giavac’s gists

giavac / create_turn_credentials.py

Created January 16, 2026 15:11

python script to generate ephemeral TURN credentials from a shared secret, with TTL

	#!/usr/bin/env python3
	"""
	Generate ephemeral TURN credentials using a shared secret.

	TURN servers can use time-limited credentials where:
	- Username: <expiry_timestamp>:<username>
	- Password: Base64(HMAC-SHA1(shared_secret, username))

	The expiry timestamp is a Unix timestamp indicating when the credentials expire.
	"""

giavac / stream_server.py

Created December 5, 2025 17:48

WebSocket stream echo server with some test APIs

	import asyncio
	import json
	import ssl

	import websockets
	from websockets.server import WebSocketServerProtocol
	from aiohttp import web

	# Track per-connection state: streamSid + media counter
	client_state = {} # websocket -> {"streamSid": str \| None, "media_count": int}

giavac / custom_encap.lua

Last active November 16, 2025 18:47

Lua plugin for Wireshark. It interprets encapsulated IP frames inside UDP payload. Copy inside the "Wireshark custom plugin" folder and restart Wireshark.

	-- Minimal Custom UDP Encapsulation Dissector
	-- Ignore the first 42 Bytes and treat the UDP payload as an IP frame
	-- This will show the content of encapsulated traffic

	local OUTER_UDP_PORT = 1024 -- default port. You can use "Decode as..." and choose UDP-ENCAP-IP

	local p_skip = Proto("udp_encap_ip", "UDP Encapsulated IP (skip 42 bytes)")

	local HEADER_SIZE = 42
	local ip_dissector = Dissector.get("ip")

giavac / invite_late_offer.xml

Created April 22, 2024 19:33

	<?xml version="1.0" encoding="iso-8859-2" ?>
	<!DOCTYPE scenario SYSTEM "sipp.dtd">

	<scenario name="UAC INVITE + call">

	<send retrans="500">
	<![CDATA[

	INVITE sip:[field3]@[field4]:5061;transport=tls SIP/2.0
	Via: SIP/2.0/[transport] [local_ip]:[local_port];branch=[branch]

giavac / unescape_jsonify_cstring.py

Created July 12, 2023 15:37

Convert a multiline string into a CString usable with C code

	#!/usr/local/bin/python3

	import json
	import argparse

	def rewrite_as_c_string(json_str):
	data = json.loads(json_str)
	formatted_json = json.dumps(data, indent=4)
	c_string = '"' + formatted_json.replace('"', '\\"').replace('\n', '\\n"\n"') + '"'
	return c_string

giavac / extract_opus_and_decode.py

Created July 5, 2023 14:58

Extracts the RTP payload and decodes it into a wav file

	import pyshark
	import opuslib
	import wave
	import argparse

	FRAME_SIZE = 960
	SAMPLE_RATE = 48000
	CHANNEL_COUNT = 1
	SAMPLE_WIDTH = 2

giavac / parse_raw_opus.py

Created July 5, 2023 09:32

Get a raw opus file in, decode it into a wav file

	#!/usr/bin/python3

	import binascii
	import opuslib
	import wave

	total_len = 0

	def process_audio_data(audio_data, wav_file):
	# print(binascii.hexlify(audio_data))

giavac / decrypt_script.sh

Created July 4, 2023 15:42

Bash script to launch a decrypt program

	#!/bin/bash

	gcc decrypt.c -o decrypt -lssl -lz -lcrypto

	encrypted="..."
	tag="..."
	iv="..."
	key="..."

	./decrypt "${encrypted}" "${tag}" "${iv}" "${key}"

giavac / decrypt.c

Last active July 4, 2023 16:26

Decodes from base64, decrypts with key, tag and iv, then decompresses

	#include <stdio.h>
	#include <string.h>
	#include <openssl/evp.h>
	#include <openssl/rand.h>
	#include <openssl/bio.h>
	#include <openssl/buffer.h>
	#include <zlib.h>

	static char base64_decode(const char input, int length, int *output_length) {
	BIO bio, b64;

giavac / ACK_RFC3665

Created July 6, 2018 12:00

ACK as in RFC-3665

	F15 ACK Alice -> Proxy 1

	ACK sip:bob@client.biloxi.example.com SIP/2.0
	Via: SIP/2.0/TCP client.atlanta.example.com:5060;branch=z9hG4bK74b76
	Max-Forwards: 70
	Route: <sip:ss1.atlanta.example.com;lr>,
	<sip:ss2.biloxi.example.com;lr>
	From: Alice <sip:alice@atlanta.example.com>;tag=9fxced76sl
	To: Bob <sip:bob@biloxi.example.com>;tag=314159
	Call-ID: 3848276298220188511@atlanta.example.com

Giacomo Vacca giavac