// Copyright 2020, The Android Open Source Project // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. //! This is the Keystore 2.0 database module. //! The database module provides a connection to the backing SQLite store. //! We have two databases one for persistent key blob storage and one for //! items that have a per boot life cycle. //! //! ## Persistent database //! The persistent database has tables for key blobs. They are organized //! as follows: //! The `keyentry` table is the primary table for key entries. It is //! accompanied by two tables for blobs and parameters. //! Each key entry occupies exactly one row in the `keyentry` table and //! zero or more rows in the tables `blobentry` and `keyparameter`. //! //! ## Per boot database //! The per boot database stores items with a per boot lifecycle. //! Currently, there is only the `grant` table in this database. //! Grants are references to a key that can be used to access a key by //! clients that don't own that key. Grants can only be created by the //! owner of a key. And only certain components can create grants. //! This is governed by SEPolicy. //! //! ## Access control //! Some database functions that load keys or create grants perform //! access control. This is because in some cases access control //! can only be performed after some information about the designated //! key was loaded from the database. To decouple the permission checks //! from the database module these functions take permission check //! callbacks. mod perboot; pub(crate) mod utils; mod versioning; #[cfg(test)] pub mod tests; use crate::gc::Gc; use crate::impl_metadata; // This is in database/utils.rs use crate::key_parameter::{KeyParameter, KeyParameterValue, Tag}; use crate::ks_err; use crate::permission::KeyPermSet; use crate::utils::{get_current_time_in_milliseconds, watchdog as wd, AID_USER_OFFSET}; use crate::{ error::{Error as KsError, ErrorCode, ResponseCode}, super_key::SuperKeyType, }; use android_hardware_security_keymint::aidl::android::hardware::security::keymint::{ HardwareAuthToken::HardwareAuthToken, HardwareAuthenticatorType::HardwareAuthenticatorType, SecurityLevel::SecurityLevel, }; use android_security_metrics::aidl::android::security::metrics::{ Storage::Storage as MetricsStorage, StorageStats::StorageStats, }; use android_system_keystore2::aidl::android::system::keystore2::{ Domain::Domain, KeyDescriptor::KeyDescriptor, }; use anyhow::{anyhow, Context, Result}; use keystore2_flags; use std::{convert::TryFrom, convert::TryInto, ops::Deref, sync::LazyLock, time::SystemTimeError}; use utils as db_utils; use utils::SqlField; use keystore2_crypto::ZVec; use log::error; #[cfg(not(test))] use rand::prelude::random; use rusqlite::{ params, params_from_iter, types::FromSql, types::FromSqlResult, types::ToSqlOutput, types::{FromSqlError, Value, ValueRef}, Connection, OptionalExtension, ToSql, Transaction, }; use std::{ collections::{HashMap, HashSet}, path::Path, sync::{Arc, Condvar, Mutex}, time::{Duration, SystemTime}, }; use TransactionBehavior::Immediate; #[cfg(test)] use tests::random; /// Wrapper for `rusqlite::TransactionBehavior` which includes information about the transaction /// being performed. #[derive(Clone, Copy)] enum TransactionBehavior { Deferred, Immediate(&'static str), } impl From for rusqlite::TransactionBehavior { fn from(val: TransactionBehavior) -> Self { match val { TransactionBehavior::Deferred => rusqlite::TransactionBehavior::Deferred, TransactionBehavior::Immediate(_) => rusqlite::TransactionBehavior::Immediate, } } } impl TransactionBehavior { fn name(&self) -> Option<&'static str> { match self { TransactionBehavior::Deferred => None, TransactionBehavior::Immediate(v) => Some(v), } } } /// Access information for a key. #[derive(Debug)] struct KeyAccessInfo { key_id: i64, descriptor: KeyDescriptor, vector: Option, } /// If the database returns a busy error code, retry after this interval. const DB_BUSY_RETRY_INTERVAL: Duration = Duration::from_micros(500); impl_metadata!( /// A set of metadata for key entries. #[derive(Debug, Default, Eq, PartialEq)] pub struct KeyMetaData; /// A metadata entry for key entries. #[derive(Debug, Eq, PartialEq, Ord, PartialOrd)] pub enum KeyMetaEntry { /// Date of the creation of the key entry. CreationDate(DateTime) with accessor creation_date, /// Expiration date for attestation keys. AttestationExpirationDate(DateTime) with accessor attestation_expiration_date, /// CBOR Blob that represents a COSE_Key and associated metadata needed for remote /// provisioning AttestationMacedPublicKey(Vec) with accessor attestation_maced_public_key, /// Vector representing the raw public key so results from the server can be matched /// to the right entry AttestationRawPubKey(Vec) with accessor attestation_raw_pub_key, /// SEC1 public key for ECDH encryption Sec1PublicKey(Vec) with accessor sec1_public_key, // --- ADD NEW META DATA FIELDS HERE --- // For backwards compatibility add new entries only to // end of this list and above this comment. }; ); impl KeyMetaData { fn load_from_db(key_id: i64, tx: &Transaction) -> Result { let mut stmt = tx .prepare( "SELECT tag, data from persistent.keymetadata WHERE keyentryid = ?;", ) .context(ks_err!("KeyMetaData::load_from_db: prepare statement failed."))?; let mut metadata: HashMap = Default::default(); let mut rows = stmt .query(params![key_id]) .context(ks_err!("KeyMetaData::load_from_db: query failed."))?; db_utils::with_rows_extract_all(&mut rows, |row| { let db_tag: i64 = row.get(0).context("Failed to read tag.")?; metadata.insert( db_tag, KeyMetaEntry::new_from_sql(db_tag, &SqlField::new(1, row)) .context("Failed to read KeyMetaEntry.")?, ); Ok(()) }) .context(ks_err!("KeyMetaData::load_from_db."))?; Ok(Self { data: metadata }) } fn store_in_db(&self, key_id: i64, tx: &Transaction) -> Result<()> { let mut stmt = tx .prepare( "INSERT or REPLACE INTO persistent.keymetadata (keyentryid, tag, data) VALUES (?, ?, ?);", ) .context(ks_err!("KeyMetaData::store_in_db: Failed to prepare statement."))?; let iter = self.data.iter(); for (tag, entry) in iter { stmt.insert(params![key_id, tag, entry,]).with_context(|| { ks_err!("KeyMetaData::store_in_db: Failed to insert {:?}", entry) })?; } Ok(()) } } impl_metadata!( /// A set of metadata for key blobs. #[derive(Debug, Default, Eq, PartialEq)] pub struct BlobMetaData; /// A metadata entry for key blobs. #[derive(Debug, Eq, PartialEq, Ord, PartialOrd)] pub enum BlobMetaEntry { /// If present, indicates that the blob is encrypted with another key or a key derived /// from a password. EncryptedBy(EncryptedBy) with accessor encrypted_by, /// If the blob is password encrypted this field is set to the /// salt used for the key derivation. Salt(Vec) with accessor salt, /// If the blob is encrypted, this field is set to the initialization vector. Iv(Vec) with accessor iv, /// If the blob is encrypted, this field holds the AEAD TAG. AeadTag(Vec) with accessor aead_tag, /// The uuid of the owning KeyMint instance. KmUuid(Uuid) with accessor km_uuid, /// If the key is ECDH encrypted, this is the ephemeral public key PublicKey(Vec) with accessor public_key, /// If the key is encrypted with a MaxBootLevel key, this is the boot level /// of that key MaxBootLevel(i32) with accessor max_boot_level, // --- ADD NEW META DATA FIELDS HERE --- // For backwards compatibility add new entries only to // end of this list and above this comment. }; ); impl BlobMetaData { fn load_from_db(blob_id: i64, tx: &Transaction) -> Result { let mut stmt = tx .prepare( "SELECT tag, data from persistent.blobmetadata WHERE blobentryid = ?;", ) .context(ks_err!("BlobMetaData::load_from_db: prepare statement failed."))?; let mut metadata: HashMap = Default::default(); let mut rows = stmt.query(params![blob_id]).context(ks_err!("query failed."))?; db_utils::with_rows_extract_all(&mut rows, |row| { let db_tag: i64 = row.get(0).context("Failed to read tag.")?; metadata.insert( db_tag, BlobMetaEntry::new_from_sql(db_tag, &SqlField::new(1, row)) .context("Failed to read BlobMetaEntry.")?, ); Ok(()) }) .context(ks_err!("BlobMetaData::load_from_db"))?; Ok(Self { data: metadata }) } fn store_in_db(&self, blob_id: i64, tx: &Transaction) -> Result<()> { let mut stmt = tx .prepare( "INSERT or REPLACE INTO persistent.blobmetadata (blobentryid, tag, data) VALUES (?, ?, ?);", ) .context(ks_err!("BlobMetaData::store_in_db: Failed to prepare statement.",))?; let iter = self.data.iter(); for (tag, entry) in iter { stmt.insert(params![blob_id, tag, entry,]).with_context(|| { ks_err!("BlobMetaData::store_in_db: Failed to insert {:?}", entry) })?; } Ok(()) } } /// Indicates the type of the keyentry. #[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd)] pub enum KeyType { /// This is a client key type. These keys are created or imported through the Keystore 2.0 /// AIDL interface android.system.keystore2. Client, /// This is a super key type. These keys are created by keystore itself and used to encrypt /// other key blobs to provide LSKF binding. Super, } impl ToSql for KeyType { fn to_sql(&self) -> rusqlite::Result { Ok(ToSqlOutput::Owned(Value::Integer(match self { KeyType::Client => 0, KeyType::Super => 1, }))) } } impl FromSql for KeyType { fn column_result(value: ValueRef) -> FromSqlResult { match i64::column_result(value)? { 0 => Ok(KeyType::Client), 1 => Ok(KeyType::Super), v => Err(FromSqlError::OutOfRange(v)), } } } /// Uuid representation that can be stored in the database. /// Right now it can only be initialized from SecurityLevel. /// Once KeyMint provides a UUID type a corresponding From impl shall be added. #[derive(Debug, Clone, Copy, Default, PartialEq, Eq, PartialOrd, Ord, Hash)] pub struct Uuid([u8; 16]); impl Deref for Uuid { type Target = [u8; 16]; fn deref(&self) -> &Self::Target { &self.0 } } impl From for Uuid { fn from(sec_level: SecurityLevel) -> Self { Self((sec_level.0 as u128).to_be_bytes()) } } impl ToSql for Uuid { fn to_sql(&self) -> rusqlite::Result { self.0.to_sql() } } impl FromSql for Uuid { fn column_result(value: ValueRef<'_>) -> FromSqlResult { let blob = Vec::::column_result(value)?; if blob.len() != 16 { return Err(FromSqlError::OutOfRange(blob.len() as i64)); } let mut arr = [0u8; 16]; arr.copy_from_slice(&blob); Ok(Self(arr)) } } /// Key entries that are not associated with any KeyMint instance, such as pure certificate /// entries are associated with this UUID. pub static KEYSTORE_UUID: Uuid = Uuid([ 0x41, 0xe3, 0xb9, 0xce, 0x27, 0x58, 0x4e, 0x91, 0xbc, 0xfd, 0xa5, 0x5d, 0x91, 0x85, 0xab, 0x11, ]); /// Indicates how the sensitive part of this key blob is encrypted. #[derive(Debug, Eq, PartialEq, Ord, PartialOrd)] pub enum EncryptedBy { /// The keyblob is encrypted by a user password. /// In the database this variant is represented as NULL. Password, /// The keyblob is encrypted by another key with wrapped key id. /// In the database this variant is represented as non NULL value /// that is convertible to i64, typically NUMERIC. KeyId(i64), } impl ToSql for EncryptedBy { fn to_sql(&self) -> rusqlite::Result { match self { Self::Password => Ok(ToSqlOutput::Owned(Value::Null)), Self::KeyId(id) => id.to_sql(), } } } impl FromSql for EncryptedBy { fn column_result(value: ValueRef) -> FromSqlResult { match value { ValueRef::Null => Ok(Self::Password), _ => Ok(Self::KeyId(i64::column_result(value)?)), } } } /// A database representation