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crypto: Split out the Sas logic into different files.

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This commit is contained in:
Damir Jelić 2020-07-31 14:54:08 +02:00
parent 108f6d90c9
commit 7ecd4a035f
5 changed files with 1062 additions and 909 deletions
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2
matrix_sdk_crypto/src/verification/machine.rs
View file

@ -23,7 +23,7 @@ use matrix_sdk_common::{
locks::RwLock,
};
use super::{content_to_request, Sas};
use super::sas::{content_to_request, Sas};
use crate::{Account, CryptoStore, CryptoStoreError};
#[derive(Clone, Debug)]

420
matrix_sdk_crypto/src/verification/mod.rs
View file

@ -12,25 +12,6 @@
// See the License for the specific language governing permissions and
// limitations under the License.
use std::collections::BTreeMap;
use std::convert::TryInto;
use olm_rs::sas::OlmSas;
use matrix_sdk_common::{
api::r0::{
keys::{AlgorithmAndDeviceId, KeyAlgorithm},
to_device::{send_event_to_device::Request as ToDeviceRequest, DeviceIdOrAllDevices},
},
events::{
key::verification::mac::MacEventContent, AnyToDeviceEventContent, EventType, ToDeviceEvent,
},
identifiers::{DeviceId, UserId},
uuid::Uuid,
};
use crate::{Account, Device};
#[allow(dead_code)]
mod machine;
#[allow(dead_code)]
@ -39,407 +20,8 @@ mod sas;
pub use machine::VerificationMachine;
pub use sas::Sas;
#[derive(Clone, Debug)]
struct SasIds {
account: Account,
other_device: Device,
}
/// Get a tuple of an emoji and a description of the emoji using a number.
///
/// This is taken directly from the [spec]
///
/// # Panics
///
/// The spec defines 64 unique emojis, this function panics if the index is
/// bigger than 63.
///
/// [spec]: https://matrix.org/docs/spec/client_server/latest#sas-method-emoji
fn emoji_from_index(index: u8) -> (&'static str, &'static str) {
match index {
0 => ("🐶", "Dog"),
1 => ("🐱", "Cat"),
2 => ("🦁", "Lion"),
3 => ("🐎", "Horse"),
4 => ("🦄", "Unicorn"),
5 => ("🐷", "Pig"),
6 => ("🐘", "Elephant"),
7 => ("🐰", "Rabbit"),
8 => ("🐼", "Panda"),
9 => ("🐓", "Rooster"),
10 => ("🐧", "Penguin"),
11 => ("🐢", "Turtle"),
12 => ("🐟", "Fish"),
13 => ("🐙", "Octopus"),
14 => ("🦋", "Butterfly"),
15 => ("🌷", "Flower"),
16 => ("🌳", "Tree"),
17 => ("🌵", "Cactus"),
18 => ("🍄", "Mushroom"),
19 => ("🌏", "Globe"),
20 => ("🌙", "Moon"),
21 => ("☁️", "Cloud"),
22 => ("🔥", "Fire"),
23 => ("🍌", "Banana"),
24 => ("🍎", "Apple"),
25 => ("🍓", "Strawberry"),
26 => ("🌽", "Corn"),
27 => ("🍕", "Pizza"),
28 => ("🎂", "Cake"),
29 => ("❤️", "Heart"),
30 => ("😀", "Smiley"),
31 => ("🤖", "Robot"),
32 => ("🎩", "Hat"),
33 => ("👓", "Glasses"),
34 => ("🔧", "Spanner"),
35 => ("🎅", "Santa"),
36 => ("👍", "Thumbs up"),
37 => ("☂️", "Umbrella"),
38 => ("⌛", "Hourglass"),
39 => ("⏰", "Clock"),
40 => ("🎁", "Gift"),
41 => ("💡", "Light Bulb"),
42 => ("📕", "Book"),
43 => ("✏️", "Pencil"),
44 => ("📎", "Paperclip"),
45 => ("✂️", "Scissors"),
46 => ("🔒", "Lock"),
47 => ("🔑", "Key"),
48 => ("🔨", "Hammer"),
49 => ("☎️", "Telephone"),
50 => ("🏁", "Flag"),
51 => ("🚂", "Train"),
52 => ("🚲", "Bicycle"),
53 => ("✈️", "Airplane"),
54 => ("🚀", "Rocket"),
55 => ("🏆", "Trophy"),
56 => ("⚽", "Ball"),
57 => ("🎸", "Guitar"),
58 => ("🎺", "Trumpet"),
59 => ("🔔", "Bell"),
60 => ("⚓", "Anchor"),
61 => ("🎧", "Headphones"),
62 => ("📁", "Folder"),
63 => ("📌", "Pin"),
_ => panic!("Trying to fetch an emoji outside the allowed range"),
}
}
/// Get the extra info that will be used when we check the MAC of a
/// m.key.verification.key event.
///
/// # Arguments
///
/// * `ids` - The ids that are used for this SAS authentication flow.
///
/// * `flow_id` - The unique id that identifies this SAS verification process.
fn extra_mac_info_receive(ids: &SasIds, flow_id: &str) -> String {
format!(
"MATRIX_KEY_VERIFICATION_MAC{first_user}{first_device}\
{second_user}{second_device}{transaction_id}",
first_user = ids.other_device.user_id(),
first_device = ids.other_device.device_id(),
second_user = ids.account.user_id(),
second_device = ids.account.device_id(),
transaction_id = flow_id,
)
}
/// Get the content for a m.key.verification.mac event.
///
/// Returns a tuple that contains the list of verified devices and the list of
/// verified master keys.
///
/// # Arguments
///
/// * `sas` - The Olm SAS object that can be used to MACs
///
/// * `ids` - The ids that are used for this SAS authentication flow.
///
/// * `flow_id` - The unique id that identifies this SAS verification process.
///
/// * `event` - The m.key.verification.mac event that was sent to us by
/// the other side.
fn receive_mac_event(
sas: &OlmSas,
ids: &SasIds,
flow_id: &str,
event: &ToDeviceEvent<MacEventContent>,
) -> (Vec<Box<DeviceId>>, Vec<String>) {
// TODO check the event and cancel if it isn't ok (sender, transaction id)
let mut verified_devices: Vec<Box<DeviceId>> = Vec::new();
let info = extra_mac_info_receive(&ids, flow_id);
let mut keys = event.content.mac.keys().cloned().collect::<Vec<String>>();
keys.sort();
let keys = sas
.calculate_mac(&keys.join(","), &format!("{}KEY_IDS", &info))
.expect("Can't calculate SAS MAC");
if keys != event.content.keys {
panic!("Keys mac mismatch")
}
for (key_id, key_mac) in &event.content.mac {
let split: Vec<&str> = key_id.splitn(2, ':').collect();
if split.len() != 2 {
continue;
}
let algorithm: KeyAlgorithm = if let Ok(a) = split[0].try_into() {
a
} else {
continue;
};
let id = split[1];
let device_key_id = AlgorithmAndDeviceId(algorithm, id.into());
if let Some(key) = ids.other_device.keys().get(&device_key_id) {
if key_mac
== &sas
.calculate_mac(key, &format!("{}{}", info, key_id))
.expect("Can't calculate SAS MAC")
{
verified_devices.push(ids.other_device.device_id().into());
} else {
// TODO cancel here
}
}
// TODO add an else branch for the master key here
}
(verified_devices, vec![])
}
/// Get the extra info that will be used when we generate a MAC and need to send
/// it out
///
/// # Arguments
///
/// * `ids` - The ids that are used for this SAS authentication flow.
///
/// * `flow_id` - The unique id that identifies this SAS verification process.
fn extra_mac_info_send(ids: &SasIds, flow_id: &str) -> String {
format!(
"MATRIX_KEY_VERIFICATION_MAC{first_user}{first_device}\
{second_user}{second_device}{transaction_id}",
first_user = ids.account.user_id(),
first_device = ids.account.device_id(),
second_user = ids.other_device.user_id(),
second_device = ids.other_device.device_id(),
transaction_id = flow_id,
)
}
/// Get the content for a m.key.verification.mac event.
///
/// # Arguments
///
/// * `sas` - The Olm SAS object that can be used to generate the MAC
///
/// * `ids` - The ids that are used for this SAS authentication flow.
///
/// * `flow_id` - The unique id that identifies this SAS verification process.
///
/// * `we_started` - Flag signaling if the SAS process was started on our side.
///
/// # Panics
///
/// This will panic if the public key of the other side wasn't set.
fn get_mac_content(sas: &OlmSas, ids: &SasIds, flow_id: &str) -> MacEventContent {
let mut mac: BTreeMap<String, String> = BTreeMap::new();
let key_id = AlgorithmAndDeviceId(KeyAlgorithm::Ed25519, ids.account.device_id().into());
let key = ids.account.identity_keys().ed25519();
let info = extra_mac_info_send(ids, flow_id);
mac.insert(
key_id.to_string(),
sas.calculate_mac(key, &format!("{}{}", info, key_id))
.expect("Can't calculate SAS MAC"),
);
// TODO Add the cross signing master key here if we trust/have it.
let mut keys = mac.keys().cloned().collect::<Vec<String>>();
keys.sort();
let keys = sas
.calculate_mac(&keys.join(","), &format!("{}KEY_IDS", &info))
.expect("Can't calculate SAS MAC");
MacEventContent {
transaction_id: flow_id.to_owned(),
keys,
mac,
}
}
/// Get the extra info that will be used when we generate bytes for the short
/// auth string.
