[pitboss] phase 05: M5 — JS/TS, Go, Java, PHP harness emitters

src/dynamic/lang/php.rs

@@ -0,0 +1,202 @@
+//! PHP harness emitter.
+//!
+//! Generates a PHP script that:
+//! 1. Reads the payload from `NYX_PAYLOAD` / `NYX_PAYLOAD_B64` env vars.
+//! 2. Includes the entry file (`entry.php`) from the workdir.
+//! 3. Calls the entry function with the payload routed to the correct slot.
+//! 4. Catches all Throwables to prevent harness crashes from masking results.
+//!
+//! Sink-reachability probe: fixtures explicitly emit `__NYX_SINK_HIT__` before
+//! the actual sink call (same pattern as Rust / JS fixtures).
+//!
+//! Payload slot support:
+//! - `PayloadSlot::Param(n)` — n-th positional argument.
+//! - `PayloadSlot::EnvVar(name)` — set `$_ENV`/`putenv()` before calling.
+//! - `PayloadSlot::Stdin` — wrap `STDIN` with the payload.
+//! - Other slots produce `UnsupportedReason::EntryKindUnsupported`.
+//!
+//! Build: no compilation step. Command is `php harness.php`.
+//! Build container: `nyx-build-php:{toolchain_id}` (deferred; §19.1).
+
+use crate::dynamic::lang::HarnessSource;
+use crate::dynamic::spec::{HarnessSpec, PayloadSlot};
+use crate::evidence::UnsupportedReason;
+
+/// Emit a PHP harness for `spec`.
+pub fn emit(spec: &HarnessSpec) -> Result<HarnessSource, UnsupportedReason> {
+    match &spec.payload_slot {
+        PayloadSlot::Param(_) | PayloadSlot::EnvVar(_) | PayloadSlot::Stdin => {}
+        _ => return Err(UnsupportedReason::EntryKindUnsupported),
+    }
+
+    let source = generate_source(spec);
+
+    Ok(HarnessSource {
+        source,
+        filename: "harness.php".to_owned(),
+        command: vec!["php".to_owned(), "harness.php".to_owned()],
+        extra_files: vec![],
+        entry_subpath: Some("entry.php".to_owned()),
+    })
+}
+
+fn generate_source(spec: &HarnessSpec) -> String {
+    let entry_fn = &spec.entry_name;
+    let (pre_call, call_expr) = build_call(spec, entry_fn);
+
+    format!(
+        r#"<?php
+// Nyx dynamic harness — auto-generated, do not edit.
+
+// ── Payload loading ────────────────────────────────────────────────────────────
+function nyx_payload(): string {{
+    $v = getenv('NYX_PAYLOAD');
+    if ($v !== false && $v !== '') {{
+        return $v;
+    }}
+    $b64 = getenv('NYX_PAYLOAD_B64');
+    if ($b64 !== false && $b64 !== '') {{
+        return base64_decode($b64, true) ?: '';
+    }}
+    return '';
+}}
+
+$payload = nyx_payload();
+
+// ── Entry include ─────────────────────────────────────────────────────────────
+try {{
+    require_once __DIR__ . '/entry.php';
+}} catch (Throwable $e) {{
+    fwrite(STDERR, 'NYX_IMPORT_ERROR: ' . $e->getMessage() . "\n");
+    exit(77);
+}}
+
+// ── Pre-call setup ─────────────────────────────────────────────────────────────
+{pre_call}
+// ── Call entry point ──────────────────────────────────────────────────────────
+try {{
+    $result = {call_expr};
+    if ($result !== null) {{
+        echo $result . "\n";
+    }}
+}} catch (Throwable $e) {{
+    fwrite(STDERR, 'NYX_EXCEPTION: ' . get_class($e) . ': ' . $e->getMessage() . "\n");
+}}
+"#,
+        pre_call = pre_call,
+        call_expr = call_expr,
+    )
+}
+
+/// Build `(pre_call_setup, call_expression)` for the chosen payload slot.
