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tape: add hardware encryption key managenent api

This commit is contained in:
Dietmar Maurer 2021-01-18 07:16:06 +01:00
parent 4e9cc3e97c
commit d5a48b5ce4
15 changed files with 518 additions and 37 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
src/api2/config.rs
View File

@ -9,6 +9,7 @@ pub mod verify;
pub mod drive;
pub mod changer;
pub mod media_pool;
pub mod tape_encryption_keys;
const SUBDIRS: SubdirMap = &[
("access", &access::ROUTER),
@ -18,6 +19,7 @@ const SUBDIRS: SubdirMap = &[
("media-pool", &media_pool::ROUTER),
("remote", &remote::ROUTER),
("sync", &sync::ROUTER),
("tape-encryption-keys", &tape_encryption_keys::ROUTER),
("verify", &verify::ROUTER),
];

166
src/api2/config/tape_encryption_keys.rs Normal file
View File

@ -0,0 +1,166 @@
use anyhow::{bail, Error};
use serde_json::Value;
use proxmox::{
api::{
api,
ApiMethod,
Router,
RpcEnvironment,
},
tools::fs::open_file_locked,
};
use crate::{
config::{
tape_encryption_keys::{
TAPE_KEYS_LOCKFILE,
EncryptionKeyInfo,
load_keys,
save_keys,
},
},
api2::types::{
TAPE_ENCRYPTION_KEY_FINGERPRINT_SCHEMA,
PROXMOX_CONFIG_DIGEST_SCHEMA,
TapeKeyMetadata,
},
backup::Fingerprint,
tools::format::as_fingerprint,
};
#[api(
protected: true,
input: {
properties: {},
},
returns: {
description: "The list of tape encryption keys (with config digest).",
type: Array,
items: { type: TapeKeyMetadata },
},
)]
/// List existing keys
pub fn list_keys(
_param: Value,
_info: &ApiMethod,
mut rpcenv: &mut dyn RpcEnvironment,
) -> Result<Vec<TapeKeyMetadata>, Error> {
let (key_map, digest) = load_keys()?;
let mut list = Vec::new();
for (_fingerprint, item) in key_map {
list.push(TapeKeyMetadata {
hint: item.hint,
fingerprint: as_fingerprint(item.fingerprint.bytes()),
});
}
rpcenv["digest"] = proxmox::tools::digest_to_hex(&digest).into();
Ok(list)
}
#[api(
protected: true,
input: {
properties: {
password: {
description: "A secret password.",
min_length: 5,
},
hint: {
description: "Password restore hint",
min_length: 1,
},
},
},
)]
/// Create a new encryption key
pub fn create_key(
password: String,
hint: String,
_rpcenv: &mut dyn RpcEnvironment
) -> Result<Fingerprint, Error> {
let key = openssl::sha::sha256(password.as_bytes()); // fixme: better KDF ??
let item = EncryptionKeyInfo::new(&key, hint);
let _lock = open_file_locked(
TAPE_KEYS_LOCKFILE,
std::time::Duration::new(10, 0),
true,
)?;
let (mut key_map, _) = load_keys()?;
let fingerprint = item.fingerprint.clone();
if let Some(_) = key_map.get(&fingerprint) {
bail!("encryption key '{}' already exists.", fingerprint);
}
key_map.insert(fingerprint.clone(), item);
save_keys(key_map)?;
Ok(fingerprint)
}
#[api(
protected: true,
input: {
properties: {
fingerprint: {
schema: TAPE_ENCRYPTION_KEY_FINGERPRINT_SCHEMA,
},
digest: {
optional: true,
schema: PROXMOX_CONFIG_DIGEST_SCHEMA,
},
},
},
)]
/// Remove a encryption key from the database
///
/// Please note that you can no longer access tapes using this key.
pub fn delete_key(
fingerprint: Fingerprint,
digest: Option<String>,
_rpcenv: &mut dyn RpcEnvironment,
) -> Result<(), Error> {
let _lock = open_file_locked(
TAPE_KEYS_LOCKFILE,
std::time::Duration::new(10, 0),
true,
)?;
let (mut key_map, expected_digest) = load_keys()?;
if let Some(ref digest) = digest {
let digest = proxmox::tools::hex_to_digest(digest)?;
crate::tools::detect_modified_configuration_file(&digest, &expected_digest)?;
}
match key_map.get(&fingerprint) {
Some(_) => { key_map.remove(&fingerprint); },
None => bail!("tape encryption key '{}' does not exist.", fingerprint),
}
save_keys(key_map)?;
Ok(())
}
const ITEM_ROUTER: Router = Router::new()
//.get(&API_METHOD_READ_KEY_METADATA)
//.put(&API_METHOD_UPDATE_KEY_METADATA)
.delete(&API_METHOD_DELETE_KEY);
pub const ROUTER: Router = Router::new()
.get(&API_METHOD_LIST_KEYS)
.post(&API_METHOD_CREATE_KEY)
.match_all("fingerprint", &ITEM_ROUTER);