///
/// # Arguments
///
/// * `ids` - The ids that are used for this SAS authentication flow.
///
/// * `flow_id` - The unique id that identifies this SAS verification process.
///
/// * `we_started` - Flag signaling if the SAS process was started on our side.
fn extra_info_sas(ids: &SasIds, flow_id: &str, we_started: bool) -> String {
let (first_user, first_device, second_user, second_device) = if we_started {
(
ids.account.user_id(),
ids.account.device_id(),
ids.other_device.user_id(),
ids.other_device.device_id(),
)
} else {
(
ids.other_device.user_id(),
ids.other_device.device_id(),
ids.account.user_id(),
ids.account.device_id(),
)
};
format!(
"MATRIX_KEY_VERIFICATION_SAS{first_user}{first_device}\
{second_user}{second_device}{transaction_id}",
first_user = first_user,
first_device = first_device,
second_user = second_user,
second_device = second_device,
transaction_id = flow_id,
)
}
/// Get the emoji version of the short authentication string.
///
/// Returns a vector of tuples where the first element is the emoji and the
/// second element the English description of the emoji.
///
/// # Arguments
///
/// * `sas` - The Olm SAS object that can be used to generate bytes using the
/// shared secret.
///
/// * `ids` - The ids that are used for this SAS authentication flow.
///
/// * `flow_id` - The unique id that identifies this SAS verification process.
///
/// * `we_started` - Flag signaling if the SAS process was started on our side.
///
/// # Panics
///
/// This will panic if the public key of the other side wasn't set.
fn get_emoji(
sas: &OlmSas,
ids: &SasIds,
flow_id: &str,
we_started: bool,
) -> Vec<(&'static str, &'static str)> {
let bytes: Vec<u64> = sas
.generate_bytes(&extra_info_sas(&ids, &flow_id, we_started), 6)
.expect("Can't generate bytes")
.into_iter()
.map(|b| b as u64)
.collect();
// Join the 6 bytes into one 64 bit unsigned int. This u64 will contain 48
// bits from our 6 bytes.
let mut num: u64 = bytes[0] << 40;
num += bytes[1] << 32;
num += bytes[2] << 24;
num += bytes[3] << 16;
num += bytes[4] << 8;
num += bytes[5];
// Take the top 42 bits of our 48 bits from the u64 and convert each 6 bits
// into a 6 bit number.
let numbers = vec![
((num >> 42) & 63) as u8,
((num >> 36) & 63) as u8,
((num >> 30) & 63) as u8,
((num >> 24) & 63) as u8,
((num >> 18) & 63) as u8,
((num >> 12) & 63) as u8,
((num >> 6) & 63) as u8,
];
// Convert the 6 bit number into a emoji/description tuple.
numbers.into_iter().map(emoji_from_index).collect()
}
/// Get the decimal version of the short authentication string.
///
/// Returns a tuple containing three 4 digit integer numbers that represent
/// the short auth string.
///
/// # Arguments
///
/// * `sas` - The Olm SAS object that can be used to generate bytes using the
/// shared secret.
///
/// * `ids` - The ids that are used for this SAS authentication flow.
///
/// * `flow_id` - The unique id that identifies this SAS verification process.
///
/// * `we_started` - Flag signaling if the SAS process was started on our side.
///
/// # Panics
///
/// This will panic if the public key of the other side wasn't set.
fn get_decimal(sas: &OlmSas, ids: &SasIds, flow_id: &str, we_started: bool) -> (u32, u32, u32) {
let bytes: Vec<u32> = sas
.generate_bytes(&extra_info_sas(&ids, &flow_id, we_started), 5)
.expect("Can't generate bytes")
.into_iter()
.map(|b| b as u32)
.collect();
// This bitwise operation is taken from the [spec]
// [spec]: https://matrix.org/docs/spec/client_server/latest#sas-method-decimal
let first = bytes[0] << 5 | bytes[1] >> 3;
let second = (bytes[1] & 0x7) << 10 | bytes[2] << 2 | bytes[3] >> 6;
let third = (bytes[3] & 0x3F) << 7 | bytes[4] >> 1;
(first + 1000, second + 1000, third + 1000)
}
pub(crate) fn content_to_request(
recipient: &UserId,
recipient_device: &DeviceId,
content: AnyToDeviceEventContent,
) -> ToDeviceRequest {
let mut messages = BTreeMap::new();
let mut user_messages = BTreeMap::new();
user_messages.insert(
DeviceIdOrAllDevices::DeviceId(recipient_device.into()),
serde_json::value::to_raw_value(&content).expect("Can't serialize to-device content"),
);
messages.insert(recipient.clone(), user_messages);
let event_type = match content {
AnyToDeviceEventContent::KeyVerificationAccept(_) => EventType::KeyVerificationAccept,
AnyToDeviceEventContent::KeyVerificationStart(_) => EventType::KeyVerificationStart,
AnyToDeviceEventContent::KeyVerificationKey(_) => EventType::KeyVerificationKey,
AnyToDeviceEventContent::KeyVerificationMac(_) => EventType::KeyVerificationMac,
AnyToDeviceEventContent::KeyVerificationCancel(_) => EventType::KeyVerificationCancel,
_ => unreachable!(),
};
ToDeviceRequest {
txn_id: Uuid::new_v4().to_string(),
event_type,
messages,
}
}
#[cfg(test)]
mod test {
pub(crate) mod test {
use serde_json::Value;
use matrix_sdk_common::{

417
matrix_sdk_crypto/src/verification/sas/helpers.rs Normal file
View file

@ -0,0 +1,417 @@
use std::collections::BTreeMap;
use std::convert::TryInto;
use olm_rs::sas::OlmSas;
use matrix_sdk_common::{
api::r0::{
keys::{AlgorithmAndDeviceId, KeyAlgorithm},
to_device::{send_event_to_device::Request as ToDeviceRequest, DeviceIdOrAllDevices},
},
events::{
key::verification::mac::MacEventContent, AnyToDeviceEventContent, EventType, ToDeviceEvent,
},
identifiers::{DeviceId, UserId},
uuid::Uuid,
};
use crate::{Account, Device};
#[derive(Clone, Debug)]
pub struct SasIds {
pub account: Account,
pub other_device: Device,
}
/// Get a tuple of an emoji and a description of the emoji using a number.
///
/// This is taken directly from the [spec]
///
/// # Panics
///
/// The spec defines 64 unique emojis, this function panics if the index is
/// bigger than 63.
///
/// [spec]: https://matrix.org/docs/spec/client_server/latest#sas-method-emoji
fn emoji_from_index(index: u8) -> (&'static str, &'static str) {
match index {
0 => ("🐶", "Dog"),
1 => ("🐱", "Cat"),
2 => ("🦁", "Lion"),
3 => ("🐎", "Horse"),
4 => ("🦄", "Unicorn"),
5 => ("🐷", "Pig"),
6 => ("🐘", "Elephant"),
7 => ("🐰", "Rabbit"),
8 => ("🐼", "Panda"),
9 => ("🐓", "Rooster"),
10 => ("🐧", "Penguin"),
11 => ("🐢", "Turtle"),
12 => ("🐟", "Fish"),
13 => ("🐙", "Octopus"),
14 => ("🦋", "Butterfly"),
15 => ("🌷", "Flower"),
16 => ("🌳", "Tree"),
17 => ("🌵", "Cactus"),
18 => ("🍄", "Mushroom"),
19 => ("🌏", "Globe"),
20 => ("🌙", "Moon"),
21 => ("☁️", "Cloud"),
22 => ("🔥", "Fire"),
23 => ("🍌", "Banana"),
24 => ("🍎", "Apple"),
25 => ("🍓", "Strawberry"),
26 => ("🌽", "Corn"),
27 => ("🍕", "Pizza"),
28 => ("🎂", "Cake"),
29 => ("❤️", "Heart"),
30 => ("😀", "Smiley"),
31 => ("🤖", "Robot"),
32 => ("🎩", "Hat"),
33 => ("👓", "Glasses"),
34 => ("🔧", "Spanner"),
35 => ("🎅", "Santa"),
36 => ("👍", "Thumbs up"),
37 => ("☂️", "Umbrella"),
38 => ("⌛", "Hourglass"),
39 => ("⏰", "Clock"),
40 => ("🎁", "Gift"),
41 => ("💡", "Light Bulb"),
42 => ("📕", "Book"),
43 => ("✏️", "Pencil"),
44 => ("📎", "Paperclip"),
45 => ("✂️", "Scissors"),
46 => ("🔒", "Lock"),
47 => ("🔑", "Key"),
48 => ("🔨", "Hammer"),
49 => ("☎️", "Telephone"),
50 => ("🏁", "Flag"),
51 => ("🚂", "Train"),
52 => ("🚲", "Bicycle"),
53 => ("✈️", "Airplane"),
54 => ("🚀", "Rocket"),
55 => ("🏆", "Trophy"),
56 => ("⚽", "Ball"),
57 => ("🎸", "Guitar"),
58 => ("🎺", "Trumpet"),
59 => ("🔔", "Bell"),
60 => ("⚓", "Anchor"),
61 => ("🎧", "Headphones"),
62 => ("📁", "Folder"),
63 => ("📌", "Pin"),
_ => panic!("Trying to fetch an emoji outside the allowed range"),
}
}
/// Get the extra info that will be used when we check the MAC of a
/// m.key.verification.key event.
