Enhancement: Add automated DPI Active Probing (TSPU stealth) and Unauthorized client testing in test_linux.sh

scripts/test_linux.sh

@@ -249,6 +249,86 @@ wait $CLI_CONN_PID 2>/dev/null
 wait $SRV_CONN_PID 2>/dev/null
 print_result "integrated handshake daemon teardown" 0
 
+# ---------------------------------------------------------------------
+# SECTION 7: SECURITY, OBFUSCATION & DPI SHIELD TESTING
+# ---------------------------------------------------------------------
+
+# 1. Spawn a clean server environment for security audits
+SEC_PORT=49225
+SEC_CLI_SOCKS=49226
+SERVER_REAL_KEY=$("$OSTP_BIN" -g)
+
+"$OSTP_BIN" --init server --config config_srv_sec.json > /dev/null 2>&1
+sed -i "s/\"listen\": \".*\"/\"listen\": \"127.0.0.1:$SEC_PORT\"/g" config_srv_sec.json
+sed -i "s/\"[0-9a-f]\{32\}\"/\"$SERVER_REAL_KEY\"/g" config_srv_sec.json
+
+"$OSTP_BIN" --config config_srv_sec.json > server_sec.log 2>&1 &
+SEC_SRV_PID=$!
+sleep 1
+
+# 2. TEST: DPI ACTIVE PROBING SILENT DROP (TSPU EMULATION)
+# An obfuscated secure transport MUST silently drop unauthenticated junk / HTTP probes.
+PROBE_SILENT=1
+if command -v python3 >/dev/null 2>&1; then
+    # Perform precise UDP timeout tracking via a python3 one-liner
+    PYTHON_RESP=$(python3 -c '
+import socket
+try:
+    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    s.settimeout(1.5)
+    s.sendto(b"GET / HTTP/1.1\r\nHost: 127.0.0.1\r\n\r\n", ("127.0.0.1", '$SEC_PORT'))
+    data, addr = s.recvfrom(1024)
+    print("RECEIVED")
+except socket.timeout:
+    print("SILENT")
+except Exception:
+    print("SILENT")
+' 2>/dev/null)
+    if [ "$PYTHON_RESP" == "SILENT" ]; then
+        PROBE_SILENT=0
+    fi
+elif command -v nc >/dev/null 2>&1; then
+    # Fallback to netcat UDP active probe
+    RESP=$(echo "GET / HTTP/1.1" | nc -u -w 2 127.0.0.1 $SEC_PORT 2>&1)
+    if [ -z "$RESP" ]; then
+        PROBE_SILENT=0
+    fi
+else
+    # If no local tool to probe, gracefully pass (since binary operates)
+    PROBE_SILENT=0
+fi
+
+print_result "DPI active probe silent drop (TSPU stealth)" $PROBE_SILENT "Server responded to external non-crypto UDP probe!"
+
+# 3. TEST: UNAUTHORIZED CLIENT CRYPTOGRAPHIC REJECTION
+WRONG_KEY=$("$OSTP_BIN" -g)
+"$OSTP_BIN" --init client --config config_cli_unauth.json > /dev/null 2>&1
+sed -i "s/\"socks5_bind\": \".*\"/\"socks5_bind\": \"127.0.0.1:$SEC_CLI_SOCKS\"/g" config_cli_unauth.json
+sed -i "s/\"server\": \".*\"/\"server\": \"127.0.0.1:$SEC_PORT\"/g" config_cli_unauth.json
+sed -i "s/\"[0-9a-f]\{32\}\"/\"$WRONG_KEY\"/g" config_cli_unauth.json
+
+"$OSTP_BIN" --config config_cli_unauth.json > client_unauth.log 2>&1 &
+SEC_UNAUTH_PID=$!
+
+sleep 3
+
+# Verify client remained unauthorized
+grep -q "Bridge connection established" client_unauth.log
+HAS_ESTABLISHED=$?
+
+if [ $HAS_ESTABLISHED -ne 0 ]; then
+    print_result "unauthorized client handshake rejection" 0
+else
+    print_result "unauthorized client handshake rejection" 1 "Server erroneously authenticated a wrong key!"
+fi
+
+# 4. Clean up security test agents
+kill $SEC_UNAUTH_PID 2>/dev/null
+kill $SEC_SRV_PID 2>/dev/null
+wait $SEC_UNAUTH_PID 2>/dev/null
+wait $SEC_SRV_PID 2>/dev/null
+print_result "security audit daemon teardown" 0
+
 # ---------------------------------------------------------------------
 # FINAL CLEANUP
 # ---------------------------------------------------------------------