of wall clock time. DateTime stores unix epoch time as /// i64 in milliseconds. #[derive(Debug, Copy, Clone, Default, Eq, PartialEq, Ord, PartialOrd)] pub struct DateTime(i64); /// Error type returned when creating DateTime or converting it from and to /// SystemTime. #[derive(thiserror::Error, Debug)] pub enum DateTimeError { /// This is returned when SystemTime and Duration computations fail. #[error(transparent)] SystemTimeError(#[from] SystemTimeError), /// This is returned when type conversions fail. #[error(transparent)] TypeConversion(#[from] std::num::TryFromIntError), /// This is returned when checked time arithmetic failed. #[error("Time arithmetic failed.")] TimeArithmetic, } impl DateTime { /// Constructs a new DateTime object denoting the current time. This may fail during /// conversion to unix epoch time and during conversion to the internal i64 representation. pub fn now() -> Result { Ok(Self(SystemTime::now().duration_since(SystemTime::UNIX_EPOCH)?.as_millis().try_into()?)) } /// Constructs a new DateTime object from milliseconds. pub fn from_millis_epoch(millis: i64) -> Self { Self(millis) } /// Returns unix epoch time in milliseconds. pub fn to_millis_epoch(self) -> i64 { self.0 } } impl ToSql for DateTime { fn to_sql(&self) -> rusqlite::Result { Ok(ToSqlOutput::Owned(Value::Integer(self.0))) } } impl FromSql for DateTime { fn column_result(value: ValueRef) -> FromSqlResult { Ok(Self(i64::column_result(value)?)) } } impl TryInto for DateTime { type Error = DateTimeError; fn try_into(self) -> Result { // We want to construct a SystemTime representation equivalent to self, denoting // a point in time THEN, but we cannot set the time directly. We can only construct // a SystemTime denoting NOW, and we can get the duration between EPOCH and NOW, // and between EPOCH and THEN. With this common reference we can construct the // duration between NOW and THEN which we can add to our SystemTime representation // of NOW to get a SystemTime representation of THEN. // Durations can only be positive, thus the if statement below. let now = SystemTime::now(); let now_epoch = now.duration_since(SystemTime::UNIX_EPOCH)?; let then_epoch = Duration::from_millis(self.0.try_into()?); Ok(if now_epoch > then_epoch { // then = now - (now_epoch - then_epoch) now_epoch .checked_sub(then_epoch) .and_then(|d| now.checked_sub(d)) .ok_or(DateTimeError::TimeArithmetic)? } else { // then = now + (then_epoch - now_epoch) then_epoch .checked_sub(now_epoch) .and_then(|d| now.checked_add(d)) .ok_or(DateTimeError::TimeArithmetic)? }) } } impl TryFrom for DateTime { type Error = DateTimeError; fn try_from(t: SystemTime) -> Result { Ok(Self(t.duration_since(SystemTime::UNIX_EPOCH)?.as_millis().try_into()?)) } } #[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Copy, Clone)] enum KeyLifeCycle { /// Existing keys have a key ID but are not fully populated yet. /// This is a transient state. If Keystore finds any such keys when it starts up, it must move /// them to Unreferenced for garbage collection. Existing, /// A live key is fully populated and usable by clients. Live, /// An unreferenced key is scheduled for garbage collection. Unreferenced, } impl ToSql for KeyLifeCycle { fn to_sql(&self) -> rusqlite::Result { match self { Self::Existing => Ok(ToSqlOutput::Owned(Value::Integer(0))), Self::Live => Ok(ToSqlOutput::Owned(Value::Integer(1))), Self::Unreferenced => Ok(ToSqlOutput::Owned(Value::Integer(2))), } } } impl FromSql for KeyLifeCycle { fn column_result(value: ValueRef) -> FromSqlResult { match i64::column_result(value)? { 0 => Ok(KeyLifeCycle::Existing), 1 => Ok(KeyLifeCycle::Live), 2 => Ok(KeyLifeCycle::Unreferenced), v => Err(FromSqlError::OutOfRange(v)), } } } /// Current state of a `blobentry` row. #[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Copy, Clone, Default)] enum BlobState { #[default] /// Current blobentry (of its `subcomponent_type`) for the associated key. Current, /// Blobentry that is no longer the current blob (of its `subcomponent_type`) for the associated /// key. Superseded, /// Blobentry for a key that no longer exists. Orphaned, } impl ToSql for BlobState { fn to_sql(&self) -> rusqlite::Result { match self { Self::Current => Ok(ToSqlOutput::Owned(Value::Integer(0))), Self::Superseded => Ok(ToSqlOutput::Owned(Value::Integer(1))), Self::Orphaned => Ok(ToSqlOutput::Owned(Value::Integer(2))), } } } impl FromSql for BlobState { fn column_result(value: ValueRef) -> FromSqlResult { match i64::column_result(value)? { 0 => Ok(Self::Current), 1 => Ok(Self::Superseded), 2 => Ok(Self::Orphaned), v => Err(FromSqlError::OutOfRange(v)), } } } /// Keys have a KeyMint blob component and optional public certificate and /// certificate chain components. /// KeyEntryLoadBits is a bitmap that indicates to `KeystoreDB::load_key_entry` /// which components shall be loaded from the database if present. #[derive(Debug, Clone, Copy, Eq, PartialEq, Ord, PartialOrd)] pub struct KeyEntryLoadBits(u32); impl KeyEntryLoadBits { /// Indicate to `KeystoreDB::load_key_entry` that no component shall be loaded. pub const NONE: KeyEntryLoadBits = Self(0); /// Indicate to `KeystoreDB::load_key_entry` that the KeyMint component shall be loaded. pub const KM: KeyEntryLoadBits = Self(1); /// Indicate to `KeystoreDB::load_key_entry` that the Public components shall be loaded. pub const PUBLIC: KeyEntryLoadBits = Self(2); /// Indicate to `KeystoreDB::load_key_entry` that both components shall be loaded. pub const BOTH: KeyEntryLoadBits = Self(3); /// Returns true if this object indicates that the public components shall be loaded. pub const fn load_public(&self) -> bool { self.0 & Self::PUBLIC.0 != 0 } /// Returns true if the object indicates that the KeyMint component shall be loaded. pub const fn load_km(&self) -> bool { self.0 & Self::KM.0 != 0 } } static KEY_ID_LOCK: LazyLock = LazyLock::new(KeyIdLockDb::new); struct KeyIdLockDb { locked_keys: Mutex>, cond_var: Condvar, } /// A locked key. While a guard exists for a given key id, the same key cannot be loaded /// from the database a second time. Most functions manipulating the key blob database /// require a KeyIdGuard. #[derive(Debug)] pub struct KeyIdGuard(i64); impl KeyIdLockDb { fn new() -> Self { Self { locked_keys: Mutex::new(HashSet::new()), cond_var: Condvar::new() } } /// This function blocks until an exclusive lock for the given key entry id can /// be acquired. It returns a guard object, that represents the lifecycle of the /// acquired lock. fn get(&self, key_id: i64) -> KeyIdGuard { let mut locked_keys = self.locked_keys.lock().unwrap(); while locked_keys.contains(&key_id) { locked_keys = self.cond_var.wait(locked_keys).unwrap(); } locked_keys.insert(key_id); KeyIdGuard(key_id) } /// This function attempts to acquire an exclusive lock on a given key id. If the /// given key id is already taken the function returns None immediately. If a lock /// can be acquired this function returns a guard object, that represents the /// lifecycle of the acquired lock. fn try_get(&self, key_id: i64) -> Option { let mut locked_keys = self.locked_keys.lock().unwrap(); if locked_keys.insert(key_id) { Some(KeyIdGuard(key_id)) } else { None } } } impl KeyIdGuard { /// Get the numeric key id of the locked key. pub fn id(&self) -> i64 { self.0 } } impl Drop for KeyIdGuard { fn drop(&mut self) { let mut locked_keys = KEY_ID_LOCK.locked_keys.lock().unwrap(); locked_keys.remove(&self.0); drop(locked_keys); KEY_ID_LOCK.cond_var.notify_all(); } } /// This type represents a certificate and certificate chain entry for a key. #[derive(Debug, Default)] pub struct CertificateInfo { cert: Option>, cert_chain: Option>, } /// This type represents a Blob with its metadata and an optional superseded blob. #[derive(Debug)] pub struct BlobInfo<'a> { blob: &'a [u8], metadata: &'a BlobMetaData, /// Superseded blobs are an artifact of legacy import. In some rare occasions /// the key blob needs to be upgraded during import. In that case two /// blob are imported, the superseded one will have to be imported first, /// so that the garbage collector can reap it. superseded_blob: Option<(&'a [u8], &'a BlobMetaData)>, } impl<'a> BlobInfo<'a> { /// Create a new instance of blob info with blob and corresponding metadata /// and no superseded blob info. pub fn new(blob: &'a [u8], metadata: &'a BlobMetaData) -> Self { Self { blob, metadata, superseded_blob: None } } /// Create a new instance of blob info with blob and corresponding metadata /// as well as superseded blob info. pub fn new_with_superseded( blob: &'a [u8], metadata: &'a BlobMetaData, superseded_blob: Option<(&'a [u8], &'a BlobMetaData)>, ) -> Self { Self { blob, metadata, superseded_blob } } } impl CertificateInfo { /// Constructs a new CertificateInfo object from `cert` and `cert_chain` pub fn new(cert: Option>, cert_chain: Option>) -> Self { Self { cert, cert_chain } } /// Take the cert pub fn take_cert(&mut self) -> Option> { self.cert.take() } /// Take the cert chain pub fn take_cert_chain(&mut self) -> Option> { self.cert_chain.take() } } /// This type represents a certificate chain with a private key corresponding to the leaf /// certificate. TODO(jbires): This will be used in a follow-on CL, for now it's used in the tests. pub struct CertificateChain { /// A KM key blob pub private_key: ZVec, /// A batch cert for private_key pub batch_cert: Vec, /// A full certificate chain from root signing authority to private_key, including batch_cert /// for convenience. pub cert_chain: Vec, } /// This type represents a Keystore 2.0 key entry. /// An entry has a unique `id` by which it can be found in the database. /// It has a security level field, key parameters, and three optional fields /// for the KeyMint blob, public certificate and a public certificate chain. #[derive(Debug, Default, Eq, PartialEq)] pub struct KeyEntry { id: i64, key_blob_info: Option<(Vec, BlobMetaData)>, cert: Option>, cert_chain: Option>, km_uuid: Uuid, parameters: Vec, metadata: KeyMetaData, pure_cert: bool, } impl KeyEntry { /// Returns the unique id of the Key entry. pub fn id(&self) -> i64 { self.id } /// Exposes the optional KeyMint blob. pub fn key_blob_info(&self) -> &Option<(Vec, BlobMetaData)> { &self.key_blob_info } /// Extracts the Optional KeyMint blob including its metadata. pub fn take_key_blob_info(&mut self) -> Option<(Vec, BlobMetaData)> { self.key_blob_info.take() } /// Exposes the optional public certificate. pub fn cert(&self) -> &Option> { &self.cert } /// Extracts the optional public certificate. pub fn take_cert(&mut self) -> Option> { self.cert.take() } /// Extracts the optional public certificate_chain. pub fn take_cert_chain(&mut self) -> Option> { self.cert_chain.take() } /// Returns the uuid of the owning KeyMint instance. pub fn km_uuid(&self) -> &Uuid { &self.km_uuid } /// Consumes this key entry and extracts the keyparameters from it. pub fn into_key_parameters(self) -> Vec { self.parameters } /// Exposes the key metadata of this key entry. pub fn metadata(&self) -> &KeyMetaData { &self.metadata } /// This returns true if the entry is a pure certificate entry with no /// private key component. pub fn pure_cert(&self) -> bool { self.pure_cert } } /// Indicates the sub component of a key entry for persistent storage. #[derive(Debug, Clone, Copy, Eq, PartialEq, Ord, PartialOrd)] pub struct SubComponentType(u32); impl SubComponentType { /// Persistent