///
/// # Arguments
///
/// * `ids` - The ids that are used for this SAS authentication flow.
///
/// * `flow_id` - The unique id that identifies this SAS verification process.
fn extra_mac_info_receive(ids: &SasIds, flow_id: &str) -> String {
format!(
"MATRIX_KEY_VERIFICATION_MAC{first_user}{first_device}\
{second_user}{second_device}{transaction_id}",
first_user = ids.other_device.user_id(),
first_device = ids.other_device.device_id(),
second_user = ids.account.user_id(),
second_device = ids.account.device_id(),
transaction_id = flow_id,
)
}
/// Get the content for a m.key.verification.mac event.
///
/// Returns a tuple that contains the list of verified devices and the list of
/// verified master keys.
///
/// # Arguments
///
/// * `sas` - The Olm SAS object that can be used to MACs
///
/// * `ids` - The ids that are used for this SAS authentication flow.
///
/// * `flow_id` - The unique id that identifies this SAS verification process.
///
/// * `event` - The m.key.verification.mac event that was sent to us by
/// the other side.
pub fn receive_mac_event(
sas: &OlmSas,
ids: &SasIds,
flow_id: &str,
event: &ToDeviceEvent<MacEventContent>,
) -> (Vec<Box<DeviceId>>, Vec<String>) {
// TODO check the event and cancel if it isn't ok (sender, transaction id)
let mut verified_devices: Vec<Box<DeviceId>> = Vec::new();
let info = extra_mac_info_receive(&ids, flow_id);
let mut keys = event.content.mac.keys().cloned().collect::<Vec<String>>();
keys.sort();
let keys = sas
.calculate_mac(&keys.join(","), &format!("{}KEY_IDS", &info))
.expect("Can't calculate SAS MAC");
if keys != event.content.keys {
panic!("Keys mac mismatch")
}
for (key_id, key_mac) in &event.content.mac {
let split: Vec<&str> = key_id.splitn(2, ':').collect();
if split.len() != 2 {
continue;
}
let algorithm: KeyAlgorithm = if let Ok(a) = split[0].try_into() {
a
} else {
continue;
};
let id = split[1];
let device_key_id = AlgorithmAndDeviceId(algorithm, id.into());
if let Some(key) = ids.other_device.keys().get(&device_key_id) {
if key_mac
== &sas
.calculate_mac(key, &format!("{}{}", info, key_id))
.expect("Can't calculate SAS MAC")
{
verified_devices.push(ids.other_device.device_id().into());
} else {
// TODO cancel here
}
}
// TODO add an else branch for the master key here
}
(verified_devices, vec![])
}
/// Get the extra info that will be used when we generate a MAC and need to send
/// it out
///
/// # Arguments
///
/// * `ids` - The ids that are used for this SAS authentication flow.
///
/// * `flow_id` - The unique id that identifies this SAS verification process.
fn extra_mac_info_send(ids: &SasIds, flow_id: &str) -> String {
format!(
"MATRIX_KEY_VERIFICATION_MAC{first_user}{first_device}\
{second_user}{second_device}{transaction_id}",
first_user = ids.account.user_id(),
first_device = ids.account.device_id(),
second_user = ids.other_device.user_id(),
second_device = ids.other_device.device_id(),
transaction_id = flow_id,
)
}
/// Get the content for a m.key.verification.mac event.
///
/// # Arguments
///
/// * `sas` - The Olm SAS object that can be used to generate the MAC
///
/// * `ids` - The ids that are used for this SAS authentication flow.
///
/// * `flow_id` - The unique id that identifies this SAS verification process.
///
/// * `we_started` - Flag signaling if the SAS process was started on our side.
///
/// # Panics
///
/// This will panic if the public key of the other side wasn't set.
pub fn get_mac_content(sas: &OlmSas, ids: &SasIds, flow_id: &str) -> MacEventContent {
let mut mac: BTreeMap<String, String> = BTreeMap::new();
let key_id = AlgorithmAndDeviceId(KeyAlgorithm::Ed25519, ids.account.device_id().into());
let key = ids.account.identity_keys().ed25519();
let info = extra_mac_info_send(ids, flow_id);
mac.insert(
key_id.to_string(),
sas.calculate_mac(key, &format!("{}{}", info, key_id))
.expect("Can't calculate SAS MAC"),
);
// TODO Add the cross signing master key here if we trust/have it.
let mut keys = mac.keys().cloned().collect::<Vec<String>>();
keys.sort();
let keys = sas
.calculate_mac(&keys.join(","), &format!("{}KEY_IDS", &info))
.expect("Can't calculate SAS MAC");
MacEventContent {
transaction_id: flow_id.to_owned(),
keys,
mac,
}
}
/// Get the extra info that will be used when we generate bytes for the short
/// auth string.
///
/// # Arguments
///
/// * `ids` - The ids that are used for this SAS authentication flow.
///
/// * `flow_id` - The unique id that identifies this SAS verification process.
///
/// * `we_started` - Flag signaling if the SAS process was started on our side.
fn extra_info_sas(ids: &SasIds, flow_id: &str, we_started: bool) -> String {
let (first_user, first_device, second_user, second_device) = if we_started {
(
ids.account.user_id(),
ids.account.device_id(),
ids.other_device.user_id(),
ids.other_device.device_id(),
)
} else {
(
ids.other_device.user_id(),
ids.other_device.device_id(),
ids.account.user_id(),
ids.account.device_id(),
)
};
format!(
"MATRIX_KEY_VERIFICATION_SAS{first_user}{first_device}\
{second_user}{second_device}{transaction_id}",
first_user = first_user,
first_device = first_device,
second_user = second_user,
second_device = second_device,
transaction_id = flow_id,
)
}
/// Get the emoji version of the short authentication string.
///
/// Returns a vector of tuples where the first element is the emoji and the
/// second element the English description of the emoji.
///
/// # Arguments
///
/// * `sas` - The Olm SAS object that can be used to generate bytes using the
/// shared secret.
///
/// * `ids` - The ids that are used for this SAS authentication flow.
///
/// * `flow_id` - The unique id that identifies this SAS verification process.
///
/// * `we_started` - Flag signaling if the SAS process was started on our side.
///
/// # Panics
///
/// This will panic if the public key of the other side wasn't set.
pub fn get_emoji(
sas: &OlmSas,
ids: &SasIds,
flow_id: &str,
we_started: bool,
) -> Vec<(&'static str, &'static str)> {
let bytes: Vec<u64> = sas
.generate_bytes(&extra_info_sas(&ids, &flow_id, we_started), 6)
.expect("Can't generate bytes")
.into_iter()
.map(|b| b as u64)
.collect();
// Join the 6 bytes into one 64 bit unsigned int. This u64 will contain 48
// bits from our 6 bytes.
let mut num: u64 = bytes[0] << 40;
num += bytes[1] << 32;
num += bytes[2] << 24;
num += bytes[3] << 16;
num += bytes[4] << 8;
num += bytes[5];
// Take the top 42 bits of our 48 bits from the u64 and convert each 6 bits
// into a 6 bit number.
let numbers = vec![
((num >> 42) & 63) as u8,
((num >> 36) & 63) as u8,
((num >> 30) & 63) as u8,
((num >> 24) & 63) as u8,
((num >> 18) & 63) as u8,
((num >> 12) & 63) as u8,
((num >> 6) & 63) as u8,
];
// Convert the 6 bit number into a emoji/description tuple.
numbers.into_iter().map(emoji_from_index).collect()
}
/// Get the decimal version of the short authentication string.
///
/// Returns a tuple containing three 4 digit integer numbers that represent
/// the short auth string.
///
/// # Arguments
///
/// * `sas` - The Olm SAS object that can be used to generate bytes using the
/// shared secret.
///
/// * `ids` - The ids that are used for this SAS authentication flow.
///
/// * `flow_id` - The unique id that identifies this SAS verification process.
///
/// * `we_started` - Flag signaling if the SAS process was started on our side.
