mirror of
https://github.com/ar0x4/azproxy/
synced 2026-06-28 15:09:58 +00:00
ar0x4
94 lines
2.6 KiB
Python
94 lines
2.6 KiB
Python
"""
|
|
Interceptor — request rewriting for Azure Function proxy routing.
|
|
|
|
Takes an incoming HTTP request targeting a real destination and rewrites it
|
|
to route through an Azure Function endpoint instead.
|
|
"""
|
|
from __future__ import annotations
|
|
|
|
from dataclasses import dataclass
|
|
from urllib.parse import urlparse
|
|
|
|
|
|
@dataclass
|
|
class RewrittenRequest:
|
|
"""A request rewritten to target an Azure Function endpoint."""
|
|
|
|
method: str
|
|
url: str # Azure Function endpoint URL
|
|
headers: dict[str, str]
|
|
body: bytes
|
|
|
|
|
|
def rewrite_request(
|
|
method: str,
|
|
original_url: str,
|
|
headers: dict[str, str],
|
|
body: bytes,
|
|
function_endpoint: str,
|
|
auth_key: str,
|
|
) -> RewrittenRequest:
|
|
"""
|
|
Rewrite an HTTP request to route through an Azure Function proxy.
|
|
|
|
Original request:
|
|
GET https://target.com/api/users HTTP/1.1
|
|
Host: target.com
|
|
User-Agent: curl/8.0
|
|
|
|
Rewritten request:
|
|
GET https://azureprox-xxx-westeurope-func.azurewebsites.net/api/proxy HTTP/1.1
|
|
Host: azureprox-xxx-westeurope-func.azurewebsites.net
|
|
User-Agent: curl/8.0
|
|
X-AzureProx-Target: https://target.com/api/users
|
|
X-AzureProx-Key: <auth_key>
|
|
|
|
The Azure Function then:
|
|
1. Reads X-AzureProx-Target to know where to forward
|
|
2. Validates X-AzureProx-Key
|
|
3. Strips proxy headers
|
|
4. Forwards the request with the remaining headers
|
|
"""
|
|
rewritten_headers = {}
|
|
|
|
# Copy original headers, except Host (will be set by httpx on the function side)
|
|
for key, value in headers.items():
|
|
k_lower = key.lower()
|
|
if k_lower == "host":
|
|
continue
|
|
# Don't forward proxy-specific headers
|
|
if k_lower in ("proxy-connection", "proxy-authorization"):
|
|
continue
|
|
rewritten_headers[key] = value
|
|
|
|
# Add our control headers
|
|
rewritten_headers["X-AzureProx-Target"] = original_url
|
|
rewritten_headers["X-AzureProx-Key"] = auth_key
|
|
|
|
# Set correct Host for the function endpoint
|
|
parsed = urlparse(function_endpoint)
|
|
rewritten_headers["Host"] = parsed.hostname
|
|
|
|
return RewrittenRequest(
|
|
method=method,
|
|
url=function_endpoint,
|
|
headers=rewritten_headers,
|
|
body=body,
|
|
)
|
|
|
|
|
|
def parse_proxy_request_line(line: str) -> tuple[str, str, str]:
|
|
"""
|
|
Parse an HTTP proxy request line.
|
|
|
|
Proxy requests come in absolute-URI form:
|
|
GET http://target.com/path HTTP/1.1
|
|
CONNECT target.com:443 HTTP/1.1
|
|
|
|
Returns (method, url, http_version)
|
|
"""
|
|
parts = line.strip().split(" ", 2)
|
|
if len(parts) != 3:
|
|
raise ValueError(f"Malformed request line: {line!r}")
|
|
return parts[0], parts[1], parts[2]
|