Files
sprout/crates/sprout/src/config/loader.rs

69 lines
2.5 KiB
Rust

use crate::options::SproutOptions;
use crate::platform::tpm::PlatformTpm;
use crate::utils;
use anyhow::{Context, Result, bail};
use edera_sprout_config::{RootConfiguration, latest_version};
use log::info;
use std::ops::Deref;
use toml::Value;
use uefi::proto::device_path::LoadedImageDevicePath;
/// Loads the raw configuration from the sprout config file as data.
fn load_raw_config(options: &SproutOptions) -> Result<Vec<u8>> {
// Open the LoadedImageDevicePath protocol to get the path to the current image.
let current_image_device_path_protocol =
uefi::boot::open_protocol_exclusive::<LoadedImageDevicePath>(uefi::boot::image_handle())
.context("unable to get loaded image device path")?;
// Acquire the device path as a boxed device path.
let path = current_image_device_path_protocol.deref().to_boxed();
info!("configuration file: {}", options.config);
// Read the contents of the sprout config file.
let content = utils::read_file_contents(Some(&path), &options.config)
.context("unable to read sprout config file")?;
// Measure the sprout.toml into the TPM, if needed and possible.
PlatformTpm::log_event(
PlatformTpm::PCR_BOOT_LOADER_CONFIG,
&content,
"sprout: configuration file",
)
.context("unable to measure the sprout.toml file into the TPM")?;
// Return the contents of the sprout config file.
Ok(content)
}
/// Loads the [RootConfiguration] for Sprout.
pub fn load(options: &SproutOptions) -> Result<RootConfiguration> {
// Load the raw configuration from the sprout config file.
let content = load_raw_config(options)?;
// Parse the raw configuration into a toml::Value which can represent any TOML file.
let value: Value = toml::from_slice(&content).context("unable to parse sprout config file")?;
// Check the version of the configuration without parsing the full configuration.
let version = value
.get("version")
.cloned()
.unwrap_or_else(|| Value::Integer(latest_version() as i64));
// Parse the version into an u32.
let version: u32 = version
.try_into()
.context("unable to get configuration version")?;
// Check if the version is supported.
if version != latest_version() {
bail!("unsupported configuration version: {}", version);
}
// If the version is supported, parse the full configuration.
let config: RootConfiguration = value
.try_into()
.context("unable to parse sprout.toml file")?;
// Return the parsed configuration.
Ok(config)
}