-
Notifications
You must be signed in to change notification settings - Fork 42
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Split dm-verify hash tree logic out of avb module
* Refactor hash tree computation to work on a preallocated hash tree buffer. This makes it possible to partially update a hash tree, which is now supported. * Add new subcommands for working with hash trees. There's no standard header format for dm-verity information, so these commands write hash tree files with a custom header. The commands are not really useful outside of debugging avbroot's hash tree implementation. Using AVB was considered, but it has no support for the hash tree data living in a separate file from the input. If other parties agree on a standard header in the future, avbroot will switch to that format. * Add tests for the hash tree implementation. Signed-off-by: Andrew Gunnerson <[email protected]>
- Loading branch information
1 parent
ce43b3c
commit 7ea8e8f
Showing
9 changed files
with
1,020 additions
and
203 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,176 @@ | ||
| /* | ||
| * SPDX-FileCopyrightText: 2023 Andrew Gunnerson | ||
| * SPDX-License-Identifier: GPL-3.0-only | ||
| */ | ||
|
|
||
| use std::{ | ||
| fs::{File, OpenOptions}, | ||
| io::{BufReader, BufWriter, Write}, | ||
| path::{Path, PathBuf}, | ||
| sync::atomic::AtomicBool, | ||
| }; | ||
|
|
||
| use anyhow::{Context, Result}; | ||
| use clap::{Parser, Subcommand}; | ||
|
|
||
| use crate::{ | ||
| format::hashtree::HashTreeImage, | ||
| stream::{FromReader, PSeekFile, ToWriter}, | ||
| }; | ||
|
|
||
| fn open_input(path: &Path, rw: bool) -> Result<PSeekFile> { | ||
| OpenOptions::new() | ||
| .read(true) | ||
| .write(rw) | ||
| .open(path) | ||
| .map(PSeekFile::new) | ||
| .with_context(|| format!("Failed to open file: {path:?}")) | ||
| } | ||
|
|
||
| fn read_hash_tree(path: &Path) -> Result<HashTreeImage> { | ||
| let reader = File::open(path) | ||
| .map(BufReader::new) | ||
| .with_context(|| format!("Failed to open for reading: {path:?}"))?; | ||
| let hash_tree = HashTreeImage::from_reader(reader) | ||
| .with_context(|| format!("Failed to read hash tree data: {path:?}"))?; | ||
|
|
||
| Ok(hash_tree) | ||
| } | ||
|
|
||
| fn write_hash_tree(path: &Path, hash_tree: &HashTreeImage) -> Result<()> { | ||
| let mut writer = File::create(path) | ||
| .map(BufWriter::new) | ||
| .with_context(|| format!("Failed to open for writing: {path:?}"))?; | ||
| hash_tree | ||
| .to_writer(&mut writer) | ||
| .with_context(|| format!("Failed to write hash tree data: {path:?}"))?; | ||
| writer | ||
| .flush() | ||
| .with_context(|| format!("Failed to flush hash tree data: {path:?}"))?; | ||
|
|
||
| Ok(()) | ||
| } | ||
|
|
||
| fn generate_subcommand(cli: &GenerateCli, cancel_signal: &AtomicBool) -> Result<()> { | ||
| let salt = hex::decode(&cli.salt).context("Invalid salt")?; | ||
| let input = open_input(&cli.input, false)?; | ||
|
|
||
| let hash_tree = | ||
| HashTreeImage::generate(&input, cli.block_size, &cli.algorithm, &salt, cancel_signal) | ||
| .context("Failed to generate hash tree data")?; | ||
|
|
||
| write_hash_tree(&cli.hash_tree, &hash_tree)?; | ||
|
|
||
| Ok(()) | ||
| } | ||
|
|
||
| fn update_subcommand(cli: &UpdateCli, cancel_signal: &AtomicBool) -> Result<()> { | ||
| let ranges = cli | ||
| .range | ||
| .chunks_exact(2) | ||
| .map(|w| w[0]..w[1]) | ||
