matrix-rust-sdk/matrix_sdk_crypto/src/identities/user.rs

758 lines
25 KiB
Rust

// Copyright 2020 The Matrix.org Foundation C.I.C.
//
// 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.
use std::{
convert::TryFrom,
sync::{
atomic::{AtomicBool, Ordering},
Arc,
},
};
use serde::{Deserialize, Serialize};
use serde_json::to_value;
use matrix_sdk_common::{
api::r0::keys::CrossSigningKey,
identifiers::{DeviceKeyId, UserId},
};
use crate::{error::SignatureError, verify_json, ReadOnlyDevice};
/// Wrapper for a cross signing key marking it as the master key.
///
/// Master keys are used to sign other cross signing keys, the self signing and
/// user signing keys of an user will be signed by their master key.
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct MasterPubkey(Arc<CrossSigningKey>);
/// Wrapper for a cross signing key marking it as a self signing key.
///
/// Self signing keys are used to sign the user's own devices.
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct SelfSigningPubkey(Arc<CrossSigningKey>);
/// Wrapper for a cross signing key marking it as a user signing key.
///
/// User signing keys are used to sign the master keys of other users.
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct UserSigningPubkey(Arc<CrossSigningKey>);
impl PartialEq for MasterPubkey {
fn eq(&self, other: &MasterPubkey) -> bool {
self.0.user_id == other.0.user_id && self.0.keys == other.0.keys
}
}
impl From<&CrossSigningKey> for MasterPubkey {
fn from(key: &CrossSigningKey) -> Self {
Self(Arc::new(key.clone()))
}
}
impl From<&CrossSigningKey> for SelfSigningPubkey {
fn from(key: &CrossSigningKey) -> Self {
Self(Arc::new(key.clone()))
}
}
impl From<&CrossSigningKey> for UserSigningPubkey {
fn from(key: &CrossSigningKey) -> Self {
Self(Arc::new(key.clone()))
}
}
impl<'a> From<&'a SelfSigningPubkey> for CrossSigningSubKeys<'a> {
fn from(key: &'a SelfSigningPubkey) -> Self {
CrossSigningSubKeys::SelfSigning(key)
}
}
impl<'a> From<&'a UserSigningPubkey> for CrossSigningSubKeys<'a> {
fn from(key: &'a UserSigningPubkey) -> Self {
CrossSigningSubKeys::UserSigning(key)
}
}
/// Enum over the cross signing sub-keys.
enum CrossSigningSubKeys<'a> {
/// The self signing subkey.
SelfSigning(&'a SelfSigningPubkey),
/// The user signing subkey.
UserSigning(&'a UserSigningPubkey),
}
impl<'a> CrossSigningSubKeys<'a> {
/// Get the id of the user that owns this cross signing subkey.
fn user_id(&self) -> &UserId {
match self {
CrossSigningSubKeys::SelfSigning(key) => &key.0.user_id,
CrossSigningSubKeys::UserSigning(key) => &key.0.user_id,
}
}
/// Get the `CrossSigningKey` from an sub-keys enum
fn cross_signing_key(&self) -> &CrossSigningKey {
match self {
CrossSigningSubKeys::SelfSigning(key) => &key.0,
CrossSigningSubKeys::UserSigning(key) => &key.0,
}
}
}
impl MasterPubkey {
/// Get the user id of the master key's owner.
pub fn user_id(&self) -> &UserId {
&self.0.user_id
}
/// Get the master key with the given key id.
///
/// # Arguments
///
/// * `key_id` - The id of the key that should be fetched.
pub fn get_key(&self, key_id: &DeviceKeyId) -> Option<&str> {
self.0.keys.get(key_id.as_str()).map(|k| k.as_str())
}
/// Check if the given cross signing sub-key is signed by the master key.
///
/// # Arguments
///
/// * `subkey` - The subkey that should be checked for a valid signature.
///
/// Returns an empty result if the signature check succeeded, otherwise a
/// SignatureError indicating why the check failed.
fn verify_subkey<'a>(
&self,
subkey: impl Into<CrossSigningSubKeys<'a>>,
) -> Result<(), SignatureError> {
let (key_id, key) = self
.0
.keys
.iter()
.next()
.ok_or(SignatureError::MissingSigningKey)?;
let key_id = DeviceKeyId::try_from(key_id.as_str())?;
// FIXME `KeyUsage is missing PartialEq.
