fix potential ssrf attack in #12663

import time

import datetime

import uvicorn

import ipaddress

import requests

import gradio as gr

from threading import Lock

from io import BytesIO

def decode_base64_to_image(encoding):

    def verify_url(url):

        import socket

        from urllib.parse import urlparse

        try:

            parsed_url = urlparse(url)

            domain_name = parsed_url.netloc

            host = socket.gethostbyname_ex(domain_name)

            for ip in host[2]:

                ip_addr = ipaddress.ip_address(ip)

                # https://docs.python.org/3/library/ipaddress.html#ipaddress.IPv4Address.is_global

                if not ip_addr.is_global:

                    return False

        except Exception:

            return False

        return True

    if encoding.startswith("http://") or encoding.startswith("https://"):

        import requests

        if not verify_url(encoding):

            raise HTTPException(status_code=500, detail="Invalid image url")

        response = requests.get(encoding, timeout=30, headers={'user-agent':'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3202.94 Safari/537.36'})

        try:

            image = Image.open(BytesIO(response.content))