identifier for a key blob. pub const KEY_BLOB: SubComponentType = Self(0); /// Persistent identifier for a certificate blob. pub const CERT: SubComponentType = Self(1); /// Persistent identifier for a certificate chain blob. pub const CERT_CHAIN: SubComponentType = Self(2); } impl ToSql for SubComponentType { fn to_sql(&self) -> rusqlite::Result { self.0.to_sql() } } impl FromSql for SubComponentType { fn column_result(value: ValueRef) -> FromSqlResult { Ok(Self(u32::column_result(value)?)) } } /// This trait is private to the database module. It is used to convey whether or not the garbage /// collector shall be invoked after a database access. All closures passed to /// `KeystoreDB::with_transaction` return a tuple (bool, T) where the bool indicates if the /// gc needs to be triggered. This convenience function allows to turn any anyhow::Result /// into anyhow::Result<(bool, T)> by simply appending one of `.do_gc(bool)`, `.no_gc()`, or /// `.need_gc()`. trait DoGc { fn do_gc(self, need_gc: bool) -> Result<(bool, T)>; fn no_gc(self) -> Result<(bool, T)>; fn need_gc(self) -> Result<(bool, T)>; } impl DoGc for Result { fn do_gc(self, need_gc: bool) -> Result<(bool, T)> { self.map(|r| (need_gc, r)) } fn no_gc(self) -> Result<(bool, T)> { self.do_gc(false) } fn need_gc(self) -> Result<(bool, T)> { self.do_gc(true) } } /// KeystoreDB wraps a connection to an SQLite database and tracks its /// ownership. It also implements all of Keystore 2.0's database functionality. pub struct KeystoreDB { conn: Connection, gc: Option>, perboot: Arc, } /// Database representation of the monotonic time retrieved from the system call clock_gettime with /// CLOCK_BOOTTIME. Stores monotonic time as i64 in milliseconds. #[derive(Debug, Copy, Clone, Default, Eq, PartialEq, Ord, PartialOrd)] pub struct BootTime(i64); impl BootTime { /// Constructs a new BootTime pub fn now() -> Self { Self(get_current_time_in_milliseconds()) } /// Returns the value of BootTime in milliseconds as i64 pub fn milliseconds(&self) -> i64 { self.0 } /// Returns the integer value of BootTime as i64 pub fn seconds(&self) -> i64 { self.0 / 1000 } /// Like i64::checked_sub. pub fn checked_sub(&self, other: &Self) -> Option { self.0.checked_sub(other.0).map(Self) } } impl ToSql for BootTime { fn to_sql(&self) -> rusqlite::Result { Ok(ToSqlOutput::Owned(Value::Integer(self.0))) } } impl FromSql for BootTime { fn column_result(value: ValueRef) -> FromSqlResult { Ok(Self(i64::column_result(value)?)) } } /// This struct encapsulates the information to be stored in the database about the auth tokens /// received by keystore. #[derive(Clone)] pub struct AuthTokenEntry { auth_token: HardwareAuthToken, // Time received in milliseconds time_received: BootTime, } impl AuthTokenEntry { fn new(auth_token: HardwareAuthToken, time_received: BootTime) -> Self { AuthTokenEntry { auth_token, time_received } } /// Checks if this auth token satisfies the given authentication information. pub fn satisfies(&self, user_secure_ids: &[i64], auth_type: HardwareAuthenticatorType) -> bool { user_secure_ids.iter().any(|&sid| { (sid == self.auth_token.userId || sid == self.auth_token.authenticatorId) && ((auth_type.0 & self.auth_token.authenticatorType.0) != 0) }) } /// Returns the auth token wrapped by the AuthTokenEntry pub fn auth_token(&self) -> &HardwareAuthToken { &self.auth_token } /// Returns the auth token wrapped by the AuthTokenEntry pub fn take_auth_token(self) -> HardwareAuthToken { self.auth_token } /// Returns the time that this auth token was received. pub fn time_received(&self) -> BootTime { self.time_received } /// Returns the challenge value of the auth token. pub fn challenge(&self) -> i64 { self.auth_token.challenge } } /// Information about a superseded blob (a blob that is no longer the /// most recent blob of that type for a given key, due to upgrade or /// replacement). pub struct SupersededBlob { /// ID pub blob_id: i64, /// Contents. pub blob: Vec, /// Metadata. pub metadata: BlobMetaData, } impl KeystoreDB { const UNASSIGNED_KEY_ID: i64 = -1i64; const CURRENT_DB_VERSION: u32 = 2; const UPGRADERS: &'static [fn(&Transaction) -> Result] = &[Self::from_0_to_1, Self::from_1_to_2]; /// Name of the file that holds the cross-boot persistent database. pub const PERSISTENT_DB_FILENAME: &'static str = "persistent.sqlite"; /// This will create a new database connection connecting the two /// files persistent.sqlite and perboot.sqlite in the given directory. /// It also attempts to initialize all of the tables. /// KeystoreDB cannot be used by multiple threads. /// Each thread should open their own connection using `thread_local!`. pub fn new(db_root: &Path, gc: Option>) -> Result { let _wp = wd::watch("KeystoreDB::new"); let persistent_path = Self::make_persistent_path(db_root)?; let conn = Self::make_connection(&persistent_path)?; let mut db = Self { conn, gc, perboot: perboot::PERBOOT_DB.clone() }; db.with_transaction(Immediate("TX_new"), |tx| { versioning::upgrade_database(tx, Self::CURRENT_DB_VERSION, Self::UPGRADERS) .context(ks_err!("KeystoreDB::new: trying to upgrade database."))?; Self::init_tables(tx).context("Trying to initialize tables.").no_gc() })?; Ok(db) } // This upgrade function deletes all MAX_BOOT_LEVEL keys, that were generated before // cryptographic binding to the boot level keys was implemented. fn from_0_to_1(tx: &Transaction) -> Result { tx.execute( "UPDATE persistent.keyentry SET state = ? WHERE id IN (SELECT keyentryid FROM persistent.keyparameter WHERE tag = ?) AND id NOT IN ( SELECT keyentryid FROM persistent.blobentry WHERE id IN ( SELECT blobentryid FROM persistent.blobmetadata WHERE tag = ? ) );", params![KeyLifeCycle::Unreferenced, Tag::MAX_BOOT_LEVEL.0, BlobMetaData::MaxBootLevel], ) .context(ks_err!("Failed to delete logical boot level keys."))?; // DB version is now 1. Ok(1) } // This upgrade function adds an additional `state INTEGER` column to the blobentry // table, and populates it based on whether each blob is the most recent of its type for // the corresponding key. fn from_1_to_2(tx: &Transaction) -> Result { tx.execute( "ALTER TABLE persistent.blobentry ADD COLUMN state INTEGER DEFAULT 0;", params![], ) .context(ks_err!("Failed to add state column"))?; // Mark keyblobs that are not the most recent for their corresponding key. // This may take a while if there are excessive numbers of keys in the database. let _wp = wd::watch("KeystoreDB::from_1_to_2 mark all non-current keyblobs"); let sc_key_blob = SubComponentType::KEY_BLOB; let mut stmt = tx .prepare( "UPDATE persistent.blobentry SET state=? WHERE subcomponent_type = ? AND id NOT IN ( SELECT MAX(id) FROM persistent.blobentry WHERE subcomponent_type = ? GROUP BY keyentryid, subcomponent_type );", ) .context("Trying to prepare query to mark superseded keyblobs")?; stmt.execute(params![BlobState::Superseded, sc_key_blob, sc_key_blob]) .context(ks_err!("Failed to set state=superseded state for keyblobs"))?; log::info!("marked non-current blobentry rows for keyblobs as superseded"); // Mark keyblobs that don't have a corresponding key. // This may take a while if there are excessive numbers of keys in the database. let _wp = wd::watch("KeystoreDB::from_1_to_2 mark all orphaned keyblobs"); let mut stmt = tx .prepare( "UPDATE persistent.blobentry SET state=? WHERE subcomponent_type = ? AND NOT EXISTS (SELECT id FROM persistent.keyentry WHERE id = keyentryid);", ) .context("Trying to prepare query to mark orphaned keyblobs")?; stmt.execute(params![BlobState::Orphaned, sc_key_blob]) .context(ks_err!("Failed to set state=orphaned for keyblobs"))?; log::info!("marked orphaned blobentry rows for keyblobs"); // Add an index to make it fast to find out of date blobentry rows. let _wp = wd::watch("KeystoreDB::from_1_to_2 add blobentry index"); tx.execute( "CREATE INDEX IF NOT EXISTS persistent.blobentry_state_index ON blobentry(subcomponent_type, state);", [], ) .context("Failed to create index blobentry_state_index.")?; // Add an index to make it fast to find unreferenced keyentry rows. let _wp = wd::watch("KeystoreDB::from_1_to_2 add keyentry state index"); tx.execute( "CREATE INDEX IF NOT EXISTS persistent.keyentry_state_index ON keyentry(state);", [], ) .context("Failed to create index keyentry_state_index.")?; // DB version is now 2. Ok(2) } fn init_tables(tx: &Transaction) -> Result<()> { tx.execute( "CREATE TABLE IF NOT EXISTS persistent.keyentry ( id INTEGER UNIQUE, key_type INTEGER, domain INTEGER, namespace INTEGER, alias BLOB, state INTEGER, km_uuid BLOB);", [], ) .context("Failed to initialize \"keyentry\" table.")?; tx.execute( "CREATE INDEX IF NOT EXISTS persistent.keyentry_id_index ON keyentry(id);", [], ) .context("Failed to create index keyentry_id_index.")?; tx.execute( "CREATE INDEX IF NOT EXISTS persistent.keyentry_domain_namespace_index ON keyentry(domain, namespace, alias);", [], ) .context("Failed to create index keyentry_domain_namespace_index.")?; // Index added in v2 of database schema. tx.execute( "CREATE INDEX IF NOT EXISTS persistent.keyentry_state_index ON keyentry(state);", [], ) .context("Failed to create index keyentry_state_index.")?; tx.execute( "CREATE TABLE IF NOT EXISTS persistent.blobentry ( id INTEGER PRIMARY KEY, subcomponent_type INTEGER, keyentryid INTEGER, blob BLOB, state INTEGER DEFAULT 0);", // `state` added in v2 of schema [], ) .context("Failed to initialize \"blobentry\" table.")?; tx.execute( "CREATE INDEX IF NOT EXISTS persistent.blobentry_keyentryid_index ON blobentry(keyentryid);", [], ) .context("Failed to create index blobentry_keyentryid_index.")?; // Index added in v2 of database schema. tx.execute( "CREATE INDEX IF NOT EXISTS persistent.blobentry_state_index ON blobentry(subcomponent_type, state);", [], ) .context("Failed to create index blobentry_state_index.")?; tx.execute( "CREATE TABLE IF NOT EXISTS persistent.blobmetadata ( id INTEGER PRIMARY KEY, blobentryid INTEGER, tag INTEGER, data ANY, UNIQUE (blobentryid, tag));", [], ) .context("Failed to initialize \"blobmetadata\" table.")?; tx.execute( "CREATE INDEX IF NOT EXISTS persistent.blobmetadata_blobentryid_index ON blobmetadata(blobentryid);", [], ) .context("Failed to create index blobmetadata_blobentryid_index.")?; tx.execute( "CREATE TABLE IF NOT EXISTS persistent.keyparameter ( keyentryid INTEGER, tag INTEGER, data ANY, security_level INTEGER);", [], ) .context("Failed to initialize \"keyparameter\" table.")?; tx.execute( "CREATE INDEX IF NOT EXISTS persistent.keyparameter_keyentryid_index ON keyparameter(keyentryid);", [], ) .context("Failed to create index keyparameter_keyentryid_index.")?; tx.execute( "CREATE TABLE IF NOT EXISTS persistent.keymetadata ( keyentryid INTEGER, tag INTEGER, data ANY, UNIQUE (keyentryid, tag));", [], ) .context("Failed to initialize \"keymetadata\" table.")?; tx.execute( "CREATE INDEX IF NOT EXISTS persistent.keymetadata_keyentryid_index ON keymetadata(keyentryid);", [], ) .context("Failed to create index keymetadata_keyentryid_index.")?; tx.execute( "CREATE TABLE IF NOT EXISTS persistent.grant ( id INTEGER UNIQUE, grantee INTEGER, keyentryid INTEGER, access_vector INTEGER);", [], ) .context("Failed to initialize \"grant\" table.")