// if self.0.usage.contains(&KeyUsage::Master) {
// return Err(SignatureError::MissingSigningKey);
// }
let subkey: CrossSigningSubKeys = subkey.into();
if &self.0.user_id != subkey.user_id() {
return Err(SignatureError::UserIdMissmatch);
}
verify_json(
&self.0.user_id,
&key_id,
key,
&mut to_value(subkey.cross_signing_key()).map_err(|_| SignatureError::NotAnObject)?,
)
}
}
impl UserSigningPubkey {
/// Get the user id of the user signing key's owner.
pub fn user_id(&self) -> &UserId {
&self.0.user_id
}
/// Check if the given master key is signed by this user signing key.
///
/// # Arguments
///
/// * `master_key` - The master key that should be checked for a valid
/// signature.
///
/// Returns an empty result if the signature check succeeded, otherwise a
/// SignatureError indicating why the check failed.
fn verify_master_key(&self, master_key: &MasterPubkey) -> Result<(), SignatureError> {
let (key_id, key) = self
.0
.keys
.iter()
.next()
.ok_or(SignatureError::MissingSigningKey)?;
// TODO check that the usage is OK.
verify_json(
&self.0.user_id,
&DeviceKeyId::try_from(key_id.as_str())?,
key,
&mut to_value(&*master_key.0).map_err(|_| SignatureError::NotAnObject)?,
)
}
}
impl SelfSigningPubkey {
/// Get the user id of the self signing key's owner.
pub fn user_id(&self) -> &UserId {
&self.0.user_id
}
/// Check if the given device is signed by this self signing key.
///
/// # Arguments
///
/// * `device` - The device that should be checked for a valid signature.
///
/// Returns an empty result if the signature check succeeded, otherwise a
/// SignatureError indicating why the check failed.
fn verify_device(&self, device: &ReadOnlyDevice) -> Result<(), SignatureError> {
let (key_id, key) = self
.0
.keys
.iter()
.next()
.ok_or(SignatureError::MissingSigningKey)?;
// TODO check that the usage is OK.
verify_json(
&self.0.user_id,
&DeviceKeyId::try_from(key_id.as_str())?,
key,
&mut device.as_signature_message(),
)
}
}
/// Enum over the different user identity types we can have.
#[derive(Debug, Clone)]
pub enum UserIdentities {
/// Our own user identity.
Own(OwnUserIdentity),
/// Identities of other users.
Other(UserIdentity),
}
impl UserIdentities {
/// The unique user id of this identity.
pub fn user_id(&self) -> &UserId {
match self {
UserIdentities::Own(i) => i.user_id(),
UserIdentities::Other(i) => i.user_id(),
}
}
/// Get the master key of the identity.
pub fn master_key(&self) -> &MasterPubkey {
match self {
UserIdentities::Own(i) => i.master_key(),
UserIdentities::Other(i) => i.master_key(),
}
}
/// Destructure the enum into an `OwnUserIdentity` if it's of the correct
/// type.
pub fn own(&self) -> Option<&OwnUserIdentity> {
match self {
UserIdentities::Own(i) => Some(i),
_ => None,
}
}
}
impl PartialEq for UserIdentities {
fn eq(&self, other: &UserIdentities) -> bool {
self.user_id() == other.user_id()
}
}
/// Struct representing a cross signing identity of a user.
///
/// This is the user identity of a user that isn't our own. Other users will
/// only contain a master key and a self signing key, meaning that only device
/// signatures can be checked with this identity.
#[derive(Debug, Clone, Deserialize, Serialize)]
pub struct UserIdentity {
user_id: Arc<UserId>,
master_key: MasterPubkey,
self_signing_key: SelfSigningPubkey,
}
impl UserIdentity {
/// Create a new user identity with the given master and self signing key.
///
/// # Arguments
///
/// * `master_key` - The master key of the user identity.
///
/// * `self signing key` - The self signing key of user identity.
