Move PE parsing into its own module

rust/lanzaboote/Cargo.lock

@@ -26,11 +26,23 @@ version = "2.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1f2d21333b679bbbac680b3eb45c86937e42f69277028f4e97b599b80b86c253"
 
+[[package]]
+name = "goblin"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "572564d6cba7d09775202c8e7eebc4d534d5ae36578ab402fb21e182a0ac9505"
+dependencies = [
+ "log",
+ "plain",
+ "scroll",
+]
+
 [[package]]
 name = "lanzaboote"
 version = "0.1.0"
 dependencies = [
  "ed25519-compact",
+ "goblin",
  "log",
  "uefi",
  "uefi-services",
@@ -45,6 +57,12 @@ dependencies = [
  "cfg-if",
 ]
 
+[[package]]
+name = "plain"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b4596b6d070b27117e987119b4dac604f3c58cfb0b191112e24771b2faeac1a6"
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.47"
@@ -63,6 +81,26 @@ dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "scroll"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "04c565b551bafbef4157586fa379538366e4385d42082f255bfd96e4fe8519da"
+dependencies = [
+ "scroll_derive",
+]
+
+[[package]]
+name = "scroll_derive"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bdbda6ac5cd1321e724fa9cee216f3a61885889b896f073b8f82322789c5250e"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "syn"
 version = "1.0.103"

rust/lanzaboote/Cargo.toml

@@ -5,10 +5,11 @@ edition = "2021"
 publish = false
 
 [dependencies]
-uefi = { version = "0.18.0", features = [ "alloc", "logger", "exts" ] }
-uefi-services = "0.15.0"
+uefi = { version = "0.18.0", default-features = false, features = [ "alloc", "exts" ] }
+uefi-services = { version = "0.15.0", default-features = false, features = [ "panic_handler" ] }
 log = "0.4.17"
 ed25519-compact = { version = "2.0.2", default-features = false, features = [] }
+goblin = { version = "0.6.0", default-features = false, features = [ "pe64", "alloc" ]}
 
 [profile.release]
 opt-level = "s"

rust/lanzaboote/src/main.rs

@@ -4,26 +4,24 @@
 
 extern crate alloc;
 
+mod pe_section;
+
 use alloc::vec::Vec;
-use log::debug;
+use log::{debug, info};
 use uefi::{
     prelude::*,
     proto::{
         console::text::Output,
-        device_path::{
-            text::{AllowShortcuts, DevicePathToText, DisplayOnly},
-            DevicePath,
-        },
-        loaded_image::{self, LoadedImage},
-        media::{
-            file::{File, FileAttribute, FileMode, RegularFile},
-            fs::SimpleFileSystem,
-        },
+        device_path::text::{AllowShortcuts, DevicePathToText, DisplayOnly},
+        loaded_image::LoadedImage,
+        media::file::{File, FileAttribute, FileMode, RegularFile},
     },
     table::boot::{OpenProtocolAttributes, OpenProtocolParams},
-    Error, Result,
+    Result,
 };
 
+use crate::pe_section::pe_section;
+
 fn print_logo(output: &mut Output) {
     output.clear().unwrap();
 
@@ -36,6 +34,7 @@ fn print_logo(output: &mut Output) {
  | |/ _` | '_ \\|_  / _` | '_ \\ / _ \\ / _ \\| __|\r
  | | (_| | | | |/ / (_| | |_) | (_) | (_) | |_ \r
  |_|\\__,_|_| |_/___\\__,_|_.__/ \\___/ \\___/ \\__|\r
+\r
 "
         ))
         .unwrap();
@@ -103,13 +102,18 @@ fn main(handle: Handle, mut system_table: SystemTable<Boot>) -> Status {
 
     let boot_services = system_table.boot_services();
 
-    let image_file = image_file(boot_services, handle).unwrap();
+    {
+        let mut image_file = image_file(boot_services, handle).unwrap();
+        let image_data = read_all(&mut image_file).unwrap();
+
+        if let Some(data) = pe_section(&image_data, ".osrel") {
+            info!("osrel = {}", core::str::from_utf8(data).unwrap_or("???"))
+        }
+    }
 
     let mut file_system = boot_services.get_image_file_system(handle).unwrap();
     let mut root = file_system.open_volume().unwrap();
 
-    debug!("Found root");
-
     let mut file = root
         .open(cstr16!("linux.efi"), FileMode::Read, FileAttribute::empty())
         .unwrap()

rust/lanzaboote/src/pe_section.rs

@@ -0,0 +1,14 @@
+pub fn pe_section<'a>(file_data: &'a [u8], section_name: &str) -> Option<&'a [u8]> {
+    let pe_binary = goblin::pe::PE::parse(file_data).ok()?;
+
+    pe_binary
+        .sections
+        .iter()
+        .find(|s| s.name().unwrap() == section_name)
+        .and_then(|s| {
+            let section_start: usize = s.pointer_to_raw_data.try_into().ok()?;
+            let section_end: usize = section_start + usize::try_from(s.size_of_raw_data).ok()?;
+
+            Some(&file_data[section_start..section_end])
+        })
+}