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

/**
 * Test for esp-idf-0002: CWE-312 HTTP Digest auth password logged verbatim
 * in components/esp_http_client/lib/http_auth.c http_auth_digest().
 *
 * Pattern:
 *   ESP_LOGD(TAG, "%s %s %s %s", "Digest", username, auth_data->realm, password)
 *
 * During HTTP Digest authentication setup the plaintext password is emitted
 * to serial/JTAG when debug logging is active. Unlike Basic Auth the password
 * should never leave the chip except as part of the one-way digest hash.
 *
 * Fix: remove the offending ESP_LOGD line. Logging the digest hash result
 * (ha1/response) would be safe; logging the raw password is not.
 *
 * Compile and run (no build tool required):
 *   javac defects/esp-idf-0002/test/EspIdf0002Test.java -d /tmp/esp-idf-0002
 *   java -cp /tmp/esp-idf-0002 EspIdf0002Test
 */
public class EspIdf0002Test {

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

    // --- Simulated log collector ---

    static class LogCollector {
        private final List<String> lines = new ArrayList<>();

        void logd(String tag, String fmt, Object... args) {
            lines.add(String.format(fmt, args));
        }

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

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

    /** Trivial stand-in for MD5 hex — actual hash value irrelevant for this test. */
    static String mockMd5(String input) {
        return Integer.toHexString(input.hashCode() & 0x7fffffff);
    }

    // --- Defective: logs username + realm + password ---

    static String computeDigestDefective(
            String username, String realm, String password, LogCollector log) {
        String ha1 = mockMd5(username + ":" + realm + ":" + password);
        log.logd("HTTP_AUTH", "%s %s %s %s", "Digest", username, realm, password); // CWE-312
        String ha2 = mockMd5("GET:/api/data");
        return mockMd5(ha1 + ":nonce123:" + ha2);
    }

    // --- Fixed: no password in any log statement ---

    static String computeDigestFixed(
            String username, String realm, String password, LogCollector log) {
        String ha1 = mockMd5(username + ":" + realm + ":" + password);
        // ESP_LOGD with password removed — fix for esp-idf-0002
        String ha2 = mockMd5("GET:/api/data");
        return mockMd5(ha1 + ":nonce123:" + ha2);
    }

    // --- Tests ---

    static void testDefectiveLogsPassword() {
        LogCollector log = new LogCollector();
        computeDigestDefective("alice", "testrealm@host.com", "hunter2", log);
        check("defective must log the password (confirms CWE-312 site is present)",
            log.containsText("hunter2"));
    }

    static void testFixedDoesNotLogPassword() {
        LogCollector log = new LogCollector();
        computeDigestFixed("alice", "testrealm@host.com", "hunter2", log);
        check("fixed must NOT log the HTTP auth password",
            !log.containsText("hunter2"));
    }

    static void testDefectiveAlsoExposesUsername() {
        LogCollector log = new LogCollector();
        computeDigestDefective("alice", "testrealm@host.com", "hunter2", log);
        // The combined log line is the real risk (username + realm + password together)
        check("defective log line includes username (combined exposure risk)",
            log.containsText("alice"));
    }

    static void testFixedProducesNoLogLines() {
        LogCollector log = new LogCollector();
        computeDigestFixed("alice", "testrealm@host.com", "hunter2", log);
        check("fixed digest computation emits no log lines",
            log.size() == 0);
    }

    static void testBothReturnSameDigest() {
        LogCollector log1 = new LogCollector();
        LogCollector log2 = new LogCollector();
        String d1 = computeDigestDefective("bob", "realm", "s3cr3t", log1);
        String d2 = computeDigestFixed("bob", "realm", "s3cr3t", log2);
        check("fixed and defective produce identical digest response (fix is behaviour-neutral)",
            d1.equals(d2));
    }

    static void testPasswordNotLeakedForMultipleRealms() {
        String[] realms = {"api.example.com", "admin.local", "iot-gateway"};
        for (String realm : realms) {
            LogCollector log = new LogCollector();
            computeDigestFixed("user", realm, "TopSecretPW", log);
            check("password not logged for realm '" + realm + "'",
                !log.containsText("TopSecretPW"));
        }
    }

    // --- 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("=== EspIdf0002Test (CWE-312 HTTP auth password logged) ===\n");

        testDefectiveLogsPassword();
        testFixedDoesNotLogPassword();
        testDefectiveAlsoExposesUsername();
        testFixedProducesNoLogLines();
        testBothReturnSameDigest();
        testPasswordNotLeakedForMultipleRealms();

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