///
/// Returns a `SignatureError` if the self signing key fails to be correctly
/// verified by the given master key.
pub fn new(
master_key: MasterPubkey,
self_signing_key: SelfSigningPubkey,
) -> Result<Self, SignatureError> {
master_key.verify_subkey(&self_signing_key)?;
Ok(Self {
user_id: Arc::new(master_key.0.user_id.clone()),
master_key,
self_signing_key,
})
}
/// Get the user id of this identity.
pub fn user_id(&self) -> &UserId {
&self.user_id
}
/// Get the public master key of the identity.
pub fn master_key(&self) -> &MasterPubkey {
&self.master_key
}
/// Update the identity with a new master key and self signing key.
///
/// # Arguments
///
/// * `master_key` - The new master key of the user identity.
///
/// * `self_signing_key` - The new self signing key of user identity.
///
/// Returns a `SignatureError` if we failed to update the identity.
pub fn update(
&mut self,
master_key: MasterPubkey,
self_signing_key: SelfSigningPubkey,
) -> Result<(), SignatureError> {
master_key.verify_subkey(&self_signing_key)?;
self.master_key = master_key;
self.self_signing_key = self_signing_key;
Ok(())
}
/// Check if the given device has been signed by this identity.
///
/// The user_id of the user identity and the user_id of the device need to
/// match for the signature check to succeed as we don't trust users to sign
/// devices of other users.
///
/// # Arguments
///
/// * `device` - The device that should be checked for a valid signature.
///
/// Returns an empty result if the signature check succeeded, otherwise a
/// SignatureError indicating why the check failed.
pub fn is_device_signed(&self, device: &ReadOnlyDevice) -> Result<(), SignatureError> {
if self.user_id() != device.user_id() {
return Err(SignatureError::UserIdMissmatch);
}
self.self_signing_key.verify_device(device)
}
}
/// Struct representing a cross signing identity of our own user.
///
/// This is the user identity of our own user. This user identity will contain a
/// master key, self signing key as well as a user signing key.
///
/// This identity can verify other identities as well as devices belonging to
/// the identity.
#[derive(Debug, Clone)]
pub struct OwnUserIdentity {
user_id: Arc<UserId>,
master_key: MasterPubkey,
self_signing_key: SelfSigningPubkey,
user_signing_key: UserSigningPubkey,
verified: Arc<AtomicBool>,
}
impl OwnUserIdentity {
/// Create a new own user identity with the given master, self signing, and
/// user signing key.
///
/// # Arguments
///
/// * `master_key` - The master key of the user identity.
///
/// * `self_signing_key` - The self signing key of user identity.
///
/// * `user_signing_key` - The user signing key of user identity.
///
/// Returns a `SignatureError` if the self signing key fails to be correctly
/// verified by the given master key.
pub fn new(
master_key: MasterPubkey,
self_signing_key: SelfSigningPubkey,
user_signing_key: UserSigningPubkey,
) -> Result<Self, SignatureError> {
master_key.verify_subkey(&self_signing_key)?;
master_key.verify_subkey(&user_signing_key)?;
Ok(Self {
user_id: Arc::new(master_key.0.user_id.clone()),
master_key,
self_signing_key,
user_signing_key,
verified: Arc::new(AtomicBool::new(false)),
})
}
/// Get the user id of this identity.
pub fn user_id(&self) -> &UserId {
&self.user_id
}
/// Get the public master key of the identity.
pub fn master_key(&self) -> &MasterPubkey {
&self.master_key
}
/// Check if the given identity has been signed by this identity.
///
/// # Arguments
///
/// * `identity` - The identity of another user that we want to check if
/// it's has been signed.
///
/// Returns an empty result if the signature check succeeded, otherwise a
/// SignatureError indicating why the check failed.
pub fn is_identity_signed(&self, identity: &UserIdentity) -> Result<(), SignatureError> {
self.user_signing_key
.verify_master_key(&identity.master_key)
}
/// Check if the given device has been signed by this identity.
///
/// Only devices of our own user should be checked with this method, if a
/// device of a different user is given the signature check will always fail
/// even if a valid signature exists.
///
/// # Arguments
///
/// * `device` - The device that should be checked for a valid signature.
