From d39e3141fcc5f3d8c46d7dcf3b83a842dc49c53d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Damir=20Jeli=C4=87?= <poljar@termina.org.uk>
Date: Tue, 22 Dec 2020 14:12:57 +0100
Subject: [PATCH] crypto: Use CanonicalJsonValue for all the signature
 calculations.

---
 matrix_sdk_crypto/src/olm/account.rs            | 12 +++++++-----
 matrix_sdk_crypto/src/olm/signing/mod.rs        |  2 +-
 matrix_sdk_crypto/src/olm/signing/pk_signing.rs |  8 +++++---
 3 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/matrix_sdk_crypto/src/olm/account.rs b/matrix_sdk_crypto/src/olm/account.rs
index 9b6551bd..c619ffeb 100644
--- a/matrix_sdk_crypto/src/olm/account.rs
+++ b/matrix_sdk_crypto/src/olm/account.rs
@@ -43,7 +43,7 @@ use matrix_sdk_common::{
     instant::Instant,
     js_int::UInt,
     locks::Mutex,
-    Raw,
+    CanonicalJsonValue, Raw,
 };
 use olm_rs::{
     account::{IdentityKeys, OlmAccount, OneTimeKeys},
@@ -743,7 +743,7 @@ impl ReadOnlyAccount {
             .or_insert_with(BTreeMap::new)
             .insert(
                 DeviceKeyId::from_parts(DeviceKeyAlgorithm::Ed25519, &self.device_id),
-                self.sign_json(&json_device_keys).await,
+                self.sign_json(json_device_keys).await,
             );
 
         device_keys
@@ -770,8 +770,10 @@ impl ReadOnlyAccount {
     /// # Panic
     ///
     /// Panics if the json value can't be serialized.
-    pub async fn sign_json(&self, json: &Value) -> String {
-        self.sign(&json.to_string()).await
+    pub async fn sign_json(&self, json: Value) -> String {
+        let canonical_json: CanonicalJsonValue =
+            json.try_into().expect("Can't canonicalize the json value");
+        self.sign(&canonical_json.to_string()).await
     }
 
     pub(crate) async fn signed_one_time_keys_helper(
@@ -785,7 +787,7 @@ impl ReadOnlyAccount {
                 "key": key,
             });
 
-            let signature = self.sign_json(&key_json).await;
+            let signature = self.sign_json(key_json).await;
 
             let mut signature_map = BTreeMap::new();
 
diff --git a/matrix_sdk_crypto/src/olm/signing/mod.rs b/matrix_sdk_crypto/src/olm/signing/mod.rs
index 0e73f73e..1208edf1 100644
--- a/matrix_sdk_crypto/src/olm/signing/mod.rs
+++ b/matrix_sdk_crypto/src/olm/signing/mod.rs
@@ -214,7 +214,7 @@ impl PrivateCrossSigningIdentity {
             master.cross_signing_key(account.user_id().to_owned(), KeyUsage::Master);
         let signature = account
             .sign_json(
-                &serde_json::to_value(&public_key)
+                serde_json::to_value(&public_key)
                     .expect("Can't convert own public master key to json"),
             )
             .await;
diff --git a/matrix_sdk_crypto/src/olm/signing/pk_signing.rs b/matrix_sdk_crypto/src/olm/signing/pk_signing.rs
index 661c7a61..b78d11e1 100644
--- a/matrix_sdk_crypto/src/olm/signing/pk_signing.rs
+++ b/matrix_sdk_crypto/src/olm/signing/pk_signing.rs
@@ -23,7 +23,7 @@ use matrix_sdk_common::{
 };
 use serde::{Deserialize, Serialize};
 use serde_json::{json, Error as JsonError, Value};
-use std::{collections::BTreeMap, sync::Arc};
+use std::{collections::BTreeMap, convert::TryInto, sync::Arc};
 use thiserror::Error;
 use zeroize::Zeroizing;
 
@@ -36,6 +36,7 @@ use matrix_sdk_common::{
     api::r0::keys::{CrossSigningKey, KeyUsage},
     identifiers::UserId,
     locks::Mutex,
+    CanonicalJsonValue,
 };
 
 use crate::{
@@ -404,8 +405,9 @@ impl Signing {
     pub async fn sign_json(&self, mut json: Value) -> Result<Signature, SignatureError> {
         let json_object = json.as_object_mut().ok_or(SignatureError::NotAnObject)?;
         let _ = json_object.remove("signatures");
-        let canonical_json = serde_json::to_string(json_object)?;
-        Ok(self.sign(&canonical_json).await)
+        let canonical_json: CanonicalJsonValue =
+            json.try_into().expect("Can't canonicalize the json value");
+        Ok(self.sign(&canonical_json.to_string()).await)
     }
 
     pub async fn sign(&self, message: &str) -> Signature {