From 2a194224f6adb4f8f1d269ee624e234695f7e3e2 Mon Sep 17 00:00:00 2001
From: Florian Duros <florian.duros@ormaz.fr>
Date: Tue, 12 Nov 2024 11:25:59 +0100
Subject: [PATCH 1/2] Add `CryptoApi.getBackupInfo`

---
 spec/unit/crypto/backup.spec.ts           |  8 ++++++++
 spec/unit/rust-crypto/rust-crypto.spec.ts | 14 ++++++++++++++
 src/client.ts                             |  2 +-
 src/crypto-api/index.ts                   |  8 ++++++++
 src/crypto/index.ts                       |  7 +++++++
 src/rust-crypto/rust-crypto.ts            |  7 +++++++
 6 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/spec/unit/crypto/backup.spec.ts b/spec/unit/crypto/backup.spec.ts
index 2d655a9011..28bb0d4c44 100644
--- a/spec/unit/crypto/backup.spec.ts
+++ b/spec/unit/crypto/backup.spec.ts
@@ -780,4 +780,12 @@ describe("MegolmBackup", function () {
             client.stopClient();
         });
     });
+
+    describe("getKeyBackupInfo", () => {
+        it("should return throw an `Not implemented`", async () => {
+            const client = makeTestClient(cryptoStore);
+            await client.initCrypto();
+            await expect(client.getCrypto()?.getKeyBackupInfo()).rejects.toThrow("Not implemented");
+        });
+    });
 });
diff --git a/spec/unit/rust-crypto/rust-crypto.spec.ts b/spec/unit/rust-crypto/rust-crypto.spec.ts
index 117112dd09..8fedadd0d4 100644
--- a/spec/unit/rust-crypto/rust-crypto.spec.ts
+++ b/spec/unit/rust-crypto/rust-crypto.spec.ts
@@ -1526,6 +1526,20 @@ describe("RustCrypto", () => {
                 failures: 1,
             });
         });
+
+        describe("getKeyBackupInfo", () => {
+            it("should return the current key backup info", async () => {
+                fetchMock.get("path:/_matrix/client/v3/room_keys/version", testData.SIGNED_BACKUP_DATA);
+
+                const rustCrypto = await makeTestRustCrypto(makeMatrixHttpApi());
+                await expect(rustCrypto.getKeyBackupInfo()).resolves.toStrictEqual(testData.SIGNED_BACKUP_DATA);
+            });
+
+            it("should return null if not available", async () => {
+                const rustCrypto = await makeTestRustCrypto(makeMatrixHttpApi());
+                await expect(rustCrypto.getKeyBackupInfo()).resolves.toBeNull();
+            });
+        });
     });
 
     describe("device dehydration", () => {
diff --git a/src/client.ts b/src/client.ts
index 6337392bad..999517a107 100644
--- a/src/client.ts
+++ b/src/client.ts
@@ -3352,7 +3352,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
      *
      * @returns Information object from API, or null if no backup is present on the server.
      *
-     * @deprecated Prefer {@link CryptoApi.getActiveSessionBackupVersion}.
+     * @deprecated Prefer {@link CryptoApi.getKeyBackupInfo}.
      */
     public async getKeyBackupVersion(): Promise<IKeyBackupInfo | null> {
         let res: IKeyBackupInfo;
diff --git a/src/crypto-api/index.ts b/src/crypto-api/index.ts
index 1713bf1a8b..7726ac2450 100644
--- a/src/crypto-api/index.ts
+++ b/src/crypto-api/index.ts
@@ -516,6 +516,14 @@ export interface CryptoApi {
      */
     isKeyBackupTrusted(info: KeyBackupInfo): Promise<BackupTrustInfo>;
 
+    /**
+     * Get information about the current key backup.
+     * Return null if there is no backup.
+     *
+     * @returns the key backup information
+     */
+    getKeyBackupInfo(): Promise<KeyBackupInfo | null>;
+
     /**
      * Force a re-check of the key backup and enable/disable it as appropriate.
      *
diff --git a/src/crypto/index.ts b/src/crypto/index.ts
index 2e3bef6eec..d562cc30d0 100644
--- a/src/crypto/index.ts
+++ b/src/crypto/index.ts
@@ -1318,6 +1318,13 @@ export class Crypto extends TypedEventEmitter<CryptoEvent, CryptoEventHandlerMap
         return null;
     }
 
+    /**
+     * Implementation of {@link Crypto.CryptoApi#getKeyBackupInfo}.
+     */
+    public async getKeyBackupInfo(): Promise<KeyBackupInfo | null> {
+        throw new Error("Not implemented");
+    }
+
     /**
      * Determine if a key backup can be trusted.
      *
diff --git a/src/rust-crypto/rust-crypto.ts b/src/rust-crypto/rust-crypto.ts
index c2c9b8304f..5b3c760573 100644
--- a/src/rust-crypto/rust-crypto.ts
+++ b/src/rust-crypto/rust-crypto.ts
@@ -1211,6 +1211,13 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, CryptoEventH
         return await this.backupManager.getActiveBackupVersion();
     }
 
+    /**
+     * Implementation of {@link CryptoApi#getKeyBackupInfo}.
+     */
+    public async getKeyBackupInfo(): Promise<KeyBackupInfo | null> {
+        return (await this.backupManager.getServerBackupInfo()) || null;
+    }
+
     /**
      * Determine if a key backup can be trusted.
      *

From ccc07bb44d2c7e4b6860301573d6e96de7a0a33e Mon Sep 17 00:00:00 2001
From: Florian Duros <florian.duros@ormaz.fr>
Date: Wed, 13 Nov 2024 14:24:51 +0100
Subject: [PATCH 2/2] improve doc

---
 src/crypto-api/index.ts | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/crypto-api/index.ts b/src/crypto-api/index.ts
index 8461686964..89ece07acb 100644
--- a/src/crypto-api/index.ts
+++ b/src/crypto-api/index.ts
@@ -535,7 +535,11 @@ export interface CryptoApi {
     isKeyBackupTrusted(info: KeyBackupInfo): Promise<BackupTrustInfo>;
 
     /**
-     * Get information about the current key backup.
+     * Return the details of the latest backup on the server, when we last checked.
+     *
+     * This normally returns a cached value, but if we haven't yet made a request to the server, it will fire one off.
+     * It will always return the details of the active backup if key backup is enabled.
+     *
      * Return null if there is no backup.
      *
      * @returns the key backup information