8
src/api2/tape/drive.rs
View File

@ -1,7 +1,7 @@
use std::path::Path;
use std::sync::Arc;
use anyhow::{bail, format_err, Error};
use anyhow::{bail, Error};
use serde_json::Value;
use proxmox::{
@ -880,8 +880,7 @@ pub fn cartridge_memory(drive: String) -> Result<Vec<MamAttribute>, Error> {
let (config, _digest) = config::drive::config()?;
let drive_config: LinuxTapeDrive = config.lookup("linux", &drive)?;
let mut handle = drive_config.open()
.map_err(|err| format_err!("open drive '{}' ({}) failed - {}", drive, drive_config.path, err))?;
let mut handle = drive_config.open()?;
handle.cartridge_memory()
}
@ -906,8 +905,7 @@ pub fn status(drive: String) -> Result<LinuxDriveAndMediaStatus, Error> {
let drive_config: LinuxTapeDrive = config.lookup("linux", &drive)?;
// Note: use open_linux_tape_device, because this also works if no medium loaded
let file = open_linux_tape_device(&drive_config.path)
.map_err(|err| format_err!("open drive '{}' ({}) failed - {}", drive, drive_config.path, err))?;
let file = open_linux_tape_device(&drive_config.path)?;
let mut handle = LinuxTapeHandle::new(file);

23
src/api2/types/mod.rs
View File

@ -77,7 +77,7 @@ const_regex!{
pub BACKUP_REPO_URL_REGEX = concat!(r"^^(?:(?:(", USER_ID_REGEX_STR!(), "|", APITOKEN_ID_REGEX_STR!(), ")@)?(", DNS_NAME!(), "|", IPRE_BRACKET!() ,"):)?(?:([0-9]{1,5}):)?(", PROXMOX_SAFE_ID_REGEX_STR!(), r")$");
pub CERT_FINGERPRINT_SHA256_REGEX = r"^(?:[0-9a-fA-F][0-9a-fA-F])(?::[0-9a-fA-F][0-9a-fA-F]){31}$";
pub FINGERPRINT_SHA256_REGEX = r"^(?:[0-9a-fA-F][0-9a-fA-F])(?::[0-9a-fA-F][0-9a-fA-F]){31}$";
pub ACL_PATH_REGEX = concat!(r"^(?:/|", r"(?:/", PROXMOX_SAFE_ID_REGEX_STR!(), ")+", r")$");
@ -103,8 +103,8 @@ pub const IP_FORMAT: ApiStringFormat =
pub const PVE_CONFIG_DIGEST_FORMAT: ApiStringFormat =
ApiStringFormat::Pattern(&SHA256_HEX_REGEX);
pub const CERT_FINGERPRINT_SHA256_FORMAT: ApiStringFormat =
ApiStringFormat::Pattern(&CERT_FINGERPRINT_SHA256_REGEX);
pub const FINGERPRINT_SHA256_FORMAT: ApiStringFormat =
ApiStringFormat::Pattern(&FINGERPRINT_SHA256_REGEX);
pub const PROXMOX_SAFE_ID_FORMAT: ApiStringFormat =
ApiStringFormat::Pattern(&PROXMOX_SAFE_ID_REGEX);
@ -163,17 +163,22 @@ pub const PBS_PASSWORD_SCHEMA: Schema = StringSchema::new("User Password.")
pub const CERT_FINGERPRINT_SHA256_SCHEMA: Schema = StringSchema::new(
"X509 certificate fingerprint (sha256)."
)
.format(&CERT_FINGERPRINT_SHA256_FORMAT)
.format(&FINGERPRINT_SHA256_FORMAT)
.schema();
pub const PROXMOX_CONFIG_DIGEST_SCHEMA: Schema = StringSchema::new(r#"\
Prevent changes if current configuration file has different SHA256 digest.
This can be used to prevent concurrent modifications.
"#
pub const TAPE_ENCRYPTION_KEY_FINGERPRINT_SCHEMA: Schema = StringSchema::new(
"Tape encryption key fingerprint (sha256)."
)
.format(&PVE_CONFIG_DIGEST_FORMAT)
.format(&FINGERPRINT_SHA256_FORMAT)
.schema();
pub const PROXMOX_CONFIG_DIGEST_SCHEMA: Schema = StringSchema::new(
"Prevent changes if current configuration file has different \
SHA256 digest. This can be used to prevent concurrent \
modifications."
)
.format(&PVE_CONFIG_DIGEST_FORMAT) .schema();
pub const CHUNK_DIGEST_FORMAT: ApiStringFormat =
ApiStringFormat::Pattern(&SHA256_HEX_REGEX);

