Initial Commit

packages/networking/drive/drive-mesh/tests/helpers/signed-chunk.ts

@@ -0,0 +1,73 @@
+/**
+ * Test helper: build a real, signature-valid chunk byte string.
+ *
+ * Uses `@suaveplan/drive-plugin-chunks`' `buildSignedChunk` over a
+ * synthetic but well-formed `Chunk` so `verifyChunkSig` accepts the
+ * result. Fixtures stay deterministic — no random bytes anywhere.
+ */
+
+import {
+    getPublicKey,
+    randomPrivateKey,
+} from "@suaveplan/crypto-curve/ed25519";
+import { buildSignedChunk } from "@suaveplan/drive-plugin-chunks";
+
+export interface Keypair {
+    readonly privKey: Uint8Array;
+    readonly pubKey: Uint8Array;
+}
+
+export function makeKeypair(seed = 1): Keypair {
+    // Deterministic seed via a 32-byte buffer filled with `seed`. Noble
+    // does not strictly require uniformly-random keys for verifiability,
+    // only that the corresponding public key is derived from the same
+    // private key.
+    const priv =
+        seed === 0 ? randomPrivateKey() : new Uint8Array(32).fill(seed & 0xff);
+    const pub = getPublicKey(priv);
+    return { privKey: priv, pubKey: pub };
+}
+
+export function fileIdBytes(hex: string): Uint8Array {
+    if (hex.length !== 64) {
+        throw new Error(`fileId hex must be 64 chars, got ${hex.length}`);
+    }
+    const out = new Uint8Array(32);
+    for (let i = 0; i < 32; i++) {
+        const byteHex = hex.slice(i * 2, i * 2 + 2);
+        out[i] = Number.parseInt(byteHex, 16);
+    }
+    return out;
+}
+
+export function buildChunkBytes(args: {
+    readonly serverPrivKey: Uint8Array;
+    readonly fileIdHex: string;
+    readonly chunkId: number;
+    readonly totalChunks?: number;
+    readonly payload?: Uint8Array;
+}): Uint8Array {
+    const totalChunks = args.totalChunks ?? 8;
+    const payload =
+        args.payload ?? new Uint8Array([args.chunkId & 0xff, 0x42, 0x13, 0x37]);
+    const chunkSize = Math.max(payload.byteLength, 4);
+    const chunk = {
+        metadata: {
+            version: 0x0001,
+            fileId: fileIdBytes(args.fileIdHex),
+            chunkId: args.chunkId,
+            totalChunks,
+            fileSize: BigInt(chunkSize * totalChunks),
+            chunkSize,
+            payloadLen: payload.byteLength,
+            flags: 0,
+            nonce: new Uint8Array(24),
+            aeadTag: new Uint8Array(16),
+        },
+        sig: new Uint8Array(64), // overwritten by buildSignedChunk
+        ciphertext: payload,
+    };
+    return buildSignedChunk(chunk, args.serverPrivKey);
+}
+
+export const TEST_FILE_ID_HEX = "a".repeat(64);