From 37c7ae2c9ebf14e9b840d9880aa565fc1c10d6fa Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maxime=20=E2=80=9Cpep=E2=80=9D=20Buquet?= <pep@bouah.net>
Date: Fri, 26 Aug 2022 17:33:36 +0200
Subject: [PATCH] Initial commit
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Signed-off-by: Maxime “pep” Buquet <pep@bouah.net>
---
 aesgcm-dl.py | 60 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)
 create mode 100755 aesgcm-dl.py

diff --git a/aesgcm-dl.py b/aesgcm-dl.py
new file mode 100755
index 0000000..618916c
--- /dev/null
+++ b/aesgcm-dl.py
@@ -0,0 +1,60 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+# vim:fenc=utf-8 et ts=4 sts=4 sw=4
+#
+# Copyright © 2022 Maxime “pep” Buquet <pep@bouah.net>
+#
+# This file is licensed under AGPL-3.0-or-later
+
+"""
+    AESGCM URIs downloader
+"""
+
+import sys
+import asyncio
+from io import BytesIO
+from pathlib import Path
+
+from aiohttp import ClientSession
+from slixmpp.version import __version__ as slixmpp_version
+from slixmpp.plugins.xep_0454 import XEP_0454
+
+
+class InvalidURI(Exception):
+    """Raised when an invalid aesgcm URI is specified"""
+
+    def __init__(self, url) -> None:
+        self.url = url
+
+
+async def handle_file(uri: str) -> None:
+    """Downloads, decrypts, and writes specified URI"""
+
+    try:
+        aesurl, fragment = uri.rsplit('#', 1)
+    except ValueError as exn:
+        raise InvalidURI(uri) from exn
+
+    url = aesurl.replace('aesgcm://', 'https://')
+    filename = Path(url.rsplit('/', 1)[1])
+
+    async with ClientSession(headers={'User-Agent': 'slixmpp ' + slixmpp_version}) as session:
+        async with session.get(url) as response:
+            print(f'Got response for {url}')
+            input_file = BytesIO(await response.read())
+
+    with filename.open('wb') as file:
+        print(f'Writing to {filename}')
+        file.write(XEP_0454.decrypt(input_file, fragment))
+
+
+if __name__ == '__main__':
+    if len(sys.argv) != 2:
+        print('usage: aesgcm-dl <URI>', file=sys.stderr)
+        sys.exit(1)
+
+    try:
+        asyncio.run(handle_file(sys.argv[1]))
+    except InvalidURI as exn:
+        print(f'Invalid aesgcm URI: {exn.url}', file=sys.stderr)
+        sys.exit(2)