// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.
use std::borrow::Cow;
use std::collections::BTreeMap;
use std::collections::HashMap;
use std::collections::VecDeque;
use std::env::current_exe;
use std::ffi::OsString;
use std::fs;
use std::fs::File;
use std::future::Future;
use std::io::Read;
use std::io::Seek;
use std::io::SeekFrom;
use std::io::Write;
use std::path::Path;
use std::path::PathBuf;
use std::process::Command;
use deno_ast::ModuleSpecifier;
use deno_config::workspace::PackageJsonDepResolution;
use deno_config::workspace::ResolverWorkspaceJsrPackage;
use deno_config::workspace::Workspace;
use deno_config::workspace::WorkspaceResolver;
use deno_core::anyhow::bail;
use deno_core::anyhow::Context;
use deno_core::error::AnyError;
use deno_core::futures::io::AllowStdIo;
use deno_core::futures::AsyncReadExt;
use deno_core::futures::AsyncSeekExt;
use deno_core::serde_json;
use deno_core::url::Url;
use deno_npm::NpmSystemInfo;
use deno_runtime::deno_node::PackageJson;
use deno_semver::npm::NpmVersionReqParseError;
use deno_semver::package::PackageReq;
use deno_semver::Version;
use deno_semver::VersionReqSpecifierParseError;
use eszip::EszipRelativeFileBaseUrl;
use indexmap::IndexMap;
use log::Level;
use serde::Deserialize;
use serde::Serialize;
use crate::args::CaData;
use crate::args::CliOptions;
use crate::args::CompileFlags;
use crate::args::NpmInstallDepsProvider;
use crate::args::PermissionFlags;
use crate::args::UnstableConfig;
use crate::cache::DenoDir;
use crate::file_fetcher::FileFetcher;
use crate::http_util::HttpClientProvider;
use crate::npm::CliNpmResolver;
use crate::npm::InnerCliNpmResolverRef;
use crate::shared::ReleaseChannel;
use crate::standalone::virtual_fs::VfsEntry;
use crate::util::archive;
use crate::util::fs::canonicalize_path_maybe_not_exists;
use crate::util::progress_bar::ProgressBar;
use crate::util::progress_bar::ProgressBarStyle;
use super::virtual_fs::FileBackedVfs;
use super::virtual_fs::VfsBuilder;
use super::virtual_fs::VfsRoot;
use super::virtual_fs::VirtualDirectory;
const MAGIC_TRAILER: &[u8; 8] = b"d3n0l4nd";
#[derive(Deserialize, Serialize)]
pub enum NodeModules {
Managed {
/// Relative path for the node_modules directory in the vfs.
node_modules_dir: Option<String>,
},
Byonm {
root_node_modules_dir: Option<String>,
},
}
#[derive(Deserialize, Serialize)]
pub struct SerializedWorkspaceResolverImportMap {
pub specifier: String,
pub json: String,
}
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub struct SerializedResolverWorkspaceJsrPackage {
pub relative_base: String,
pub name: String,
pub version: Option<Version>,
pub exports: IndexMap<String, String>,
}
#[derive(Deserialize, Serialize)]
pub struct SerializedWorkspaceResolver {
pub import_map: Option<SerializedWorkspaceResolverImportMap>,
pub jsr_pkgs: Vec<SerializedResolverWorkspaceJsrPackage>,
pub package_jsons: BTreeMap<String, serde_json::Value>,
pub pkg_json_resolution: PackageJsonDepResolution,
}
// Note: Don't use hashmaps/hashsets. Ensure the serialization
// is deterministic.