///
/// # Panics
///
/// This will panic if the public key of the other side wasn't set.
pub fn get_decimal(sas: &OlmSas, ids: &SasIds, flow_id: &str, we_started: bool) -> (u32, u32, u32) {
let bytes: Vec<u32> = sas
.generate_bytes(&extra_info_sas(&ids, &flow_id, we_started), 5)
.expect("Can't generate bytes")
.into_iter()
.map(|b| b as u32)
.collect();
// This bitwise operation is taken from the [spec]
// [spec]: https://matrix.org/docs/spec/client_server/latest#sas-method-decimal
let first = bytes[0] << 5 | bytes[1] >> 3;
let second = (bytes[1] & 0x7) << 10 | bytes[2] << 2 | bytes[3] >> 6;
let third = (bytes[3] & 0x3F) << 7 | bytes[4] >> 1;
(first + 1000, second + 1000, third + 1000)
}
pub fn content_to_request(
recipient: &UserId,
recipient_device: &DeviceId,
content: AnyToDeviceEventContent,
) -> ToDeviceRequest {
let mut messages = BTreeMap::new();
let mut user_messages = BTreeMap::new();
user_messages.insert(
DeviceIdOrAllDevices::DeviceId(recipient_device.into()),
serde_json::value::to_raw_value(&content).expect("Can't serialize to-device content"),
);
messages.insert(recipient.clone(), user_messages);
let event_type = match content {
AnyToDeviceEventContent::KeyVerificationAccept(_) => EventType::KeyVerificationAccept,
AnyToDeviceEventContent::KeyVerificationStart(_) => EventType::KeyVerificationStart,
AnyToDeviceEventContent::KeyVerificationKey(_) => EventType::KeyVerificationKey,
AnyToDeviceEventContent::KeyVerificationMac(_) => EventType::KeyVerificationMac,
AnyToDeviceEventContent::KeyVerificationCancel(_) => EventType::KeyVerificationCancel,
_ => unreachable!(),
};
ToDeviceRequest {
txn_id: Uuid::new_v4().to_string(),
event_type,
messages,
}
}

589
matrix_sdk_crypto/src/verification/sas/mod.rs Normal file
View file

@ -0,0 +1,589 @@
// 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.
mod helpers;
mod sas_state;
use std::sync::{Arc, Mutex};
use matrix_sdk_common::{
api::r0::to_device::send_event_to_device::Request as ToDeviceRequest,
events::{
key::verification::{
accept::AcceptEventContent, cancel::CancelCode, mac::MacEventContent,
start::StartEventContent,
},
AnyToDeviceEvent, AnyToDeviceEventContent, ToDeviceEvent,
},
identifiers::{DeviceId, UserId},
};
use crate::{Account, Device};
pub use helpers::content_to_request;
use sas_state::{
Accepted, Canceled, Confirmed, Created, Done, KeyReceived, MacReceived, SasState, Started,
};
#[derive(Clone, Debug)]
/// Short authentication string object.
pub struct Sas {
inner: Arc<Mutex<InnerSas>>,
account: Account,
other_device: Device,
flow_id: Arc<String>,
}
impl Sas {
/// Get our own user id.
pub fn user_id(&self) -> &UserId {
self.account.user_id()
}
/// Get our own device id.
pub fn device_id(&self) -> &DeviceId {
self.account.device_id()
}
/// Get the user id of the other side.
pub fn other_user_id(&self) -> &UserId {
self.other_device.user_id()
}
/// Get the device id of the other side.
pub fn other_device_id(&self) -> &DeviceId {
self.other_device.device_id()
}
/// Get the unique ID that identifies this SAS verification flow.
pub fn flow_id(&self) -> &str {
&self.flow_id
}
/// Start a new SAS auth flow with the given device.
///
/// # Arguments
///
/// * `account` - Our own account.
///
/// * `other_device` - The other device which we are going to verify.
///
/// Returns the new `Sas` object and a `StartEventContent` that needs to be
/// sent out through the server to the other device.
pub(crate) fn start(account: Account, other_device: Device) -> (Sas, StartEventContent) {
let (inner, content) = InnerSas::start(account.clone(), other_device.clone());
let flow_id = inner.verification_flow_id();
let sas = Sas {
inner: Arc::new(Mutex::new(inner)),
account,
other_device,
flow_id,
};
(sas, content)
}
/// Create a new Sas object from a m.key.verification.start request.
///
/// # Arguments
///
/// * `account` - Our own account.
///
/// * `other_device` - The other device which we are going to verify.
///
/// * `event` - The m.key.verification.start event that was sent to us by
/// the other side.
pub(crate) fn from_start_event(
account: Account,
other_device: Device,
event: &ToDeviceEvent<StartEventContent>,
) -> Result<Sas, AnyToDeviceEventContent> {
let inner = InnerSas::from_start_event(account.clone(), other_device.clone(), event)?;
let flow_id = inner.verification_flow_id();
Ok(Sas {
inner: Arc::new(Mutex::new(inner)),
account,
other_device,
flow_id,
})
}
/// Accept the SAS verification.
///
/// This does nothing if the verification was already accepted, otherwise it
/// returns an `AcceptEventContent` that needs to be sent out.
pub fn accept(&self) -> Option<ToDeviceRequest> {
self.inner.lock().unwrap().accept().map(|c| {
let content = AnyToDeviceEventContent::KeyVerificationAccept(c);
self.content_to_request(content)
})
}
/// Confirm the Sas verification.
///
/// This confirms that the short auth strings match on both sides.
///
/// Does nothing if we're not in a state where we can confirm the short auth
/// string, otherwise returns a `MacEventContent` that needs to be sent to
/// the server.
pub fn confirm(&self) -> Option<ToDeviceRequest> {
let mut guard = self.inner.lock().unwrap();
let sas: InnerSas = (*guard).clone();
let (sas, content) = sas.confirm();
*guard = sas;
content.map(|c| {
let content = AnyToDeviceEventContent::KeyVerificationMac(c);
self.content_to_request(content)
})
}
/// Cancel the verification.
///
/// This cancels the verification with the `CancelCode::User`.
///
/// Returns None if the `Sas` object is already in a canceled state,
/// otherwise it returns a request that needs to be sent out.
pub fn cancel(&self) -> Option<ToDeviceRequest> {
let mut guard = self.inner.lock().unwrap();
let sas: InnerSas = (*guard).clone();
let (sas, content) = sas.cancel();
*guard = sas;
content.map(|c| self.content_to_request(c))
}
/// Are we in a state where we can show the short auth string.
pub fn can_be_presented(&self) -> bool {
self.inner.lock().unwrap().can_be_presented()
}
/// Is the SAS flow done.
pub fn is_done(&self) -> bool {
self.inner.lock().unwrap().is_done()
}
/// Get the emoji version of the short auth string.
///
/// Returns None if we can't yet present the short auth string, otherwise a
/// Vec of tuples with the emoji and description.
pub fn emoji(&self) -> Option<Vec<(&'static str, &'static str)>> {
self.inner.lock().unwrap().emoji()
}
/// Get the decimal version of the short auth string.
///
/// Returns None if we can't yet present the short auth string, otherwise a
/// tuple containing three 4-digit integers that represent the short auth
/// string.
pub fn decimals(&self) -> Option<(u32, u32, u32)> {
self.inner.lock().unwrap().decimals()
}
pub(crate) fn receive_event(
&self,
event: &mut AnyToDeviceEvent,
) -> Option<AnyToDeviceEventContent> {
let mut guard = self.inner.lock().unwrap();
let sas: InnerSas = (*guard).clone();
let (sas, content) = sas.receive_event(event);
*guard = sas;
content
}
pub(crate) fn verified_devices(&self) -> Option<Arc<Vec<Box<DeviceId>>>> {
self.inner.lock().unwrap().verified_devices()
}
pub(crate) fn content_to_request(&self, content: AnyToDeviceEventContent) -> ToDeviceRequest {
content_to_request(self.other_user_id(), self.other_device_id(), content)
}
}
#[derive(Clone, Debug)]
enum InnerSas {
Created(SasState<Created>),
Started(SasState<Started>),
Accepted(SasState<Accepted>),
KeyRecieved(SasState<KeyReceived>),
Confirmed(SasState<Confirmed>),
MacReceived(SasState<MacReceived>),
Done(SasState<Done>),
Canceled(SasState<Canceled>),
}
impl InnerSas {
fn start(account: Account, other_device: Device) -> (InnerSas, StartEventContent) {
let sas = SasState::<Created>::new(account, other_device);
let content = sas.as_content();
(InnerSas::Created(sas), content)
}
fn from_start_event(
account: Account,
other_device: Device,
event: &ToDeviceEvent<StartEventContent>,
) -> Result<InnerSas, AnyToDeviceEventContent> {
match SasState::<Started>::from_start_event(account, other_device, event) {
Ok(s) => Ok(InnerSas::Started(s)),
Err(s) => Err(s.as_content()),
}
}
fn accept(&self) -> Option<AcceptEventContent> {
if let InnerSas::Started(s) = self {
Some(s.as_content())
} else {
None
}
}
fn cancel(self) -> (InnerSas, Option<AnyToDeviceEventContent>) {
let sas = match self {
InnerSas::Created(s) => s.cancel(CancelCode::User),
InnerSas::Started(s) => s.cancel(CancelCode::User),
InnerSas::Accepted(s) => s.cancel(CancelCode::User),
InnerSas::KeyRecieved(s) => s.cancel(CancelCode::User),
InnerSas::MacReceived(s) => s.cancel(CancelCode::User),
_ => return (self, None),
};
let content = sas.as_content();
(InnerSas::Canceled(sas), Some(content))
}
fn confirm(self) -> (InnerSas, Option<MacEventContent>) {
match self {
InnerSas::KeyRecieved(s) => {
let sas = s.confirm();