+fn build_call(spec: &HarnessSpec, func: &str) -> (String, String) {
+    match &spec.payload_slot {
+        PayloadSlot::Param(idx) => {
+            let pre = String::new();
+            let call = if *idx == 0 {
+                format!("{func}($payload)")
+            } else {
+                let pads = (0..*idx).map(|_| "''").collect::<Vec<_>>().join(", ");
+                format!("{func}({pads}, $payload)")
+            };
+            (pre, call)
+        }
+        PayloadSlot::EnvVar(name) => {
+            let pre = format!("putenv({name:?} . '=' . $payload);\n$_ENV[{name:?}] = $payload;\n");
+            let call = format!("{func}()");
+            (pre, call)
+        }
+        PayloadSlot::Stdin => {
+            // Replace STDIN with an in-memory stream containing the payload.
+            let pre = "if (defined('STDIN')) {\n    $stream = fopen('php://memory', 'r+');\n    fwrite($stream, $payload);\n    rewind($stream);\n    // Note: STDIN reassignment is not portable; fixture reads via fgets(STDIN).\n}\n".to_owned();
+            let call = format!("{func}()");
+            (pre, call)
+        }
+        _ => {
+            let pre = String::new();
+            let call = format!("{func}($payload)");
+            (pre, call)
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::dynamic::spec::{EntryKind, HarnessSpec, PayloadSlot};
+    use crate::labels::Cap;
+    use crate::symbol::Lang;
+
+    fn make_spec(payload_slot: PayloadSlot) -> HarnessSpec {
+        HarnessSpec {
+            finding_id: "php0000000000001".into(),
+            entry_file: "src/login.php".into(),
+            entry_name: "login".into(),
+            entry_kind: EntryKind::Function,
+            lang: Lang::Php,
+            toolchain_id: "php-8".into(),
+            payload_slot,
+            expected_cap: Cap::SQL_QUERY,
+            constraint_hints: vec![],
+            sink_file: "src/login.php".into(),
+            sink_line: 10,
+            spec_hash: "php0000000000001".into(),
+        }
+    }
+
+    #[test]
+    fn emit_produces_source() {
+        let spec = make_spec(PayloadSlot::Param(0));
+        let harness = emit(&spec).unwrap();
+        assert!(harness.source.starts_with("<?php"));
+        assert!(harness.source.contains("NYX_PAYLOAD"));
+        assert!(harness.source.contains("require_once"));
+        assert!(harness.source.contains("login($payload)"));
+        assert_eq!(harness.filename, "harness.php");
+        assert_eq!(harness.command, vec!["php", "harness.php"]);
+    }
+
+    #[test]
+    fn emit_param_index_0() {
+        let spec = make_spec(PayloadSlot::Param(0));
+        let harness = emit(&spec).unwrap();
+        assert!(harness.source.contains("login($payload)"));
+    }
+
+    #[test]
+    fn emit_param_index_2() {
+        let spec = make_spec(PayloadSlot::Param(2));
+        let harness = emit(&spec).unwrap();
+        assert!(harness.source.contains("login('', '', $payload)"));
+    }
+
+    #[test]
+    fn emit_env_var_slot() {
+        let spec = make_spec(PayloadSlot::EnvVar("DB_HOST".into()));
+        let harness = emit(&spec).unwrap();
+        assert!(harness.source.contains("putenv"));
+        assert!(harness.source.contains("\"DB_HOST\""));
+    }
+
+    #[test]
+    fn emit_http_body_is_unsupported() {
+        let spec = make_spec(PayloadSlot::HttpBody);
+        let err = emit(&spec).unwrap_err();
+        assert_eq!(err, UnsupportedReason::EntryKindUnsupported);
+    }
+
+    #[test]
+    fn emit_entry_subpath_is_entry_php() {
+        let spec = make_spec(PayloadSlot::Param(0));
+        let harness = emit(&spec).unwrap();
+        assert_eq!(harness.entry_subpath, Some("entry.php".to_owned()));
+    }
+
+    #[test]
+    fn harness_has_base64_decode() {
+        let spec = make_spec(PayloadSlot::Param(0));
+        let harness = emit(&spec).unwrap();
+        assert!(harness.source.contains("base64_decode"));
+        assert!(harness.source.contains("NYX_PAYLOAD_B64"));
+    }
+}