///
/// Returns an empty result if the signature check succeeded, otherwise a
/// SignatureError indicating why the check failed.
pub fn is_device_signed(&self, device: &ReadOnlyDevice) -> Result<(), SignatureError> {
if self.user_id() != device.user_id() {
return Err(SignatureError::UserIdMissmatch);
}
self.self_signing_key.verify_device(device)
}
/// Mark our identity as verified.
pub fn mark_as_verified(&self) {
self.verified.store(true, Ordering::SeqCst)
}
/// Check if our identity is verified.
pub fn is_verified(&self) -> bool {
self.verified.load(Ordering::SeqCst)
}
/// Update the identity with a new master key and self signing key.
///
/// Note: This will reset the verification state if the master keys differ.
///
/// # Arguments
///
/// * `master_key` - The new master key of the user identity.
///
/// * `self_signing_key` - The new self signing key of user identity.
///
/// * `user_signing_key` - The new user signing key of user identity.
///
/// Returns a `SignatureError` if we failed to update the identity.
pub fn update(
&mut self,
master_key: MasterPubkey,
self_signing_key: SelfSigningPubkey,
user_signing_key: UserSigningPubkey,
) -> Result<(), SignatureError> {
master_key.verify_subkey(&self_signing_key)?;
master_key.verify_subkey(&user_signing_key)?;
self.self_signing_key = self_signing_key;
self.user_signing_key = user_signing_key;
if self.master_key != master_key {
self.verified.store(false, Ordering::SeqCst)
}
self.master_key = master_key;
Ok(())
}
}
#[cfg(test)]
mod test {
use serde_json::json;
use std::{convert::TryFrom, sync::Arc};
use matrix_sdk_common::{
api::r0::keys::get_keys::Response as KeyQueryResponse, identifiers::user_id,
};
use crate::{
identities::{Device, ReadOnlyDevice},
machine::test::response_from_file,
olm::Account,
store::memorystore::MemoryStore,
verification::VerificationMachine,
};
use super::{OwnUserIdentity, UserIdentities, UserIdentity};
fn other_key_query() -> KeyQueryResponse {
let data = response_from_file(&json!({
"device_keys": {
"@example2:localhost": {
"SKISMLNIMH": {
"algorithms": ["m.olm.v1.curve25519-aes-sha2", "m.megolm.v1.aes-sha2"],
"device_id": "SKISMLNIMH",
"keys": {
"curve25519:SKISMLNIMH": "qO9xFazIcW8dE0oqHGMojGgJwbBpMOhGnIfJy2pzvmI",
"ed25519:SKISMLNIMH": "y3wV3AoyIGREqrJJVH8DkQtlwHBUxoZ9ApP76kFgXQ8"
},
"signatures": {
"@example2:localhost": {
"ed25519:SKISMLNIMH": "YwbT35rbjKoYFZVU1tQP8MsL06+znVNhNzUMPt6jTEYRBFoC4GDq9hQEJBiFSq37r1jvLMteggVAWw37fs1yBA",
"ed25519:ZtFrSkJ1qB8Jph/ql9Eo/lKpIYCzwvKAKXfkaS4XZNc": "PWuuTE/aTkp1EJQkPHhRx2BxbF+wjMIDFxDRp7JAerlMkDsNFUTfRRusl6vqROPU36cl+yY8oeJTZGFkU6+pBQ"
}
},
"user_id": "@example2:localhost",
"unsigned": {
"device_display_name": "Riot Desktop (Linux)"
}
}
}
},
"failures": {},
"master_keys": {
"@example2:localhost": {
"user_id": "@example2:localhost",
"usage": ["master"],
"keys": {
"ed25519:kC/HmRYw4HNqUp/i4BkwYENrf+hd9tvdB7A1YOf5+Do": "kC/HmRYw4HNqUp/i4BkwYENrf+hd9tvdB7A1YOf5+Do"