let content = sas.as_content();
(InnerSas::Confirmed(sas), Some(content))
}
InnerSas::MacReceived(s) => {
let sas = s.confirm();
let content = sas.as_content();
(InnerSas::Done(sas), Some(content))
}
_ => (self, None),
}
}
fn receive_event(
self,
event: &mut AnyToDeviceEvent,
) -> (InnerSas, Option<AnyToDeviceEventContent>) {
match event {
AnyToDeviceEvent::KeyVerificationAccept(e) => {
if let InnerSas::Created(s) = self {
match s.into_accepted(e) {
Ok(s) => {
let content = s.as_content();
(
InnerSas::Accepted(s),
Some(AnyToDeviceEventContent::KeyVerificationKey(content)),
)
}
Err(s) => {
let content = s.as_content();
(InnerSas::Canceled(s), Some(content))
}
}
} else {
(self, None)
}
}
AnyToDeviceEvent::KeyVerificationKey(e) => match self {
InnerSas::Accepted(s) => match s.into_key_received(e) {
Ok(s) => (InnerSas::KeyRecieved(s), None),
Err(s) => {
let content = s.as_content();
(InnerSas::Canceled(s), Some(content))
}
},
InnerSas::Started(s) => match s.into_key_received(e) {
Ok(s) => {
let content = s.as_content();
(
InnerSas::KeyRecieved(s),
Some(AnyToDeviceEventContent::KeyVerificationKey(content)),
)
}
Err(s) => {
let content = s.as_content();
(InnerSas::Canceled(s), Some(content))
}
},
_ => (self, None),
},
AnyToDeviceEvent::KeyVerificationMac(e) => match self {
InnerSas::KeyRecieved(s) => match s.into_mac_received(e) {
Ok(s) => (InnerSas::MacReceived(s), None),
Err(s) => {
let content = s.as_content();
(InnerSas::Canceled(s), Some(content))
}
},
InnerSas::Confirmed(s) => match s.into_done(e) {
Ok(s) => (InnerSas::Done(s), None),
Err(s) => {
let content = s.as_content();
(InnerSas::Canceled(s), Some(content))
}
},
_ => (self, None),
},
_ => (self, None),
}
}
fn can_be_presented(&self) -> bool {
match self {
InnerSas::KeyRecieved(_) => true,
InnerSas::MacReceived(_) => true,
_ => false,
}
}
fn is_done(&self) -> bool {
if let InnerSas::Done(_) = self {
true
} else {
false
}
}
fn verification_flow_id(&self) -> Arc<String> {
match self {
InnerSas::Created(s) => s.verification_flow_id.clone(),
InnerSas::Started(s) => s.verification_flow_id.clone(),
InnerSas::Canceled(s) => s.verification_flow_id.clone(),
InnerSas::Accepted(s) => s.verification_flow_id.clone(),
InnerSas::KeyRecieved(s) => s.verification_flow_id.clone(),
InnerSas::Confirmed(s) => s.verification_flow_id.clone(),
InnerSas::MacReceived(s) => s.verification_flow_id.clone(),
InnerSas::Done(s) => s.verification_flow_id.clone(),
}
}
fn emoji(&self) -> Option<Vec<(&'static str, &'static str)>> {
match self {
InnerSas::KeyRecieved(s) => Some(s.get_emoji()),
InnerSas::MacReceived(s) => Some(s.get_emoji()),
_ => None,
}
}
fn decimals(&self) -> Option<(u32, u32, u32)> {
match self {
InnerSas::KeyRecieved(s) => Some(s.get_decimal()),
InnerSas::MacReceived(s) => Some(s.get_decimal()),
_ => None,
}
}
fn verified_devices(&self) -> Option<Arc<Vec<Box<DeviceId>>>> {
if let InnerSas::Done(s) = self {
Some(s.verified_devices())
} else {
None
}
}
fn verified_master_keys(&self) -> Option<Arc<Vec<String>>> {
if let InnerSas::Done(s) = self {
Some(s.verified_master_keys())
} else {
None
}
}
}
#[cfg(test)]
mod test {
use std::convert::TryFrom;
use matrix_sdk_common::events::{EventContent, ToDeviceEvent};
use matrix_sdk_common::identifiers::{DeviceId, UserId};
use crate::{
verification::test::{get_content_from_request, wrap_any_to_device_content},
Account, Device,
};
use super::{Accepted, Created, Sas, SasState, Started};
fn alice_id() -> UserId {
UserId::try_from("@alice:example.org").unwrap()
}
fn alice_device_id() -> Box<DeviceId> {
"JLAFKJWSCS".into()
}
fn bob_id() -> UserId {
UserId::try_from("@bob:example.org").unwrap()
}
fn bob_device_id() -> Box<DeviceId> {
"BOBDEVCIE".into()
}
fn wrap_to_device_event<C: EventContent>(sender: &UserId, content: C) -> ToDeviceEvent<C> {
ToDeviceEvent {
sender: sender.clone(),
content,
}
}
async fn get_sas_pair() -> (SasState<Created>, SasState<Started>) {
let alice = Account::new(&alice_id(), &alice_device_id());
let alice_device = Device::from_account(&alice).await;
let bob = Account::new(&bob_id(), &bob_device_id());
let bob_device = Device::from_account(&bob).await;
let alice_sas = SasState::<Created>::new(alice.clone(), bob_device);
let start_content = alice_sas.as_content();
let event = wrap_to_device_event(alice_sas.user_id(), start_content);
let bob_sas = SasState::<Started>::from_start_event(bob.clone(), alice_device, &event);
(alice_sas, bob_sas.unwrap())
}
#[tokio::test]
async fn create_sas() {
let (_, _) = get_sas_pair().await;
}
#[tokio::test]
async fn sas_accept() {
let (alice, bob) = get_sas_pair().await;
let event = wrap_to_device_event(bob.user_id(), bob.as_content());
alice.into_accepted(&event).unwrap();
}
#[tokio::test]
async fn sas_key_share() {
let (alice, bob) = get_sas_pair().await;
let event = wrap_to_device_event(bob.user_id(), bob.as_content());
let alice: SasState<Accepted> = alice.into_accepted(&event).unwrap();
let mut event = wrap_to_device_event(alice.user_id(), alice.as_content());
let bob = bob.into_key_received(&mut event).unwrap();
let mut event = wrap_to_device_event(bob.user_id(), bob.as_content());
let alice = alice.into_key_received(&mut event).unwrap();
assert_eq!(alice.get_decimal(), bob.get_decimal());
assert_eq!(alice.get_emoji(), bob.get_emoji());
}
#[tokio::test]
async fn sas_full() {
let (alice, bob) = get_sas_pair().await;
let event = wrap_to_device_event(bob.user_id(), bob.as_content());
let alice: SasState<Accepted> = alice.into_accepted(&event).unwrap();
let mut event = wrap_to_device_event(alice.user_id(), alice.as_content());
let bob = bob.into_key_received(&mut event).unwrap();
let mut event = wrap_to_device_event(bob.user_id(), bob.as_content());
let alice = alice.into_key_received(&mut event).unwrap();
assert_eq!(alice.get_decimal(), bob.get_decimal());
assert_eq!(alice.get_emoji(), bob.get_emoji());
let bob = bob.confirm();
let event = wrap_to_device_event(bob.user_id(), bob.as_content());
let alice = alice.into_mac_received(&event).unwrap();
assert!(!alice.get_emoji().is_empty());
let alice = alice.confirm();
let event = wrap_to_device_event(alice.user_id(), alice.as_content());
let bob = bob.into_done(&event).unwrap();
assert!(bob.verified_devices().contains(&alice.device_id().into()));
assert!(alice.verified_devices().contains(&bob.device_id().into()));
}
#[tokio::test]
async fn sas_wrapper_full() {
let alice = Account::new(&alice_id(), &alice_device_id());
let alice_device = Device::from_account(&alice).await;
let bob = Account::new(&bob_id(), &bob_device_id());
let bob_device = Device::from_account(&bob).await;
let (alice, content) = Sas::start(alice, bob_device);
let event = wrap_to_device_event(alice.user_id(), content);
let bob = Sas::from_start_event(bob, alice_device, &event).unwrap();
let mut event = wrap_any_to_device_content(
bob.user_id(),
get_content_from_request(&bob.accept().unwrap()),
);
let content = alice.receive_event(&mut event);
assert!(!alice.can_be_presented());
assert!(!bob.can_be_presented());
let mut event = wrap_any_to_device_content(alice.user_id(), content.unwrap());
let mut event =
wrap_any_to_device_content(bob.user_id(), bob.receive_event(&mut event).unwrap());
assert!(bob.can_be_presented());
alice.receive_event(&mut event);
assert!(alice.can_be_presented());
assert_eq!(alice.emoji().unwrap(), bob.emoji().unwrap());
assert_eq!(alice.decimals().unwrap(), bob.decimals().unwrap());
let mut event = wrap_any_to_device_content(
alice.user_id(),
get_content_from_request(&alice.confirm().unwrap()),
);
bob.receive_event(&mut event);
let mut event = wrap_any_to_device_content(
bob.user_id(),
get_content_from_request(&bob.confirm().unwrap()),
);
alice.receive_event(&mut event);
assert!(alice
.verified_devices()
.unwrap()
.contains(&bob.device_id().into()));
assert!(bob
.verified_devices()
.unwrap()
.contains(&alice.device_id().into()));
}
}

543
matrix_sdk_crypto/src/verification/sas.rs → matrix_sdk_crypto/src/verification/sas/sas_state.rs
View file

@ -20,7 +20,6 @@ use std::{
use olm_rs::{sas::OlmSas, utility::OlmUtility};
use matrix_sdk_common::{
api::r0::to_device::send_event_to_device::Request as ToDeviceRequest,
events::{
key::verification::{
accept::{
@ -34,401 +33,24 @@ use matrix_sdk_common::{
HashAlgorithm, KeyAgreementProtocol, MessageAuthenticationCode,
ShortAuthenticationString, VerificationMethod,
},
AnyToDeviceEvent, AnyToDeviceEventContent, ToDeviceEvent,
AnyToDeviceEventContent, ToDeviceEvent,
},
identifiers::{DeviceId, UserId},
uuid::Uuid,
};
use super::{
content_to_request, get_decimal, get_emoji, get_mac_content, receive_mac_event, SasIds,
};
use super::helpers::{get_decimal, get_emoji, get_mac_content, receive_mac_event, SasIds};
use crate::{Account, Device};
#[derive(Clone, Debug)]
/// Short authentication string object.
