Added Cap::DATA_EXFIL and taint fp and fn fixes on real repos (#59)

* feat: Enhance data exfiltration detection with source sensitivity gating for cookies and headers

* feat: Implement cross-file data exfiltration detection with parameter-specific gate filters

* feat: Add calibration tests and refine DATA_EXFIL severity scoring logic

* feat: Introduce per-detector configuration for data exfiltration suppression

* feat: Enhance DATA_EXFIL findings with destination field tracking in diagnostics and SARIF output

* feat: Add tainted body and URL handling for data exfiltration detection

* feat: Add integration tests and fixtures for DATA_EXFIL and SSRF detection in Go

* feat: Add Java integration tests and fixtures for DATA_EXFIL detection across multiple HTTP clients

* feat: Add synthetic externals handling for closure-captured variables in SSA

* feat: Implement closure-based suppression for resource leak findings

* feat: Add regression guards for shell-injection and taint propagation in for-of destructure patterns

* feat: Implement constructor cap narrowing for data exfiltration detection in HTTP request builders

* feat: Add gated sinks for data exfiltration detection in C and C++ using curl_easy_setopt

* feat: Implement DATA_EXFIL cap parity for backwards analysis and add integration tests

* feat: Add data exfiltration sinks for various languages and enhance documentation

* refactor: Simplify formatting and improve readability in various files

* refactor: Improve readability by simplifying conditional statements and adding clippy linting

* docs: Update CHANGELOG and comments for data exfiltration features and configuration

* docs: Clarify configuration instructions for data exfiltration trusted destinations

* docs: Enhance comments for evidence routing logic in data exfiltration

tests/benchmark/corpus/python/data_exfil/exfil_httpx_async_post_env.py

@@ -0,0 +1,17 @@
+import os
+from fastapi import FastAPI, Request
+import httpx
+
+app = FastAPI()
+
+
+# DATA_EXFIL: env-config secret flows into the json kwarg of an async
+# httpx.AsyncClient().post() at a fixed destination URL.
+@app.post('/sync-async')
+async def sync_async(req: Request):
+    api_key = os.environ.get('UPSTREAM_API_KEY')
+    await httpx.AsyncClient().post(
+        'https://upstream.internal/ingest',
+        json={'api_key': api_key},
+    )
+    return {'ok': True}

tests/benchmark/corpus/python/data_exfil/exfil_requests_post_env_dict.py

@@ -0,0 +1,16 @@
+import os
+import requests
+from flask import Flask
+
+app = Flask(__name__)
+
+
+# DATA_EXFIL: env-config secrets accumulate into a dict, then flow as the
+# json kwarg of requests.post() at a fixed destination URL.
+@app.route('/upload-config', methods=['POST'])
+def upload_config():
+    payload = {}
+    payload['api_key'] = os.environ.get('UPSTREAM_API_KEY')
+    payload['region'] = os.environ.get('UPSTREAM_REGION')
+    requests.post('https://api.internal/ingest', json=payload)
+    return 'ok'

tests/benchmark/corpus/python/safe/safe_data_exfil_user_input_echo.py

@@ -0,0 +1,14 @@
+import requests
+from flask import Flask, request
+
+app = Flask(__name__)
+
+
+# DATA_EXFIL safe: plain user input echoed into a fixed-destination
+# requests.post body must not fire. Sensitivity-gate strips the cap
+# because the source is Plain-tier (raw user input).
+@app.route('/forward', methods=['POST'])
+def forward():
+    message = request.form.get('message')
+    requests.post('https://telemetry.internal/forward', json={'message': message})
+    return 'ok'