bindgen = "0.50.0"
+cargo_toml = "0.7.0"
+serde = { version = "1.0", features = ["derive"] }
+toml = "0.4.2"
+
+[package.metadata.config]
+mbed-crypto-version = "mbedcrypto-2.0.0"

build-conf.toml

@@ -0,0 +1,19 @@
+# Configuration values for setting up and building the Mbed Crypto library that
+# psa-crypto currently depends on
+[mbed_config]
+    # Path (either relative or absolute) where the Mbed Crypto source code will be
+    # persisted.
+    # This value default to the OUT_DIR environment variable.
+    mbed_path = "/tmp/"
+
+    # When compiling natively
+    [mbed_config.native]
+    # The compiler to use when building the Mbed Crypto library
+    # mbed_compiler = "clang"
+    # The archiver to use when building the Mbed Crypto library
+    # mbed_archiver = "ar"
+
+    # When cross-compiling for aarch64-unknown-linux-gnu target
+    [mbed_config.aarch64_unknown_linux_gnu]
+    # mbed_compiler = "aarch64-linux-gnu-gcc"
+    # mbed_archiver = "aarch64-linux-gnu-ar"

build.rs

@@ -0,0 +1,279 @@
+// Copyright 2020 Contributors to the Parsec project.
+// SPDX-License-Identifier: Apache-2.0
+
+#![deny(
+    nonstandard_style,
+    const_err,
+    dead_code,
+    improper_ctypes,
+    non_shorthand_field_patterns,
+    no_mangle_generic_items,
+    overflowing_literals,
+    path_statements,
+    patterns_in_fns_without_body,
+    private_in_public,
+    unconditional_recursion,
+    unused,
+    unused_allocation,
+    unused_comparisons,
+    unused_parens,
+    while_true,
+    missing_debug_implementations,
+    trivial_casts,
+    trivial_numeric_casts,
+    unused_extern_crates,
+    unused_import_braces,
+    unused_qualifications,
+    unused_results,
+    missing_copy_implementations
+)]
+// This one is hard to avoid.
+#![allow(clippy::multiple_crate_versions)]
+
+use cargo_toml::{Manifest, Value};
+use serde::Deserialize;
+use std::env;
+use std::io::{Error, ErrorKind, Result};
+use std::path::{Path, PathBuf};
+
+const CONFIG_TABLE_NAME: &str = "config";
+const MBED_CRYPTO_VERSION_KEY: &str = "mbed-crypto-version";
+
+const SETUP_MBED_SCRIPT_PATH: &str = "./setup_mbed_crypto.sh";
+const BUILD_CONFIG_FILE_PATH: &str = "./build-conf.toml";
+
+const DEFAULT_NATIVE_MBED_COMPILER: &str = "clang";
+const DEFAULT_NATIVE_MBED_ARCHIVER: &str = "ar";
+const DEFAULT_ARM64_MBED_COMPILER: &str = "aarch64-linux-gnu-gcc";
+const DEFAULT_ARM64_MBED_ARCHIVER: &str = "aarch64-linux-gnu-ar";
+
+#[derive(Debug, Deserialize)]
+struct Configuration {
+    mbed_config: Option<MbedConfig>,
+}
+
+#[derive(Debug, Deserialize)]
+struct MbedConfig {
+    mbed_path: Option<String>,
+    native: Option<Toolchain>,
+    aarch64_unknown_linux_gnu: Option<Toolchain>,
+}
+
+#[derive(Debug, Deserialize)]
+struct Toolchain {
+    mbed_compiler: Option<String>,
+    mbed_archiver: Option<String>,
+}
+
+fn get_configuration_string(parsec_config: &Value, key: &str) -> Result<String> {
+    let config_value = get_value_from_table(parsec_config, key)?;
+    match config_value {
+        Value::String(string) => Ok(string.clone()),
+        _ => Err(Error::new(
+            ErrorKind::InvalidInput,
+            "Configuration key missing",
+        )),
+    }
+}
+
+fn get_value_from_table<'a>(table: &'a Value, key: &str) -> Result<&'a Value> {
+    match table {
+        Value::Table(table) => table.get(key).ok_or_else(|| {
+            println!("Config table does not contain configuration key: {}", key);
+            Error::new(ErrorKind::InvalidInput, "Configuration key missing.")
+        }),
+        _ => Err(Error::new(
+            ErrorKind::InvalidInput,
+            "Value provided is not a TOML table",
+        )),
+    }
+}
+
+// Get the Mbed Crypto version to branch on from Cargo.toml file. Use that and MbedConfig to pass
+// parameters to the setup_mbed_crypto.sh script which clones and builds Mbed Crypto and create
+// a static library.
+fn setup_mbed_crypto(mbed_config: &MbedConfig, mbed_version: &str) -> Result<()> {
+    let (mbed_compiler, mbed_archiver) =
+        if std::env::var("TARGET").unwrap() == "aarch64-unknown-linux-gnu" {
+            let toolchain;
+            toolchain = mbed_config
+                .aarch64_unknown_linux_gnu
+                .as_ref()
+                .ok_or_else(|| {
+                    Error::new(
+                        ErrorKind::InvalidInput,
+                        "The aarch64_unknown_linux_gnu subtable of mbed_config should exist",
+                    )
+                })?;
+            (
+                toolchain
+                    .mbed_compiler
+                    .clone()
+                    .unwrap_or_else(|| DEFAULT_ARM64_MBED_COMPILER.to_string()),
+                toolchain
+                    .mbed_archiver
+                    .clone()
+                    .unwrap_or_else(|| DEFAULT_ARM64_MBED_ARCHIVER.to_string()),
+            )
+        } else {
+            let toolchain;
+            toolchain = mbed_config.native.as_ref().ok_or_else(|| {
+                Error::new(
+                    ErrorKind::InvalidInput,
+                    "The native subtable of mbed_config should exist",