18
src/api2/types/tape/drive.rs
View File

@ -12,7 +12,8 @@ use proxmox::api::{
use crate::api2::types::{
PROXMOX_SAFE_ID_FORMAT,
CHANGER_NAME_SCHEMA,
};
CERT_FINGERPRINT_SHA256_SCHEMA,
};
pub const DRIVE_NAME_SCHEMA: Schema = StringSchema::new("Drive Identifier.")
.format(&PROXMOX_SAFE_ID_FORMAT)
@ -205,3 +206,18 @@ pub struct LinuxDriveAndMediaStatus {
#[serde(skip_serializing_if="Option::is_none")]
pub medium_passes: Option<u64>,
}
#[api(
properties: {
fingerprint: {
schema: CERT_FINGERPRINT_SHA256_SCHEMA,
},
},
)]
#[derive(Deserialize, Serialize)]
/// Hardware Encryption key Metadata
pub struct TapeKeyMetadata {
/// Password hint
pub hint: String,
pub fingerprint: String,
}

2
src/backup/crypt_config.rs
View File

@ -39,7 +39,7 @@ pub enum CryptMode {
SignOnly,
}
#[derive(Debug, Eq, PartialEq, Deserialize, Serialize)]
#[derive(Debug, Eq, PartialEq, Hash, Clone, Deserialize, Serialize)]
#[serde(transparent)]
/// 32-byte fingerprint, usually calculated with SHA256.
pub struct Fingerprint {

1
src/bin/proxmox-tape.rs
View File

@ -952,6 +952,7 @@ fn main() {
.insert("drive", drive_commands())
.insert("pool", pool_commands())
.insert("media", media_commands())
.insert("key", encryption_key_commands())
.insert(
"load-media",
CliCommand::new(&API_METHOD_LOAD_MEDIA)

70
src/bin/proxmox_tape/encryption_key.rs Normal file
View File

@ -0,0 +1,70 @@
use anyhow::Error;
use serde_json::Value;
use proxmox::{
api::{
api,
cli::*,
RpcEnvironment,
ApiHandler,
},
};
use proxmox_backup::{
api2::{
self,
},
config::tape_encryption_keys::complete_key_fingerprint,
};
pub fn encryption_key_commands() -> CommandLineInterface {
let cmd_def = CliCommandMap::new()
.insert("list", CliCommand::new(&API_METHOD_LIST_KEYS))
.insert(
"create",
CliCommand::new(&api2::config::tape_encryption_keys::API_METHOD_CREATE_KEY)
)
.insert(
"remove",
CliCommand::new(&api2::config::tape_encryption_keys::API_METHOD_DELETE_KEY)
.arg_param(&["fingerprint"])
.completion_cb("fingerprint", complete_key_fingerprint)
)
;
cmd_def.into()
}
#[api(
input: {
properties: {
"output-format": {
schema: OUTPUT_FORMAT,
optional: true,
},
},
},
)]
/// List keys
fn list_keys(
param: Value,
rpcenv: &mut dyn RpcEnvironment,
) -> Result<(), Error> {
let output_format = get_output_format(&param);
let info = &api2::config::tape_encryption_keys::API_METHOD_LIST_KEYS;
let mut data = match info.handler {
ApiHandler::Sync(handler) => (handler)(param, info, rpcenv)?,
_ => unreachable!(),
};
let options = default_table_format_options()
.column(ColumnConfig::new("fingerprint"))
.column(ColumnConfig::new("hint"))
;
format_and_print_result_full(&mut data, &info.returns, &output_format, &options);
Ok(())
}

