3 fn check_for_key(key_name: &std::ffi::CStr) -> anyhow::Result<bool> {
4 use bch_bindgen::keyutils::{self, keyctl_search};
5 let key_name = key_name.to_bytes_with_nul().as_ptr() as *const _;
6 let key_type = c_str!("logon");
8 let key_id = unsafe { keyctl_search(keyutils::KEY_SPEC_USER_KEYRING, key_type, key_name, 0) };
10 info!("Key has became avaiable");
12 } else if errno::errno().0 != libc::ENOKEY {
13 Err(crate::ErrnoError(errno::errno()).into())
19 fn wait_for_key(uuid: &uuid::Uuid) -> anyhow::Result<()> {
20 let key_name = std::ffi::CString::new(format!("bcachefs:{}", uuid)).unwrap();
22 if check_for_key(&key_name)? {
26 std::thread::sleep(std::time::Duration::from_secs(1));
30 const BCH_KEY_MAGIC: &str = "bch**key";
31 use crate::filesystem::FileSystem;
32 fn ask_for_key(fs: &FileSystem) -> anyhow::Result<()> {
34 use byteorder::{LittleEndian, ReadBytesExt};
35 use bch_bindgen::bcachefs::{self, bch2_chacha_encrypt_key, bch_encrypted_key, bch_key};
36 use std::os::raw::c_char;
38 let key_name = std::ffi::CString::new(format!("bcachefs:{}", fs.uuid())).unwrap();
39 if check_for_key(&key_name)? {
43 let bch_key_magic = BCH_KEY_MAGIC.as_bytes().read_u64::<LittleEndian>().unwrap();
44 let crypt = fs.sb().sb().crypt().unwrap();
45 let pass = rpassword::read_password_from_tty(Some("Enter passphrase: "))?;
46 let pass = std::ffi::CString::new(pass.trim_end())?; // bind to keep the CString alive
47 let mut output: bch_key = unsafe {
48 bcachefs::derive_passphrase(
49 crypt as *const _ as *mut _,
50 pass.as_c_str().to_bytes_with_nul().as_ptr() as *const _,
54 let mut key = crypt.key().clone();
56 bch2_chacha_encrypt_key(
57 &mut output as *mut _,
59 &mut key as *mut _ as *mut _,
60 std::mem::size_of::<bch_encrypted_key>() as u64,
64 Err(anyhow!("chacha decryption failure"))
65 } else if key.magic != bch_key_magic {
66 Err(anyhow!("failed to verify the password"))
68 let key_type = c_str!("logon");
70 bch_bindgen::keyutils::add_key(
72 key_name.as_c_str().to_bytes_with_nul() as *const _ as *const c_char,
73 &output as *const _ as *const _,
74 std::mem::size_of::<bch_key>() as u64,
75 bch_bindgen::keyutils::KEY_SPEC_USER_KEYRING,
79 Err(anyhow!("failed to add key to keyring: {}", errno::errno()))
86 #[tracing_attributes::instrument]
87 pub fn prepare_key(fs: &FileSystem, password: crate::KeyLocation) -> anyhow::Result<()> {
88 use crate::KeyLocation::*;
91 tracing::info!(msg = "checking if key exists for filesystem");
93 Fail => Err(anyhow!("no key available")),
94 Wait => Ok(wait_for_key(fs.uuid())?),
95 Ask => ask_for_key(fs),