backup: make validation completion fallible

rust/bridge/shared/src/message_backup.rs

@@ -40,6 +40,7 @@ impl From<Error> for MessageBackupValidationError {
     fn from(value: Error) -> Self {
         match value {
             Error::BackupValidation(e) => Self::String(e.to_string()),
+            Error::BackupCompletion(e) => Self::String(e.to_string()),
             Error::Parse(ParseError::Io(e)) => Self::Io(e),
             e @ Error::NoFrames
             | e @ Error::InvalidProtobuf(_)

rust/message-backup/src/backup.rs

@@ -9,7 +9,7 @@ use std::fmt::Debug;
 use derive_where::derive_where;
 use libsignal_protocol::Aci;
 
-use crate::backup::account_data::{AccountData, AccountDataError};
+pub(crate) use crate::backup::account_data::{AccountData, AccountDataError};
 use crate::backup::call::{AdHocCall, CallError};
 use crate::backup::chat::{ChatData, ChatError, ChatItemError, PinOrder};
 use crate::backup::frame::{ChatId, RecipientId};
@@ -38,6 +38,14 @@ pub struct PartialBackup<M: Method> {
     sticker_packs: HashMap<StickerPackId, StickerPack<M>>,
 }
 
+pub struct CompletedBackup<M: Method> {
+    meta: BackupMeta,
+    account_data: M::Value<AccountData<M>>,
+    recipients: HashMap<RecipientId, RecipientData<M>>,
+    chats: ChatsData<M>,
+    sticker_packs: HashMap<StickerPackId, StickerPack<M>>,
+}
+
 #[derive_where(Default)]
 struct ChatsData<M: Method> {
     items: HashMap<ChatId, ChatData<M>>,
@@ -47,7 +55,7 @@ struct ChatsData<M: Method> {
 #[derive(Debug)]
 pub struct Backup {
     pub meta: BackupMeta,
-    pub account_data: Option<AccountData<Store>>,
+    pub account_data: AccountData<Store>,
     pub recipients: HashMap<RecipientId, RecipientData<Store>>,
     pub chats: HashMap<ChatId, ChatData<Store>>,
     pub sticker_packs: HashMap<StickerPackId, StickerPack<Store>>,
@@ -91,9 +99,39 @@ pub enum Purpose {
     RemoteBackup = 1,
 }
 
-impl From<PartialBackup<Store>> for Backup {
-    fn from(value: PartialBackup<Store>) -> Self {
+#[derive(Debug, displaydoc::Display, thiserror::Error)]
+pub enum CompletionError {
+    /// no AccountData frames found
+    MissingAccountData,
+}
+
+impl<M: Method> TryFrom<PartialBackup<M>> for CompletedBackup<M> {
+    type Error = CompletionError;
+
+    fn try_from(value: PartialBackup<M>) -> Result<Self, Self::Error> {
         let PartialBackup {
+            meta,
+            account_data,
+            recipients,
+            chats,
+            sticker_packs,
+        } = value;
+
+        let account_data = account_data.ok_or(CompletionError::MissingAccountData)?;
+
+        Ok(CompletedBackup {
+            meta,
+            account_data,
+            recipients,
+            chats,
+            sticker_packs,
+        })
+    }
+}
+
+impl From<CompletedBackup<Store>> for Backup {
+    fn from(value: CompletedBackup<Store>) -> Self {
+        let CompletedBackup {
             meta,
             account_data,
             recipients,

rust/message-backup/src/lib.rs

@@ -11,7 +11,8 @@ use futures::AsyncRead;
 use mediasan_common::AsyncSkip;
 use protobuf::Message as _;
 
-use crate::backup::Purpose;
+use crate::backup::method::ValidateOnly;
+use crate::backup::{CompletedBackup, Purpose};
 use crate::frame::{
     HmacMismatchError, ReaderFactory, UnvalidatedHmacReader, VerifyHmac, VerifyHmacError,
 };
@@ -42,6 +43,8 @@ pub enum Error {
     /// {0}
     BackupValidation(#[from] backup::ValidationError),
     /// {0}
+    BackupCompletion(#[from] backup::CompletionError),
+    /// {0}
     Parse(#[from] parse::ParseError),
     /// no frames found
     NoFrames,
@@ -81,27 +84,30 @@ impl std::fmt::Display for FoundUnknownField {
 }
 
 impl<R> ReadResult<R> {
-    fn map<T>(self, f: impl FnOnce(R) -> T) -> ReadResult<T> {
+    fn and_then<T>(self, f: impl FnOnce(R) -> Result<T, Error>) -> ReadResult<T> {
         let Self {
             result,
             found_unknown_fields,
         } = self;
         ReadResult {
             found_unknown_fields,
-            result: result.map(f),
+            result: result.and_then(f),
         }
     }
 }
 
 impl<R: AsyncRead + Unpin + VerifyHmac> BackupReader<R> {
     pub async fn read_all(self) -> ReadResult<backup::Backup> {
-        self.collect_all().await.map(Into::into)
+        self.collect_all()
+            .await
+            .and_then(|r| Ok(CompletedBackup::try_from(r)?.into()))
     }
 
     pub async fn validate_all(self) -> ReadResult<()> {
-        self.collect_all()
-            .await
-            .map(|_: backup::PartialBackup<backup::method::ValidateOnly>| ())
+        self.collect_all().await.and_then(|partial| {
+            let _: CompletedBackup<ValidateOnly> = partial.try_into()?;
+            Ok(())
+        })
     }
 
     pub async fn collect_all<M: backup::method::Method>(

rust/message-backup/tests/res/test-cases/invalid/missing-account-data.jsonproto

@@ -0,0 +1,12 @@
+[
+  {
+    "version": "1",
+    "backupTimeMs": "1705692409729"
+  },
+  {
+    "recipient": {
+      "id": "1",
+      "self": {}
+    }
+  }
+]

rust/message-backup/tests/res/test-cases/invalid/missing-account-data.jsonproto.expected

@@ -0,0 +1 @@
+no AccountData frames found

rust/message-backup/tests/res/test-cases/invalid/multiple-account-data.jsonproto

@@ -0,0 +1,28 @@
+[
+  {
+    "version": "1",
+    "backupTimeMs": "1705692409729"
+  },
+  {
+    "recipient": {
+      "id": "1",
+      "self": {}
+    }
+  },
+  {
+    "account": {
+      "profileKey": "YQKRq+3DQklInaOaMcmlzZnN0m/1hzLiaONX7gB12dg=",
+      "accountSettings": {
+        "phoneNumberSharingMode": "NOBODY"
+      }
+    }
+  },
+  {
+    "account": {
+      "profileKey": "YQKRq+3DQklInaOaMcmlzZnN0m/1hzLiaONX7gB12dg=",
+      "accountSettings": {
+        "phoneNumberSharingMode": "NOBODY"
+      }
+    }
+  }
+]

rust/message-backup/tests/res/test-cases/invalid/multiple-account-data.jsonproto.expected

@@ -0,0 +1 @@
+multiple AccountData frames found

rust/message-backup/tests/res/test-cases/valid-encrypted/new-account.binproto.encrypted.source.jsonproto

@@ -3,6 +3,14 @@
         "backupTimeMs": "1705692409729",
         "version": "1"
     },
+    {
+        "account": {
+            "profileKey": "YQKRq+3DQklInaOaMcmlzZnN0m/1hzLiaONX7gB12dg=",
+            "accountSettings": {
+                "phoneNumberSharingMode": "NOBODY"
+            }
+        }
+    },
     {
         "recipient": {
         "id": "2",