?; Ok(()) } fn make_persistent_path(db_root: &Path) -> Result { // Build the path to the sqlite file. let mut persistent_path = db_root.to_path_buf(); persistent_path.push(Self::PERSISTENT_DB_FILENAME); // Now convert them to strings prefixed with "file:" let mut persistent_path_str = "file:".to_owned(); persistent_path_str.push_str(&persistent_path.to_string_lossy()); // Connect to database in specific mode let persistent_path_mode = if keystore2_flags::wal_db_journalmode_v3() { "?journal_mode=WAL".to_owned() } else { "?journal_mode=DELETE".to_owned() }; persistent_path_str.push_str(&persistent_path_mode); Ok(persistent_path_str) } fn make_connection(persistent_file: &str) -> Result { let conn = Connection::open_in_memory().context("Failed to initialize SQLite connection.")?; loop { if let Err(e) = conn .execute("ATTACH DATABASE ? as persistent;", params![persistent_file]) .context("Failed to attach database persistent.") { if Self::is_locked_error(&e) { std::thread::sleep(DB_BUSY_RETRY_INTERVAL); continue; } else { return Err(e); } } break; } // Drop the cache size from default (2M) to 0.5M conn.execute("PRAGMA persistent.cache_size = -500;", params![]) .context("Failed to decrease cache size for persistent db")?; Ok(conn) } fn do_table_size_query( &mut self, storage_type: MetricsStorage, query: &str, params: &[&str], ) -> Result { let (total, unused) = self.with_transaction(TransactionBehavior::Deferred, |tx| { tx.query_row(query, params_from_iter(params), |row| Ok((row.get(0)?, row.get(1)?))) .with_context(|| { ks_err!("get_storage_stat: Error size of storage type {}", storage_type.0) }) .no_gc() })?; Ok(StorageStats { storage_type, size: total, unused_size: unused }) } fn get_total_size(&mut self) -> Result { self.do_table_size_query( MetricsStorage::DATABASE, "SELECT page_count * page_size, freelist_count * page_size FROM pragma_page_count('persistent'), pragma_page_size('persistent'), persistent.pragma_freelist_count();", &[], ) } fn get_table_size( &mut self, storage_type: MetricsStorage, schema: &str, table: &str, ) -> Result { self.do_table_size_query( storage_type, "SELECT pgsize,unused FROM dbstat(?1) WHERE name=?2 AND aggregate=TRUE;", &[schema, table], ) } /// Fetches a storage statistics atom for a given storage type. For storage /// types that map to a table, information about the table's storage is /// returned. Requests for storage types that are not DB tables return None. pub fn get_storage_stat(&mut self, storage_type: MetricsStorage) -> Result { let _wp = wd::watch_millis_with("KeystoreDB::get_storage_stat", 500, storage_type); match storage_type { MetricsStorage::DATABASE => self.get_total_size(), MetricsStorage::KEY_ENTRY => { self.get_table_size(storage_type, "persistent", "keyentry") } MetricsStorage::KEY_ENTRY_ID_INDEX => { self.get_table_size(storage_type, "persistent", "keyentry_id_index") } MetricsStorage::KEY_ENTRY_DOMAIN_NAMESPACE_INDEX => { self.get_table_size(storage_type, "persistent", "keyentry_domain_namespace_index") } MetricsStorage::BLOB_ENTRY => { self.get_table_size(storage_type, "persistent", "blobentry") } MetricsStorage::BLOB_ENTRY_KEY_ENTRY_ID_INDEX => { self.get_table_size(storage_type, "persistent", "blobentry_keyentryid_index") } MetricsStorage::KEY_PARAMETER => { self.get_table_size(storage_type, "persistent", "keyparameter") } MetricsStorage::KEY_PARAMETER_KEY_ENTRY_ID_INDEX => { self.get_table_size(storage_type, "persistent", "keyparameter_keyentryid_index") } MetricsStorage::KEY_METADATA => { self.get_table_size(storage_type, "persistent", "keymetadata") } MetricsStorage::KEY_METADATA_KEY_ENTRY_ID_INDEX => { self.get_table_size(storage_type, "persistent", "keymetadata_keyentryid_index") } MetricsStorage::GRANT => self.get_table_size(storage_type, "persistent", "grant"), MetricsStorage::AUTH_TOKEN => { // Since the table is actually a BTreeMap now, unused_size is not meaningfully // reportable // Size provided is only an approximation Ok(StorageStats { storage_type, size: (self.perboot.auth_tokens_len() * std::mem::size_of::()) as i32, unused_size: 0, }) } MetricsStorage::BLOB_METADATA => { self.get_table_size(storage_type, "persistent", "blobmetadata") } MetricsStorage::BLOB_METADATA_BLOB_ENTRY_ID_INDEX => { self.get_table_size(storage_type, "persistent", "blobmetadata_blobentryid_index") } _ => Err(anyhow::Error::msg(format!("Unsupported storage type: {}", storage_type.0))), } } /// This function is intended to be used by the garbage collector. /// It deletes the blobs given by `blob_ids_to_delete`. It then tries to find up to `max_blobs` /// superseded key blobs that might need special handling by the garbage collector. /// If no further superseded blobs can be found it deletes all other superseded blobs that don't /// need special handling and returns None. pub fn handle_next_superseded_blobs( &mut self, blob_ids_to_delete: &[i64], max_blobs: usize, ) -> Result> { let _wp = wd::watch("KeystoreDB::handle_next_superseded_blob"); self.with_transaction(Immediate("TX_handle_next_superseded_blob"), |tx| { // Delete the given blobs. for blob_id in blob_ids_to_delete { tx.execute( "DELETE FROM persistent.blobmetadata WHERE blobentryid = ?;", params![blob_id], ) .context(ks_err!("Trying to delete blob metadata: {:?}", blob_id))?; tx.execute("DELETE FROM persistent.blobentry WHERE id = ?;", params![blob_id]) .context(ks_err!("Trying to delete blob: {:?}", blob_id))?; } Self::cleanup_unreferenced(tx).context("Trying to cleanup unreferenced.")?; // Find up to `max_blobs` more out-of-date key blobs, load their metadata and return it. let result: Vec<(i64, Vec)> = if keystore2_flags::use_blob_state_column() { let _wp = wd::watch("KeystoreDB::handle_next_superseded_blob find_next v2"); let mut stmt = tx .prepare( "SELECT id, blob FROM persistent.blobentry WHERE subcomponent_type = ? AND state != ? LIMIT ?;", ) .context("Trying to prepare query for superseded blobs.")?; let rows = stmt .query_map( params![SubComponentType::KEY_BLOB, BlobState::Current, max_blobs as i64], |row| Ok((row.get(0)?, row.get(1)?)), ) .context("Trying to query superseded blob.")?; rows.collect::)>, rusqlite::Error>>() .context("Trying to extract superseded blobs.")? } else { let _wp = wd::watch("KeystoreDB::handle_next_superseded_blob find_next v1"); let mut stmt = tx .prepare( "SELECT id, blob FROM persistent.blobentry WHERE subcomponent_type = ? AND ( id NOT IN ( SELECT MAX(id) FROM persistent.blobentry WHERE subcomponent_type = ? GROUP BY keyentryid, subcomponent_type ) OR keyentryid NOT IN (SELECT id FROM persistent.keyentry) ) LIMIT ?;", ) .context("Trying to prepare query for superseded blobs.")?; let rows = stmt .query_map( params![ SubComponentType::KEY_BLOB, SubComponentType::KEY_BLOB, max_blobs as i64, ], |row| Ok((row.get(0)?, row.get(1)?)), ) .context("Trying to query superseded blob.")?; rows.collect::)>, rusqlite::Error>>() .context("Trying to extract superseded blobs.")? }; let _wp = wd::watch("KeystoreDB::handle_next_superseded_blob load_metadata"); let result = result .into_iter() .map(|(blob_id, blob)| { Ok(SupersededBlob { blob_id, blob, metadata: BlobMetaData::load_from_db(blob_id, tx)?, }) }) .collect::>>() .context("Trying to load blob metadata.")?; if !result.is_empty() { return Ok(result).no_gc(); } // We did not find any out-of-date key blobs, so let's remove other types of superseded // blob in one transaction. if keystore2_flags::use_blob_state_column() { let _wp = wd::watch("KeystoreDB::handle_next_superseded_blob delete v2"); tx.execute( "DELETE FROM persistent.blobentry WHERE subcomponent_type != ? AND state != ?;", params![SubComponentType::KEY_BLOB, BlobState::Current], ) .context("Trying to purge out-of-date blobs (other than keyblobs)")?; } else { let _wp = wd::watch("KeystoreDB::handle_next_superseded_blob delete v1"); tx.execute( "DELETE FROM persistent.blobentry WHERE NOT subcomponent_type = ? AND ( id NOT IN ( SELECT MAX(id) FROM persistent.blobentry WHERE NOT subcomponent_type = ? GROUP BY keyentryid, subcomponent_type ) OR keyentryid NOT IN (SELECT id FROM persistent.keyentry) );", params![SubComponentType::KEY_BLOB, SubComponentType::KEY_BLOB], ) .context("Trying to purge superseded blobs.")?; } Ok(vec![]).no_gc() }) .context(ks_err!()) } /// This maintenance function should be called only once before the database is used for the /// first time. It restores the invariant that `KeyLifeCycle::Existing` is a transient state. /// The function transitions all key entries from Existing to Unreferenced unconditionally and /// returns the number of rows affected. If this returns a value greater than 0, it means that /// Keystore crashed at some point during key generation. Callers may want to log such /// occurrences. /// Unlike with `mark_unreferenced`, we don't need to purge grants, because only keys that made /// it to `KeyLifeCycle::Live` may have grants. pub fn cleanup_leftovers(&mut self) -> Result { let _wp = wd::watch("KeystoreDB::cleanup_leftovers"); self.with_transaction(Immediate("TX_cleanup_leftovers"), |tx| { tx.execute( "UPDATE persistent.keyentry SET state = ? WHERE state = ?;", params![KeyLifeCycle::Unreferenced, KeyLifeCycle::Existing], ) .context("Failed to execute query.") .need_gc() }) .context(ks_err!()) } /// Checks if a key exists with given key type and key descriptor properties. pub fn key_exists( &mut self, domain: Domain, nspace: i64, alias: &str, key_type: KeyType, ) -> Result { let _wp = wd::watch("KeystoreDB::key_exists"); self.with_transaction(Immediate("TX_key_exists"), |tx| { let key_descriptor = KeyDescriptor { domain, nspace, alias: Some(alias.to_string()), blob: None }; let result = Self::load_key_entry_id(tx, &key_descriptor, key_type); match result { Ok(_) => Ok(true), Err(error) => match error.root_cause().downcast_ref::() { Some(KsError::Rc(ResponseCode::KEY_NOT_FOUND)) => Ok(false), _ => Err(error).context(ks_err!("Failed to find if the key exists.")), }, } .no_gc() }) .context(ks_err!()) } /// Stores a super key in the database. pub fn store_super_key( &mut self, user_id: u32, key_type: &SuperKeyType, blob: &[u8], blob_metadata: &BlobMetaData, key_metadata: &KeyMetaData, ) -> Result { let _wp = wd::watch("KeystoreDB::store_super_key"); self.with_transaction(Immediate("TX_store_super_key"), |tx| { let key_id = Self::insert_with_retry(|id| { tx.execute( "INSERT into persistent.keyentry (id, key_type, domain, namespace, alias, state, km_uuid) VALUES(?, ?, ?, ?, ?, ?, ?);", params![ id, KeyType::Super, Domain::APP.0, user_id as i64, key_type.alias, KeyLifeCycle::Live, &KEYSTORE_UUID, ], ) }) .context("Failed to insert into keyentry table.")?; key_metadata.store_in_db(key_id, tx).context("KeyMetaData::store_in_db failed")?; Self::set_blob_internal( tx, key_id, SubComponentType::KEY_BLOB, Some(blob), Some(blob_metadata), ) .context("Failed to store key blob.")?; Self::load_key_components(tx, KeyEntryLoadBits::KM, key_id) .context("Trying to load key components.") .no_gc() }) .context(ks_err!()) } /// Loads super key of a given user, if exists pub fn load_super_key( &mut self, key_type: &SuperKeyType, user_id: u32, ) -> Result> { let _wp = wd::watch("KeystoreDB::load_super_key"); self.with_transaction(Immediate("TX_load_super_key"), |tx| { let key_descriptor = KeyDescriptor { domain: Domain::APP, nspace: user_id as i64, alias: Some(key_type.alias.into()), blob: None, }; let id = Self::load_key_entry_id(tx, &key_descriptor, KeyType::Super); match id { Ok(id) => { let key_entry = Self::load_key_components(tx, KeyEntryLoadBits::KM, id) .context(ks_err!("Failed to load key entry."))