#[derive(Deserialize, Serialize)]
pub struct Metadata {
pub argv: Vec<String>,
pub seed: Option<u64>,
pub permissions: PermissionFlags,
pub location: Option<Url>,
pub v8_flags: Vec<String>,
pub log_level: Option<Level>,
pub ca_stores: Option<Vec<String>>,
pub ca_data: Option<Vec<u8>>,
pub unsafely_ignore_certificate_errors: Option<Vec<String>>,
pub env_vars_from_env_file: IndexMap<String, String>,
pub workspace_resolver: SerializedWorkspaceResolver,
pub entrypoint_key: String,
pub node_modules: Option<NodeModules>,
pub unstable_config: UnstableConfig,
}
pub fn load_npm_vfs(root_dir_path: PathBuf) -> Result<FileBackedVfs, AnyError> {
let data = libsui::find_section("d3n0l4nd").unwrap();
// We do the first part sync so it can complete quickly
let trailer: [u8; TRAILER_SIZE] = data[0..TRAILER_SIZE].try_into().unwrap();
let trailer = match Trailer::parse(&trailer)? {
None => panic!("Could not find trailer"),
Some(trailer) => trailer,
};
let data = &data[TRAILER_SIZE..];
let vfs_data =
&data[trailer.npm_vfs_pos as usize..trailer.npm_files_pos as usize];
let mut dir: VirtualDirectory = serde_json::from_slice(vfs_data)?;
// align the name of the directory with the root dir
dir.name = root_dir_path
.file_name()
.unwrap()
.to_string_lossy()
.to_string();
let fs_root = VfsRoot {
dir,
root_path: root_dir_path,
start_file_offset: trailer.npm_files_pos,
};
Ok(FileBackedVfs::new(data.to_vec(), fs_root))
}
fn write_binary_bytes(
mut file_writer: File,
original_bin: Vec<u8>,
metadata: &Metadata,
eszip: eszip::EszipV2,
npm_vfs: Option<&VirtualDirectory>,
npm_files: &Vec<Vec<u8>>,
compile_flags: &CompileFlags,
) -> Result<(), AnyError> {
let metadata = serde_json::to_string(metadata)?.as_bytes().to_vec();
let npm_vfs = serde_json::to_string(&npm_vfs)?.as_bytes().to_vec();
let eszip_archive = eszip.into_bytes();
let mut writer = Vec::new();
// write the trailer, which includes the positions
// of the data blocks in the file
writer.write_all(&{
let metadata_pos = eszip_archive.len() as u64;
let npm_vfs_pos = metadata_pos + (metadata.len() as u64);
let npm_files_pos = npm_vfs_pos + (npm_vfs.len() as u64);
Trailer {
eszip_pos: 0,
metadata_pos,
npm_vfs_pos,
npm_files_pos,
}
.as_bytes()
})?;
writer.write_all(&eszip_archive)?;
writer.write_all(&metadata)?;
writer.write_all(&npm_vfs)?;
for file in npm_files {
writer.write_all(file)?;
}
let target = compile_flags.resolve_target();
if target.contains("linux") {
libsui::Elf::new(&original_bin).append(
"d3n0l4nd",
&writer,
&mut file_writer,
)?;
} else if target.contains("windows") {
let mut pe = libsui::PortableExecutable::from(&original_bin)?;
if let Some(icon) = compile_flags.icon.as_ref() {
let icon = std::fs::read(icon)?;
pe = pe.set_icon(&icon)?;
}
pe.write_resource("d3n0l4nd", writer)?
.build(&mut file_writer)?;
} else if target.contains("darwin") {
libsui::Macho::from(original_bin)?
.write_section("d3n0l4nd", writer)?
.build_and_sign(&mut file_writer)?;
}
Ok(())
}
pub fn is_standalone_binary(exe_path: &Path) -> bool {
let Ok(data) = std::fs::read(exe_path) else {
return false;
};
libsui::utils::is_elf(&data)
|| libsui::utils::is_pe(&data)
|| libsui::utils::is_macho(&data)
}
/// This function will try to run this binary as a standalone binary
/// produced by `deno compile`. It determines if this is a standalone
/// binary by skipping over the trailer width at the end of the file,
/// then checking for the magic trailer string `d3n0l4nd`. If found,
/// the bundle is executed. If not, this function exits with `Ok(None)`.
