java-topology/defects/vlc-0003/unit/VlcDsmCredentialLogTest.java

import java.util.ArrayList;
import java.util.List;

/**
 * Test for vlc-0003: CWE-312 SMB credentials logged verbatim via msg_Warn()
 * in modules/access/dsm/access.c (VLC SMB1 DSM access module).
 *
 * Pattern:
 *   msg_Warn( p_access, "Creds: username = '%s', domain = '%s'",
 *            psz_login, psz_domain );
 *
 * This line executes on every successful SMB1 login, writing plaintext
 * username + domain to our VLC log (debug file, syslog, or any log sink).
 * VLC debug logs are routinely included in bug reports, exposing SMB
 * identity information (username + domain) to third parties. In corporate
 * environments, domain/username is sufficient to enumerate valid accounts
 * and facilitate lateral movement.
 *
 * Fix: remove our credential log line. Successful login is implicit from
 * reaching this code path without error. Username and domain do not need
 * to be announced in the log after authentication completes.
 *
 * Compile and run (no build tool required):
 *   javac defects/vlc-0003/unit/VlcDsmCredentialLogTest.java -d /tmp/vlc-0003
 *   java -cp /tmp/vlc-0003 VlcDsmCredentialLogTest
 */
public class VlcDsmCredentialLogTest {

    private static int passed = 0;
    private static int failed = 0;

    // --- Simulated VLC log sink ---

    static class LogSink {
        private final List<String> messages = new ArrayList<>();

        void warn(String fmt, Object... args) {
            messages.add(String.format(fmt, args));
        }

        boolean containsText(String text) {
            for (String m : messages) {
                if (m.contains(text)) return true;
            }
            return false;
        }

        int size() { return messages.size(); }
    }

    // --- Defective: logs username + domain via msg_Warn ---

    static void smbLoginDefective(LogSink log, String username, String domain) {
        // smb_connect() succeeds ...
        // smb_session_is_guest() returns 0 (not guest)
        boolean isGuest = false;
        if (!isGuest) {
            // CWE-312 site — logs credentials verbatim
            log.warn("Creds: username = '%s', domain = '%s'", username, domain);
        }
        // vlc_credential_store(...)
    }

    // --- Fixed: credential log line removed ---

    static void smbLoginFixed(LogSink log, String username, String domain) {
        // smb_connect() succeeds ...
        // No credential log line
        // vlc_credential_store(...)
        boolean isGuest = false;
        // isGuest path still logs the guest warning, but not credentials
    }

    // --- Tests ---

    static void testDefectiveLogsUsername() {
        LogSink log = new LogSink();
        smbLoginDefective(log, "alice", "CORP");
        check("defective path must log the username (confirms CWE-312 site present)",
              log.containsText("alice"));
    }

    static void testDefectiveLogsDomain() {
        LogSink log = new LogSink();
        smbLoginDefective(log, "alice", "CORP");
        check("defective path must log the domain name",
              log.containsText("CORP"));
    }

    static void testFixedDoesNotLogUsername() {
        LogSink log = new LogSink();
        smbLoginFixed(log, "alice", "CORP");
        check("fixed path must NOT log the SMB username",
              !log.containsText("alice"));
    }

    static void testFixedDoesNotLogDomain() {
        LogSink log = new LogSink();
        smbLoginFixed(log, "alice", "CORP");
        check("fixed path must NOT log the SMB domain",
              !log.containsText("CORP"));
    }

    static void testFixedSuppressesAllCredentials() {
        // Simulate 100 SMB1 logins — none should produce credential log entries
        String[] usernames = new String[100];
        String[] domains   = new String[100];
        for (int i = 0; i < 100; i++) {
            usernames[i] = "user" + i;
            domains[i]   = "DOMAIN" + i;
        }

        int leaks = 0;
        for (int i = 0; i < 100; i++) {
            LogSink log = new LogSink();
            smbLoginFixed(log, usernames[i], domains[i]);
            if (log.containsText(usernames[i]) || log.containsText(domains[i])) {
                leaks++;
            }
        }
        check("fixed path must produce 0 credential leaks across 100 logins (got " + leaks + ")",
              leaks == 0);
    }

    static void testFixedProducesNoLogLines() {
        LogSink log = new LogSink();
        smbLoginFixed(log, "administrator", "WORKGROUP");
        check("fixed login produces no log output (login success is implicit)",
              log.size() == 0);
    }

    // --- Harness ---

    static void check(String desc, boolean cond) {
        if (cond) {
            System.out.println("  PASS: " + desc);
            passed++;
        } else {
            System.out.println("  FAIL: " + desc);
            failed++;
        }
    }

    public static void main(String[] args) {
        System.out.println("=== VlcDsmCredentialLogTest (vlc-0003, CWE-312 SMB credentials logged) ===\n");

        testDefectiveLogsUsername();
        testDefectiveLogsDomain();
        testFixedDoesNotLogUsername();
        testFixedDoesNotLogDomain();
        testFixedSuppressesAllCredentials();
        testFixedProducesNoLogLines();

        System.out.println("\n--- " + passed + " passed, " + failed + " failed ---");
        if (failed > 0) System.exit(1);
    }
}