crypto: Add support to display the decimal SAS value.

matrix_sdk_crypto/src/verification/sas.rs

@@ -1,13 +1,15 @@
+use std::mem;
+
 use crate::Device;
 
 use olm_rs::sas::OlmSas;
 
 use matrix_sdk_common::events::{
     key::verification::{
-        accept::AcceptEvent,
+        accept::AcceptEventContent,
-        key::KeyEvent,
+        key::KeyEventContent,
         mac::MacEvent,
-        start::{MSasV1Content, MSasV1ContentOptions, StartEvent, StartEventContent},
+        start::{MSasV1Content, MSasV1ContentOptions, StartEventContent},
         HashAlgorithm, KeyAgreementProtocol, MessageAuthenticationCode, ShortAuthenticationString,
         VerificationMethod,
     },
@@ -30,10 +32,22 @@ struct AcceptedProtocols {
     short_auth_string: Vec<ShortAuthenticationString>,
 }
 
+impl From<AcceptEventContent> for AcceptedProtocols {
+    fn from(content: AcceptEventContent) -> Self {
+        Self {
+            method: content.method,
+            hash: content.hash,
+            key_agreement_protocol: content.key_agreement_protocol,
+            message_auth_code: content.message_authentication_code,
+            short_auth_string: content.short_authentication_string.clone(),
+        }
+    }
+}
+
 struct Sas<S> {
     inner: OlmSas,
     ids: SasIds,
-    verification_flow_id: Uuid,
+    verification_flow_id: String,
     state: S,
 }
 
@@ -45,7 +59,7 @@ impl<S> Sas<S> {
 
 impl Sas<Created> {
     fn new(own_user_id: UserId, own_device_id: &DeviceId, other_device: Device) -> Sas<Created> {
-        let verification_flow_id = Uuid::new_v4();
+        let verification_flow_id = Uuid::new_v4().to_string();
 
         Sas {
             inner: OlmSas::new(),
@@ -54,11 +68,11 @@ impl Sas<Created> {
                 own_device_id: own_device_id.into(),
                 other_device,
             },
-            verification_flow_id,
+            verification_flow_id: verification_flow_id.clone(),
 
             state: Created {
                 protocol_definitions: MSasV1ContentOptions {
-                    transaction_id: verification_flow_id.to_string(),
+                    transaction_id: verification_flow_id,
                     from_device: own_device_id.into(),
                     short_authentication_string: vec![
                         ShortAuthenticationString::Decimal,
@@ -79,7 +93,7 @@ impl Sas<Created> {
         )
     }
 
-    fn into_accepted(self, event: &AcceptEvent) -> Sas<Accepted> {
+    fn into_accepted(self, event: &ToDeviceEvent<AcceptEventContent>) -> Sas<Accepted> {
         let content = &event.content;
 
         Sas {
@@ -88,13 +102,7 @@ impl Sas<Created> {
             verification_flow_id: self.verification_flow_id,
             state: Accepted {
                 commitment: content.commitment.clone(),
-                accepted_protocols: AcceptedProtocols {
+                accepted_protocols: content.clone().into(),
-                    method: content.method,
-                    hash: content.hash,
-                    key_agreement_protocol: content.key_agreement_protocol,
-                    message_auth_code: content.message_authentication_code,
-                    short_auth_string: content.short_authentication_string.clone(),
-                },
             },
         }
     }
@@ -130,7 +138,7 @@ impl Sas<Started> {
                 other_device,
             },
 
-            verification_flow_id: Uuid::new_v4(),
+            verification_flow_id: content.transaction_id.clone(),
 
             state: Started {
                 protocol_definitions: content.clone(),
@@ -138,8 +146,37 @@ impl Sas<Started> {
         }
     }
 
-    fn into_key_received(self, event: &KeyEvent) -> Sas<KeyReceived> {
+    fn get_accept_content(&self) -> AcceptEventContent {
-        todo!()
+        AcceptEventContent {
+            method: VerificationMethod::MSasV1,
+            transaction_id: self.verification_flow_id.to_string(),
+            commitment: "".to_owned(),
+            hash: HashAlgorithm::Sha256,
+            key_agreement_protocol: KeyAgreementProtocol::Curve25519HkdfSha256,
+            message_authentication_code: MessageAuthenticationCode::HkdfHmacSha256,
+            short_authentication_string: self
+                .state
+                .protocol_definitions
+                .short_authentication_string
+                .clone(),
+        }
+    }
+
+    fn into_key_received(mut self, event: &mut ToDeviceEvent<KeyEventContent>) -> Sas<KeyReceived> {
+        let accepted_protocols: AcceptedProtocols = self.get_accept_content().into();
+        self.inner
+            .set_their_public_key(&mem::take(&mut event.content.key))
+            .expect("Can't set public key");
+
+        Sas {
+            inner: self.inner,
+            ids: self.ids,
+            verification_flow_id: self.verification_flow_id,
+            state: KeyReceived {
+                we_started: false,
+                accepted_protocols,
+            },
+        }
     }
 }
 