pub fn extract_standalone(
cli_args: Cow<Vec<OsString>>,
) -> Result<
Option<impl Future<Output = Result<(Metadata, eszip::EszipV2), AnyError>>>,
AnyError,
> {
let Some(data) = libsui::find_section("d3n0l4nd") else {
return Ok(None);
};
// We do the first part sync so it can complete quickly
let trailer = match Trailer::parse(&data[0..TRAILER_SIZE])? {
None => return Ok(None),
Some(trailer) => trailer,
};
let cli_args = cli_args.into_owned();
// If we have an eszip, read it out
Ok(Some(async move {
let bufreader =
deno_core::futures::io::BufReader::new(&data[TRAILER_SIZE..]);
let (eszip, loader) = eszip::EszipV2::parse(bufreader)
.await
.context("Failed to parse eszip header")?;
let bufreader = loader.await.context("Failed to parse eszip archive")?;
let mut metadata = String::new();
bufreader
.take(trailer.metadata_len())
.read_to_string(&mut metadata)
.await
.context("Failed to read metadata from the current executable")?;
let mut metadata: Metadata = serde_json::from_str(&metadata).unwrap();
metadata.argv.reserve(cli_args.len() - 1);
for arg in cli_args.into_iter().skip(1) {
metadata.argv.push(arg.into_string().unwrap());
}
Ok((metadata, eszip))
}))
}
const TRAILER_SIZE: usize = std::mem::size_of::<Trailer>() + 8; // 8 bytes for the magic trailer string
struct Trailer {
eszip_pos: u64,
metadata_pos: u64,
npm_vfs_pos: u64,
npm_files_pos: u64,
}
impl Trailer {
pub fn parse(trailer: &[u8]) -> Result<Option<Trailer>, AnyError> {
let (magic_trailer, rest) = trailer.split_at(8);
if magic_trailer != MAGIC_TRAILER {
return Ok(None);
}
let (eszip_archive_pos, rest) = rest.split_at(8);
let (metadata_pos, rest) = rest.split_at(8);
let (npm_vfs_pos, npm_files_pos) = rest.split_at(8);
let eszip_archive_pos = u64_from_bytes(eszip_archive_pos)?;
let metadata_pos = u64_from_bytes(metadata_pos)?;
let npm_vfs_pos = u64_from_bytes(npm_vfs_pos)?;
let npm_files_pos = u64_from_bytes(npm_files_pos)?;
Ok(Some(Trailer {
eszip_pos: eszip_archive_pos,
metadata_pos,
npm_vfs_pos,
npm_files_pos,
}))
}
pub fn metadata_len(&self) -> u64 {
self.npm_vfs_pos - self.metadata_pos
}
pub fn npm_vfs_len(&self) -> u64 {
self.npm_files_pos - self.npm_vfs_pos
}
pub fn as_bytes(&self) -> Vec<u8> {
let mut trailer = MAGIC_TRAILER.to_vec();
trailer.write_all(&self.eszip_pos.to_be_bytes()).unwrap();
trailer.write_all(&self.metadata_pos.to_be_bytes()).unwrap();
trailer.write_all(&self.npm_vfs_pos.to_be_bytes()).unwrap();
trailer
.write_all(&self.npm_files_pos.to_be_bytes())
.unwrap();
trailer
}
}
fn u64_from_bytes(arr: &[u8]) -> Result<u64, AnyError> {
let fixed_arr: &[u8; 8] = arr
.try_into()
.context("Failed to convert the buffer into a fixed-size array")?;
Ok(u64::from_be_bytes(*fixed_arr))
}
pub struct DenoCompileBinaryWriter<'a> {
deno_dir: &'a DenoDir,
file_fetcher: &'a FileFetcher,
http_client_provider: &'a HttpClientProvider,
npm_resolver: &'a dyn CliNpmResolver,
workspace_resolver: &'a WorkspaceResolver,
npm_system_info: NpmSystemInfo,
}
impl<'a> DenoCompileBinaryWriter<'a> {
#[allow(clippy::too_many_arguments)]
pub fn new(
deno_dir: &'a DenoDir,
file_fetcher: &'a FileFetcher,
http_client_provider: &'a HttpClientProvider,
npm_resolver: &'a dyn CliNpmResolver,
workspace_resolver: &'a WorkspaceResolver,
npm_system_info: NpmSystemInfo,
) -> Self {
Self {
deno_dir,
file_fetcher,
http_client_provider,
npm_resolver,
workspace_resolver,
npm_system_info,
}
}
pub async fn write_bin(
&self,
writer: File,
eszip: eszip::EszipV2,
root_dir_url: EszipRelativeFileBaseUrl<'_>,
entrypoint: &ModuleSpecifier,
compile_flags: &CompileFlags,
cli_options: &CliOptions,
) -> Result<(), AnyError> {
// Select base binary based on target
let mut original_binary = self.get_base_binary(compile_flags).await?;
if compile_flags.no_terminal {
let target = compile_flags.resolve_target();
if !target.contains("windows") {
bail!(
"The `--no-terminal` flag is only available when targeting Windows (current: {})",
target,
)
}
set_windows_binary_to_gui(&mut original_binary)?;
}
if compile_flags.icon.is_some() {
let target = compile_flags.resolve_target();
if !target.contains("windows") {
bail!(
"The `--icon` flag is only available when targeting Windows (current: {})",
target,
)
}
}
self.write_standalone_binary(
writer,
original_binary,
eszip,
root_dir_url,
entrypoint,
cli_options,
compile_flags,
)
}
async fn get_base_binary(
&self,
compile_flags: &CompileFlags,
) -> Result<Vec<u8>, AnyError> {
// Used for testing.