3
src/bin/proxmox_tape/mod.rs
View File

@ -9,3 +9,6 @@ pub use pool::*;
mod media;
pub use media::*;
mod encryption_key;
pub use encryption_key::*;

56
src/bin/sg-tape-cmd.rs
View File

@ -21,9 +21,11 @@ use proxmox::{
use proxmox_backup::{
config,
backup::Fingerprint,
api2::types::{
LINUX_DRIVE_PATH_SCHEMA,
DRIVE_NAME_SCHEMA,
TAPE_ENCRYPTION_KEY_FINGERPRINT_SCHEMA,
LinuxTapeDrive,
},
tape::{
@ -42,8 +44,7 @@ fn get_tape_handle(param: &Value) -> Result<LinuxTapeHandle, Error> {
let (config, _digest) = config::drive::config()?;
let drive: LinuxTapeDrive = config.lookup("linux", &name)?;
eprintln!("using device {}", drive.path);
drive.open()
.map_err(|err| format_err!("open drive '{}' ({}) failed - {}", name, drive.path, err))?
drive.open()?
} else if let Some(device) = param["device"].as_str() {
eprintln!("using device {}", device);
LinuxTapeHandle::new(open_linux_tape_device(&device)?)
@ -57,8 +58,7 @@ fn get_tape_handle(param: &Value) -> Result<LinuxTapeHandle, Error> {
let (config, _digest) = config::drive::config()?;
let drive: LinuxTapeDrive = config.lookup("linux", &name)?;
eprintln!("using device {}", drive.path);
drive.open()
.map_err(|err| format_err!("open drive '{}' ({}) failed - {}", name, drive.path, err))?
drive.open()?
} else {
let (config, _digest) = config::drive::config()?;
@ -72,8 +72,7 @@ fn get_tape_handle(param: &Value) -> Result<LinuxTapeHandle, Error> {
let name = drive_names[0];
let drive: LinuxTapeDrive = config.lookup("linux", &name)?;
eprintln!("using device {}", drive.path);
drive.open()
.map_err(|err| format_err!("open drive '{}' ({}) failed - {}", name, drive.path, err))?
drive.open()?
} else {
bail!("no drive/device specified");
}
@ -187,6 +186,47 @@ fn tape_alert_flags(
Ok(())
}
#[api(
input: {
properties: {
fingerprint: {
schema: TAPE_ENCRYPTION_KEY_FINGERPRINT_SCHEMA,
optional: true,
},
drive: {
schema: DRIVE_NAME_SCHEMA,
optional: true,
},
device: {
schema: LINUX_DRIVE_PATH_SCHEMA,
optional: true,
},
stdin: {
description: "Use standard input as device handle.",
type: bool,
optional: true,
},
},
},
)]
/// Set or clear encryption key
fn set_encryption(
fingerprint: Option<Fingerprint>,
param: Value,
) -> Result<(), Error> {
let result = proxmox::try_block!({
let mut handle = get_tape_handle(&param)?;
handle.set_encryption(fingerprint)?;
Ok(())
}).map_err(|err: Error| err.to_string());
println!("{}", serde_json::to_string_pretty(&result)?);
Ok(())
}
#[api(
input: {
properties: {
@ -260,6 +300,10 @@ fn main() -> Result<(), Error> {
"volume-statistics",
CliCommand::new(&API_METHOD_VOLUME_STATISTICS)
)
.insert(
"encryption",
CliCommand::new(&API_METHOD_SET_ENCRYPTION)
)
;
let mut rpcenv = CliEnvironment::new();

1
src/config.rs
View File

@ -27,6 +27,7 @@ pub mod user;
pub mod verify;
pub mod drive;
pub mod media_pool;
pub mod tape_encryption_keys;
/// Check configuration directory permissions
///