pub struct Sas {
inner: Arc<Mutex<InnerSas>>,
account: Account,
other_device: Device,
flow_id: Arc<String>,
}
impl Sas {
const KEY_AGREEMENT_PROTOCOLS: &'static [KeyAgreementProtocol] =
&[KeyAgreementProtocol::Curve25519HkdfSha256];
const HASHES: &'static [HashAlgorithm] = &[HashAlgorithm::Sha256];
const MACS: &'static [MessageAuthenticationCode] = &[MessageAuthenticationCode::HkdfHmacSha256];
const STRINGS: &'static [ShortAuthenticationString] = &[
ShortAuthenticationString::Decimal,
ShortAuthenticationString::Emoji,
];
/// Get our own user id.
pub fn user_id(&self) -> &UserId {
self.account.user_id()
}
/// Get our own device id.
pub fn device_id(&self) -> &DeviceId {
self.account.device_id()
}
/// Get the user id of the other side.
pub fn other_user_id(&self) -> &UserId {
self.other_device.user_id()
}
/// Get the device id of the other side.
pub fn other_device_id(&self) -> &DeviceId {
self.other_device.device_id()
}
/// Get the unique ID that identifies this SAS verification flow.
pub fn flow_id(&self) -> &str {
&self.flow_id
}
/// Start a new SAS auth flow with the given device.
///
/// # Arguments
///
/// * `account` - Our own account.
///
/// * `other_device` - The other device which we are going to verify.
///
/// Returns the new `Sas` object and a `StartEventContent` that needs to be
/// sent out through the server to the other device.
pub(crate) fn start(account: Account, other_device: Device) -> (Sas, StartEventContent) {
let (inner, content) = InnerSas::start(account.clone(), other_device.clone());
let flow_id = inner.verification_flow_id();
let sas = Sas {
inner: Arc::new(Mutex::new(inner)),
account,
other_device,
flow_id,
};
(sas, content)
}
/// Create a new Sas object from a m.key.verification.start request.
///
/// # Arguments
///
/// * `account` - Our own account.
///
/// * `other_device` - The other device which we are going to verify.
///
/// * `event` - The m.key.verification.start event that was sent to us by
/// the other side.
pub(crate) fn from_start_event(
account: Account,
other_device: Device,
event: &ToDeviceEvent<StartEventContent>,
) -> Result<Sas, AnyToDeviceEventContent> {
let inner = InnerSas::from_start_event(account.clone(), other_device.clone(), event)?;
let flow_id = inner.verification_flow_id();
Ok(Sas {
inner: Arc::new(Mutex::new(inner)),
account,
other_device,
flow_id,
})
}
/// Accept the SAS verification.
///
/// This does nothing if the verification was already accepted, otherwise it
/// returns an `AcceptEventContent` that needs to be sent out.
pub fn accept(&self) -> Option<ToDeviceRequest> {
self.inner.lock().unwrap().accept().map(|c| {
let content = AnyToDeviceEventContent::KeyVerificationAccept(c);
self.content_to_request(content)
})
}
/// Confirm the Sas verification.
///
/// This confirms that the short auth strings match on both sides.
///
/// Does nothing if we're not in a state where we can confirm the short auth
/// string, otherwise returns a `MacEventContent` that needs to be sent to
/// the server.
pub fn confirm(&self) -> Option<ToDeviceRequest> {
let mut guard = self.inner.lock().unwrap();
let sas: InnerSas = (*guard).clone();
let (sas, content) = sas.confirm();
*guard = sas;
content.map(|c| {
let content = AnyToDeviceEventContent::KeyVerificationMac(c);
self.content_to_request(content)
})
}
/// Cancel the verification.
///
/// This cancels the verification with the `CancelCode::User`.
///
/// Returns None if the `Sas` object is already in a canceled state,
/// otherwise it returns a request that needs to be sent out.
pub fn cancel(&self) -> Option<ToDeviceRequest> {
let mut guard = self.inner.lock().unwrap();
let sas: InnerSas = (*guard).clone();
let (sas, content) = sas.cancel();
*guard = sas;
content.map(|c| self.content_to_request(c))
}
/// Are we in a state where we can show the short auth string.
pub fn can_be_presented(&self) -> bool {
self.inner.lock().unwrap().can_be_presented()
}
/// Is the SAS flow done.
pub fn is_done(&self) -> bool {
self.inner.lock().unwrap().is_done()
}
/// Get the emoji version of the short auth string.
///
/// Returns None if we can't yet present the short auth string, otherwise a
/// Vec of tuples with the emoji and description.
pub fn emoji(&self) -> Option<Vec<(&'static str, &'static str)>> {
self.inner.lock().unwrap().emoji()
}
/// Get the decimal version of the short auth string.
///
/// Returns None if we can't yet present the short auth string, otherwise a
/// tuple containing three 4-digit integers that represent the short auth
/// string.
pub fn decimals(&self) -> Option<(u32, u32, u32)> {
self.inner.lock().unwrap().decimals()
}
pub(crate) fn receive_event(
&self,
event: &mut AnyToDeviceEvent,
) -> Option<AnyToDeviceEventContent> {
let mut guard = self.inner.lock().unwrap();
let sas: InnerSas = (*guard).clone();
let (sas, content) = sas.receive_event(event);
*guard = sas;
content
}
pub(crate) fn verified_devices(&self) -> Option<Arc<Vec<Box<DeviceId>>>> {
self.inner.lock().unwrap().verified_devices()
}
pub(crate) fn content_to_request(&self, content: AnyToDeviceEventContent) -> ToDeviceRequest {
content_to_request(self.other_user_id(), self.other_device_id(), content)
}
}
#[derive(Clone, Debug)]
enum InnerSas {
Created(SasState<Created>),
Started(SasState<Started>),
Accepted(SasState<Accepted>),
KeyRecieved(SasState<KeyReceived>),
Confirmed(SasState<Confirmed>),
MacReceived(SasState<MacReceived>),
Done(SasState<Done>),
Canceled(SasState<Canceled>),
}
impl InnerSas {
fn start(account: Account, other_device: Device) -> (InnerSas, StartEventContent) {
let sas = SasState::<Created>::new(account, other_device);
let content = sas.as_content();
(InnerSas::Created(sas), content)
}
fn from_start_event(
account: Account,
other_device: Device,
event: &ToDeviceEvent<StartEventContent>,
) -> Result<InnerSas, AnyToDeviceEventContent> {
match SasState::<Started>::from_start_event(account, other_device, event) {
Ok(s) => Ok(InnerSas::Started(s)),
Err(s) => Err(s.as_content()),
}
}
fn accept(&self) -> Option<AcceptEventContent> {
if let InnerSas::Started(s) = self {
Some(s.as_content())
} else {
None
}
}
fn cancel(self) -> (InnerSas, Option<AnyToDeviceEventContent>) {
let sas = match self {
InnerSas::Created(s) => s.cancel(CancelCode::User),
InnerSas::Started(s) => s.cancel(CancelCode::User),
InnerSas::Accepted(s) => s.cancel(CancelCode::User),
InnerSas::KeyRecieved(s) => s.cancel(CancelCode::User),
InnerSas::MacReceived(s) => s.cancel(CancelCode::User),
_ => return (self, None),
};
let content = sas.as_content();
(InnerSas::Canceled(sas), Some(content))
}
fn confirm(self) -> (InnerSas, Option<MacEventContent>) {
match self {
InnerSas::KeyRecieved(s) => {
let sas = s.confirm();
let content = sas.as_content();
(InnerSas::Confirmed(sas), Some(content))
}
InnerSas::MacReceived(s) => {
let sas = s.confirm();
let content = sas.as_content();
(InnerSas::Done(sas), Some(content))
}
_ => (self, None),
}
}
fn receive_event(
self,
event: &mut AnyToDeviceEvent,
) -> (InnerSas, Option<AnyToDeviceEventContent>) {
match event {
AnyToDeviceEvent::KeyVerificationAccept(e) => {
if let InnerSas::Created(s) = self {