//
// Phase 2 of the 'min sized' deno compile RFC talks
// about adding this as a flag.
if let Some(path) = std::env::var_os("DENORT_BIN") {
return std::fs::read(&path).with_context(|| {
format!("Could not find denort at '{}'", path.to_string_lossy())
});
}
let target = compile_flags.resolve_target();
let binary_name = format!("denort-{target}.zip");
let binary_path_suffix =
match crate::version::DENO_VERSION_INFO.release_channel {
ReleaseChannel::Canary => {
format!(
"canary/{}/{}",
crate::version::DENO_VERSION_INFO.git_hash,
binary_name
)
}
ReleaseChannel::Stable => {
format!("release/v{}/{}", env!("CARGO_PKG_VERSION"), binary_name)
}
_ => bail!(
"`deno compile` current doesn't support {} release channel",
crate::version::DENO_VERSION_INFO.release_channel.name()
),
};
let download_directory = self.deno_dir.dl_folder_path();
let binary_path = download_directory.join(&binary_path_suffix);
if !binary_path.exists() {
self
.download_base_binary(&download_directory, &binary_path_suffix)
.await?;
}
let archive_data = std::fs::read(binary_path)?;
let temp_dir = tempfile::TempDir::new()?;
let base_binary_path = archive::unpack_into_dir(archive::UnpackArgs {
exe_name: "denort",
archive_name: &binary_name,
archive_data: &archive_data,
is_windows: target.contains("windows"),
dest_path: temp_dir.path(),
})?;
let base_binary = std::fs::read(base_binary_path)?;
drop(temp_dir); // delete the temp dir
Ok(base_binary)
}
async fn download_base_binary(
&self,
output_directory: &Path,
binary_path_suffix: &str,
) -> Result<(), AnyError> {
let download_url = format!("https://dl.deno.land/{binary_path_suffix}");
let maybe_bytes = {
let progress_bars = ProgressBar::new(ProgressBarStyle::DownloadBars);
let progress = progress_bars.update(&download_url);
self
.http_client_provider
.get_or_create()?
.download_with_progress(download_url.parse()?, None, &progress)
.await?
};
let bytes = match maybe_bytes {
Some(bytes) => bytes,
None => {
log::info!("Download could not be found, aborting");
std::process::exit(1)
}
};
std::fs::create_dir_all(output_directory)?;
let output_path = output_directory.join(binary_path_suffix);
std::fs::create_dir_all(output_path.parent().unwrap())?;
tokio::fs::write(output_path, bytes).await?;
Ok(())
}
/// This functions creates a standalone deno binary by appending a bundle
/// and magic trailer to the currently executing binary.
#[allow(clippy::too_many_arguments)]
fn write_standalone_binary(
&self,
writer: File,
original_bin: Vec<u8>,
mut eszip: eszip::EszipV2,
root_dir_url: EszipRelativeFileBaseUrl<'_>,
entrypoint: &ModuleSpecifier,
cli_options: &CliOptions,
compile_flags: &CompileFlags,
) -> Result<(), AnyError> {
let ca_data = match cli_options.ca_data() {
Some(CaData::File(ca_file)) => Some(
std::fs::read(ca_file)
.with_context(|| format!("Reading: {ca_file}"))?,
),
Some(CaData::Bytes(bytes)) => Some(bytes.clone()),
None => None,
};
let root_path = root_dir_url.inner().to_file_path().unwrap();
let (npm_vfs, npm_files, node_modules) = match self.npm_resolver.as_inner()
{
InnerCliNpmResolverRef::Managed(managed) => {
let snapshot =
managed.serialized_valid_snapshot_for_system(&self.npm_system_info);
if !snapshot.as_serialized().packages.is_empty() {
let (root_dir, files) = self
.build_vfs(&root_path, cli_options)?
.into_dir_and_files();
eszip.add_npm_snapshot(snapshot);
(
Some(root_dir),
files,
Some(NodeModules::Managed {
node_modules_dir: self.npm_resolver.root_node_modules_path().map(
|path| {
root_dir_url
.specifier_key(
&ModuleSpecifier::from_directory_path(path).unwrap(),
)
.into_owned()
},
),
}),
)
} else {
(None, Vec::new(), None)
}
}
InnerCliNpmResolverRef::Byonm(resolver) => {
let (root_dir, files) = self
.build_vfs(&root_path, cli_options)?