?; Ok(Some((KEY_ID_LOCK.get(id), key_entry))) } Err(error) => match error.root_cause().downcast_ref::() { Some(KsError::Rc(ResponseCode::KEY_NOT_FOUND)) => Ok(None), _ => Err(error).context(ks_err!()), }, } .no_gc() }) .context(ks_err!()) } /// Creates a transaction with the given behavior and executes f with the new transaction. /// The transaction is committed only if f returns Ok and retried if DatabaseBusy /// or DatabaseLocked is encountered. fn with_transaction(&mut self, behavior: TransactionBehavior, f: F) -> Result where F: Fn(&Transaction) -> Result<(bool, T)>, { let name = behavior.name(); loop { let result = self .conn .transaction_with_behavior(behavior.into()) .context(ks_err!()) .and_then(|tx| { let _wp = name.map(wd::watch); f(&tx).map(|result| (result, tx)) }) .and_then(|(result, tx)| { tx.commit().context(ks_err!("Failed to commit transaction."))?; Ok(result) }); match result { Ok(result) => break Ok(result), Err(e) => { if Self::is_locked_error(&e) { std::thread::sleep(DB_BUSY_RETRY_INTERVAL); continue; } else { return Err(e).context(ks_err!()); } } } } .map(|(need_gc, result)| { if need_gc { if let Some(ref gc) = self.gc { gc.notify_gc(); } } result }) } fn is_locked_error(e: &anyhow::Error) -> bool { matches!( e.root_cause().downcast_ref::(), Some(rusqlite::ffi::Error { code: rusqlite::ErrorCode::DatabaseBusy, .. }) | Some(rusqlite::ffi::Error { code: rusqlite::ErrorCode::DatabaseLocked, .. }) ) } fn create_key_entry_internal( tx: &Transaction, domain: &Domain, namespace: &i64, key_type: KeyType, km_uuid: &Uuid, ) -> Result { match *domain { Domain::APP | Domain::SELINUX => {} _ => { return Err(KsError::sys()) .context(ks_err!("Domain {:?} must be either App or SELinux.", domain)); } } Ok(KEY_ID_LOCK.get( Self::insert_with_retry(|id| { tx.execute( "INSERT into persistent.keyentry (id, key_type, domain, namespace, alias, state, km_uuid) VALUES(?, ?, ?, ?, NULL, ?, ?);", params![ id, key_type, domain.0 as u32, *namespace, KeyLifeCycle::Existing, km_uuid, ], ) }) .context(ks_err!())?, )) } /// Set a new blob and associates it with the given key id. Each blob /// has a sub component type. /// Each key can have one of each sub component type associated. If more /// are added only the most recent can be retrieved, and superseded blobs /// will get garbage collected. /// Components SubComponentType::CERT and SubComponentType::CERT_CHAIN can be /// removed by setting blob to None. pub fn set_blob( &mut self, key_id: &KeyIdGuard, sc_type: SubComponentType, blob: Option<&[u8]>, blob_metadata: Option<&BlobMetaData>, ) -> Result<()> { let _wp = wd::watch("KeystoreDB::set_blob"); self.with_transaction(Immediate("TX_set_blob"), |tx| { Self::set_blob_internal(tx, key_id.0, sc_type, blob, blob_metadata).need_gc() }) .context(ks_err!()) } /// Why would we insert a deleted blob? This weird function is for the purpose of legacy /// key migration in the case where we bulk delete all the keys of an app or even a user. /// We use this to insert key blobs into the database which can then be garbage collected /// lazily by the key garbage collector. pub fn set_deleted_blob(&mut self, blob: &[u8], blob_metadata: &BlobMetaData) -> Result<()> { let _wp = wd::watch("KeystoreDB::set_deleted_blob"); self.with_transaction(Immediate("TX_set_deleted_blob"), |tx| { Self::set_blob_internal( tx, Self::UNASSIGNED_KEY_ID, SubComponentType::KEY_BLOB, Some(blob), Some(blob_metadata), ) .need_gc() }) .context(ks_err!()) } fn set_blob_internal( tx: &Transaction, key_id: i64, sc_type: SubComponentType, blob: Option<&[u8]>, blob_metadata: Option<&BlobMetaData>, ) -> Result<()> { match (blob, sc_type) { (Some(blob), _) => { // Mark any previous blobentry(s) of the same type for the same key as superseded. tx.execute( "UPDATE persistent.blobentry SET state = ? WHERE keyentryid = ? AND subcomponent_type = ?", params![BlobState::Superseded, key_id, sc_type], ) .context(ks_err!( "Failed to mark prior {sc_type:?} blobentrys for {key_id} as superseded" ))?; // Now insert the new, un-superseded, blob. (If this fails, the marking of // old blobs as superseded will be rolled back, because we're inside a // transaction.) tx.execute( "INSERT INTO persistent.blobentry (subcomponent_type, keyentryid, blob) VALUES (?, ?, ?);", params![sc_type, key_id, blob], ) .context(ks_err!("Failed to insert blob."))?; if let Some(blob_metadata) = blob_metadata { let blob_id = tx .query_row("SELECT MAX(id) FROM persistent.blobentry;", [], |row| { row.get(0) }) .context(ks_err!("Failed to get new blob id."))?; blob_metadata .store_in_db(blob_id, tx) .context(ks_err!("Trying to store blob metadata."))?; } } (None, SubComponentType::CERT) | (None, SubComponentType::CERT_CHAIN) => { tx.execute( "DELETE FROM persistent.blobentry WHERE subcomponent_type = ? AND keyentryid = ?;", params![sc_type, key_id], ) .context(ks_err!("Failed to delete blob."))?; } (None, _) => { return Err(KsError::sys()) .context(ks_err!("Other blobs cannot be deleted in this way.")); } } Ok(()) } /// Inserts a collection of key parameters into the `persistent.keyparameter` table /// and associates them with the given `key_id`. #[cfg(test)] fn insert_keyparameter(&mut self, key_id: &KeyIdGuard, params: &[KeyParameter]) -> Result<()> { self.with_transaction(Immediate("TX_insert_keyparameter"), |tx| { Self::insert_keyparameter_internal(tx, key_id, params).no_gc() }) .context(ks_err!()) } fn insert_keyparameter_internal( tx: &Transaction, key_id: &KeyIdGuard, params: &[KeyParameter], ) -> Result<()> { let mut stmt = tx .prepare( "INSERT into persistent.keyparameter (keyentryid, tag, data, security_level) VALUES (?, ?, ?, ?);", ) .context(ks_err!("Failed to prepare statement."))?; for p in params.iter() { stmt.insert(params![ key_id.0, p.get_tag().0, p.key_parameter_value(), p.security_level().0 ]) .with_context(|| ks_err!("Failed to insert {:?}", p))?; } Ok(()) } /// Insert a set of key entry specific metadata into the database. #[cfg(test)] fn insert_key_metadata(&mut self, key_id: &KeyIdGuard, metadata: &KeyMetaData) -> Result<()> { self.with_transaction(Immediate("TX_insert_key_metadata"), |tx| { metadata.store_in_db(key_id.0, tx).no_gc() }) .context(ks_err!()) } /// Updates the alias column of the given key id `newid` with the given alias, /// and atomically, removes the alias, domain, and namespace from another row /// with the same alias-domain-namespace tuple if such row exits. /// Returns Ok(true) if an old key was marked unreferenced as a hint to the garbage /// collector. fn rebind_alias( tx: &Transaction, newid: &KeyIdGuard, alias: &str, domain: &Domain, namespace: &i64, key_type: KeyType, ) -> Result { match *domain { Domain::APP | Domain::SELINUX => {} _ => { return Err(KsError::sys()) .context(ks_err!("Domain {:?} must be either App or SELinux.", domain)); } } let updated = tx .execute( "UPDATE persistent.keyentry SET alias = NULL, domain = NULL, namespace = NULL, state = ? WHERE alias = ? AND domain = ? AND namespace = ? AND key_type = ?;", params![KeyLifeCycle::Unreferenced, alias, domain.0 as u32, namespace, key_type], ) .context(ks_err!("Failed to rebind existing entry."))?; let result = tx .execute( "UPDATE persistent.keyentry SET alias = ?, state = ? WHERE id = ? AND domain = ? AND namespace = ? AND state = ? AND key_type = ?;", params![ alias, KeyLifeCycle::Live, newid.0, domain.0 as u32, *namespace, KeyLifeCycle::Existing, key_type, ], ) .context(ks_err!("Failed to set alias."))?; if result != 1 { return Err(KsError::sys()).context(ks_err!( "Expected to update a single entry but instead updated {}.", result )); } Ok(updated != 0) } /// Moves the key given by KeyIdGuard to the new location at `destination`. If the destination /// is already occupied by a key, this function fails with `ResponseCode::INVALID_ARGUMENT`. pub fn migrate_key_namespace( &mut self, key_id_guard: KeyIdGuard, destination: &KeyDescriptor, caller_uid: u32, check_permission: impl Fn(&KeyDescriptor) -> Result<()>, ) -> Result<()> { let _wp = wd::watch("KeystoreDB::migrate_key_namespace"); let destination = match destination.domain { Domain::APP => KeyDescriptor { nspace: caller_uid as i64, ..(*destination).clone() }, Domain::SELINUX => (*destination).clone(), domain => { return Err(KsError::Rc(ResponseCode::INVALID_ARGUMENT)) .context(format!("Domain {:?} must be either APP or SELINUX.", domain)); } }; // Security critical: Must return immediately on failure. Do not remove the '?'; check_permission(&destination).context(ks_err!("Trying to check permission."))?; let alias = destination .alias .as_ref() .ok_or(KsError::Rc(ResponseCode::INVALID_ARGUMENT)) .context(ks_err!("Alias must be specified."))?; self.with_transaction(Immediate("TX_migrate_key_namespace"), |tx| { // Query the destination location. If there is a key, the migration request fails. if tx .query_row( "SELECT id FROM persistent.keyentry WHERE alias = ? AND domain = ? AND namespace = ?;", params![alias, destination.domain.0, destination.nspace], |_| Ok(()), ) .optional() .context("Failed to query destination.")? .is_some() { return Err(KsError::Rc(ResponseCode::INVALID_ARGUMENT)) .context("Target already exists."); } let updated = tx .execute( "UPDATE persistent.keyentry SET alias = ?, domain = ?, namespace = ? WHERE id = ?;", params![alias, destination.domain.0, destination.nspace, key_id_guard.id()], ) .context("Failed to update key entry.")?; if updated != 1 { return Err(KsError::sys()) .context(format!("Update succeeded, but {} rows were updated.", updated)); } Ok(()).no_gc() }) .context(ks_err!()) } /// Store a new key in a single transaction. /// The function creates a new key entry, populates the blob, key parameter, and metadata /// fields, and rebinds the given alias to the new key. /// The boolean returned is a hint for the garbage collector. If true, a key was replaced, /// is now unreferenced and needs to be collected. #[allow(clippy::too_many_arguments)] pub fn store_new_key( &mut self, key: &KeyDescriptor, key_type: KeyType, params: &[KeyParameter], blob_info: &BlobInfo, cert_info: &CertificateInfo, metadata: &KeyMetaData, km_uuid: &Uuid, ) -> Result { let _wp = wd::watch("KeystoreDB::store_new_key"); let (alias, domain, namespace) = match key { KeyDescriptor { alias: Some(alias), domain: Domain::APP, nspace, blob: None } | KeyDescriptor { alias: Some(alias), domain: Domain::SELINUX, nspace, blob: None } => { (alias, key.domain, nspace) } _ => { return Err(KsError::Rc(ResponseCode::INVALID_ARGUMENT)) .context(ks_err!("Need alias and domain must be APP or SELINUX.")); } }; self.with_transaction(Immediate("TX_store_new_key"), |tx| { let key_id = Self::create_key_entry_internal(tx, &domain, namespace, key_type, km_uuid) .context("Trying to create new key entry.")?; let BlobInfo { blob, metadata: blob_metadata, superseded_blob } = *blob_info; // In some occasions the key blob is already upgraded during the import. // In order to make sure it gets properly deleted it is inserted into the // database here and then immediately replaced by the superseding blob. // The garbage collector will then subject the blob to deleteKey of the // KM back end to permanently invalidate the key. let need_gc = if let Some((blob, blob_metadata)) = superseded_blob { Self::set_blob_internal( tx, key_id.id(), SubComponentType::KEY_BLOB, Some(blob), Some(blob_metadata), ) .context("Trying to insert superseded key blob.")?; true } else { false }; Self::set_blob_internal( tx, key_id.id(), SubComponentType::KEY_BLOB, Some(blob), Some(blob_metadata), ) .context("Trying to insert the key blob.")