Initial import

src/parser.ts

@@ -0,0 +1,81 @@
+import { equalBytes } from "@noble/ciphers/utils.js";
+import { bytesToHex, hexToBytes } from "@noble/hashes/utils.js";
+
+export {
+  bytesToHex,
+  hexToBytes,
+  equalBytes
+};
+
+export const base64ToBytes = (base64: string): Uint8Array => {
+    const binaryString = atob(base64);
+    const bytes = new Uint8Array(binaryString.length);
+    for (let i = 0; i < binaryString.length; i++) {
+        bytes[i] = binaryString.charCodeAt(i);
+    }
+    return bytes;
+}
+
+export class BufferReader {
+  private buffer: Uint8Array;
+  private offset: number;
+
+  constructor(buffer: Uint8Array) {
+    this.buffer = buffer;
+    this.offset = 0;
+  }
+
+  public readByte(): number {
+    return this.buffer[this.offset++];
+  }
+
+  public readBytes(length?: number): Uint8Array {
+    if (length === undefined) {
+      length = this.buffer.length - this.offset;
+    }
+    const bytes = this.buffer.slice(this.offset, this.offset + length);
+    this.offset += length;
+    return bytes;
+}
+
+  public hasMore(): boolean {
+    return this.offset < this.buffer.length;
+  }
+
+  public remainingBytes(): number {
+    return this.buffer.length - this.offset;
+  }
+
+  public peekByte(): number {
+    return this.buffer[this.offset];
+  }
+
+  public readUint16LE(): number {
+    const value = this.buffer[this.offset] | (this.buffer[this.offset + 1] << 8);
+    this.offset += 2;
+    return value;
+  }
+
+  public readUint32LE(): number {
+    const value = this.buffer[this.offset] | (this.buffer[this.offset + 1] << 8) | (this.buffer[this.offset + 2] << 16) | (this.buffer[this.offset + 3] << 24);
+    this.offset += 4;
+    return value;
+  }
+
+  public readInt16LE(): number {
+    const value = this.buffer[this.offset] | (this.buffer[this.offset + 1] << 8);
+    this.offset += 2;
+    return value < 0x8000 ? value : value - 0x10000;
+  }
+
+  public readInt32LE(): number {
+    const value = this.buffer[this.offset] | (this.buffer[this.offset + 1] << 8) | (this.buffer[this.offset + 2] << 16) | (this.buffer[this.offset + 3] << 24);
+    this.offset += 4;
+    return value < 0x80000000 ? value : value - 0x100000000;
+  }
+
+  public readTimestamp(): Date {
+    const timestamp = this.readUint32LE();
+    return new Date(timestamp * 1000);
+  }
+}