126
src/config/tape_encryption_keys.rs Normal file
View File

@ -0,0 +1,126 @@
use std::collections::HashMap;
use anyhow::{bail, Error};
use serde::{Deserialize, Serialize};
use openssl::sha::sha256;
use proxmox::tools::fs::{
file_read_optional_string,
replace_file,
CreateOptions,
};
use crate::{
backup::{
Fingerprint,
},
};
mod hex_key {
use serde::{self, Deserialize, Serializer, Deserializer};
pub fn serialize<S>(
csum: &[u8; 32],
serializer: S,
) -> Result<S::Ok, S::Error>
where
S: Serializer,
{
let s = proxmox::tools::digest_to_hex(csum);
serializer.serialize_str(&s)
}
pub fn deserialize<'de, D>(
deserializer: D,
) -> Result<[u8; 32], D::Error>
where
D: Deserializer<'de>,
{
let s = String::deserialize(deserializer)?;
proxmox::tools::hex_to_digest(&s).map_err(serde::de::Error::custom)
}
}
/// Store Hardware Encryption keys
#[derive(Deserialize, Serialize)]
pub struct EncryptionKeyInfo {
pub hint: String,
#[serde(with = "hex_key")]
pub key: [u8; 32],
pub fingerprint: Fingerprint,
}
impl EncryptionKeyInfo {
pub fn new(key: &[u8; 32], hint: String) -> Self {
Self {
hint,
key: key.clone(),
fingerprint: Fingerprint::new(sha256(key)),
}
}
}
pub const TAPE_KEYS_FILENAME: &str = "/etc/proxmox-backup/tape-encryption-keys.json";
pub const TAPE_KEYS_LOCKFILE: &str = "/etc/proxmox-backup/.tape-encryption-keys.lck";
pub fn load_keys() -> Result<(HashMap<Fingerprint, EncryptionKeyInfo>, [u8;32]), Error> {
let content = file_read_optional_string(TAPE_KEYS_FILENAME)?;
let content = content.unwrap_or_else(|| String::from("[]"));
let digest = openssl::sha::sha256(content.as_bytes());
let list: Vec<EncryptionKeyInfo> = serde_json::from_str(&content)?;
let mut map = HashMap::new();
for item in list {
let expected_fingerprint = Fingerprint::new(sha256(&item.key));
if item.fingerprint != expected_fingerprint {
bail!(
"inconsistent fingerprint ({} != {})",
item.fingerprint,
expected_fingerprint,
);
}
map.insert(item.fingerprint.clone(), item);
}
Ok((map, digest))
}
pub fn save_keys(map: HashMap<Fingerprint, EncryptionKeyInfo>) -> Result<(), Error> {
let mut list = Vec::new();
for (_fp, item) in map {
list.push(item);
}
let raw = serde_json::to_string_pretty(&list)?;
let mode = nix::sys::stat::Mode::from_bits_truncate(0o0600);
// set the correct owner/group/permissions while saving file
// owner(rw) = root, group(r)= root
let options = CreateOptions::new()
.perm(mode)
.owner(nix::unistd::ROOT)
.group(nix::unistd::Gid::from_raw(0));
replace_file(TAPE_KEYS_FILENAME, raw.as_bytes(), options)?;
Ok(())
}
// shell completion helper
pub fn complete_key_fingerprint(_arg: &str, _param: &HashMap<String, String>) -> Vec<String> {
let data = match load_keys() {
Ok((data, _digest)) => data,
Err(_) => return Vec::new(),
};
data.keys().map(|fp| crate::tools::format::as_fingerprint(fp.bytes())).collect()
}