@@ -149,16 +186,87 @@ struct Accepted {
 }
 
 impl Sas<Accepted> {
-    fn into_key_received(self, event: &KeyEvent) -> Sas<KeyReceived> {
+    fn into_key_received(mut self, event: &mut ToDeviceEvent<KeyEventContent>) -> Sas<KeyReceived> {
-        todo!()
+        self.inner
+            .set_their_public_key(&mem::take(&mut event.content.key))
+            .expect("Can't set public key");
+
+        Sas {
+            inner: self.inner,
+            ids: self.ids,
+            verification_flow_id: self.verification_flow_id,
+            state: KeyReceived {
+                we_started: true,
+                accepted_protocols: self.state.accepted_protocols,
+            },
+        }
+    }
+
+    fn get_key_content(&self) -> KeyEventContent {
+        KeyEventContent {
+            transaction_id: self.verification_flow_id.to_string(),
+            key: self.inner.public_key(),
+        }
     }
 }
 
 struct KeyReceived {
+    we_started: bool,
     accepted_protocols: AcceptedProtocols,
 }
 
 impl Sas<KeyReceived> {
+    fn get_key_content(&self) -> KeyEventContent {
+        KeyEventContent {
+            transaction_id: self.verification_flow_id.to_string(),
+            key: self.inner.public_key(),
+        }
+    }
+
+    fn extra_info(&self) -> String {
+        if self.state.we_started {
+            format!(
+                "MATRIX_KEY_VERIFICATION_SAS{first_user}{first_device}\
+                {second_user}{second_device}{transaction_id}",
+                first_user = self.ids.own_user_id,
+                first_device = self.ids.own_device_id,
+                second_user = self.ids.other_device.user_id(),
+                second_device = self.ids.other_device.device_id(),
+                transaction_id = self.verification_flow_id,
+            )
+        } else {
+            format!(
+                "MATRIX_KEY_VERIFICATION_SAS{first_user}{first_device}\
+                {second_user}{second_device}{transaction_id}",
+                first_user = self.ids.other_device.user_id(),
+                first_device = self.ids.other_device.device_id(),
+                second_user = self.ids.own_user_id,
+                second_device = self.ids.own_device_id,
+                transaction_id = self.verification_flow_id,
+            )
+        }
+    }
+
+    fn get_emoji(&self) -> Vec<(String, String)> {
+        todo!()
+    }
+
+    fn get_decimal(&self) -> (i32, i32, i32) {
+        let bytes: Vec<i32> = self
+            .inner
+            .generate_bytes(&self.extra_info(), 5)
+            .expect("Can't generate bytes")
+            .into_iter()
+            .map(|b| b as i32)
+            .collect();
+
+        let first = (bytes[0] << 5 | bytes[1] >> 3) + 1000;
+        let second = ((bytes[1] & 0x7) << 10 | bytes[2] << 2 | bytes[3] >> 6) + 1000;
+        let third = ((bytes[3] & 0x3F) << 7 | bytes[4] >> 1) + 1000;
+
+        (first, second, third)
+    }
+
     fn into_mac_received(self, event: &MacEvent) -> Sas<MacReceived> {
         todo!()
     }
@@ -199,16 +307,10 @@ mod test {
     use std::convert::TryFrom;
 
     use crate::{Account, Device};
-    use matrix_sdk_common::events::key::verification::{
+    use matrix_sdk_common::events::{EventContent, ToDeviceEvent};
-        accept::AcceptEvent,
-        key::KeyEvent,
-        mac::MacEvent,
-        start::{MSasV1Content, MSasV1ContentOptions, StartEvent, StartEventContent},
-    };
-    use matrix_sdk_common::events::{AnyToDeviceEvent, ToDeviceEvent};
     use matrix_sdk_common::identifiers::{DeviceId, UserId};
 
-    use super::{Created, Sas, Started};
+    use super::{Accepted, Created, Sas, Started};
 
     fn alice_id() -> UserId {
         UserId::try_from("@alice:example.org").unwrap()
@@ -226,18 +328,14 @@ mod test {
         "BOBDEVCIE".into()
     }
 
-    fn wrap_start_event(
+    fn wrap_to_device_event<C: EventContent>(sender: &UserId, content: C) -> ToDeviceEvent<C> {
-        sender: &UserId,
-        content: StartEventContent,
-    ) -> ToDeviceEvent<StartEventContent> {
         ToDeviceEvent {
             sender: sender.clone(),
             content,
         }
     }
 
-    #[tokio::test]
+    async fn get_sas_pair() -> (Sas<Created>, Sas<Started>) {
-    async fn create_sas() {
         let alice = Account::new(&alice_id(), &alice_device_id());
         let alice_device = Device::from_account(&alice).await;
 
@@ -247,9 +345,43 @@ mod test {
         let alice_sas = Sas::<Created>::new(alice_id(), &alice_device_id(), bob_device);
 
         let start_content = alice_sas.get_start_event();
-        let event = wrap_start_event(alice_sas.user_id(), start_content);
+        let event = wrap_to_device_event(alice_sas.user_id(), start_content);
 
         let bob_sas =
             Sas::<Started>::from_start_event(bob.user_id(), bob.device_id(), alice_device, &event);
+
+        (alice_sas, bob_sas)
+    }
+
+    #[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.get_accept_content());
+
+        alice.into_accepted(&event);
+    }
+
+    #[tokio::test]
+    async fn sas_key_share() {
+        let (alice, bob) = get_sas_pair().await;
+
+        let event = wrap_to_device_event(bob.user_id(), bob.get_accept_content());
+
+        let alice: Sas<Accepted> = alice.into_accepted(&event);
+        let mut event = wrap_to_device_event(alice.user_id(), alice.get_key_content());
+
+        let bob = bob.into_key_received(&mut event);
+
+        let mut event = wrap_to_device_event(bob.user_id(), bob.get_key_content());
+
+        let alice = alice.into_key_received(&mut event);
+
+        assert_eq!(alice.get_decimal(), bob.get_decimal());
     }
 }