.into_dir_and_files();
(
Some(root_dir),
files,
Some(NodeModules::Byonm {
root_node_modules_dir: resolver.root_node_modules_path().map(
|node_modules_dir| {
root_dir_url
.specifier_key(
&ModuleSpecifier::from_directory_path(node_modules_dir)
.unwrap(),
)
.into_owned()
},
),
}),
)
}
};
let env_vars_from_env_file = match cli_options.env_file_name() {
Some(env_filename) => {
log::info!("{} Environment variables from the file \"{}\" were embedded in the generated executable file", crate::colors::yellow("Warning"), env_filename);
get_file_env_vars(env_filename.to_string())?
}
None => Default::default(),
};
let metadata = Metadata {
argv: compile_flags.args.clone(),
seed: cli_options.seed(),
location: cli_options.location_flag().clone(),
permissions: cli_options.permission_flags().clone(),
v8_flags: cli_options.v8_flags().clone(),
unsafely_ignore_certificate_errors: cli_options
.unsafely_ignore_certificate_errors()
.clone(),
log_level: cli_options.log_level(),
ca_stores: cli_options.ca_stores().clone(),
ca_data,
env_vars_from_env_file,
entrypoint_key: root_dir_url.specifier_key(entrypoint).into_owned(),
workspace_resolver: SerializedWorkspaceResolver {
import_map: self.workspace_resolver.maybe_import_map().map(|i| {
SerializedWorkspaceResolverImportMap {
specifier: if i.base_url().scheme() == "file" {
root_dir_url.specifier_key(i.base_url()).into_owned()
} else {
// just make a remote url local
"deno.json".to_string()
},
json: i.to_json(),
}
}),
jsr_pkgs: self
.workspace_resolver
.jsr_packages()
.map(|pkg| SerializedResolverWorkspaceJsrPackage {
relative_base: root_dir_url.specifier_key(&pkg.base).into_owned(),
name: pkg.name.clone(),
version: pkg.version.clone(),
exports: pkg.exports.clone(),
})
.collect(),
package_jsons: self
.workspace_resolver
.package_jsons()
.map(|pkg_json| {
(
root_dir_url
.specifier_key(&pkg_json.specifier())
.into_owned(),
serde_json::to_value(pkg_json).unwrap(),
)
})
.collect(),
pkg_json_resolution: self.workspace_resolver.pkg_json_dep_resolution(),
},
node_modules,
unstable_config: UnstableConfig {
legacy_flag_enabled: cli_options.legacy_unstable_flag(),
bare_node_builtins: cli_options.unstable_bare_node_builtins(),
sloppy_imports: cli_options.unstable_sloppy_imports(),
features: cli_options.unstable_features(),
},
};
write_binary_bytes(
writer,
original_bin,
&metadata,
eszip,
npm_vfs.as_ref(),
&npm_files,
compile_flags,
)
}
fn build_vfs(
&self,
root_path: &Path,
cli_options: &CliOptions,
) -> Result<VfsBuilder, AnyError> {
fn maybe_warn_different_system(system_info: &NpmSystemInfo) {
if system_info != &NpmSystemInfo::default() {
log::warn!("{} The node_modules directory may be incompatible with the target system.", crate::colors::yellow("Warning"));
}
}
match self.npm_resolver.as_inner() {
InnerCliNpmResolverRef::Managed(npm_resolver) => {
if let Some(node_modules_path) = npm_resolver.root_node_modules_path() {
maybe_warn_different_system(&self.npm_system_info);
let mut builder = VfsBuilder::new(root_path.to_path_buf())?;
builder.add_dir_recursive(node_modules_path)?;
Ok(builder)
} else {
// DO NOT include the user's registry url as it may contain credentials,
// but also don't make this dependent on the registry url
let root_path = npm_resolver.global_cache_root_folder();
let mut builder = VfsBuilder::new(root_path)?;
let mut packages =
npm_resolver.all_system_packages(&self.npm_system_info);
packages.sort_by(|a, b| a.id.cmp(&b.id)); // determinism
for package in packages {
let folder =
npm_resolver.resolve_pkg_folder_from_pkg_id(&package.id)?;
builder.add_dir_recursive(&folder)?;
}
// Flatten all the registries folders into a single "node_modules/localhost" folder
// that will be used by denort when loading the npm cache. This avoids us exposing
// the user's private registry information and means we don't have to bother
// serializing all the different registry config into the binary.
