README: what a backup does with a file deleted in Ente (closes #242)

A file deleted in Ente keeps its original at its save path, and the JSON
beside it. The next run removes its symlinks from the collection
directories.

Model: opus-5-5

README.md

@@ -671,6 +671,9 @@ but letters and digits, or when it is longer than 16 characters.
 When the date or the time zone changes, the next run stores the original at its
 new path and leaves the old copy where it is.
 
+A file deleted in Ente keeps its original at its save path, and the JSON beside
+it. The next run removes its symlinks from the collection directories.
+
 The library gives the same path as `photo.savePath` and writes it with
 `photo.download()` (see "A photo's content").
 

src/api/client.ts

@@ -354,13 +354,7 @@ export class ApiClient {
         });
     }
 
-    // `contentMD5` is the value given to `getUploadURL`. The server signs it
-    // into the URL, and storage refuses a PUT without that `Content-MD5`.
-    async putFile(
-        presignedURL: string,
-        data: Uint8Array,
-        contentMD5: string,
-    ): Promise<void> {
+    async putFile(presignedURL: string, data: Uint8Array): Promise<void> {
         // Idempotent despite being a write: a presigned PUT stores one whole
         // object at one key in one request, so replaying it either overwrites
         // the same bytes or lands them for the first time. There is no partial
@@ -376,7 +370,6 @@ export class ApiClient {
                     headers: {
                         "Content-Type": "application/octet-stream",
                         "Content-Length": String(data.length),
-                        "Content-MD5": contentMD5,
                     },
                     body: data,
                     signal: AbortSignal.timeout(this.requestTimeoutMs),

src/thumbnails.ts

@@ -325,7 +325,7 @@ export const fixMissingThumbnails = async (
                 ciphertext.length,
                 md5,
             );
-            await api.putFile(url, ciphertext, md5);
+            await api.putFile(url, ciphertext);
             await api.updateThumbnail(file.id, objectKey, toBase64(header));
 
             log(`[${collectionName}] Thumbnail uploaded for ${title}`);

test/api/client.test.ts

@@ -780,7 +780,7 @@ describe("ApiClient timeouts", () => {
 
         await client.getJSON("/a");
         await client.postJSON("/b", {});
-        await client.putFile("https://s3.example/x", new Uint8Array([1]), "m");
+        await client.putFile("https://s3.example/x", new Uint8Array([1]));
         await client.putJSON("/c", {});
 
         for (const call of calls) {
@@ -825,8 +825,7 @@ describe("ApiClient timeouts", () => {
             [
                 "putFile",
                 () => new Response(null, { status: 200 }),
-                (c) =>
-                    c.putFile("https://s3.example/x", new Uint8Array([1]), "m"),
+                (c) => c.putFile("https://s3.example/x", new Uint8Array([1])),
             ],
             [
                 "getFileStream",
@@ -1050,7 +1049,7 @@ describe("ApiClient error typing", () => {
         const client = new ApiClient({ fetch, retry: noWait });
 
         const err: unknown = await client
-            .putFile("https://s3.example/obj", new Uint8Array([1, 2]), "m")
+            .putFile("https://s3.example/obj", new Uint8Array([1, 2]))
             .catch((e: unknown) => e);
 
         expect(err).toBeInstanceOf(ApiError);
@@ -1068,11 +1067,7 @@ describe("ApiClient error typing", () => {
         );
         const client = new ApiClient({ fetch, retry: noWait });
 
-        await client.putFile(
-            "https://s3.example/obj",
-            new Uint8Array([1, 2]),
-            "m",
-        );
+        await client.putFile("https://s3.example/obj", new Uint8Array([1, 2]));
         expect(calls).toHaveLength(2);
     });
 
@@ -1282,7 +1277,6 @@ describe("ApiClient onRequest", () => {
         await client.putFile(
             "https://s3.example/obj?X-Amz-Signature=abc",
             new Uint8Array([1, 2]),
-            "m",
         );
 
         expect(requests).toEqual([

test/api/upload.test.ts

@@ -80,20 +80,13 @@ describe("ApiClient.putFile", () => {
         const client = new ApiClient({ fetch, authToken: "secret-tok" });
         const data = new Uint8Array([1, 2, 3, 4, 5]);
 
-        await client.putFile(
-            "https://s3.example.com/presigned?sig=abc",
-            data,
-            "md5base64==",
-        );
+        await client.putFile("https://s3.example.com/presigned?sig=abc", data);
 
         expect(calls[0]!.url).toBe("https://s3.example.com/presigned?sig=abc");
         expect(calls[0]!.init?.method).toBe("PUT");
         const headers = new Headers(calls[0]!.init?.headers as HeadersInit);
         expect(headers.get("Content-Type")).toBe("application/octet-stream");
         expect(headers.get("Content-Length")).toBe("5");
-        // The server signs the MD5 into the URL; storage refuses the PUT
-        // without it.
-        expect(headers.get("Content-MD5")).toBe("md5base64==");
         // Must NOT leak auth headers to S3
         expect(headers.has("X-Auth-Token")).toBe(false);
         expect(headers.has("X-Client-Package")).toBe(false);
@@ -106,11 +99,7 @@ describe("ApiClient.putFile", () => {
         const client = new ApiClient({ fetch });
 
         await expect(
-            client.putFile(
-                "https://s3.example.com/bad",
-                new Uint8Array(10),
-                "md5base64==",
-            ),
+            client.putFile("https://s3.example.com/bad", new Uint8Array(10)),
         ).rejects.toThrow(/403/);
     });
 });

test/thumbnails/thumbnails.test.ts

@@ -273,7 +273,6 @@ const buildThumbMock = async (opts?: {
 
 const buildThumbFetch = (m: ThumbMockState) => {
     let srpServer: SrpServer;
-    let signedMD5: string | undefined;
 
     return (async (
         input: RequestInfo | URL,
@@ -366,9 +365,8 @@ const buildThumbFetch = (m: ThumbMockState) => {
             return new Response("not found", { status: 404 });
         }
 
-        // Upload URL minting. The real server signs the MD5 into the URL.
+        // Upload URL minting
         if (path === "/files/upload-url") {
-            signedMD5 = JSON.parse(init?.body as string).contentMD5;
             return json({
                 objectKey: `42/thumb-${Date.now()}`,
                 url: "https://s3.mock.test/presigned-put",
@@ -377,11 +375,6 @@ const buildThumbFetch = (m: ThumbMockState) => {
 
         // Presigned PUT (S3 upload)
         if (url.startsWith("https://s3.mock.test/")) {
-            // Storage refuses a PUT that lacks the signed `Content-MD5`.
-            const headers = new Headers(init?.headers);
-            if (headers.get("Content-MD5") !== signedMD5) {
-                return new Response("AccessDenied", { status: 400 });
-            }
             const body = init?.body;
             // Store the uploaded bytes for later inspection
             if (body instanceof Uint8Array) {