},
"signatures": {
"@example2:localhost": {
"ed25519:SKISMLNIMH": "KdUZqzt8VScGNtufuQ8lOf25byYLWIhmUYpPENdmM8nsldexD7vj+Sxoo7PknnTX/BL9h2N7uBq0JuykjunCAw"
}
}
}
},
"self_signing_keys": {
"@example2:localhost": {
"user_id": "@example2:localhost",
"usage": ["self_signing"],
"keys": {
"ed25519:ZtFrSkJ1qB8Jph/ql9Eo/lKpIYCzwvKAKXfkaS4XZNc": "ZtFrSkJ1qB8Jph/ql9Eo/lKpIYCzwvKAKXfkaS4XZNc"
},
"signatures": {
"@example2:localhost": {
"ed25519:kC/HmRYw4HNqUp/i4BkwYENrf+hd9tvdB7A1YOf5+Do": "W/O8BnmiUETPpH02mwYaBgvvgF/atXnusmpSTJZeUSH/vHg66xiZOhveQDG4cwaW8iMa+t9N4h1DWnRoHB4mCQ"
}
}
}
},
"user_signing_keys": {}
}));
KeyQueryResponse::try_from(data).expect("Can't parse the keys upload response")
}
fn own_key_query() -> KeyQueryResponse {
let data = response_from_file(&json!({
"device_keys": {
"@example:localhost": {
"WSKKLTJZCL": {
"algorithms": [
"m.olm.v1.curve25519-aes-sha2",
"m.megolm.v1.aes-sha2"
],
"device_id": "WSKKLTJZCL",
"keys": {
"curve25519:WSKKLTJZCL": "wnip2tbJBJxrFayC88NNJpm61TeSNgYcqBH4T9yEDhU",
"ed25519:WSKKLTJZCL": "lQ+eshkhgKoo+qp9Qgnj3OX5PBoWMU5M9zbuEevwYqE"
},
"signatures": {
"@example:localhost": {
"ed25519:WSKKLTJZCL": "SKpIUnq7QK0xleav0PrIQyKjVm+TgZr7Yi8cKjLeZDtkgyToE2d4/e3Aj79dqOlLB92jFVE4d1cM/Ry04wFwCA",
"ed25519:0C8lCBxrvrv/O7BQfsKnkYogHZX3zAgw3RfJuyiq210": "9UGu1iC5YhFCdELGfB29YaV+QE0t/X5UDSsPf4QcdZyXIwyp9zBbHX2lh9vWudNQ+akZpaq7ZRaaM+4TCnw/Ag"
}
},
"user_id": "@example:localhost",
"unsigned": {
"device_display_name": "Cross signing capable"
}
},
"LVWOVGOXME": {
"algorithms": [
"m.olm.v1.curve25519-aes-sha2",
"m.megolm.v1.aes-sha2"
],
"device_id": "LVWOVGOXME",
"keys": {
"curve25519:LVWOVGOXME": "KMfWKUhnDW1D11hNzATs/Ax1FQRsJxKCWzq0NyGtIiI",
"ed25519:LVWOVGOXME": "k+NC3L7CBD6fBClcHBrKLOkqCyGNSKhWXiH5Q2STRnA"
},
"signatures": {
"@example:localhost": {
"ed25519:LVWOVGOXME": "39Ir5Bttpc5+bQwzLj7rkjm5E5/cp/JTbMJ/t0enj6J5w9MXVBFOUqqM2hpaRaRwILMMpwYbJ8IOGjl0Y/MGAw"
}
},
"user_id": "@example:localhost",
"unsigned": {
"device_display_name": "Non-cross signing"
}
}
}
},
"failures": {},
"master_keys": {
"@example:localhost": {
"user_id": "@example:localhost",
"usage": [
"master"
],
"keys": {
"ed25519:rJ2TAGkEOP6dX41Ksll6cl8K3J48l8s/59zaXyvl2p0": "rJ2TAGkEOP6dX41Ksll6cl8K3J48l8s/59zaXyvl2p0"
},
"signatures": {
"@example:localhost": {
"ed25519:WSKKLTJZCL": "ZzJp1wtmRdykXAUEItEjNiFlBrxx8L6/Vaen9am8AuGwlxxJtOkuY4m+4MPLvDPOgavKHLsrRuNLAfCeakMlCQ"
}
}
}
},
"self_signing_keys": {
"@example:localhost": {
"user_id": "@example:localhost",
"usage": [
"self_signing"
],
"keys": {
"ed25519:0C8lCBxrvrv/O7BQfsKnkYogHZX3zAgw3RfJuyiq210": "0C8lCBxrvrv/O7BQfsKnkYogHZX3zAgw3RfJuyiq210"
},
"signatures": {
"@example:localhost": {
"ed25519:rJ2TAGkEOP6dX41Ksll6cl8K3J48l8s/59zaXyvl2p0": "AC7oDUW4rUhtInwb4lAoBJ0wAuu4a5k+8e34B5+NKsDB8HXRwgVwUWN/MRWc/sJgtSbVlhzqS9THEmQQ1C51Bw"
}
}
}
},
"user_signing_keys": {
"@example:localhost": {