+                )
+            })?;
+            (
+                toolchain
+                    .mbed_compiler
+                    .clone()
+                    .unwrap_or_else(|| DEFAULT_NATIVE_MBED_COMPILER.to_string()),
+                toolchain
+                    .mbed_archiver
+                    .clone()
+                    .unwrap_or_else(|| DEFAULT_NATIVE_MBED_ARCHIVER.to_string()),
+            )
+        };
+
+    let script_fail = |_| {
+        Err(Error::new(
+            ErrorKind::Other,
+            "setup_mbed_crypto.sh script failed",
+        ))
+    };
+
+    println!("cargo:rerun-if-changed={}", SETUP_MBED_SCRIPT_PATH);
+    println!("cargo:rerun-if-changed={}", "src/c/Makefile");
+    println!("cargo:rerun-if-changed={}", "src/c/shim.c");
+    println!("cargo:rerun-if-changed={}", "src/c/shim.h");
+
+    if !::std::process::Command::new(SETUP_MBED_SCRIPT_PATH)
+        .arg(mbed_version)
+        .arg(
+            mbed_config
+                .mbed_path
+                .clone()
+                .unwrap_or_else(|| env::var("OUT_DIR").unwrap()),
+        )
+        .arg(format!("CC={}", mbed_compiler))
+        .arg(format!("AR={}", mbed_archiver))
+        .status()
+        .or_else(script_fail)?
+        .success()
+    {
+        Err(Error::new(
+            ErrorKind::Other,
+            "setup_mbed_crypto.sh returned an error status.",
+        ))
+    } else {
+        Ok(())
+    }
+}
+
+fn generate_mbed_bindings(mbed_config: &MbedConfig, mbed_version: &str) -> Result<()> {
+    let mbed_include_dir = mbed_config
+        .mbed_path
+        .clone()
+        .unwrap_or_else(|| env::var("OUT_DIR").unwrap())
+        + "/mbed-crypto-"
+        + mbed_version
+        + "/include";
+    let header = mbed_include_dir.clone() + "/psa/crypto.h";
+
+    println!("cargo:rerun-if-changed={}", header);
+
+    let shim_bindings = bindgen::Builder::default()
+        .clang_arg(format!("-I{}", mbed_include_dir))
+        .rustfmt_bindings(true)
+        .header("src/c/shim.h")
+        .generate_comments(false)
+        .generate()
+        .or_else(|_| {
+            Err(Error::new(
+                ErrorKind::Other,
+                "Unable to generate bindings to mbed crypto",
+            ))
+        })?;
+    let out_path = PathBuf::from(env::var("OUT_DIR").unwrap());
+    shim_bindings.write_to_file(out_path.join("shim_bindings.rs"))
+}
+
+// Get the compiler, the archiver and the location where to clone the Mbed Crypto repository.
+fn parse_config_file() -> Result<Configuration> {
+    let config_str = ::std::fs::read_to_string(Path::new(BUILD_CONFIG_FILE_PATH))?;
+    Ok(toml::from_str(&config_str).or_else(|e| {
+        println!("Error parsing build configuration file ({}).", e);
+        Err(Error::new(
+            ErrorKind::InvalidInput,
+            "Could not parse build configuration file.",
+        ))
+    })?)
+}
+
+fn main() -> Result<()> {
+    // Parsing build-conf.toml
+    let config = parse_config_file()?;
+
+    // Parsing Cargo.toml
+    let toml_path = std::path::Path::new("./Cargo.toml");
+    if !toml_path.exists() {
+        return Err(Error::new(
+            ErrorKind::InvalidInput,
+            "Could not find Cargo.toml.",
+        ));
+    }
+    let manifest = Manifest::from_path(&toml_path).or_else(|e| {
+        println!("Error parsing Cargo.toml ({}).", e);
+        Err(Error::new(
+            ErrorKind::InvalidInput,
+            "Could not parse Cargo.toml.",
+        ))
+    })?;
+
+    let package = manifest.package.ok_or_else(|| {
+        Error::new(
+            ErrorKind::InvalidInput,
+            "Cargo.toml does not contain package information.",
+        )
+    })?;
+    let metadata = package.metadata.ok_or_else(|| {
+        Error::new(
+            ErrorKind::InvalidInput,
+            "Cargo.toml does not contain package metadata.",
+        )
+    })?;
+    let parsec_config = get_value_from_table(&metadata, CONFIG_TABLE_NAME)?;
+
+    if true {
+        let mbed_config = config.mbed_config.ok_or_else(|| {
+            Error::new(
+                ErrorKind::InvalidInput,
+                "Could not find mbed_config table in the config file.",
+            )
+        })?;
+
+        let mbed_version = get_configuration_string(&parsec_config, MBED_CRYPTO_VERSION_KEY)?;
+
+        setup_mbed_crypto(&mbed_config, &mbed_version)?;
+        generate_mbed_bindings(&mbed_config, &mbed_version)?;
+
+        // Request rustc to link the Mbed Crypto static library
+        println!(
+            "cargo:rustc-link-search=native={}/mbed-crypto-{}/library/",
+            mbed_config
+                .mbed_path
+                .unwrap_or_else(|| env::var("OUT_DIR").unwrap()),
+            mbed_version,
+        );
+        println!("cargo:rustc-link-lib=static=mbedcrypto");
+
+        // Also link shim library
+        println!(
+            "cargo:rustc-link-search=native={}",
+            env::var("OUT_DIR").unwrap()
+        );
+        println!("cargo:rustc-link-lib=static=shim");
+    }
+
+    Ok(())
+}