match s.into_accepted(e) {
Ok(s) => {
let content = s.as_content();
(
InnerSas::Accepted(s),
Some(AnyToDeviceEventContent::KeyVerificationKey(content)),
)
}
Err(s) => {
let content = s.as_content();
(InnerSas::Canceled(s), Some(content))
}
}
} else {
(self, None)
}
}
AnyToDeviceEvent::KeyVerificationKey(e) => match self {
InnerSas::Accepted(s) => match s.into_key_received(e) {
Ok(s) => (InnerSas::KeyRecieved(s), None),
Err(s) => {
let content = s.as_content();
(InnerSas::Canceled(s), Some(content))
}
},
InnerSas::Started(s) => match s.into_key_received(e) {
Ok(s) => {
let content = s.as_content();
(
InnerSas::KeyRecieved(s),
Some(AnyToDeviceEventContent::KeyVerificationKey(content)),
)
}
Err(s) => {
let content = s.as_content();
(InnerSas::Canceled(s), Some(content))
}
},
_ => (self, None),
},
AnyToDeviceEvent::KeyVerificationMac(e) => match self {
InnerSas::KeyRecieved(s) => match s.into_mac_received(e) {
Ok(s) => (InnerSas::MacReceived(s), None),
Err(s) => {
let content = s.as_content();
(InnerSas::Canceled(s), Some(content))
}
},
InnerSas::Confirmed(s) => match s.into_done(e) {
Ok(s) => (InnerSas::Done(s), None),
Err(s) => {
let content = s.as_content();
(InnerSas::Canceled(s), Some(content))
}
},
_ => (self, None),
},
_ => (self, None),
}
}
fn can_be_presented(&self) -> bool {
match self {
InnerSas::KeyRecieved(_) => true,
InnerSas::MacReceived(_) => true,
_ => false,
}
}
fn is_done(&self) -> bool {
if let InnerSas::Done(_) = self {
true
} else {
false
}
}
fn verification_flow_id(&self) -> Arc<String> {
match self {
InnerSas::Created(s) => s.verification_flow_id.clone(),
InnerSas::Started(s) => s.verification_flow_id.clone(),
InnerSas::Canceled(s) => s.verification_flow_id.clone(),
InnerSas::Accepted(s) => s.verification_flow_id.clone(),
InnerSas::KeyRecieved(s) => s.verification_flow_id.clone(),
InnerSas::Confirmed(s) => s.verification_flow_id.clone(),
InnerSas::MacReceived(s) => s.verification_flow_id.clone(),
InnerSas::Done(s) => s.verification_flow_id.clone(),
}
}
fn emoji(&self) -> Option<Vec<(&'static str, &'static str)>> {
match self {
InnerSas::KeyRecieved(s) => Some(s.get_emoji()),
InnerSas::MacReceived(s) => Some(s.get_emoji()),
_ => None,
}
}
fn decimals(&self) -> Option<(u32, u32, u32)> {
match self {
InnerSas::KeyRecieved(s) => Some(s.get_decimal()),
InnerSas::MacReceived(s) => Some(s.get_decimal()),
_ => None,
}
}
fn verified_devices(&self) -> Option<Arc<Vec<Box<DeviceId>>>> {
if let InnerSas::Done(s) = self {
Some(s.verified_devices())
} else {
None
}
}
fn verified_master_keys(&self) -> Option<Arc<Vec<String>>> {
if let InnerSas::Done(s) = self {
Some(s.verified_master_keys())
} else {
None
}
}
}
const KEY_AGREEMENT_PROTOCOLS: &'static [KeyAgreementProtocol] =
&[KeyAgreementProtocol::Curve25519HkdfSha256];
const HASHES: &'static [HashAlgorithm] = &[HashAlgorithm::Sha256];
const MACS: &'static [MessageAuthenticationCode] = &[MessageAuthenticationCode::HkdfHmacSha256];
const STRINGS: &'static [ShortAuthenticationString] = &[
ShortAuthenticationString::Decimal,
ShortAuthenticationString::Emoji,
];
/// Struct containing the protocols that were agreed to be used for the SAS
/// flow.
@ -473,7 +95,7 @@ impl Default for AcceptedProtocols {
/// This is the generic struc holding common data between the different states
/// and the specific state.
#[derive(Clone)]
struct SasState<S: Clone> {
pub struct SasState<S: Clone> {
/// The Olm SAS struct.
inner: Arc<Mutex<OlmSas>>,
/// Struct holding the identities that are doing the SAS dance.
@ -482,7 +104,7 @@ struct SasState<S: Clone> {
///
/// This will be the transaction id for to-device events and the relates_to
/// field for in-room events.
verification_flow_id: Arc<String>,
pub verification_flow_id: Arc<String>,
/// The SAS state we're in.
state: Arc<S>,
}
@ -499,13 +121,13 @@ impl<S: Clone + std::fmt::Debug> std::fmt::Debug for SasState<S> {
/// The initial SAS state.
#[derive(Clone, Debug)]
struct Created {
pub struct Created {
protocol_definitions: MSasV1ContentInit,
}
/// The initial SAS state if the other side started the SAS verification.
#[derive(Clone, Debug)]
struct Started {
pub struct Started {
commitment: String,
protocol_definitions: MSasV1Content,
}
@ -513,7 +135,7 @@ struct Started {
/// The SAS state we're going to be in after the other side accepted our
/// verification start event.
#[derive(Clone, Debug)]
struct Accepted {
pub struct Accepted {
accepted_protocols: Arc<AcceptedProtocols>,
json_start_content: String,
commitment: String,
@ -524,7 +146,7 @@ struct Accepted {
///
/// From now on we can show the short auth string to the user.
#[derive(Clone, Debug)]
struct KeyReceived {
pub struct KeyReceived {
we_started: bool,
accepted_protocols: Arc<AcceptedProtocols>,
}
@ -533,7 +155,7 @@ struct KeyReceived {
/// short auth string matches. We still need to receive a MAC event from the
/// other side.
#[derive(Clone, Debug)]
struct Confirmed {
pub struct Confirmed {
accepted_protocols: Arc<AcceptedProtocols>,
}
@ -541,7 +163,7 @@ struct Confirmed {
/// other side. Our own user still needs to confirm that the short auth string
/// matches.
#[derive(Clone, Debug)]
struct MacReceived {
pub struct MacReceived {
we_started: bool,
verified_devices: Arc<Vec<Box<DeviceId>>>,
verified_master_keys: Arc<Vec<String>>,
@ -552,29 +174,29 @@ struct MacReceived {
/// We can now mark the device in our verified devices lits as verified and sign
/// the master keys in the verified devices list.
#[derive(Clone, Debug)]
struct Done {
pub struct Done {
verified_devices: Arc<Vec<Box<DeviceId>>>,
verified_master_keys: Arc<Vec<String>>,
}
#[derive(Clone, Debug)]
struct Canceled {
pub struct Canceled {
cancel_code: CancelCode,
reason: &'static str,
}
impl<S: Clone> SasState<S> {
/// Get our own user id.
fn user_id(&self) -> &UserId {
pub fn user_id(&self) -> &UserId {
&self.ids.account.user_id()
}
/// Get our own device id.
fn device_id(&self) -> &DeviceId {
pub fn device_id(&self) -> &DeviceId {
&self.ids.account.device_id()
}
fn cancel(self, cancel_code: CancelCode) -> SasState<Canceled> {
pub fn cancel(self, cancel_code: CancelCode) -> SasState<Canceled> {
SasState {
inner: self.inner,
ids: self.ids,
@ -602,7 +224,7 @@ impl SasState<Created> {
/// * `account` - Our own account.
///
/// * `other_device` - The other device which we are going to verify.
fn new(account: Account, other_device: Device) -> SasState<Created> {
pub fn new(account: Account, other_device: Device) -> SasState<Created> {
let verification_flow_id = Uuid::new_v4().to_string();
SasState {
@ -615,10 +237,10 @@ impl SasState<Created> {
state: Arc::new(Created {
protocol_definitions: MSasV1ContentInit {
short_authentication_string: Sas::STRINGS.to_vec(),
key_agreement_protocols: Sas::KEY_AGREEMENT_PROTOCOLS.to_vec(),
message_authentication_codes: Sas::MACS.to_vec(),
hashes: Sas::HASHES.to_vec(),
short_authentication_string: STRINGS.to_vec(),
key_agreement_protocols: KEY_AGREEMENT_PROTOCOLS.to_vec(),
message_authentication_codes: MACS.to_vec(),
hashes: HASHES.to_vec(),
},
}),
}
@ -627,7 +249,7 @@ impl SasState<Created> {
/// Get the content for the start event.