builder.with_root_dir(|root_dir| {
root_dir.name = "node_modules".to_string();
let mut new_entries = Vec::with_capacity(root_dir.entries.len());
let mut localhost_entries = IndexMap::new();
for entry in std::mem::take(&mut root_dir.entries) {
match entry {
VfsEntry::Dir(dir) => {
for entry in dir.entries {
log::debug!(
"Flattening {} into node_modules",
entry.name()
);
if let Some(existing) =
localhost_entries.insert(entry.name().to_string(), entry)
{
panic!(
"Unhandled scenario where a duplicate entry was found: {:?}",
existing
);
}
}
}
VfsEntry::File(_) | VfsEntry::Symlink(_) => {
new_entries.push(entry);
}
}
}
new_entries.push(VfsEntry::Dir(VirtualDirectory {
name: "localhost".to_string(),
entries: localhost_entries.into_iter().map(|(_, v)| v).collect(),
}));
// needs to be sorted by name
new_entries.sort_by(|a, b| a.name().cmp(b.name()));
root_dir.entries = new_entries;
});
Ok(builder)
}
}
InnerCliNpmResolverRef::Byonm(_) => {
maybe_warn_different_system(&self.npm_system_info);
let mut builder = VfsBuilder::new(root_path.to_path_buf())?;
for pkg_json in cli_options.workspace().package_jsons() {
builder.add_file_at_path(&pkg_json.path)?;
}
// traverse and add all the node_modules directories in the workspace
let mut pending_dirs = VecDeque::new();
pending_dirs.push_back(
cli_options.workspace().root_dir().to_file_path().unwrap(),
);
while let Some(pending_dir) = pending_dirs.pop_front() {
let mut entries = fs::read_dir(&pending_dir)
.with_context(|| {
format!("Failed reading: {}", pending_dir.display())
})?
.collect::<Result<Vec<_>, _>>()?;
entries.sort_by_cached_key(|entry| entry.file_name()); // determinism
for entry in entries {
let path = entry.path();
if !path.is_dir() {
continue;
}
if path.ends_with("node_modules") {
builder.add_dir_recursive(&path)?;
} else {
pending_dirs.push_back(path);
}
}
}
Ok(builder)
}
}
}
}
/// This function returns the environment variables specified
/// in the passed environment file.
fn get_file_env_vars(
filename: String,
) -> Result<IndexMap<String, String>, dotenvy::Error> {
let mut file_env_vars = IndexMap::new();
for item in dotenvy::from_filename_iter(filename)? {
let Ok((key, val)) = item else {
continue; // this failure will be warned about on load
};
file_env_vars.insert(key, val);
}
Ok(file_env_vars)
}
/// This function sets the subsystem field in the PE header to 2 (GUI subsystem)
/// For more information about the PE header: https://learn.microsoft.com/en-us/windows/win32/debug/pe-format
fn set_windows_binary_to_gui(bin: &mut [u8]) -> Result<(), AnyError> {
// Get the PE header offset located in an i32 found at offset 60
// See: https://learn.microsoft.com/en-us/windows/win32/debug/pe-format#ms-dos-stub-image-only
let start_pe = u32::from_le_bytes((bin[60..64]).try_into()?);
// Get image type (PE32 or PE32+) indicates whether the binary is 32 or 64 bit
// The used offset and size values can be found here:
// https://learn.microsoft.com/en-us/windows/win32/debug/pe-format#optional-header-image-only
let start_32 = start_pe as usize + 28;
let magic_32 =
u16::from_le_bytes(bin[(start_32)..(start_32 + 2)].try_into()?);
let start_64 = start_pe as usize + 24;
let magic_64 =
u16::from_le_bytes(bin[(start_64)..(start_64 + 2)].try_into()?);
// Take the standard fields size for the current architecture (32 or 64 bit)
// This is the ofset for the Windows-Specific fields
let standard_fields_size = if magic_32 == 0x10b {
28
} else if magic_64 == 0x20b {
24
} else {
bail!("Could not find a matching magic field in the PE header")
};
// Set the subsystem field (offset 68) to 2 (GUI subsystem)
// For all possible options, see: https://learn.microsoft.com/en-us/windows/win32/debug/pe-format#optional-header-windows-specific-fields-image-only
let subsystem_offset = 68;
let subsystem_start =
start_pe as usize + standard_fields_size + subsystem_offset;
let subsystem: u16 = 2;
bin[(subsystem_start)..(subsystem_start + 2)]
.copy_from_slice(&subsystem.to_le_bytes());
Ok(())
}