?; if let Some(cert) = &cert_info.cert { Self::set_blob_internal(tx, key_id.id(), SubComponentType::CERT, Some(cert), None) .context("Trying to insert the certificate.")?; } if let Some(cert_chain) = &cert_info.cert_chain { Self::set_blob_internal( tx, key_id.id(), SubComponentType::CERT_CHAIN, Some(cert_chain), None, ) .context("Trying to insert the certificate chain.")?; } Self::insert_keyparameter_internal(tx, &key_id, params) .context("Trying to insert key parameters.")?; metadata.store_in_db(key_id.id(), tx).context("Trying to insert key metadata.")?; let need_gc = Self::rebind_alias(tx, &key_id, alias, &domain, namespace, key_type) .context("Trying to rebind alias.")? || need_gc; Ok(key_id).do_gc(need_gc) }) .context(ks_err!()) } /// Store a new certificate /// The function creates a new key entry, populates the blob field and metadata, and rebinds /// the given alias to the new cert. pub fn store_new_certificate( &mut self, key: &KeyDescriptor, key_type: KeyType, cert: &[u8], km_uuid: &Uuid, ) -> Result { let _wp = wd::watch("KeystoreDB::store_new_certificate"); let (alias, domain, namespace) = match key { KeyDescriptor { alias: Some(alias), domain: Domain::APP, nspace, blob: None } | KeyDescriptor { alias: Some(alias), domain: Domain::SELINUX, nspace, blob: None } => { (alias, key.domain, nspace) } _ => { return Err(KsError::Rc(ResponseCode::INVALID_ARGUMENT)) .context(ks_err!("Need alias and domain must be APP or SELINUX.")); } }; self.with_transaction(Immediate("TX_store_new_certificate"), |tx| { let key_id = Self::create_key_entry_internal(tx, &domain, namespace, key_type, km_uuid) .context("Trying to create new key entry.")?; Self::set_blob_internal( tx, key_id.id(), SubComponentType::CERT_CHAIN, Some(cert), None, ) .context("Trying to insert certificate.")?; let mut metadata = KeyMetaData::new(); metadata.add(KeyMetaEntry::CreationDate( DateTime::now().context("Trying to make creation time.")?, )); metadata.store_in_db(key_id.id(), tx).context("Trying to insert key metadata.")?; let need_gc = Self::rebind_alias(tx, &key_id, alias, &domain, namespace, key_type) .context("Trying to rebind alias.")?; Ok(key_id).do_gc(need_gc) }) .context(ks_err!()) } // Helper function loading the key_id given the key descriptor // tuple comprising domain, namespace, and alias. // Requires a valid transaction. fn load_key_entry_id(tx: &Transaction, key: &KeyDescriptor, key_type: KeyType) -> Result { let alias = key .alias .as_ref() .map_or_else(|| Err(KsError::sys()), Ok) .context("In load_key_entry_id: Alias must be specified.")?; let mut stmt = tx .prepare( "SELECT id FROM persistent.keyentry WHERE key_type = ? AND domain = ? AND namespace = ? AND alias = ? AND state = ?;", ) .context("In load_key_entry_id: Failed to select from keyentry table.")?; let mut rows = stmt .query(params![key_type, key.domain.0 as u32, key.nspace, alias, KeyLifeCycle::Live]) .context("In load_key_entry_id: Failed to read from keyentry table.")?; db_utils::with_rows_extract_one(&mut rows, |row| { row.map_or_else(|| Err(KsError::Rc(ResponseCode::KEY_NOT_FOUND)), Ok)? .get(0) .context("Failed to unpack id.") }) .context(ks_err!()) } /// This helper function completes the access tuple of a key, which is required /// to perform access control. The strategy depends on the `domain` field in the /// key descriptor. /// * Domain::SELINUX: The access tuple is complete and this function only loads /// the key_id for further processing. /// * Domain::APP: Like Domain::SELINUX, but the tuple is completed by `caller_uid` /// which serves as the namespace. /// * Domain::GRANT: The grant table is queried for the `key_id` and the /// `access_vector`. /// * Domain::KEY_ID: The keyentry table is queried for the owning `domain` and /// `namespace`. /// /// In each case the information returned is sufficient to perform the access /// check and the key id can be used to load further key artifacts. fn load_access_tuple( tx: &Transaction, key: &KeyDescriptor, key_type: KeyType, caller_uid: u32, ) -> Result { match key.domain { // Domain App or SELinux. In this case we load the key_id from // the keyentry database for further loading of key components. // We already have the full access tuple to perform access control. // The only distinction is that we use the caller_uid instead // of the caller supplied namespace if the domain field is // Domain::APP. Domain::APP | Domain::SELINUX => { let mut access_key = key.clone(); if access_key.domain == Domain::APP { access_key.nspace = caller_uid as i64; } let key_id = Self::load_key_entry_id(tx, &access_key, key_type) .with_context(|| format!("With key.domain = {:?}.", access_key.domain))?; Ok(KeyAccessInfo { key_id, descriptor: access_key, vector: None }) } // Domain::GRANT. In this case we load the key_id and the access_vector // from the grant table. Domain::GRANT => { let mut stmt = tx .prepare( "SELECT keyentryid, access_vector FROM persistent.grant WHERE grantee = ? AND id = ? AND (SELECT state FROM persistent.keyentry WHERE id = keyentryid) = ?;", ) .context("Domain::GRANT prepare statement failed")?; let mut rows = stmt .query(params![caller_uid as i64, key.nspace, KeyLifeCycle::Live]) .context("Domain:Grant: query failed.")?; let (key_id, access_vector): (i64, i32) = db_utils::with_rows_extract_one(&mut rows, |row| { let r = row.map_or_else(|| Err(KsError::Rc(ResponseCode::KEY_NOT_FOUND)), Ok)?; Ok(( r.get(0).context("Failed to unpack key_id.")?, r.get(1).context("Failed to unpack access_vector.")?, )) }) .context("Domain::GRANT.")?; Ok(KeyAccessInfo { key_id, descriptor: key.clone(), vector: Some(access_vector.into()), }) } // Domain::KEY_ID. In this case we load the domain and namespace from the // keyentry database because we need them for access control. Domain::KEY_ID => { let (domain, namespace): (Domain, i64) = { let mut stmt = tx .prepare( "SELECT domain, namespace FROM persistent.keyentry WHERE id = ? AND state = ?;", ) .context("Domain::KEY_ID: prepare statement failed")?; let mut rows = stmt .query(params![key.nspace, KeyLifeCycle::Live]) .context("Domain::KEY_ID: query failed.")?; db_utils::with_rows_extract_one(&mut rows, |row| { let r = row.map_or_else(|| Err(KsError::Rc(ResponseCode::KEY_NOT_FOUND)), Ok)?; Ok(( Domain(r.get(0).context("Failed to unpack domain.")?), r.get(1).context("Failed to unpack namespace.")?, )) }) .context("Domain::KEY_ID.")? }; // We may use a key by id after loading it by grant. // In this case we have to check if the caller has a grant for this particular // key. We can skip this if we already know that the caller is the owner. // But we cannot know this if domain is anything but App. E.g. in the case // of Domain::SELINUX we have to speculatively check for grants because we have to // consult the SEPolicy before we know if the caller is the owner. let access_vector: Option = if domain != Domain::APP || namespace != caller_uid as i64 { let access_vector: Option = tx .query_row( "SELECT access_vector FROM persistent.grant WHERE grantee = ? AND keyentryid = ?;", params![caller_uid as i64, key.nspace], |row| row.get(0), ) .optional() .context("Domain::KEY_ID: query grant failed.")?; access_vector.map(|p| p.into()) } else { None }; let key_id = key.nspace; let mut access_key: KeyDescriptor = key.clone(); access_key.domain = domain; access_key.nspace = namespace; Ok(KeyAccessInfo { key_id, descriptor: access_key, vector: access_vector }) } _ => Err(anyhow!(KsError::Rc(ResponseCode::INVALID_ARGUMENT))), } } fn load_blob_components( key_id: i64, load_bits: KeyEntryLoadBits, tx: &Transaction, ) -> Result<(bool, Option<(Vec, BlobMetaData)>, Option>, Option>)> { let mut stmt = tx .prepare( "SELECT MAX(id), subcomponent_type, blob FROM persistent.blobentry WHERE keyentryid = ? GROUP BY subcomponent_type;", ) .context(ks_err!("prepare statement failed."))?; let mut rows = stmt.query(params![key_id]).context(ks_err!("query failed."))?; let mut key_blob: Option<(i64, Vec)> = None; let mut cert_blob: Option> = None; let mut cert_chain_blob: Option> = None; let mut has_km_blob: bool = false; db_utils::with_rows_extract_all(&mut rows, |row| { let sub_type: SubComponentType = row.get(1).context("Failed to extract subcomponent_type.")?; has_km_blob = has_km_blob || sub_type == SubComponentType::KEY_BLOB; match (sub_type, load_bits.load_public(), load_bits.load_km()) { (SubComponentType::KEY_BLOB, _, true) => { key_blob = Some(( row.get(0).context("Failed to extract key blob id.")?, row.get(2).context("Failed to extract key blob.")?, )); } (SubComponentType::CERT, true, _) => { cert_blob = Some(row.get(2).context("Failed to extract public certificate blob.")?); } (SubComponentType::CERT_CHAIN, true, _) => { cert_chain_blob = Some(row.get(2).context("Failed to extract certificate chain blob.")?); } (SubComponentType::CERT, _, _) | (SubComponentType::CERT_CHAIN, _, _) | (SubComponentType::KEY_BLOB, _, _) => {} _ => Err(KsError::sys()).context("Unknown subcomponent type.")?, } Ok(()) }) .context(ks_err!())?; let blob_info = key_blob.map_or::, _>(Ok(None), |(blob_id, blob)| { Ok(Some(( blob, BlobMetaData::load_from_db(blob_id, tx) .context(ks_err!("Trying to load blob_metadata."))?, ))) })?; Ok((has_km_blob, blob_info, cert_blob, cert_chain_blob)) } fn load_key_parameters(key_id: i64, tx: &Transaction) -> Result> { let mut stmt = tx .prepare( "SELECT tag, data, security_level from persistent.keyparameter WHERE keyentryid = ?;", ) .context("In load_key_parameters: prepare statement failed.")?; let mut parameters: Vec = Vec::new(); let mut rows = stmt.query(params![key_id]).context("In load_key_parameters: query failed.")?; db_utils::with_rows_extract_all(&mut rows, |row| { let tag = Tag(row.get(0).context("Failed to read tag.")?); let sec_level = SecurityLevel(row.get(2).context("Failed to read sec_level.")?); parameters.push( KeyParameter::new_from_sql(tag, &SqlField::new(1, row), sec_level) .context("Failed to read KeyParameter.")?, ); Ok(()) }) .context(ks_err!())?; Ok(parameters) } /// Decrements the usage count of a limited use key. This function first checks whether the /// usage has been exhausted, if not, decreases the usage count. If the usage count reaches /// zero, the key also gets marked unreferenced and scheduled for deletion. /// Returns Ok(true) if the key was marked unreferenced as a hint to the garbage collector. pub fn check_and_update_key_usage_count(&mut self, key_id: i64) -> Result<()> { let _wp = wd::watch("KeystoreDB::check_and_update_key_usage_count"); self.with_transaction(Immediate("TX_check_and_update_key_usage_count"), |tx| { let limit: Option = tx .query_row( "SELECT data FROM persistent.keyparameter WHERE keyentryid = ? AND tag = ?;", params![key_id, Tag::USAGE_COUNT_LIMIT.0], |row| row.get(0), ) .optional() .context("Trying to load usage count")?; let limit = limit .ok_or(KsError::Km(ErrorCode::INVALID_KEY_BLOB)) .context("The Key no longer exists. Key is exhausted.")?; tx.execute( "UPDATE persistent.keyparameter SET data = data - 1 WHERE keyentryid = ? AND tag = ? AND data > 0;", params![key_id, Tag::USAGE_COUNT_LIMIT.0], ) .context("Failed to update key usage count.")?; match limit { 1 => Self::mark_unreferenced(tx, key_id) .map(|need_gc| (need_gc, ())) .context("Trying to mark limited use key for deletion."), 0 => Err(KsError::Km(ErrorCode::INVALID_KEY_BLOB)).context("Key is exhausted."), _ => Ok(()).no_gc(), } }) .context(ks_err!