///
/// The content needs to be sent to the other device.
fn as_content(&self) -> StartEventContent {
pub fn as_content(&self) -> StartEventContent {
StartEventContent {
transaction_id: self.verification_flow_id.to_string(),
from_device: self.device_id().into(),
@ -645,7 +267,7 @@ impl SasState<Created> {
///
/// * `event` - The m.key.verification.accept event that was sent to us by
/// the other side.
fn into_accepted(
pub fn into_accepted(
self,
event: &ToDeviceEvent<AcceptEventContent>,
) -> Result<SasState<Accepted>, SasState<Canceled>> {
@ -653,9 +275,9 @@ impl SasState<Created> {
.map_err(|c| self.clone().cancel(c))?;
if let AcceptMethod::MSasV1(content) = &event.content.method {
if !Sas::KEY_AGREEMENT_PROTOCOLS.contains(&content.key_agreement_protocol)
|| !Sas::HASHES.contains(&content.hash)
|| !Sas::MACS.contains(&content.message_authentication_code)
if !KEY_AGREEMENT_PROTOCOLS.contains(&content.key_agreement_protocol)
|| !HASHES.contains(&content.hash)
|| !MACS.contains(&content.message_authentication_code)
|| (!content
.short_authentication_string
.contains(&ShortAuthenticationString::Emoji)
@ -699,7 +321,7 @@ impl SasState<Started> {
///
/// * `event` - The m.key.verification.start event that was sent to us by
/// the other side.
fn from_start_event(
pub fn from_start_event(
account: Account,
other_device: Device,
event: &ToDeviceEvent<StartEventContent>,
@ -768,7 +390,7 @@ impl SasState<Started> {
/// This should be sent out automatically if the SAS verification flow has
/// been started because of a
/// m.key.verification.request -> m.key.verification.ready flow.
fn as_content(&self) -> AcceptEventContent {
pub fn as_content(&self) -> AcceptEventContent {
let accepted_protocols = AcceptedProtocols::default();
AcceptEventContent {
@ -798,7 +420,7 @@ impl SasState<Started> {
/// * `event` - The m.key.verification.key event that was sent to us by
/// the other side. The event will be modified so it doesn't contain any key
/// anymore.
fn into_key_received(
pub fn into_key_received(
self,
event: &mut ToDeviceEvent<KeyEventContent>,
) -> Result<SasState<KeyReceived>, SasState<Canceled>> {
@ -834,7 +456,7 @@ impl SasState<Accepted> {
/// * `event` - The m.key.verification.key event that was sent to us by
/// the other side. The event will be modified so it doesn't contain any key
/// anymore.
fn into_key_received(
pub fn into_key_received(
self,
event: &mut ToDeviceEvent<KeyEventContent>,
) -> Result<SasState<KeyReceived>, SasState<Canceled>> {
@ -871,7 +493,7 @@ impl SasState<Accepted> {
/// Get the content for the key event.
///
/// The content needs to be automatically sent to the other side.
fn as_content(&self) -> KeyEventContent {
pub fn as_content(&self) -> KeyEventContent {
KeyEventContent {
transaction_id: self.verification_flow_id.to_string(),
key: self.inner.lock().unwrap().public_key(),
@ -884,7 +506,7 @@ impl SasState<KeyReceived> {
///
/// The content needs to be automatically sent to the other side if and only
/// if we_started is false.
fn as_content(&self) -> KeyEventContent {
pub fn as_content(&self) -> KeyEventContent {
KeyEventContent {
transaction_id: self.verification_flow_id.to_string(),
key: self.inner.lock().unwrap().public_key(),
@ -895,7 +517,7 @@ impl SasState<KeyReceived> {
///
/// Returns a vector of tuples where the first element is the emoji and the
/// second element the English description of the emoji.
fn get_emoji(&self) -> Vec<(&'static str, &'static str)> {
pub fn get_emoji(&self) -> Vec<(&'static str, &'static str)> {
get_emoji(
&self.inner.lock().unwrap(),
&self.ids,
@ -908,7 +530,7 @@ impl SasState<KeyReceived> {
///
/// Returns a tuple containing three 4 digit integer numbers that represent
/// the short auth string.
fn get_decimal(&self) -> (u32, u32, u32) {
pub fn get_decimal(&self) -> (u32, u32, u32) {
get_decimal(
&self.inner.lock().unwrap(),
&self.ids,
@ -924,7 +546,7 @@ impl SasState<KeyReceived> {
///
/// * `event` - The m.key.verification.mac event that was sent to us by
/// the other side.
fn into_mac_received(
pub fn into_mac_received(
self,
event: &ToDeviceEvent<MacEventContent>,
) -> Result<SasState<MacReceived>, SasState<Canceled>> {
@ -954,7 +576,7 @@ impl SasState<KeyReceived> {
///
/// This needs to be done by the user, this will put us in the `Confirmed`
/// state.
fn confirm(self) -> SasState<Confirmed> {
pub fn confirm(self) -> SasState<Confirmed> {
SasState {
inner: self.inner,
verification_flow_id: self.verification_flow_id,
@ -974,7 +596,7 @@ impl SasState<Confirmed> {
///
/// * `event` - The m.key.verification.mac event that was sent to us by
/// the other side.
fn into_done(
pub fn into_done(
self,
event: &ToDeviceEvent<MacEventContent>,
) -> Result<SasState<Done>, SasState<Canceled>> {
@ -1002,7 +624,7 @@ impl SasState<Confirmed> {
/// Get the content for the mac event.
///
/// The content needs to be automatically sent to the other side.
fn as_content(&self) -> MacEventContent {
pub fn as_content(&self) -> MacEventContent {
get_mac_content(
&self.inner.lock().unwrap(),
&self.ids,
@ -1016,7 +638,7 @@ impl SasState<MacReceived> {
///
/// This needs to be done by the user, this will put us in the `Done`
/// state since the other side already confirmed and sent us a MAC event.
fn confirm(self) -> SasState<Done> {
pub fn confirm(self) -> SasState<Done> {
SasState {
inner: self.inner,
verification_flow_id: self.verification_flow_id,
@ -1032,7 +654,7 @@ impl SasState<MacReceived> {
///
/// Returns a vector of tuples where the first element is the emoji and the
/// second element the English description of the emoji.
fn get_emoji(&self) -> Vec<(&'static str, &'static str)> {
pub fn get_emoji(&self) -> Vec<(&'static str, &'static str)> {
get_emoji(
&self.inner.lock().unwrap(),
&self.ids,
@ -1045,7 +667,7 @@ impl SasState<MacReceived> {
///
/// Returns a tuple containing three 4 digit integer numbers that represent
/// the short auth string.
fn get_decimal(&self) -> (u32, u32, u32) {
pub fn get_decimal(&self) -> (u32, u32, u32) {
get_decimal(
&self.inner.lock().unwrap(),
&self.ids,
@ -1060,7 +682,7 @@ impl SasState<Done> {
///
/// The content needs to be automatically sent to the other side if it
/// wasn't already sent.
fn as_content(&self) -> MacEventContent {
pub fn as_content(&self) -> MacEventContent {
get_mac_content(
&self.inner.lock().unwrap(),
&self.ids,
@ -1069,12 +691,12 @@ impl SasState<Done> {
}
/// Get the list of verified devices.
fn verified_devices(&self) -> Arc<Vec<Box<DeviceId>>> {
pub fn verified_devices(&self) -> Arc<Vec<Box<DeviceId>>> {
self.state.verified_devices.clone()
}
/// Get the list of verified master keys.
fn verified_master_keys(&self) -> Arc<Vec<String>> {
pub fn verified_master_keys(&self) -> Arc<Vec<String>> {
self.state.verified_master_keys.clone()
}
}
@ -1108,7 +730,7 @@ impl Canceled {
}
impl SasState<Canceled> {
fn as_content(&self) -> AnyToDeviceEventContent {
pub fn as_content(&self) -> AnyToDeviceEventContent {
AnyToDeviceEventContent::KeyVerificationCancel(CancelEventContent {
transaction_id: self.verification_flow_id.to_string(),
reason: self.state.reason.to_string(),
@ -1121,12 +743,11 @@ impl SasState<Canceled> {
mod test {
use std::convert::TryFrom;
use crate::verification::test::{get_content_from_request, wrap_any_to_device_content};
use crate::{Account, Device};
use matrix_sdk_common::events::{EventContent, ToDeviceEvent};
use matrix_sdk_common::identifiers::{DeviceId, UserId};
use super::{Accepted, Created, Sas, SasState, Started};
use super::{Accepted, Created, SasState, Started};
fn alice_id() -> UserId {
UserId::try_from("@alice:example.org").unwrap()
@ -1233,60 +854,4 @@ mod test {
assert!(bob.verified_devices().contains(&alice.device_id().into()));
assert!(alice.verified_devices().contains(&bob.device_id().into()));
}
#[tokio::test]
async fn sas_wrapper_full() {
let alice = Account::new(&alice_id(), &alice_device_id());
let alice_device = Device::from_account(&alice).await;
let bob = Account::new(&bob_id(), &bob_device_id());
let bob_device = Device::from_account(&bob).await;
let (alice, content) = Sas::start(alice, bob_device);
let event = wrap_to_device_event(alice.user_id(), content);
let bob = Sas::from_start_event(bob, alice_device, &event).unwrap();
let mut event = wrap_any_to_device_content(
bob.user_id(),
get_content_from_request(&bob.accept().unwrap()),
);
let content = alice.receive_event(&mut event);
assert!(!alice.can_be_presented());
assert!(!bob.can_be_presented());
let mut event = wrap_any_to_device_content(alice.user_id(), content.unwrap());
let mut event =
wrap_any_to_device_content(bob.user_id(), bob.receive_event(&mut event).unwrap());
assert!(bob.can_be_presented());
alice.receive_event(&mut event);
assert!(alice.can_be_presented());
assert_eq!(alice.emoji().unwrap(), bob.emoji().unwrap());
assert_eq!(alice.decimals().unwrap(), bob.decimals().unwrap());
let mut event = wrap_any_to_device_content(
alice.user_id(),
get_content_from_request(&alice.confirm().unwrap()),
);
bob.receive_event(&mut event);
let mut event = wrap_any_to_device_content(
bob.user_id(),
get_content_from_request(&bob.confirm().unwrap()),
);
alice.receive_event(&mut event);
assert!(alice
.verified_devices()
.unwrap()
.contains(&bob.device_id().into()));
assert!(bob
.verified_devices()
.unwrap()
.contains(&alice.device_id().into()));
}
}