40
src/tape/drive/linux_tape.rs
View File

@ -9,6 +9,8 @@ use nix::fcntl::{fcntl, FcntlArg, OFlag};
use proxmox::sys::error::SysResult;
use crate::{
config,
backup::Fingerprint,
tools::run_command,
api2::types::{
TapeDensity,
@ -24,6 +26,7 @@ use crate::{
mam_extract_media_usage,
read_tape_alert_flags,
read_volume_statistics,
set_encryption,
drive::{
LinuxTapeDrive,
TapeDriver,
@ -504,6 +507,43 @@ impl TapeDriver for LinuxTapeHandle {
.map_err(|err| format_err!("{}", err))
.map(|bits| TapeAlertFlags::from_bits_truncate(bits))
}
/// Set or clear encryption key
///
/// Note: Only 'root' user may run RAW SG commands, so we need to
/// spawn setuid binary 'sg-tape-cmd'. Also, encryption key file
/// is only readable by root.
fn set_encryption(&mut self, key_fingerprint: Option<Fingerprint>) -> Result<(), Error> {
if nix::unistd::Uid::effective().is_root() {
if let Some(ref key_fingerprint) = key_fingerprint {
let (key_map, _digest) = config::tape_encryption_keys::load_keys()?;
match key_map.get(key_fingerprint) {
Some(item) => {
return set_encryption(&mut self.file, Some(item.key));
}
None => bail!("unknown tape encryption key '{}'", key_fingerprint),
}
} else {
return set_encryption(&mut self.file, None);
}
}
let mut command = std::process::Command::new(
"/usr/lib/x86_64-linux-gnu/proxmox-backup/sg-tape-cmd");
command.args(&["encryption"]);
if let Some(fingerprint) = key_fingerprint {
let fingerprint = crate::tools::format::as_fingerprint(fingerprint.bytes());
command.args(&["--fingerprint", &fingerprint]);
}
command.args(&["--stdin"]);
command.stdin(unsafe { std::process::Stdio::from_raw_fd(self.file.as_raw_fd())});
let output = run_command(command, None)?;
let result: Result<(), String> = serde_json::from_str(&output)?;
result.map_err(|err| format_err!("{}", err))
}
}
/// Write a single EOF mark without flushing buffers

17
src/tape/drive/mod.rs
View File

@ -25,6 +25,7 @@ use proxmox::tools::io::ReadExt;
use proxmox::api::section_config::SectionConfigData;
use crate::{
backup::Fingerprint,
api2::types::{
VirtualTapeDrive,
LinuxTapeDrive,
@ -163,6 +164,14 @@ pub trait TapeDriver {
fn tape_alert_flags(&mut self) -> Result<TapeAlertFlags, Error> {
Ok(TapeAlertFlags::empty())
}
/// Set or clear encryption key
fn set_encryption(&mut self, key_fingerprint: Option<Fingerprint>) -> Result<(), Error> {
if key_fingerprint.is_some() {
bail!("drive does not support encryption");
}
Ok(())
}
}
/// Get the media changer (MediaChange + name) associated with a tape drive.
@ -234,14 +243,12 @@ pub fn open_drive(
match section_type_name.as_ref() {
"virtual" => {
let tape = VirtualTapeDrive::deserialize(config)?;
let handle = tape.open()
.map_err(|err| format_err!("open drive '{}' ({}) failed - {}", drive, tape.path, err))?;
Ok(Box::new(handle))
let handle = tape.open()?;
Ok(Box::new(handle))
}
"linux" => {
let tape = LinuxTapeDrive::deserialize(config)?;
let handle = tape.open()
.map_err(|err| format_err!("open drive '{}' ({}) failed - {}", drive, tape.path, err))?;
let handle = tape.open()?;
Ok(Box::new(handle))
}
_ => bail!("unknown drive type '{}' - internal error"),

22
src/tape/drive/virtual_tape.rs
View File

@ -40,18 +40,20 @@ impl VirtualTapeDrive {
/// This needs to lock the drive
pub fn open(&self) -> Result<VirtualTapeHandle, Error> {
let mut lock_path = std::path::PathBuf::from(&self.path);
lock_path.push(".drive.lck");
proxmox::try_block!({
let mut lock_path = std::path::PathBuf::from(&self.path);
lock_path.push(".drive.lck");
let timeout = std::time::Duration::new(10, 0);
let lock = proxmox::tools::fs::open_file_locked(&lock_path, timeout, true)?;
let timeout = std::time::Duration::new(10, 0);
let lock = proxmox::tools::fs::open_file_locked(&lock_path, timeout, true)?;
Ok(VirtualTapeHandle {
_lock: lock,
drive_name: self.name.clone(),
max_size: self.max_size.unwrap_or(64*1024*1024),
path: std::path::PathBuf::from(&self.path),
})
Ok(VirtualTapeHandle {
_lock: lock,
drive_name: self.name.clone(),
max_size: self.max_size.unwrap_or(64*1024*1024),
path: std::path::PathBuf::from(&self.path),
})
}).map_err(|err: Error| format_err!("open drive '{}' ({}) failed - {}", self.name, self.path, err))
}
}