Return proper error in case of invalid UTF-8 in json_body

json_body is used in places that need authentication. In
case an unknown field is set, Ruma doesn't parse the field
and so doesn't give an error on invalid UTF-8. But Conduit
has parsed and on error makes json_body None. Return an
error to the client instead of generating an internal error.

src/client_server/account.rs

@@ -157,15 +157,19 @@ pub async fn register_route(
             }
         // Success!
         } else {
+            if let Some(json) = body.json_body {
                 uiaainfo.session = Some(utils::random_string(SESSION_ID_LENGTH));
                 db.uiaa.create(
                     &UserId::parse_with_server_name("", db.globals.server_name())
                         .expect("we know this is valid"),
                     "".into(),
                     &uiaainfo,
-                &body.json_body.expect("body is json"),
+                    &json,
                 )?;
                 return Err(Error::Uiaa(uiaainfo));
+            } else {
+                return Err(Error::BadRequest(ErrorKind::NotJson, "Not json."));
+            }
         }
     }
 
@@ -526,14 +530,14 @@ pub async fn change_password_route(
         }
     // Success!
     } else {
+        if let Some(json) = body.json_body {
             uiaainfo.session = Some(utils::random_string(SESSION_ID_LENGTH));
-        db.uiaa.create(
-            &sender_user,
-            &sender_device,
-            &uiaainfo,
-            &body.json_body.expect("body is json"),
-        )?;
+            db.uiaa
+                .create(&sender_user, &sender_device, &uiaainfo, &json)?;
             return Err(Error::Uiaa(uiaainfo));
+        } else {
+            return Err(Error::BadRequest(ErrorKind::NotJson, "Not json."));
+        }
     }
 
     db.users
@@ -618,14 +622,14 @@ pub async fn deactivate_route(
         }
     // Success!
     } else {
+        if let Some(json) = body.json_body {
             uiaainfo.session = Some(utils::random_string(SESSION_ID_LENGTH));
-        db.uiaa.create(
-            &sender_user,
-            &sender_device,
-            &uiaainfo,
-            &body.json_body.expect("body is json"),
-        )?;
+            db.uiaa
+                .create(&sender_user, &sender_device, &uiaainfo, &json)?;
             return Err(Error::Uiaa(uiaainfo));
+        } else {
+            return Err(Error::BadRequest(ErrorKind::NotJson, "Not json."));
+        }
     }
 
     // Leave all joined rooms and reject all invitations

src/client_server/device.rs

@@ -116,14 +116,14 @@ pub async fn delete_device_route(
         }
     // Success!
     } else {
+        if let Some(json) = body.json_body {
             uiaainfo.session = Some(utils::random_string(SESSION_ID_LENGTH));
-        db.uiaa.create(
-            &sender_user,
-            &sender_device,
-            &uiaainfo,
-            &body.json_body.expect("body is json"),
-        )?;
+            db.uiaa
+                .create(&sender_user, &sender_device, &uiaainfo, &json)?;
             return Err(Error::Uiaa(uiaainfo));
+        } else {
+            return Err(Error::BadRequest(ErrorKind::NotJson, "Not json."));
+        }
     }
 
     db.users.remove_device(&sender_user, &body.device_id)?;
@@ -170,14 +170,14 @@ pub async fn delete_devices_route(
         }
     // Success!
     } else {
+        if let Some(json) = body.json_body {
             uiaainfo.session = Some(utils::random_string(SESSION_ID_LENGTH));
-        db.uiaa.create(
-            &sender_user,
-            &sender_device,
-            &uiaainfo,
-            &body.json_body.expect("body is json"),
-        )?;
+            db.uiaa
+                .create(&sender_user, &sender_device, &uiaainfo, &json)?;
             return Err(Error::Uiaa(uiaainfo));
+        } else {
+            return Err(Error::BadRequest(ErrorKind::NotJson, "Not json."));
+        }
     }
 
     for device_id in &body.devices {

src/client_server/keys.rs

@@ -145,14 +145,14 @@ pub async fn upload_signing_keys_route(
         }
     // Success!
     } else {
+        if let Some(json) = body.json_body {
             uiaainfo.session = Some(utils::random_string(SESSION_ID_LENGTH));
-        db.uiaa.create(
-            &sender_user,
-            &sender_device,
-            &uiaainfo,
-            &body.json_body.expect("body is json"),
-        )?;
+            db.uiaa
+                .create(&sender_user, &sender_device, &uiaainfo, &json)?;
             return Err(Error::Uiaa(uiaainfo));
+        } else {
+            return Err(Error::BadRequest(ErrorKind::NotJson, "Not json."));
+        }
     }
 
     if let Some(master_key) = &body.master_key {