Update to latest engine. Add sync-v2. Various fixes.

src/utils/syncing/shared/client.ts

@@ -0,0 +1,122 @@
+import { binToHex, flattenBinArray, secp256k1, sha256 } from "@bitauth/libauth";
+
+import { toExtendedJson } from "@xo-cash/utils";
+import type { WriteRequest } from "../types.js";
+
+export type AuthenticatedRequestHeaders = {
+  'X-Public-Key': string;
+  'X-Timestamp': string;
+  'X-Signature': string;
+};
+
+export type SignedPayload = { publicKey: string; signature: string };
+
+export abstract class SyncClient {
+
+  abstract connect(): Promise<void>;
+  abstract disconnect(): Promise<void>;
+  abstract write(resourceId: string, value: Record<string, unknown>): Promise<unknown>;
+  abstract read(resourceId: string): Promise<unknown>;
+  abstract subscribe(resourceId: string): Promise<void>;
+  abstract unsubscribe(resourceId: string): Promise<unknown>;
+
+  /**
+   * Derives the resource private key from the private key and resource ID
+   * @param privateKey - The private key to derive the resource private key from
+   * @param resourceId - The resource ID to derive the resource private key from
+   * @returns The resource private key
+   */
+  static deriveResourcePrivateKey(privateKey: Uint8Array, resourceId: string): Uint8Array {
+    // Convert the resource ID to bytes
+    const resourceIdBytes = new TextEncoder().encode(resourceId);
+
+    // Hash the private key and resource ID
+    return sha256.hash(flattenBinArray([ privateKey, resourceIdBytes ]));
+  }
+
+  /**
+   * Signs a payload with the private key and returns the public key and signature
+   * @param privateKey - The private key to sign the payload with
+   * @param payload - The payload to sign
+   * @returns The public key and signature
+   */
+  static signPayload(privateKey: Uint8Array, payload: string): SignedPayload {
+    // Convert the payload to Binary and hash it
+    const payloadHash = sha256.hash(new TextEncoder().encode(payload));
+
+    // Derive the public key
+    const publicKey = secp256k1.derivePublicKeyCompressed(privateKey);
+    
+    // If the public key is a string, throw an error
+    if (typeof publicKey === 'string') {
+      throw new Error('Failed to derive public key');
+    }
+
+    // Sign the payload
+    const signature = secp256k1.signMessageHashDER(privateKey, payloadHash);
+
+    // If the signature is a string, throw an error
+    if (typeof signature === 'string') {
+      throw new Error('Failed to sign message');
+    }
+
+    return {
+      publicKey: binToHex(publicKey),
+      signature: binToHex(signature),
+    };
+  }
+
+  /**
+   * Signs a write request with the private key and returns the write request
+   * @param privateKey - The private key to sign the write request with
+   * @param resourceId - The resource ID to write to
+   * @param value - The value to write
+   * @returns The write request
+   */
+  static signWriteRequest(privateKey: Uint8Array, resourceId: string, value: Uint8Array): WriteRequest {
+    // Derive the resource private key
+    const derivedKey = this.deriveResourcePrivateKey(privateKey, resourceId);
+
+    // Create the payload
+    const timestamp = Date.now();
+    const payload = `${timestamp}:${resourceId}:${toExtendedJson(value)}`;
+
+    // Sign the payload
+    const { publicKey, signature } = this.signPayload(derivedKey, payload);
+
+    return { 
+      id: resourceId,
+      value,
+      publicKey,
+      timestamp,
+      signature,
+    };
+  }
+
+  /**
+   * Signs a request with the private key and returns the public key, timestamp, and signature
+   * @param privateKey - The private key to sign the request with
+   * @param path - The path of the request
+   * @param body - The body of the request
+   * @returns The public key, timestamp, and signature
+   */
+  static signRequest(privateKey: Uint8Array, path: string, body: unknown): AuthenticatedRequestHeaders {
+    // Create the payload
+    const timestamp = Date.now();
+
+    // Convert the body to a string if it isn't already a string
+    const bodyStr = typeof body === 'string' ? body : toExtendedJson(body);
+
+    // Create the payload as `Timestamp:Path:Body`
+    const payload = `${timestamp}:${path}:${bodyStr}`;
+
+    // Sign the payload
+    const { publicKey, signature } = this.signPayload(privateKey, payload);
+
+    return {
+      'X-Public-Key': publicKey,
+      'X-Timestamp': timestamp.toString(),
+      'X-Signature': signature,
+    };
+  }
+}