Fix files, delete, edit in DMs

frontend/src/api/dmApi.ts

@@ -5,7 +5,7 @@ import { importAesGcmKey, aesGcmEncrypt, aesGcmDecrypt } from "../utils/crypto/s
 import { randomBytes } from "../utils/crypto/kdf";
 import { getCurrentKeys } from "../auth/crypto";
 import { request } from "../core/websocket";
-import type { SendDMRequest, DmEnvelope, User } from "../core/types";
+import type { SendDMRequest, DmEnvelope, User, DMEditWebSocketMessage, DmEncryptedJSON, BaseDmEnvelope } from "../core/types";
 import { b64, ub64 } from "../utils/utils";
 
 export async function decryptDm(envelope: DmEnvelope, senderPublicKeyB64: string): Promise<string> {
@@ -46,7 +46,7 @@ export async function fetchDMHistory(userId: number, token: string, limit: numbe
     return data.messages || [];
 }
 
-export async function sendDMViaWebSocket(recipientId: number, recipientPublicKeyB64: string, plaintext: string, authToken: string): Promise<void> {
+export async function sendDMViaWebSocket(recipientId: number, recipientPublicKeyB64: string, plaintext: string, authToken: string, replyToId?: number): Promise<void> {
     const keys = getCurrentKeys();
     if (!keys) throw new Error("Keys not initialized");
 
@@ -69,6 +69,7 @@ export async function sendDMViaWebSocket(recipientId: number, recipientPublicKey
         iv2: b64(wrap.iv),
         wrappedMk: b64(wrap.ciphertext)
     };
+    if (replyToId) payload.replyToId = replyToId;
 
     await request({
         type: "dmSend",
@@ -78,4 +79,93 @@ export async function sendDMViaWebSocket(recipientId: number, recipientPublicKey
         },
         data: payload
     });
-}
+}
+
+export async function sendDmWithFiles(recipientId: number, recipientPublicKeyB64: string, plaintextJson: string, files: File[], token: string): Promise<void> {
+    const keys = getCurrentKeys();
+    if (!keys) throw new Error("Keys not initialized");
+
+    const mk = randomBytes(32);
+    const wkSalt = randomBytes(16);
+    const shared = await ecdhSharedSecret(keys.privateKey, ub64(recipientPublicKeyB64));
+    const wkRaw = await deriveWrappingKey(shared, wkSalt, new Uint8Array([1]));
+    const wk = await importAesGcmKey(wkRaw);
+
+    const wrap = await aesGcmEncrypt(wk, mk);
+
+    const form = new FormData();
+    const names: string[] = [];
+    function sliceBuffer(u8: Uint8Array): ArrayBuffer {
+        return (u8.buffer as ArrayBuffer).slice(u8.byteOffset, u8.byteOffset + u8.byteLength);
+    }
+
+    for (const f of files) {
+        // Encrypt file with same mk
+        const data = new Uint8Array(await f.arrayBuffer());
+        const enc = await aesGcmEncrypt(await importAesGcmKey(mk), data);
+        const blob = new Blob([sliceBuffer(enc.iv), sliceBuffer(enc.ciphertext)], { type: "application/octet-stream" });
+        const serverName = f.name; // server uses provided name
+        names.push(serverName);
+        form.append("files", new File([blob], serverName));
+    }
+    form.append("fileNames", JSON.stringify(names));
+
+    // Merge files metadata into plaintext JSON and encrypt
+    let obj: DmEncryptedJSON;
+    try {
+        obj = JSON.parse(plaintextJson);
+    } catch {
+        obj = { type: "text", data: { content: String(plaintextJson) } };
+    }
+
+    const encMsg = await aesGcmEncrypt(await importAesGcmKey(mk), new TextEncoder().encode(JSON.stringify(obj)));
+    form.append("dm_payload", JSON.stringify({
+        recipientId: recipientId,
+        iv: b64(encMsg.iv),
+        ciphertext: b64(encMsg.ciphertext),
+        salt: b64(wkSalt),
+        iv2: b64(wrap.iv),
+        wrappedMk: b64(wrap.ciphertext)
+    } satisfies BaseDmEnvelope));
+
+    await fetch(`${API_BASE_URL}/dm/send`, {
+        method: "POST",
+        headers: getAuthHeaders(token, false),
+        body: form
+    });
+}
+
+export async function editDmEnvelope(id: number, recipientPublicKeyB64: string, newPlaintextJson: string, authToken: string): Promise<void> {
+    const keys = getCurrentKeys();
+    if (!keys) throw new Error("Keys not initialized");
+
+    // We cannot reuse the old mk safely without knowing it; generate a fresh mk and wrap
+    const mk = randomBytes(32);
+    const wkSalt = randomBytes(16);
+    const shared = await ecdhSharedSecret(keys.privateKey, ub64(recipientPublicKeyB64));
+    const wkRaw = await deriveWrappingKey(shared, wkSalt, new Uint8Array([1]));
+    const wk = await importAesGcmKey(wkRaw);
+    const encMsg = await aesGcmEncrypt(await importAesGcmKey(mk), new TextEncoder().encode(newPlaintextJson));
+    const wrap = await aesGcmEncrypt(wk, mk);
+
+    await request({
+        type: "dmEdit",
+        credentials: { scheme: "Bearer", credentials: authToken },
+        data: {
+            id,
+            iv: b64(encMsg.iv),
+            ciphertext: b64(encMsg.ciphertext),
+            iv2: b64(wrap.iv),
+            wrappedMk: b64(wrap.ciphertext),
+            salt: b64(wkSalt)
+        }
+    } as DMEditWebSocketMessage);
+}
+
+export async function deleteDmEnvelope(id: number, recipientId: number, authToken: string): Promise<void> {
+    await request({
+        type: "dmDelete",
+        credentials: { scheme: "Bearer", credentials: authToken },
+        data: { id, recipientId }
+    });
+}