()) } /// Load a key entry by the given key descriptor. /// It uses the `check_permission` callback to verify if the access is allowed /// given the key access tuple read from the database using `load_access_tuple`. /// With `load_bits` the caller may specify which blobs shall be loaded from /// the blob database. pub fn load_key_entry( &mut self, key: &KeyDescriptor, key_type: KeyType, load_bits: KeyEntryLoadBits, caller_uid: u32, check_permission: impl Fn(&KeyDescriptor, Option) -> Result<()>, ) -> Result<(KeyIdGuard, KeyEntry)> { let _wp = wd::watch("KeystoreDB::load_key_entry"); loop { match self.load_key_entry_internal( key, key_type, load_bits, caller_uid, &check_permission, ) { Ok(result) => break Ok(result), Err(e) => { if Self::is_locked_error(&e) { std::thread::sleep(DB_BUSY_RETRY_INTERVAL); continue; } else { return Err(e).context(ks_err!()); } } } } } fn load_key_entry_internal( &mut self, key: &KeyDescriptor, key_type: KeyType, load_bits: KeyEntryLoadBits, caller_uid: u32, check_permission: &impl Fn(&KeyDescriptor, Option) -> Result<()>, ) -> Result<(KeyIdGuard, KeyEntry)> { // KEY ID LOCK 1/2 // If we got a key descriptor with a key id we can get the lock right away. // Otherwise we have to defer it until we know the key id. let key_id_guard = match key.domain { Domain::KEY_ID => Some(KEY_ID_LOCK.get(key.nspace)), _ => None, }; let tx = self .conn .unchecked_transaction() .context(ks_err!("Failed to initialize transaction."))?; // Load the key_id and complete the access control tuple. let access = Self::load_access_tuple(&tx, key, key_type, caller_uid).context(ks_err!())?; // Perform access control. It is vital that we return here if the permission is denied. // So do not touch that '?' at the end. check_permission(&access.descriptor, access.vector).context(ks_err!())?; // KEY ID LOCK 2/2 // If we did not get a key id lock by now, it was because we got a key descriptor // without a key id. At this point we got the key id, so we can try and get a lock. // However, we cannot block here, because we are in the middle of the transaction. // So first we try to get the lock non blocking. If that fails, we roll back the // transaction and block until we get the lock. After we successfully got the lock, // we start a new transaction and load the access tuple again. // // We don't need to perform access control again, because we already established // that the caller had access to the given key. But we need to make sure that the // key id still exists. So we have to load the key entry by key id this time. let (key_id_guard, tx) = match key_id_guard { None => match KEY_ID_LOCK.try_get(access.key_id) { None => { // Roll back the transaction. tx.rollback().context(ks_err!("Failed to roll back transaction."))?; // Block until we have a key id lock. let key_id_guard = KEY_ID_LOCK.get(access.key_id); // Create a new transaction. let tx = self .conn .unchecked_transaction() .context(ks_err!("Failed to initialize transaction."))?; Self::load_access_tuple( &tx, // This time we have to load the key by the retrieved key id, because the // alias may have been rebound after we rolled back the transaction. &KeyDescriptor { domain: Domain::KEY_ID, nspace: access.key_id, ..Default::default() }, key_type, caller_uid, ) .context(ks_err!("(deferred key lock)"))?; (key_id_guard, tx) } Some(l) => (l, tx), }, Some(key_id_guard) => (key_id_guard, tx), }; let key_entry = Self::load_key_components(&tx, load_bits, key_id_guard.id()).context(ks_err!())?; tx.commit().context(ks_err!("Failed to commit transaction."))?; Ok((key_id_guard, key_entry)) } fn mark_unreferenced(tx: &Transaction, key_id: i64) -> Result { let updated = tx .execute("DELETE FROM persistent.keyentry WHERE id = ?;", params![key_id]) .context("Trying to delete keyentry.")?; tx.execute("DELETE FROM persistent.keymetadata WHERE keyentryid = ?;", params![key_id]) .context("Trying to delete keymetadata.")?; tx.execute("DELETE FROM persistent.keyparameter WHERE keyentryid = ?;", params![key_id]) .context("Trying to delete keyparameters.")?; tx.execute("DELETE FROM persistent.grant WHERE keyentryid = ?;", params![key_id]) .context("Trying to delete grants.")?; // The associated blobentry rows are not immediately deleted when the owning keyentry is // removed, because a KeyMint `deleteKey()` invocation is needed (specifically for the // `KEY_BLOB`). Mark the affected rows with `state=Orphaned` so a subsequent garbage // collection can do this. tx.execute( "UPDATE persistent.blobentry SET state = ? WHERE keyentryid = ?", params![BlobState::Orphaned, key_id], ) .context("Trying to mark blobentrys as superseded")?; Ok(updated != 0) } /// Marks the given key as unreferenced and removes all of the grants to this key. /// Returns Ok(true) if a key was marked unreferenced as a hint for the garbage collector. pub fn unbind_key( &mut self, key: &KeyDescriptor, key_type: KeyType, caller_uid: u32, check_permission: impl Fn(&KeyDescriptor, Option) -> Result<()>, ) -> Result<()> { let _wp = wd::watch("KeystoreDB::unbind_key"); self.with_transaction(Immediate("TX_unbind_key"), |tx| { let access = Self::load_access_tuple(tx, key, key_type, caller_uid) .context("Trying to get access tuple.")?; // Perform access control. It is vital that we return here if the permission is denied. // So do not touch that '?' at the end. check_permission(&access.descriptor, access.vector) .context("While checking permission.")?; Self::mark_unreferenced(tx, access.key_id) .map(|need_gc| (need_gc, ())) .context("Trying to mark the key unreferenced.") }) .context(ks_err!()) } fn get_key_km_uuid(tx: &Transaction, key_id: i64) -> Result { tx.query_row( "SELECT km_uuid FROM persistent.keyentry WHERE id = ?", params![key_id], |row| row.get(0), ) .context(ks_err!()) } /// Delete all artifacts belonging to the namespace given by the domain-namespace tuple. /// This leaves all of the blob entries orphaned for subsequent garbage collection. pub fn unbind_keys_for_namespace(&mut self, domain: Domain, namespace: i64) -> Result<()> { let _wp = wd::watch("KeystoreDB::unbind_keys_for_namespace"); if !(domain == Domain::APP || domain == Domain::SELINUX) { return Err(KsError::Rc(ResponseCode::INVALID_ARGUMENT)).context(ks_err!()); } self.with_transaction(Immediate("TX_unbind_keys_for_namespace"), |tx| { tx.execute( "DELETE FROM persistent.keymetadata WHERE keyentryid IN ( SELECT id FROM persistent.keyentry WHERE domain = ? AND namespace = ? AND key_type = ? );", params![domain.0, namespace, KeyType::Client], ) .context("Trying to delete keymetadata.")?; tx.execute( "DELETE FROM persistent.keyparameter WHERE keyentryid IN ( SELECT id FROM persistent.keyentry WHERE domain = ? AND namespace = ? AND key_type = ? );", params![domain.0, namespace, KeyType::Client], ) .context("Trying to delete keyparameters.")?; tx.execute( "DELETE FROM persistent.grant WHERE keyentryid IN ( SELECT id FROM persistent.keyentry WHERE domain = ? AND namespace = ? AND key_type = ? );", params![domain.0, namespace, KeyType::Client], ) .context("Trying to delete grants.")?; tx.execute( "DELETE FROM persistent.keyentry WHERE domain = ? AND namespace = ? AND key_type = ?;", params![domain.0, namespace, KeyType::Client], ) .context("Trying to delete keyentry.")?; Ok(()).need_gc() }) .context(ks_err!()) } fn cleanup_unreferenced(tx: &Transaction) -> Result<()> { let _wp = wd::watch("KeystoreDB::cleanup_unreferenced"); { tx.execute( "DELETE FROM persistent.keymetadata WHERE keyentryid IN ( SELECT id FROM persistent.keyentry WHERE state = ? );", params![KeyLifeCycle::Unreferenced], ) .context("Trying to delete keymetadata.")?; tx.execute( "DELETE FROM persistent.keyparameter WHERE keyentryid IN ( SELECT id FROM persistent.keyentry WHERE state = ? );", params![KeyLifeCycle::Unreferenced], ) .context("Trying to delete keyparameters.")?; tx.execute( "DELETE FROM persistent.grant WHERE keyentryid IN ( SELECT id FROM persistent.keyentry WHERE state = ? );", params![KeyLifeCycle::Unreferenced], ) .context("Trying to delete grants.")?; tx.execute( "DELETE FROM persistent.keyentry WHERE state = ?;", params![KeyLifeCycle::Unreferenced], ) .context("Trying to delete keyentry.")?; Result::<()>::Ok(()) } .context(ks_err!()) } /// Deletes all keys for the given user, including both client keys and super keys. pub fn unbind_keys_for_user(&mut self, user_id: u32) -> Result<()> { let _wp = wd::watch("KeystoreDB::unbind_keys_for_user"); self.with_transaction(Immediate("TX_unbind_keys_for_user"), |tx| { let mut stmt = tx .prepare(&format!( "SELECT id from persistent.keyentry WHERE ( key_type = ? AND domain = ? AND cast ( (namespace/{aid_user_offset}) as int) = ? AND state = ? ) OR ( key_type = ? AND namespace = ? AND state = ? );", aid_user_offset = AID_USER_OFFSET )) .context(concat!( "In unbind_keys_for_user. ", "Failed to prepare the query to find the keys created by apps." ))?; let mut rows = stmt .query(params![ // WHERE client key: KeyType::Client, Domain::APP.0 as u32, user_id, KeyLifeCycle::Live, // OR super key: KeyType::Super, user_id, KeyLifeCycle::Live ]) .context(ks_err!("Failed to query the keys created by apps."))?; let mut key_ids: Vec = Vec::new(); db_utils::with_rows_extract_all(&mut rows, |row| { key_ids .push(row.get(0).context("Failed to read key id of a key created by an app.")?); Ok(()) }) .context(ks_err!())?; let mut notify_gc = false; for key_id in key_ids { notify_gc = Self::mark_unreferenced(tx, key_id) .context("In unbind_keys_for_user.")? || notify_gc; } Ok(()).do_gc(notify_gc) }) .context(ks_err!()) } /// Deletes all auth-bound keys, i.e. keys that require user authentication, for the given user. /// This runs when the user's lock screen is being changed to Swipe or None. /// /// This intentionally does *not* delete keys that require that the device be unlocked, unless /// such keys also require user authentication. Keystore's concept of user authentication is /// fairly strong, and it requires that keys that require authentication be deleted as soon as /// authentication is no longer possible. In contrast, keys that just require that the device /// be unlocked should remain usable when the lock screen is set to Swipe or None, as the device /// is always considered "unlocked" in that case. pub fn unbind_auth_bound_keys_for_user(&mut self, user_id: u32) -> Result<()> { let _wp = wd::watch("KeystoreDB::unbind_auth_bound_keys_for_user"); self.with_transaction(Immediate("TX_unbind_auth_bound_keys_for_user"), |tx| { let mut stmt = tx .prepare(&format!( "SELECT id from persistent.keyentry WHERE key_type = ? AND domain = ? AND cast ( (namespace/{aid_user_offset}) as int) = ? AND state = ?;", aid_user_offset = AID_USER_OFFSET )) .context(concat!( "In unbind_auth_bound_keys_for_user. ", "Failed to prepare the query to find the keys created by apps." ))?; let mut rows = stmt .query(params![KeyType::Client, Domain::APP.0 as u32, user_id, KeyLifeCycle::Live,]) .context(ks_err!("Failed to query the keys created by apps."))?; let mut key_ids: Vec = Vec::new(); db_utils::with_rows_extract_all(&mut rows, |row| { key_ids .push(row.get(0).context("Failed to read key id of a key created by an app.")?); Ok(()) }) .context(ks_err!