"user_id": "@example:localhost",
"usage": [
"user_signing"
],
"keys": {
"ed25519:DU9z4gBFKFKCk7a13sW9wjT0Iyg7Hqv5f0BPM7DEhPo": "DU9z4gBFKFKCk7a13sW9wjT0Iyg7Hqv5f0BPM7DEhPo"
},
"signatures": {
"@example:localhost": {
"ed25519:rJ2TAGkEOP6dX41Ksll6cl8K3J48l8s/59zaXyvl2p0": "C4L2sx9frGqj8w41KyynHGqwUbbwBYRZpYCB+6QWnvQFA5Oi/1PJj8w5anwzEsoO0TWmLYmf7FXuAGewanOWDg"
}
}
}
}
}));
KeyQueryResponse::try_from(data).expect("Can't parse the keys upload response")
}
fn device(response: &KeyQueryResponse) -> (ReadOnlyDevice, ReadOnlyDevice) {
let mut devices = response.device_keys.values().next().unwrap().values();
let first = ReadOnlyDevice::try_from(devices.next().unwrap()).unwrap();
let second = ReadOnlyDevice::try_from(devices.next().unwrap()).unwrap();
(first, second)
}
fn own_identity(response: &KeyQueryResponse) -> OwnUserIdentity {
let user_id = user_id!("@example:localhost");
let master_key = response.master_keys.get(&user_id).unwrap();
let user_signing = response.user_signing_keys.get(&user_id).unwrap();
let self_signing = response.self_signing_keys.get(&user_id).unwrap();
OwnUserIdentity::new(master_key.into(), self_signing.into(), user_signing.into()).unwrap()
}
#[test]
fn own_identity_create() {
let user_id = user_id!("@example:localhost");
let response = own_key_query();
let master_key = response.master_keys.get(&user_id).unwrap();
let user_signing = response.user_signing_keys.get(&user_id).unwrap();
let self_signing = response.self_signing_keys.get(&user_id).unwrap();
OwnUserIdentity::new(master_key.into(), self_signing.into(), user_signing.into()).unwrap();
}
#[test]
fn other_identity_create() {
let user_id = user_id!("@example2:localhost");
let response = other_key_query();
let master_key = response.master_keys.get(&user_id).unwrap();
let self_signing = response.self_signing_keys.get(&user_id).unwrap();
UserIdentity::new(master_key.into(), self_signing.into()).unwrap();
}
#[test]
fn own_identity_check_signatures() {
let response = own_key_query();
let identity = own_identity(&response);
let (first, second) = device(&response);
assert!(identity.is_device_signed(&first).is_err());
assert!(identity.is_device_signed(&second).is_ok());
let verification_machine = VerificationMachine::new(
Account::new(second.user_id(), second.device_id()),
Arc::new(Box::new(MemoryStore::new())),
);
let first = Device {
inner: first,
verification_machine: verification_machine.clone(),
own_identity: Some(identity.clone()),
device_owner_identity: Some(UserIdentities::Own(identity.clone())),
};
let second = Device {
inner: second,
verification_machine,
own_identity: Some(identity.clone()),
device_owner_identity: Some(UserIdentities::Own(identity.clone())),
};
assert!(!second.trust_state());
assert!(!second.is_trusted());
assert!(!first.trust_state());
assert!(!first.is_trusted());
identity.mark_as_verified();
assert!(second.trust_state());
assert!(!first.trust_state());
}
}