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/fixtures/cross_file_data_exfil_split/caller_body_tainted.js

@@ -0,0 +1,16 @@
+var express = require('express');
+var { forward } = require('./helper');
+
+var app = express();
+
+// Tainted body, fixed URL: DATA_EXFIL must fire on the body flow.  The
+// session cookie is a Sensitive-tier source, so taint carries the
+// DATA_EXFIL bit through to the wrapper's body-gate.  SSRF must NOT
+// fire — the URL is a hardcoded literal and the cap-vs-position split
+// keeps the body's taint from leaking onto the URL's gate.
+app.get('/sync', function(req, res) {
+    var sid = req.cookies.session;
+    var payload = JSON.stringify({ session: sid });
+    forward('https://analytics.internal/track', payload);
+    res.status(204).end();
+});

tests/fixtures/cross_file_data_exfil_split/caller_url_tainted.js

@@ -0,0 +1,14 @@
+var express = require('express');
+var { forward } = require('./helper');
+
+var app = express();
+
+// Tainted URL, fixed body: SSRF must fire on the URL flow.  DATA_EXFIL
+// must NOT fire — the body is a literal string, not a sensitive source,
+// and the cap-vs-position split through the wrapper's summary keeps the
+// URL's taint from leaking onto the body's gate.
+app.get('/proxy', function(req, res) {
+    var taintedUrl = req.query.url;
+    forward(taintedUrl, '{"ok":true}');
+    res.status(204).end();
+});

tests/fixtures/cross_file_data_exfil_split/expectations.json

@@ -0,0 +1,22 @@
+{
+  "required_findings": [
+    { "id_prefix": "taint-unsanitised-flow", "min_count": 1 },
+    { "id_prefix": "taint-data-exfiltration", "min_count": 1 }
+  ],
+  "forbidden_findings": [
+    {
+      "id_prefix": "taint-data-exfiltration",
+      "file_glob": "**/caller_url_tainted.js"
+    },
+    {
+      "id_prefix": "taint-unsanitised-flow",
+      "file_glob": "**/caller_body_tainted.js"
+    }
+  ],
+  "performance_expectations": {
+    "max_ms_no_index": 1500,
+    "max_ms_index_cold": 2000,
+    "max_ms_index_warm": 800,
+    "ci_mode": "lenient"
+  }
+}

tests/fixtures/cross_file_data_exfil_split/helper.js

@@ -0,0 +1,10 @@
+// Wrapper around `fetch` whose two parameters target distinct gated-sink
+// classes on the inner call: `url` is the SSRF gate's destination; `body`
+// is the DATA_EXFIL gate's payload. Pass-1 SSA summary extraction lifts
+// the per-position cap split into `param_to_gate_filters` so cross-file
+// callers can attribute SSRF vs DATA_EXFIL per argument.
+function forward(url, body) {
+    fetch(url, { method: 'POST', body: body });
+}
+
+module.exports = { forward };