| .collect::<Vec<_>>(); | ||
|
|
||
| let input = open_input(&cli.input, false)?; | ||
| let mut hash_tree = read_hash_tree(&cli.hash_tree)?; | ||
|
|
||
| hash_tree | ||
| .update(&input, &ranges, cancel_signal) | ||
| .context("Failed to update hash tree data")?; | ||
|
|
||
| write_hash_tree(&cli.hash_tree, &hash_tree)?; | ||
|
|
||
| Ok(()) | ||
| } | ||
|
|
||
| fn verify_subcommand(cli: &VerifyCli, cancel_signal: &AtomicBool) -> Result<()> { | ||
| let input = open_input(&cli.input, false)?; | ||
| let hash_tree = read_hash_tree(&cli.hash_tree)?; | ||
|
|
||
| hash_tree | ||
| .verify(&input, cancel_signal) | ||
| .context("Failed to verify data")?; | ||
|
|
||
| Ok(()) | ||
| } | ||
|
|
||
| pub fn hash_tree_main(cli: &HashTreeCli, cancel_signal: &AtomicBool) -> Result<()> { | ||
| match &cli.command { | ||
| HashTreeCommand::Generate(c) => generate_subcommand(c, cancel_signal), | ||
| HashTreeCommand::Update(c) => update_subcommand(c, cancel_signal), | ||
| HashTreeCommand::Verify(c) => verify_subcommand(c, cancel_signal), | ||
| } | ||
| } | ||
|
|
||
| /// Generate hash tree data for a file. | ||
| #[derive(Debug, Parser)] | ||
| struct GenerateCli { | ||
| /// Path to input data. | ||
| #[arg(short, long, value_name = "FILE", value_parser)] | ||
| input: PathBuf, | ||
|
|
||
| /// Path to output hash tree data. | ||
| #[arg(short = 'H', long, value_name = "FILE", value_parser)] | ||
| hash_tree: PathBuf, | ||
|
|
||
| /// Block size. | ||
| #[arg(short, long, value_name = "BYTES", default_value = "4096")] | ||
| block_size: u32, | ||
|
|
||
| /// Hash algorithm. | ||
| #[arg(short, long, value_name = "NAME", default_value = "sha256")] | ||
| algorithm: String, | ||
|
|
||
| /// Salt (in hex). | ||
| #[arg(short, long, value_name = "HEX", default_value = "")] | ||
| salt: String, | ||
| } | ||
|
|
||
| /// Update hash tree data after a file is modified. | ||
| #[derive(Debug, Parser)] | ||
| struct UpdateCli { | ||
| /// Path to input data. | ||
| #[arg(short, long, value_name = "FILE", value_parser)] | ||
| input: PathBuf, | ||
|
|
||
| /// Path to hash tree data. | ||
| /// | ||
| /// The file will be modified in place. | ||
| #[arg(short = 'H', long, value_name = "FILE", value_parser)] | ||
| hash_tree: PathBuf, | ||
|
|
||
| /// Input file ranges that were updated. | ||
| /// | ||
| /// This is a half-open range and can be specified multiple times. | ||
| #[arg(short, long, value_names = ["START", "END"], num_args = 2)] | ||
| range: Vec<u64>, | ||
| } | ||
|
|
||
| /// Verify that a file contains no errors. | ||
| #[derive(Debug, Parser)] | ||
| struct VerifyCli { | ||
| /// Path to input data. | ||
| #[arg(short, long, value_name = "FILE", value_parser)] | ||
| input: PathBuf, | ||
|
|
||
| /// Path to input hash tree data. | ||
| #[arg(short = 'H', long, value_name = "FILE", value_parser)] | ||
| hash_tree: PathBuf, | ||
| } | ||
|
|
||
| #[derive(Debug, Subcommand)] | ||
| enum HashTreeCommand { | ||
| Generate(GenerateCli), | ||
| Update(UpdateCli), | ||
| Verify(VerifyCli), | ||
| } | ||
|
|
||
| /// Generate dm-verity hash tree data and verify files. | ||
| /// | ||
| /// These commands operate on a standard hash tree data prepended by a custom | ||
| /// header. | ||
| #[derive(Debug, Parser)] | ||
| pub struct HashTreeCli { | ||
| #[command(subcommand)] | ||
| command: HashTreeCommand, | ||
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.