())?; let mut notify_gc = false; let mut num_unbound = 0; for key_id in key_ids { // Load the key parameters and filter out non-auth-bound keys. To identify // auth-bound keys, use the presence of UserSecureID. The absence of NoAuthRequired // could also be used, but UserSecureID is what Keystore treats as authoritative // when actually enforcing the key parameters (it might not matter, though). let params = Self::load_key_parameters(key_id, tx) .context("Failed to load key parameters.")?; let is_auth_bound_key = params.iter().any(|kp| { matches!(kp.key_parameter_value(), KeyParameterValue::UserSecureID(_)) }); if is_auth_bound_key { notify_gc = Self::mark_unreferenced(tx, key_id) .context("In unbind_auth_bound_keys_for_user.")? || notify_gc; num_unbound += 1; } } log::info!("Deleting {num_unbound} auth-bound keys for user {user_id}"); Ok(()).do_gc(notify_gc) }) .context(ks_err!()) } fn load_key_components( tx: &Transaction, load_bits: KeyEntryLoadBits, key_id: i64, ) -> Result { let metadata = KeyMetaData::load_from_db(key_id, tx).context("In load_key_components.")?; let (has_km_blob, key_blob_info, cert_blob, cert_chain_blob) = Self::load_blob_components(key_id, load_bits, tx).context("In load_key_components.")?; let parameters = Self::load_key_parameters(key_id, tx) .context("In load_key_components: Trying to load key parameters.")?; let km_uuid = Self::get_key_km_uuid(tx, key_id) .context("In load_key_components: Trying to get KM uuid.")?; Ok(KeyEntry { id: key_id, key_blob_info, cert: cert_blob, cert_chain: cert_chain_blob, km_uuid, parameters, metadata, pure_cert: !has_km_blob, }) } /// Returns a list of KeyDescriptors in the selected domain/namespace whose /// aliases are greater than the specified 'start_past_alias'. If no value /// is provided, returns all KeyDescriptors. /// The key descriptors will have the domain, nspace, and alias field set. /// The returned list will be sorted by alias. /// Domain must be APP or SELINUX, the caller must make sure of that. /// Number of returned values is limited to 10,000 (which is empirically roughly /// what will fit in a Binder message). pub fn list_past_alias( &mut self, domain: Domain, namespace: i64, key_type: KeyType, start_past_alias: Option<&str>, ) -> Result> { let _wp = wd::watch("KeystoreDB::list_past_alias"); let query = format!( "SELECT DISTINCT alias FROM persistent.keyentry WHERE domain = ? AND namespace = ? AND alias IS NOT NULL AND state = ? AND key_type = ? {} ORDER BY alias ASC LIMIT 10000;", if start_past_alias.is_some() { " AND alias > ?" } else { "" } ); self.with_transaction(TransactionBehavior::Deferred, |tx| { let mut stmt = tx.prepare(&query).context(ks_err!("Failed to prepare."))?; let mut rows = match start_past_alias { Some(past_alias) => stmt .query(params![ domain.0 as u32, namespace, KeyLifeCycle::Live, key_type, past_alias ]) .context(ks_err!("Failed to query."))?, None => stmt .query(params![domain.0 as u32, namespace, KeyLifeCycle::Live, key_type,]) .context(ks_err!("Failed to query."))?, }; let mut descriptors: Vec = Vec::new(); db_utils::with_rows_extract_all(&mut rows, |row| { descriptors.push(KeyDescriptor { domain, nspace: namespace, alias: Some(row.get(0).context("Trying to extract alias.")?), blob: None, }); Ok(()) }) .context(ks_err!("Failed to extract rows."))?; Ok(descriptors).no_gc() }) } /// Returns a number of KeyDescriptors in the selected domain/namespace. /// Domain must be APP or SELINUX, the caller must make sure of that. pub fn count_keys( &mut self, domain: Domain, namespace: i64, key_type: KeyType, ) -> Result { let _wp = wd::watch("KeystoreDB::countKeys"); let num_keys = self.with_transaction(TransactionBehavior::Deferred, |tx| { tx.query_row( "SELECT COUNT(alias) FROM persistent.keyentry WHERE domain = ? AND namespace = ? AND alias IS NOT NULL AND state = ? AND key_type = ?;", params![domain.0 as u32, namespace, KeyLifeCycle::Live, key_type], |row| row.get(0), ) .context(ks_err!("Failed to count number of keys.")) .no_gc() })?; Ok(num_keys) } /// Adds a grant to the grant table. /// Like `load_key_entry` this function loads the access tuple before /// it uses the callback for a permission check. Upon success, /// it inserts the `grantee_uid`, `key_id`, and `access_vector` into the /// grant table. The new row will have a randomized id, which is used as /// grant id in the namespace field of the resulting KeyDescriptor. pub fn grant( &mut self, key: &KeyDescriptor, caller_uid: u32, grantee_uid: u32, access_vector: KeyPermSet, check_permission: impl Fn(&KeyDescriptor, &KeyPermSet) -> Result<()>, ) -> Result { let _wp = wd::watch("KeystoreDB::grant"); self.with_transaction(Immediate("TX_grant"), |tx| { // Load the key_id and complete the access control tuple. // We ignore the access vector here because grants cannot be granted. // The access vector returned here expresses the permissions the // grantee has if key.domain == Domain::GRANT. But this vector // cannot include the grant permission by design, so there is no way the // subsequent permission check can pass. // We could check key.domain == Domain::GRANT and fail early. // But even if we load the access tuple by grant here, the permission // check denies the attempt to create a grant by grant descriptor. let access = Self::load_access_tuple(tx, key, KeyType::Client, caller_uid).context(ks_err!())?; // Perform access control. It is vital that we return here if the permission // was denied. So do not touch that '?' at the end of the line. // This permission check checks if the caller has the grant permission // for the given key and in addition to all of the permissions // expressed in `access_vector`. check_permission(&access.descriptor, &access_vector) .context(ks_err!("check_permission failed"))?; let grant_id = if let Some(grant_id) = tx .query_row( "SELECT id FROM persistent.grant WHERE keyentryid = ? AND grantee = ?;", params![access.key_id, grantee_uid], |row| row.get(0), ) .optional() .context(ks_err!("Failed get optional existing grant id."))? { tx.execute( "UPDATE persistent.grant SET access_vector = ? WHERE id = ?;", params![i32::from(access_vector), grant_id], ) .context(ks_err!("Failed to update existing grant."))?; grant_id } else { Self::insert_with_retry(|id| { tx.execute( "INSERT INTO persistent.grant (id, grantee, keyentryid, access_vector) VALUES (?, ?, ?, ?);", params![id, grantee_uid, access.key_id, i32::from(access_vector)], ) }) .context(ks_err!())? }; Ok(KeyDescriptor { domain: Domain::GRANT, nspace: grant_id, alias: None, blob: None }) .no_gc() }) } /// This function checks permissions like `grant` and `load_key_entry` /// before removing a grant from the grant table. pub fn ungrant( &mut self, key: &KeyDescriptor, caller_uid: u32, grantee_uid: u32, check_permission: impl Fn(&KeyDescriptor) -> Result<()>, ) -> Result<()> { let _wp = wd::watch("KeystoreDB::ungrant"); self.with_transaction(Immediate("TX_ungrant"), |tx| { // Load the key_id and complete the access control tuple. // We ignore the access vector here because grants cannot be granted. let access = Self::load_access_tuple(tx, key, KeyType::Client, caller_uid).context(ks_err!())?; // Perform access control. We must return here if the permission // was denied. So do not touch the '?' at the end of this line. check_permission(&access.descriptor).context(ks_err!("check_permission failed."))?; tx.execute( "DELETE FROM persistent.grant WHERE keyentryid = ? AND grantee = ?;", params![access.key_id, grantee_uid], ) .context("Failed to delete grant.")?; Ok(()).no_gc() }) } // Generates a random id and passes it to the given function, which will // try to insert it into a database. If that insertion fails, retry; // otherwise return the id. fn insert_with_retry(inserter: impl Fn(i64) -> rusqlite::Result) -> Result { loop { let newid: i64 = match random() { Self::UNASSIGNED_KEY_ID => continue, // UNASSIGNED_KEY_ID cannot be assigned. i => i, }; match inserter(newid) { // If the id already existed, try again. Err(rusqlite::Error::SqliteFailure( libsqlite3_sys::Error { code: libsqlite3_sys::ErrorCode::ConstraintViolation, extended_code: libsqlite3_sys::SQLITE_CONSTRAINT_UNIQUE, }, _, )) => (), Err(e) => { return Err(e).context(ks_err!("failed to insert into database.")); } _ => return Ok(newid), } } } /// Insert or replace the auth token based on (user_id, auth_id, auth_type) pub fn insert_auth_token(&mut self, auth_token: &HardwareAuthToken) { self.perboot .insert_auth_token_entry(AuthTokenEntry::new(auth_token.clone(), BootTime::now())) } /// Find the newest auth token matching the given predicate. pub fn find_auth_token_entry(&self, p: F) -> Option where F: Fn(&AuthTokenEntry) -> bool, { self.perboot.find_auth_token_entry(p) } /// Load descriptor of a key by key id pub fn load_key_descriptor(&mut self, key_id: i64) -> Result> { let _wp = wd::watch("KeystoreDB::load_key_descriptor"); self.with_transaction(TransactionBehavior::Deferred, |tx| { tx.query_row( "SELECT domain, namespace, alias FROM persistent.keyentry WHERE id = ?;", params![key_id], |row| { Ok(KeyDescriptor { domain: Domain(row.get(0)?), nspace: row.get(1)?, alias: row.get(2)?, blob: None, }) }, ) .optional() .context("Trying to load key descriptor") .no_gc() }) .context(ks_err!()) } /// Returns a list of app UIDs that have keys authenticated by the given secure_user_id /// (for the given user_id). /// This is helpful for finding out which apps will have their keys invalidated when /// the user changes biometrics enrollment or removes their LSKF. pub fn get_app_uids_affected_by_sid( &mut self, user_id: i32, secure_user_id: i64, ) -> Result> { let _wp = wd::watch("KeystoreDB::get_app_uids_affected_by_sid"); let ids = self.with_transaction(Immediate("TX_get_app_uids_affected_by_sid"), |tx| { let mut stmt = tx .prepare(&format!( "SELECT id, namespace from persistent.keyentry WHERE key_type = ? AND domain = ? AND cast ( (namespace/{AID_USER_OFFSET}) as int) = ? AND state = ?;", )) .context(concat!( "In get_app_uids_affected_by_sid, ", "failed to prepare the query to find the keys created by apps." ))?; let mut rows = stmt .query(params![KeyType::Client, Domain::APP.0 as u32, user_id, KeyLifeCycle::Live,]) .context(ks_err!("Failed to query the keys created by apps."))?; let mut key_ids_and_app_uids: HashMap = Default::default(); db_utils::with_rows_extract_all(&mut rows, |row| { key_ids_and_app_uids.insert( row.get(0).context("Failed to read key id of a key created by an app.")?, row.get(1).context("Failed to read the app uid")?, ); Ok(()) })?; Ok(key_ids_and_app_uids).no_gc() })?; let mut app_uids_affected_by_sid: HashSet = Default::default(); for (key_id, app_uid) in ids { // Read the key parameters for each key in its own transaction. It is OK to ignore // an error to get the properties of a particular key since it might have been deleted // under our feet after the previous transaction concluded. If the key was deleted // then it is no longer applicable if it was auth-bound or not. if let Ok(is_key_bound_to_sid) = self.with_transaction(Immediate("TX_get_app_uids_affects_by_sid 2"), |tx| { let params = Self::load_key_parameters(key_id, tx) .context("Failed to load key parameters.")?; // Check if the key is bound to this secure user ID. let is_key_bound_to_sid = params.iter().any(|kp| { matches!( kp.key_parameter_value(), KeyParameterValue::UserSecureID(sid) if *sid == secure_user_id ) }); Ok(is_key_bound_to_sid).no_gc() }) { if is_key_bound_to_sid { app_uids_affected_by_sid.insert(app_uid); } } } let app_uids_vec: Vec = app_uids_affected_by_sid.into_iter().collect(); Ok(app_uids_vec) } }